LARS is a significant problem found in about one third of rectal cancer patients after colorectal anastomosis. Symptoms of concern include pain on defecation and decreased ability to hold. Risk of having major LARS increases with adjuvant treatment and lower anastomotic level.
Background/Aim Brain-gut dysfunction has been implicated in gastrointestinal disorders but a comprehensive test of brain-gut axis is lacking. We developed and tested a novel method for assessing both afferent anorectal-brain function using cortical evoked potentials (CEP), and efferent brain-anorectal function using motor evoked potentials (MEP). Methods CEP was assessed following electrical stimulations of anus and rectum with bipolar electrodes in 26 healthy subjects. Anorectal MEPs were recorded following transcranial magnetic stimulation (TMS) over paramedian motor cortices bilaterally. Anal and rectal latencies/amplitudes for CEP and MEP responses and thresholds for first sensation and pain (mA) were analyzed and compared. Reproducibility and interobserver agreement of responses were examined. Results Reproducible polyphasic rectal and anal CEPs were recorded in all subjects, without gender differences, and with negative correlation between BMI and CEP amplitude (r −0.66, p=0.001). TMS evoked triphasic rectal and anal MEPs, without gender differences. Reproducibility for CEP and MEP was excellent (CV <10%). The inter-rater CV for anal and rectal MEPs was excellent (ICC 97–99), although there was inter-subject variation. Conclusions Combined CEP and MEP studies offer a simple, inexpensive and valid method of examining bidirectional brain-anorectal axes. This comprehensive method could provide mechanistic insights into lower gut disorders.
Background Neurological dysfunction causes fecal incontinence, but current techniques for its assessment are limited and controversial. Objective To investigate spino-rectal and spino-anal motor evoked potentials simultaneously using lumbar and sacral magnetic stimulation in fecal incontinence and healthy subjects, and to compare motor evoked potentials and pudendal nerve terminal motor latency in fecal incontinence subjects. Design Prospective observational study. Settings Two Tertiary Care Centers. Patients Adult fecal incontinence and healthy subjects. Interventions Translumbar and transsacral magnetic stimulations performed bilaterally by applying a magnetic coil to the lumbar and sacral regions in 50 fecal incontinence (≥ 1 episode/week) and 20 healthy subjects. Both motor evoked potentials and pudendal nerve terminal motor latency were assessed in 30 fecal incontinence patients. Stimulation-induced motor evoked potentials were recorded simultaneously from rectum and anus with two pairs of bipolar ring electrodes. Main Outcome Measurements Latency and amplitude of motor evoked potentials after lumbosacral magnetic stimulation and agreement with pudendal nerve terminal motor latency. Results When compared to controls, one or more lumbo-anal, lumbo-rectal, sacro-anal, or sacro-rectal motor evoked potentials were significantly prolonged (p<0.01) and were abnormal in 44/50 (88%) fecal incontinence subjects. Positive agreement between abnormal motor evoked potentials and pudendal nerve terminal motor latency was 63% whereas negative agreement was 13%. motor evoked potentials were abnormal in more (p <0.05) fecal incontinence patients than pudendal nerve terminal motor latency, 26/30 (87%) versus 19/30 (63%) respectively, and in 24% of patients with normal pudendal nerve terminal motor latency. No adverse events. Limitations Anal electromyography was not performed. Conclusions Translumbar and transsacral magnetic stimulation–induced motor evoked potentials provide objective evidence for rectal or anal neuropathy in fecal incontinence patients and could be useful. Test was superior to pudendal nerve terminal motor latency and appears to be safe and well tolerated.
With the limitation of sample size in this study, there was a trend to improve PPE incidence and time to event with a higher dose of pyridoxine. Further validation of these results in a larger population is warranted.
Introduction Spinal cord injury (SCI) causes anorectal problems, whose pathophysiology remains poorly characterized. A comprehensive method of evaluating spino-anorectal function is lacking. Aim To investigate the neuropathophysiology of bowel dysfunction in SCI by evaluating motor evoked potentials (MEP) of anus and rectum following trans-spinal magnetic stimulation and anorectal physiology. Methods Translumbar and transsacral magnetic stimulations, anorectal manometry and pudendal nerve latency (PNTML) were performed in 39 subjects with SCI and anorectal problems and 14 healthy controls and data were compared. MEPs were recorded with an anorectal probe containing bipolar ring electrodes. Results The MEPs were significantly prolonged (p<0.05) bilaterally, and at lumbar and sacral levels, and at rectal and anal sites in SCI subjects compared to controls. 95% of SCI subjects had abnormal MEPs; 53% had abnormal PNTML. All subjects with abnormal PNTML also demonstrated abnormal MEP, but 16/17 subjects with normal PNTML had abnormal MEP. Overall SCI patients had weaker anal sphincters (p<0.05), higher prevalence of dyssynergia (85%) and altered rectal sensation (82%). Conclusions Translumbar and transsacral MEPs revealed significant and hitherto undetected lumbo-sacral neuropathy in 90% of SCI subjects. Test was safe and provided neuropathophysiological information that could explain bowel dysfunction in SCI subjects.
ObjectiveEndoanal ultrasound (EAUS) is a recommended preoperative investigation for fistula-in-ano (FiA) which aims to provide the best chance of healing and preservation of continence function. This study aims are (1) to assess effect of EAUS on functional outcome and (2) to determine factors associated with clinical outcomes after FiA surgery.DesignRetrospective analysis of subjects with cryptogenic FiA between January 2011 and December 2016, in a tertiary hospital, was performed by comparing EAUS and no-EAUS groups. Postoperative change in St. Mark’s faecal incontinence severity score (cFISS=FISS at 6 months after surgery–FISS before surgery) were compared. General linear model was used to determine factors associated with cFISS. Binary logistic regression was used to assess factors related to clinical outcomes. A p-value of <0.05 is considered significant.Results We enrolled 339 subjects; 109 (M:F 91:18, mean age 41.7±13.6 years) of 115 in EAUS group and 230 in no-EAUS group (M:F 195:35, mean age 42.6±13.0 years). There were higher proportions of recurrent cases (24.8% vs 13.9%, p=0.014) and complex FiA (80.7% vs 50.4%, p=0.001) in EAUS group. Postoperative FISS (mean±SE) were increased in both groups; preoperative versus postoperative FISS were 0.36±0.20 versus 0.59±0.25 in EAUS group (p=0.056) and 0.31±0.12 versus 0.76±0.17 in no-EAUS group (p<0.001). EAUS had significant effects on cFISS in both univariate analysis, F(1,261)=4.053, p=0.045; and multivariate analysis, F(3,322)=3.147, p=0.025, Wilk’s Lambda 0.972. Other associated factors included recurrent fistula (F(3,322)=0.777, p=0.007, Wilk’s Lambda 0.993) and fistula classification (F(3,322)=16.978, p<0.001, Wilk’s Lambda 0.863). After a mean follow-up of 33.6±28.6 weeks, success rate was 63.3%(EAUS) and 60% (no-EAUS), p=0.822. Factors associated with clinical outcomes were fistula complexity, number of tracts, recurrence, number of previous surgery and type of operations. Accuracy of EAUS was 90.8% and not related to clinical outcomes (p=0.522).ConclusionEAUS had favourable effects on functional outcome after FiA surgery while multiple factors were associated with clinical outcomes. EAUS is useful, accurate, inexpensive and can be the first tool for planning of complex and recurrent FiA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.