Is intraoperative neuromonitoring associated with better functional outcome in patients undergoing open TME? Results of a case-control study

Effect of intermittent urethral catheter clamping combined with active urination training (ICCAUT) strategy on postoperative urinary dysfunction after radical rectal cancer surgery: single-centre randomised controlled trial (ICCAUT -1) study protocol

BACKGROUND

Urinary catheter placement is routinely performed after proctectomy. However, there is uncertainty regarding the need for bladder training before catheter removal. This trial aims to examine the effect of intermittent catheter clamping combined with active urination training (ICCAUT) on urinary retention and secondary catheterisation after proctectomy.

METHODS AND ANALYSIS

Eligible patients will be randomly assigned in a 1:1 ratio to either the ICCAUT group or the free-drainage (FD) group. In the ICCAUT group, patients will undergo intermittent clamping of the urinary catheter combined with active urination training before its removal, whereas the patients in the FD group will not receive any specific training. The urinary catheter will be removed on postoperative day 2 in both groups after emptying the bladder. The primary end point is the incidence of urinary dysfunction. Secondary end points include urinary tract infection, time to first urination after catheter removal, catheter-related bladder discomfort syndrome, postoperative morbidity and mortality and urinary function within 30 days.

ETHICS AND DISSEMINATION

This trial was approved by the Ethics Review Committee of the First Hospital of Jilin University (24K047-001). Written informed consent will be obtained before performing any study procedures. All primary and secondary outcomes will be reported in peer-reviewed publications and at conference presentations.

TRIAL REGISTRATION NUMBER

The trial was registered at ClinicalTrials.gov website, NCT06241703.

Intermittent catheter clamping combined with active urination training (ICCAUT) to reduce the risk of urinary dysfunction in patients after proctectomy: a single-center cohort study

BACKGROUND

Intermittent urethral catheter clamping is widely used to reduce secondary catheterization in patients after proctectomy; however, its effectiveness is unclear.

MATERIALS AND METHODS

This study investigated the effects of intermittent catheter clamping combined with active urination training (ICCAUT) on postoperative urinary dysfunction in patients after proctectomy. This retrospective cohort study analyzed data on patients who underwent laparoscopic/robotic-assisted proctectomy at a single medical center in China between July 2023 and January 2024.

METHODS

Patients received ICCAUT or free urinary drainage during the indwelling urethral catheter period after surgery. Data from the ICCAUT and free-drainage groups were compared. The primary outcome measure was urinary dysfunction. The secondary outcomes were urinary tract infections, time to first void after catheter removal, and urine volume during first voiding. Propensity-score matching (PSM), inverse probability-of-treatment weighting (IPTW), and multivariable logistic regression analyses were used to identify factors associated with urinary dysfunction.

RESULTS

Among 360 eligible patients, 173 received a free-drainage strategy and 187 received ICCAUT. The incidence of urinary dysfunction was 52.5% overall and was significantly lower in the ICCAUT group than in the free-drainage group (45.1% vs. 59.4%; p = 0.009). The lower incidence of urinary dysfunction in the ICCAUT group was confirmed in the PSM (44.7% vs. 59.3%; p = 0.03) and IPTW (44.5% vs. 57.1%; p = 0.028) analyses. Multivariable logistic regression analysis revealed that ICCAUT was independently associated with a lower risk of urinary dysfunction (OR, 0.55; 95% CI, 0.34-0.89; p = 0.015). Subgroup analysis found that, compared with female patients, male patients are more likely to benefit from the ICCAUT strategy (p for interaction = 0.029; adjusted OR, 0.33; 95% CI, 0.17-0.62; p < 0.001). The ICCAUT strategy did not significantly increase the risk of urinary tract infection (p = 0.349).

CONCLUSIONS

The ICCAUT strategy may benefit the recovery of urinary function after proctectomy, especially for male patients. ICCAUT showed an independent association with a lower risk of urinary dysfunction and UTI, with urinary tract infection comparable to that of the free-drainage strategy.

Diagnostic accuracy of intraoperative pelvic autonomic nerve monitoring during rectal surgery: a systematic review

PURPOSE

Anorectal and urogenital dysfunctions are common after rectal surgery and have a significant impact on quality of life. Intraoperative pelvic autonomic nerve monitoring (pIONM) has been proposed as a tool to identify patients at risk of these functional sequelae. This systematic review aims to evaluate the diagnostic accuracy of pIONM in detecting anorectal and urogenital dysfunction following rectal surgery.

METHODS

A systematic review of articles published since 1990 was conducted using MEDLINE, Embase, CINAHL, Google Scholar, Scopus, and Web of Science. Studies describing pIONM for rectal surgery and reporting anorectal or urogenital functional outcomes were included. The risk of bias was assessed using the QUADS-2 tool. The diagnostic accuracy of pIONM was established with pooled sensitivity and specificity alongside summary receiver-operating characteristic curves.

RESULTS

Twenty studies including 686 patients undergoing pIONM were identified, with seven of these studies including a control group. There was heterogeneity in the pIONM technique and reported outcome measures used. Results from five studies indicate pIONM may be able to predict postoperative anorectal (sensitivity 1.00 [95% CI 0.03-1.00], specificity 0.98 [0.91-0.99]) and urinary (sensitivity 1.00 [95% CI 0.03-1.00], specificity 0.99 [0.92-0.99]) dysfunction.

CONCLUSIONS

This review identifies the diagnostic accuracy of pIONM in detecting postoperative anorectal and urogenital dysfunction following rectal surgery. Further research is necessary before pIONM can be routinely used in clinical practice.

PROSPERO REGISTRATION DETAILS

CRD42022313934.

High prevalence of erectile dysfunction within the first year after surgery for rectal cancer: A systematic review and meta-analysis

OBJECTIVE

We aimed to determine the prevalence of erectile dysfunction following rectal cancer surgery within the first year.

