chapter 130 Hypospadias

Warren T. Snodgrass, MD

Hypospadias is believed to result from arrested penile development, leaving a proximal urethral meatus. It has challenged generations of reconstructive surgeons trying to extend the urethra while straightening associated penile curvature and managing ventral skin deficiency, with the goal of restoring as normal function and appearance as is possible. The current understanding of the etiology of hypospadias and current methods for its surgical correction are discussed in this chapter.

An emphasis is given to those procedures most commonly used today, and this selection inevitably omits some techniques that a minority of surgeons prefers. For example, meatoplasty and glansplasty (MAGPI) and Mathieu flip-flap are not discussed in detail, but technical aspects of these procedures have not significantly changed since their description in prior editions of this textbook.

Objective outcomes data are provided for described techniques to the extent available, usually summarized in the tables. Total complications may exceed the number of patients with complications due to multiple problems in some patients. Numbers appear only in columns designating outcomes specifically mentioned by authors.

Embryology of Penile Development

The external genital anlage is initially indifferent and develops the female phenotype unless exposed to androgens during the critical gestational time period of 8 to 12 weeks. 5α-Reductase type 2 is highly expressed in mesenchymal stroma while the androgen receptor is concentrated in epithelium of the urethral plate (Kim et al, 2002). Dihydrotestosterone derived from 5α-reduced testosterone mediates the key steps in penis formation: elongation of the genital tubercle and fusion of urethral folds.

The urethral plate develops as an extension of endoderm from the cloaca along the ventral midline of the genital tubercle. Proliferating mesenchyme to either side creates urethral folds and establishes the urethral groove. Fusion of the urethral folds begins proximally and continues distally at least to the glans. Two theories are proposed for glanular urethra development: ectodermal ingrowth cannulating the glans to the urethral plate (Glenister, 1954) versus urethral plate tubularization to the tip of the glans (Kurzrock et al, 1999).

Embryo studies suggest the penis initially exhibits ventral curvature (VC) during formation, which can persist in hypospadias when normal development arrests (Kaplan and Lamm, 1975). This VC originally was ascribed to fibrous tissue bands. However, histology from both embryos and resected surgical specimens demonstrate well-vascularized tissues without fibrosis (Baskin et al, 1998; Snodgrass et al, 2000).

Preputial development begins with a cellular lamella oriented dorsally at the coronal sulcus, with ventral fusion into the frenulum delayed until after urethral formation is completed.

Neither the molecular mechanisms involved in normal penis development nor those disturbances resulting in hypospadias are currently known. In mice, Sonic hedgehog (Shh) expressed by distal urethral plate epithelium is needed for genital tubercle outgrowth, with targeted deletion resulting in penile and clitoral agenesis (Haraguchi et al, 2001). Shh regulates fibroblastic growth factor-8 (fgf8), also known as androgen-induced growth factor, which upregulates expression of fgf10 involved in glans morphogenesis. Fgf10 also is expressed in midline mesenchyme during urethral fold fusion (Haraguchi et al, 2000), and deficient mutant mice exhibit a hypospadias-like phenotype that Yucel and associates (2004) believe indicates its crucial role in distal urethral plate tubularization. Fgf receptor 2 (Fgfr2) similarly is expressed in the urethral plate and prepuce in mice, and mice lacking it manifest proximal hypospadias (Petiot et al, 2005). Androgen receptor antagonists result in loss of Fgf10 and Fgfr2 expression in the urethra and hypospadias phenotype, indicating these genes are downstream targets involved in urethral formation (Petiot et al, 2005). The B-subclass of cell-surface Ehp and ephrin molecules also plays an important role in murine urethral formation, with heterozygous mutant males demonstrating perineal hypospadias (Yucel et al, 2007).

However, extrapolation of these findings in mice to human development is currently uncertain. Although Baskin and coworkers (2004) state the murine urethra tubularizes proximally to distally by urethral fold fusion similar to humans, others describe canalization of the urethral plate without fusion of urethral folds in rats and mice (Uda et al, 2004).

Etiology

The underlying cause for nonsyndromic hypospadias in most individual cases is unknown. Based on knowledge of normal penis formation and the presumption that hypospadias represents arrested development, several causes may exist.

Genetic Factors

Familial aggregation is found in 4% to 10% of hypospadias cases, including first-, second-, and third-degree relatives (Calzolari et al, 1986; Harris and Beaty, 1993; Fredell et al, 2002; Schnack et al, 2008). A recent national registration-based study from Denmark (Schnack et al, 2008) included 1.2 million males with 5380 hypospadias cases, reporting hypospadias equally transmitted through maternal and paternal sides of the family, with recurrence risk ratios similar for twin brothers, brothers, and sons. Difficulties in establishing recurrence risks include heterogeneity in the severity of hypospadias in probands, reliance on family histories introducing recall bias, and inclusion of patients with unrecognized syndromal hypospadias (Harris and Beaty, 1993; Schnack et al, 2008). Despite these limitations, a consistent conclusion is that familial aggregation is best explained by genetic factors rather than environmental exposure (Calzolari et al, 1986; Stoll et al, 1990; Schnack et al, 2008).

Endocrinopathies

The pivotal role of androgens in normal penis development suggests endocrinopathies impacting hormone production or action may underlie hypospadias. Leydig cell dysfunction was implicated by findings of elevated basal luteinizing hormone and reduced testosterone response to human chorionic gonadotropin stimulation in prepubertal boys with hypospadias versus controls (Nonomura et al, 1984). Defects in the testosterone biosynthetic pathway, specifically, impaired 3β-hydroxysteroid dehydrogenase alone or with impaired 17,20-lyase or 17α-hydroxylase activity, were reported in proximal hypospadias (Aaronson et al, 1997) but not confirmed in subsequent studies (Feyaerts et al, 2002; Holmes et al, 2004). Although enzymatic assays for 5α-reductase type 2 activity in isolated hypospadias are normal, mutations in its coding gene SRD5A2 on chromosome 2 were reported in 9% of patients with hypospadias not found in controls (Silver and Russell, 1999). Androgen receptor gene mutations are considered a rare cause of hypospadias (Batch et al, 1993; Hiort et al, 1994; Allera et al, 1995; Sutherland et al, 1996) but were not detected by others (Feyaerts et al, 2002).

Problems linking disturbed androgen activity to hypospadias were summarized by Holmes and associates (2004): little evidence has been found to suggest that nonsyndromic hypospadias without other genital anomalies is associated with defects in testosterone production, its conversion to dihydrotestosterone, or androgen receptor activity. Furthermore, the autosomal recessive pattern of inheritance characterizing steroidogenic enzyme disorders does not correlate with the genetics of hypospadias.

Endocrine Disruptors

A hypothesis that natural or synthetic compounds exerting estrogen-like and/or antiandrogen effects could result in hypospadias potentially is supported by several observations. First are reports that the incidence of hypospadias is increasing in Western nations where exposure to industrial compounds is presumed widespread. In addition, pregnant animals exposed to various chemicals in pesticides exerting estrogen-like or antiandrogen effects produce male offspring with urogenital anomalies, including hypospadias (Gray et al, 2004). Similarly, an increased risk for hypospadias has been identified in males after assisted reproduction, possibly attributable to progesterone administered to mothers. Finally, there is recognition that the estrogen receptor influences androgen activity as mentioned earlier, suggesting exposure to estrogen-like compounds may explain abnormal masculinization in the absence of demonstrated defects in testosterone production, 5α-reductase type 2 activity, or the androgen receptor.

However, although human penis development is potentially vulnerable to endocrine disruption, to date xenobiotics have not been linked to hypospadias (Baskin et al, 2001; Safe, 2005). Furthermore, the reported increase in hypospadias that suggests environmental endocrine disturbance has been challenged by recent epidemiologic studies (see later).

Syndromes with Hypospadias

Nearly 200 syndromes are associated with hypospadias (Edery, 2007).

Smith-Lemli-Opitz syndrome results from autosomal recessive mutation of the DHCR7 gene on chromosome 11q13 coding for 7-dehydrocholesterol reductase. Affected individuals have mental retardation, facial dysmorphism, microcephaly, and syndactyly. DHCR7 regulates Sonic hedgehog signaling, and so association of this syndrome with hypospadias potentially links to observations in mice regarding the role of Shh in penis development.

Deletion in chromosome 11q13 results in WAGR syndrome (Wilms tumor, Aniridia, Genital anomalies, mental Retardation), associated with hypospadias due to altered WT1 gene activity. One study screening for WT1 gene defects in boys with nonsyndromic hypospadias reported no mutations (Nordenskjold et al, 1999).

Hand-foot-genital syndrome is an extremely rare autosomal dominant condition due to mutations in HOXA13 on chromosome 7p14-15, resulting in bilateral thumb and great toe hypoplasia. Hypospadias in mice mutant for Hoxa13 also have loss of Fgf8 and bone morphogenetic protein-7 in the urethral plate (Beleza-Meireles et al, 2007a).

Opitz G syndrome (Opitz G/BBB syndrome) occurs from X-linked mutations in midline 1 gene or autosomal dominant deletions in chromosome 22q11. The resultant phenotype includes hypertelorism, tracheoesophageal defects, cleft lip/palate, and mild mental retardation as well as hypospadias.

