Anorectal function

Technical, functional, and oncological validity of robot-assisted total-intersphincteric resection (T-ISR) for lower rectal cancer

BACKGROUND

Few studies fairly compared anorectal function and prognostic outcomes between patients undergoing abdominoperineal resection (APR) and anorectal-function-saving operations (ASO) under the equivalent conditions. By contrast, surgeons used to be somewhat hesitant to conduct total intersphincteric resection (T-ISR) as maximal ASO, due to its technical complexity and potential anorectal dysfunction.

METHODS

Propensity-score matched cohorts undergoing robot-assisted R0 surgery [T-ISR vs APR vs partial-subtotal ISR (PS-ISR)/lower anterior resection (LAR)] for rectal cancer (n = 1361) were included. Operative outcomes, recurrence, and disease-free/overall survival (DFS/OS) were analyzed. Anorectal function was evaluated based on fecal incontinence score and high-resolution manometry between the T-ISR and other ASO groups.

RESULTS

Few differences were detected between the T-ISR and APR groups. More patients undergoing APR had T4 stage disease, while the lowest tumor margin was the same in both groups (mean, 1.5 cm from anal verge). Prognostic outcomes did not differ between the T-ISR and APR groups, including local (5.1% vs 7.7%, p = 1) or systemic (15.4% vs 25.6%, p = 0.401) recurrence, and 5-year DFS (78.7% vs 61.5%, p = 0.1) and OS (89% vs 82.1%, p = 0.434) rates, nor were there differences between the T-ISR and PS-ISR/LAR groups. The PS-ISR group generally showed less anorectal dysfunction than the T-ISR group, but maximal tolerance volume did not differ between these two groups and was within the range for the healthy population.

CONCLUSIONS

T-ISR can replace most traditional APR, except for advanced T4 disease with aggressive infiltration into the levator-sphincters, and can provide tolerable anorectal dysfunction.

Faecal incontinence in adults

Faecal incontinence, which is defined by the unintentional loss of solid or liquid stool, has a worldwide prevalence of ≤7% in community-dwelling adults and can markedly impair quality of life. Nonetheless, many patients might not volunteer the symptom owing to embarrassment. Bowel disturbances, particularly diarrhoea, anal sphincter trauma (obstetrical injury or previous surgery), rectal urgency and burden of chronic illness are the main risk factors for faecal incontinence; others include neurological disorders, inflammatory bowel disease and pelvic floor anatomical disturbances. Faecal incontinence is classified by its type (urge, passive or combined), aetiology (anorectal disturbance, bowel symptoms or both) and severity, which is derived from the frequency, volume, consistency and nature (urge or passive) of stool leakage. Guided by the clinical features, diagnostic tests and therapies are implemented stepwise. When simple measures (for example, bowel modifiers such as fibre supplements, laxatives and anti-diarrhoeal agents) fail, anorectal manometry and other tests (endoanal imaging, defecography, rectal compliance and sensation, and anal neurophysiological tests) are performed as necessary. Non-surgical options (diet and lifestyle modification, behavioural measures, including biofeedback therapy, pharmacotherapy for constipation or diarrhoea, and anal or vaginal barrier devices) are often effective, especially in patients with mild faecal incontinence. Thereafter, perianal bulking agents, sacral neuromodulation and other surgeries may be considered when necessary.

Fecal incontinence in nonpregnant nulliparous women aged 25 to 64 years-a randomly selected national cohort prevalence study

BACKGROUND

The extent to which fecal incontinence is associated with obstetrical history or pelvic floor injuries is still a controversial and unresolved issue. One crucial first step toward answering this question is the need to study fecal incontinence in nonpregnant, nulliparous women.

OBJECTIVE

The aim of this study was to present detailed, descriptive measures of the accidental leakage of liquid or solid stool and gas in a randomly selected, large national cohort of nonpregnant, nulliparous women aged 25 to 64 years.