SUMMARY BACKGROUND DATA

Erectile dysfunction is a late complication of surgery for rectal cancer. Intraoperative mechanical nerve damage is a probable cause, but it can also be attributed to radio- and chemotherapy.

METHODS

We conducted a systematic review per our protocol (CRD42023472998), searching PubMed, Embase, and Cochrane CENTRAL in August 2023. We included studies reporting on men having surgery for rectal cancer and providing a prevalence of erectile dysfunction based on validated questionnaires published after 1997. The prevalence was estimated through forest plots. Bias was evaluated according to a checklist from the Joanna Briggs Institute.

RESULTS

Of the 4105 records identified in the search, we included 74 studies reporting on 9006 patients operated for rectal cancer. The studies evaluated erectile dysfunction through six validated questionnaires, especially the International Index of Erectile Function (IIEF) version 5 or 15 (84 %). The meta-analysis on 22 studies using IIEF showed that the prevalence of moderate to severe erectile dysfunction was 35 % (95 % CI 24-47 %) within the first year after surgery with very low certainty of evidence. Meta-regression on the prevalence of moderate to severe erectile dysfunction did not show a decrease in erectile dysfunction within the first year postoperatively.

CONCLUSIONS

Around every third patient experienced moderate to severe erectile dysfunction within the first year after surgery for rectum cancer, and the prevalence of erectile dysfunction did not improve within the first year after surgery.

MINI-ABSTRACT

This is a meta-analysis investigating the prevalence of erectile dysfunction following rectal cancer surgery within the first year. Erectile dysfunction was determined on the base of validated self-administered questionnaires. Moderate to severe erectile dysfunction was seen in one-third of patients within the first year after surgery for rectal cancer.

Preventative strategies for low anterior resection syndrome

BACKGROUND

A common and debilitating complication of low anterior resection for rectal cancer is low anterior resection syndrome (LARS). As a multifactorial entity, LARS is poorly understood and challenging to treat. Despite this, prevention strategies are commonly overlooked. Our aim was to review the pathophysiology of LARS and explore current evidence on the efficacy and feasibility of prophylactic techniques.

METHODS

A literature review was performed between [1st January 2000 to 1st October 2023] for studies which investigated preventative interventions for LARS. Mechanisms by which LARS develop are described, followed by a review of prophylactic strategies to prevent LARS. Medline, Cochrane, and PubMed databases were searched, 189 articles screened, 8 duplicates removed and 18 studies reviewed.

RESULTS

Colonic dysmotility, anal sphincter dysfunction and neorectal dysfunction all contribute to the development of LARS, with the complex mechanism of defecation interrupted by surgery. Transanal irrigation (TAI) and pelvic floor rehabilitation (PFR) have shown benefits in preventing LARS, but may be limited by patient compliance. Intraoperative nerve monitoring (IONM) and robotic-assisted surgery have shown some promise in surgically preventing LARS. Nerve stimulation and other novel strategies currently used in treatment of LARS have yet to be investigated in their roles prophylactically.

CONCLUSIONS

To date, there is a limited evidence base for all preventative strategies including IONM, RAS, PFP and TAI. These strategies are limited by either access (IONM, RAS and PFP) or acceptability (PFP and TAI), which are both key to the success of any intervention. The results of ongoing trials will serve to assess acceptability, while technological advancement may improve access to some of the aforementioned strategies.

The erectile and ejaculatory implications of the surgical management of rectal cancer

Colorectal cancer is a significant cause of cancer-related deaths worldwide. Although advances in surgical technology and technique have decreased mortality rates, surviving patients often experience sexual dysfunction as a common complication. The development of the lower anterior resection has greatly decreased the use of the radical abdominoperineal resection surgery, but even the less radical surgery can result in sexual dysfunction, including erectile and ejaculatory dysfunction. Improving the knowledge of the underlying causes of sexual dysfunction in this context and developing effective strategies for preventing and treating these adverse effects are essential to improving the quality of life for postoperative rectal cancer patients. This article aims to provide a comprehensive evaluation of erectile and ejaculatory dysfunction in postoperative rectal cancer patients, including their pathophysiology and time course and strategies for prevention and treatment.

Pelvic Intraoperative Neuromonitoring Prevents Dysfunction in Patients With Rectal Cancer: Results From a Multicenter, Randomized, Controlled Clinical Trial of a NEUROmonitoring System (NEUROS)

OBJECTIVE

This NEUROmonitoring System (NEUROS) trial assessed whether pelvic intraoperative neuromonitoring (pIONM) could improve urogenital and ano-(neo-)rectal functional outcomes in patients who underwent total mesorectal excisions (TMEs) for rectal cancer.

BACKGROUND

High-level evidence from clinical trials is required to clarify the benefits of pIONM.

METHODS

NEUROS was a 2-arm, randomized, controlled, multicenter clinical trial that included 189 patients with rectal cancer who underwent TMEs at 8 centers, from February 2013 to January 2017. TMEs were performed with pIONM (n=90) or without it (control, n=99). The groups were stratified according to neoadjuvant chemoradiotherapy and sex, with blocks of variable length. Data were analyzed according to a modified intention-to-treat protocol. The primary endpoint was a urinary function at 12 months after surgery, assessed with the International Prostate Symptom Score, a patient-reported outcome measure. Deterioration was defined as an increase of at least 5 points from the preoperative score. Secondary endpoints were sexual and anorectal functional outcomes, safety, and TME quality.

RESULTS

The intention-to-treat analysis included 171 patients. Marked urinary deterioration occurred in 22/171 (13%) patients, with significantly different incidence between groups (pIONM: n=6/82, 8%; control: n=16/89, 19%; 95% confidence interval, 12.4-94.4; P =0.0382). pIONM was associated with better sexual and ano-(neo)rectal function. At least 1 serious adverse event occurred in 36/88 (41%) in the pIONM group and 53/99 (54%) in the control group, none associated with the study treatment. The groups had similar TME quality, surgery times, intraoperative complication incidence, and postoperative mortality.

