The efficacy of a nerve stimulator (CaverMap) to enhance autonomic nerve identification and confirm nerve preservation during total mesorectal excision

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.

Rectal Sparing Approach After Neoadjuvant Therapy in Patients with Rectal Cancer: The Preliminary Results of the ReSARCh Trial

BACKGROUND

Rectum-preservation for locally advanced rectal cancer has been proposed as an alternative to total mesorectal excision (TME) in patients with major (mCR) or complete clinical response (cCR) after neoadjuvant therapy. The purpose of this study was to report on the short-term outcomes of ReSARCh (Rectal Sparing Approach after preoperative Radio- and/or Chemotherapy) trial, which is a prospective, multicenter, observational trial that investigated the role of transanal local excision (LE) and watch-and-wait (WW) as integrated approaches after neoadjuvant therapy for rectal cancer.

METHODS

Patients with mid-low rectal cancer who achieved mCR or cCR after neoadjuvant therapy and were fit for major surgery were enrolled. Clinical response was evaluated at 8 and 12 weeks after completion of chemoradiotherapy. Treatment approach, incidence, and reasons for subsequent TME were recorded.

RESULTS

From 2016 to 2019, 160 patients were enrolled; mCR or cCR at 12 weeks was achieved in 64 and 96 of patients, respectively. Overall, 98 patients were managed with LE and 62 with WW. In the LE group, Clavien-Dindo 3+ complications occurred in three patients. The rate of cCR increased from 8- to 12-week restaging. Thirty-three (94.3%) of 35 patients with cCR had ypT0-1 tumor. At a median 24 months follow-up, a tumor regrowth was found in 15 (24.2%) patients undergoing WW.

CONCLUSIONS

LE for patients achieving cCR or mCR is safe. A 12-week interval from chemoradiotherapy completion to LE is correlated with an increased cCR rate. The risk of ypT > is reduced when LE is performed after cCR.

A Prospective Analysis of the Effects of Nerve-Sparing Radical Prostatectomy on Urinary Continence Based on Expanded Prostate Cancer Index Composite and International Index of Erectile Function Scoring Systems

PURPOSE

This study aims to objectively characterize the effect of successful nerve sparing (NS) during radical prostatectomy (RP) on postoperative urinary continence (UC) using International Index of Erectile Function (IIEF)-scores and a previously described Expanded Prostate Cancer Index Composite (EPIC) score cutoff value (COV) for UC. Several notable studies on this topic present conflicting outcomes. This is largely due to a lack of clear definitions and consensus regarding preserved erectile function (EF) and UC.

METHODS

This study is comprised of all patients who underwent RP at the Kantonsspital Baden, Switzerland, between 2004 and 2013. Patients completed self-assessment questionnaires for UC (EPIC) and EF (IIEF) pre- and postoperatively (3, 6, 9, 12, 18, and 24 months; yearly thereafter). We used a previously described EPIC subscore COV, with "satisfactory continence" signified by a score >85. Statistical analysis was performed using Kaplan-Meier and Cox regression analyses for "surgeon-" and "IIEF-defined" NS definitions.

RESULTS

Of 236 men with a median age of 63 years (interquartile range [IQR], 59-66 years) and median follow-up time of 48 months (IQR, 30-78 months), 176 underwent unilateral (n=33) or bilateral (n=143) NS RP. Fifty-four underwent non-NS (NNS) RP. Kaplan-Meier analyses identified the following risk factors for UC: age, prostate volume, cancer risk group, and NS status. In surgeon-defined NS RP cases, multivariate analysis for regaining continence demonstrated no significant difference (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.48-1.25; P=0.3). With successful IIEF-defined NS RPs, regression analysis demonstrated no significant difference (HR, 0.89; 95% CI, 0.59-1.35; P=0.58).

Conclusions

In our population, analysis and comparison of surgeon- and IIEF-defined NS and NNS cohorts revealed that NS RP did not improve postoperative UC. The conservation of UC alone should not motivate surgeons or patients to pursue NS RP.