STUDY DESIGN

The Swedish Total Population Register identified the source population. Four independent, age-stratified, simple random samples in a total of 20,000 nulliparous women aged 25 to 64 years were drawn from 625,810 eligible women. Information was collected in 2014 using postal and web-based questionnaires. The 40-item questionnaire included questions about the presence and frequency of the leakage of solid and liquid stool and gas, which provided the basis for the generic terms fecal and anal incontinence. Statistical analyses of the differences between the groups were performed using the Fisher's exact test for dichotomous variables and the Mann-Whitney U-test for continuous variables. The trend between >2 ordered categories of dichotomous variables was analyzed with Mantel-Haenszel statistics. When analyzing the trend between multiple ordered vs nonordered categorical variables, the Kruskal-Wallis test was used. The age-related probability and risk increase per 10 years for incontinence parameters was calculated from logistic regression models adjusted for body mass index.

RESULTS

The study population was 9197 women, and the response rate was 52.2%, ranging from 44.7% in women aged 25 to 34 years to 62.4% among those from 55 to 64 years. All the types of incontinence, except severe isolated gas incontinence, increased with age up to 64 years. The estimated probability of fecal incontinence was 8.8% at age 25 years and 17.6% at age 64. The leakage of liquid stool was dominant, occurring in 93.1% (95% confidence interval, 91.4-94.5) of the women with fecal incontinence, whereas leakage of solid stool occurred in 33.9% (95% confidence interval, 31.1-36.7), of which approximately 80% also had concomitant leakage of liquid stool. The leakage of liquid stool increased markedly up to age 65, whereas the increase in the isolated leakage of solid stool was negligible across all ages (overall <0.4%). Liquid and solid stool, separate or in combination, co-occurred with gas in approximately 80%. The distribution pattern of the different types of leakage, single or combined, was similar in all the age groups. Both age and body mass index (kg/m²) were risk factors for fecal incontinence (P<.0001), with an interaction effect of P=.16.

CONCLUSION

Abnormal stool consistency has been identified as the strongest risk factor for accidental bowel leakage. The same pattern characterized by a dominance of liquid stool and gas leakage, prevalent concomitant leakage of solid and liquid stool, and a negligible rate of isolated leakage of solid feces was observed across all ages. The low rates of isolated leakage of solid stool support the impression that dysfunction of the continence mechanism of the pelvic floor had a negligible role for bowel incontinence, which is essential information for comparison with women with birth-related injuries.

Pain relieving effect of music on patients during transrectal ultrasonography: A pilot study

Background

Patient discomfort is often inevitable during transrectal ultrasonography (TRUS), a widely used modality for evaluating benign prostate hyperplasia/lower urinary tract symptoms. Music has been suggested as a method of pain relief during urologic procedures. In this study, we investigated the effect of music on pain relief during TRUS.

Methods

In a pilot study conducted from March to June 2019, pain scores of 316 patients who underwent TRUS with or without music were quantified using the visual analog scale (VAS). One-to-one propensity score matching was performed by matching the subjects between the groups. Patients with hemorrhoids of grade ≥ III were excluded (n = 4).

Results

Among the 312 patients included in the study (VAS score = 3.3 ± 2.4), 177 listened to music during the procedure. There were significant differences in age, prostate-specific antigen, prostate volume, International Prostate Symptom Score symptom/life score, and VAS score between the music (+) and music (−) groups. After adjusting for relevant variables, VAS scores were significantly lower in male patients aged ≥65.0 years who underwent music intervention than in those who did not (1.5 ± 1.4 vs. 3.0 ± 1.4, p = 0.002).

Conclusion

Age was negatively associated with pain during TRUS, and music had a relieving effect on pain in patients aged ≥65.0 years. Our findings may help improve the quality of examinations in urologic outpatient offices.

The evaluation of the effect of vaginal delivery and aging on anal sphincter anatomy and function

OBJECTIVE

This study was conducted to evaluate the effect of vaginal delivery and aging on anal sphincter anatomy and function.

METHOD

Asymptomatic thirty women were included in this prospective study. Group 1 included 10 women (age range: 18-50) who had never been pregnant. Group 2 included 10 women (age range: 18-50) who had vaginal delivery. Group 3 included 10 women over 50 who had vaginal delivery.

