Multiple failed closure of bladder in children with vesical exstrophy: Safety and efficacy of temporary ileal patch augmentation in assisting bladder closure.

OBJECTIVE: The surgical approach to small bladder template in exstrophy bladder is difficult. Previously, many of these children underwent ureterosigmoidostomy and in recent times, the trend is to do a delayed primary closure. We have used ileal patch as a temporary cover for these small bladders with a view to encourage bladder growth and early results are encouraging.
MATERIALS AND METHODS: In five of the 45 children with bladder exstrophy managed by radical soft-tissue mobilization over 10 years, primary bladder closure was not possible due to repeated failed closures. A detubularized ileum was used to patch the bladder initially and after 4 months the patch was excised and bladder closure with sphincter repair was done in second stage.
RESULTS: In five children (three girls and two boys) the mean age at initial bladder closure was 14 months and mean age at ileal patch was 22 months. In four patients, the bladder grew facilitating closure and in one patient it failed. There were no complications with the use of gut in patch.
CONCLUSION: A temporary ileal patch seems promising in managing failed bladder closure in exstrophy patients. Long-term studies are needed before such a technique can be used in all patients with failed primary bladder closures.

INTRODUCTION

Surgical care of bladder exstrophy starts immediately after birth and includes various staged procedures as well as one stage repair. Essentially with any procedure, the aim is to close the opened out bladder to make it a reservoir for urine storage and provide sufficient muscular outlet resistance to provide a voluntary continence mechanism. Occasionally, some bladders cannot be closed primarily due to small sized bladder template or repeated failed closures or occasionally due to late presentation. These bladders are thick and fibrosed with superimposed cystitis cystica making primary closure difficult and occasionally impossible. Under normal circumstances, it has been shown that such bladders grow in size with time and majority undergo a delayed primary closure, which usually succeeds.[1] The disadvantage of this technique is that the bladder may grow, but inflammation and fibrosis continues unabated and leaking open bladder during waiting period is challenging to parents. An ileal patch has been used as a temporary cover over small bladders in five patients and the results are encouraging. At the end of 4 months, the bladder could be closed after excising the bowel in four patients. These were the patients in whom repeated attempts at bladder closure had failed and further attempts at closure by routine were not possible.

MATERIALS AND METHODS

Forty-five children with exstrophy bladder were treated by two staged radical soft-tissue mobilization procedure over a period of 10 years from May 2001 to June 2010 in a tertiary care referral center. Five patients were included for temporary ileal patch cover who had repeated failures at primary bladder closure. In one patient, the bladder size was less than 3 cm at birth [Figure 1] and dehisced twice after closure. The remaining four patients were late referrals from other hospitals after multiple failures at bladder closure, so the data on the initial bladder size was not available. There were three girls and two boys with a mean age at initial bladder closure being 14 months and 5 days (2 days to 36 months). In one patient, the bladder was closed on day 2 of life and the rest of the patients had delayed initial bladder closure. Two patients had undergone osteotomy during initial bladder closure (done elsewhere). The mean age at ileal patch was 22 months (8-48 months). Mean age at 2nd stage was 28 months and 3 days. At the time of ileal patch closure, the average size of the bladder was less than 3 cm and could not be invaginated under general anesthesia [Figure 2]. All patients who presented with small bladders at birth before any attempt at primary closure were excluded.

Figure 1

Very small bladder plate in a neonate. This child had complete dehiscence after two attempts at primary closure. A temporary ileal patch was successful

Figure 2

Repeated attempts at bladder closure sometimes render them so small and fibrotic that primary closure is impossible. All the five patients in our series had such bladder, where primary closure was not possible

Technique of ileal patch

Consent form was obtained for primary closure as well as application of patch before surgery. All children were operated under general anesthesia with caudal anesthetic block. Preoperatively standard preparation as for other bladder closures was used. Perioperative antibiotics were given and continued until the ureteral catheters was removed. No specific bowel preparation or prolonged fasting was used for the procedure. The ureters are intubated with 5Fr. Infant feeding tubes and anchored. After mobilizing the bladder from skin and rectus sheath, the peritoneum was deliberately opened just below the umbilicus [Figure 3a]. An appropriate sized ileal segment with intact mesentery away from the ileocecal junction is carefully isolated [Figure 3b], detubularized by opening near the mesenteric border, cleaned with Betadine solution and was anastomosed full thickness to the mobilized bladder [Figure 3c], the lower limit being just above the verumontanum. The lower end at the bladder neck was left open through which the ureteral catheters exited. Rectus muscle was closed in mid-line by mobilizing the medial margins of anterior rectus sheath. Skin closure was completed [Figure 3d].