Wolf-Hirschhorn syndrome derives from deletions in chromosome 4p, resulting in mental retardation, seizures, abnormal facies, and midline defects, including hypospadias.

13q deletion syndrome is characterized by mental retardation, facial dysmorphia, imperforate anus, and hypospadias with penoscrotal transposition. The critical region mediating anorectal and genital anomalies has been localized to 13q33.1-34, containing 20 annotated genes including EFNB2 (Garcia et al, 2006). Partial loss of ephrin B-2 function altering ephrin signaling in mice is associated with hypospadias, as discussed earlier.

Epidemiology

Prevalence

In the 1800s both Bouisson and Rennes reported that hypospadias occurred in 1 of 300 males (Beck, 1917). Data from birth registries in the United States during the late 1960s demonstrated a similar incidence (Paulozzi et al, 1997). Subsequent studies in the 1970s and 1980s indicated an apparent doubling in hypospadias occurrence in the United States, Hungary, and England, with upward trends in Denmark, Norway, and Sweden (Paulozzi et al, 1997; Aho et al, 2000a; Toppari et al, 2001). A simultaneous increase in the ratio of severe to mild forms of the condition in the Metropolitan Atlanta Congenital Defects Program suggested the increase was due to growing incidence rather than to more frequent reporting of distal cases (Paulozzi et al, 1997). Together these data from national birth registries have been taken as evidence for the influence of environmental toxins.

However, a review of surgically treated cases versus live births in Finland from 1970 to 1986 found prevalence of hypospadias unchanged despite the apparent increase noted in the national malformation registry (Aho et al, 2000a). Further investigation suggested hypospadias was previously underreported in the Finnish national malformation registry, as well as in Swedish and Danish registries (Kallen et al, 1986). Therefore, the apparent increase in hypospadias rate in these countries may only indicate changes in reporting.

In addition, various national databases have differences in reporting requirements. For example, in Australia and Japan only cases with the urethral opening on the penile shaft, scrotum, or perineum are registered, omitting the more common coronal and glanular forms (Toppari et al, 2001). Similarly, a comparison between surgical registries and the National Congenital Anomaly System in England found significant disparity in hypospadias rates attributed to a decision in 1990 to exclude reporting of distal cases (Nelson et al, 2007). Consequently, data from such registries cannot be used to accurately determine either incidence of hypospadias or geographic variations in its occurrence.

Diagnosis

Hypospadias is diagnosed by physical examination, first suspected by the ventrally deficient prepuce and confirmed by the proximal meatus (Fig. 130–1). Other abnormal ventral findings potentially include downward glans tilt, deviation of the median penile raphe, VC, scrotal encroachment onto the penile shaft, midline scrotal cleft, and penoscrotal transposition.

A variant subset has a normally formed foreskin concealing a glanular to distal shaft hypospadias termed megameatus intact prepuce (MIP) (Fig. 130–2). Diagnosis is made after elective neonatal circumcision or in later childhood when the foreskin retracts.

Patients with ventrally deficient foreskins but a normally located urethral meatus are diagnosed as having chordee without hypospadias. The term implies ventral penile curvature, although, in the majority, apparent downward bending is corrected by simply degloving the ventral skin. This categorization has included patients with a glanular meatus but deficient corpus spongiosum and thin distal urethra that others consider hypospadias variants. To end confusion, boys with a hooded prepuce and bending should be diagnosed with congenital ventral curvature if the urethra is grossly normal or otherwise with hypospadias (Snodgrass, 2008).

Associated Anomalies

Cryptorchidism

Retrospective chart reviews (Kaefer et al, 1999; Wu et al, 2002) and a case-control study from the Danish National Patient Register (Weidner et al, 1999) report that approximately 7% of hypospadias patients also have cryptorchidism. In a series of 356 patients with hypospadias the incidence of cryptorchidism was 3.4% of 88 with distal versus 10% of 234 with proximal hypospadias (Wu et al, 2002).

Disorders of Sex Development

Although hypospadias is considered arrested masculinization, by convention it is distinguished from DSD. As discussed earlier, defects in testosterone production, its conversion to dihydrotestosterone, or androgen receptor activity that characterizes various disorders of sexual differentiation are uncommonly detected in isolated hypospadias.

The simultaneous occurrence of hypospadias with cryptorchidism increases the likelihood for DSD. Overall reported incidence in patients considered to have a male-appearing phenotype ranges from 0% to 30% and is greater with increasing severity of hypospadias and nonpalpable testes (Rajfer and Walsh, 1976; Kaefer et al, 1999; McAleer and Kaplan, 2001; Cox et al, 2008). Kaefer and colleagues reported DSD in approximately 50% of patients with a nonpalpable testis and hypospadias.

The most frequent finding is mixed gonadal dysgenesis, followed by ovotesticular disordered sexual differentiation. Incomplete androgen insensitivity, 5α-reductase type 2 deficiency, and testicular dysgenesis have also been reported. However, likely differences in defining male appearance versus ambiguity and failure to perform uniform genetic, biochemical, and radiologic evaluation in hypospadias patients with cryptorchidism make determination of the incidence of DSD uncertain.

Coexistence of hypospadias and cryptorchidism can be explained by other associations than DSD. For example, a case-control study examining risk factors independently for the two conditions within the same nationwide cohort in Sweden found low birth weight and prematurity positively correlated with each (Akre et al, 1999).

Preoperative Evaluation and Management

Radiologic Studies

No prospective studies report the incidence of radiologically detected urinary tract anomalies associated with hypospadias. Initial retrospective reviews concerned intravenous pyelography, and of these the largest series found upper tract anomalies are not increased with nonsyndromic hypospadias (McArdle and Lebowitz, 1975; Lutzker et al, 1977; Cerasaro et al, 1986). Routine voiding cystourethrography to demonstrate an enlarged utricle is not necessary, because the most common clinical manifestation is difficult catheterization that can be managed intraoperatively. Imaging can be reserved for screening patients with suspected syndromic hypospadias or DSD.

Timing of Surgery

There are no data regarding optimal timing for hypospadias surgery in children, and so guidelines are derived from expert opinion. The 1996 action committee for the American Academy of Pediatrics Section on Urology reviewed psychological factors, anesthetic considerations, and technical aspects of hypospadias repair before recommending surgery be performed between 6 and 12 months, assuming the surgeon, anesthesiologist, and facility were experienced in the care of infants (American Academy of Pediatrics, 1996). Same-day surgery can be performed after 50 gestational weeks in otherwise healthy boys, leading the author to routinely recommend repair at 3 months of age or older for distal hypospadias and selected proximal cases with an apparently normal-sized phallus. Infants with proximal hypospadias and a small-appearing glans are reassessed at 3 months and then administered hormonal stimulation, as discussed later, before surgery at approximately 6 months of age.

Optimal timing for surgery in children presenting at an older age is uncertain. From 18 months to approximately 3 years of age has been described as a difficult period for hospitalization, leading to a recommendation that repair be postponed to age greater than 3 years (Manzoni et al, 2004). However, the American Academy of Pediatrics action committee observed that surgery from 30 to 65 months of age may increase the child’s anxiety for physical injury. One study compared health-related quality of life assessment after hypospadias surgery done at less than 18 months of age versus more than 18 months of age and found no differences related to age at operation (Weber et al, 2008). Preoperative sedatives, minimal separation from family, same-day surgery, anesthetic blocks that reduce early postoperative pain, dressings that fall off spontaneously, and urinary diversion into diapers all may reduce psychological stress from hypospadias repair.

Preoperative Hormonal Stimulation

Androgenic stimulation has been advocated to increase penile size, reduce VC, and improve vascularity. Although several reports involving small numbers of patients with varied severity of hypospadias document increased penile size, glans circumference, and/or transverse length of the inner prepuce, no prospective randomized trial has determined that hormonal therapy favorably impacts objective surgical outcomes. Furthermore, no available data establish mean and standard deviations for normal glans size in children of varying ages.

One reported regimen is intramuscular testosterone enanthate 2 mg/kg given 5 and 2 weeks preoperatively (Gearhart and Jeffs, 1987; Luo et al, 2003). A comparison between a mixture of testosterone propionate and enanthate providing a dose of 2 mg/kg/wk administered twice daily topically or intramuscularly weekly found no differences in response regarding penile length or diameter. Elevated serum levels greater than 10 ng/mL only were noted after topical therapy, possibly from excessive application (Chalapathi et al, 2003).

Reported mean increases in penile length range from approximately 0.5 to nearly 3 cm, with partial to complete loss of these gains by 3 to 12 months after stimulation (Gearhart and Jeffs, 1987; Davits et al, 1993; Chalapathi et al, 2003). Side effects include pubic hair growth and aggressive behavior; accelerated linear height and bone age have not been documented (Gearhart and Jeffs, 1987; Davits et al, 1993; Chalapathi et al, 2003), but few patients have had bone age assessed after stimulation.

The author prefers two to three intramuscular injections of testosterone enanthate 2 mg/kg over a 6- to 12-week period. Hormonal stimulation has been used in less than 1% of distal repairs versus 25% of proximal to perineal cases and is recommended when the glans appears small, recognizing there are no published criteria to define normal or adequate glans diameter (Snodgrass and Yucel, 2007).

