New method for the dynamic assessment of anorectal function in constipation

Non-drug therapies for the management of chronic constipation in adults: the CapaCiTY research programme including three RCTs

Background

Chronic constipation affects 1–2% of adults and significantly affects quality of life. Beyond the use of laxatives and other basic measures, there is uncertainty about management, including the value of specialist investigations, equipment-intensive therapies using biofeedback, transanal irrigation and surgery.

Objectives

(1) To determine whether or not standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback is more clinically effective than standardised specialist-led habit training alone, and whether or not outcomes of such specialist-led interventions are improved by stratification to habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or habit training alone based on prior knowledge of anorectal and colonic pathophysiology using standardised radiophysiological investigations; (2) to compare the impact of transanal irrigation initiated with low-volume and high-volume systems on patient disease-specific quality of life; and (3) to determine the clinical efficacy of laparoscopic ventral mesh rectopexy compared with controls at short-term follow-up.

Design

The Chronic Constipation Treatment Pathway (CapaCiTY) research programme was a programme of national recruitment with a standardised methodological framework (i.e. eligibility, baseline phenotyping and standardised outcomes) for three randomised trials: a parallel three-group trial, permitting two randomised comparisons (CapaCiTY trial 1), a parallel two-group trial (CapaCiTY trial 2) and a stepped-wedge (individual-level) three-group trial (CapaCiTY trial 3).

Setting

Specialist hospital centres across England, with a mix of urban and rural referral bases.

Participants

The main inclusion criteria were as follows: age 18–70 years, participant self-reported problematic constipation, symptom onset > 6 months before recruitment, symptoms meeting the American College of Gastroenterology’s constipation definition and constipation that failed treatment to a minimum basic standard. The main exclusion criteria were secondary constipation and previous experience of study interventions.

Interventions

CapaCiTY trial 1: group 1 – standardised specialist-led habit training alone (n = 68); group 2 – standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (n = 68); and group 3 – standardised radiophysiological investigations-guided treatment (n = 46) (allocation ratio 3 : 3 : 2, respectively). CapaCiTY trial 2: transanal irrigation initiated with low-volume (group 1, n = 30) or high-volume (group 2, n = 35) systems (allocation ratio 1 : 1). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy performed immediately (n = 9) and after 12 weeks’ (n = 10) and after 24 weeks’ (n = 9) waiting time (allocation ratio 1 : 1 : 1, respectively).

Main outcome measures

The main outcome measures were standardised outcomes for all three trials. The primary clinical outcome was mean change in Patient Assessment of Constipation Quality of Life score at the 6-month, 3-month or 24-week follow-up. The secondary clinical outcomes were a range of validated disease-specific and psychological scoring instrument scores. For cost-effectiveness, quality-adjusted life-year estimates were determined from individual participant-level cost data and EuroQol-5 Dimensions, five-level version, data. Participant experience was investigated through interviews and qualitative analysis.

Results

A total of 275 participants were recruited. Baseline phenotyping demonstrated high levels of symptom burden and psychological morbidity. CapaCiTY trial 1: all interventions (standardised specialist-led habit training alone, standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback and standardised radiophysiological investigations-guided habit training alone or habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback) led to similar reductions in the Patient Assessment of Constipation Quality of Life score (approximately –0.8 points), with no statistically significant difference between habit training alone and habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (–0.03 points, 95% confidence interval –0.33 to 0.27 points; p = 0.8445) or between standardised radiophysiological investigations and no standardised radiophysiological investigations (0.22 points, 95% confidence interval –0.11 to 0.55 points; p = 0.1871). Secondary outcomes reflected similar levels of benefit for all interventions. There was no evidence of greater cost-effectiveness of habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or stratification by standardised radiophysiological investigations compared with habit training alone (with the probability that habit training alone is cost-effective at a willingness-to-pay threshold of £30,000 per quality-adjusted life-year gain; p = 0.83). Participants reported mixed experiences and similar satisfaction in all groups in the qualitative interviews. CapaCiTY trial 2: at 3 months, there was a modest reduction in the Patient Assessment of Constipation Quality of Life score, from a mean of 2.4 to 2.2 points (i.e. a reduction of 0.2 points), in the low-volume transanal irrigation group compared with a larger mean reduction of 0.6 points in the high-volume transanal irrigation group (difference –0.37 points, 95% confidence interval –0.89 to 0.15 points). The majority of participants preferred high-volume transanal irrigation, with substantial crossover to high-volume transanal irrigation during follow-up. Compared with low-volume transanal irrigation, high-volume transanal irrigation had similar costs (median difference –£8, 95% confidence interval –£240 to £221) and resulted in significantly higher quality of life (0.093 quality-adjusted life-years, 95% confidence interval 0.016 to 0.175 quality-adjusted life-years). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy resulted in a substantial short-term mean reduction in the Patient Assessment of Constipation Quality of Life score (–1.09 points, 95% confidence interval –1.76 to –0.41 points) and beneficial changes in all other outcomes; however, significant increases in cost (£5012, 95% confidence interval £4446 to £5322) resulted in only modest increases in quality of life (0.043 quality-adjusted life-years, 95% confidence interval –0.005 to 0.093 quality-adjusted life-years), with an incremental cost-effectiveness ratio of £115,512 per quality-adjusted life-year.

Conclusions

Excluding poor recruitment and underpowering of clinical effectiveness analyses, several themes emerge: (1) all interventions studied have beneficial effects on symptoms and disease-specific quality of life in the short term; (2) a simpler, cheaper approach to nurse-led behavioural interventions appears to be at least as clinically effective as and more cost-effective than more complex and invasive approaches (including prior investigation); (3) high-volume transanal irrigation is preferred by participants and has better clinical effectiveness than low-volume transanal irrigation systems; and (4) laparoscopic ventral mesh rectopexy in highly selected participants confers a very significant short-term reduction in symptoms, with low levels of harm but little effect on general quality of life.

Limitations

All three trials significantly under-recruited [CapaCiTY trial 1, n = 182 (target 394); CapaCiTY trial 2, n = 65 (target 300); and CapaCiTY trial 3, n = 28 (target 114)]. The numbers analysed were further limited by loss before primary outcome.

Trial registration

Current Controlled Trials ISRCTN11791740, ISRCTN11093872 and ISRCTN11747152.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 14. See the NIHR Journals Library website for further project information.

Stepped-wedge randomised trial of laparoscopic ventral mesh rectopexy in adults with chronic constipation: study protocol for a randomized controlled trial

Background

Laparoscopic ventral mesh rectopexy (LVMR) is an established treatment for external full-thickness rectal prolapse. However, its clinical efficacy in patients with internal prolapse is uncertain due to the lack of high-quality evidence.

Methods

An individual level, stepped-wedge randomised trial has been designed to allow observer-blinded data comparisons between patients awaiting LVMR with those who have undergone surgery. Adults with symptomatic internal rectal prolapse, unresponsive to prior conservative management, will be eligible to participate. They will be randomised to three arms with different delays before surgery (0, 12 and 24 weeks). Efficacy outcome data will be collected at equally stepped time points (12, 24, 36 and 48 weeks). The primary objective is to determine clinical efficacy of LVMR compared to controls with reduction in the Patient Assessment of Constipation Quality of Life (PAC-QOL) at 24 weeks serving as the primary outcome. Secondary objectives are to determine: (1) the clinical effectiveness of LVMR to 48 weeks to a maximum of 72 weeks; (2) pre-operative determinants of outcome; (3) relevant health economics for LVMR; (4) qualitative evaluation of patient and health professional experience of LVMR and (5) 30-day morbidity and mortality rates.

Discussion

An individual-level, stepped-wedge, randomised trial serves the purpose of providing an untreated comparison for the active treatment group, while at the same time allowing the waiting-listed participants an opportunity to obtain the intervention at a later date. In keeping with the basic ethical tenets of this design, the average waiting time for LVMR (12 weeks) will be shorter than that for routine services (24 weeks).

Trial registration

ISRCTN registry, ISRCTN11747152. Registered on 30 September 2015. The trial was prospectively registered (first patient enrolled on 21 March 2016).

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2456-3) contains supplementary material, which is available to authorized users.

