Antegrade Continence Enemas

Fecal incontinence may be more socially debilitating to patients than urinary incontinence. In a sense, it has been easier to work surgically on urinary incontinence because urologists and their patients have intermittent catheterization to reliably empty. Unfortunately, that has not been the case with constipation and fecal incontinence, particularly among patients with neurogenic dysfunction. Malone and colleagues (1990) have described use of the appendix for antegrade continence enemas (i.e., the MACE procedure) to control constipation and achieve fecal continence in patients with complex gastrointestinal disorders refractory to conservative management. These enemas, usually performed once a day, provide a thorough cleansing in a short time. Patients, particularly those with neurogenic dysfunction, often will not stool again until their next enema (Curry et al, 1999). Cecostomy tubes, cecostomy buttons, and tapered intestinal segments tunneled into the cecum have been used for the enemas when the appendix is not suitable or is unavailable (Stanton et al, 2002; Kim et al, 2006a; Yagmurlu et al, 2006; Biyani et al, 2007b; Lorenzo et al, 2007b; Heshmat et al, 2008). Antegrade continence enemas as originally described by Malone have been used extensively in the neurogenic population (Koyle et al, 1995; Curry et al, 1999; Kim et al, 2006a; Vande Velde et al, 2007; Bani-Hani et al, 2008b; Sinha et al, 2008b). Enemas can be performed using saline, but tap water has been found to be equally suitable (Hyde et al, 2008). Metabolic derangements are unusual, although water treated in a softener should be avoided because it can cause hypernatremia (Yerkes et al, 2000).

Average irrigating volumes in most series have approached 650 mL but occasionally reach 1000 mL. The transit time for the enema after insertion varies among patients but averages 25 minutes and ranges from 15 minutes to an hour (Hyde et al, 2000; Hinds et al, 2004; Bani-Hani et al, 2008b). Smaller volumes and less transit time may be required for left colon antegrade enemas (Churchill et al, 2003). Additives to the irrigant may decrease the transit time in some patients (Kajbafzadeh and Chubak, 2000; Bani-Hani et al, 2008b). The enemas are begun daily as soon as bowel function returns after reconstructive surgery. The initial volume used is low and typically increased every 2 or 3 days until adequate decompression is achieved. Fecal continence until the next enema has been consistent for most patients with neurogenic dysfunction and ranges from 67% to above 90% (Hensle et al, 1998; Herndon et al, 2004b; Kim et al, 2006a; Vande Velde et al, 2007; Bani-Hani et al, 2008b; Sinha et al, 2008b). Hensle and colleagues (1998) noted occasional soilage requiring a pad in one fourth of their patients performing the enemas routinely. The majority of patients can perform the enemas independently. Almost universally, the patients and families have continued to perform the enemas on a regular basis in these series, which is good evidence that they find the results to be worth any time and effort involved (Yerkes et al, 2003; Herndon et al, 2004b). Rare patients may have severe colonic spasms with flushing that preclude use (Bau et al, 2000). They occasionally respond better to multiple flushings with smaller volumes. The most common complication, as with use of the appendix as a catheterizable stoma elsewhere, has been stomal stenosis, although stenosis may not occur as commonly as when the appendix is moved to the bladder (Kaefer et al, 2000). Some children require catheterization of the appendix twice a day to avoid contracture or a cicatrix at the skin level. Mickelson and associates (2009) have described the use of an L stent with or without steroid cream placed nightly to maintain patency. Fecal and irrigant incontinence can occur and is socially unacceptable. Reassessment of irrigating technique is important along with radiographic confirmation of irrigant transit through the colon. Endoscopic injection of a bulking agent at the junction of the catheterizable channel and the cecum can be tried (Koivusalo et al, 2006). Formal open revision and reinforcement of the catheterizable channel may be required. Perforation of the appendix has been noted with catheterization, as has false passage parallel to the appendix. Subsequent intraperitoneal injection of the enema fluid has resulted in peritonitis. Such patients require antibiotics and close observation. They do not routinely require reoperation (Brock, 2000). Kokoska and associates (2004) reported two cases of cecal volvulus among 164 patients using these enemas.

The appendix can be used easily in situ (Fig. 129–22). In review of a large experience, Bani-Hani and colleagues (2008a) have noted fewer complications after in-situ use of the appendix than with other techniques. Windows in the mesoappendix may be made and permanent Lembert sutures used to approximate the cecal wall in each window. This effectively wraps the cecum around the base of the appendix to prevent spillage. Alternatively, one taenia leading to the appendix may be incised longitudinally and reapproximated in the windows of the mesoappendix. Others have made no attempt to construct a continence mechanism at the appendicocecal junction, particularly surgeons performing antegrade continence enemas laparoscopically (Cadeddu and Docimo, 1999; Casale et al, 2004; Nanigian et al, 2008). A left colonic catheterizable channel has been advocated especially when the appendix is not available. The results are similar to an appendicocecostomy, with continence reported to be 74% to 94% and stomal stenosis at a rate of 26% (Kim et al, 2006b; Sinha et al, 2008a). Most MACE procedures are performed by urologists at the time of a major reconstructive procedure involving the bladder (Casale et al, 2006). Their long experience with construction of continent catheterizable stomas for the urinary bladder has taught them the principles to achieve a good result, but about 15% of patients will require some revisional surgery (Bani-Hani et al, 2008a). The authors’ preference is to provide some continence mechanism at the base of the appendix in this setting to avoid any spillage (Donohoe et al, 2004).

