Fatigue rate index as a new measurement of external sphincter function

London Protocol under water-perfused HRM in a healthy population, towards novel 3D manometric parameters in an evaluation of anorectal functional disorders

BACKGROUND/AIM

London Protocol (LP) and Classification allied to high-resolution manometry (HRM) technological evolution has updated and enhanced the diagnostic armamentarium in anorectal disorders. This study aims to evaluate LP reproducibility under water-perfused HRM, provide normal data and new parameters based on 3D and healthy comparison studies under perfusional HRM.

METHODS

Fifty healthy (25 F) underwent water-perfused 36 channel HRM based on LP at resting, squeeze, cough, push, and rectal sensory. Additional 3D manometric parameters were: pressure-volume (PV) 104mmHg2.cm (resting, short and long squeeze, cough); highest and lowest pressure asymmetry (resting, short squeeze, and cough). Complementary parameters (CP) were: resting (mean pressure, functional anal canal length); short squeeze (mean and maximum absolute squeeze pressure), endurance (fatigue rate, fatigue rate index, capacity to sustain); cough (anorectal gradient pressure); push (rectum-anal gradient pressure, anal canal relaxation percent); recto-anal inhibitory reflex (anal canal relaxation percent).

RESULTS

No difference to genders: resting (LP, CP, and 3D); short squeeze (highest pressure asymmetry); endurance (CP); cough (CP, highest and lowest pressure asymmetry); push (gradient pressure); rectal sensory. Higher pressure in men: short squeeze (maximum incremental, absolute, and mean pressure, PV, lowest pressure asymmetry); long squeeze (PV); cough (anal canal and rectum maximum pressure, anal canal PV); push (anal canal and rectum maximum pressure). Anal canal relaxation was higher in women (push).

CONCLUSIONS

LP reproducibility is feasible under water-perfused HRM, and comparative studies could bring similarity to dataset expansion. Novel 3D parameters need further studies with healthy and larger data to be validated and for disease comparisons.

KEY POINTS

• London Protocol and Classification allied with the technological evolution of HRM (software and probes) has refined the diagnostic armamentarium in anorectal disorders. • Novel 3D and deepening the analysis of manometric parameters before the London Classification as a contributory diagnostic tool. • Comparison of healthy volunteers according to the London Protocol under a perfusional high-resolution system could establish equivalence points.

Optimizing techniques for measuring anal resting and squeeze pressures with high-resolution manometry

BACKGROUND

The optimal methods for measuring and analyzing anal resting and squeeze pressure with high-resolution manometry (HRM) are unclear.

METHODS

Anal resting and squeeze pressures were measured with HRM in 90 healthy women, 35 women with defecatory disorders (DD), and 85 with fecal incontinence (FI). Pressures were analyzed with Manoview™ software and a customized approach. Resting pressures measured for 20, 60, and 300 s were compared. During the squeeze period, (3 maneuvers, 20 s each), the squeeze increment, which was averaged over 5, 10, 15, and 20 s, and squeeze duration were evaluated.

RESULTS

Compared to healthy women, the anal resting pressure, squeeze pressure increment, and squeeze duration were lower in FI (p ≤ 0.04) but not in DD. The 20, 60, and 300 s resting pressures were strongly correlated (concordance correlation coefficients = 0.96-0.99) in healthy and DD women. The 5 s squeeze increment was the greatest; 10, 15, and 20 s values were progressively lower (p < 0.001). The squeeze pressure increment and duration differed (p < 0.01) among the three maneuvers in healthy and DD women but not in FI women. The upper 95th percentile limit for squeeze duration was 19.5 s in controls, 19.9 s in DD, and 19.3 s in FI. Adjusted for age, resting pressure, and squeeze duration, a greater squeeze increment was associated with a lower risk of FI versus health (OR, 0.96; 95% CI, 0.94-0.97).

CONCLUSIONS

These findings suggest that anal resting and squeeze pressures can be accurately measured over 20 s. In most patients, one squeeze maneuver is probably sufficient.

Anal sphincter fatigability in assessing anal incontinence: A systematic review

BACKGROUND

Diagnosing anal incontinence (AI) based on manometry results is challenging due to the variation of the normal values and overlap between patients with and without AI. This study aimed to perform a systematic review on the difference in sphincter fatigability between patients with and without AI.

METHODS

MEDLINE, EMBASE, SCOPUS, and Google Scholar were searched. Studies were included if they included adult patients and assessed anal sphincter fatigability between using manometry. The effect size was estimated as the standardized mean difference (SMD) with 95% confidence intervals. A random-effects model was used.

RESULTS

The database searches identified 125 unique articles, and five additional articles were identified from the reference list of articles. One hundred thirteen were excluded through title and abstract review. Nine articles were included in the final analysis. There was no statistically significant difference in the resting pressure between the two groups. Patients with AI had significantly lower squeeze pressure. There was no statistically significant difference between the groups in the fatigue rate. The FRI was significantly lower in patients with AI (SMD 1.636, p = 0.001). Approximately a third of the patients in one study were able to maintain a contraction for 20s without reducing pressure. There was significant heterogeneity in the studies. The data available were inadequate for more robust calculations.