Habit training versus habit training with direct visual biofeedback in adults with chronic constipation: study protocol for a randomised controlled trial

Background

Constipation affects up to 20% of adults. Chronic constipation (CC) affects 1–2% of adults. Patient dissatisfaction is high; nearly 80% feel that laxative therapy is unsatisfactory and symptoms have significant impact on quality of life. There is uncertainty about the value of specialist investigations and whether equipment-intensive therapies using biofeedback confer additional benefit when compared with specialist conservative advice.

Methods/design

A three-arm, parallel-group, multicentre randomised controlled trial.

Objectives: to determine whether standardised specialist-led habit training plus pelvic floor retraining using computerised biofeedback is more clinically effective than standardised specialist-led habit training alone; to determine whether outcomes are improved by stratification based on prior investigation of anorectal and colonic pathophysiology. Primary outcome measure is response to treatment, defined as a 0.4-point (10% of scale) or greater reduction in Patient Assessment of Constipation–Quality of Life (PAC-QOL) score 6 months after the end of treatment. Other outcomes up to 12 months include symptoms, quality of life, health economics, psychological health and qualitative experience.

Hypotheses: (1) habit training (HT) with computer-assisted direct visual biofeedback (HTBF) results in an average reduction in PAC-QOL score of 0.4 points at 6 months compared to HT alone in unselected adults with CC, (2) stratification to either HT or HTBF informed by pathophysiological investigation (INVEST) results in an average 0.4-point reduction in PAC-QOL score at 6 months compared with treatment not directed by investigations (No-INVEST).

Inclusion: chronic constipation in adults (aged 18–70 years) defined by self-reported symptom duration of more than 6 months; failure of previous laxatives or prokinetics and diet and lifestyle modifications. Consenting participants (n = 394) will be randomised to one of three arms in an allocation ratio of 3:3:2: [1] habit training, [2] habit training and biofeedback or [3] investigation-led allocation to one of these arms. Analysis will be on an intention-to-treat basis.

Discussion

This trial has the potential to answer some of the major outstanding questions in the management of chronic constipation, including whether costly invasive tests are warranted and whether computer-assisted direct visual biofeedback confers additional benefit to well-managed specialist advice alone.

Trial registration

International Standard Randomised Controlled Trial Number: ISRCTN11791740. Registered on 16 July 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1880-0) contains supplementary material, which is available to authorized users.

Chronic severe constipation: current pathophysiological aspects, new diagnostic approaches, and therapeutic options

Chronic constipation is a considerable problem because it significantly affects the quality of a patient's life. Constipation can be diagnosed at every age and is more frequent in women and among the elderly. In epidemiological studies, its incidence is estimated at 2-27% in the general population. Chronic constipation may be primary or secondary. However, primary constipation (functional or idiopathic) can be classified into normal transit constipation, slow transit constipation, and pelvic outlet obstruction. In this review we make an attempt to present the current pathophysiological aspects and new therapeutic options for chronic idiopathic constipation, particularly highlighting the value of patient assessment for accurate diagnosis of the cause of the problem, thus helping in the choice of appropriate treatment.

Joint hypermobility and rectal evacuatory dysfunction: an etiological link in abnormal connective tissue?

BACKGROUND

  Previous studies report an association between joint hypermobility (JHM), as a clinical feature of underlying connective tissue (CT) disorder, and pelvic organ prolapse. However, its association with rectal evacuatory dysfunction (RED) has not been evaluated. To investigate the prevalence of JHM in the general population and in patients with symptoms of RED referred for anorectal physiological investigation.

METHODS

Bowel symptom and Rome III questionnaires to detect irritable bowel syndrome were sent to 273 patients with RED. Patients then underwent full investigation, including evacuation proctography. A validated 5-point self-reported questionnaire was used to assess JHM in both the patient group and 100 age- and sex-matched controls [87 female, median age 55 (range 28-87)].

KEY RESULTS

Seventy-three patients were excluded from analysis (incomplete questionnaire or investigation). Of 200, 65 patients [32%: 63 female, median age 52 (range 15-80)] and 14% of controls (P = 0.0005 vs patients) had features satisfying criteria for JHM. Overall constipation score (P < 0.0001), abdominal pain (P = 0.003), need for manual assistance (P = 0.009), and use of laxatives (P = 0.03) were greater in the JHM group than the non-JHM group. On proctography, 56 of JHM patients (86%) were found to have significant morphological abnormalities (e.g. functional rectocoele), compared with 64% of the non-JHM group (P = 0.001).

CONCLUSIONS & INFERENCES

The greater prevalence of JHM in patients with symptoms of RED, and the demonstration of significantly higher frequencies of morphological abnormalities than those without JHM, raises the possibility of an important pathoaetiology residing in either an enteric or supporting pelvic floor abnormality of CT.

Neuroanatomy and physiology of colorectal function and defaecation: from basic science to human clinical studies

Colorectal physiology is complex and involves programmed, coordinated interaction between muscular and neuronal elements. Whilst a detailed understanding remains elusive, novel information has emerged from recent basic science and human clinical studies concerning normal sensorimotor mechanisms and the organization and function of the key elements involved in the control of motility. This chapter summarizes these observations to provide a contemporary review of the neuroanatomy and physiology of colorectal function and defaecation.

Correlations of anatomical parameters in dynamic pelvic CT and conventional defecography for patients with rectal prolapse

PURPOSE

To evaluate the correlations of anatomical parameters between dynamic pelvic CT (D-PCT) and conventional defecography (CD) for patients with rectal prolapse.

MATERIAL AND METHODS

Anatomical parameters in multislice CT scanning of the pelvis performed at rest and during simulated defecation (D-PCT) were studied with those of CD to evaluate the correlations in both methods for 10 patients with rectal prolapse.

RESULT

The correlation coefficients of the pubococcygeal line and the pubosacral line were r=0.6 and r=0.8 respectively. The length from anal verge to pubococcygeal line and to the pubosacral line showed a good correlation of r=0.7. The length of puborectal muscle showed a good correlation of r=0.8. Anorectal angle was significantly well correlated between two methods (r=0.9, p<0.05). The lengths of anococcygeal length and anosacral length showed a good correlation.

CONCLUSION

The anatomical parameters measured by D-PCT were well correlated with those by CD. D-PCT might be an alternative tool for anatomical evaluation of the anorectal region in patients with rectal prolapse.

Novel concepts in the diagnosis, pathophysiology and management of idiopathic megabowel

A proportion of patients with intractable constipation have persistent dilatation of the bowel, which in the absence of an organic cause is termed idiopathic megabowel (IMB). Whilst uncommon, this condition results in considerable morbidity. Traditional methods of identifying such patients are associated with inherent methodological limitations with anorectal manometry and contrast studies overestimating and underestimating the prevalence of the condition, respectively. Recently, controlled, pressure-based distension during fluoroscopic imaging has allowed more accurate identification of patients on the basis of a rectal diameter > 6.3 cm at the minimum distension pressure. Histopathological abnormalities of all three final effectors of sensorimotor function have been reported, although it remains unclear whether these changes are primary, secondary or epiphenomic. Physiological abnormalities of sensorimotor function, namely impaired perception of rectal distension and delayed colonic transit are well documented in patients with IMB. Further, the recent demonstration of two subgroups of patients, defined on the basis of rectal compliance, suggests the possibility that they differ pathophysiologically, although the clinical relevance of this distinction is uncertain. Surgery is performed when conservative therapy is ineffective or poorly tolerated. Numerous procedures have been attempted with variable success rates and significant mortality and morbidity. Surgery should preferably be performed in specialist centres given the relative infrequency with which such patients are encountered, and that they require comprehensive clinical, psychological and physiological evaluation preoperatively.

A novel technique to identify patients with megarectum

PURPOSE

Traditional methods of identifying patients with persistent dilation of the rectum, or megarectum, are associated with inherent methodologic limitations. The purpose of this study was to use a barostat to establish criteria for the diagnosis of megarectum and to assess rectal diameter during isobaric (barostat) and volumetric (barium contrast) distention protocols in constipated patients with megarectum on anorectal manometry.

