Bladder augmentation in anuric/defunctioned microbladders and a novel antireflux mechanism for Mitrofanoff anastomosis to the ileal patch.

BACKGROUND/PURPOSE: Reconstruction of microbladders is a difficult surgical challenge: How can a neobladder be recreated when >90% of the new bladder is augmented patch, and how can a Mitrofanoff conduit be anastomosed when the native bladder is so tiny? This series describes microbladders secondary to anuria and/or diversion that required augmentation. This was done using a de-tubularized ileal segment, and because of the small size of the native bladder, Mitrofanoff anastomosis was performed to the bowel patch (using a novel "Keel Procedure"). METHODS: Our surgical experience in reconstruction of microbladders was reviewed: pre and post augmentation capacity, compliance and maximum detrusor pressure were compared. The success of the Mitrofanoff anti-reflux technique is described. Data are given as median (interquartile range) and compared by Wilcoxon paired rank test. RESULTS: 10 patients, median bladder capacity pre-op 10 (9-20) mls were reconstructed. The follow up time is 2.7years (2.2-4.2). Post-op bladder capacity increased 16-fold to 167 (114-281) mls, P<0.01. Compliance significantly improved from 1.7 (0.3-4.8) to 14.3 (4.1-66.3) mls/cmH2O, P<0.05. Maximum detrusor over-activity decreased from 27 (7-120) to 12.5 (8-26) cmH2O, (N.S. P=0.3). Videourodynamics confirmed a leak in 2 patients, leading to incorporation into the technique of a non-absorbable seromuscular suture to provide long-term robustness to the antireflux procedure. CONCLUSION: Bladder augmentation in microbladders is possible, and a functional Mitrofanoff procedure with a continent anti-reflux procedure can be created using the "Birmingham keel technique" implanting the Mitrofanoff into the augment patch, with 80% success (similar to published results for conventional anastomosis to native bladders). LEVEL OF EVIDENCE: Level IV.

Bladder augmentation with small intestinal submucosa leads to unsatisfactory long-term results.

PURPOSE: To evaluate the use of small intestinal submucosa (SIS) for bladder augmentation in a series of select patients. MATERIAL AND METHODS: Six patients (age 6.5-15.4, mean 9.8 years) underwent bladder augmentation with SIS: one after a cloacal exstrophy repair, one after multiple surgery of the bladder because of vesicoureteral reflux, two with spina bifida, two after bladder exstrophy repair. All suffered from a microbladder with a mean volume of 61.5 ml (range 15-120, 7-36% of expected bladder capacity for age). Preoperative bladder compliance ranged from 1.0 to 3.3 (mean 1.3) ml/cmH2O. RESULTS: Follow-up time ranged from 4.6 to 33.5 (mean 24.4) months. An increase of bladder volume was achieved in four patients (53-370 ml, 16-95% of expected bladder capacity for age). Bladder compliance postoperatively ranged from 0.9 to 5.6 (mean 3.0) ml/cmH2O. Histological examinations showed a complete conversion of SIS, leaving irregular urothelial lining and bladder wall containing muscular, vascular and relatively thick connective tissue in four patients and regular urothelium in two patients. Major complications were bladder stones in two patients and a bladder rupture in one patient. CONCLUSION: Bladder augmentation with SIS in humans failed to fulfill the hopes raised by animal studies. Due to the insufficient increase in bladder compliance and therefore failure to accomplish sufficient protection of the upper urinary tract, bladder augmentation with SIS cannot be recommended as a substitute for enterocystoplasty.