Intraoperative neural electrode for continuous monitoring of nerve function

Nerve damage is still a major concern in all types of surgery and may result in permanent nerve injury. Real time nerve monitoring can reduce the risk of nerve lesions by continuous surveillance of nerve integrity. A stable proximal stimulation of the nerve and recording at the effector organ is essential and the electrodes should not significantly influence the surgical intervention.

Risk Factors for Urinary Dysfunction after Rectal Cancer Surgery

Laparoscopic neuromapping in pelvic surgery: scopes of application.

Background. New developments in intraoperative electrophysiological neuromonitoring for conventional surgery are providing further insights into functional neuroanatomy and nerve-sparing in the minor pelvis. The aim of this study was to open up potential scopes of application in laparoscopy. Methods. Ten patients with different indications for surgery (presacral tumor excision, n = 2; resection rectopexy. n = 2; low anterior rectal resection, n = 2; proctocolectomy. n = 2; abdomino-perineal excision of the rectum, n = 2) were investigated prospectively. The pelvic autonomic nerves were bilaterally mapped by laparoscopic electric stimulation under simultaneous electromyography of the intern…

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

Background Pelvic intraoperative neuromonitoring (pIONM) aims to identify and spare the autonomic nerves and maintain patients’ quality of life. The effect of anaesthetic agents on the pIONM signal is unknown; therefore, the aim of the present study was to compare the influences of inhalation anaesthesia (IA) and total intravenous anaesthesia (TIVA). Methods Twenty rectal cancer patients undergoing open nerve-sparing total mesorectal excision (TME) were assigned to pIONM under either IA or TIVA (n = 10 per group). IA was maintained with sevoflurane and TIVA with propofol. During surgery, pelvic autonomic nerves were electrically stimulated under electromyography (EMG) of the internal anal s…

Selective pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of internal anal sphincter and bladder innervation.

<i>Background:</i> Pelvic autonomic nerve preservation avoids postoperative functional disturbances. The aim of this feasibility study was to develop a neuromonitoring system with simultaneous intraoperative verification of internal anal sphincter (IAS) activity and intravesical pressure. <i>Methods:</i> 14 pigs underwent low anterior rectal resection. During intermittent bipolar electric stimulation of the inferior hypogastric plexus (IHP) and the pelvic splanchnic nerves (PSN), electromyographic signals of the IAS and manometry of the urinary bladder were observed simultaneously. <i>Results:</i> Stimulation of IHP and PSN as well as simultaneous intraop…

Synchronous Antithyroid Drug-Induced Agranulocytosis and Fournier Gangrene

ABSTRACT: Objective: Antithyroid drugs (ATDs) such as thioimidazoles (e.g., methimazole, also called thiamazole, and carbimazole) and propylthiouracil are commonly used for the treatment of hyperthyroidism. A life-threatening reaction is agranulocytosis with an incidence of 0.1 to 0.5%. There are very few cases in the literature showing that the intake of ATDs finally led to sepsis with accompanying tissue necrosis.Methods: We present an unusual case of severe symptomatic agranulocytosis with sudden development of Fournier gangrene in a patient who was treated with ATDs for hyperthyroidism due to Graves disease.Results: A 69-year-old female was referred to our hospital with fever and a sore…

Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation.

Background: The current standard for pelvic intraoperative neuromonitoring (pIONM) is based on intermittent direct nerve stimulation. This study investigated the potential use of transcutaneous sacral nerve stimulation for non‐invasive verification of pelvic autonomic nerves. Methods: A consecutive series of six pigs underwent low anterior rectal resection. For transcutaneous sacral nerve stimulation, an array of ten electrodes (cathodes) was placed over the sacral foramina (S2 to S4). Anodes were applied on the back, right and left thigh, lower abdomen, and intra‐anally. Stimulation using the novel method and current standard were performed at different phases of the experiment…

Is intraoperative neuromonitoring associated with better functional outcome in patients undergoing open TME?

Aims: Intraoperative neuromonitoring (IONM) aims to control nerve-sparing total mesorectal excision (TME) for rectal cancer in order to improve patients’ functional outcome. This study was designed to compare the urogenital and anorectal functional outcome of TME with and without IONM of innervation to the bladder and the internal anal sphincter. Methods: A consecutive series of 150 patients with primary rectal cancer were analysed. Fifteen match pairs with open TME and combined urogenital and anorectal functional assessment at follow up were established identical regarding gender, tumour site, tumour stage, neoadjuvant radiotherapy and type of surgery. Urogenital and anorectal function was…

Extracorporeal Stimulation of Sacral Nerve Roots for Observation of Pelvic Autonomic Nerve Integrity: Description of a Novel Methodological Setup.

