Daniel W. Kauff

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 μV (interquartile range [IQR] 0.05, 0.56) vs median 0.89 μV (IQR 0.64, 1.88), p < 0.001) after TME. The patients with the positive IONM results were continent after stoma closure. Of 2 patients with negative IONM results, 1 had fecal incontinence after closure of the defunctioning stoma and received a permanent sigmoidostomy. In the other patient the defunctioning stoma was deemed permanent due to decreased anal sphincter function. In 3 patients who underwent abdominoperineal excision, IONM assessed denervation of the IAS after performance of the abdominal part. CONCLUSIONS This study demonstrated that IONM of IAS innervation in rectal cancer patients is feasible and may predict neurogenic fecal incontinence.

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 internal anal sphincter and manometry of the bladder. Stimulation results were compared to patients’ anorectal and urogenital functional outcome. Results. In all the operations laparoscopic neuromapping (LNM) was technically feasible. Laparoscopy enabled excellent visibility of pelvic neural structures for simple and differentiated electric stimulation. In all cases LNM resulted in significantly evoked electromyographic potentials and intravesical pressure rises. The technique facilitated electrophysiological determination of functional neuroanatomical topography in the minor pelvis. The stimulation results were suitable to confirm laparoscopic nerve-sparing and compatible with patients’ anorectal and urogenital functional outcome. Conclusions. LNM is technically feasible and opens up a new dimension for verification of functional nerve integrity. Further developments and investigations are mandatory to evaluate its role for laparoscopic nerve-sparing procedures.

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 patients using electric stimulation under processed electromyography of IAS (e-TaTME). Results: The indication profile for TaTME was comparable between the v-TaTME and the e-TaTME group. The identification of IRP was more meaningful under electrophysiological assessment than under visual assessment for the left pelvic side (81% vs. 45%, p = 0.008) as well as the right pelvic side (78% vs. 45%, p = 0.016). The identification rates for PSN did not significantly differ between both groups, respectively (81% vs. 75%, p = 0.420 and 84% vs. 70%, p = 0.187). Conclusions: The transanal approach facilitated visual identification of IAS nerve supply. In combination with electrophysiological nerve assessment the identification rate almost doubled. For further insights functional data are needed.

Preconditioning in laparoscopic surgery—results of a virtual reality pilot study

BackgroundThis prospective study investigated the effect of preconditioning in laparoscopic cholecystectomy (LC) and appendectomy (LA) based on pre- and postoperative virtual reality laparoscopy (VRL) performances, with specific regard to the impact of different motor skills, types of surgery and levels of experience.Study designForty laparoscopic procedures (28 LC and 12 LA) were performed by 13 residents in the operating room. Participants completed a defined set of tasks on the VRL simulator directly prior to and after the operation: one preparational task (PT), a virtual procedural task with emphasis on fine preparation (VPT) and a navigational manoeuvre for instrument coordination (ICT). VRL performances were evaluated based on the assessed items of the simulator.ResultsOverall analysis of the surgeons’ performance demonstrated better postoperative results for PT and VPT in 28 and 26 cases (p = 0.001 and p = 0.034), respectively. No significant difference was found for ICT (p = 0.638). Less-experienced residents had better postoperative results for PT and VPT (p = 0.009 and p = 0.041), whereas more-experienced surgeons had better postoperative results for PT only (p = 0.030). LC resulted in better postoperative performance for PT (p = 0.007). LA improved performance for PT and VPT (p = 0.034 and p = 0.006, respectively). Comparisons of surgeon’s experience demonstrated a significant advantage for more-experienced surgeons in ICT (p = 0.033), while type of surgery showed an advantage for LA in VPT (p = 0.022).ConclusionThere is a preconditioning effect in laparoscopic surgery. The differing results related to LC and LA and the experience levels of surgeons suggest that differentiated warm-up strategies are required.

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

Background: 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. Methods: 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. Results: The degree of agreement between electromyography-based and cystomanometry-based IONM with postoperative EF was moderate and good (κ = 0.43 and κ = 0.66). Combined assessment yielded the best agreement (κ = 0.76) with sensitivity of 90%, specificity of 86%, positive predictive value of 90%, negative predictive value of 86%, and overall accuracy of 88%, respectively, in terms of prediction of postoperative EF. Conclusion: The method may be suitable to predict male EF following rectal resection.

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.

Selective Pelvic Autonomic Nerve Stimulation with Simultaneous Intraoperative Monitoring of Internal Anal Sphincter and Bladder Innervation

Background: 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. Methods: 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. Results: Stimulation of IHP and PSN as well as simultaneous intraoperative monitoring could be realized with an adapted neuromonitoring device. Neurostimulation resulted in either bladder or IAS activation or concerted activation of both. Intravesical pressure increase as well as amplitude increase of the IAS neuromonitoring signal did not differ significantly between stimulation of IHP and PSN [6.0 cm H2O (interquartile range [IQR] 3.5–9.0) vs. 6.0 cm H2O (IQR 3.0–10.0) and 12.1 µV (IQR 3.0–36.7) vs. 40.1 µV (IQR 9.0–64.3)] (p > 0.05). Conclusions: Pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of IAS and bladder innervation is feasible. The method may enable neuromonitoring with increasing selectivity for pelvic autonomic nerve preservation.

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

Background: 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. Methods: Six male pigs underwent nerve-sparing low anterior rectal resection. Electric autonomic nerve stimulations were performed under online-processed EMG of the IAS. EMG recordings were simultaneously carried out with conventional bipolar NE as the reference method and newly developed intra-anal surface electrodes (SE) in different designs. Results: In all experiments, the IAS activity could be continuously visualized via EMG recordings based on NE and SE. The median number of bipolar electric stimulations per animal was 27 (range 5-52). The neurostimulations resulted in significant EMG amplitude increases for both recording types [NE: median 3.0 µV (interquartile range, IQR 2.8-3.5) before stimulation vs. 7.1 µV (IQR 3.9-13.8) during stimulation, p < 0.001; SE: median 3.6 µV (IQR 3.1-4.3) before stimulation vs. 6.8 µV (IQR 4.8-10.3) during stimulation, p < 0.001]. Conclusions: Intra-anal SE enabled reliable EMG of electrophysiologically evoked IAS activity similar to the conventional recording via NE. The transfer of the method to access platforms for transanal total mesorectal excision or robotics may offer a practical more minimally invasive approach for monitoring extrinsic innervation.

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

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).

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 throat. For 6 weeks she was treated with methimazole. Laboratory examinations revealed agranulocytosis (total leukocyte count of 0.5 × 109 cells/L, compared to the normal range of 4 to 10 × 109 cells/L, with granulocytes at 0.2% and lymphocytes at 81.3%). The bone marrow aspirate also showed a markedly reduced number ...