CONCLUSIONS

Sphincter fatigability, measured by the Fatigability Rate Index, has good discriminating power for anal incontinence. A standardized protocol needs to be followed by future researchers. Graphical Abstract The analysis used six studies with 413 patients to compare Fatigue Rate Index between patients with AI and controls. All studies reported a lower FRI in patients with incontinence and the FRI was significantly lower in patients with AI (standardized mean difference [SMD] 1.636, p= 0.001). Conflicting results were reported on the correlation between FRI and AI symptom scores.

THE FATIGUE RATE INDEX IS HIGHER IN CHILDREN WITH FUNCTIONAL CONSTIPATION AND RETENTIVE FECAL INCONTINENCE

BACKGROUND

The Fatigue Rate Index (FRI) is a parameter in anorectal manometry (ARM) to assess sustained voluntary contraction, considering the squeeze pressure and fatigability of the external anal sphincter. It is used in adults to detect fecal incontinence even in patients who present normal squeeze pressures. The FRI in adult patients with functional constipation is similar to controls.

OBJECTIVE

The aim of this study was to evaluate the feasibility and values of FRI in children in relation to the values previously established in adults and comparing children with functional constipation and retentive fecal incontinence to children without retentive fecal incontinence.

METHODS

This retrospective study evaluated 105 ARM performed from Jan 2014 to Apr 2015. 42 patients were selected (were able to perform a voluntary contraction and had no co-morbidities other than functional constipation). 14 (33.3%) of those collaborated in sustaining contraction for 40 seconds (s), allowing the evaluation of the FRI. Patients with retentive fecal incontinence secondary to functional constipation (n=7, aged 6 to 13 years, six boys) were our interest group. Patients with functional constipation without fecal incontinence (n=7, aged 6 to 13 years, four boys) were considered a reference group. The ARM were performed with a radial eight-channel perfusion catheter (DynamedTM, São Paulo, Brazil) and the FRI was calculated (Proctomaster 6.4) in the first 20 s and overall 40 s of sustained voluntary contraction.

RESULTS

14 of the selected 42 collaborated in sustaining contraction for 40 s, allowing the evaluation of the FRI. In the first 20 s of contraction, the fecal incontinence group showed a significantly higher mean FRI (2.48±1.39 min) compared to the reference group (1.13±0.72 min, P=0.042), which was not observed in the 40 s interval due to less uniform contraction. The anal resting pressure was higher in the fecal incontinence group (76.83 mmHg) than in the reference group (54.13 mmHg), but the statistical study did not reach significance (P=0.051).

CONCLUSION

The FRI is feasible in children. The mean FRI obtained in this study is lower than the reported in constipated adults. The mean FRI among children with functional constipation and retentive fecal incontinence is higher than among constipated children without retentive fecal incontinence.

Fatigability of the external anal sphincter muscles using a novel strength training resistance exercise device

Exercises involving pelvic floor muscles including repetitive voluntary contractions of external anal sphincter (EAS) musculature have been used to improve fecal incontinence. Muscle fatigue is a prerequisite for successful strength training. However, muscle fatigue induced by these exercises has not been systematically studied. We aimed to assess the fatigability of EAS muscles during various exercise methods. Twelve nulliparous (21 ± 2.7 yr) women were studied. We evaluated fatigue during 40 repetitive 3-s contractions and 30-s long squeeze contractions both with and without an intra-anal compressible resistant load. The sequence of exercises was randomized. This load was provided by the continence muscles Resistance Exerciser Device. Anal canal pressures were recorded by high-resolution manometry. Exercise against a resistive load showed significant decrease in anal contractile integral (CI) and maximum squeeze pressure during repetitive short squeeze contractions compared with exercise without a load. Linear regression analysis showed a significant negative correlation between anal CI and successive contraction against load, suggesting "fatigue." Similar findings were observed for maximum squeeze pressure (slope with load = -4.2, P = 0.0003, vs. without load = -0.9, P = 0.3). Long squeeze contraction against a load was also more susceptible to fatigue than without a load (P < 0.0001). In conclusion, repetitive contractions against a compressible load induce fatigue and thus have the potential to strengthen the anal sphincter contractile function than contractions without a load. Fatigue rate in long squeeze contraction exercises with a load is significantly faster than that without a load, also indicating greater effectiveness in inducing muscle fatigue.NEW & NOTEWORTHY Fecal incontinence is a distressing disorder with a mainstay of treatment being pelvic floor muscle exercises. However, none of these exercises has proven occurrence of fatigability, which is an important prerequisite for successful muscle strengthening in rehabilitative exercises. In this study, we proved that we can fatigue the external anal sphincter muscles more efficiently by providing a resistive load during anal repetitive short squeeze contractions and long squeeze contraction exercise.

