Continuous intraoperative monitoring of autonomic nerves during low anterior rectal resection: an innovative approach for observation of functional nerve integrity in pelvic surgery

Abstract

Purpose: The aim of this study was to develop a methodological setup for continuous intraoperative neuromonitoring with intent to improve nerve-sparing pelvic surgery. Methods: Fourteen pigs underwent low anterior rectal resection. Continuous stimulation of pelvic autonomic nerves was carried out with a newly developed tripolar surface electrode during lateral, anterolateral, and anterior mesorectal dissection. Neuromonitoring was performed under electromyography of the autonomic innervated internal anal sphincter. Results: Continuous neuromonitoring resulted in significantly increased electromyographic amplitudes of the internal anal sphincter, confirming intact innervation throughout the whole dissection in each animal (median 0.9 V, interquartile range 0.5; 1.5 vs. median 3.4 V, interquartile range 2.1; 4.7) (p < 0.001). The median dissection time in each animal was 10 min within a median number of ten (range 8-13) tripolar electric stimulations. Conclusion: The pres ent study is the first to demonstrate that continuous intraoperative monitoring of pelvic autonomic nerves during low anterior rectal resection is feasible

Mapeamento Pélvico: a importância da monitorização de estruturas do sistema nervoso no contexto da endometriose profunda intestinal

“…Esse tipo de estimulação pode levar a lesões não observadas devido aos intervalos de tempo maiores entre duas estimulações. Kauff et al afirma, em seu artigo, que devido à complexidade topográfica da pelve seria necessário o uso de neuromonitoramento intraoperatório contínuo (Kauff, et al, 2012). O neuromonitoramento contínuo é feito por um eletrodo tripolar (IKONA-B1-IKB1, IKONAconsórcio, Alemanha), que é aplicado no esfíncter anal interno com maior aumento de amplitude eletromiográfica.…”

Impact of inhalation vs. intravenous anaesthesia on autonomic nerves and internal anal sphincter tone

“…The electrical neurostimulation is currently performed with a handheld probe, enabling mapping for nerve identification and functional verification in open and laparoscopic procedures . Developments of probe designs for intracorporeal permanent stimulation offered a more continuous neurostimulation, but lack practicability in the clinical routine . Therefore, ongoing research deals with extracorporeal stimulation approaches in order to offer practicable neurostimulation outside the operating area without interruption of the surgical procedure .…”

Surface Electromyography Reliably Records Electrophysiologically Evoked Internal Anal Sphincter Activity: A More Minimally Invasive Approach for Monitoring Extrinsic Innervation

“…Continuous pIONM in a consecutive series of fourteen pigs was found to result in variable amplitude levels during low anterior rectal resection, which underlines the existence of several confounding factors and thus even more the importance of a standardized pIONM procedure [15]. …”