Neurovascular Structure-Adjacent Frozen-Section Examination Robotic-Assisted Radical Prostatectomy: Outcomes from 500 Consecutive Cases in the UK - Beyond the Abstract

We dutifully published our experience as the leading centre in the UK employing the NeuroSAFE technique in the National Health Service. This was pioneered by the Martini Klinik group in Hamburg, Germany and they have achieved success in >10,000 nerve spare radical prostatectomies using both open and robotic approaches. Our study’s limitation of an unmatched case series, will have uncertainties no doubt addressed by the ongoing UK multicentre NeuroSAFE PROOF RCT.1 Shortly after introducing the robotic platform in our Institute, the majority of nerve spare (NS) RALPs were performed using NeuroSAFE, and hence a control group was not possible in this series.


NeuroSAFE has been employed in various UK and European institutes, and our initial experience in eligibility criteria, lessons of adapting it into the workflow, frozen section result’s length, and subsequent action are key take-home messages. During this learning curve, we have excluded salvage cases, as we believe a nerve spare should not be prioritised over a second attempt of cancer cure. However, after failed focal therapy, the undertaking of salvage surgery should allow for NS with NeuroSAFE of the untreated side. Experience in salvage RALP post focal therapy is limited to high volume centres and we look to their results to guide feasibility. Certainly, it has been published2 that focal therapy is not so focal in collateral tissue effects in non-targeted zones, which may challenge the safety margin of NS whether with FS or not.

The incorporation of extracting the prostate specimen from the camera port and a quick re-establishment of pneumoperitoneum is adaptable with Covidien blunt tip trocar for a da Vinci Si system, as well as Alexis port for da Vinci X/Xi system. The da Vinci Single Port is yet to be adopted to perform NeuroSAFE. When a positive FS was observed, this was confirmed on paraffin analysis in 91.8% of our cases. Furthermore, the likelihood of confirmatory analysis after FS was seen in longer lengths (6 mm) compared to shorter (<2mm).

The importance of a dedicated and audit-compliant histopathology team cannot be overstated. When the neurovascular bundle (NVB) was resected, the analysis of the tissue showed cancer in 26.8% of cases. This would indicate that the tumor had spread beyond the surgical margin in 1 of 4 cases, into what would have been a ‘spared’ NVB without NeuroSAFE.

This publication’s technique is one of many novel advances to increase the efficacy of NS for which many urologists will build further on.3 These advances will also drive contemporary applications of artificial intelligence4 and molecular imaging in radio-guided or fluorescence-guided surgery will improve outcomes post RALP.

Written by: Jonathan Noël, FRCS Urol & Nikhil Vasdev, FRCS Urol

References: 

  1. Dinneen E, Haider A, Grierson J, Freeman A, Oxley J, Briggs T, Nathan S, Williams NR, Brew-Graves C, Persad R, Aning J, Jameson C, Ratynska M, Ben-Salha I, Ball R, Clow R, Allen C, Heffernan-Ho D, Kelly J, Shaw G. NeuroSAFE frozen section during robot-assisted radical prostatectomy: peri-operative and histopathological outcomes from the NeuroSAFE PROOF feasibility randomized controlled trial. BJU Int. 2021 Jun;127(6):676-686. doi: 10.1111/bju.15256. Epub 2021 Mar 29. PMID: 32985121.
  2. Bhat KRS, Covas Moschovas M, Sandri M, Noel J, Reddy S, Perera R, Rogers T, Roof S, Patel VR. Outcomes of Salvage Robot-assisted Radical Prostatectomy After Focal Ablation for Prostate Cancer in Comparison to Primary Robot-assisted Radical Prostatectomy: A Matched Analysis. Eur Urol Focus. 2021 Nov 1:S2405-4569(21)00277-7. doi: 10.1016/j.euf.2021.10.005. Epub ahead of print. PMID: 34736871.
  3. Rocco B, Sarchi L, Assumma S, Cimadamore A, Montironi R, Reggiani Bonetti L, Turri F, De Carne C, Puliatti S, Maiorana A, Pellacani G, Micali S, Bianchi G, Sighinolfi MC. Digital Frozen Sections with Fluorescence Confocal Microscopy During Robot-assisted Radical Prostatectomy: Surgical Technique. Eur Urol. 2021 Dec;80(6):724-729. doi: 10.1016/j.eururo.2021.03.021. Epub 2021 May 6. PMID: 33965288.
  4. Checcucci E, Porpiglia F. The future of robotic radical prostatectomy driven by artificial intelligence. Mini-invasive Surg 2021;5:49 . http://dx.doi.org/10.20517/2574-1225.2021.98

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