Introduction: Neurophysiologic monitoring can improve autonomic nerve sparing during critical phases of rectal cancer surgery. Objectives: To develop a system for extracorporeal stimulation of sacral nerve roots. Methods: Dedicated software controlled a ten-electrode stimulation array by switching between different electrode configurations and current levels. A built-in impedance and current level measurement assessed the effectiveness of current injection. Intra-anal surface electromyography (sEMG) informed on targeting the sacral nerve roots. All tests were performed on five pig specimens. Results: During switching between electrode configurations, the system delivered 100% of the set cur…

Surgeons’ assessment of internal anal sphincter nerve supply during TaTME - inbetween expectations and reality

Abstract Background: Intraoperative identification of nerve fibers heading from the inferior rectal plexus (IRP) to the internal anal sphincter (IAS) is challenging. The transanal total mesorectal excision (TaTME) is said to better preserve pelvic autonomic nerves. The aim of this study was to investigate the nerve identification rates during TaTME by transanal visual and electrophysiological assessment. Material and methods: A total of 52 patients underwent TaTME for malignant conditions. The IRP with its posterior branches to the IAS and the pelvic splanchnic nerves (PSN) were visually assessed in 20 patients (v-TaTME). Electrophysiological nerve identification was performed in 32 patient…

Online signal processing of internal anal sphincter activity during pelvic autonomic nerve stimulation: a new method to improve the reliability of intra-operative neuromonitoring signals

Aim  Intra-operative neuromonitoring is increasingly applied in several surgical disciplines and has been introduced to facilitate pelvic autonomic nerve preservation. Nevertheless, it has been considered a questionable tool for the minimization of risk, as the results are variable and might be misleading. The aim of the present experimental study was to develop an intra-operative neuromonitoring system with improved reliability for monitoring pelvic autonomic nerve function. Method  Fifteen pigs underwent low anterior rectal resection with pelvic autonomic nerve preservation. Intra-operative neuromonitoring was performed under autonomic nerve stimulation with observation of electromyograph…

Total mesorectal excision - does the choice of dissection technique have an impact on pelvic autonomic nerve preservation?

Background The aim of this experimental study was to assess the quality of pelvic autonomic nerve preservation of different dissection techniques.

Continuous intraoperative monitoring of pelvic autonomic nerves as a microtechnological navigation instrument

Total mesorectal excision with intraoperative assessment of internal anal sphincter innervation provides new insights into neurogenic incontinence

Background: The aim of this prospective study was to assess internal anal sphincter (IAS) innervation in patients undergoing total mesorectal excision (TME) by intraoperative neuromonitoring (IONM). Study Design: Fourteen patients underwent TME. IONM was carried out through pelvic splanchnic nerve stimulation under continuous electromyography of the IAS. Anorectal function was assessed with the digital rectal examination scoring system and a standardized questionnaire. Results: Nine of 11 patients who underwent low anterior resection had positive IONM results, with stimulation-induced increased IAS electromyographic amplitudes (median 0.23 V (interquartile range [IQR] 0.05, 0.56) vs median …

Intraoperative Monitoring of Bladder and Internal Anal Sphincter Innervation: A Predictor of Erectile Function following Low Anterior Rectal Resection for Rectal Cancer? Results of a Prospective Clinical Study

<b><i>Background:</i></b> The objective was to investigate whether two-dimensional intraoperative neuromonitoring (IONM) of pelvic autonomic nerves has the potential to predict erectile function (EF) following surgery for rectal cancer. <b><i>Methods:</i></b> A consecutive series of 17 sexually active male rectal cancer patients undergoing IONM-based nerve-sparing low anterior rectal resection were evaluated prospectively. IONM was performed by electric stimulation of the pelvic splanchnic nerves with concomitant electromyography of the internal anal sphincter and cystomanometry. Sexual function was assessed using a validated questionnaire. &l…

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

<b><i>Background:</i></b> Even in the case of minimally invasive pelvic surgery, sparing of the autonomic nerve supply is a prerequisite for maintaining anal sphincter function. Internal anal sphincter (IAS) innervation could be electrophysiologically identified based on processed electromyographic (EMG) recordings with conventional bipolar needle electrodes (NE). This experimental study aimed for the development of a minimally invasive approach via intra-anal surface EMG for recordings of evoked IAS activity. <b><i>Methods:</i></b> Six male pigs underwent nerve-sparing low anterior rectal resection. Electric autonomic nerve stimulations were …

Postprocessing algorithm for automated analysis of pelvic intraoperative neuromonitoring signals

Abstract Two dimensional pelvic intraoperative neuromonitoring (pIONM®) is based on electric stimulation of autonomic nerves under observation of electromyography of internal anal sphincter (IAS) and manometry of urinary bladder. The method provides nerve identification and verification of its’ functional integrity. Currently pIONM® is gaining increased attention in times where preservation of function is becoming more and more important. Ongoing technical and methodological developments in experimental and clinical settings require further analysis of the obtained signals. This work describes a postprocessing algorithm for pIONM® signals, developed for automated analysis of huge amount of …