Figure 3a

Technique of ileal patch. Peritoneum is opened above bladder and terminal ileal loop is isolated

Figure 3b

Window is made in mesentery to carefully preserve the vascular arcade

Figure 3c

Detubularized ileal patch is sutured to mobilized bladder. Note: Ureteral catheters exiting at lower end

Figure 3d

Completed abdominal closure

Postoperatively the baby was nursed in trendelenburg position with immobilization of lower limbs, by strapping them together with pad and bandage for 48-72 h. This was to prevent tension on the mesentery. The baby was fasted until the bowel function returned. The ureteral catheters were removed after 5-7 days. The 2nd stage was done after 4-6 months preceded by a cystoscopy. Before closure, all children were evaluated for renal function (Blood urea and serum creatinine, electrolyte disturbance, urine culture and renal tract ultrasound). In the 2nd stage, the patch was excised along with margin of the bladder mucosa and bladder closure and sphincter repair was done as a single stage.

RESULTS [TABLE 1]

None of the patients had major acid base or electrolyte disturbance and urine was sterile before the 2nd stage. Ultrasound was normal in all patients before 2nd stage. At the end of 4 months in four patients, cystoscopy showed that the bladder had grown in size, with virtual absence of cystitis cystica and the bowel patch had become a diverticulum. This patch was excised. Bladder closure with epispadias repair and sphincter/levator approximation could be done as a single procedure and was successful in all four patients. In one patient, the bladder remained the same at 4 months and repeats cystoscopy twice after 3 months and 6 months showed small bladder and was unsuitable for 2nd stage repair. He was counseled for a second attempt of patch closure, but parents opted for a permanent augmentation.

The follow-up after completion of sphincter repair was similar to the follow-up being used for conventionally managed children with renal tract ultrasound every 6 months, micturating cystourethrogram if needed, and assessment of continence at regular intervals. Functional assessment for continence was done when child reached 5 years of age. There were no complications related to use of bowel in these patients. No significant fluid and electrolyte disturbance were seen in any patient during follow-up. Minor complications were seen in four patients. Superficial wound dehiscence occurred in two patients after 2nd stage, which healed with conservative management. One boy had a penopubic fistula which needed repair and one girl had vulval scarring which was repaired.

DISCUSSION

At birth, the exstrophic bladder is smooth, pliable, and most can be closed primarily, though the size of bladder template is variable. Small bladders eventually grow after closure.[2] In a child with small bladder plate it can be closed primarily with the hope that it grows with age and the 2nd stage can be done later. The other option is to delay the closure for 6 months to 1 year and studies have shown that the bladder grows in size making closure possible.[3] In a series of 19 patients with a small bladder managed by delayed closure over 6 months, Dodson et al.[3] have reported that in nine patients, functional repair was possible (47%) and achieved continence; delay in closure did not decrease the need for augmentation, but achievement of functional continence was unaffected. However, the same may not be possible in patients in multiple redo closures and failed closures. In such cases, primary closure of the bladder is impossible as multiple attempts at closure may occasionally render it fibrotic and thickened.

As our institute being a major referral center for exstrophy management, over the past 10 years we came across five such children with very small fibrotic bladders who had multiple failed closures. Sparing a permanent augmentation we innovated a way to close these bladders by applying a patch of ileum temporarily. After 4 months, the bladder had grown in size, became more pliable and cystitis cystica had resolved [Figure 1]. In the 2nd stage the bowel segment was excised, the bladder could be closed and the radical soft-tissue mobilization with sphincter repair and levatorplasty was completed. One patient showed no sign of bladder growth at 6 months after ileal patch.

The mechanism of ileal patch and bladder growth could be explained partly on the basis of changes seen in permanently augmented bladders. With an opened out bladder (as in unclosed exstrophy) there is no urine recycling and repeated inflammation due to exposure renders it fibrotic. With a patch, the urine recycling is maintained which is an impetus to bladder growth. Also with a closed bladder, inflammation and fibrosis is avoided. The bowel doesn’t grow as much as bladder because of detubularization. It has been shown that ileal mucosal atrophy occurs due to prolonged exposure to urine[45] and the vascularity to ileum may reduce. The net effect is bladder grows, becomes pliable and the bowel becomes a diverticulum [Figure 4].

Principles of ileal patch closure. The thickened trabeculated small sized bladder has grown in size, folded on itself and at the end of 4 months, the ileal patch has become a diverticulum. Note the communication between the two segments has become a small fibrotic ring and this was consistently seen in four of the five patients who underwent patch closure

Individuals who have undergone augmentation cystoplasty and ileal conduit diversion are at increased risk for the late development of cancer with overall incidence of 1.5%. Adenocarcinomas develop at or near the enterourothelial junction.[6] While excising the bowel before bladder closure, we have ensured that sufficient margin of enterourothelial junction is also excised. We do not have data on whether a short period of exposure of the bladder to ileum, risks malignancy. A temporary ileal patch is a major procedure and is only used as a desperate measure to salvage a scarred fibrotic exstrophy bladder. Presently we would not recommend its use in a neonate with small exstrophy bladder without any attempts at primary closure or delayed primary closure.

CONCLUSION

Native bladder is the best reservoir for urine storage. Small fibrotic bladder with repeated failures to achieve a primary closure should not be excised. A temporary bowel patch makes bladder closure possible by preventing further fibrosis and allowing bladder growth. Until further refinements in tissue engineering techniques of bladder regeneration are successful, a temporary bowel patch should be a viable option in managing such patients.

Table 1

The characteristics of patients undergone ileal patch