Outcome of tissue engineered cystoplasty augmentation for the treatment of neurogenic bladder by using small intestinal submucosa

Objective To investigate the feasibility and efficacy of using small intestinal submucosa (SIS) as scaffold in cystoplasty augmentation for treating the neurogenic bladder. Methods We retrospectively reviewed our database of 14 patients with neurogenic bladder, including ten male and four female, between January 2011 and March 2014. The mean age in those patients was 29 years old (range 14-56 years old). The etiology of neurogenic bladder included myelomeningoceles in 8 cases and spinal cord injuries in 6 cases. The urodynamic examination showed that the mean volume of maximal bladder pressure was (150.1±64.2) ml, mean bladder compliance was (5.2±3.9) ml/cmH2O, maximal detrusor pressure was (44.1±29.2) cmH2O. The SIS cystoplasty was performed in all patients, which the Surgisis® ES was used during operation. In order to enlarge the bladder, the 4-layer tissue graft was fashioned into a strap shape, rehydrated and continuously sutured to the mucous edge of opening bladder walls. Seven patients accepted the ureter reimplantation with anti-reflux technique simultaneously. Serial video-urodynamics, magnetic resonance urography (MRU) and serum analyses were used to assess the outcomes of surgery. Results All patients were undergone the operation successfully. The mean operative time was 120 min. Bowel function returned promptly after surgery. No metabolic consequences were noted. Renal function was preserved. The duration of follow-up ranged from 6 to 48 months (mean 24 months). Compared to the preoperative findings, there were significant increasing in maximum bladder capacity (P<0.05) at the 6, 12 and 24-month follow-up (150.1±64.2) ml preoperatively, (274.9±88.7) ml at 6 months, (322.5±144.4) ml at 12 months and (279.9±157.9) ml at 24 months, The significant differences also exhibited in the increasing of bladder compliance (P<0.01) at the 24-month follow-up [(5.2±3.9) ml/cmH2O preoperatively, (26.1±29.4) ml/cmH2O at 24 months] and decreasing of maximum detrusor pressure (P<0.05) at the 12 and 24-month follow-up [(44.1±29.2) cmH2O preoperatively, (20.1±9.8) cmH2O at 12 months, (20.2±19.1) cmH2O at 24 months]. Two patients were observed scaffold rupture one week postoperatively and healed with patent drainage. One patient developed calculi in neo-bladder at 3-months follow-up and treated with transurethral lithotripsy. Four patients were noted vesico-ureteral reflux at 12-month follow-up. The botulin toxin detrusor injection was used in 2 cases. After indwelling the catheter for 3 months, the symptoms of reflux disappeared. The oral administration of solifenacin (5mg twice per day) and tolterodine (4mg once per day) was used in other 2 patients, who also accepted the catheter indwelling at the same time. The symptom of reflux relieved in only patient. Conclusions SIS can be used effectively as a scaffold for bladder augmentation. Tissue engineering technology provides a potentially viable option for genitourinary reconstruction in patients with neurogenic bladder. Key words: Tissue engineering; Small intestine submucosa; Cystoplasty augmentation; Neurogenic bladder