(023) FIRST-IN-HUMAN IMPLANTABLE NEUROSTIMULATOR FOR ERECTILE FUNCTION REHABILITATION POST-PROSTATECTOMY: EARLY RESULTS
Authors: Dundee P , Costello A , Crowe H , Cromer M , Rechichi C , Burnett A , Fraga-Silva RA , Stergiopulos N 
Published: December 2024

Abstract

Introduction
Radical prostatectomy (RP) remains a leading cause of erectile dysfunction (ED), primarily due to the inevitable damage to the cavernous nerves. Despite technical improvements in nerve-sparing surgery, post-prostatectomy rates of erectile dysfunction remain unacceptably high. Low-intensity electrostimulation (LIES) has been demonstrated to enhance peripheral nerve regeneration. Indeed, it has been shown that LIES improves erectile function and prevents corpora cavernosal remodeling in animal models of cavernous nerve injury. Recently, an implantable neurostimulator (CaverSTIM) has been developed to deliver electrostimulation to the cavernosal nerves following radical prostatectomy. This is a first-in-human study to evaluate CaverSTIM long-term safety, tolerability, and effectiveness.

Objective
The primary objective of this study is to assess the safety and tolerability of the CaverSTIM device by monitoring the occurrence of adverse events following implantation and to assess the tolerability of cavernous nerve electrostimulation in the post-operative setting. The secondary objectives are to evaluate the effectiveness of LIES in treating and/or rehabilitating erectile function post-prostatectomy.

Methods
Participants with normal pre-operative erectile function undergoing nerve-sparing RP were recruited for this prospective study. CaverSTIM was implanted during robotic-assisted laparoscopic prostatectomy (RALP) and the participants were followed for 6 months. The electrodes were placed bilaterally over the cavernous nerves and the implantable pulse generator was implanted subcutaneously in the lower abdomen. Seven days after implantation, participants were instructed to initiate daily LIES for 1 hour for rehabilitation and after 21 days, normal-intensity stimulation for 15 minutes to induce an increase in cavernosal blood inflow. The erectile function of all participants was assessed before surgery (baseline) and at 44, 90 and 180 days after surgery, using the IIEF-15, EHS and EPIC-26 questionaires and direct measurements of spontaneous nocturnal erections with RigiScan.

Results
In this in-progress study, six patients have been successfully implanted with CaverSTIM. No serious adverse event has been observed and the device is well tolerated. Functional data has been collected from 3 patients until now. A rapid and complete recovery of erectile function was observed in all 3 patients (IIEF-15 erectile funtion (EF) score □SD: 30.0□0.0; 27.7□2.1; 26.5□3.5; 28.0□1.4, at baseline and 44, 90 and 180 days post-surgery, respectively, n = 3), strongly contrasting with published literature showing substantial decreases in the IIEF-15 EF post-prostatectomy. Notably, nocturnal erections also recovered rapidly, with maximum decrease of approximately 30% from baseline at day 90 post-surgery, and complete recovery at 180 days (Rigidity Activity Unit as a percentage of the baseline value □SD: 80.0%; 70.1%; 98.4%, at 14, 90 and 180 days post-surgery respectively, n = 3). These findings contrast sharply with reported significant decreases in nocturnal erection post-prostatectomy, with approximately 90% decrease 28 days after surgery and still 70% diminished after 196 days (McCullough et al, J Sex Med, 2008, Feb;5(2):476-84).

Conclusions
CaverSTIM implantation following RP appears safe and well tolerated. Early results indicate LIES shows promise in the maintenance and restoration of erectile function in post-prostatectomy patients.

Disclosure
Yes, this is sponsored by industry/sponsor: Comphya.
Clarification: Industry initiated, executed and funded study.