The impact of repeated bladder surgery on successful bladder neck closure in classic bladder exstrophy: The role of mucosal violations.

INTRODUCTION: Restoration of genitourinary anatomy with functional urinary continence is the reconstruction aim is the exstrophy-epispadias complex (EEC). In patients who do not achieve urinary continence or those who are not a candidate for bladder neck reconstruction (BNR), bladder neck closure (BNC) is considered. Interposing layers including human acellular dermis (HAD) and pedicled adipose tissue are routinely placed between the transected bladder neck and distal urethral stump to reinforce the BNC and minimize failure due to fistula development from the bladder.

OBJECTIVE: The aim of this study was to review classic bladder exstrophy (CBE) patients who underwent BNC to identify predictors of BNC failure. Specifically, we hypothesize that increased operations on the bladder urothelium leads to a higher rate of urinary fistula.

STUDY DESIGN: CBE patients who underwent BNC were reviewed for predictors of failed BNC which was defined as bladder fistula development. Predictors included prior osteotomy, interposing tissue layer use and number of previous bladder mucosal violations (MV). A MV was defined as a procedure when the bladder mucosa was opened or closed for: exstrophy closure(s), BNR, augmentation cystoplasty or ureteral re-implantation. Predictors were evaluated using multivariate logistic regression.

RESULTS: A total of 192 patients underwent BNC of which 23 failed. Patients were more likely to develop a fistula with a wider pubic diastasis at time of primary exstrophy closure (4.4 vs 4.0 cm, p=0.0016), have failed exstrophy closure (p=0.0084), or have 3 or more MVs before BNC (p=0.0002). Kaplan-Meier analysis of fistula-free survival after BNC, demonstrated an increased fistula rate with additional MVs (p=0.0004, Figure 1). MVs remained significant on multivariate logistic regression analysis with a per-violation odds ratio of 5.1 (p<0.0001). Of the 23 failed BNC's, 16 were surgically closed including 9 using a pedicled rectus abdominis muscle flap which was secured to the bladder and pelvic floor.

CONCLUSION: This study conceptualized MVs and their role in bladder viability. Increased MVs confer an increased risk of failed BNC. When considering BNC, CBE patients with 3 or more prior MVs may benefit from a pedicled muscle flap, in addition to HAD and pedicled adipose tissue, to prevent fistula development by providing wellvascularized coverage to further reinforce the BNC.