Using a serosal trough for fashioning a continent catheterizable stoma: technique and outcomes

Authors


Correspondence: John P. Gearhart, Johns Hopkins Hospital, Marburg 146, 600 North Wolfe Street, Baltimore, MD 21287, USA.

e-mail: jgearha2@jhmi.edu

Abstract

What's known on the subject? and What does the study add?

  • Continent urinary diversion with bladder augmentation is an established method of providing urinary continence in children with bladder exstrophy, who are not suitable candidates or have a failed bladder neck reconstruction. Sub-mucosal implantation of the tubularized catheterizable stoma (usually the appendix) into the reservoir, with backing typically provided by either the bladder musculature or colonic taenia, is safe and highly effective in these children.
  • In some cases of classic bladder exstrophy and in the majority of patients with cloacal exstrophy, the ileum is used for enterocystoplasty and therefore there is no taenia to back the implanted catheterizable channel. This study describes the steps for providing a reliable flap-valve mechanism for the continent catheterizable channel using the serosal trough technique.

Objectives

  • To evaluate the efficacy and potential complications of the serosal-trough (ST) technique for the implantation of a continent catheterizable stoma (CCS) during enterocystoplasty.
  • To describe the surgical technique and provide detailed illustrations.

Patients and Methods

  • Using an institutional review board-approved departmental database, children with bladder exstrophy, born after 1990, were selected, and patients who had undergone urinary diversion with a CCS created using the ST technique were identified.
  • Demographic and technical characteristics, as well as the eventual clinical outcomes, were retrospectively reviewed.

Results

  • A total of 135 patients with urinary diversion were identified, of whom 26 (13 males) had undergone CCS implantation using the ST technique. Patients included 14 classic exstrophies, 10 cloacal exstrophies, and two epispadias.
  • The appendix and tapered ileum were used for the creation of a CCS in 11 and 15 patients, respectively. The median (range) age at creation of a CCS was 10.7 (4.4–17.4) years. At the time of CCS creation, 21 patients underwent initial enterocystoplasty, four had repeat augmentations, and one had a CCS on a previously augmented bladder.
  • Ileum (mean length 18 cm) was used in 24/25 augmentations and was selected owing to lack of redundant sigmoid in 52% of patients and intraoperative surgeon preference in the remaining cases. In one case of cloacal exstrophy, a hindgut remnant was used.
  • In 24 (92%) cases, initial CCS resulted in complete continence of the catheterizable channel. After a median (range) of 2.5 (0.2–7.5) years' follow-up all patients were dry via intermittent catheterization. The CCS failed at postoperative months 6 and 21 and required complete revision in two cases.

Conclusions

  • Using a ST to provide a strong backing for a catheterizable channel is an excellent option when a channel must be placed in the ileum, hindgut, or in an area of augmentation where muscular backing is not available.
  • The ST technique provides a reliably catheterizable tunnel, durable continence mechanism and a good success rate when creating a CCS in combination with a urinary diversion.
Abbreviations
ST

serosal trough

CCS

continent catheterizable stoma

CIC

clean intermittent catheterization

Introduction

Enterocystoplasty combined with continent catheterizable stomas (CCSs) have provided patients with various bladder diseases a chance to be continent. Several techniques for the creation of the CCS have been proposed through the years, including intussuscepted nipples using tapered ileum, ureter, gastric segments, bladder, and the appendix [1-3]. Regardless of the choice of conduit, the flap-valve mechanism requires a tubularized channel of adequate length to be implanted sub-mucosally into the reservoir, with backing typically provided by either the bladder musculature or colonic taenia, in order to coapt as the bladder fills.

This principle, first introduced by Mitrofanoff [4], is used in wide variety of bladder diseases including spina bifida, pelvic malignancy, neuropathic bladders and the exstrophy – epispadias complex; however, in patients with complex abnormalities such as bladder or cloacal exstrophy, the native bladder may be of inadequate size and poor quality and is commonly augmented with the small bowel, thus having no teniae muscularis for appropriate flap-valve support. Keating et al. [5] were the first to describe a technique in which the conduit is implanted anteriorly into the native bladder or along the augmented portion of the bladder with a seromuscular trough created as backing.

The present study evaluates the efficacy and potential complications of enterocystoplasty and CCS implantation using the serosal-trough (ST) technique in a select population of patients with exstrophy – epispadias complex at our institution. Long-term follow-up and detailed description and illustrations of the procedure are also provided.

Patients and Methods

Using an institutional review board-approved departmental database, 504 children with a diagnosis of bladder exstrophy or epispadias, who were evaluated between 1990 and 2010 at our institution were considered. Patients with available medical records were evaluated and those with continent urinary diversions were included. Inclusion criteria included enterocystoplasty using the small bowel and implantation of the CCS, using the ST technique, into the bowel patch that has been used for augmentation and not into the native bladder. Twenty-six patients met the inclusion criteria and were included in the present study.