CONCLUSION

pIONM is safe and has the potential to improve functional outcomes in rectal cancer patients undergoing TME.

Intraoperative Neuromonitoring for Pediatric Pelvic Tumors

Background

Tumors of the pre-sacral and sacral spaces are a rare occurrence in children. Total tumor excision is required due to the significant risk of relapse in the event of partial surgery, but the surgical procedure may lead to postoperative problems such as urinary, sexual, and anorectal dysfunctions. Intraoperative neuromonitoring (IONM) has gained popularity in recent years as a strategy for preventing the onset of neurologic impairments by combining several neurophysiological techniques. The aim of our study is to describe the experience of Bambino Gesù Children's Hospital in the use of IONM in pediatric pelvic surgery.

Materials and Methods

The data of patients treated for pelvic malignancies at Bambino Gesù Children's Hospital from 2015 to 2019 were retrospectively collected. All patients were assessed from a neurologic and neuro-urologic point of view at different time-points (before and immediately after surgery, after 6 months, and 1-year follow-up). They were all monitored during a surgical procedure using multimodal IONM including transcranial motor evoked potentials (TcMEP), triggered-EMG (t-EMG), pudendal somatosensory evoked potentials (PSSEP), and bulbocavernosus reflex (BCR).

Results

During the study period, ten children underwent pelvic tumor removal at our Institution. In all cases, intraoperative neurophysiological recordings were stable and feasible. The preservation of neurophysiological response at the same intensity during surgical procedures correlated with no new deficits for all neurophysiological techniques.

Discussion

Although the impact of the IONM on surgical strategies and clinical follow-up is unknown, this preliminary experience suggests that the appropriate use of several neurophysiological techniques can influence both the radicality of pelvic tumor removal and the neurological and urological outcome at clinical follow-up. Finally, because of the highly complex anatomy and inter-individual variances, this is especially useful in this type of surgery.

Intraoperative neuromonitoring in rectal cancer surgery: a systematic review and meta-analysis

PURPOSE

The aim of this study is to evaluate the role of pelvic intraoperative neuromonitoring (pIONM) in rectal cancer surgery.

METHODS

A systematic review of the literature and a meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Overall, nine studies were identified. Quantitative analysis was performed only in three trials. Bilateral pIONM improved postoperative anorectal and urogenital functional outcomes. However, unilateral pIONM displayed a significant effect only on erectile function (p = 0.001).

CONCLUSIONS

Our findings suggest a positive effect of pIONM on postoperative functional outcomes and quality of life after rectal cancer surgery. Due to several limitations, further trials are required in order to elucidate the exact role of pIONM.

Multicenter investigation of bowel evacuation function after transanal total mesorectal excision for mid-low rectal cancer

PURPOSE

To determine the effect of transanal total mesorectal excision (taTME) procedure on the postoperative bowel evacuation function of patients with low rectal cancer.

METHODS

Bowel evacuation function was investigated in 316 patients with rectal cancer after taTME in 18 hospitals in China. Low anterior resection syndrome (LARS) score, Wexner score, and EORTC QLQ-C30 were used for functional evaluation. The association between perioperative risk factors and LARS score was determined by univariate and multivariate analyses.

RESULTS

The prevalence rate of no LARS, minor LARS, and major LARS in patients after taTME was 39.9%, 28.2%, and 31.9%, respectively. The two most frequently reported symptoms of LARS after taTME were bowel clustering (72.8%) and fecal urgency (63.3%). Patients with major LARS had significantly higher Wexner score and worse global health status and financial difficulties according to the EORTC QLQ-C30 questionnaire than those without major LARS. Preoperative chemoradiotherapy was an independent risk factor of major LARS occurrence after taTME (OR: 3.503, P = 0.044); existing preoperative constipation (OR: 0.082, P = 0.040) and manual anastomosis (OR: 4.536, P = 0.021) were favorable factors affecting bowel evacuatory function within 12 months after taTME, but for patients whose follow-up time was longer than 12 months, postoperative chemoradiotherapy (OR: 8.790, P = 0.001) and defunctioning stoma (OR: 3.962, P = 0.010) were independent risk factors.

CONCLUSIONS

The bowel evacuation function after taTME is acceptable. Perioperative chemoradiotherapy, anastomotic method, and preoperative constipation are factors associated with bowel dysfunction after taTME.

Tools for fecal incontinence assessment: lessons for inflammatory bowel disease trials based on a systematic review

BACKGROUND

Fecal incontinence is a disabling condition affecting up to 20% of women.

OBJECTIVE

We investigated fecal incontinence assessment in both inflammatory bowel disease and non-inflammatory bowel disease patients to propose a diagnostic approach for inflammatory bowel disease trials.

METHODS

We searched on Pubmed, Embase and Cochrane Library for all studies on adult inflammatory bowel disease and non-inflammatory bowel disease patients reporting data on fecal incontinence assessment from January 2009 to December 2019.

RESULTS

In total, 328 studies were included; 306 studies enrolled non-inflammatory bowel disease patients and 22 studies enrolled inflammatory bowel disease patients. In non-inflammatory bowel disease trials the most used tools were the Wexner score, fecal incontinence quality of life questionnaire, Vaizey score and fecal incontinence severity index (in 187, 91, 62 and 33 studies). Anal manometry was adopted in 41.2% and endoanal ultrasonography in 34.0% of the studies. In 142 studies (46.4%) fecal incontinence evaluation was performed with a single instrument, while in 64 (20.9%) and 100 (32.7%) studies two or more instruments were used. In inflammatory bowel disease studies the Wexner score, Vaizey score and inflammatory bowel disease quality of life questionnaire were the most commonly adopted tools (in five (22.7%), five (22.7%) and four (18.2%) studies). Anal manometry and endoanal ultrasonography were performed in 45.4% and 18.2% of the studies.