External Anal Sphincter Fatigability: An Electromyographic and Manometric Study in Patients With Anorectal Disorders

Background/Aims

External anal sphincter (EAS) plays an important role in fecal and gas voluntary continence. Like every muscle, it can be affected by repeated efforts due to fatigability (physiological response) and/or fatigue (pathological response). No standardized fatiguing protocol and measure method to assess EAS fatigability has existed. The aim is to test a simple, standardized protocol for fatiguing and measuring EAS fatigability and fatigue to understand better the part of EAS fatigability in the pathophysiology of fecal incontinence.

Methods

Patients with anorectal disorders evaluated with anorectal manometry were included. They had to perform 10 repetitions of maximum voluntary contraction (MVC) of 20 seconds. Measurement was made with an anorectal manometry catheter and a surface recording electromyography (EMG). The primary outcome was the difference in EMG root mean square between the first and the last MVC. Secondary outcomes were differences in other EMG and manometry parameters between the first and the last MVC. Difficulties and adverse effects were recorded.

Results

Nineteen patients underwent the fatiguing protocol. All patients completed the entire protocol and no complications were found. No difficulty was declared by the examiner. A significant decrease in root mean square was found between the first and last MVC (0.01020 ± 0.00834 mV vs 0.00661 ± 0.00587 mV; P = 0.002), in maximum anal pressure area under the curve of continuous recordings of anal pressure and mean and total EMG power (P < 0.05).

Conclusions

This protocol is simple and minimally invasive to measure EAS fatigue and fatigability. We highlighted a fatigue of EAS in many patients with anorectal disorders.

Pelvic floor rehabilitation for defecation disorders

Pelvic floor rehabilitation is frequently recommended for defecation disorders, in both constipation and fecal incontinence. However, the lack of patient selection, together with the variety of rehabilitation methods and protocols, often jeopardize the results of this approach, causing difficulty in evaluating outcomes and addressing proper management, and above all, in obtaining scientific evidence for the efficacy of these methods for specific indications. The authors represent different gastroenterological and surgical scientific societies in Italy, and their aim was to identify the indications and agree on treatment protocols for pelvic floor rehabilitation of patients with defecation disorders. This was achieved by means of a modified Delphi method, utilizing a working team (10 members) which developed the statements and a consensus group (15 members, different from the previous ones) which voted twice also suggesting modifications of the statements.

Review of pelvic and perineal neuromuscular fatigue: Evaluation and impact on therapeutic strategies

BACKGROUND

Pelvic floor fatigue is known by its clinical consequences (fecal incontinence, stress urinary incontinence, pelvic organ prolapse), but there are still few studies on the subject.

OBJECTIVE

This article presents an overview of the current knowledge of pelvic and perineal fatigue, focusing on its assessment and consequences in terms of evaluation and therapeutic strategies, to propose an evaluation that could be routinely performed.

METHODS

We performed a systematic review of the literature in MEDLINE via PubMed and Cochrane Library databases by using the keywords pelvic floor, muscular fatigue, physiopathology, stress urinary incontinence, pelvic organ prolapse, fecal incontinence, physical activity, and pelvic rehabilitation. We included reports of systematic reviews and retrospective and prospective studies on adult humans and animals in English or French published up to April 2018 with no restriction on start date.

RESULTS

We selected 59 articles by keyword search, 18 by hand-search and 3 specific guidelines (including the 2009 International Continence Society recommendations); finally 45 articles were included; 14 are described in the Results section (2 reviews of 6 and 20 studies, and 12 prospective observational or cross-over studies of 5 to 317 patients including 1 of animals). Perineal fatigue can be assessed by direct assessment, electromyography and spectral analysis and during urodynamics. Because pelvic floor fatigue assessments are not evaluated routinely, this fatigability is not always identified and is often falsely considered an exclusive pelvic floor weakness, as suggested by some rehabilitation methods that also weaken the pelvic floor instead of enhancing it.

CONCLUSION

Pelvic floor fatigue is not evaluated enough on a routine basis and the assessment is heterogeneous. A better knowledge of pelvic floor fatigue by standardized routine evaluation could lead to targeted therapeutic strategies.

Diagnosis and treatment of faecal incontinence: Consensus statement of the Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists

Faecal incontinence is a common and disturbing condition, which leads to impaired quality of life and huge social and economic costs. Although recent studies have identified novel diagnostic modalities and therapeutic options, the best diagnostic and therapeutic approach is not yet completely known and shared among experts in this field. The Italian Society of Colorectal Surgery and the Italian Association of Hospital Gastroenterologists selected a pool of experts to constitute a joint committee on the basis of their experience in treating pelvic floor disorders. The aim was to develop a position paper on the diagnostic and therapeutic aspects of faecal incontinence, to provide practical recommendations for a cost-effective diagnostic work-up and a tailored treatment strategy. The recommendations were defined and graded on the basis of levels of evidence in accordance with the criteria of the Oxford Centre for Evidence-Based Medicine, and were based on currently published scientific evidence. Each statement was drafted through constant communication and evaluation conducted both online and during face-to-face working meetings. A brief recommendation at the end of each paragraph allows clinicians to find concise responses to each diagnostic and therapeutic issue.