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.

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.

Evaluation of two-dimensional intraoperative neuromonitoring for predicting urinary and anorectal function after rectal cancer surgery

PURPOSE

The aim of this study was to compare the results of two-dimensional intraoperative neuromonitoring (IONM) with the postoperative urinary and anorectal function of rectal cancer patients.

METHODS

A consecutive series of 35 patients undergoing low anterior resection were investigated prospectively. IONM was performed with electric stimulations of the pelvic splanchnic nerves under simultaneous manometry of the bladder and electromyography (EMG) of the internal anal sphincter (IAS). Urinary and anorectal function were evaluated preoperatively and at follow-up by standardized questionnaires, digital rectal examination scoring system, and long-term catheterization rate.

RESULTS

The rate of postoperative newly developed bladder dysfunction was 17 %. IONM with bladder manometry had a sensitivity of 100 %, specificity of 96 %, positive predictive value of 83 %, negative predictive value of 100 %, and overall accuracy of 97 %, respectively. The proportion of patients with severely impaired anorectal function at follow-up was 8 %. The sensitivity, specificity, and positive and negative predictive values for IONM with EMG of the IAS were, respectively, 100, 96, 67, and 100 % with an accuracy of 96 %. The degree of agreement for IONM with EMG of the IAS was good for anorectal function (к = 0.780) and poor for urinary function (к = 0.119). IONM with bladder manometry yielded a very good degree of agreement for urinary function (к = 0.891) and a fair agreement for anorectal function (к = 0.336).

CONCLUSIONS

The two-dimensional IONM method is suitable for verification of bladder and IAS innervation. Accurate prediction of urinary and anorectal function necessitates both bladder manometry and EMG of the IAS.

Risk factors for sexual dysfunction after rectal cancer treatment

This study aimed to identify risk factors for long-term sexual dysfunction (SD) after rectal cancer treatment. Patients with resectable rectal cancer were randomised to total mesorectal excision with or without preoperative radiotherapy (PRT). Preoperatively and at 3, 6, 12, 18 and 24 months postoperatively, SD scores were filled out in questionnaires. Possible risk factors for postoperative deterioration of sexual functioning, including patients' demographics, tumour-specific factors and treatment-related variables, were investigated with univariate and multivariable regression analyses. Increase in general SD, erectile dysfunction and ejaculatory problems were reported by 76.4, 79.8 and 72.2 percent of the male patients, respectively. Risk factors were nerve damage, blood loss, anastomotic leakage, PRT and the presence of a stoma. In female patients, increase in general SD, dyspareunia and vaginal dryness were reported by 61.5, 59.1 and 56.6 percent, respectively. This was associated with PRT and the presence of a stoma. SD occurs frequently after rectal cancer treatment and is caused by surgical (nerve) damage with an additional effect of PRT. Patients should be informed preoperatively, and education of surgeons in neuroanatomy may provide the key to the improvement of functional outcome.

Faecal and urinary incontinence after multimodality treatment of rectal cancer

Marilyne Lange and Cornelis van de Velde discuss the differential diagnosis and management of incontinence after rectal cancer treatment.

Urinary dysfunction after rectal cancer treatment is mainly caused by surgery

BACKGROUND

Urinary dysfunction (UD) is common after rectal cancer treatment, but the contribution of each treatment component (surgery and radiotherapy) to its development remains unclear. This study aimed to evaluate UD during 5 years after total mesorectal excision (TME) and to investigate the influence of preoperative radiotherapy (PRT) and surgical factors.

METHODS

Patients with operable rectal cancer were randomized to TME with or without PRT. Questionnaires concerning UD were completed by 785 patients before and at several time points after surgery. Possible risk factors, including PRT, demographics, tumour location, and type and extent of resection, were investigated by multivariable regression analysis.