General Aspects of Surgical Repair

Postoperative Urinary Diversion

One RCT randomized 64 toilet-trained boys (median age 6 years, range 2 to 17) undergoing tubularized incised plate (TIP) repair by a single surgeon to postoperative bladder catheterization or not, decided at the conclusion of the procedure. There were no differences in urethroplasty complications; however, dysuria (14% vs. 45%, P < .01), urinary retention (0% vs. 24%, P < .05), and urinary extravasation (0% vs. 17%, P < .05) occurred significantly more often in the unstented group (El-Sherbiny, 2003).

A prospective observational study by the same surgeon involved 32 consecutive non–toilet-trained boys (mean age 18 ± 6 months) undergoing TIP repair with no urinary diversion. Urinary extravasation developed in one patient the second postoperative day resulting in catheter placement. There were no urethroplasty complications with mean follow-up of 9 months (Almodhen et al, 2008).

Another prospective study compared 36 patients undergoing Mathieu repair with catheter (n = 17, mean age 4.1 years) versus without diversion (n = 19, mean age 4.6 years) and no difference was reported in urethroplasty complications at 6 months or longer follow-up (McCormack et al, 1993).

The author prefers urinary diversion to avoid the occasional need for early postoperative catheterization due to retention or extravasation. However, should the catheter inadvertently be dislodged prematurely it is not replaced unless urinary retention or extravasation occurs. A 6-Fr bladder stent is used for all repairs in prepubertal boys regardless of age, or a 12- to 14-Fr catheter is used in patients after puberty.

Dressings

Two RCTs, one having 100 patients operated on by one surgeon (Van Savage et al, 2000) and the other comprising 120 patients and four surgeons (McLorie et al, 2001), were done to evaluate the role of postoperative bandages. In the first study patients had an adhesive film versus no dressing, whereas the second compared postoperative topical antibiotic ointment alone to an adhesive film or compressive wrap followed by topical antibiotic ointment applied after dressing removal. In both, 2% of patients were excluded from randomization owing to bleeding at the conclusion of the procedure resulting in a bandage. Parents in both studies were instructed to remove the bandage by postoperative day 2 (Van Savage et al, 2000) or when it appeared loose (McLorie et al, 2001). Neither study reported the appearance of the penis on catheter removal (e.g., extent of edema or hematoma formation). Urethroplasty outcomes were not impacted by dressings versus no dressings. Both studies noted greater numbers of telephone calls from parents of boys with bandages, although one did not state if these calls specifically related to the dressing.

Both these studies concluded that bandages are not needed after hypospadias repair, and when they are used they increase parental anxiety. However, in both, parental concern also might relate to instructions to remove the dressings. McLorie and colleagues (2005) specifically noted that half the parents did not remove the bandage as instructed and that 38% of boys with adhesive films and 82% with compressive wraps experienced pain with dressing removal.

The lack of benefit to compressive wrap dressings and the greater likelihood of discomfort for the child with their removal argues against their use. Otherwise, in both studies a major argument against dressings is the bother for parents in removing them. Because adhesive films nearly always fall off spontaneously, surgeons who prefer bandages might consider their use—combined with assurances that the parents need not be concerned with dressings.

Historic Background

Although it is commonly written that more than 200 repairs have been described, hypospadias urethroplasty can be summarized into three basic categories: tubularization of the urethral plate, supplementation or substitution of the urethral plate with skin flaps, or urethral plate substitution with grafts (Fig. 130–3). Of these, today the most common primary surgery is urethral plate tubularization. This is also the most recently introduced concept, given that the urethral plate—tissues extending distally from the hypospadias meatus that normally form the urethra—was only recognized as a distinct structure in the late 1980s.

Hypospadias surgery that began in the early 1800s originally focused on repair for proximal defects. VC often found in these cases was ascribed to fibrous bands, and by the 1940s the belief that these fibrous tissues represented dysplastic corpus spongiosum extending fanlike from the meatus became firmly entrenched. This “chordee tissue,” now recognized as the urethral plate, was resected for straightening. Consequently, substitution urethroplasty was necessary, most often accomplished using preputial flaps. Variations of these flaps account for most of the different repairs described.

Modern hypospadias surgery dates to 1980. Duckett (1980) mobilized inner preputial flaps on a vascular pedicle away from dorsal shaft skin, providing greater flexibility to transpose them ventrally. The following year he described the meatoplasty and glanuloplasty (MAGPI) technique for glanular defects (Duckett, 1981), opening the door for routine distal repair that today comprises most hypospadias surgery. It was also Duckett who defined the urethral plate and then modified his tubularized preputial flap (“transverse island”) to the onlay version supplementing, rather than substituting, the plate after realizing routine “chordee” excision was not necessary (Baskin et al, 1994). By the end of the decade nearly all primary hypospadias could be repaired using MAGPI, onlay, or tubularized preputial flaps.

Although tubularization of the broad or deeply grooved urethral plate had been reported sporadically, in 1994 the midline incision was described to tubularize the narrow or flat plate without the need for supplemental skin flaps (Snodgrass, 1994). The TIP repair subsequently gained widespread use for its perceived simplicity and improved cosmetic outcomes versus flap repairs. Its application to proximal hypospadias followed increased realization that the urethral plate is not fibrous scar but well-vascularized tissues that potentially can be preserved for urethroplasty, even in some cases with VC.

Hypospadias Surgery

Ventral Curvature

Etiology

The penis exhibits VC during normal development (Kaplan and Lamm, 1975), which implies that persistent bending in hypospadias reflects arrested development. Consequently, ventral tissues—including shaft skin, dartos, corpus spongiosum, urethral plate, and overlying tunics of the corpora cavernosa—may be shortened relative to the dorsal surface. Previous concepts that dysplastic dartos and corpus spongiosum coalesce into fibrous “chordee” tissues that require resection have been disproved by histologic studies in both embryos and surgical specimens referenced earlier (Baskin et al, 1998; Snodgrass et al, 2000).

Preoperative and Intraoperative Assessment

Preoperative assessment cannot accurately predict either the extent of curvature or the means required for straightening. Apparent bending may improve or resolve as the skin is degloved, so the common maneuver of compressing penopubic and penoscrotal tissues at the base of the penis to better visualize the penile shaft may falsely suggest or exaggerate VC by traction on deficient ventral skin. The finding that skin adjacent to the meatus may retract as far as the penoscrotal junction during degloving provides additional proof that relatively short ventral skin contributes to curvature.

Cephalad traction on the glans stay suture causes the bent (>30 degrees) penis to pivot from side to side. Such observations formed the basis for determining VC and its correction until saline corporeal injection was described by Gittes and McLaughlin in 1974. Artificial erection induced by saline injection remains the most commonly used means to assess presence and severity of VC, as well as to document successful correction. Criticisms of the technique include the potential for supraphysiologic or subphysiologic intracorporeal pressure during injection to distort findings. After ventral dissection of tissues from the tunica albuginea and/or ventral lengthening procedures for the corpora cavernosa (see later discussion), repeat erection may be difficult, owing to corporeal leakage.

Vasoactive drugs have also been injected to induce erection during hypospadias repair (Perovic et al, 1997; Kogan, 2000), with the proposed advantage being more physiologic assessment in contrast to saline injection. However, dose regimens are empirical in children, erection lasts longer than with saline irrigation unless a reversal agent is injected, and there may be increased bleeding from the prolonged erection.

It should also be noted that reported degrees of curvature, including those by this author, most likely were subjectively determined by visual estimate without direct measurement with a protractor.

Straightening Maneuvers

Curvature up to 30 degrees can be corrected by midline dorsal plication into the tunica albuginea of the corpora cavernosa directly opposite the area of greatest bending (Fig. 130–4). Baskin and colleagues (1998) reported lack of sensory nerves in this location, and straightening without corporotomy can be achieved.

There are few reports concerning sutures used, efficacy, or durability of plication, and assessment is complicated by lack of objective determination of intraoperative and postoperative extent of curvature. The only outcomes data for midline plication to date are found in a retrospective review of 43 prepubertal boys, 53% with VC greater than 30 degrees, whose curvature was straightened using one or two polypropylene 4-0 or 5-0 sutures. At median 16 months’ follow-up, 93% of patients were thought to maintain a straight penis (Bar Yosef et al, 2004). In contrast, the author uses only a single 6-0 polypropylene suture for midline plication of bending less than 30 degrees, preferring alternative methods to multiple plications when curvature is greater.

Similarly, optimal management of VC greater than 30 degrees remains uncertain. Multiple plications using 5-0 to 4-0 polypropylene are described, although concerns for both recurrent curvature and loss of penile length increase when more than one plication is performed (Braga et al, 2008). This extent of bending after skin degloving and ventral dartos dissection is considered disproportion between the ventral and dorsal aspects of the corpora cavernosa (Baskin et al, 1994). Ventral lengthening traditionally involves transection of the urethral plate followed by transverse incision from the 3- to 9-o’clock position into the tunica albuginea to expose erectile tissues of the corpora in the region of greatest curvature. The resultant defect has been closed using dermal grafts, small intestine submucosa, or tunica vaginalis flaps or grafts (Fig. 130–5). No evidence indicates the outcome is significantly influenced by choice of materials for corporotomy repair. Most proponents of the use of small intestine submucosa have used single-layer material; use of four-layer small intestine submucosa was reported in two small series and was associated with recurrent curvature in one (2 of 12 cases) (Soergel et al, 2003) but not in another (0 of 21 cases) (Elmore et al, 2007).

