What ' s known on the subject? and What does the study add? During radical prostatectomy, urological surgeons have tried to identify the " cord-like NVB " at the lateral aspect of the prostate. However, little histological or physiological investigation was conducted to verify that the NVB identifi ed at surgery really included the cavernous nerve. Recently, there have been observations that refute the dogma that the cavernous nerve is always within the NVB.In this study, we have described a hammock-like distribution of the nerves on which the prostate rests, demonstrating that the NVB is more a network of multiple fi ne dispersed nerves than a distinct structure. We presented a novel nerve-sparing approach to complete hammock preservation. This risk-stratifi ed approach for determining the degree of nerve sparing based on the patient ' s likelihood of ipsilateral EPE seeks to categorize patients for optimal balance between oncological outcomes and functional outcomes. OBJECTIVES• To report the potency and oncological outcomes of patients undergoing robotassisted radical prostatectomy (RARP) using a risk-stratifi ed approach based on layers of periprostatic fascial dissection.• We also describe the surgical technique of complete hammock preservation or nerve sparing grade 1. PATIENTS AND METHODS• This is a retrospective study of 2317 patients who had robotic prostatectomy by a single surgeon at a single institution between January 2005 and June 2010.• Included patients were those with ≥ 1 year of follow-up and who were potent preoperatively, defi ned as having a sexual health inventory for men (SHIM) questionnaire score of > 21; thus, the fi nal number of patients in the study cohort was 1263.• Patients were categorized pre-operatively by a risk-stratifi ed approach into risk grades 1 -4, where risk grade 1 patients received nerve-sparing grade 1 or complete hammock preservation and so on for risk grades 2 -4, as long as intraoperative fi ndings permitted the planned nerve sparing.• We considered return to sexual function post-operatively by two criteria: i) ability to have successful intercourse (score of ≥ 4 on question 2 of the SHIM) and ii) SHIM > 21 or return to baseline sexual function. RESULTS• There was a signifi cant difference across different NS grades in terms of the percentages of patients who had intercourse and returned to baseline sexual function ( P < 0.001), with those that underwent NS grade 1 having the highest rates (90.9% and 81.7%) as compared to NS grades 2 (81.4% and74.3%), 3 (73.5% and 66.1%), and 4 (62% and 54.5%).• The overall positive surgical margin (PSM) rates for patients with NS grades 1, 2, 3, and 4 were 9.9%, 8.1%, 7.2%, and 8.7%, respectively ( P = 0.636).• The extraprostatic extension rates were 11.6%, 14.3%, 29.3%, and 36.2%, respectively ( P < 0.001).• Similarly, in patients younger than 60, intercourse and return to baseline sexual function rates were 94.9% and 84.3% for NS grade 1 as compared to 85.5% and 77.2% for NS grades 2, 76.9% and 69% for NS grades 3, and 64.8% and...