Long-Term Functional and Oncological Outcomes of Patients Undergoing Sural Nerve Interposition Grafting during Robot-Assisted Laparoscopic Radical Prostatectomy

Abstract

For men with high-volume or high-grade prostate cancer, wide excision of the ipsilateral neurovascular bundle is commonly performed. The concept of nerve reconstruction is intriguing as a feasible approach to preserve sexual function (SF). We sought to evaluate the functional, pathologic, and oncologic outcomes of men who underwent robot-assisted sural-nerve graft (SNG) interposition. Between February 2003 and May 2007, 1175 consecutive men underwent robot-assisted laparoscopic radical prostatectomy (RLRP). Database analysis identified 27 men who had SNG: 4 bilateral (BL) and 23 unilateral (UL). SF was prospectively evaluated preoperatively and at 1, 3, 6, 12, and 24 months postoperatively using validated questionnaires. Positive surgical margins (PSMs), biochemical recurrence (BCR), and potency were evaluated. Compared with RLRP patients without SNG, patients with SNG were younger (57.2 v 61.8 years, P=0.02), had a higher Gleason score (P=0.02), and had a higher clinical and pathologic stage (P<0.001 for both). Mean surgical time was significantly longer (349 v 195 min, P<0.001) in patients with SNG. With a mean follow-up of 26.1 months, 11 (47.8%) patients with UL-SNG and zero men with BL-SNG regained potency. No significant difference in SF was observed between UL nerve sparing and no SNG (56%) compared with UL nerve sparing with UL-SNG (P=0.44). Rates of return-to-baseline SF (RTB-SF) at 6, 12, and 24 months were 11%, 36% and 45% for UL-SNG, respectively, which were also comparable to UL nerve sparing only (P>0.05). No patient (0%) in the BL-SNG group ever achieved RTB-SF status at any time point. PSMs were observed in 37% (10/27) of all patients. BCR occurred in nine patients (33.3%), seven of whom had PSM (78%); treatment failure occurred within 6 months of surgery, necessitating androgen deprivation therapy. Despite optimism regarding SNG, long-term functional outcomes have been disappointing, particularly for BL nerve interposition. UL-SNG functional outcomes do not appear to improve outcomes when compared with men with UL nerve preservation. With the greater risk of PSM and BCR in patients who are considered candidates for SNG, newer treatment modalities are needed to cure their disease while preserving SF.