Severity of fecal urgency and incontinence in inflammatory bowel disease: clinical, manometric and sonographic predictors

BACKGROUND

Fecal incontinence (FI) and urgency are prevalent symptoms in patients with inflammatory bowel diseases (IBD). It is unclear which factors determine their severity. We evaluated associations of clinical activity, anorectal motility, and endoanal sonography with FI severity in IBD.

METHODS

Fifty-eight consecutive IBD patients and 14 healthy volunteers participated in a cross-sectional, tertiary-center study. Active disease was defined as Crohn's disease activity index ≥ 150 and as simple clinical colitis index > 2. We assessed anal pressures and fatigue rate index (FRI) of the external anal sphincter (EAS) by manometry, rectal compliance and sensitivity by balloon distension, and sphincter defects by endoanal ultrasound. Significant bivariate associations between these parameters and the fecal incontinence severity scale (FISS) were evaluated in multivariate analysis.

RESULTS

Twenty-seven patients (47%) reported urgency, 13 of which (22%) reported FI. Defects of the internal anal sphincter (IAS) and the EAS were diagnosed in 14 (24%) and 13 patients (22%), respectively. Patients had significantly lower rectal compliance and FRI compared with controls. FISS demonstrated significant bivariate associations with clinical disease activity (P = 0.0115), FRI (P = 0.0018), sonographic IAS and EAS defects (P < 0.0001 and 0.0059), rectal compliance (P = 0.0001), and volume at the threshold of a constant urge (Vurge, P = 0.0002). In multivariate analysis, FISS was associated with clinical disease activity (P = 0.0325), FRI (P = 0.0367), Vurge (P = 0.0091), and sonographic IAS defect(s) (P = 0.0008). The derived model explained 62% of the variance in FISS (P < 0.0001).

CONCLUSIONS

Clinical disease activity and manometric and sonographic anorectal parameters are associated with FI severity in IBD. Prospective studies are warranted to evaluate their predictive value in continence outcomes.

Obesity in Older Adults: Technical Review and Position Statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

Fatigue rate of the external anal sphincter

AIM

Studies of skeletal muscle show that fatigue rate corresponds to the proportion of fast-twitch and slow-twitch fibres that are present in the muscle. Limited work has been done on the fatigue rate of the external anal sphincter. We have prospectively studied fatigability of the external anal sphincter in women with faecal incontinence and women with normal bowel control.

METHOD

Anorectal manometry was measured by a station-pull technique using a water-filled microballoon. Fatigue rate was calculated from anal pressure measurements taken every 0.1 s over a 20-s squeeze.

RESULTS

Women with faecal incontinence (n=88, median -12 cmH(2) O/min) were less susceptible to fatigue than women with normal bowel control (n=36, median -43 cmH(2) O/min) (P<0.01). The external anal sphincter was less susceptible to fatigue with increasing age (P<0.01, r=0.499). In women with normal bowel control and in women with faecal incontinence fatigue rate was negatively correlated with maximum squeeze pressure (P<0.01, r=-0.287; P<0.01, r=-0.579).

CONCLUSION

The external anal sphincter was less susceptible to fatigue with increasing age. Women with faecal incontinence have a weaker but more fatigue-resistant external anal sphincter. This might correspond to a higher proportion of slow-twitch muscle fibres. Histological studies are needed to examine this hypothesis.

Consensus statement AIGO/SICCR: Diagnosis and treatment of chronic constipation and obstructed defecation (part I: Diagnosis)

Chronic constipation is a common and extremely trou-blesome disorder that significantly reduces the quality of life, and this fact is consistent with the high rate at which health care is sought for this condition. The aim of this project was to develop a consensus for the diagnosis and treatment of chronic constipation and obstructed defecation. The commission presents its results in a “Question-Answer” format, including a set of graded recommendations based on a systematic review of the literature and evidence-based medicine. This section represents the consensus for the diagnosis. The history includes information relating to the onset and duration of symptoms and may reveal secondary causes of constipation. The presence of alarm symptoms and risk factors requires investigation. The physical examination should assess the presence of lesions in the anal and perianal region. The evidence does not support the routine use of blood testing and colonoscopy or barium enema for constipation. Various scoring systems are available to quantify the severity of constipation; the Constipation Severity Instrument for constipation and the obstructed defecation syndrome score for obstructed defecation are the most reliable. The Constipation-Related Quality of Life is an excellent tool for evaluating the patient‘s quality of life. No single test provides a pathophysiological basis for constipation. Colonic transit and anorectal manometry define the pathophysiologic subtypes. Balloon expulsion is a simple screening test for defecatory disorders, but it does not define the mechanisms. Defecography detects structural abnormalities and assesses functional parameters. Magnetic resonance imaging and/or pelvic floor sonography can further complement defecography by providing information on the movement of the pelvic floor and the organs that it supports. All these investigations are indicated to differentiate between slow transit constipation and obstructed defecation because the treatments differ between these conditions.