Urethral plate transection to facilitate corporeal grafting requires substitution urethroplasty using preputial flaps or grafts in either one or two stages. Alternatively, the urethral plate and adjacent corpus spongiosum can be preserved and dissected from the underlying surface of the corpora cavernosa. Elevation of the plate alone has been reported to correct curvature (Mollard and Castagnola, 1994), or it can be combined with corporotomy and grafting (Kajbafzadeh et al, 2007). Dissection under the urethral plate can also be continued proximally to near the membranous junction, elevating the normal urethra from the corpora (Fig. 130–6). This maneuver was adapted from urethral stricture repair in which mobilization of the urethra combined with its inherent elasticity allows gaps to 5 cm in adults to be bridged (Warwick et al, 1997). After dissection of the urethral plate and urethra, residual VC can be corrected by dorsal plication or ventral corporotomy (Riccabona et al, 2003; Bhat, 2007; Snodgrass and Prieto, 2009). Rather than a single corporotomy with grafting, two to three transverse incisions can be made into the tunica albuginea without exposing erectile spongy tissue or need for grafting (see Fig. 130–5) (Devine, 1983; Snodgrass and Prieto, 2009). The preserved urethral plate can then be incorporated into TIP repair or onlay urethroplasty.

VC that persists despite mobilization of the urethral plate and urethra requires urethral plate transection for straightening. In the author’s experience 15 patients with penoscrotal to perineal hypospadias have undergone urethral plate elevation alone (3 patients) or combined with urethral mobilization (12 patients), of which 3 patients had persistent bending despite dissection to the membranous region, visibly due to tethering by a short urethral plate (Snodgrass and Prieto, 2009).

A proposed algorithm for correcting penile curvature is outlined in Figure 130–7.

Urethroplasty

The most commonly used options for primary hypospadias urethroplasty are summarized in Figure 130–8. It is traditional to describe repairs in separate categories for distal, midshaft, and proximal defects based on meatal position after skin degloving and correction of VC, although an alternative classification would be to consider primary repairs accomplished by tubularizing the urethral plate versus options when the plate is not maintained for urethroplasty (Sozubir and Snodgrass, 2003), most notably when VC greater than 30 degrees results in plate transection.

Distal Hypospadias

The most commonly performed operation to repair distal hypospadias is the TIP repair. Although other procedures such as MAGPI, Mathieu flip-flap, and urethral advancement remain in use, a survey of current practices indicates these together account for less than 10% of distal procedures (Cook et al, 2005). Technical aspects of these operations are little changed from prior descriptions in this textbook, with the exception of V incision into the ventral lip of flip-flaps, which attempts to create a vertical meatus (Boddy and Samuel, 2000). However, a study correlating preoperative configuration of the urethral plate (deep vs. moderate or shallow groove) to cosmetic results after V incision into onlay preputial flaps questions the reliability of this maneuver to achieve a vertical neomeatus unless the plate already is deeply grooved (Hayashi et al, 2007).

Figure 130–9 depicts TIP repair. The key step is midline incision of the urethral plate, which widens a narrow plate and converts a flat into a deep plate groove (Fig. 130–10), ensuring a vertical, slit neomeatus and a normal-caliber neourethra. Tubularization should not continue beyond approximately the midpoint of the dissected glans wings, corresponding to a point some 3 mm proximal to the distal extent of the plate, to avoid iatrogenic meatal stenosis. Glansplasty approximates the glans halves distally to create a normal-appearing meatus independent of plate tubularization (Fig. 130–11), because the opening of the urethral plate is not sutured to the glans as is commonly done with flaps.

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Figure 130–9 Distal tubularized incised plate repair. A, Circumscribing incision is made approximately 2 mm below meatus when circumcision is desired. B, Ventral V incision when foreskin reconstruction is planned. C, Penis degloved (or only ventral surface exposed during foreskin preservation). Visible junction of glans wings to urethral plate is marked and then infiltrated with 1 : 100,000 epinephrine. D, Midline incision of the urethral plate extends from within the meatus to the end of the plate, without entering the distal glans. Incision continues to near the corpora cavernosa. E, Urethral plate tubularization begins distally approximately 3 mm from the end of the plate, ensuring an oval, not rounded, meatus. Subepithelial running 7-0 polyglactin sutures proceed proximally. A knot is tied, and then suturing returns distally to complete a two-layer closure. F, Dartos flap is dissected from the dorsal prepuce and shaft skin, buttonholed, and transposed ventrally to cover the neourethra. A flap can usually be developed from the ventrolateral dartos in patients undergoing foreskin reconstruction G, Glansplasty begins distally, and a 7-0 polyglactin suture is used to create the meatus at the desired location, independent of the underlying urethral plate tubularization. A second 7-0 polyglactin suture under the first reinforces this distal approximation. Then a single layer of 6-0 polyglactin interrupted subepithelial sutures completes the glans wings closure to the corona. H, Shaft skin closure for circumcision after excising excess prepuce and approximating the inner preputial collar ventrally. Interrupted subepithelial 7-0 polyglactin is used. I, Foreskin reconstruction performed in three layers using 7-0 polyglactin sutures: inner prepuce, dartos, and outer shaft skin are separately approximated using subepithelial 7-0 polyglactin.

(Reprinted from Snodgrass WT. Snodgrass technique for hypospadias repair. BJU Int 2005;95[4]:683–93.)

Contraindications

Whether urethral plate characteristics (flat vs. deeply grooved, narrow vs. wide) determine the appropriate use of TIP repair has been debated. Some consider a flat and/or narrow urethral plate a contraindication to TIP repair (Holland and Smith, 2000), whereas others report TIP repair reliably corrects distal hypospadias regardless of urethral plate configuration (Nguyen and Snodgrass, 2004). The author has not found an alternative procedure necessary for distal hypospadias repair in over 500 consecutive cases (Snodgrass et al, 2010).

Outcomes

Table 130–2 summarizes published short-term results for TIP distal urethroplasty. The longest reported mean follow-up is 2 years, and to date no series describes outcomes after puberty in patients operated on when children.

Table 130–2 Distal Tubularized Incised Plate (TIP) Repairs

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One purported advantage to the TIP repair over alternative procedures for distal hypospadias is improved appearance of the meatus, creating a vertical slit neomeatus in contrast to the sometimes rounded configuration after Mathieu or other flap repairs. In addition to meatal shape, however, normal cosmesis requires sufficient glans approximation below the meatus to the corona so that the neomeatus appears correctly positioned. Two to three sutures closing the glans wings between the meatus and corona are needed and are readily placed in the TIP repair because glans closure is independent of urethral plate tubularization. In contrast, it may be difficult to mature the neomeatus created with flaps to glans wings and maintain sufficient glans to allow these additional two to three stitches proximally to the corona.

Two studies objectively assess cosmesis. One used postoperative photographs blindly scored by a panel of medical professionals that ranked TIP repair results superior to those from Mathieu and onlay flaps (Ververidis et al, 2005). A second administered Likert scale questionnaires to parents and the operating surgeon after TIP repair or circumcision. No significant differences occurred between surgeon and parents in either group or in satisfaction after TIP repair for hypospadias versus elective circumcision in boys with a normal penis (Snodgrass et al, 2008).

Midshaft Hypospadias

In a consecutive series of boys with midshaft hypospadias none had VC greater than 30 degrees, indicating the urethral plate can be maintained for urethroplasty in most cases (Snodgrass and Yucel, 2007). Accordingly, options for repair include TIP repair or onlay preputial flap. Technical aspects of TIP repair are unchanged from distal operations described earlier, with the addition that divergent corpus spongiosum can be dissected from the underlying corpus cavernosa and released from glans wings to approximate over the shaft portion of the neourethra to near the corona (Yerkes et al, 2000).

An onlay preputial flap is depicted in Figure 130–12. Thin skin proximal to the urethral meatus is incised to the midline convergence of corpus spongiosum wings. Then inner prepuce is harvested on its vascular pedicle from either the dorsal hood or from one side of Byars flaps after the dorsal hood is incised (Sedberry-Ross et al, 2007). The flap should be gently stretched to fit the urethral plate without redundancy. Distally, flaps are secured to the glans wings to create the neomeatus. The vascular pedicle or a separate dartos flap can be used to cover the exposed suture line.

Proximal Hypospadias

The greatest controversy in primary hypospadias surgery concerns decision making for proximal cases. Options depend on whether the urethral plate is available for urethroplasty after associated VC is straightened. If so, then either TIP repair or an onlay preputial flap can be used. When the urethral plate is transected a one-stage urethroplasty can be accomplished by tubularized preputial flaps or the Koyanagi flap or a two-stage repair done with Byars flaps or preputial grafts.

