Comparison of the anti-reflux ileum valve-pouch orthotopic neobladder and the Studer technique after radical cystecomy: surgical and renal functional outcomes.

BACKGROUND: This study describes the construction of an anti-reflux neobladder using an ileum valve-pouch (IVP) and compares its efficacy with that of the modified Studer-pouch (MSP). METHODS: This study included a total of 127 patients who underwent radical cystectomy + neobladder construction (IVP: n = 66; MSP = 61) between January 2015 and June 2023 at two major medical centers in our city. Potential bias was reduced by 1:1 propensity score matching (PSM) to compare oncology, complications, and renal function protection between the two groups. The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. Survival was assessed using Kaplan-Meier analysis. RESULTS: The median follow-up time was 44.5 and 35.5 months in the IVP and MSP groups, respectively. After propensity scoring, 84 patients (42 in each group) were included in the analysis.There was no significant statistical difference in the operation time(p = 0.128) and the time of urinary diversion (p = 0.354) between the two groups.Kaplan-Meier curves showed no significant differences in cancer-specific survival (CSS) (p = 0.181) and overall survival (OS) (p = 0.611) between the two groups. In addition, the total complications and renal function were not statistically different between the two groups (p > 0.05). The incidence of patients who needed to be re-hospitalized due to urinary tract infection was lower in the VIP group than in the MSP group (p = 0.039). At 12 months postoperatively, lower rates of decreased eGFR and renal function damage were observed in the IVP group compared to the MSP group (p = 0.031 and < 0.001), which were significantly related to the type of neobladder (p = 0.004) and preoperative eGFR values (p < 0.001). CONCLUSION: The preliminary results of VIP technique are safe and effective. It does not increase the time of anti-reflux construction. The incidence of complications similar in the two groups. However, the protection of renal function at 12 months after surgery seemed to be superior to MSP.The independent factors affecting renal function damage are neobladder type and preoperative eGFR.