MONOLATERAL NERVE-SPARING PROSTATECTOMY: REVIEW OF INDICATIONS, FUNCTIONAL AND ONCOLOGIC OUTCOME

Background and Aim: The literature describes well¬ documented indications for nerve-sparing radical prostatectomy. However, to date, there is no clear reference to the rnonolateral preservation of the bundles. The purpose of this study was to identify patients who are candidates for monolateral nerve-sparing prostatectomy (MRP) and to evaluate the oncologic and functional results. Patients and Methods: The study included 936 patients who underwent consecutive radical retropubic prostatectomy (RRP) for clinically localized prostate cancer. In 463 patients (49.5%), neurovascular bundles were not preserved; in 359 (38.3%) patients, it was possible to preserve both bundles (BRP); while in 114 (12.2%) patients, an MRP was performed. The 114 MRP patients included in the study filled out an IIEF questionnaire pre-operatively and 3, 6, 12, 18 and 24 months after surgery. We performed MRP in patients not suitable for BRP, with Gleason score preoperative ≤ 7, PSA<20 ng/ml, one lobe involvement at biopsy and IIEF-5>19. The Kaplan–Meier method was used to assess the biochemical recurrence-free survival and the x2 test was used to investigate the correlation between MRP and RRP. Results: The mean age at surgery was 62.8 years, mean PSA was 8.52 (range: 3-19.6) ng/ml, 70% of patients had a Gleason score <7 at biopsy and 26.7% of patients had a Gleason score of 7 at biopsy (mean of ten samples, range 6-24) and was positive for cancer bilaterally in 30% of patients (mean of 4 samples, range: 2-7) while in 70% of them only one lobe of the prostate was involved (mean of 3 samples, range: 1-5). The mean preoperative IIEF-5 was 22.1 (range: 14-25). The final histopathological staging showed 56 cases of pT2 (49.2%) and 45 cases of pT3a (39.2%). Thirteen patients with pT3b and pT4 disease and three patients with positive lymph nodes were excluded from the study. In seven patients (7.4%) there were positive surgical margins on the side of the preserved bundle. There was a low incidence of positive surgical margins in the MRP group but it was not statistically significant when we stratified the overall population for RRP, MRP and BRP (12.9,7.4 and 11.5% respectively, p-value was non-significant; MRP vs. RRP, p¬-value was non-significant). The mean follow-up was 48.4 (range: 16-119) months. The biochemical recurrence-free survival for RRP, MRP and BRP at 60 months was 71.7, 80.9 and 86.3%, respectively (p=0.0001; (MRP vs. RRP, p=0.01). Overall, spontaneous sexual potency (or using PDE5-I) was obtained in 62 patients (54.2%) in the MRP group in comparison to 73.1% in the BRP group (p=0.0015). The patients who underwent MRP presented a mean IIEF-5 of 18.3 (range: 5-22) and had a mean age of 62.1 (range: 45-72) years. Conclusion: The retrospettive review of this patient series suggests the potential role of preservation of one of the neurovascular bundles. In this patient series, MRP allowed recovery of sexual function in >50% of patients, with good oncologic outcome. However it is necessary to conduct prospective studies for further evaluation.