METHODS

During fluoroscopic screening, rectal diameter was measured at minimum distending pressure of the rectum, achieved using a barostat. It was also measured during evacuation proctography (volumetric distention). Having established a normal range in 25 healthy volunteers, 30 constipated patients with evidence of megarectum on anorectal manometry (elevated maximum tolerable volume on latex balloon distention) were studied. A further 10 constipated patients without evidence of megarectum were studied (normal rectum).

RESULTS

Megarectum was diagnosed when the rectal diameter was greater than 6.3 cm at minimum distending pressure. Rectal diameter at minimum distending pressure was increased in 20 patients (67 percent) with megarectum on anorectal manometry, but was normal in the remaining 10 patients (33 percent) and all patients with a normal rectum on anorectal manometry. Rectal diameter was increased at evacuation proctography in only 15 patients (50 percent) with evidence of megarectum on anorectal manometry.

CONCLUSIONS

The prevalence of megarectum is overestimated and underestimated when rectal diameter is assessed using anorectal manometry and contrast studies, respectively. Controlled (pressure-based) distention combined with fluoroscopic imaging allowed accurate identification of patients with megarectum on the basis of a rectal diameter greater than 6.3 cm at the minimum distention pressure. Measurement of rectal diameter at minimum distention pressure may be useful in those patients with an elevated maximum tolerable volume on anorectal manometry when surgery is being contemplated.

Videomanometry of the pelvic organs: a comparison of the normal lower urinary and gastrointestinal tracts

BACKGROUND

Both the lower urinary tract (LUT) and the caudal part of the lower gastrointestinal tract (LGIT) are innervated by the sacral spinal cord. We aimed to compare the normal physiology of the LUT and LGIT using the same videomanometry method.

METHODS

We recruited fifteen healthy volunteers (eight men and seven women; mean age, 60 years). The videomanometric measures included fluoroscopic images, subtracted bladder/rectal pressures, urethral/anal sphincter pressures, sphincter electromyography, and urinary/fecal flow.

RESULTS

During the resting phase, the urethral/anal sphincter pressures showed almost the same values (mean, 70 cmH2O and 68 cmH2O, respectively). During the storage phase, the volumes at first sensation and maximum capacity for the LGIT (129 mL and 320 mL) were slightly smaller than those for the LUT (170 mL and 405 mL). Compliance of the LGIT (65 mL/cmH2O) was almost as high as that of the LUT (99 mL/cmH2O). However, the LGIT showed spontaneous phasic rectal contractions (SPRC) that were never seen in the bladder. None of the subjects experienced leakage during bladder/rectal filling. During the evacuation phase, rectal contraction on defecation (14 cmH2O) was present, but was weaker than bladder contraction on micturition (42 cmH2O; P < 0.01). Abdominal strain on defecation (70 cmH2O) was greater than that on micturition (25 cmH2O; P < 0.01). Sphincter pressure increase on defecation (13 cmH2O) was greater than that on micturition (-52 cmH2O). An illustrative case of SPRC that were seen during urodynamic recording was shown.

CONCLUSION

SPRC and abdominal strain are features of the LGIT, whereas micturition bladder contraction is a feature of the LUT. These features can aid in understanding the possible rectal 'artifacts' of videourodynamics and neurogenic pelvic organ dysfunction.

Constipation of anorectal outlet obstruction: pathophysiology, evaluation and management

Constipation is a subjective symptom of various pathological conditions. Incidence of constipation fluctuates from 2 to 30% in the general population. Approximately 50% of constipated patients referred to tertiary care centers have obstructed defecation constipation. Constipation of obstructed defecation may be due to mechanical causes or functional disorders of the anorectal region. Mechanical causes are related to morphological abnormalities of the anorectum (megarectum, rectal prolapse, rectocele, enterocele, neoplasms, stenosis). Functional disorders are associated with neurological disorders and dysfunction of the pelvic floor muscles or anorectal muscles (anismus, descending perineum syndrome, Hirschsprung's disease). However, this type of constipation should be differentiated by colonic slow transit constipation which, if coexists, should be managed to a second time. Assessment of patients with severe constipation includes a good history, physical examination and specialized investigations (colonic transit time, anorectal manometry, rectal balloon expulsion test, defecography, electromyography), which contribute to the diagnosis and the differential diagnosis of the cause of the obstructed defecation. Thereby, constipated patients can be given appropriate treatment for their problem, which may be conservative (bulk agents, high-fiber diet or laxatives), biofeedback training or surgery.

The Colorectal Development Unit: impact on functional outcome for the electrically stimulated gracilis neoanal sphincter

OBJECTIVE

A Colorectal Development Unit (CDU) was established to treat patients with end stage faecal incontinence with the electrically stimulated gracilis neoanal sphincter (ESGN). The aim of this study was to investigate the impact of the CDU on functional outcome and complications.

METHODS

From March 1997 to March 2003, 53 patients underwent ESGN formation. Results were compared with 65 patients undergoing ESGN surgery prior to the establishment of the unit (pre-CDU) between 1988 and 1997, which were similar with regard to age, sex, aetiology and follow-up.

RESULTS

Thirty-three (70%) CDU patients had a good functional outcome defined as continence to solid and liquid stool, a significant improvement when compared to the pre-CDU group, successful in 29 (45%) (P = 0.01). Episodes of technical complications leading to stimulator replacement were significantly reduced, from 25 to 3 over time (P < 0.001). Severe septic episodes were significantly reduced from 21 to four (P = 0.003) but there was no significant change in the incidence of postoperative evacuatory dysfunction.

CONCLUSION

Since setting up a CDU, a successful outcome has been achieved in 33 (70%) of 47 patients undergoing ESGN surgery, which represents a significant improvement over time. This is probably related to improved patient assessment and selection, more reliable equipment and increased operative and peri-operative experience that come with a multidisciplinary team approach.

Rectal intussusception in symptomatic patients is different from that in asymptomatic volunteers

Background

Rectal intussusception is a common finding at evacuation proctography in both symptomatic and asymptomatic individuals. Little information exists, however, as to whether intussusception morphology differs between patients with evacuatory dysfunction and healthy volunteers.

Methods

Thirty patients (19 women; median age 44 (range 21–76) years) with disordered rectal evacuation, in whom an isolated intussusception was seen on proctography, were studied. Various morphological parameters were measured, and compared with those from 11 asymptomatic controls (six women; median age 30 (range 24–38) years) found, from 31 volunteers, to have rectal intussusception. Intussusceptum thickness greater than 3 mm was designated as full thickness. Intussuscepta impeding evacuation were deemed to be occluding.

Results

Twenty-two patients had full-thickness intussusception, compared with two controls (P = 0·003). Intussusceptum thickness was significantly greater in the symptomatic group (anterior component: P = 0·004; posterior: P = 0·011). Twenty patients in the symptomatic group, but only three subjects in the control group, had a mechanically occluding intussusception (P = 0·043), although only three patients demonstrated evacuatory dynamics outside the normal range.

Conclusion

Rectal intussusception in patients with evacuatory dysfunction is more advanced morphologically than that seen in asymptomatic controls; it is predominantly full thickness in patients and mucosal in controls. However, caution is required when selecting patients for intervention based solely on radiological findings.

Pelvic organ prolapse, constipation, and dietary fiber intake in women: a case-control study

OBJECTIVE

This study was undertaken to determine whether there is an association among pelvic organ prolapse, constipation, and dietary fiber intake.

STUDY DESIGN

Sixty consecutive women with prolapse were compared with 30 control women without prolapse. All women completed 2 validated questionnaires to assess constipation and dietary fiber intake. Multivariate analysis was performed.

RESULTS

The risk for constipation was greater in women with prolapse than controls (odds ratio 4.03, 95% CI 1.5-11.4). Median insoluble fiber intake was significantly lower in women with prolapse (2.4 g) than controls (5.8 g, P < .01). The increased risk for constipation was reduced but remained significant after controlling for age and insoluble dietary fiber intake (odds ratio 2.9, 95% CI 1.1-13.5).

CONCLUSION

Women with pelvic organ prolapse are at a higher risk for constipation than controls. This increased risk for constipation is partially explained by lower intake of dietary insoluble fiber by women with prolapse than controls.