RESULTS

There was no statistically significant difference between the three groups in terms of resting and squeeze pressures. It was found that sphincter thickness showed statistically significant difference between the group 1 and group 3, and also group 2 and group 3. There was not statistically significant difference between the group 1 and group 2 in terms of sphincter thickness. There was a positive correlation between the age and sphincter thickness in all groups. In terms of sphincter thickness and pressure findings there was a positive correlation between the squeeze pressure and external anal sphincter thickness only in group 3.

CONCLUSION

The vaginal delivery did not have a negative influence on the structure and function of the anal sphincter in asymptomatic women. However, it was found that anal sphincter thickness changed strongly in a positive manner with aging.

Intersphincteric Resection Pushing the Envelope for Sphincter Preservation

During the last 15 years, a significant evolution has emerged in the surgical treatment of rectal cancer and restoration of bowel continuity has been one of the main goals. For many years the treatment of distal rectal cancer would necessarily require an abdominoperineal resection and end colostomy. The surgical procedure of intersphincteric resection has been proposed to offer sphincter preservation in patients with low rectal cancer and has been legitimized if executed according to adequate oncologic criteria. This article will discuss the best indications, technical aspects, functional, and oncological outcomes of intersphicteric resection in the management of rectal cancer.

Electrophysiological characterization of human rectal afferents

It is presumed that extrinsic afferent nerves link the rectum to the central nervous system. However, the anatomical/functional existence of such nerves has never previously been demonstrated in humans. Therefore, we aimed to identify and make electrophysiological recordings in vitro from extrinsic afferents, comparing human rectum to colon. Sections of normal rectum and colon were procured from anterior resection and right hemicolectomy specimens, respectively. Sections were pinned and extrinsic nerves dissected. Extracellular visceral afferent nerve activity was recorded. Neuronal responses to chemical [capsaicin and "inflammatory soup" (IS)] and mechanical (Von Frey probing) stimuli were recorded and quantified as peak firing rate (range) in 1-s intervals. Twenty-eight separate nerve trunks from eight rectums were studied. Of these, spontaneous multiunit afferent activity was recorded in 24 nerves. Peak firing rates increased significantly following capsaicin [median 6 (range 3-25) spikes/s vs. 2 (1-4), P < 0.001] and IS [median 5 (range 2-18) spikes/s vs. 2 (1-4), P < 0.001]. Mechanosensitive "hot spots" were identified in 16 nerves [median threshold 2.0 g (range 1.4-6.0 g)]. In eight of these, the threshold decreased after IS [1.0 g (0.4-1.4 g)]. By comparison, spontaneous activity was recorded in only 3/30 nerves studied from 10 colons, and only one hot spot (threshold 60 g) was identified. This study confirms the anatomical/functional existence of extrinsic rectal afferent nerves and characterizes their chemo- and mechanosensitivity for the first time in humans. They have different electrophysiological properties to colonic afferents and warrant further investigation in disease states.

A novel retrieval technique for large colorectal tumors resected by endoscopic submucosal dissection: tumor extraction by defecation

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) has been developed to facilitate en bloc resection of large lesions. However, it is laborious to retrieve the large colorectal specimens. We propose a novel retrieval technique using a Valsalva maneuver, known as Tumor Extraction by Defecation (TED).

CASE SERIES

A total of nine lesions (median size 88 mm, maximum 225 mm; proximal colon three, rectum six) that could not be easily retrieved using net forceps were subsequently removed by TED. The rectum was filled with water through the colonoscope. The patient then strained to evacuate the specimen, facilitated by an almost straight anorectal angle. All specimens were retrieved without fragmentation, within minutes. Histology was assessed appropriately, including an adenoma in two and mucosal cancer in seven. All cut margins were verified to be negative. No adverse events occurred.

CONCLUSIONS

TED is a promising technique for retrieving large colorectal specimens after ESD.