Tubularized Incised Plate Repair

Steps for a proximal TIP repair are illustrated in Figure 130–13. There are several important distinctions between distal and proximal TIP repairs. First, correction of VC may lead to dissection of the urethral plate, and proximal urethra, from the corpora cavernosa. Midline incision can still be performed without creating separate strips (see Fig. 130–6C). The neourethra is tubularized with interrupted subepithelial sutures reinforced by a second running layer. Divergent corpus spongiosum is next sewn over the neourethra, followed by a tunica vaginalis flap (Fig. 130–14). To reduce chances for secondary partial concealment of the penis, shaft skin at the penoscrotal junction is secured to the corpora cavernosa with subepithelial 5-0 polydioxanone to either side of the ventral midline before skin closure.

Outcomes

In a cohort of 56 boys with proximal shaft to perineal hypospadias, the author corrected 36 (64%) using the TIP procedure while the other 20 (36%) underwent staged repairs after urethral plate transection during straightening (Snodgrass and Yucel, 2007). After that report, urethral plate/proximal urethral dissection with superficial transverse corporotomies were incorporated into the algorithm for straightening, resulting in more frequent preservation of the plate. In 22 consecutive proximal shaft to perineal repairs, 19 (86%) had TIP repair versus only 3 (14%) undergoing a two-stage repair (Snodgrass and Prieto, 2009).

Urethroplasty complications occurred in 8 (53%) of the original 15 patients undergoing proximal TIP repair by the author, which were mostly fistulas in 5 (33%) despite a dartos flap over the neourethra in every case. After technical modifications described earlier (two-layer subepithelial tubularization and spongioplasty) the complication rate in the next 20 cases decreased to five complications (25%), including two (10%) fistulas. After substituting tunica vaginalis rather than dartos for the barrier layer, in the most recent 22 cases there were no fistulas, the single complication (4.5%) being glans dehiscence.

Table 130–3 shows other published results for proximal TIP repair, excluding those in which proximal outcomes cannot be distinguished from more distal cases. Selection bias must be considered in these reports, because none except the study of Yucel and Snodgrass states the total number of proximal cases operated during the study period to determine the relative use of TIP repair versus other techniques.

Table 130–3 Proximal Tubularized Incised Plate (TIP) Outcomes

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Tubularized Preputial Flap

This procedure is illustrated in Figure 130–15. After excision of the urethral plate and required straightening maneuvers, the required length of inner prepuce is harvested, tubularized, and transferred ventrally. The native urethra is secured to the corpora cavernosa and then spatulated before anastomosis to the flap to reduce incidence of stricture, and then the tube is gently stretched distally, with its suture line facing dorsally, and anchored to the corpora cavernosa with interrupted stitches. Glans wings are sewn to the flap to create the neomeatus.

Alternatively, the open flap is brought ventrally and then one side is secured to the corpora cavernosa just lateral to the midline with interrupted subepithelial sutures. The flap is gently stretched, excess tissues are excised, and then the other side is similarly anchored to the corpora to complete tubularization. This tube is tailored proximally to approximately the caliber of the native urethra before the anastomosis is made (Canning, 2007).

Koyanagi Flap

Use of the Koyanagi repair is determined from the outset of the operation based on the surgeon’s impression that VC will lead to urethral plate excision, and so decision making for this procedure differs from all others described in this section.

The Koyanagi repair updates the Russell operation (Russell, 1900), primarily by maintaining blood supply to the flaps as illustrated in Figure 130–16. These flaps are brought together ventrally, sewn into a single strip, and then tubularized proximally to distally.

Byars Flaps

A two-stage flap repair (Fig. 130–17) divides the dorsal preputial hood, transposes the resultant flaps ventrally, and reapproximates them in the midline from the native urethral meatus to the glans tip. Glans wings should be widely separated to allow sufficient skin to be placed for later tubularization. The author previously maintained the urethral plate within the glans to combine distal TIP repair with a proximal Byars flap urethroplasty (Snodgrass et al, 1998) but discontinued that approach due to complications (see later). After a period of approximately 6 months, second-stage tubularization of the skin flaps is accomplished.

Outcomes

Table 130–5 shows outcomes data for staged skin flap repairs. The largest series did not state the number of patients with follow-up or duration of follow-up. Nearly half the patients operated on by Greenfield and coworkers (1994) had midshaft or more distal hypospadias, all of which corrected by the Belt-Fuque technique, but outcomes were included because this is a two-stage preputial flap procedure.

Table 130–5 Two-Stage Preputial Flap Outcomes

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Cheng and colleagues (2003) transected the urethral plate proximally, preserving the distal portion, and used Byars flaps to bridge the gap to the native urethra. Diverticula formed in 2 of 14 patients from the interposed skin flaps without distal obstruction. The authors preserved the glanular urethral plate in eight of nine Byars flap repairs. The complication rate was 100%, including five diverticula and two strictures at the flap/urethral plate junction. Of the diverticula, four had no distal obstruction except for the presumed increased resistance to flow created by the glans. Considering diverticulum formation without obstruction evidence of preputial skin distensibility, another 4 patients had buccal grafts—thought less elastic—interposed between the distally preserved urethral plate and proximal native urethra, but a diverticulum still developed in one, leading the author to abandon these techniques.

Preputial Grafts

Inner prepuce can be harvested as a graft to bridge the defect from native urethra to glans tip when the urethral plate is excised. This approach has not been commonly used in the United States because curvature leading to urethral plate transection most often has been corrected by corporeal incision and grafting, meaning subsequent addition of a urethral graft would place one graft onto another. Preputial grafts are an option when remaining VC after urethral plate excision is less than 30 degrees or if multiple superficial transverse corporotomies are used for correcting VC without corporeal grafting.

The procedure is shown in Figure 130–18. After excision of the plate the ventral native urethra is sewn to surrounding skin edges to establish a proximal meatus, and the glans wings are widely opened. Inner prepuce is harvested, and the dartos is excised from its undersurface. Then it is secured to the dorsal lip of the native urethra and gently stretched distally. Sutures anchor it to adjacent shaft skin and glans wings, with subepithelial stitches used along the glans tip to avoid tracks at the neomeatus during the second stage. Additional rows of stitches “quilt” the graft to the corpora cavernosa to facilitate neovascularization by limiting fluid collection under the graft. A tie-over dressing further immobilizes the graft during the first week of healing. Six months later this neourethral plate is tubularized and covered with tunica vaginalis.

Outcomes

Cloutier described two-stage grafting in 1962, but Bracka is credited with stimulating modern interest in this approach. His report (Bracka, 1995) mixes primary cases of all extents with reoperations, and so data specifically for primary proximal hypospadias are not available. Of the three publications summarized in Table 130–6, two similarly combine data mostly from midshaft to distal repair with results from a smaller number of proximal hypospadias. Only the report by Ferro and colleagues (2002) focused on proximal repairs using Bracka’s technique. In all these, complications from grafting occurred in less than 5%, consisting of partial graft loss that did not require an additional procedure for correction before second-stage tubularization.

Table 130–6 Two-Stage Grafts

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Skin Closures

Inner Preputial Collar

The ventral preputial deficiency found in most hypospadias patients includes its inner “mucosal” surface, which normally provides coverage between the corona and shaft skin. Instead, shaft skin occupies the space from the margins of the open glans wings to the urethral plate and meatus. To create the appearance of a normal circumcised penis, this shaft skin must be removed and ventral midline closure done using inner prepuce transposed from the dorsal hood. Firlit (1987) described a chevron incision dorsally to create bilateral “darts” for ventral midline approximation (Fig. 130–19).

Although it has been suggested that divergence between the darts may preclude midline approximation, necessitating rotational flaps (Redman, 2006), the author has not encountered this situation. The proximal corners of the darts are first approximated using a 7-0 polyglactin subepithelial suture, which then provides ventral traction. Midline closure proceeds distally with interrupted subepithelial stitches. The space immediately below the glans is repaired using 9-0 polyglactin stitches placed through the epithelium. The postoperative appearance with the mucosal collar is contrasted to examples in which the collar was not formed, illustrating the importance of this step for optimal cosmetic outcomes (Fig. 130–20).

Circumcision versus Foreskin Reconstruction

The abnormal prepuce can be removed for circumcision or reconstructed ventrally if a natural, nonoperated appearance is preferred. For circumcision, a circumferential skin incision is made initially, creating lateral darts to approximate the mucosal collar ventrally, as described in the preceding section. When foreskin reconstruction is desired, the initial skin incision extends in a V from the corners of the dorsal prepuce ventrally to below the meatus, without a circumferential incision.

In patients to be circumcised, after completion of urethroplasty, glansplasty, and ventral mucosal collar the dorsal prepuce is incised in the midline proximally to the level of the mucosal collar and then stitched to it with a subepithelial 7-0 polyglactin suture. Next, the ventral median raphe is approximated from proximally to near the mucosal collar using interrupted subepithelial sutures. Excess lateral skin is excised and remaining skin edges are closed with subepithelial sutures to minimize the likelihood of suture tracks (Snodgrass, 1999a).