Biofeedback for fecal incontinence: a randomized study comparing exercise regimens

BACKGROUND

Fecal incontinence affects up to 11% of Australian community-dwelling adults and 72% of nursing home residents. Biofeedback is a recommended conservative therapy when medication and pelvic floor exercises have failed to improve patient outcomes.

OBJECTIVE

This study aimed to investigate the impact of a new exercise regimen on the severity of fecal incontinence and the quality of life of participants.

DESIGN

This was a randomized clinical study.

SETTINGS

This study was conducted at the Anorectal Physiology Clinic, Townsville Hospital, Queensland, Australia.

PATIENTS

Seventy-two participants (19 male), with a mean age of 62.1 years, attended 5 clinic sessions: 4 weekly sessions followed by 4 weeks of home practice and a follow-up assessment session. A postal survey was conducted 2 years later.

INTERVENTION

Thirty-seven patients (12 male) were randomly assigned to the standard clinical protocol (sustained submaximal anal and pelvic floor exercises) and 35 patients (7 male) were randomly assigned to the alternative group (rapid squeeze plus sustained submaximal exercises).

MAIN OUTCOME MEASURES

The main outcomes were measured by use of the Cleveland Clinic Florida Fecal Incontinence score and the Fecal Incontinence Quality of Life Scale survey tool.

RESULTS

No significant differences were found between the 2 exercise groups at the beginning or at the end of the study or as a result of treatment in objective, quality-of-life, or fecal incontinence severity measures. Sixty-nine participants completed treatment. The severity of fecal incontinence decreased significantly (11.5/20 to 5.0/20, P < .001). Eighty-six percent (59/69) of participants reported improved continence. Quality of life significantly improved for all participants (P < .001). Results were sustained 2 years later. Patients who practiced at least the prescribed number of exercises had better outcomes than those who practiced fewer exercises.

LIMITATIONS

This study was limited because it involved a heterogeneous sample, it was based on subjective reporting of exercise performance, and loss to follow-up occurred because of the highly mobile population.

CONCLUSIONS

Patients attending this biofeedback program attained significant improvement in the severity of their fecal incontinence and in their quality of life. Although introduction of rapid muscle squeezes had little impact on fecal incontinence severity or patient quality of life, patient exercise compliance at prescribed or greater levels did.

Increased fatigability of external anal sphincter in inflammatory bowel disease: significance in fecal urgency and incontinence

BACKGROUND AND AIMS

Fatigability of external anal sphincter (EAS) has not been studied in inflammatory bowel disease (IBD) patients. We evaluated EAS fatigability in IBD patients with and without fecal incontinence (FI) and urgency, and correlated fatigability with demographic and clinical factors, and EAS endosonography.

METHODS

Fifty-eight consecutive IBD cases and 14 healthy volunteers completed Bristol stool form and a FI severity scale. Groups I, II and III included 27 patients with urgency including 13 with concomitant FI, 31 patients without FI or urgency, and 14 controls, respectively. We performed stationary pull-through manometry with an 8-channel water-perfused catheter. Fatigue rate (FR) was calculated by linear regression during a 20-s anal squeeze, and fatigue rate index (FRI) as the ratio of squeeze pressure increment to FR. EAS thickness and deficits were evaluated with an endoanal 10-MHz probe. Patients underwent sigmoidoscopy.

RESULTS

Group I demonstrated a higher Bristol score, more frequent defecations, and more EAS defects compared to group II. Resting, peak squeeze pressures and EAS thickness did not differ between groups. FR was increased in group I versus II, and in group II versus III; FRI was decreased in group I versus II and in group II versus III (p<0.001, adjusting for age and BMI). Gender, oral glucocorticoids, presence of proctitis, perianal disease and EAS defects did not interact with group membership on FR or FRI.

CONCLUSIONS

IBD is associated with increased fatigue rate and decreased fatigue rate index. These differences were even more striking in patients with incontinence or urgency.

Changes in fatigability of the striated anal canal after childbirth

AIM

Anal manometry is an established assessment tool for patients with faecal incontinence. Fatigue rate index (FRI) has been shown to discriminate between symptomatic patients and controls. The aim of this study was to compare manometry and fatigability of the anal canal in nulliparous women before and after childbirth.

METHOD

An air-filled manometry device was used to record maximum resting and squeeze pressures, fatigue rate (recorded over 20 s) and FRI. Recordings were made before and after vaginal delivery.

RESULTS

Nineteen women were studied. Resting anal canal pressure was not significantly different before and after delivery (57.1 +/- 13.6 vs 51.1 +/- 11.9 cmH(2)O, P = 0.1). Squeeze pressure was significantly lower postpartum (106.5 +/- 43.6 vs 75.5 +/- 45.6 cmH(2)O, P < 0.001). Fatigue rate was significantly reduced postpartum (-129.5 +/- 74.7 vs-76.1 +/- 54.8 cmH(2)O/min, P = 0.001), but FRI was not significantly altered (1.23 +/- 1.49 vs 1.41 +/- 1.27 min, P = 0.09).

