Introduction

1. No. 013 Impact of type of nerve spare procedure on potency outcomes and margin status during Robotic Assisted Radical Prostatectomy. Laurence Harewood 1. and Shomik Sengupta 2. Epworth Health Care Group, and Departments of Urology, Royal Melbourne 1. and Austin 2. Hospitals, Department of Surgery, University of Melbourne. Posters Proudly Supported by: Introduction Return of potency after Radical Prostatectomy (RP) for Cancer of the Prostate is best achieved by a careful preservation of the Neuro Vascular Bundle (NVB) which contains the cavernous nerves. The more aggressive the procedure to preserve the nerves, the more likely it is that a positive surgical margin (+SM) will occur. A +SM has a higher incidence of PSA recurrence post surgery, and hence a compromised oncological outcome. Nerve spare during RP is a balance between preservation of potency and oncological clearance. Results A total of 526 patients were available for study. Clinical Variables: Bilat RGNS/ Bilat NVB p for RGNS AGNS AGNS taken trend Total 280 112 86 48 53.2% 21.3% 16.3% 9.1% D’Amico risk: low 55.7% 16.1% 20.9% 10.4% <0.001 int41.4% 67.9% 52.3% 33.3% NS high 2.9% 16.1% 26.7% 56.3% <0.0001 Pathological stage: pT2 86.8% 63.4% 61.6% 27.1% <0.0001 pT3 13.2% 36.6% 38.4% 72.9% <0.0001 Pathological Gleason score: 6 19.6% 7.1% 5.8% 4.2% <0.0001 7 78.9% 84.8% 80.2% 66.7% NS 8 0.7% 2.7% 5.8% 12.5% <0.0001 9 0.7% 5.4% 8.1% 16.7% <0.0001 Positive margin rates: Bilat RGNS/ Bilat NVB p for RGNS AGNS AGNS taken trend Overall 4.3% 8.9% 10.5% 22.9% <0.0001 pT2 2.1% 0.0% 1.9% 0.0 NS pT3 18.9% 24.4% 24.2% 31.4% NS Potency at 2 years FU: Bilat RGNS/ Bilat NVB p for RGNS AGNS AGNS taken trend Overall 66.1% 53.2% 16.3% 13.6% <0.0001 Good pre 75.8% 69.2% 33.3% 28.6% <0.0005 Figures: Types of Nerve Spare. Aim The aim of this study was to evaluate the return of potency in patients undergoing Robotic Assisted Radical Prostatectomy (RARP) for Cancer of the Prostate, and to correlate this with the type of nerve spare procedure that was undertaken and the positive surgical margin rate that occurred. The purpose was to determine if the aggressiveness of the nerve spare was associated with an improved return of potency, and whether this led to a higher positive surgical margin rate. Retro-grade Intra-fascial Nerve Spare • Methods • A prospective electronic database was kept of all patients undergoing a Robotic Assisted Radical Prostatectomy by a single surgeon. • All clinical parameters were recorded, including preoperative potency and type of nerve spare procedure. Both oncological and functional outcomes were assessed including the positive margin rate and return of potency at 2 years post surgery. • Four categories of nerve spare were carried out. • Bilateral Retrograde or intra-fascial (RGNS): The lateral prostatic fascia was divided on the antero-lateral surface of the prostate and the NVB separated from the capsule of the prostate prior to clipping of the prostatic pedicle. • The most aggressive procedure used in patients with good erections and low or moderate risk disease. • Bilateral Ante-grade or inter-fascial (AGNS): The pedicle was divided prior to dissection of the NVB allowing for an incremental or partial nerve spare. • Done in patients with significant bilateral disease where return of potency was of lower concern. • Unilateral RGNS with contra-lateral AGNS. • Carried out on the side of the tumour in patients with T2 disease where erections were important. • Resection of one or both of the NVBs in patients with high risk, T3 disease. • A positive surgical margin (+SM) was defined as tumour abutting an inked surface on pathological examination. • Potency was defined as the ability to have penetrative sexual intercourse with or without the use of a pde5 drug. Ante-grade Inter-fascial Nerve Spare Discussion The most aggressive NS procedure was the bilateral RGNS (intra-fascial), and this was associated with the best return of potency of 75.8% in patients with good erections pre-operatively. Nevertheless, this also had the lowest overall +ve SM rate of only 4.3% even though 41.4% had D’Amico intermediate risk disease. So long as a RGNS was carried out on at least one side of the prostate, good return of erections was achieved. A bilateral AGNS (intra-fascial) and resection of the NVB on at least one side were both associated with poor return of potency. As the stage and grade of disease increased, the aggressiveness of the type of NS was reduced. Although the +ve SM rate increased with the increasing risk of disease and type of NS, this protocol still achieved a very low overall +ve SM rate across all groups of nerve spare. Conclusion A bilateral retrograde nerve spare provides the best return of potency, and when used in appropriate patients, is associated with a low positive surgical margin rate. Acknowledgements The pathological assessments were made by TissuPath, Melbourne, Australia, with thanks to Associate Professor John Pedersen. Resection of Neuro-vascular Bundle