Medium-term results of vertical reduction rectoplasty and sigmoid colectomy for idiopathic megarectum

Background

Vertical reduction rectoplasty (VRR) was devised specifically to address the physiological abnormalities present in the rectum of patients with idiopathic megarectum (IMR). This study evaluated the medium-term clinical and physiological results of VRR.

Methods

VRR and sigmoid colectomy was performed in ten patients with IMR and constipation (six women). Patients were evaluated before and a median of 60 (range 28–74) months after surgery by assessment of symptoms using scoring systems and anorectal physiological measurements. Independent, detailed postoperative evaluation of rectal diameter, compliance, and sensory and evacuatory function was performed.

Results

There were no deaths or late complications. Symptoms recurred necessitating permanent ileostomy formation in two patients. Median (range) constipation scores improved from 22 (18–27) before to 10 (0–24) after surgery (P = 0·016). Median (range) bowel frequency increased from 1·5 (0·2–7) to 7 (0·5–21) per week (P = 0·016). Rectal diameter, compliance and sensory function were normal in seven of eight patients after surgery. Evacuatory function and colonic transit were each normalized in two of eight patients after VRR.

Conclusion

VRR corrected rectal diameter, compliance and sensory function in most patients, and clinical benefit was sustained in the medium term. The procedure was associated with a low morbidity, and no mortality and should be considered in the surgical management of IMR.

Rectal intussusception: characterization of symptomatology

PURPOSE

Rectal intussusception is a common finding at evacuation proctography; however, its significance has been debated. This study was designed to characterize clinically and physiologically a large group of patients with rectal intussusception and test the hypothesis that certain symptoms are predictive of this finding on evacuation proctography.

METHODS

A total of 896 patients underwent evacuation proctography from which three groups were identified: those with isolated rectal intussusception (n = 125), those with isolated rectocele (n = 100), and those with both abnormalities (n = 152). Multivariate analyses were used to identify symptoms predictive of findings by evacuation proctography.

RESULTS

The symptoms of anorectal pain and prolapse were highly predictive of the finding of isolated intussusception over rectocele (odds ratio, 3.6, P = 0.006; odds ratio, 4.9, P < 0.001) or combined intussusception and rectocele (odds ratio, 2.9, P = 0.02; odds ratio, 2.4, P = 0.03). The symptom of "toilet revisiting" was associated with the finding of rectoanal intussusception (odds ratio, 3.55, P = 0.04). Although patients with mechanically obstructing intussuscepta evacuated slower and less completely (P < 0.001) than those with nonobstructing intussuscepta, no symptom was predictive of this finding on evacuation proctography.

CONCLUSIONS

Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.

External pelvic rectal suspension (the Express procedure) for full-thickness rectal prolapse: evolution of a new technique

OBJECTIVE

The Délorme's operation for rectal prolapse is a safe procedure but has a high recurrence rate. We aimed to develop an operation akin to it, but designed to reduce this deficit.

PATIENTS AND METHODS

Thirty-one consecutive patients with rectal prolapse were included in the study. Initially, a conventional Délorme's procedure was performed and sutures or strips of Gore-Tex were attached circumferentially to the apex of the prolapse, tunneled subcutaneously, and anchored to the external surface of the pelvis. Subsequently, the procedure was modified. Acellular porcine collagen strips were used and buried within the apex without plication of the denuded rectal musculature. Patients were formally assessed preoperatively and four months postoperatively by symptom and quality of life questionnaires and subsequently by regular clinical review.

RESULTS

In the Gore-Tex group (N = 11; males:females = 10:1; mean age, 61 years) three patients underwent suture repair and eight had strip fixation. All suture repairs developed sepsis and one patient had a recurrence. Seven of the strip fixations (88 percent) developed sepsis that resulted in implant extrusion. There was one full-thickness and one mucosal recurrence after a median follow-up of 25 months. In the collagen group (N = 20; males:females = 2:18; mean age, 63 years), sepsis occurred in four patients, requiring surgical intervention in one patient (5 percent) (cf Gore-Tex group, P = 0.002). There was one mucosal and three full-thickness (15 percent) recurrences after a median follow-up of 14 months (cf Gore-Tex group, P = not significant). Significant improvements in symptom and quality of life scores were recorded in both groups at four months.

CONCLUSION

A new, minimally invasive perineal procedure for rectal prolapse has been developed and initial data testify to its relative safety provided collagen is used. It remains to be seen whether long-term recurrence rates will be lower than those of conventional perineal procedures.

Rectal hyposensitivity: a disorder of the rectal wall or the afferent pathway? An assessment using the barostat

OBJECTIVES

Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension. Diagnosis on the basis of abnormal threshold volumes on balloon distension alone may be inaccurate due to the influence of differing rectal wall properties. The aim of this study was to investigate whether RH was actually due to impaired afferent nerve function or whether it could be secondary to abnormalities of the rectal wall.

METHODS

A total of 50 patients were referred consecutively to a tertiary referral unit for physiologic assessment of constipation (Rome II criteria), 25 of whom had associated fecal incontinence. Thirty patients had RH (elevated threshold volumes on latex balloon distension), and 20 patients had normal rectal sensation (NS). Results were compared with those obtained in 20 healthy volunteers (HV). All subjects underwent standard anorectal physiologic investigation, and assessment of rectal compliance, adaptive response to isobaric distension at urge threshold, and postprandial rectal response, using an electromechanical barostat.

RESULTS

Mean rectal compliance was significantly elevated in patients with RH compared to NS and HV (p < 0.001). However, 16 patients with RH (53%) had normal compliance. Intensity of the urge to defecate during random phasic isobaric distensions was significantly reduced in patients with RH compared to NS and HV (p < 0.001). The adaptive response at urge threshold was reduced in patients with RH compared to NS and HV (p < 0.001), although spontaneous adaptation at operating pressure was similar in all three groups studied (p= 0.3). Postprandially, responses were similar between groups.

CONCLUSIONS

In patients found to have RH on simple balloon distension, impaired perception of rectal distension may be partly explained in one subgroup by abnormal rectal compliance. However, a second subgroup exists with normal rectal wall properties, suggestive of a true impairment of the afferent pathway. The barostat has an important role in the identification of these subgroups of patients.

Open-magnet MR defaecography compared with evacuation proctography in the diagnosis and management of patients with rectal intussusception

OBJECTIVE

The aim of this study was to determine whether open-magnet magnetic resonance (MR) defaecography could provide more useful clinical information than evacuation proctography (EP) alone in the evaluation of a cohort of patients with full-thickness rectal intussusception and could assist in decisions concerning management.

METHODS

Ten patients (4 male; median age 43, range 30-65) with symptomatic circumferential rectal intussusception diagnosed on EP, underwent open-magnet MR defaecography. Pathologies visible with each technique were recorded and 12 parameters of anorectal configuration and morphology measured and compared.

RESULTS

There was discordance in the diagnosis of rectal intussusception in three cases. In another two patients, MR defaecography demonstrated mucosal descent only. Measurements of anorectal configuration and morphology were similar between techniques; only rectal size and lateral dimensions of the rectocoele were significantly different, being smaller on MR defaecography than EP. Two patients were shown on MR defaecography to have significant bladder descent and two female patients had significant vaginal descent.

CONCLUSION

EP remains the first line investigation for the diagnosis of rectal intussusception, but may not distinguish mucosal from full-thickness descent. MR defaecography further complements EP by giving information on movements of the whole pelvic floor, 30% of the patients studied having associated abnormal anterior and/or middle pelvic organ descent. If surgery is planned for patients with rectal intussusception, MR defaecography provides useful information regarding the presence and degree of anterior pelvic compartment descent that may need to be addressed if a good functional outcome is to be achieved.

Rectocele: pathogenesis and surgical management

BACKGROUND

Rectocele is a common finding in patients with intractable evacuatory disorders. Although much rectocele surgery is conducted by gynecologists en passant with other forms of vaginal surgery, many reports lack appreciation of the importance of coincident anorectal symptoms, and do not report functional and clinical outcome data. The pathogenesis of rectocele is still controversial, as is the embryological and anatomical importance of the rectovaginal septum as well as recognizable defects in its integrity and its relevance in formal repair when rectocele is operated upon as the principal condition in patients with intractable evacuatory difficulty.