Foreskin repair begins with subepithelial closure of the inner surface with the dorsal foreskin retracted proximally. Then the prepuce is extended distally and the dartos approximated to reinforce closure of the inner layer. Finally, the outer skin margins are sutured together with subepithelial stitches, avoiding iatrogenic distal phimosis. The family is instructed not to retract the foreskin until the surgeon determines postoperatively that edema and tissue reaction have subsided, usually after 6 weeks.

Outcomes

Preputioplasty is an option in nearly all distal hypospadias surgeries, although occasionally the prepuce is too narrow to close ventrally. Foreskin reconstruction also can be considered for midshaft to proximal repairs, unless flap urethroplasty leaves insufficient skin. Although typically done without a circumscribing incision, when VC suggests need for dorsal plication the penis can be degloved with subsequent preputioplasty (Snodgrass et al, 2006).

Klijn and coworkers (2001) reported increased urethroplasty and skin complications with foreskin reconstruction versus circumcision during distal hypospadias repair, but these may have resulted from their reliance on skin flap (Mathieu) urethroplasty and their instructions to parents to begin foreskin retraction only 2 weeks postoperatively. In a comparison of matched cohorts undergoing distal TIP repair with foreskin reconstruction versus circumcision, Suoub and associates (2008) found no differences in urethroplasty or skin complications, which is also the experience of the author (unpublished data).

Minor and Major Scrotoplasty

Scrotal encroachment onto the ventral penile shaft can occur associated with any extent of hypospadias. This sometimes creates a false impression that the meatus is penoscrotal when it is actually found located on the distal shaft after penile degloving moves the scrotum proximally. Midline scrotal cleft and varying degrees of superolateral extension of scrotum alongside the penis most often are encountered in proximal hypospadias, in some cases combined with a rugated, feminized appearance at the dorsal penopubic junction. Collectively these findings are commonly referred to as penoscrotal transposition, although this term also describes the rare condition in which the penis is actually located completely below the scrotum.

Encroachment onto the penile shaft is corrected by release of the scrotum as the penis is degloved, with subsequent suture fixation to the correct penoscrotal location more proximally. Scrotal clefts are excised and resultant edges sutured to create a median raphe. Minor superolateral encroachment with a rugated penopubic junction is corrected by incising the ventral junction of scrotum and penile shaft skin to approximately the 4- and 8- or 3- and 9-o’clock positions and then affixing the shaft skin to the desired penoscrotal junction (Fig. 130–21). Pronounced extensions of scrotum superolaterally to the penis are moved ventrally as rotation flaps and secured to the penoscrotal junction (Fig. 130–22).

An alternative method for correction involves completely removing shaft skin from the penis, maintaining its vascular pedicle, and then subsequently moving both above the scrotum through a “buttonhole” (Kolligian et al, 2000).

Attention to vascular pedicles allows simultaneous correction of scrotal encroachment with urethroplasty, because penile and scrotal tissues derive from distinct embryologic anlage.

Assessing Surgical Outcomes

The goal of hypospadias repair is to improve function and appearance as near to normal as possible. Therefore, success requires more than straightening curvature and extending the urethra to the glans. Reports from teens and adults operated on when children emphasize that cosmetic results are as important as functional outcomes (Bracka, 1989; Mureau et al, 1995; Aho et al, 2000b). Furthermore, a glanular meatus without obstruction or fistula does not ensure the patient can void with a straight and compact stream.

Uroflowmetry

Uroflowmetry is advocated as a noninvasive means to assess neourethral function. Parameters considered include both maximum flow rate and appearance of the curve, defined as bell versus plateau shaped. Obstruction is suspected in plateau curves with maximum flow rates more than 2 standard deviations below the mean of age-matched controls (Garibay et al, 1995).

Reported results after repairs with TIP and onlay and tubularized preputial flaps indicate the majority of patients have maximum flow rates greater than the 5th percentile (Jayanthi et al, 1995; Snodgrass, 1999b; Marte et al, 2001; Hammouda et al, 2003), although many are below the 50th percentile (Jayanthi et al, 1995; Hammouda et al, 2003). Limiting the interpretation of postoperative uroflowmetry data has been reluctance to perform additional testing to confirm anatomic obstruction in patients with maximum flow rates less than the 5th percentile when they are asymptomatic or have postvoid residual urine volumes thought insignificant (<10% voided volume) (Jayanthi et al, 1995; Hammouda et al, 2003). Those who have investigated patients with maximum flow rates less than the 5th percentile report finding meatal stenosis or neourethral stricture (Garibay et al, 1995; Marte et al, 2001; Kaya et al, 2007), which suggests peak flow rates reduced to this degree should prompt calibration or cystoscopy. Postoperative plateau curves and peak flow rates between the 5th and 50th percentiles without apparent anatomic obstruction likely indicate the surgically created neourethra lacks the elasticity and smooth luminal surface of the normal urethra (Holmdahl et al, 2006; Braga et al, 2007).

Lack of universal agreement regarding normal values and minimum acceptable voided volumes limits comparisons between reported series. Significance of peak flow rates between the mean and −2 standard deviations in otherwise asymptomatic patients is unknown.

Questionnaires

Questionnaires potentially facilitate objective determination of patient perceptions regarding penile appearance and function after hypospadias repair. Various reports using questionnaires in teens and adults previously operated on with a number of different techniques provide important insights. First, cosmetic outcomes are important (Bracka, 1989; Mureau et al, 1995; Aho et al, 2000b), with patients indicating a meatus at the proper glans location is preferable to the coronal position advocated in the past (Mureau et al, 1996). In cultures that do not practice routine circumcision the appearance of the circumcised penis after hypospadias repair increases self-awareness of the prior defect (Mureau et al, 1996). Patient versus surgeon impressions of cosmetic results may vary significantly, with patients generally (Mureau et al, 1996), but not always (Weber et al, 2008), more likely to express a negative perception of their genitalia. Some factors of concern to patients, such as scars and meatal position, can be influenced by surgical technique, although others, including overall penile size, cannot. There is apparent disagreement concerning impact of the age at surgery and number of operations, because some report that older age and increasing number of operations negatively impact sexual adjustment (Mureau et al, 1995) whereas others state these factors do not necessarily relate to the patient’s genital perception (Bubanj et al, 2004).

A survey of men who underwent Koyanagi repair found 41% dissatisfied with penile appearance, but this was not significantly different from the 34% dissatisfaction reported by normal men, emphasizing the need for controls to understand the significance of responses (Moriya et al, 2006). In contrast, a cohort of teens and adults after prior two-stage preputial flap repair found 92% pleased with penile appearance, with 88% stating it was normal (Lam et al, 2005). Comparable data have not been published after other preputial flap or graft repairs described earlier or for TIP repair. However, responses by parents to questionnaires regarding the appearance of the penis after TIP repair were the same as those given by patients whose normal boys underwent elective circumcision (Snodgrass et al, 2008).

Voiding disturbances, including “spraying” (a broad stream), stream deflection, and/or postvoid dribbling are commonly reported by men after skin flap urethroplasties (Kumar and Harris, 1994; Aho et al, 2000b; Lam et al, 2005). However, one study with controls cautioned that while these voiding complaints were significantly more common in patients, half the normal men stated they had spraying, deflection, or dribbling (Moriya et al, 2006). The need to milk ejaculate has also been noted in 14% to 45% of patients (Bubanj et al, 2004; Lam et al, 2005; Moriya et al, 2006).

Persistent curvature during erection has been reported by 14% to 40% of previously operated men (Kumar and Harris, 1994; Aho et al, 2000b; Bubanj et al, 2004; Moriya et al, 2006), although normal controls had similar (Bubanj et al, 2004) or increased self-reported curvature (Moriya et al, 2006). None of these studies correlated extent of original curvature and means for straightening to these postpubertal findings.

No standardized questionnaire to determine penile appearance, micturition, or sexual function after hypospadias repair has gained widespread acceptance.

Urethroplasty Complications

Univariate analysis of factors potentially contributing to complications after TIP repair found increased likelihood with running versus interrupted two-layer subepithelial urethral plate tubularization, proximal versus distal/midshaft hypospadias, no barrier layer over the neourethra versus a dartos flap ± spongioplasty, and initial versus later experience of the operating surgeon. Of these, multivariate logistic regression analysis indicated proximal hypospadias and lack of a barrier layer as independent risk factors (El-Sherbiny et al, 2004). Comparable analyses have not been reported for other urethroplasty techniques, but generally complications are greater with more proximal hypospadias repair regardless of procedure. Periodic review by surgeons of their outcomes may prompt modifications to address specific identified problems (El-Sherbiny et al, 2004; Gapany et al, 2007) and should be considered a routine practice in hypospadias surgery.

Urethroplasty complications may occur singly or in combination, mandating thorough assessment of the neourethra when a problem is suspected. Surgical correction for the following complications is described under Reoperations.

Fistulas

Urethrocutaneous fistulas are the most common complication after hypospadias urethroplasty. Potential causes remain a matter of conjecture, and no multivariable analyses of suspected factors have been reported. For example, realization that overlapping suture lines from urethroplasty and skin closure potentially increase likelihood for fistulas dates to Duplay’s first procedure, but other factors such as larger suture size (4-0) and different suture materials (catgut, horsehair) then commonly used could also have contributed to their development.