CONCLUSION

Based on prior validation and experience, we propose to use the Wexner score as the first step for fecal incontinence assessment in inflammatory bowel disease trials. Anal manometry and/or endoanal ultrasonography should be taken into account in the case of positive questionnaires.

Technique of neuromonitoring during pelvic peritonectomy

OBJECTIVES

Pelvic peritonectomy can induce anorectal and urogenital dysfunctions. To reduce this type of complications during the procedure, we propose to use intraoperative neuromonitoring (IONM).

CONTENT

Stimulation with a bipolar probe allows the identification of the obturator and ilioinguinal and pudendal nerves. At the end of the cytoreductive surgery, the motor and somatosensory evoked potentials must be evaluated to confirm the preservation of pelvic innervation.

SUMMARY

The use of IONM during pelvic peritonectomy is technically feasible, and it can help to preserve pelvic nerves.

OUTLOOK

Obviously, its definitive value remains to be elucidated.

Optimising functional outcomes in rectal cancer surgery

Background

By improved surgical technique such as total mesorectal excision (TME), multimodal treatment and advances in imaging survival and an increased rate of sphincter preservation have been achieved in rectal cancer surgery. Minimal-invasive approaches such as laparoscopic, robotic and transanal-TME (ta-TME) enhance recovery after surgery. Nevertheless, disorders of bowel, anorectal and urogenital function are still common and need attention.

Purpose

This review aims at exploring the causes of dysfunction after anterior resection (AR) and the accordingly preventive strategies. Furthermore, the indication for low AR in the light of functional outcome is discussed. The last therapeutic strategies to deal with bowel, anorectal, and urogenital disorders are depicted.

Conclusion

Functional disorders after rectal cancer surgery are frequent and underestimated. More evidence is needed to define an indication for non-operative management or local excision as alternatives to AR. The decision for restorative resection should be made in consideration of the relevant risk factors for dysfunction. In the case of restoration, a side-to-end anastomosis should be the preferred anastomotic technique. Further high-evidence clinical studies are required to clarify the benefit of intraoperative neuromonitoring. While the function of ta-TME seems not to be superior to laparoscopy, case-control studies suggest the benefits of robotic TME mainly in terms of preservation of the urogenital function. Low AR syndrome is treated by stool regulation, pelvic floor therapy, and transanal irrigation. There is good evidence for sacral nerve modulation for incontinence after low AR.

Fecal incontinence after total mesorectal excision for rectal cancer-impact of potential risk factors and pelvic intraoperative neuromonitoring

BACKGROUND

Fecal incontinence frequently occurs after total mesorectal excision for rectal cancer. This prospective study analyzed predictive factors and the impact of pelvic intraoperative neuromonitoring at different follow-up intervals.

METHODS

Fifty-two patients were included undergoing total mesorectal excision for rectal cancer, and 29 under control of pelvic intraoperative neuromonitoring. Fecal incontinence was assessed using the Wexner Score at 3 and 6 months after stoma closure (follow-ups 1 and 2) as well as 1 and 2 years after surgery (follow-ups 3 and 4). Risk factors were identified by means of logistic regression.

RESULTS

New onset of fecal incontinence was significantly lower in the neuromonitoring group at each follow-up (follow-up 1: 2 of 29 patients (7%) vs. 8 of 23 (35%), (p = 0.014); follow-up 2: 3 of 29 (10%) vs. 9 of 23 (39%), (p = 0.017); follow-up 3: 5 of 29 (17%) vs. 11 of 23 (48%), p = 0.019; follow-up 4: 6 of 28 (21%) vs. 11 of 22 (50%), p = 0.035). Non-performance of neuromonitoring was found to be an independent predictor for fecal incontinence throughout the survey. Neoadjuvant chemoradiotherapy was an independent predictor in the further course 1 and 2 years after surgery.

CONCLUSIONS

Performance of pelvic intraoperative neuromonitoring is associated with significantly lower rates of fecal incontinence. Neoadjuvant chemoradiotherapy was found to have negative late effects. This became evident 1 year after surgery.

Oncological Outcomes and Quality of Life After Rectal Cancer Surgery

Surgery for rectal cancer has been completely revolutionized thanks to the adoption of new technologies and up-to-date surgical procedures that have been applied to the traditional milestone represented by Total Mesorectal Excision (TME). The multimodal and multidisciplinary approach, with new technologies increased the patients' life expectancies; nevertheless, they have placed the surgeon in front of newer issues, represented by both oncological outcomes and the patients' need of a less destructive surgery and improved quality of life. In this review we will go through laparoscopic, robotic and transanal TME surgery, to show how the correct choice of the most appropriate technique, together with a deep knowledge of oncological principles and pelvic anatomy, is crucial to pursue an optimal cancer treatment. Novel technologies might also help to decrease the patients' fear of surgery and address important issues such as cosmesis and improved preservation of postoperative functionality.

To what extent is the low anterior resection syndrome (LARS) associated with quality of life as measured using the EORTC C30 and CR38 quality of life questionnaires?

PURPOSE

Treatment of rectal cancer often results in disturbed anorectal function, which can be quantified by the Low Anterior Resection Syndrome (LARS) score. This study investigates the association of impaired anorectal function as measured with the LARS score with quality of life (QoL) as measured with the EORTC-QLQ-C30 and CR38 questionnaires.

METHODS

All stoma-free patients who had undergone sphincter-preserving surgery for rectal cancer from 2000 to 2014 in our institution were retrieved from a prospective database. They were contacted by mail and asked to return the questionnaires. QoL was evaluated in relation to LARS and further patient- and treatment factors using univariate and multivariate analysis.