Each patient's medical records were reviewed for demographics, technical characteristics of the surgery and clinical outcomes.

Surgical Technique

The procedure is typically started by freeing up the appendix from the caecum and making sure it has enough mesentry length to reach the augmented bladder. It should also have sufficient width to accept a 12–14 F catheter. An adequate length of bowel is then taken down, opened on the antimesenteric side, and used for the augmentation of the bladder. A well-vascularized segment of ileum with adequate mesentry is used for enterocystoplasty in the present series. The ST is created on the anterior aspect of the neobladder. Two parallel longitudinal incisions are made lateral to the ultimate course of the conduit, incising the serosa only. This exposes the intact mucosa underneath (Fig. 1). Tacking sutures help to fan out the serosal layer and define the limits of the trough. The most proximal end of the conduit needs to be tacked to the augmentation to prevent intussusception in the future. The trough should be of adequate length (>10 cm) to receive and cover the new conduit properly. The incisions are joined caudally and the tubularized conduit is placed on the newly created trough. To complete the wrap of the trough, 3/0 polypropylene sutures are used, covering the new CCS with a length : width ratio of >5 : 1 (Fig. 2). One should avoid tension when tying the sutures or placing the incisions too close, otherwise over-compression of the CCS can compromise the function of the conduit. At the same time, it should provide adequate coverage and depression of the CCS.

Figure 1.

Two parallel longitudinal incisions only on the serosa are made to expose the underlying mucosa (A). The two incisions are caudally joined forming a U-shaped incision. Tacking sutures help to fan out the serosal layer and define the limits of the trough (B,C,D).

Figure 2.

The tubularized conduit is placed on the newly created trough (E,F). Tacking sutures are used to wrap the trough, covering the new CCS with a length : width ratio of >5 : 1. Pulling the sutures too hard may cause over-compression of the catheterizable stoma and compromise the function of the conduit (G).

With a catheter in place, the end-to-end anastomosis of the conduit to the reservoir is secured and the lateral edges of the incisions of the trough are approximated over the conduit. After closing the fascia, the bladder augment is tacked to the anterior abdominal wall and the stoma is brought out of the fascia at a site as close to the bladder as possible to provide the shortest intraperitoneal length possible. It is imperative to make the stoma as straight as possible to ensure easy catheterization and minimal trauma. After creating a v-shaped skin flap, the stoma is matured in the midline as a neo-umbilicus (Fig. 3). Before finishing the procedure, it is necessary to ensure the stoma catheterizes well. If it is not easy in the anaesthetized patient, it will not be easy when the patient is awake.

Figure 3.

The catheterizable stoma is attached to the reservoir with an end-to-end anastomosis (H) and then the stoma is matured on the abdominal wall (I).

Results

The present cohort comprised 135 patients with urinary diversion, of whom 26 (13 females) had a CCS implantation using the ST technique. Cases included 14 classic bladder exstrophies, six cloacal exstrophies, four cloacal exstrophy variants and two epispadias. Only six patients had their initial bladder closure performed at the authors' institution and the remaining 20 were referrals. Nine patients (35%) had a history of initial closure failure that required reclosure (Table 1). The bladder neck was transected in all patients and the CCS was created using the appendix in 11 patients and the Monti tapered ileum in 15 patients. The CCSs were implanted into the augmented bladder using the ST technique.

Table 1. Characteristics of 26 patients who underwent CCS creation using the ST technique
Characteristic 
Sex, n (%) 
Female13 (50)
Male13 (50)
Diagnosis, n (%) 
Classic bladder exstrophy14 (54)
Cloacal exstrophy6 (23)
Epispadias4 (15)
Cloacal exstrophy variant2 (8)
Bladder exstrophy variant0 (0)
Primary closure failure17 (65)
Stoma type, n (%) 
Appendix11 (42)
Monti15 (58)
Bladder augmentation, n (%)25 (96)
Median (range) continent urinary diversion age, years10.7 (4–17)
Median (range) capacity before continent urinary diversion, mL116 (25–820)
Median (range) follow-up, years)2.3 (0.2–8)

The median (range) age at creation of CCS was 10.7 (4.4–17.4) years. At the time of CCS creation, 21 patients underwent initial enterocystoplasty, four required a repeat augmentation, and one had an adequate previous augmentation and needed only a new CCS. Incontinence and small bladder capacity were the main indications for augmentation (n = 22) followed by previous CCS failures (n = 3), and severe stricture after epispadias repair and a small bladder (n = 1). Ileum (mean length 18 cm) was used in 24/25 augmentations; the ileum was selected because of lack of redundant sigmoid in 52% of cases and intraoperative surgeon preference and easy access in the remaining cases. In one case of cloacal exstrophy, a hindgut remnant was used for enterocystoplasty.