CONCLUSION

Maximal squeeze pressure and fatigue rate of the anal canal are significantly reduced after childbirth. Resting anal canal pressure and FRI are not significantly different.

Function and dysfunction of the colon and anorectum in adults: working team report of the Swedish Motility Group (SMoG)

Symptoms of fecal incontinence and constipation are common in the general population. These can, however, be unreliably reported and are poorly discriminatory for underlying pathophysiology. Furthermore, both symptoms may coexist. In the elderly, fecal impaction always must be excluded. For patients with constipation, colon transit studies, anorectal manometry and defecography may help to identify patients with slow-transit constipation and/or pelvic floor dysfunction. The best documented medical treatments for constipation are the macrogols, lactulose and isphagula. Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. Surgery is restricted for a highly selected group of patients with severe slow-transit constipation and for those with large rectoceles that demonstrably cause rectal evacuatory impairment. For patients with fecal incontinence that does not resolve on antidiarrheal treatment, functional and structural evaluation with anorectal manometry and endoanal ultrasound or magnetic resonance (MR) of the anal canal may help to guide management. Sacral nerve stimulation is a rapidly evolving alternative when other treatments such as biofeedback and direct sphincter repair have failed. Advances in understanding the pathophysiology as a guide to treatment of patients with constipation and fecal incontinence is a continuing important goal for translational research. The content of this article is a summary of presentations given by the authors at the Fourth Meeting of the Swedish Motility Group, held in Gothenburg in April 2007.

The physiology of continence and evacuation

Continence is maintained by the coordinated function of the pelvic floor, rectum and anal sphincters. Evacuation occurs through a relaxed pelvic floor. The rectum acts to either store or expel stool both of which require cortical sensory awareness acting in conjunction with intramural and spinal reflexes that ensure timely defecation. The anal sphincters act individually and in unison in response to rectal distension and the sensation of rectal filling. Reflex relaxation of the internal anal sphincter has an additional sensory function in allowing sampling of rectal contents in the upper anal canal. Voluntary control of the external anal sphincter is key in the voluntary deferring of evacuation until a socially opportune moment. This review describes the physiological roles of each of these continence organs in order to understand the complex process of defecation.

External anal sphincter fatigue is not improved by N-acetylcysteine in an animal model

Oxidative stress is associated with skeletal muscle fatigue. This study tests the hypotheses that N-acetylcysteine (NAC) reduces fatigue and accelerates recovery of the rat external anal sphincter (EAS). Fifteen female Wistar rats were killed humanely. The EAS was mounted as a ring preparation and electrically stimulated with 50 Hz trains of 200 ms in duration every 4 s for three and a half minutes. Three groups were analysed: a control group (n = 5), a group pretreated with NAC (10(-4) mol L(-1); n = 5) and a group pretreated with NAC (10(-3) mol L(-1); n = 5). A novel fatigue index was formulated and was compared to a conventional method of expressing fatigue. There was no significant difference at concentrations of NAC (10(-4) mol L(-1); P > 0.05). At high concentrations of NAC (10(-3) mol L(-1)) there was a significant depression in peak twitch amplitude before fatigue (P = 0.04). N-acetylcysteine in both concentrations used, did not alter fatigue or recovery of the rat EAS. There was a significant positive correlation between the two methods of expressing fatigue but the conventional method produced a higher fatigue index (22.4% on average). N-acetylcysteine does not ameliorate fatigue or accelerate recovery of the EAS and may not be a useful medical therapy for faecal incontinence.

Investigation and treatment of faecal incontinence

Faecal incontinence is a debilitating condition affecting people of all ages, and significantly impairs quality of life. Proper clinical assessment followed by conservative medical therapy leads to improvement in more than 50% of cases, including patients with severe symptoms. Patients with advanced incontinence or those resistant to initial treatment should be evaluated by anorectal physiology testing to establish the severity and type of incontinence. Several treatment options with promising results exist. Patients with gross sphincter defects should undergo surgical repair. Those who fail to respond to sphincteroplasty and those with no anatomical defects have the option of either sacral nerve stimulation or other advanced procedures. Stoma formation should be reserved for patients who do not respond to any of the above procedures.

Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and the NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

Geriatric fecal incontinence

Fecal incontinence is a common problem in the elderly population,particularly in nursing homes, and is one of the common reasons for nursing home placement. In addition to the inconvenience of the incontinence for the patient and caregiver, it is associated with increased mortality. Identifiable physiologic changes in the anorectal region may contribute to the development of fecal incontinence.Fecal incontinence is a disorder of men and women, with an equal or greater prevalence in men in advancing years. All patients who have fecal incontinence warrant an initial medical evaluation,including the exclusion of fecal impaction. Cognitively impaired patients benefit most from habit training. Selected elderly patients who have fecal incontinence may benefit from biofeedback and surgical intervention.