Anorectal incontinence: a challenge in diagnostic and therapeutic approach

Anorectal incontinence is a symptom of a complex multifactorial disorder involving the pelvic floor and anorectum, which is a severe disability and a major social problem. Various causes may affect the anatomical and functional integrity of the pelvic floor and anorectum, leading to the anorectal continence disorder and incontinence. The most common cause of anorectal incontinence is injury of the sphincter muscles following delivery or anorectal surgeries. Although the exact incidence of anorectal incontinence is unknown, various studies suggest that it affects ~2.2-8.3% of adults, with a significant prevalence in the elderly (>50%). The successful treatment of anorectal incontinence depends on the accurate diagnosis of its cause. This can be achieved by a thorough assessment of patients. The management of incontinent patients involves conservative therapeutic procedures, surgical techniques, and minimally invasive approaches.

The physiology of human defecation

Human defecation involves integrated and coordinated sensorimotor functions, orchestrated by central, spinal, peripheral (somatic and visceral), and enteric neural activities, acting on a morphologically intact gastrointestinal tract (including the final common path, the pelvic floor, and anal sphincters). The multiple factors that ultimately result in defecation are best appreciated by describing four temporally and physiologically fairly distinct phases. This article details our current understanding of normal defecation, including recent advances, but importantly identifies those areas where knowledge or consensus is still lacking. Appreciation of normal physiology is central to directed treatment of constipation and also of fecal incontinence, which are prevalent in the general population and cause significant morbidity.

Manometric, sensorimotor, and neurophysiologic evaluation of anorectal function

With advances in diagnostic technology, it is now accepted that in the field of functional bowel disorders, symptom-based assessment is unsatisfactory as the sole means of directing therapy. A robust taxonomy based on underlying pathophysiology has been suggested, highlighting a crucial role for physiologic testing in clinical practice. A wide number of complementary investigations currently exist for the assessment of anorectal structure and function, some of which have a clinical impact in patients with functional disorders of evacuation and continence by markedly improving diagnostic yield and altering management. The techniques, limitations, measurements, and clinical use of manometric, sensorimotor, and neurophysiologic tests of anorectal function are presented.

Transrectal ultrasound, manometry, and pudendal nerve terminal latency studies in the evaluation of sphincter injuries

Fecal incontinence may be due to postpartum anal sphincter injuries or neurological damage even in the absence of obvious perineal trauma. Anal physiologic testing with transrectal ultrasound, manometry, and pudendal nerve terminal latency studies help to identify those patients with anal sphincter injuries who might benefit from anal sphincter repair. In this article, the authors discuss the specific tests that are available and how to interpret them.

Posterior sagittal anorectoplasty in anorectal anomalies: clinical, manometric and profilometric evaluation

CONTEXT AND OBJECTIVE

Anorectal malformations comprise a spectrum of anomalies that continue to be difficult to treat, even today. The aim was to evaluate the fecal continence of children who underwent posterior sagittal anorectoplasty due to anorectal malformations, via computerized anorectal manometry and profilometry.

DESIGN AND SETTING

Prospective study at Universidade Federal de São Paulo.

METHOD

82 patients (56.1% boys; 43.9% girls) of mean age 85.5 months were evaluated. They were divided into continent, partially continent and incontinent groups. Age, sex, manometric variables and profilometric parameters were studied. The results were statistically analyzed.

RESULTS

Among the 82 patients, 37.8% were continent, 25.6% were partially continent and 36.6% were incontinent. The overall mean resting pressure was 22 mmHg, and the means for the continent, partially continent and incontinent groups were, respectively, 30.7 mmHg, 23 mmHg and 14.7 mmHg. The overall mean pressure response to voluntary contraction was 56 mmHg, and the means for the groups were 65.4 mmHg, 55.8 mmHg and 46.6 mmHg, respectively. The rectosphincteric reflex was absent in 82.9% of the cases. In the profilometry analysis for all patients together, blue (20 to 50 mmHg) and yellow (50 to 80 mmHg) were predominant, and there was a similar distribution for the continent and partially continent patients. However, among the incontinent patients, green (< 20 mmHg) and blue prevailed.

CONCLUSIONS

Manometric and computerized profilometric analyses were an excellent method for postoperative evaluations on patients with intermediate and high anorectal anomalies, and for therapeutic planning.

