Neurovascular Bundle Stimulation During Robot-Assisted Radical Prostatectomy

Official title

Selective Electrical Stimulation of the Neurovascular Bundles During Robot-Assisted Radical Prostatectomy for Intraoperative Monitoring of Erectile Function

Overview

This prospective first-in-human feasibility study will evaluate the safety and feasibility of selective electrical stimulation of the neurovascular bundles (NVBs) during nerve-sparing robot-assisted radical prostatectomy (RARP). 20 adult patients with localized prostate cancer, normal preoperative erectile function (IIEF \>20), and planned bilateral or unilateral nerve-sparing surgery will be enrolled. During surgery, a custom stimulation probe will deliver low-intensity electrical stimulation to the neurovascular bundles before and after prostate removal. Physiological responses, including penile rigidity, corpus cavernosum electromyography (CC-EMG), penile temperature, galvanic skin response, peripheral pulse, and other intraoperative signals, will be recorded to assess preservation of neurovascular function. The stimulation parameters remain below established safety thresholds for neural tissue. The study aims to determine whether selective neurovascular bundle stimulation is a safe and feasible method for intraoperative functional monitoring during RARP and to generate preliminary data for future clinical studies.

Detailed description

Radical prostatectomy is a standard treatment for localized prostate cancer. Although nerve-sparing robot-assisted radical prostatectomy (RARP) improves functional outcomes, postoperative erectile dysfunction remains common because of injury to the cavernous nerves within the neurovascular bundles (NVBs). Currently, surgeons have limited methods for objectively assessing functional nerve integrity during surgery.

This prospective feasibility study investigates selective electrical stimulation of the NVBs as an intraoperative monitoring technique during RARP. The study will enroll 20 adult patients with localized prostate cancer, normal baseline erectile function (IIEF \>20), and planned nerve-sparing surgery.

A custom-designed stimulation probe based on the selective stimulation model described by Pečlin and Rozman will be applied intraoperatively to the left and right NVBs before and after prostate removal. Medical-grade electrodes will deliver biphasic charge-balanced electrical stimulation within established safety limits that avoid neural tissue injury. The probe will be sterilized using electron beam irradiation.

During stimulation, physiological responses including penile rigidity, corpus cavernosum electromyography (CC-EMG), penile temperature, galvanic skin response, peripheral pulse measurements, and ambient temperature will be recorded. These measurements will be analyzed to assess neurovascular function and compare responses before and after prostate removal.

The primary objective is to evaluate the safety and technical feasibility of selective NVB stimulation during RARP. Secondary objectives include characterization of physiological responses to stimulation and assessment of the potential utility of this technique for intraoperative nerve preservation. Results from this pilot study will provide preliminary evidence to support future larger clinical studies evaluating functional outcomes after nerve-sparing prostatectomy.

Interventions

• Device Selective Neurovascular Bundle Stimulation Probe
  An investigational sterile stimulation probe will be used to deliver biphasic charge-balanced electrical stimulation to the neurovascular bundles during robot-assisted radical prostatectomy. Stimulation will be performed intraoperatively before and after prostate removal using stimulation parameters that remain below established neural injury thresholds. Physiological responses will be recorded to evaluate neurovascular function.

Primary outcome measures

• Safety and technical feasibility of intraoperative selective neurovascular bundle stimulation [Time frame: During the surgical procedure (intraoperative assessment).]

Secondary outcome measures (4)

• Successful acquisition of intraoperative physiological monitoring signals [Time frame: During surgery]
• Physiological responses to neurovascular bundle stimulation [Time frame: During surgery (before and after prostate removal)]
• Investigational device performance [Time frame: During surgery]
• Recovery of erectile function [Time frame: 3, 6, and 12 months after surgery]

Eligibility criteria

Inclusion criteria

• male participants aged 18 years or older;
• histologically confirmed localized prostate cancer;
• scheduled to undergo robot-assisted radical prostatectomy (RARP) with planned unilateral or bilateral nerve-sparing surgery;
• normal preoperative erectile function, defined as an International Index of Erectile Function (IIEF) score >20;
• able and willing to provide written informed consent.

Exclusion criteria

• nerve-sparing surgery is not indicated;
• previous radical prostatectomy or pelvic surgery likely to alter neurovascular bundle anatomy;
• severe pre-existing erectile dysfunction, defined as an IIEF score ≤20;
• contraindication to robot-assisted radical prostatectomy;
• any medical, psychiatric, or other condition that, in the opinion of the investigator, could compromise participant safety, interfere with study participation, or affect interpretation of the study results.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

Slovenia · 1 center

• UMC Ljubljana — Ljubljana

Identifiers

NCT: NCT07724028 · 0120-138/2024-2711-6

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