RESULTS

Of the eligible patients (n = 331), 261 (78.8%) responded with a complete LARS score. Mean score for global QoL according to the EORTC-QLQ-C30 questionnaire was 63 ± 21 for all patients. If major LARS was present, mean score decreased to 56 ± 19 in contrast to 67 ± 20 in patients with no/minor LARS (p < 0.001). In regression analysis, major LARS was furthermore associated with reduced physical, role, emotional, cognitive and social functioning as well as impaired body image, more micturition problems and poorer future perspective. It was not related to sexual function. The variance explained by major LARS in the differences of QoL was approximately 10%.

CONCLUSION

The presence of major LARS after rectal resection for cancer is negatively associated with global health as well as many other aspects of QoL. Preserving anorectal function and treatment of LARS are potential measures to improve QoL in this patient group.

Intraoperative monitoring of pelvic autonomic nerves during laparoscopic low anterior resection of rectal cancer

Background

Some patients with low rectal cancer experience anorectal and urogenital dysfunctions after surgery, which can influence the long-term quality of life. In this study, we aimed to protect nerve function in such scenarios by performing intraoperative monitoring of pelvic autonomic nerves (IMPAN).

Patients and methods

We retrospectively investigated a series of 87 patients undergoing laparoscopic low anterior resection of rectal cancer. Nerve-sparing was evaluated both visually and electrophysiologically. IMPAN was performed by stimulating the pelvic autonomic nerves under processed electromyography of the internal anal sphincter. Urination, defecation, sexual function, and the quality of life were evaluated using validated and standardized questionnaires preoperatively and at follow-up, 12 months after surgery.

Results

Among a total of 87 patients (53 male and 34 female patients), IMPAN with simultaneous electromyography of the internal anal sphincter was performed in 58 (66.7%) patients. Bilateral positive IMPAN results for both measurements, indicating successfully confirmed pelvic autonomic nerve preservation, were obtained in 45 (51.7%) patients. No significant difference was found in terms of urogenital and anorectal functions between preoperative and postoperative patients with bilateral positive IMPAN (P>0.05). Compared to preoperative patients with IMPAN (unilateral) or without IMPAN, these patients exhibited higher International Prostate Symptom Score, a lower International Index of Erectile Function-5, and a lower Female Sexual Function Index score at 12 months postoperatively (P<0.05).

Conclusion

IMPAN is an appropriate method with which to laparoscopically protect nerve function.

Outcome of bowel function following anterior resection for rectal cancer-an analysis using the low anterior resection syndrome (LARS) score

PURPOSE

Severity of anorectal dysfunction after low anterior resection is associated with various patient- and treatment-related factors. We aimed to quantify anorectal dysfunction after treatment for rectal cancer using the low anterior resection syndrome (LARS) score.

METHODS

We retrieved from a prospective database 331 eligible patients on whom anterior resection for rectal cancer had been performed from 2000 to 2014. All patients were sent a LARS score accompanied by a supplementary questionnaire. Response rate was 78.8% (261 patients). The main outcome measure was the relation of the LARS score to potentially associated patient and treatment factors. Secondary endpoints were further measures that reflect anorectal dysfunction, e.g., Vaizey score.

RESULTS

Overall, 144 (55.2%) patients exhibited scores > 20 reflecting minor (n = 51 (19.5%)) or major (n = 93 (35.6%)) LARS. A significant difference for scores > 20 was found for intersphincteric resection (IR, 73.2% affected patients) compared to total mesorectal excision (TME, 58.4%) and partial mesorectal excision (PME, 38.0%, p = 0.001). Radio(chemo)therapy resulted in LARS scores > 20 in 64.6% of patients compared to 43.1% in patients without irradiation (p = 0.001). Type of procedure (TME and IR as compared to PME), radio(chemo)therapy, and younger age were independently associated with LARS in logistic regression analysis. However, younger age remained the only independent factor for higher scores after exclusion of PME.

CONCLUSIONS

The LARS score identified a substantial proportion of patients after surgery for rectal cancer with anorectal dysfunction. The extent of surgical procedure is independently associated with the severity of symptoms whereas the role of radiotherapy needs further assessment.

Intraoperative monitoring of neuromuscular function with soft, skin-mounted wireless devices

Peripheral nerves are often vulnerable to damage during surgeries, with risks of significant pain, loss of motor function, and reduced quality of life for the patient. Intraoperative methods for monitoring nerve activity are effective, but conventional systems rely on bench-top data acquisition tools with hard–wired connections to electrode leads that must be placed percutaneously inside target muscle tissue. These approaches are time and skill intensive and therefore costly to an extent that precludes their use in many important scenarios. Here we report a soft, skin-mounted monitoring system that measures, stores, and wirelessly transmits electrical signals and physical movement associated with muscle activity, continuously and in real-time during neurosurgical procedures on the peripheral, spinal, and cranial nerves. Surface electromyography and motion measurements can be performed non-invasively in this manner on nearly any muscle location, thereby offering many important advantages in usability and cost, with signal fidelity that matches that of the current clinical standard of care for decision making. These results could significantly improve accessibility of intraoperative monitoring across a broad range of neurosurgical procedures, with associated enhancements in patient outcomes.

A small skin-mounted biosensing device accurately and non-invasively monitors neuromuscular activity in real-time during surgery. With many surgical procedures there is a risk of nerve damage. Although this is often temporary, in some cases it can significantly affect patients’ quality of life. Existing monitoring systems that rely on the accurate placement of needle electrodes into target nerves are cumbersome and expensive. The device developed by a team led by John Rogers, at Northwestern University, and Michel Kliot, at Stanford University, can easily be accommodated to any part of the body to monitor muscle activity in response to nerve impulses and stimulation during surgery. Furthermore, it can wirelessly transmit signals of comparable quality to needle-based systems. These devices could not only increase the use of intraoperative monitoring in hospitals but also contribute to make surgery safer.