Defining the rectum: surgically, radiologically and anatomically

The terminology used in relation to the rectum varies considerably, added to this there is the subjective nature of clinical assessment and variability in the anatomy of the rectum and anus. It is imperative that definitions are clarified and standardized for use by all members of the multidisciplinary team involved in the care of patients with rectal cancer.

Ano-rectal motility responses to pelvic, hypogastric and pudendal nerve stimulation in the Göttingen minipig

We investigated the effect of efferent stimulation of the pelvic (PN), hypogastric (HGN) and pudendal (PuN) nerves on ano-rectal motility in Göttingen minipigs using an impedance planimetry probe. Changes in the rectal cross-sectional area (CSA) at five axial positions and pressures in the rectum and anal canal were investigated simultaneously. Pelvic nerve stimulation elicited a CSA decrease in the proximal part of the rectum and a simultaneous CSA increase in its distal part. Anal pressure also decreased. Hypogastric nerve and PuN stimulation elicited an increase in anal pressure, but no rectal response. Severing the HGN produced a persistent reduction in resting anal pressure, but no change was observed when the PN and the PuN were severed. Stimulation of the distal part of all three nerves produced a persistent response. Administration of phentolamine and pancouronium eliminated the response to stimulation of the HGN and the PuN, respectively.

CONCLUSION

Rectal responses to PN stimulation vary more than previously suggested. The HGN has an excitatory effect on the internal anal sphincter, and the PuN on the external anal sphincter. However, the PuN plays no major role in maintaining basal anal pressure.

Accidental anal intercourse: does it really happen?

A postal survey was conducted of members of the Association of Forensic Physicians (UK) to determine whether accidental anal intercourse occurs in heterosexual relationships and, if so, whether intoxication by alcohol or drugs and sexual inexperience were likely to be causative factors. Of the 512 (47.9%) replies, there were 498 individuals who had had a previous heterosexual relationship and may have experienced accidental anal intercourse. Of these, there were 26 (7.2%) males and 14 (10.4%) females who reported at least one lifetime episode of accidental anal intercourse. Amongst those with a history of accidental anal intercourse, 79% reported that they were sexually experienced at the time and 83% reported that their partners were sexually experienced. Personal intoxication by alcohol or drugs at the time of accidental anal intercourse was reported by 43%, with 41% reporting that their partners were intoxicated.

Internal anal sphincter: An anatomic study

The anatomy of the internal anal sphincter and surrounding structures was investigated in 24 cadavers using a surgical microscope (6-25 x magnification). An understanding of the anatomy of the internal anal sphincter is helpful in avoiding complications during surgical procedures in the anorectal region. The external anal sphincter was composed of three ellipsoid rings of skeletal muscle (subcutaneous, superficial, and deep) that encircle the anal canal; in contrast, we found that the internal anal sphincter was composed of flat rings of smooth muscle bundles stacked one on top of the other, like the slats of a Venetian blind. In each anal canal, the average number of ring-like slats observed was 26.33 +/- 2.93 (range = 20-30) and each was covered by its own fascia. The smooth muscle fibers and fascia coalesced at three equidistant points around the anal canal to form three columns that extended distally into the lumen and differed in form from the other anal columns. When viewed from an anterior position, the columns were located anteriorly at the observer's right (5 o'clock position), posteriorly at the right (1 o'clock position), and laterally at the left (9 o'clock position). This heretofore unreported anatomy of the internal anal sphincter may play an important role in closing off the lumen of the anal canal and maintaining bowel continence.

Functional magnetic stimulation of the colon in persons with spinal cord injury

OBJECTIVE

To evaluate the usefulness of functional magnetic stimulation (FMS) as a noninvasive method to stimulate the colon in individuals with spinal cord injury (SCI).

DESIGN

A prospective before-after trial consisting of 2 protocols.

SETTING

FMS laboratories of 2 SCI centers.

PARTICIPANTS

Two able-bodied men and 13 men with SCI levels ranging from C3 to L1. Protocol 1 consisted of 9 subjects, 2 of whom were excluded from the analysis. Protocol 2 consisted of 4 subjects.