Technical steps thought to reduce fistula risk include two-layer subepithelial closure of the neourethra and subsequent coverage with a barrier flap, usually dartos. Of these, there are more data regarding barrier layers. One RCT randomized patients with distal hypospadias undergoing TIP repair with foreskin reconstruction to receive a ventral dartos barrier flap or not, reporting a significant reduction in fistulas within the cohort assigned dartos coverage (23% vs. 8%, P = .03) (Savanelli et al, 2007). Similarly, a prospective study found addition of a dartos flap significantly reduced fistulas (26% to 3.5%, P < .01) during TIP repair in comparison to retrospectively obtained results from a second cohort of consecutive patients thought otherwise similar in age and extent of hypospadias repaired without a dartos flap (Gapany et al, 2007). Neither study provided details regarding number of layers and suturing technique (subepithelial vs. through epithelium) for urethroplasty, nor overlying glansplasty and skin closure, but stated these were similar among included patients.

Other retrospective reviews give conflicting outcomes. For example, a dartos flap significantly reduced fistulas after two-stage graft repair in one study (63% to 4.5%, P < .001), but the extent of hypospadias and whether operations were primary versus reoperative were not stated to ensure the two groups were otherwise comparable (Telfer et al, 1998). Splitting the dorsal dartos flap to create a “double-layer” barrier was found to significantly reduce fistulas versus a single-layer dartos flap (14% to 0%) in one series of TIP repair (Bakan and Yildiz, 2007) but not another (4% versus 0%, P = .5) (Kamal, 2005). The author has reported prospectively collected data indicating a 33% fistula incidence in proximal TIP urethroplasty despite using a dartos flap in every case (Snodgrass and Yucel, 2007), although a dartos flap did significantly reduce fistulas in mostly distal TIP reoperations (Nguyen and Snodgrass, 2004).

An alternative consideration to prevent fistulas is application of fibrin sealant over the neourethra. Use has been investigated in one RCT of proximal tubularized preputial flap repairs (Gopal et al, 2008) and another prospective cohort study (Ambriz-Gonzalez et al, 2007), both reporting significant decreases in fistulas with use.

Fistulas can occur at any location along the urethroplasty and can be an isolated finding or associated with other complications, including distal obstruction from meatal stenosis or neourethral stricture or turbulent urinary flow in a diverticulum. Although most often noted in the first few months after surgery, they can be overlooked in infants until evident at toilet training and also can occur years after apparently successful hypospadias repair. Fistulas occasionally close spontaneously, and there are anecdotal reports that fibrin glue can promote closure. The majority require reoperation.

Reoperations

Reoperations are required to correct various complications after hypospadias repair discussed in the preceding section or to replace the neourethra. Those for fistula, meatal stenosis or urethral stricture, diverticulum, or wound dehiscence can all be performed through a ventral midline incision, extended onto the glans wings to either side of the urethral plate in cases of glans dehiscence (Fig. 130–24). This approach provides exposure without need to re-deglove the penis, allows correction of presenting and associated complications, gives access to ventral dartos or tunica vaginalis for a barrier layer before skin closure, and facilitates cosmetic skin revision.

The algorithm in Figure 130–25 outlines options for urethroplasty reoperations. Although most techniques used for primary hypospadias urethroplasty can be adapted to reoperations, the greater complications rates that result support concerns that previously operated tissues have diminished vascularity ( Jayanthi et al, 1994).

Fistulas

Fistula repair begins with examination to exclude contributing conditions, especially distal obstruction, and distention of the urethra with methylene blue–tinted fluid to detect additional fistulas. The fistula tract is dissected to the neourethra, excised and closed with subepithelial absorbable sutures, and then covered with a ventral dartos or tunica vaginalis flap to avoid overlapping suture lines during skin closure. Surgery has been described using circular incision immediately adjacent to the fistula tract with subsequent advancement of a skin flap with its underlying dartos over the repair. The author prefers a larger midline incision though the median raphe.

Fistulas occurring at the corona potentially require alternative management. If only a thin bridge of skin connects the glans wings distally, reoperation with glansplasty is needed for fistula repair. However, if the glans wings are well approximated, coronal fistulas can be closed by dissection under the glans without need to reopen the wings and perform glansplasty (Fig. 130–26).

Multiple fistulas, or fistulas associated with meatal stenosis, neourethral stricture, or diverticulum require reoperative urethroplasty. Fistulas approximately 5 mm or greater also likely require reoperative urethroplasty for successful closure without narrowing the neourethra lumen.

Success with isolated repair of small fistulas has been reported in 76% to 96% of cases (Hayashi et al, 1998; Shankar et al, 2002; Santangelo et al, 2003). Fistulas greater than 2 mm were more likely to recur in one series (Shankar et al, 2002). Dartos flaps or full-thickness skin flaps were used routinely by some (Waterman et al, 2002; Santangelo et al, 2003) but not found to influence outcomes versus repairs without flaps by others (Hayashi et al, 1998; Shankar et al, 2002). Stents were not used for urinary diversion in one series (Santangelo et al, 2003) and not found to impact results in another (Waterman et al, 2002). These series did not systematically report the original hypospadias defect and means for repair, location and size of the fistula, sutures used for overlying skin closure, or duration of postoperative follow-up. No series reports multivariable analysis of factors possibly influencing outcomes.

Meatal Stenosis, Neourethral Stricture

Although repetitive dilation has been reported for meatal stenosis, it is unlikely to provide long-term resolution of scarring from overzealous plate tubularization or ischemia. Meatotomy can be considered if there is no evidence for BXO and the procedure can be accomplished without re-creating a hypospadias defect. Otherwise reoperation is required (see later).

Strictures discovered within 3 months of surgery have been reported more responsive to dilation or direct vision internal urethrotomy (DIVU) than those found subsequently (Scherz et al, 1988), although follow-up in successful cases of “at least 1 year” may have been insufficient to observe later failures. Overall success with DIVU for hypospadias strictures followed a minimum of 2 years is less than 25% (Duel et al, 1998; Husmann and Rathbun, 2006). Technique in prior hypospadias repair may influence response to DIVU, because one prospective study of 72 cases found urethrotomy after tubularized flaps or grafts was successful in only 4% and resulted in progression of stricture length in 56% versus success in 68% and progression in 9% after onlay or urethral plate tubularizations (Husmann and Rathbun, 2006). This report also found that adjunctive urethral dilation after DIVU did not improve outcomes over DIVU alone. Failure of DIVU should not be treated with a second DIVU but should instead prompt open urethroplasty (Hsiao et al, 2003; Husmann and Rathbun, 2006).

Neourethral strictures not amenable to, or recurrent after, DIVU are corrected using dorsal inlay grafting (see later).

Diverticulum

After excluding distal obstruction and fistulas, a midline ventral skin incision is made exposing the ballooned neourethra, which also is opened in the midline. Excess tissues are excised and the urethra is retubularized over a urinary stent and then covered with a dartos or tunica vaginalis flap. If diverticulum is encountered after onlay preputial flap repair, the flap can be excised preserving its vascular pedicle for the barrier layer, with reoperative TIP urethroplasty done using the remaining urethral plate. If obstruction is encountered distally, excised tissue from the diverticulum can be used for inlay grafting (Fig. 130–27).

Tubularized Incised Plate Reoperation

Indications for TIP reoperation include coronal fistulas with only a thin distal skin bridge approximating the glans, meatal stenosis, and dehiscence when the urethral plate is not grossly scarred. Patients with multiple fistulas or diverticulum after prior onlay flap repair can also undergo TIP reoperation with excision of the preputial flap. The author considers gross scarring of the plate or its prior excision contraindications to reoperative TIP.

Most reported patients undergoing TIP reoperation failed one prior repair, with persistent distal hypospadias. Outcomes for reoperative TIP repair are the same after previous urethral plate incision (TIP, MAGPI) versus no prior incision (flap-flap, onlay flap, glans approximation procedure) (Nguyen and Snodgrass, 2004; Ziada et al, 2006; Elicevik et al, 2007). Likelihood for postoperative fistulas is significantly reduced by dartos flap barrier layers (Nguyen and Snodgrass, 2004).

Two reports with 14 and 5 patients, respectively, describe TIP reoperation using a preserved skin strip from the meatus to glans tip as a pseudo-urethral plate when the native plate was previously removed (Luo and Lin, 1999; Hayashi et al, 2001a). Neither report mentioned postoperative neourethral stricture, suggesting dorsal skin incision potentially heals by re-epithelialization.

TIP reoperation begins with a Y-shaped ventral incision extending along each glans wing, joining on the midline shaft and then continuing to the penoscrotal junction (see Fig. 130–24). This incision provides access to ventral dartos to create a barrier flap after urethroplasty. Repair otherwise is as described earlier for primary TIP repair.

One-Stage Dorsal Inlay Graft Reoperation

When the urethral plate has been excised in prior surgery but a strip of skin without gross scarring remains in its place, midline incision of the skin strip with grafting of the resulting dorsal defect can be used for single-stage reoperative urethroplasty (Fig. 130–28). Surgical technique is the same as for TIP reoperation with graft obtained from penile or hairless groin skin or buccal mucosa (see later) quilted into place onto the corpora cavernosa using absorbable sutures at 0.5- to 1.0-cm intervals to facilitate revascularization.