Internal anal sphincter nerves - a macroanatomical and microscopic description of the extrinsic autonomic nerve supply of the internal anal sphincter

AIM

The internal anal sphincter (IAS) contributes substantially to anorectal functions. While its autonomic nerve supply has been studied at the microscopic level, little information is available concerning the macroscopic topography of extrinsic nerve fibres. This study was designed to identify neural connections between the pelvic plexus and the IAS, provide a detailed topographical description, and give histological proof of autonomic nerve tissue.

METHODS

Macroscopic dissection of pelvic autonomic nerves was performed under magnification in seven (five male, two female) hemipelvises obtained from body donors (67-92 years). Candidate structures were investigated by histological and immunohistochemical staining protocols to visualize nerve tissue.

RESULTS

Nerve fibres could be traced from the anteroinferior edge of the pelvic plexus to the anorectal junction running along the neurovascular bundle anterolaterally to the rectum and posterolaterally to the prostate/vagina. Nerve fibres penetrated the longitudinal rectal muscle layer just above the fusion with the levator ani muscle (conjoint longitudinal muscle) and entered the intersphincteric space to reach the IAS. Histological and immunohistochemical findings confirmed the presence of nerve tissue.

CONCLUSIONS

Autonomic nerve fibres supplying the IAS emerge from the pelvic plexus and are distinct to nerves entering the rectum via the lateral pedicles. Thus, they should be classified as IAS nerves. The identification and precise topographical location described provides a basis for nerve-sparing rectal resection procedures and helps to prevent postoperative functional anorectal disorders.

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 experiments under electromyography of the autonomic innervated internal anal sphincter (IAS).

KEY RESULTS

Transcutaneous stimulation induced increase of IAS activity could be observed in each animal under specific cathode-anode configurations. Out of 300 tested configurations, 18 exhibited a change in the IAS activity correlated with intentional autonomic nerve damage. The damage resulted in a significant decrease of the relative area under the curve of the IAS frequency spectrum (P<.001). Comparison of the IAS spectra under transcutaneous and direct stimulation revealed no significant difference (after rectal resection: median 5.99 μV•Hz vs 7.78 μV•Hz, P=.12; after intentional nerve damage: median -0.27 μV•Hz vs 3.35 μV•Hz, P=.29).

CONCLUSIONS AND INFERENCES

Non-invasive selective transcutaneous sacral nerve stimulation could be used for verification of IAS innervation.

Risk Factor Analysis for Newly Developed Urogenital Dysfunction after Total Mesorectal Excision and Impact of Pelvic Intraoperative Neuromonitoring-a Prospective 2-Year Follow-Up Study

AIM

Urogenital dysfunction is a common sequela following total mesorectal excision for rectal cancer. This prospective study analyzed potential risk factors and investigated the impact of pelvic intraoperative neuromonitoring.

METHOD

Included were 85 patients undergoing total mesorectal excision for rectal cancer, 43 under the control of pelvic intraoperative neuromonitoring. Urogenital function was assessed with validated questionnaires within a 2-year follow-up period. Potential risk factors were identified by multivariate analysis.

RESULTS

Overall, approximately one-third of treated patients suffered from new onset of urinary dysfunction. Initially, half of the sexually active patients were affected by sexual dysfunction; after 2 years, almost three quarters were affected. In the pelvic intraoperative neuromonitoring group, urinary and sexual dysfunction rates including minor and major disturbances were significantly lower (2-year follow-up 20% vs. 51% (p = 0.004) and 56% vs. 90% (p = 0.010)). Throughout the survey, non-performance of pelvic intraoperative neuromonitoring was found to be an independent risk factor. Neoadjuvant chemoradiotherapy was identified as an independent predictor for urogenital dysfunction in the further course one and 2 years after surgery.

CONCLUSION

Pelvic intraoperative neuromonitoring is associated with significantly lower rates of urinary and sexual dysfunction in the short and long run, whereas neoadjuvant chemoradiotherapy has a negative impact only in the long run.

Intraoperative neuromonitoring of hypogastric plexus branches during surgery for rectal cancer - preliminary report

AIM

The aim of this study was to present our preliminary experience with intraoperative neuromonitoring during rectal resection.

MATERIALS AND METHODS

We qualified 4 patients (2 women, 2 men; age 42 - 53 years) with rectal cancer for surgery with intraoperative neuromonitoring. In all patients, functional tests of the anorectal area were performed before surgery. Action potentials from the sphincter complex in response to nerve fiber stimulation were recorded with electrodes implanted before surgery. Moreover, we inserted a standard, 18FR Foley's urinary catheter to which a T-tube was connected to allow urine outflow and measurement of pressure changes in the bladder induced by detrusor contractions during stimulation.

RESULTS

Setting up neuromonitoring prolonged surgery time by 30 to 40 minutes, or even by 60 to 80 minutes in the case of the first two patients. Neuromonitoring itself took additional 20 to 30 minutes during surgery. In all patients, we stimulated branches of the inferior hypogastric plexus in their anatomical position during dissection. In three patients, we evoked responses both from the bladder and the sphincter in all planes of stimulation. In one patient, there was no response from the left side of the bladder, and in the same patient, we observed symptoms of neurogenic bladder.

CONCLUSIONS

Based on the available literature and our own experience, we state that monitoring of bladder pressure and electromyographic signals from rectal sphincters enables visualization and preservation of autonomic nervous system structures, both sympathetic and parasympathetic. Intraoperative signals seem to be correlated with clinical presentation and functional examinations after surgery. In order to objectify our results, it is necessary to perform functional examinations before and after surgery in a larger group of patients.