Figure 129–22 The appendix used in situ for antegrade continence enema or urinary continent catheterizable stoma. The appendix and its mesentery are mobilized without detachment from the cecum. Windows are carefully made in the mesentery between vessels to the proximal appendix. The taeniae from either side of the cecum are approximated in those windows with permanent sutures to ensure continence of the stoma. The distal end of the appendix is brought to the abdominal wall for catheterization.

Urinary Refunctionalization

The clinical need for urinary refunctionalization has changed dramatically during the past several decades. Before the acceptance of CIC (Lapides et al, 1976), many children were not candidates for complex reconstructive procedures because of an inability to empty afterward. Many were initially treated with permanent urinary diversions with use of an intestinal segment with high expectations. Over time, it became clear that such diversions had significant complications, including infection, stones, and nephropathy (Smith, 1972; Richie et al, 1974; Shapiro et al, 1975; Middleton and Hendren, 1976; Pitts and Muecke, 1979). With the recognition of those complications and the routine use of CIC, urinary refunctionalization became a relatively common procedure for the reconstructive surgeon (Hendren, 1974, 1987, 1990; Perlmutter, 1980). Fewer patients now require diversion. Better anesthetic and perioperative surgical care has allowed safe definitive repair of primary problems in younger infants. The occasional diversion presently done in extreme cases is usually temporary rather than a permanent one using bowel. Consequently, urinary refunctionalization now is infrequent and typically involves closure of some urinary stoma rather than takedown of an intestinal segment.

Permanent diversions in children are now typically confined to cancer patients. When their outcome is good, they may then be candidates for urinary refunctionalization and conversion to continent urinary diversion. The Boston group has favored initial temporary diversion with a transverse colon conduit to avoid irradiated bowel when cystectomy is required. Once cure is ensured, the conduit can be converted to a continent reservoir by augmenting the colonic segment with stomach to provide an adequate reservoir and by providing a continent catheterizable efferent limb (Duel et al, 1996).

The key to urinary refunctionalization is understanding the original pathologic process that led to diversion. This may be relatively easy if the surgeon involved has cared for the patient throughout his or her course. If the original diversion was done by someone else years previously, such understanding may be difficult and require thorough investigation. Accurate understanding of the underlying disease may be made more difficult because of defunctionalization of the remaining urinary tract. It is important to review the patient’s original history and studies to understand the pathophysiologic changes before any intervention. For example, failure of the urinary bladder in a patient with neurogenic dysfunction to respond adequately to anticholinergic medication and intermittent catheterization before vesicostomy diversion might well predict that it will not do so after vesicostomy closure. Special nuances in the current evaluation may also be necessary. Urodynamic evaluation of a bladder diverted for several years with a vesicostomy will virtually always show a small capacity. A repeated study after several days of bladder cycling or occlusion of the vesicostomy may be more predictive of bladder function. The bladder may respond to bladder cycling quickly (Bauer et al, 1986; McGuire, 1996). Temporary occlusion of a vesicostomy with a gastrostomy button may be informative (de Badiola et al, 1995). Occlusion of the vesicostomy during urodynamics may be necessary to achieve good bladder filling and to accurately define the adequacy of outflow resistance. Such parameters must be evaluated before urinary refunctionalization and may have changed since the time of diversion, particularly in patients with neurogenic dysfunction. Antegrade perfusion studies may be helpful and necessary in evaluation of the upper tract previously diverted by ureterostomy or pyelostomy.

Correction of Original and New Pathologic Processes

It is essential that all pathophysiologic change is appreciated, whether it is original or new. Failure to do so can result in recurrent clinical problems for the patient (i.e., renal insufficiency, hydronephrosis, infection, and incontinence) in the presence of a technically perfect operation. Once the reconstructive surgeon understands those problems the reconstructive options available for urinary refunctionalization should be assessed on an individual basis. Considerations include the length, dilation, and scarring of the ureters; the volume, compliance, and fibrosis of the native bladder; and the function of the outlet in terms of resistance for continence and synergistic relaxation for emptying. More global problems, such as renal insufficiency and neurogenic dysfunction, may influence the choices of technique as well. In patients with an existing permanent diversion involving an intestinal segment, the quality, length, and volume of that segment should be considered to determine how it might best be used in reconstruction. An existing ileal conduit might be used as an ileal ureter, as a segment for bladder augmentation, or for tapering as a continent stoma, depending on the needs of the patient.