Inlay grafting is also applicable to repair of neourethral strictures after hypospadias surgery but should not be used when there is possibility for BXO, because involved tissues must be excised in this condition.

Outcomes

Published reports are shown in Table 130–7. Whereas reoperative TIP repair has generally been avoided when the urethral plate is grossly scarred, Schwentner and associates (2006) reported inlay grafting successful in patients with a mean of four prior operations, including those with urethral plate scar. Their experience suggests one-stage inlay grafting is an alternative consideration to two-stage graft procedures unless there are specific indications to excise the remnant neourethra, such as BXO, hair, or persistent VC.

Two-Stage Buccal Graft Reoperation

Replacement urethroplasty is needed for gross scarring of the neourethra or when the neourethra contains BXO or extensive hair or is contracted and thereby creating recurrent penile curvature.

The first stage begins with excision of scarred or undesired tissues, which most often comprises the entire neourethra back to native urethra (Fig. 130–29). Dissection continues to the surface of the corpora cavernosa, including reestablishment of glans wings with a deep glanular cleft. Urethrostomy is created by suturing urethra to skin from the 5- to 7-o’clock position proximally.

Buccal graft is then harvested, infiltrating lines of incision with 1 : 100,000 epinephrine for hemostasis. The parotid duct is identified adjacent to the second molar and avoided when cheek mucosa is used. Dissection remains superficial to facial musculature. The graft donor site can be left open, coated with fibrin glue, or sutured closed. grafts harvested from the lip are not sutured to avoid distorting the vermillion border.

The graft should fill the ventral penile defect without tension. It is next incised proximally in the midline for 5 to 10 mm and placed along both lateral margins of the urethrostomy to minimize the likelihood both of incorporating skin follicles into the neourethra at the second stage or developing a stricture at the graft-urethrostomy junction.

Then the graft is sutured to shaft skin and glans along its perimeter with interrupted polyglactin, using subepithelial stitching in the glans to avoid suture tracks. The midline of the graft is sutured to underlying corpora cavernosa, followed by additional quilting to the corpora on either side at 5- to 10-mm intervals to minimize the opportunity for fluid collection under the graft. An RB-1 needle facilitates quilting, which is done with 6-0 polyglactin in children and 5-0 in adults.

Tie-over polypropylene sutures secure a roll of petrolatum gauze onto the graft to further reduce graft movement or fluid accumulation that might impair revascularization. The tie-over sutures and urinary catheter are removed 7 days postoperatively.

During a healing phase of 6 months the graft can be visually inspected for focal scar or contracture. Partial contracture can be managed during the planned second stage by either including adjacent shaft skin in the neourethra or by inlay buccal regrafting. Scars or more extensive contracture may necessitate excision of the involved area with regrafting as an additional step before ultimate tubularization to create the neourethra (Fig. 130–30).

At the second stage the neourethral plate is tubularized by two-layer subepithelial suture closure and then covered with a dartos or tunica vaginalis flap. Buccal tissue should not be visible at the meatus, because exposed mucosa keratinizes and sheds. A urethral catheter provides urinary diversion for approximately 14 days.

Outcomes

Although Bracka (1995) has advocated staged buccal graft reoperations, he has not published detailed outcomes. Partial or complete failure of graft take requiring an additional operation to repair the neoplate before its tubularization occurs in 10% (Andrich et al, 2003; Elmore and Snodgrass, 2004). Overall complications after urethroplasty are reported in 26% to 38% (Price et al, 2003; Elmore and Snodgrass, 2004, Snodgrass et al, 2009).

In the author’s experience, grafts using buccal tissue placed into the glans have had increased likelihood for glans dehiscence than thinner grafts of lip tissue (Snodgrass et al, 2009). Consequently, lip tissue is recommended to be used to graft the space between glans wings extending onto the shaft of the penis, with cheek tissue continuing proximally to the meatus, when needed. Lip will resurface from the glans to the penoscrotal junction in prepubertal boys if harvested, as shown in Fig. 130–31.

The author’s patients undergoing two-stage buccal graft reconstructions had a mean of 4.3 previously failed operations. Buccal graft provides a neourethral plate in this setting where penile skin is both lacking and partially devascularized. The staged approach allows inspection of the neourethral plate before its tubularization with the opportunity to revise areas of scarring or contracture. Accordingly, no neourethral strictures have occurred. Scar tissue removal from the glans and subsequent neourethral plate tubularization create a vertical meatus and normal-appearing glans (Fig. 130–32).

Others have tubularized the buccal graft or used it as an onlay urethra patch for one-stage reoperations, with resultant complications ranging from 28% to 57% (Snodgrass and Elmore, 2004), which is similar to urethroplasty outcomes after two-stage repairs. However, obstructive complications (meatal stenosis and urethral stricture) are reported in a mean of 18% of patients with one-stage (Snodgrass, 2004) versus approximately 5% of patients with two-stage operations (Elmore and Snodgrass, 2004; Snodgrass et al, 2009), most likely indicating improved graft revascularization with the two-stage approach.

Donor site morbidity was determined by systematic literature review to occur in 4% of adult patients, with no differences in overall complications between cheek versus lip harvest sites (Markiewicz et al, 2008), although most series have not systematically assessed and reported harvest site outcomes. Initial postoperative complaints include pain, numbness, and difficulty in mouth opening and ingestion. Analog pain scales indicate mid-range discomfort levels (Wood et al, 2004; Jang et al, 2005) that are similar whether donor sites are sutured closed or left open (Wood et al, 2004). Pain diminishes over the first 5 days and is resolved or mild by 1 to 6 months (Dublin and Stewart, 2004; Jang et al, 2005; Kamp et al, 2005). Lip donor sites were associated with significantly greater pain duration than cheek sites in one report (Kamp et al, 2005) but not another (Jang et al, 2005). Initial and long-term paresthesia has been found significantly increased after lip versus cheek harvest by some (Jang et al, 2005; Kamp et al, 2005) but not others (Wood et al, 2004). Impaired mouth opening usually resolves within the first month but may persist in a minority of patients for 6 months or longer (Wood et al, 2004), or patients may note continued “tightness” without restriction (Dublin and Stewart, 2004).

There are very limited data regarding morbidity associated with oral mucosa harvest sites in children. One evaluation at a mean of 6.9 years postoperatively found 19% mentioned concerns for appearance or occasional pain or numbness after lip harvest with wound suturing versus no problems after cheek harvests (Nelson et al, 2005).

Skin Flaps

Mathieu flip-flap and onlay or tubularized preputial flaps have been used for hypospadias reoperation. Technical details of the procedure including sutures preferred and use of barrier flaps were not reported in most the publications listed in Table 130–8. Most patients in these studies failed one prior attempt at hypospadias repair. As the number of failed previous surgeries increases, the likelihood that sufficient well-vascularized skin remains to create flaps for urethroplasty decreases. Jayanthi and associates (1994) stated that an unspecified number of additional patients did not undergo skin flap reoperations owing to lack of supple skin, whereas in a series of patients with a mean of 1.6 failed repairs Bar-Yosef and coworkers (2005) stated that 15% had scar that prevented reoperation with skin flaps.

Table 130–8 Reoperative Skin Flaps

image

Limitations of Hypospadias Literature

The main objective of scientific reporting is to relate experience so that other surgeons and their patients potentially can benefit from lessons learned. The following observations regarding hypospadias literature highlight recurring shortcomings that limit this communication between specialists.

Suggested Readings

Bracka A. Hypospadias repair: the two-stage alternative. Br J Urol. 1995;76(Suppl. 3):31-41.

Kaefer M, Diamond D, Hendren WH, et al. The incidence of intersexuality in children with cryptorchidism and hypospadias: stratification based on gonadal palpability and meatal position. J Urol. 1999;162:1003-1006.

Manzoni G, Bracka A, Palminteri E, Marrocco G. Hypospadias surgery: when, what and by whom? BJU Int. 2004;94:1188-1195.

Mouriquand P. Etiological aspects of hypospadias, guest editor. Dialogues Pediatr Urol, 28, 4, 2007, 1.

Nguyen MT, Snodgrass WT. Effect of urethral plate characteristics on tubularized incised plate urethroplasty. J Urol. 2004;171:1260-1262.

Snodgrass W, Bush N, Cost N. Algorithm for a comprehensive approach to hypospadias reoperation using 3 techniques. J Urol. 2009;182(6):2885-2891.

Snodgrass W, Bush N, Cost N. Tubularization of the urethral plate with and without incision for distal hypospadias repair. J Pediatr Urol. 2010;6(4):408-413.

Snodgrass WT, Koyle MA, Baskin LS, Caldamone AA. Foreskin preservation in penile surgery. J Urol. 2006;176:711-714.

Snodgrass W, Prieto J. Straightening ventral curvature while preserving the urethral plate in proximal hypospadias repair. J Urol. 2009;182(4 Suppl.):1720-1725.

Snodgrass W, Yucel S. Tubularized incised plate for mid shaft and proximal hypospadias repair. J Urol. 2007;177:698-702.

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