The neurovascular structure-adjacent frozen-section examination (NeuroSAFE) approach to nerve sparing in robot-assisted laparoscopic radical prostatectomy in a British setting - a prospective observational comparative study

Objectives: To evaluate the neurovascular structure-adjacent frozen-section examination (NeuroSAFE) technique in a British setting in men undergoing robot-assisted laparoscopic radical prostatectomy (RALP) .

Patients and methods: We retrospectively analysed our prospectively maintained database of patients who underwent RALP between November 2008 and February 2017. We examined preoperative pathological and functional parameters, intraoperative nerve sparing (NS), postoperative histology, as well as functional and oncological follow-up. We compared those who had a NeuroSAFE approach and those who had NS without NeuroSAFE. We also compared all the RALPs before and after the introduction of NeuroSAFE. Statistical analysis was done using the two-tailed t-test and chi-squared analysis.

Results: This single surgeon series included 417 RALPs, including 120 NeuroSAFEs. The NeuroSAFE cohort had a greater proportion of D'Amico high-risk disease (30.8% vs 9.6%, P < 0.001), higher Gleason scores and higher pT stage compared to the non-NeuroSAFE NS cohort. After the introduction of NeuroSAFE, more preoperatively potent men underwent bilateral NS with pT2 disease (84.6% vs 66.3%, P = 0.002) and more overall NS were performed in patients with pT3 disease (65.1% vs 36.7%, P = 0.012). Overall positive surgical margin (PSM) rates were lower in the NeuroSAFE cohort compared to those who had NS without NeuroSAFE (9.2% vs 17.8%, P = 0.04). The 12-month potency rates were also higher in the NeuroSAFE cohort for both bilateral (77.3% vs 50.9%, P = 0.009) and unilateral (70.6% vs 40%, P = 0.04) NS. Pad-free continence was also higher in the NeuroSAFE group (85.7% vs 70.9%, P = 0.019), but there was no significant difference between those who were wearing ≤1 safety pad. Although we only had short-term oncological follow-up, it did not significantly differ between the two groups.

Conclusion: Adoption of NeuroSAFE allowed us to offer NS in higher risk patients, whilst reducing PSM rates and at the same time improving potency at 12 months.