Use of chitosan membranes after nerve-sparing radical prostatectomy improves early recovery of sexual potency: results of a comparative study

Objectives To evaluate the 1-year efficacy of chitosan membrane (ChiMe) application on the neurovascular bundles (NVBs) after nerve-sparing (NS) robot-assisted radical prostatectomy (RARP) in potency recovery rate. To compare the results with those of a contemporary cohort of patients who did not benefit from chitosan use. Patients and Methods Patients in the ChiMe group were enrolled at our institution from July 2015 to September 2016 in a preliminary phase II study. All of them underwent NS-RARP with ChiMe applied on the NVBs and were followed over time to complete a 1-year follow-up. The control group was composed of patients who underwent NS-RARP at our institution without the application of ChiMe from January 2015. The patients were further classified into two groups based on the amount of nerves spared: Group A, comprised patients who underwent a monolateral or bilateral full NS; Group B, comprised patients in which a full NS was not performed. The demographics, peri- and postoperative data, and complications were recorded and compared. Potency recovery was recorded for Group A vs Group B in both the ChiMe and the control groups. Results In all, 136 patients were enrolled in the ChiMe group and 334 patients in the control group. There were no differences between groups in terms of baseline variables. Based on the amount of nerves preserved, 183 patients were included in Group A and 287 in Group B. Odds ratios at different time points showed that the only two factors influencing potency recovery were the amount of nerves preserved (Group A vs Group B) and the application or not of ChiMe on the NVBs spared. Comparing the ChiMe vs control groups at different time points, we found a statistically significant improvement in the potency recovery rate in the ChiMe group at 1 month (36.76% vs 25.88%; P = 0.02) and 2 months (52.2% vs 39.22%; P = 0.01) after surgery, showing a favourable trend at every time point of the entire follow-up period, even if not significant after the second postoperative month. In Group A, the log-rank test showed a statistically significant difference between the ChiMe vs control groups (P = 0.02), in particular at 1 and 2 months after surgery (P = 0.02 and P = 0.01, respectively). Conclusion The application of ChiMe on the NVBs resulted in a higher potency recovery rate at 1 and 2 months after a bilateral or monolateral full NS-RARP. A trend of a higher and shorter potency recovery rate showed it to be favourable to use ChiMe, even in the cohort of patients who did not undergo a full NS procedure.