Anorectal functional outcome following laparoscopic low anterior resection for rectal cancer

Low anterior resection (LAR) with total mesorectal excision has been considered a standard treatment for patients with rectal cancer. However, the functional outcome and life quality of laparoscopic LAR (LLAR) in Chinese patients remain unclear. A cohort of 51 Chinese patients (22 men and 29 women) who had undergone LLAR was included in this study. Anorectal manometry combined with the Wexner scores questionnaire were applied to assess functional outcome preoperatively (1 week) and postoperatively (at 3, 6 and 9 months). The validated Chinese versions of the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires were also used to assess the patients' quality of life at the indicated time points. The results demonstrated that the manometric parameters exhibited a temporary decrease at 3 months postoperatively, but a gradual increase at 6 and 9 months, while the Wexner scores exhibited an opposite trend. Furthermore, patients with high anastomoses had significantly higher manometric parameters, a lower frequency of incontinence and lower Wexner scores compared with those with low anastomoses at 9 months (all P<0.05). For the entire cohort, quality of life at 3 months postoperatively was worse compared with the preoperative level, but returned to normal by 9 months. Patients with high anastomoses exhibited significantly better role, emotional and social function, had a better body image and sexual function, fewer problems with defecation and lower frequency of diarrhea, as well as fewer chemotherapy-related side effects at 6 months postoperatively when compared with the low anastomosis group (all P<0.05). In conclusion, LLAR is generally acceptable for Chinese patients with rectal cancer, particularly for those with middle or high rectal cancer, in terms of functional outcome and quality of life.

Genito-urinary sequelae after carcinological rectal resection: What to tell patients in 2017

Although we have seen revolutionary changes with multi-disciplinary management of patients with rectal cancer, the evaluation of genito-urinary sequelae remains of great concern. Precise pre-operative evaluation with validated scores allows detection of urinary disorders in 16 to 23% of patients, and sexual disorders in nearly 35% of men and 50% of women. Regardless of the surgical approach, it is fundamental to respect the autonomic innervation during total mesorectal excision in order to prevent these sequelae. Identification of these nerves can be facilitated by intra-operative neuro-stimulation. In spite of these precautions, de novo urinary sequelae are observed in nearly 33% of patients and bladder evacuation disorders in 25% of patients. Advanced age, pre-operative urinary disorders, female gender, and abdomino-perineal resection are independent risk factors for urinary sequelae. Early post-operative urodynamic abnormalities might be predictive of these sequelae and justify early physiotherapy. Likewise, sexual sequelae such as erectile and/or ejaculatory disorders, dyspareunia and lubrication deficits result in de novo cessation of sexual activity in 28% of men and 18% of women. Advanced age, neo-adjuvant radiation therapy, and abdomino-perineal resection are independent risk factors for sexual dysfunction. Pharmacotherapy with sildenafil has proven useful in the treatment of erectile disorders. Genito-urinary and ano-rectal sequelae occur concomitantly in more than one of ten patients, suggesting a potential common pathophysiology.

[Intraoperative pitfalls and complications in defecation disorders and rectal prolapse]

BACKGROUND

No generally accepted gold standard exists for the operative therapy of rectal prolapse in its variety of manifestations. Existing evidence suggests that an individualized choice of procedure provides the best result for each single patient. Knowledge of possible pitfalls and intraoperative management of complications in frequently applied procedures are important prerequisites for reliable treatment of affected patients.

MATERIAL AND METHODS

A consecutive series of 233 patients (June 2011-May 2016) with individualized choice of operative procedure in patients with rectal prolapse and rectocele based on an algorithm for a clinical treatment pathway and stapled hemorrhoidopexy were included. Intraoperative pitfalls and complications and their management (iPCM) were prospectively documented and analyzed.

RESULTS

The iPCM could be classified into three different categories: group I: iPCM was immediately noted and intraoperatively treated with no impact on the further clinical course (n = 20), group II: iPCM was successfully treated conservatively within a short time after the procedure (n = 9) and group III: iPCM required surgical revision (n = 5).

CONCLUSION

Individualized treatment of rectal prolapse and rectocele requires a broad spectrum of methods in specialized coloproctology units. A clinical treatment pathway facilitates the optimal choice of procedure. Overall the complication rates during surgical treatment of transanal rectal prolapse are low; however, available operative procedures hold specific risks and knowledge of these risks helps to avoid them. Once complications occur, measures demonstrated in this study lead to normal clinical courses in the majority of cases.

Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring

Finite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

Best practice: surgeon driven application in pelvic operations

In applied biomedical engineering and medical industry the transfer of established technology towards customers’ needs is essential for successful development and therefore business opportunities. In chronological order, we can show the transfer of scientific results of neurophysiological research into an existing neuromonitoring system and product which can be used by non-experts in medical technology in the operating room environment. All neurophysiology functions were realized in an intuitive graphical user interface. To stimulate the autonomous nerves, a specialized parameter paradigm was used, different from motor nerve stimulation. In the background, a complex signal processing algorithm recorded smooth muscle and bladder manometry data in synchronized time and automatically detected neurophysiological signals. The acquired data was then presented in real-time. With this effort a complex scientific task could be simplified to a Yes/No statement to the end-user. Beside all the reduction of complexity, the scientific challenge was still obtained, as raw-data is still possible to be recorded.

Continuous intraoperative monitoring of pelvic autonomic nerves during TME to prevent urogenital and anorectal dysfunction in rectal cancer patients (NEUROS): a randomized controlled trial

Background

Urinary, sexual and anorectal sequelae are frequent after rectal cancer surgery and were found to be related to intraoperative neurogenic impairment. Neuromonitoring methods have been developed to identify and preserve the complex pelvic autonomic nervous system in order to maintain patients’ quality of life. So far no randomized study has been published dealing with the role of neuromonitoring in rectal cancer surgery.