In 24 of 26 patients (92%), initial CCS resulted in complete continence of the catheterizable channel. After a median (range) 2.5 (0.2–7.5) years' follow-up all 24 patients were dry via intermittent catheterization. In two cases, the CCS failed at 6 and 21 months after the initial procedure and required revision of the stoma. Minor complications included skin-level stoma stenosis (n = 5) requiring revision at a median (range) of 18 (4–32) months after the initial procedure (Table 2).

Table 2. Complications associated with CCS using the ST technique in 26 patients
Variablen (%)
Bladder 
No complications20 (77)
Stone5 (19)
Infection0 (0)
Perforation0 (0)
Stoma 
No complication16 (61)
Leakage3 (11)
Stenosis5 (19)
Difficulties in catheterizing2 (8)
Stoma failure2 (7.7)

Discussion

Providing urinary continence is a feasible goal in patients with complex urological malformations, thanks to novel reconstructive techniques that have been developed in the past several decades. Mitrofanoff [4] has revolutionized the way CCSs have been created since 1980 and uses the principle of providing a unidirectional, non-refluxing flap-valve mechanism in order to empty the bladder using a catheter. What is widely accepted as the ‘Mitrofanoff principle’ is that any supple tube implanted sub-mucosally with sufficient muscle backing acts as a flap valve and results in a continent catheterizable channel.

The appendix is the preferable source for creating the CCS, but it may not be readily available in many cases, so a reconfigured ileal channel (Monti procedure) has become a popular alternative owing to the reliability and quality of the small bowel [2]. To achieve continence, the CCS requires a patent tube, straight path, and short intra-abdominal segment re-implanted in an anti-refluxing manner. Detrusor muscle provides an ideal continence valve when a CCS is re-implanted sub-mucosally into the native bladder, but in patients who require bladder augmentation, such as many patients with classic exstrophies and the majority of patients with cloacal exstrophies, the native bladder is usually insufficient or inappropriate for CCS implantation. When this is the case, implanting beneath the tenea is an option when the colon is being used for augmentation. As shown in the present study, the ST technique can be used successfully in cases where colon segment is not available for augmentation or is not the desired segment, and the conduit must be implanted into a segment of small intestine that lacks tenea.

Historically, the major complications associated with continent urinary diversion include electrolyte imbalances, bladder stones and stoma complications [6]. It is known that ineffective bladder emptying leads to urine stasis, increased bacterial load, and propensity to develop UTIs. According to previous reports, the rate of UTIs after bladder augmentation is 19–63% and is significantly correlated with catheterization compliance [6, 7]. Although bacterial colonization is an inevitable complication of percutaneous catheterization, only two (8%) patients in the present series had recurrent infections requiring systemic antibiotic treatment. Interestingly, both patients had their CCS implanted in the posterior aspect of the neobladder. This contrasts with a previous observation by Berkowitz et al. [8] where they showed that anteriorly placed CCSs are more prone to infection and hypothesized that ineffective bladder emptying can be contributory. In the author's experience, once the child and the parents were adherent to clean intermittent catheterization (CIC), the rate of symptomatic infection was not increased using either technique.

The creation of a CCS using ST gradually failed in two patients at 6 and 21 months after the operation, resulting in an 8% failure rate. The reasons for failure in the first case were a remarkable paucity of abdominal skin accompanied by severe short gut syndrome and inadequate lubrication during CIC, which caused a CCS failure, despite a healthy stoma segment. The patient still has some mild leakage from the stoma and is not reliably adherent to CIC. The second case is a patient with classic exstrophy who was dry for 21 months after the operation when he started experiencing leakage from the stoma. The patient was given a new Monti stoma re-implanted into the previously augmented bladder using the ST technique. Currently, 36 months after the operation, he is dry and performs CIC with no difficulty.

Different CCS creation techniques are associated with a wide range of success rates in the literature [9]. The Monti technique is known to be associated with significant urinary leakage and stoma stenosis in up to 32% of cases. Some authors hypothesize that eccentric dilatation of the tube and mucosal pleating make catheterization difficult in up to 60% of patients [10]. As Monti stomas have a drier inner surface than those from the appendix [11], they require more lubrication and this might have contributed to the two failed cases in the present series.

The present study extends a previously described technique, with emphasis on an illustrated surgical procedure and surgical outcome [5]. This technique has been effectively used for almost 20 years by the authors adhering to the same key principles in a rare, and arguably the most complex, congenital malformation in paediatric urology. The present study represents the largest experience reported on this subject but is limited by its retrospective nature and the inherent selection bias of patients with bladder exstrophy.

In conclustion, the use of a ST to provide a strong backing for a catheterizable channel is an excellent option when a channel must be placed in the ileum, hindgut, or in an area of augmentation where muscular backing is not available. This technique provides an excellent tunnel, durable continence mechanism, and a good success rate when creating a CCS in combination with a urinary diversion.

Conflict of Interest

None declared.

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