RESULTS

Long-term incontinence was reported by 38.1 per cent of patients, of whom 72.0 per cent had normal preoperative function. Preoperative incontinence (relative risk (RR) 2.75, P = 0.001) and female sex (RR 2.77, P < 0.001) were independent risk factors. Long-term difficulty in bladder emptying was reported by 30.6 per cent of patients, of whom 65.0 per cent had normal preoperative function. Preoperative difficulty in bladder emptying (RR 2.94, P < 0.001), peroperative blood loss (RR 1.73, P = 0.028) and autonomic nerve damage (RR 2.82, P = 0.024) were independent risk factors. PRT was not associated with UD.

CONCLUSION

UD is a significant clinical problem after rectal cancer treatment and is not related to PRT, but rather to surgical nerve damage.

Evidence and research in rectal cancer

The main evidences of epidemiology, diagnostic imaging, pathology, surgery, radiotherapy, chemotherapy and follow-up are reviewed to optimize the routine treatment of rectal cancer according to a multidisciplinary approach. This paper reports on the knowledge shared between different specialists involved in the design and management of the multidisciplinary ESTRO Teaching Course on Rectal Cancer. The scenario of ongoing research is also addressed. In this time of changing treatments, it clearly appears that a common standard for large heterogeneous patient groups have to be substituted by more individualised therapies based on clinical-pathological features and very soon on molecular and genetic markers. Only trained multidisciplinary teams can face this new challenge and tailor the treatments according to the best scientific evidence for each patient.

Long-term urinary dysfunction after mesorectal excision: A prospective study with intraoperative electrophysiological confirmation of nerve preservation

BACKGROUND

Bladder dysfunctions are well-recognized complications after nerve-sparing mesorectal excision for rectal cancer. This study sought to symptomatically analyze the extent of recovery from major and minor urinary symptoms in patients with signs of bladder denervation.

METHODS

Sixty-two patients with mesorectal excision for rectal cancer were investigated prospectively. Pelvic autonomic nerve preservation (PANP) was assessed macroscopically and with the aid of intraoperative electrical stimulation of pelvic autonomic nerves (INS). Bladder function was evaluated with the International Prostate Symptom Score (IPSS) and the Quality of life index (Qol). Median follow-up was 20 months (range 3-40 months).

RESULTS

Forty-six patients with INS-confirmed preservation of parasympathetic nerves remained unchanged in early and long-term urinary function (IPSS: median 1; range 0-24 and Qol 0; range 0-5). In 15 patients without confirmation of PANP (unilaterally or bilaterally) on INS, voiding function was significantly more impaired postoperatively (IPSS: median 10; range 0-25 and Qol 3; range 0-6) and at long-term follow-up (IPSS: median 9; range 0-25 and Qol 3; range 0-6) (p<0.001). Voiding function was improved in 4 of 10 patients with major and minor symptoms. In 5 of 6 patients with long-term bladder dysfunction INS assessed parasympathetic nerve damage unilaterally (3/5) and bilaterally (2/5).

CONCLUSION

Long-term voiding disturbance after mesorectal excision was found to be a serious complication. INS while monitoring intravesical pressure is a valuable aid in predicting long-term bladder function after TME. The device may serve a secondary preventive function in enabling the initiation of early urologic therapy.

Ileal pouch-anal anastomosis

BACKGROUND

Since 1977, restorative proctocolectomy with ileoanal anastomosis (IAA) has evolved into the surgical treatment of choice for most patients with intractable ulcerative colitis. Construction of an ileal pouch reservoir is now standard, usually in the form of J pouch (IPAA). The aim of this report is to review selection criteria for, and functional outcomes, follow-up and management of complications of IPAA after 30 years of widespread clinical application.

METHODS AND RESULTS

Literature published in English on the clinical indications, surgical technique, morbidity, complications and outcome following IAA and IPAA was sourced by electronic search, performed independently by two reviewers who selected potentially relevant papers based on title and abstract. Additional articles were identified by cross-referencing from papers retrieved in the initial search.

CONCLUSION

The functional results of IPAA are good. Pouchitis, irritable pouch syndrome and cuffitis are specific long-term complications but rarely result in failure. Pouch salvage is possible in selected patients with poor functional outcomes. One-stage operations are increasingly performed.