DISCUSSION

The investigation and surgical management of rectocele is controversial given the relatively small numbers of operated patients in any single specialist unit and the relative lack of prospective data concerning functional outcome in operated cases. The imaging of rectocele patients is currently in a state of change, and the newer diagnostic modalities including dynamic magnetic resonance imaging frequently display a multiplicity of pelvic floor disorders. When surgery is indicated, coloproctologists most commonly utilize an endorectal defect-specific repair, but there are few controlled randomized data regarding outcome and response criteria of specific symptoms with particular surgical approaches. A Medline-based literature search was conducted for this review to assess the clinical results of defect-specific rectocele repairs using the endorectal, transvaginal, transperineal, or combined approaches. Only the studies are included that report both pre- and postoperative symptoms including constipation, evacuatory difficulty, pelvic pain, the impression of a pelvic mass, fecal incontinence, dyspareunia or the need for assisted digitation to aid defecation.

CONCLUSION

The history of rectocele repair, its clinical and diagnostic features and the advantages, disadvantages and indications for the different surgical techniques are presented in this review. Suggested diagnostic and surgical therapeutic algorithms for management have been included. It is recommended that a multicenter controlled randomized trial comparing surgical approaches for symptomatic evacuatory dysfunction where rectocele is the principal abnormality should be conducted.

Clinical and physiological findings, and possible aetiological factors of rectal hyposensitivity

BACKGROUND

Rectal hyposensitivity (RH) relates to insensitivity of the rectum on anorectal physiological investigation and appears common in functional bowel disorders. The clinical significance of this physiological abnormality is unclear.

METHOD

RH was defined as one or more sensory threshold volumes raised beyond the normal range (mean plus two standard deviations) on rectal balloon distension. Clinical information and results of other anorectal physiological investigations were evaluated in 261 patients with RH.

RESULTS

Patients with RH most commonly presented with constipation (48 per cent), constipation and incontinence in combination (27 per cent), or faecal incontinence (20 per cent). Thirty-eight per cent of patients had a history of previous pelvic surgery, 22 per cent a history of anal surgery and 13 per cent a history of spinal trauma. In patients with RH presenting with symptoms of constipation or incontinence, impaired rectal sensation was the only abnormality on physiological investigation in 48 per cent and 31 per cent respectively.

CONCLUSION

Patients with RH display marked heterogeneity in terms of presenting symptoms. The exact causes of RH are unknown, but there is evidence to suggest that pelvic nerve injury and spinal trauma are possible aetiological factors. RH appears important in the aetiology of both constipation and faecal incontinence, and may be useful as a predictor of surgical outcome.

Surgical treatment of constipation and fecal incontinence

Fecal incontinence is a disabling and distressing condition. Many patients are reluctant to discuss the condition with a physician. A thorough history, good physical examination, and detailed anorectal physiologic investigations can help in the therapeutic decision-making algorithm. Patients with isolated anterior sphincter defects are candidates for overlapping repair. In the presence of unilateral or bilateral pudendal neuropathy, the patient should be counseled preoperatively regarding a [table: see text] lower anticipation of success. If the injury occurred shortly before the planned surgery and neuropathy is present, it may be prudent to wait because neuropathy sometimes can resolve within 6 to 24 months of the injury. Pudendal nerve study may help determine surgical timing. An anterior sphincter defect combined with a rectovaginal fistula can be approached by overlapping sphincter repair and a concomitant transanal advancement flap. Patients who had undergone multiple such procedures may benefit from concomitant fecal diversion at the time of repeat sphincter repair. Patients with global or multifocal sphincter injury may be candidates for a neosphincter procedure. The stimulated graciloplasty and artificial bowel sphincter are reasonable options. In the absence of the availability of these techniques or because of financial constraints, consideration could be given to bilateral gluteoplasty or unilateral or bilateral nonstimulated graciloplasty. The postanal repair still serves a role in patients with isolated decreased resting pressures with or without neuropathy or external sphincter injury with minimal degrees of incontinence. Biofeedback and the Procon device may play a role in these patients. Lastly, fecal diversion must be considered as a means of improving the quality of life because the patient can participate in the activities of daily living without the fear of fecal incontinence.

Rectal augmentation and stimulated gracilis anal neosphincter: a new approach in the management of fecal urgency and incontinence

PURPOSE

The aim of this study was the development of a procedure which would successfully treat selected patients presenting with incapacitating urgency and fecal incontinence. Some patients presenting with urgency and fecal incontinence, with an intact anorectum but deficient sphincter mechanism, have low rectal compliance. Management is problematic, because correction of the sphincter defect does not abolish the incapacitating urgency caused by rectal hypersensitivity.

METHODS

This was a prospective study of three female patients with urgency and fecal incontinence who underwent combined rectal augmentation using a segment of distal ileum and stimulated gracilis anal neosphincter. All patients had low rectal volumes and two exhibited a temporal relationship between high-amplitude (>60 mmHg) rectal pressure waves and urgency on prolonged ambulatory anorectal manometry.

RESULTS

Urgency was abolished and continence restored in all individuals. When the level of stimulation was not optimal or had been discontinued, patients experienced only passive incontinence with no urgency. Postoperative physiology revealed elevated thresholds to rectal distention and a reduction in the number of high-amplitude rectal pressure waves in all cases.

CONCLUSIONS

Combined rectal augmentation with stimulated gracilis anal neosphincter may be of benefit to some patients with distressing urgency and fecal incontinence not previously helped by current techniques.

Vertical reduction rectoplasty: a new treatment for idiopathic megarectum

BACKGROUND

The aetiology of idiopathic megarectum is unknown and the results of surgery are often unsatisfactory. Rectal hyposensation is common and poor perception of rectal filling may contribute to the poor evacuatory function. By reducing the capacity of the rectum, it was hypothesized that sensory thresholds to rectal distension and perception of urge to defaecate would be improved.

METHODS

Vertical reduction rectoplasty (VRR) and concomitant sigmoid colectomy was performed on six patients with idiopathic megarectum. Patients were evaluated before and after operation by detailed questionnaire and anorectal physiology. Postoperative rectal compliance was also studied by means of a programmable electronic barostat. Where appropriate, physiological data were compared with those obtained in eight healthy volunteers.

RESULTS

Bowel frequency increased from a preoperative median of 2.5 to 16 per month after operation. Four patients reported improved rectal perception of the urge to defaecate. Thresholds for defaecatory urge and maximum tolerated volume were significantly reduced following VRR (P<0.05). Post-VRR rectal compliance was no different from that in healthy volunteers. Colonic transit time decreased significantly after VRR (P<0.05) and evacuation on proctography increased from a median of 30 per cent to 50 per cent. At a median of 57 weeks' follow-up five of the six patients expressed continued satisfaction with the results.

CONCLUSION

VRR is a new approach to the treatment of idiopathic megarectum. Clinical and physiological studies confirm that it can improve sensory feedback and defaecation. The procedure needs further evaluation as the number of patients undergoing the procedure increases.

Pelvic floor study in patients with obstructive defecation: influence of biofeedback

The aim of this study was to evaluate the pathophysiologic abnormalities in patients with obstructive defecation or dyssynergia and to assess the role of biofeedback treatment. Three groups were studied. Group A had 24 patients with obstructive defecation; B, 25 patients with constipation; and C, 22 healthy volunteers. Rectosigmoid segmental transit time of group A was 28.5 hours (SD +/- 13.4); B, 17.2 hours (SD +/- 11.5); and C, 8.5 hours (SD +/- 6.3) (p < 0.05). There was no statistical difference in resting and squeezing anal pressure among the three groups. Anorectal angle at rest revealed no difference among the three groups. At strain, a statistically significant difference between groups A and C (p < 0.05) and a marginal difference between groups A and B was noted. Rectocele of the anterior rectal wall was present at strain in 17/24 patients of group A and 7/22 patients of group C (p < 0.05). Electromyography during strain revealed abnormal contractions of puborectalis muscle and external anal sphincter, in 13 and 14 patients of group A, respectively, which differed from that observed in groups B and C (p < 0.001). Biofeedback treatment was applied with good results in 7 of 11 patients of group A. At six months, constipation relapsed in only one of treated patients. Patients suffering from obstructive defecation seem to have slower rectosigmoid transit time than the others. Defecography shows smaller anorectal angle at strain and rectocele of the anterior rectal wall more often. Abnormal pelvic floor contraction at strain is often noted in anal electromyography. Some of these patients seem to respond favorably to biofeedback treatment.