For examples that illustrate the potentially complex nature of many urinary refunctionalization cases, the reader is referred to Dr. Hendren’s chapter on undiversion in prior editions of this text (Hendren, 1998). No one has more experience, and his cases demonstrate the total command of all surgical alternatives that is required to manage these patients well. The illustrated cases there are typical of the types of patients that historically underwent undiversion.

Results

Hendren (1998) reported a 26-year experience with urinary refunctionalization in 216 patients. Two thirds of the patients had permanent diversions, often of long duration. He noted that many of the patients had impaired renal function, either from their underlying problems or as morbidity related to the diversion. More than 10% of the patients had already required renal transplantation after undiversion, and even more were progressing toward it. With successful relief of obstruction, prevention of reflux, and provision of a compliant bladder, Hendren noted that urinary refunctionalization prolonged the time to renal failure in some patients and may have avoided it entirely in others. Urinary refunctionalization may protect renal function rather than contribute to any decline if it is properly selected and performed.

In Hendren’s series, management of the bladder was relatively straightforward and effective with bladder augmentation as necessary. Inadequate outflow resistance was usually treated with Young-Dees-Leadbetter bladder neck repair. Most complications were related to the ureters: 23 patients required reoperation for persistent reflux; 10 did so for partial obstruction of the ureter. Those reoperation rates are indicative of the difficulty one faces in dealing with short, dilated, and scarred ureters that may be present after urinary diversion (Hendren, 1998). Others have had similar good success (Gonzalez et al, 1986; Mitchell and Rink, 1987) with urinary refunctionalization.

The success of many of the techniques necessary for urinary refunctionalization should be similar to the success of those done in primary reconstruction. In other words, the good results of ileocystoplasty or appendicovesicostomy should be equivalent whether they are done as part of a urinary refunctionalization or not. As noted in Hendren’s cases and series, many problems may be present and multiple techniques might be required for a given patient. The key to achieving a good result in urinary refunctionalization is to understand all of the patient’s problems and to correct each. The most difficult measure of complex urinary refunctionalization, and the one most prone to complication, relates to the short, dilated, and chronically scarred ureter that may be the residual of the original problem or secondary to prior surgery including diversion.

In occasional cases of urinary undiversion, conversion to a continent urinary reservoir is appropriate. This is true of cases in which the native bladder is congenitally absent, removed, or heavily irradiated. In those rare cases, the volume and quality of the patient’s native tissue may be so poor that inclusion in the reconstruction is not warranted. In the majority of cases of urinary refunctionalization, reconstruction of the native urinary tract is preferable to continent diversion. Such reconstruction can minimize morbidity to the patient by utilizing more tissue line by urothelium.

Key Points: Urinary Refunctionalization

• Most urinary refunctionalization procedures now involve takedown of a urinary stoma rather than an intestinal diversion.

• It is key to understand the patient’s underlying pathophysiologic process as well as any problems related to diversion.

• Chronically scarred and shortened ureters may be a challenge in these patients.

Summary

Every effort should be made to treat pediatric bladder dysfunction, no matter what the etiology, early and aggressively to minimize the number of patients requiring reconstructive surgery for bladder and sphincter dysfunction. Some such surgery will still be necessary, and the patients must be carefully evaluated so that all problems are identified and addressed. The surgeon should then be flexible and prepared to use the bowel segments and techniques that best fit each patient. Whereas a given surgeon’s result with any technique may improve with experience and confidence, each patient’s unique problems and anatomy may make some choices better than others. Forcing one procedure to fit every patient should be avoided.

Preoperative evaluation should identify upper tract obstruction or vesicoureteral reflux. Such problems should be corrected at the time of surgery, although low-grade secondary reflux will usually resolve spontaneously with correction of bladder dysfunction. It is imperative to provide the patient with an adequate bladder or reservoir, one capable of holding at low pressure a urinary volume that will be produced between voidings or catheterizations. This can be accomplished by either augmentation or construction of a continent reservoir with use of any gastrointestinal segment. Each has its own set of advantages and disadvantages that should be considered. If adequate outflow resistance is lacking, it should be created at the bladder neck to prevent incontinence. Any patient undergoing reconstructive surgery for bladder or sphincter dysfunction must be prepared to perform and be capable of performing intermittent catheterization on a reliable basis; most will require it routinely. This is particularly true of those patients with neurogenic dysfunction.

As much of the patient’s native urinary tract as possible should be preserved in pediatric urologic reconstruction. The urothelial lining avoids much of the morbidity associated with intestinal segments. If necessary, however, virtually any portion of the lower urinary tract may be reconstructed or replaced with intestine. Unfortunately, occasional complications do occur when intestinal segments are used in that manner. They are not perfect physiologic substitutes. Patients after reconstruction require a lifetime of follow-up, and that observation should include careful evaluation of their true quality of life. The most important factor in avoiding problems with such complex pediatric patients is the motivation of the patient and family to achieve a successful outcome. Assessment of that commitment is critical.