Intraoperative electrostimulation objectifies the assessment of functional nerve preservation after mesorectal excision

BACKGROUND

To improve nerve-sparing surgery, intraoperative electrical stimulation of pelvic autonomic nerves (INS) has been proposed in urology, gynecology, and visceral surgery. The aim of this study was to assess the impact of INS while monitoring intravesical pressure on the accurate evaluation of pelvic autonomic nerve preservation (PANP) after mesorectal excision. It was sought to determine whether this confirmation is useful in the prediction of postoperative urinary function.

METHODS

Sixty-two patients with mesorectal exzision for rectal cancer were examined prospectively. PANP was assessed visually by the surgeon and with INS. Bladder function was evaluated by post voiding residual volume measurement, rate of recatheterization, rate of long-term urinary catheterisation, and the international prostatic symptom score with quality of life index.

RESULTS

INS confirmed bilateral preservation of parasympathetic nerves in 46 patients (74%), and in 10 patients (16%) in at least one side. In six patients (10%), INS failed to confirm PANP. Eleven patients (18%) developed urinary symptoms postoperatively. INS results had a higher sensitivity than visual assessment by the surgeon (82 vs 46%). Values for specificity ranged at 90 and 92%, respectively. Accuracy of INS in predicting PANP was higher (88 vs 83%). The correlation between urinary function and the findings on INS was good (kappa-value: 0.65), correlation between urinary function and visual assessment by the surgeon was fair (kappa-value: 0.40).

CONCLUSION

INS, while monitoring intravesical pressure, accurately predicts bladder function after mesorectal excision. It may provide further insight into pelvic autonomic nerve sparing techniques.

Male Urogenital Function After Confirmed Nerve-Sparing Total Mesorectal Excision with Dissection in Front of Denonvilliers’ Fascia

This prospective study addresses the rate of male genital dysfunction following total mesorectal excision (TME) for rectal carcinoma using the anterior extramesorectal plane and its correlation with early urinary function, pelvic autonomic nerve preservation (PANP), and intraoperative neurostimulation (INS). A consecutive series of 44 men operated on by the same surgical team was analyzed. After excluding 18 patients considered to be impotent preoperatively, urogenital function was evaluated in 26 patients on the basis of the International Prostatic Symptom Score and International Index of Erectile Function. PANP was assessed with INS of parasympathetic nerves. PANP was complete in 21 patients (80.8%). Deterioration of urinary function was observed in six patients (23.1%) at early follow-up. Postoperative erectile dysfunction assessed in seven patients (26.9%) was associated with micturition disturbances in four (57%). Despite dissection in front of Denonvilliers fascia, the incidence of erectile dysfunction was low in patients with nonanterior tumors (1/10). INS results had higher sensitivity for predicting urinary dysfunction than for predicting erectile dysfunction (67% vs. 43%). Values for specificity and accuracy were 95% and 90%, and 89% and 77%, respectively. The correlation between the findings on INS and urinary function was good (kappa = 0.66) at a fair (kappa = 0.36) correlation for erectile function. Nerve-sparing TME using the anterior extramesorectal plane results in a justifiable rate of postoperative impotence in patients with nonanterior tumors. Patients with negative results on INS or early urinary dysfunction are at greater risk of erectile dysfunction.

Reconstruction of cavernous nerves by nerve grafts to restore potency: contemporary review of technical principles and basic anatomy

PURPOSE OF REVIEW

The review discusses the efficacy of reconstructing the neurovascular bundle to regain sexual function if nerve-sparing prostatectomy is unfeasible.

RECENT FINDINGS

Eleven studies could be found describing the reconstruction of neurovascular bundles. All reconstructive procedures displayed technical inadequacies. The effectiveness of unilateral neurovascular bundle reconstruction remains statistically insignificant when compared with procedures without reconstruction. The efficacy of reconstructing both neurovascular bundles ranges between 0 and 43%. Concerning basic anatomy, the neurovascular bundle contains fibers innervating the cavernous nerves, prostate, rectum, and levator ani muscle. The terms cavernous nerve and neurovascular bundle have often been wrongly considered synonymous. The pelvic splanchnic nerves probably do not join the neurovascular bundle proximal to the bladder/prostate junction but rather at variable distances from 10 to 20 mm distal to it. Therefore, described proximal coaptation sites at the bladder/prostate junction possibly encompass only the hypogastric nerve.