Slow-transit constipation: solitary symptom of a systemic gastrointestinal disease

INTRODUCTION

Autonomic neuropathy is thought to play a role in the pathogenesis of slow-transit constipation, but other gastrointestinal organs may also be involved, even if they are symptom-free. We investigated whether motility in gastrointestinal organs other than the colon was impaired in patients with slow-transit constipation and whether the autonomic nervous system was involved.

METHODS

Twenty-one consecutive patients (18 females; median age, 46 years) with severe chronic constipation (< or = 2 defecations/week and delayed colonic transit time) were studied. Autonomic neuropathy function was tested with esophageal manometry, gastric and gallbladder emptying (fasting and postprandial motility) by ultrasonography, orocecal transit time (H2-breath test), colonic transit time (radiopaque markers), and anorectal volumetric manometry. The integrity of the autonomic nervous system was assessed by a quantitative sweat-spot test for preganglionic and postganglionic fibers, tilt-table test, and Valsalva electrocardiogram R-R ratio.

RESULTS

Esophageal manometry showed gastroesophageal reflux or absence of peristalsis in five of the seven patients examined. Gallbladder dysmotility (i.e., increased fasting, postprandial residual volume, or both) was observed in 6 of 14 (43 percent) patients. Gastric emptying was decreased in 13 of 17 (76 percent) patients. Orocecal transit time was delayed in 18 of 20 (90 percent) patients; median transit time was 160 (range, 90-200) minutes. Median colonic transit time was 97 (range, 64-140) hours. Anorectal function showed abnormal rectoanal inhibitory reflex and decreased rectal sensitivity in 11 of 19 (58 percent) patients. Signs of autonomic neuropathy of the sympathetic cholinergic system were found in 14 of 18 (78 percent) patients. Only one of nine patients had vagal abnormalities detected with the Valsalva test and four of five patients with a history of orthostatic hypotension had a positive tilt-table test.

CONCLUSIONS

Slow-transit constipation may be associated with impaired function of other gastrointestinal organs. More than 70 percent of patients with slow-transit constipation present some degree of autonomic neuropathy. Severe constipation may be the main complaint in patients with a systemic disease involving several organs and possibly involving the autonomic nervous system. This should be considered in the management of such cases.

Paradoxical sphincter reaction is influenced by rectal filling volume

PURPOSE

Paradoxical sphincter reaction is frequently found in constipated patients but sometimes also in incontinent patients and in asymptomatic subjects. Its significance in defecation disorders has, therefore, been debated. The aim of the present study was to investigate whether paradoxical sphincter reaction is influenced by rectal filling volume.

PATIENTS AND METHODS

Eighteen patients with defecation disorders and paradoxical sphincter reaction shown by electromyography were reinvestigated with an extended electromyographic investigation while in the lying position and while in the sitting position, with 50-ml, 100-ml, and 150-ml water-filled rectal balloons.

RESULTS

All 18 patients showing paradoxical sphincter reaction in the first investigation also showed the reaction at the second investigation in the lying position with a 0-ml volume of rectal contents. In the sitting position, with a volume of 150 ml of rectal contents, the increase in electromyographic activity disappeared in seven patients (39 percent) and no longer showed paradoxical sphincter reaction. Electromyography showed decreased activity in one patient and unchanged activity in six patients during straining. A closing reflex was seen after completed straining in all of these seven patients.

CONCLUSIONS

The present study demonstrates that paradoxical sphincter reaction diagnosed by electromyography is influenced by the rectal filling volume and might diminish when the rectum is filled with contents. The conventional electrophysiologic technique in the diagnosis of paradoxical sphincter reaction might, therefore, overdiagnose this condition.

Anismus: fact or fiction?

PURPOSE

Although anismus has been considered to be the principal cause of anorectal outlet obstruction, it is doubtful whether contraction of the puborectalis muscle during straining is paradoxical. The present study was conducted to answer this question.

METHODS

During the first part of the study, we retrospectively reviewed 121 patients with constipation and/or obstructed defecation (male:female, 10/111; median age, 51 years). All of these patients underwent electromyography (EMG) of the pelvic floor and the balloon expulsion test (BET) in the left lateral position. Evacuation proctography was performed in all of these patients in the sitting position. Both the posterior anorectal angle and the central anorectal angle were measured. EMG and BET were also performed in ten controls (male:female, 4/6; median age, 47). In 147 patients with fecal incontinence (male:female, 24/123; median age, 58) only EMG activity was recorded. Criteria for anismus during straining were increase or insufficient (<20 percent) decrease of EMG activity, failure to expel an air-filled balloon on BET, and decrease or insufficient (<5 percent) increase of anorectal angle on evacuation proctography. Between June 1994 and March 1995, we conducted a second prospective study in a consecutive series of 49 patients with constipation and/or obstructed defecation and 28 patients with fecal incontinence. Both groups were compared with 19 control subjects. In this study, all three tests were performed. EMG and BET were performed both in the left lateral position and in the sitting position.

RESULTS

The retrospective study was undertaken by comparing the constipated patients with the incontinent patients and the controls, and the anismus detected by EMG was found in, respectively, 60, 46, and 60 percent. Failure to expel the air-filled balloon was observed in 80 constipated patients (66 percent) and in 9 control subjects (90 percent). Based on posterior anorectal angle and central anorectal angle measurements, anismus was diagnosed in, respectively, 21 and 35 percent of constipated patients. In the prospective study, none of the tests showed significant differences regarding the prevalence of anismus between the two subgroups of patients and the control subjects. The prevalence of anismus only differed between constipated and incontinent patients when the diagnosis was based on BET in the sitting position (67 vs. 32 percent; P < 0.005). Our study shows that contraction of the puborectalis muscle during straining is not exclusively found in patients with constipation and/or obstructed defecation. The three tests most commonly used for the diagnosis of anismus showed an extremely poor agreement.

CONCLUSION

Based on these findings, we doubt the clinical significance of anismus.

[Defecation flowmetry. A new study technique for evaluating the evacuation function of the rectum]

In a prospective study carried out on 78 patients with chronic constipation (31, with slow transit, 47 with obstructive defecation disorders) the evacuation function of the rectum during defecation was assessed by defecoflowmetry. These patients were compared to a control group of normal volunteers (n = 32). The following parameters were evaluated: defecation and retention volume, defecation fraction, defecation time, maximum flow, mean flow rate and time to maximum flow. As expected, there was no difference in evacuation function between the group of patients with slow transit and the control group. Significant differences, however, existed between the two types of constipation, as well as between obstructive defecation disease and controls, regarding all parameters mentioned above. Evacuation function depends neither on rectal neck pressure nor on intrarectal pressure. In patients with obstructive defecation disorders, three subgroups were discernable: one with prolonged time of defecation and satisfactory evacuation, one with prolonged time of defecation and poor evacuation, and one small group of patients who were not able to defecate. Each group is based on a different underlying pathomechanism. We conclude that changes in evacuation function of the rectum refer either to volume or to time of defecation, or to both. Changes are found only in obstructive type constipation, not in slow transit constipation. Therefore, defeconflowmetry as a dynamic procedure can be used in screening for the classification of chronic constipation.

Clinical and physiologic effects of biofeedback in outlet obstruction constipation

PURPOSE

We report the results of biofeedback (BF) on patients with outlet obstruction defecation (OOC), including those with and without measurable paradoxical puborectalis contractions (PP). Clinical and anorectal physiologic parameters (ARP) were assessed one week before and after a standardized course of BF.

METHODS

Sixty-two consecutive patients (24 men, 38 women; mean age, 48 (standard error of the mean, 2.3) years) were recruited. All had persistent constipation despite six weeks of dietary fiber supplements. Colonic inertia was excluded by transit marker studies. Defecating proctography excluded anatomic abnormalities causing outlet obstruction. Patients underwent four outpatient sessions of biofeedback, each session lasting one hour.