Physiologic variables that predict the outcome of treatment for fecal incontinence

Identification of physiologic factors that predict response to fecal incontinence therapy would be helpful in choosing the optimal treatment and advising patients on the likelihood of a successful outcome. However, few physiologic parameters have been consistently identified as important in predicting response to either biofeedback or surgery. The process of isolating these factors has been hampered by heterogeneity in the definition of fecal incontinence, lack of consensus on what constitutes a successful outcome, lack of follow-up data, variations in the way "standard" treatments are implemented, and lack of properly powered randomized controlled trials. Among the physiologic variables that studies have generally found to be predictive of successful outcomes in biofeedback treatment are the threshold for external anal sphincter contraction after treatment, the inclusion of sensory training in treatment, and a reduction in volume for the first sensation after treatment. Factors that have not been found to be important in predicting outcome following biofeedback retraining include the duration of fecal incontinence, pudendal nerve damage, patient age, symptom severity, pretreatment anal canal pressures, and results of anal ultrasonography. The presence of some degree of anorectal sensation is the only preoperative assessment that has been found to be predictive of response to surgical therapy. It is recommended that outcome measures for fecal incontinence be more clearly defined, that future biofeedback studies elaborate the predictive value of pretreatment anorectal sensation and the response to sensory retraining, and that postsurgical measurements such as anal squeeze pressure and sphincter length be taken into account.

Randomized controlled trial of biofeedback for fecal incontinence

BACKGROUND & AIMS

Behavioral treatment (biofeedback) has been reported to improve fecal incontinence but has not been compared with standard care.

METHODS

A total of 171 patients with fecal incontinence were randomized to 1 of 4 groups: (1) standard care (advice); (2) advice plus instruction on sphincter exercises; (3) hospital-based computer-assisted sphincter pressure biofeedback; and (4) hospital biofeedback plus the use of a home electromyelogram biofeedback device. Outcome measures included diary, symptom questionnaire, continence score, patient's rating of change, quality of life (short-form 36 and disease specific), psychologic status (Hospital Anxiety and Depression scale), and anal manometry.

RESULTS

Biofeedback yielded no greater benefit than standard care with advice (53% improved in group 3 vs. 54% in group 1). There was no difference between the groups on any of the following measures: episodes of incontinence decreased from a median of 2 to 0 per week (P < 0.001). Continence score (worst = 20) decreased from a median of 11 to 8 (P < 0.001). Disease-specific quality of life, short-form 36 (vitality, social functioning, and mental health), and Hospital Anxiety and Depression scale all significantly improved. Patients improved resting, squeeze, and sustained squeeze pressures (all P < 0.002). These improvements were largely maintained 1 year after finishing treatment.

CONCLUSIONS

Conservative therapy for fecal incontinence improves continence, quality of life, psychologic well-being, and anal sphincter function. Benefit is maintained in the medium term. Neither pelvic floor exercises nor biofeedback was superior to standard care supplemented by advice and education.

[Sphincteric function quantification by measuring the capacity to sustain the squeeze pressure of the anal canal]

BACKGROUND

It has been demonstrated that the maximum squeeze pressure and the mean resting pressure do not reflect the true clinical situation of patients having fecal incontinence, as well as the functional status of the anal canal. Furthermore, a wrong diagnosis could be obtained and therefore misleading to a not effective treatment.

AIM

Under the hypothesis that squeezing and sustaining the anal canal contraction is more important than the maximum squeeze pressure, the capacity to sustain the squeeze pressure of the anal canal was analyzed aiming to quantify the sphincteric function.

METHODS

Seventy-two patients having fecal incontinence in different degrees (56 female) and 15 normal individuals (9 female) were submitted to anorectal manometry to measure the mean resting pressure, the maximum voluntary squeeze pressure and the capacity to sustain the squeeze pressure.

RESULTS

Normal individuals had normal values of mean resting pressure and maximum squeeze pressure, and adequate capacity to sustain the squeeze pressure of the canal anal. Incontinent patients had mean resting pressure and maximum squeeze pressure with normal or below normal pressoric values and similar profile of capacity to sustain which was moderate in the initial phase and worse in the intermediate and final phases, with decreasing of the capacity to sustain more than 35% in 78% of the patients. The maximum squeeze pressure presented excellent specificity (100%), but low sensitivity (46%) for fecal incontinence. Comparatively, the squeeze pressure presented high specificity (93%) and high sensitivity (78%) for fecal incontinence. Although the maximum squeeze pressure did not indicate false positive, it presented a 72% false negative. The probability of this event to happen with the capacity to sustain measure is 20% lower, and it was statistically significant.

CONCLUSION

Sphincteric function can be better analyzed by using the capacity to sustain the squeeze pressure. capacity to sustain indicates more precisely the functional capacity of the anal canal in relation to voluntary continence, and it is better than maximum squeeze pressure as an isolated index.