Methods/design

NEUROS is a prospective two-arm randomized controlled multicenter clinical trial comparing the functional outcome in rectal cancer patients undergoing total mesorectal excision (TME) with and without pelvic intraoperative neuromonitoring (pIONM). A total of 188 patients will be included. Primary endpoint is the urinary function measured by the International Prostate Symptom Score. Secondary endpoints consist of sexual, anorectal functional outcome and safety, especially oncologic safety and quality of TME. Sexual function is assessed in females with the Female Sexual Function Index and in males with the International Index of Erectile Function. For evaluation of anorectal function the Wexner-Vaizey score is used. Functional evaluation is scheduled before radiochemotherapy (if applicable), preoperatively (baseline), before hospital discharge, 3 and 6 months after stoma closure and 12 months after surgery. For assessment of safety adverse events, the rates of positive resection margins and quality of mesorectum are documented.

Discussion

This study will provide high quality evidence on the efficacy of pIONM aiming for improvement of functional outcome in rectal cancer patients undergoing TME.

Trial registration

Clinicaltrials.gov: NCT01585727. Registration date is 04/25/2012

The functional results of radical rectal cancer surgery: review of the literature

Introduction For more than the last 20 years, low anterior resection with total mesorectal excision (TME) is a gold standard for rectal cancer treatment. Oncological outcomes have improved significantly and now more and more reports of functional outcomes appear. Due to the close relationship between the rectum and pelvic nerves, bowel, bladder, and sexual function are frequently affected during TME. Methods A search for published data was performed using the MEDLINE database (from 1 January 2005 to 31 January 2015) to perform a systematic review of the studies that described anorectal, bladder, and sexual dysfunction following rectal cancer surgery. Methodological quality of the included studies was assessed using the MINORS criteria. Results Eighty-nine studies were eligible for analysis. Up to 76% of patients undergoing sphincter preserving surgery will have changes in bowel habits, the so-called "low anterior resection syndrome" (LARS). The duration of LARS varies between a few months and several years. Pre-operative radiotherapy, damage of anal sphincter and pelvic nerves, and height of the anastomosis are the risk factors for LARS. There is no evidence-based treatment available for LARS. Sexual function is more commonly affected after rectal surgery than after urinary function. The main cause of dysfunction is damage to pelvic nerves. Sexual and bladder functional outcomes in females are less well reported. Laparoscopic and robotic surgery allows better visualization of autonomic nerves and, therefore, more precise dissection and preservation. Conclusions It is important that rectal resection is standardized as much as possible, and that new functional outcome research use the same validated outcome questionnaires. This would allow for a high-quality meta-analysis.

Pelvic intraoperative neuromonitoring during robotic-assisted low anterior resection for rectal cancer

While the oncological outcome of patients with rectal cancer has been considerably improved within the last decades, anorectal, urinary and sexual functions remained impaired at high levels, regardless of whether radical surgery was performed open or laparoscopically. Consequently, intraoperative monitoring of the autonomic pelvic nerves with simultaneous electromyography of the internal anal sphincter and manometry of the urinary bladder has been introduced to advance nerve-sparing surgery and to improve functional outcome. Initial results suggested that pelvic neuromonitoring may result in better functional outcomes. Very recently, it has also been demonstrated that minimally invasive neuromonitoring is technically feasible. Because, to the best of our knowledge, pelvic neuromonitoring has not been performed during robotic surgery, we report the first case of robotic-assisted low anterior rectal resection combined with intraoperative monitoring of the autonomic pelvic nerves.

Lower urinary tract dysfunction in patients with peripheral nervous system lesions

The prevalence of lower urinary tract (LUT) dysfunction in peripheral nervous system (PNS) disorders is larger than in comparable control populations. This is particularly true for polyneuropathies with autonomic nervous system involvement, and for localized lesions with LUT innervation. LUT symptoms may be the guide to the diagnosis of processes localized in the lumbosacral spinal canal (as in cauda equina syndrome), and in the pelvis. Typical LUT dysfunctions (LUTD) caused by PNS involvement include bladder and sphincter hypoactivity with poor emptying, and incontinence. Paradoxically, bladder overactivity may also occur in pure PNS lesions. The acute cauda equina syndrome is an emergency requiring magnetic resonance imaging and surgery; in chronic neurogenic LUTD due to PNS involvement, the diagnosis of the lesion may be clarified by clinical neurophysiologic testing. Other important causes of neurogenic LUT dysfunction are perineoabdominal and pelvic surgeries. Surgeons are devising nerve-sparing techniques to prevent such major and often persistent complications in patients who are otherwise cured of the underlying disease. LUTD significantly affects the quality of life in patients and may lead to recurring urinary infections and upper urinary tract involvement. Thorough assessment of LUT function by urodynamics may be necessary in patients who are not improved by simple conservative measures.

Sexual dysfunction in patients with peripheral nervous system lesions

Peripheral nervous system (PNS) disorders may cause sexual dysfunction (SD) in patients of both genders. These disorders include mainly polyneuropathies (particularly those affecting the autonomic nervous system (ANS)) and localized lesions affecting the innervation of genital organs. Impaired neural control may produce a malfunction of the genital response consisting of loss of genital sensitivity, erectile dysfunction, loss of vaginal lubrication, ejaculation disorder, and orgasmic disorder. In addition, there is often a loss of desire which actually has a complex pathogenesis, which goes beyond the mere loss of relevant nerve function. In patients who have no manifest health problems - particularly men with erectile dysfunction - one should always consider the possibility of an underlying polyneuropathy; in patients with SD after suspected denervation lesions of the innervation of genital organs within the lumbosacral spinal canal and in the pelvis, clinical neurophysiologic testing may clarify the PNS involvement. SD can alter self-esteem and lower patients' quality of life; opening up a discussion on sexual issues should be a part of the management of patients with PNS disorders. They may greatly benefit from counseling, education on coping strategies, and specific treatments.

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.