RESULTS

After BF, 56 patients (90.3 percent) were subjectively improved. Frequency of spontaneous bowel movements were significantly increased (P = 0.003). Frequency of laxative-induced (P = 0.004) and enema-induced (P = 0.005) stools were reduced. Anal resting (P = 0.04) and squeeze (P = 0.002) pressures were increased. Number of patients with PP was reduced from 40 to 31 (P = 0.004). Presence of PP did not affect response to BF. There were no differences in ARP between the 56 patients who improved and the 6 who did not. There were no side effects or clinical regressions after a mean follow-up of 14.9 (standard error of the means, 0.9) months.

CONCLUSIONS

BF effectively treated OOC in 90.3 percent, regardless of PP. Anal pressures were increased, and PP was decreased.

Anorectal and pelvic floor function. Relevance of continence, incontinence, and constipation

Anorectal tests need to be tailored to the presentation of the individual patient. Clearly the tests are most useful when they identify anatomic or physiologic abnormalities for which there are successful treatments. For the incontinent patient, anal manometry is the most useful test. Sphincter injuries should be repaired, whereas neurogenic incontinence is best treated initially with biofeedback. Three tests are more useful for the constipated patient: colonic transit time, degree of pelvic floor descent on straining, and balloon expulsion. Colonic inertia responds to total colectomy and pelvic floor dysfunction to biofeedback. Meanwhile, patients with irritable bowel syndrome require rereferral back to their physicians.

Anorectal angle enhances faecal continence

This study was performed with an in vitro model to assess the relative importance of sphincter pressure and anorectal angulation in maintaining faecal continence. Water and semisolid material were infused separately into porcine intestine compressed by an inflatable cuff until leakage was observed. Angulation of the bowel with respect to the cuff was 180 degrees and then 90 degrees. With water, holdback pressure was independent of angulation. In contrast, when semisolid material was used, angling the bowel to 90 degrees increased holdback pressure by at least 100 per cent. Measurements taken in solid tubes demonstrated that both a restriction in the tube and an unconstricted 90 degrees bend produced a resistance to flow of the semisolid material which was dependent on flow rate. These data suggest that liquid is retained in the rectum by occlusion pressure alone, whereas the retention of semisolid material is enhanced by angulation.

Electrically stimulated colonic reservoir for total anorectal reconstruction

Total anorectal reconstruction after abdominoperineal excision of the rectum has failed to achieve perfect continence. Electrically stimulated reservoir evacuation in combination with an electrically stimulated gracilis neoanal sphincter might improve results. A J pouch was constructed in an isolated colonic loop of seven dogs. Bipolar square wave pulses were delivered via two intramural stainless steel electrode pairs at 10 Hz. Stimulation parameters were varied to achieve adequate contraction. Serosal strain gauges recorded spontaneous and stimulated pouch motility. Evacuation was quantified by a volume displacement technique and observed fluoroscopically. Recordings were performed for a median of 3 (range 1-11) months. At 10 Hz and 0.5 ms pulse width, stimulation was required for 2 min and at voltages of 15 V (n = 4), 18 V (n = 1) and 20 V (n = 2) to obtain a contraction of amplitude comparable to that of a spontaneous contraction. Suprathreshold stimulation invariably resulted in colonic pouch contraction. The mean(95 per cent confidence interval (c.i.)) stimulus-response latency was 25.5(1.9) s. The mean(95 per cent c.i.) intraluminal pressure generated during stimulation was 114.1(17.0) cmH2O and 64.6(12.0) cmH2O during spontaneous activity (P < 0.001). In conclusion, electrical stimulation via intramural electrodes produced contraction generating sufficient intraluminal pressure to effect evacuation of a canine colonic pouch. This has potential for incorporation with an electrically stimulated neoanal sphincter in total anorectal reconstruction to improve evacuation and continence.

Obstructed defecation: current status of pathophysiology and management

Obstructed defecation poses a challenging clinical problem and in many patients presenting with this syndrome the underlying pathophysiology cannot be determined. Up to now, attempts to diagnose and treat obstructed defecation (anismus) have focused on the function of the somatic pelvic floor musculature surrounding the anorectum, and concepts such as 'puborectalis paradox' and 'spastic pelvic floor' have gained widespread acceptance despite there being no objective data to support such concepts. New evidence showing that defecation is an integrated process of colonic and rectal emptying suggests that anismus may be much more complex than a simple disorder of the pelvic floor muscles. In a small number of patients obstructed defecation is caused by a more simple mechanism, such as internal sphincter hypertonia or a large rectocele, which is easily corrected surgically. Careful selection of patients for treatment, based on identifying the underlying pathophysiological disorder, is emphasized.

Scintigraphic assessment of colonic function during defaecation

The aim of this study was to develop a method by which rectal and colonic activity could be examined during defaecation under physiological conditions, in order to evaluate whether the colon plays a role in defaecation. Subjects presented to the Nuclear Medicine department on the day following ingestion of oral In-111 labelled DTPA, when they developed the normal urge to defaecate. Defaecation took place in a private room while dynamic scintigraphy of the rectum and colon was recorded. Fourteen subjects were studied (8 normal subjects, 4 with constipation, 2 with irritable bowel syndrome). In 13 subjects the left colon was visualized during defaecation and emptying was clearly observed in 12. The right colon was visualised in 11 subjects and emptying was seen in 7. Mean percentage segmental evacuation was right colon 20%, left colon 32% and rectum 66%. Colonic emptying occurs during defaecation, which is not a process of rectal evacuation only. This has implications for the understanding of the pathophysiology of obstructed defaecation.

Anorectal function

A review in a historic perspective of the present knowledge of anorectal physiology is presented. The techniques used in the anorectal physiology laboratory are discussed. Application of new sophisticated techniques to anorectal physiology research in recent years continue to improve our knowledge of anorectal function. Anal continence and defecation depend on both the anal sphincter and the rectum. The assessment of patients with functional anorectal diseases should include a more complete physiologic evaluation of the anorectum than used previously.

Physiological and histochemical adaptation of the electrically stimulated gracilis muscle to neoanal sphincter function

The physiological and histochemical characteristics of the gracilis muscle were studied in 19 patients undergoing electrically stimulated gracilis neosphincter construction. Indications for surgery were faecal incontinence (n = 11) and reconstruction following sphincter excision or congenital absence (n = 8). Transposition of the gracilis muscle around the anal canal followed by chronic low-frequency electrical stimulation was associated with a shift in the frequency-response curve and a prolongation of the time-course of individual muscle twitches suggestive of transformation to a slow-twitch fatigue-resistant type. Temporary cessation of electrical stimulation resulted in a reversal of the frequency-response changes. Muscle biopsies taken before and a median of 80 (range 49-137) days after transposition and low-frequency electrical stimulation indicated a significant increase in the proportion of type 1 fibres and a significant decrease in their diameter. These results show that the human gracilis muscle is capable of physiological and histochemical adaptation to long-term neosphincter function.

Anorectal manometry in the diagnosis of paradoxical puborectalis syndrome

This prospective study was undertaken to compare the utility of anorectal manometry (ARM) with that of anal electromyography (EMG) and cinedefecography (CD) in the diagnosis of paradoxical puborectalis syndrome (PPS). One hundred sixteen consecutive patients with a history of chronic constipation were prospectively assessed. These 35 males and 81 females were of a mean age of 60 years, ranging from 18 to 84 years. The incidences of PPS were 63 percent for ARM, 38 percent for EMG, and 36 percent for CD. The correlations of PPS were suboptimal: ARM and EMG, 70 percent; and ARM and CD, 61 percent. A two-tiered system for the manometric classification of PPS was developed. First, the evacuation pressure curve pattern was classified as a normal relaxed downward (Type A; n = 43), a nonrelaxed flat or equivocal (Type B; n = 36), and a paradoxical upward (Type C; n = 37). PPS was noted with increasing incidence within curve types (21 percent in Type A, 64 percent in Type B, and 95 percent in Type C). Second, an evacuation index (EI = evacuation pressure/squeeze pressure) was defined: Group I (EI < 0; n = 43), Group II (0 < or = EI < 0.25; n = 24), Group III (0.25 < or = EI < 0.5; n = 27), and Group IV (EI > or = 0.5; n = 18). The finding of PPS also correlated with the EI group: 21 percent in Group I, 67 percent in Group II, 74 percent in Group III, and 100 percent in Group IV. This subdivision of curve types and EI groups may provide a role in the diagnosis of PPS.