SUMMARY

Modest clinical results are partly due to inadequate surgical techniques and are mainly due to the anatomical and topographical complexity of the cavernous nerves. Contemporary nerve grafting techniques probably do not allow for the regeneration of all cavernous nerves.

Preservation of the Marginal Mandibular Branch of the Facial Nerve Using a Plexus Block Nerve Stimulator

Preserving the marginal mandibular branch of the facial nerve is essential in submandibular neck dissection to avert disfiguring complications. Despite the high incidence of postoperative palsy, old-fashioned techniques of nerve identification remain widespread. The use of disposable plexus block nerve stimulators as a safe and accurate method to localize the nerve intraoperatively is suggested herein. Such devices are significantly more affordable and user-friendly than larger facial nerve monitoring devices, which are rather favored for those procedures more extensively jeopardizing the branches of the facial nerve. In this report, disposable stimulators led to successful identification of the nerve in 100% of 25 patients between 2003 and 2005, with no postoperative paralysis. In addition, stimulation devices are constantly gaining in reliability and safety, and the number of surgical fields supporting their use is expanding. Therefore, their routine use for surgery on the submandibular area is recommended by the authors.

Impact of functional results on quality of life after rectal cancer surgery

PURPOSE

Quality of life is an important outcome measure that has to be considered when deciding treatment strategy for rectal cancer. The aim of this study was to find out the impact of surgery-related adverse effects on quality of life.

METHODS

The RAND-36 questionnaire and questionnaires assessing urinary, sexual, and bowel dysfunction were administered to 94 patients with no sign of recurrence a minimum of one year after curative surgery. Results were compared with age-matched and gender-matched general population.

RESULTS

Eighty-two (87 percent) patients answered the questionnaires. Major bowel dysfunction was as common after high anterior resection as after low anterior resection. Urinary complaints occurred as often after anterior resection as after abdominoperineal resection, but sexual dysfunction was more common after abdominoperineal resection. Overall, the patients reported better general health perception but poorer social functioning than population controls. In particular, elderly patients reported a significantly better quality of life in many dimensions than their population controls. There was no significant difference in quality of life between treatment groups. Major bowel dysfunction after anterior resection impaired social functioning compared with that of patients without such symptoms. Urinary dysfunction impaired social functioning and impotence impaired physical and social functioning.

CONCLUSIONS

Quality of life after rectal cancer surgery is not worse than that of the general population. The major adverse impact of bowel and urogenital dysfunction is on social functioning. These adverse effects need to be discussed with the patient and preoperative function needs to be taken into account when choosing between treatment options. Permanent colostomy is not always the factor that disrupts a person's quality of life most.

Recent neuroanatomical studies on the neurovascular bundle of the prostate and cavernosal nerves: clinical reflections on radical prostatectomy

The neurovascular bundle of the prostate and cavernosal nerves have been used to describe the same structure ever since the publication of the first studies on the neuroanatomy of the lower urogenital tract of men, studies that were prompted by postoperative complications arising from radical prostatectomy. In urological surgery every effort is made to preserve or restore the neurovascular bundle of the prostate to avoid erectile dysfunction (ED). However, the postoperative potency rates are yet to be satisfactory despite all advancements in radical prostatectomy technique. As the technology associated with urological surgery develops and topographical studies on neuroanatomy are cultivated, new observations seriously challenge the classical teachings on the topography of the neurovascular bundle of the prostate and the cavernosal nerves. The present review revisits the classical and most recent data on the topographical anatomy of the neurovascular bundle of the prostate and cavernosal nerves and their implications on radical prostatectomy techniques.