Bladder augmentation using acellular collagen biomatrix: a pilot experience in exstrophic patients.

Area of Science:

• Regenerative Medicine
• Urology
• Biomaterials Science

Background:

• Exstrophy-epispadias complex often results in poor bladder capacity and compliance after surgical repair.
• Augmentation cystoplasty using bowel segments carries risks, prompting research into alternative regenerative materials.
• Small intestinal submucosa (SIS) is an acellular biomaterial investigated for tissue regeneration.

Purpose of the Study:

• To evaluate the feasibility and efficacy of in vivo bladder wall regeneration using small intestinal submucosa (SIS) in patients with exstrophy-epispadias complex.
• To assess improvements in bladder capacity and compliance without resorting to bowel augmentation.
• To analyze histological changes in the regenerated bladder wall.

Main Methods:

• A cohort of five patients with exstrophy-epispadias complex underwent bladder augmentation with SIS scaffolds.
• Pre- and post-operative assessments included ultrasonography, cystoscopy with cystogram, bladder volume and compliance measurements, and bladder biopsies.
• Histological analysis of biopsies at 6 and 18 months post-surgery was compared to normal bladder tissue.

Main Results:

• Bladder capacity and compliance increased by approximately 30% at 6 months post-surgery, with sustained results at 18 months.
• Histology revealed regenerated bladder tissue with normal mucosa and sero-muscular layers, but a decreased muscle-to-collagen ratio compared to controls.
• No significant improvement in continence was observed, and no adverse events like kidney damage or stones were noted within a 3-year follow-up.

Conclusions:

• Bladder regeneration using SIS scaffolds is technically feasible in patients with exstrophy-epispadias complex.
• While some functional improvement was noted, the increase in bladder capacity and compliance was insufficient for significant clinical benefit or continence achievement.
• The histological findings suggest limited muscle regeneration, indicating that SIS grafting may not provide long-term effective results for this patient population.