Functional results and visceral perception after ileo neo-rectal anastomosis in patients: a pilot study

INTRODUCTION

To reduce pouch related complications after restorative proctocolectomy, an alternative procedure was developed, the ileo neo-rectal anastomosis (INRA). This technique consists of rectal mucosa replacement by ileal mucosa and straight ileorectal anastomosis. Our study provides a detailed description of the functional results after INRA.

PATIENTS AND METHODS

Eleven patients underwent an INRA procedure with a temporary ileostomy. Anorectal function tests were performed two months prior to and six and 12 months after closure of the ileostomy and comprised: anal manometry, ultrasound examination, rectal balloon distension, and transmucosal electrical nerve stimulation (TENS). Function was subsequently related to the histopathology of rectal biopsy samples.

RESULTS

Median stool frequency decreased from 15/24 hours (10-25) to 6/24 hours (4-11) at one year. All patients reported full continence. Anal sensibility, and resting and squeeze pressures did not change after INRA. Rectal compliance decreased (2.1 (0.7-2.8) v 1.5 (0.4-2.2) and 1.4 (0.8-3.7) ml/mm Hg (p=0.03)) but the maximum tolerated volume increased (70 (50-118) v 96 (39-176) (NS) and 122 (56-185) ml (p=0.03)). Decreasing rectal sensitivity was found: the maximum tolerated pressure increased (14 (8-24) v 22 (8-34) (NS) and 26 (14-40) (p=0.02)) and the rectal threshold for TENS displayed a similar tendency. All patients displayed a low grade chronic inflammatory infiltrate in neorectal biopsy samples before closure of the ileostomy, with no change during follow up.

CONCLUSIONS

The technique of INRA provides a safe alternative for restorative surgery. Stool frequency after INRA improves with time and seems to be related to decreasing sensitivity and not to histopathological changes in the neorectum. Furthermore, after the INRA procedure, all patients reported full continence.

Manometric squeeze pressure difference parallels functional outcome after overlapping sphincter reconstruction

PURPOSE

This study was designed to evaluate the effectiveness of overlapping anal sphincter reconstruction and to determine the manometric parameters that correlate with a successful functional outcome.

METHODS

A retrospective review of patients who had undergone overlapping sphincter reconstruction for anal incontinence from 1988 to 1999 was undertaken. Only patients with preoperative and six-months-postoperative anal manometry were included in this study. Standard statistical tests were used to compare pre- and postoperative findings.

RESULTS

A total of 52 overlapping sphincter reconstructions were performed on 49 patients (46 females). The mean age was 44 (+/- standard error, 15.8; range, 20-81) years, with follow-up at six months. Forty-two patients had a history of complicated vaginal delivery (episiotomies, tears, forceps delivery); 36 patients had a history of anal or perineal surgery; and two patients had perianal Crohn's disease. Nine patients (17 percent) had undergone prior sphincter repair. Incontinence grade improved in 37 patients (71 percent), and complete continence returned in 21 patients (40 percent). The presence of a rectovaginal fistula, postoperative complications, previous sphincter repair, and increase in pudendal nerve terminal motor latency did not affect functional outcome (P = not significant). Patients older than 50 years had a better functional outcome than their younger counterparts after sphincter repair (P = 0.02). Although mean maximal squeeze pressure and mean anal sphincter length increased significantly after sphincter reconstruction (P = 0.0006 and 0.004, respectively), only squeeze pressure difference correlated with functional outcome (r = 0.37; P = 0.007).

CONCLUSIONS

Overlapping sphincter reconstruction improved anal function in the majority of patients. The most important factor in the return to normal sphincter function is an increase in squeeze pressure.

Biofeedback for fecal incontinence using transanal ultrasonography: novel approach

PURPOSE

Neosphincter procedures may prove to be the treatment of choice for patients with neuropathic fecal incontinence but are rarely proposed for milder forms of the disease. Biofeedback may prove beneficial to these patients but is yet unproven. The objectives of this study were to develop a method of performing biofeedback using transanal ultrasound to teach the patient to contract repetitively and to determine biologic measures of sphincter function using transanal ultrasound in healthy and incontinent patients.

METHODS

Initial uncontrolled studies were performed to determine the compliance, normal values, biologic measures of external sphincter strength (isotonic and isometric fatigue times), and early efficacy data using continence scores and visual analog scale scores.

RESULTS

Forty-four patients were assessed during three months, with relative improvements in continence scores (St. Mark's Hospital, 40 percent; Pescatori, 20 percent) and patient and investigator visual analog scale scores (38 percent for both) and measurable increase in biologic fatigue times measured by transanal ultrasound.

CONCLUSIONS

Transanal ultrasound seems to be a method of teaching external sphincter contraction and measuring sphincter strength with good initial compliance. Clinically and statistically significant improvements in incontinence scores, visual analog scale scores, and biologic strength of the external sphincter were detected in the short-term follow-up with uncontrolled data. The randomized, controlled trial that we have begun will either confirm or refute these results.