Electromyography of the pubococcygeus muscles in patients with obstructed defaecation

The function of the pubococcygeus muscles during defaecation straining was compared in 10 women with obstructed defaecation and 12 age-matched control subjects. Video-proctography in each patient showed failure to evacuate the rectum and sagging of the pelvic floor during attempted defaecation. Trans-perineal concentric needle electromyography in the puborectalis muscle and transvaginal electromyography in the pubococcygeus muscle was carried out during defaecation straining and during attempted rectal balloon expulsion. Contraction of the pubococcygeus muscle was observed in 10 of the 12 control subjects and in 2 of the 10 patients with obstructed defaecation (P < 0.005). Virtually equal proportions of subjects in each group showed relaxation or contraction of the puborectalis muscle during straining. There was significant perineal descent on straining in the patient group (P = 0.005). This group of patients with obstructed defaecation showed failure of the pubococcygeus muscles to contract, perhaps due to neuropathic weakness of the muscles. The puborectalis muscle did not cause obstructed defaecation in these patients, and the concept of "paradoxical" contraction of this muscle is questioned.

Detection of subclinical autonomic neuropathy in constipated patients using a sweat test

Chronic idiopathic constipation may be the result of an autonomic neuropathy. This hypothesis was tested in 23 constipated patients and 17 age matched controls, using the acetylcholine sweat spot test devised to test autonomic integrity in diabetes. Acetylcholine (0.01%) was injected in the dorsum of the foot painted with a mixture of starch and iodine. Active sweat glands appeared on the surface of the skin as small black dots which were photographed and counted, using a grid with 60 subareas. Two measurements were made: the number of dots per unit subarea (sweat spot test score) and the % number of abnormal subareas (with less than six spots). These two parameters were correlated. The median sweat spot test score was 9.53 in patients and 13.92 in controls (p = 0.0001), the receiver operating characteristic curve showing that a score of 12 delimited normal and abnormal subjects. Increasing age was correlated with a low score in patients, probably because of prolonged symptoms. Seventy per cent of patients and one control had a borderline or abnormal number of subareas. These results suggest that idiopathic constipation is associated with a degree of autonomic denervation. The sweat spot test is an easy, inexpensive method to test this hypothesis and deserves a place in the clinical assessment of slow transit constipated patients.

Evidence from dynamic integrated proctography to redefine anismus

The role of anismus in the aetiology of defective rectal evacuation was investigated by dynamic integrated proctography in 20 controls and 71 constipated patients. Normal parameters were defined and compared between 21 constipated patients with poor evacuation during proctography (< 40 per cent of contrast evacuated; group 1) and 50 who evacuated fully (> 90 per cent of contrast evacuated; group 2). Nine patients in group 1 failed to evacuate. Radiological abnormalities of the rectum were recorded in all groups but obstructed evacuation was not observed. Anismus (defined as a recruitment of puborectalis electromyogram (EMG) activity of > 50 per cent) was significantly more common in group 1 than group 2 patients (14 of 21 versus 12 of 50, P < 0.01) and present in seven of those unable to evacuate. Eight patients in group 1 failed to raise intrarectal pressure > 50 cmH2O compared with two in group 2 (P < 0.001). Six patients in group 1 demonstrated both anismus and inability to raise intrarectal pressure, which may combine to cause defective evacuation. EMG recruitment alone is insufficient to diagnose anismus. Definition should be based on three criteria: demonstration of puborectalis EMG recruitment of > 50 per cent; evidence of an adequate level of intrarectal pressure (> 50 cmH2O) on straining; and presence of defective evacuation.

The usefulness of tests in anorectal disease

Specialized tests of anorectal function are designed to complement but not to replace good clinical examination and sound professional judgement. The different methods of recording pressure changes have advantages and disadvantages. Poor correlation exists when data recorded using miniature balloons are compared with data from microtransducers. Prolonged ambulatory monitoring of anal sphincter and rectal pressure reveal that spontaneous transient episodes of sphincter relaxation are demonstrable in normal subjects. In the investigation of patients with possible traction injury to the pudendal nerve, electromyography and pudendal nerve terminal motor latency data are more precise than manometry data. Good correlation between noninvasive surface electromyography using an intra-anal plug electrode and anal manometry can be attained. Mapping of sphincter defects using concentric needle technology is reasonably accurate but distinctly painful. Dynamic defecography readily demonstrates abnormalities of the rectal wall. The division between what is normal and what is clinically relevant is rather imprecise. Comparative studies of sonographic and electromyographic mapping of sphincter defects give good correlation. Recent application of fine hooked electrodes have demonstrated periodic episodes of smooth muscle and sphincter relaxation. The saline infusion test and balloon expulsion test help to accurately quantify the difficulty patients experience in retention or evacuation, respectively. Perineometry is a simple, rapid, noninvasive method of measuring the extent of perineal descent on straining. Although reproducible, it tends to underestimate the degree of descent when compared with the radiological method but it avoids the use of ionized radiation.

Anismus: the cause of constipation? Results of investigation and treatment

Anismus, or failure of the somatic sphincter apparatus to relax at defecation, has been implicated as a major contributor to the problem of obstructed defecation. Current diagnostic methods depend on laboratory measurements of attempted defecation and the most complex, dynamic proctography has been the mainstay of diagnosis. Using a new computerized ambulatory method of recording sphincter function in these patients at home, we report an 80% reduction in our diagnostic rate suggesting that conventional tests fail to accurately diagnose this condition, probably because they poorly represent the natural physiology of defecation. Treatment of this distressing condition is more complex and a variety of surgical and pharmacological measures have failed. Biofeedback retraining of anorectal function of these patients has been very successful and represents the management of choice.

[Electromyography and functional analytic findings in obstructive disorders of defecation. A contribution to the differentiation of neurogenic and myogenic sphincter damage]

The aim of this study was to get further information about functional results in patients with outlet obstruction. We investigated 27 patients (age between 42 and 74 years) by electromyography (EMG), manometry and radiology with contrast-solution. The electromyography, a dynamic investigation method, allows the differentiation between neuronal and muscular malfunctions of the voluntary controlled pelvis muscles. Patients with outlet obstruction should be divided into three groups by EMG diagnosis: One group with neuronal alterations, another group with muscular alterations and one group with neuro-muscular alterations. We obtained marked statistical differences between patients with neuronal or muscular malfunctions in the mean amplitude, the turns per second and the integration of the mean amplitude compared to the control group (14 patients). Patients with only neuronal alterations showed furthermore statistically significant distinctions of the action potential duration from control, whereas the data of patients with muscular malfunctions were significantly different from control in the peak amplitude of the action potentials. 77% of all investigated patients were not able to relax the pelvis muscles during defecation.

How reliable are currently available methods of measuring the anorectal angle?

A prospective study was undertaken to compare two different methods of measuring the anorectal angle (ARA), balloon proctography (BP) and cinedefecography (CD), as well as to evaluate the reproducibility of this measurement using each technique. One hundred four consecutive patients (75 women and 29 men) with constipation (63 patients), fecal incontinence (25 patients), or rectal pain (16 patients) underwent both BP and CD. The ARA was measured by taking lateral radiographs of the pelvis during rest (R), squeeze (S), and push (P). The same interpretation process was performed 2 to 12 months later by the same observer, blinded as to diagnosis and initial measurements. There were highly significant differences in each measurement category, R (P less than 0.0001), S (P less than 0.0001), and P (P less than 0.0004) between BP and CD. However, the correlation between the first and second measurements was excellent (P less than 0.0001). BP was consistently more difficult to interpret because of balloon configuration. Although BP and CD have poor correlation with each other, each examination can be reliably interpreted. CD appears to be a superior examination because of the added ability to delineate rectoceles, intussusceptions, and other structural defects.