INTERVENTION

Commercially available magnetic stimulators with round magnetic coils (MCs) were used. Protocol 1 measured the effects of FMS on rectal pressure by placing the MC on the transabdominal and lumbosacral regions. Protocol 2 consisted of a 5-week stimulation period to investigate the effects of FMS on total and segmental colonic transit times (CTTs).

MAIN OUTCOME MEASURE

An increase in rectal pressure and a decrease in CTT by magnetic stimulation.

RESULTS

Data were averaged and the standard error of the mean was calculated. Statistically significant changes in rectal pressure and CTT were also measured. Rectal pressures increased from 26.7 +/- 7.44cmH(2)O to 48.0 +/- 9.91cmH(2)O, p =.0037, with lumbosacral stimulation, and from 30.0 +/- 6.35cmH(2)O to 42.7 +/- 7.95cmH(2)O, p =.0015, with transabdominal stimulation. With FMS, the mean CTT decreased from 105.2 to 89.4 hours, p =.02.

CONCLUSION

FMS is able to stimulate the colon and reduce CTT. FMS is a noninvasive, technological advancement for managing neurogenic bowel in patients with SCI.

Anal vector volume analysis complements endoanal ultrasonographic assessment of postpartum anal sphincter injury

BACKGROUND

The aim of this study was to determine the role of anal vector manometry in the assessment of postpartum anal sphincter injury and to establish the most suitable method of anal vector volume analysis for identifying significant external anal sphincter (EAS) injury in an at-risk parous population.

METHODS

A total of 101 consecutive women with a history of instrumental or traumatic vaginal delivery was recruited. Anal ultrasonography and anal vector manometry were performed. Receiver-operator characteristic curves were used to determine the usefulness of anal manometry and anal vector volume analysis in the identification of significant EAS disruption (full thickness, more than one quadrant involved) detected by ultrasonography.

RESULTS

Seventeen women had significant EAS disruption identified by anal ultrasonography. Anal vector manometry provided complementary functional information. Anal vector symmetry index (VSI), determined by analysis of mean maximum squeeze pressure, yielded 100 per cent sensitivity for significant EAS disruption, with a positive predictive value of 61 per cent.

CONCLUSION

Anal vector manometry complements endoanal ultrasonography. VSI, determined by means of the squeeze pressure profile, correlates best with significant EAS disruption identified at anal ultrasonography.

Postoperative anal canal length predicts outcome in patients having sphincter repair for fecal incontinence

PURPOSE

Controversy exists in regard to the prognostic value of clinical data and physiological tests in patients undergoing sphincter repair for fecal incontinence. The aim of this study was to identify prognostic factors.

METHODS

Between 1986 and 1996, 405 consecutive patients had a sphincter repair for fecal incontinence. Preoperative and postoperative manometric data were available on 51 of these patients, and these patients' charts were reviewed retrospectively. Preoperative and postoperative continence was scored using the four-level scale of Browning and Parks. Mean follow-up was 16.2 (median, 6; range, 1-96) months. Mean age was 41 (median, 36; range, 21-80) years, and 46 (90 percent) patients were female.

RESULTS

Twenty-three (45 percent) patients had perfect continence postoperatively, whereas 41 (80 percent) patients demonstrated improvement in continence score after sphincter repair. Using univariate analysis, various clinical and anal physiologic data were analyzed for an association with postoperative continence score. Postoperative mean resting pressure and postoperative anal canal length were both significantly related to postoperative continence (r(s)B for Spearman correlation coefficient to differentiate from r for the Pearson coefficient. = 0.442; P = 0.0012; and r(s) = 0.440; P = 0.0012, respectively), whereas postoperative mean squeeze pressure was not (r(s) = 0.273; P = 0.0529). Postoperative mean resting pressure and anal canal length were entered into a logistic regression model. Postoperative mean resting pressure was not significant (P = 0.6643), and when it was dropped from the model, postoperative anal canal length was highly significant (estimated odds ratio, 3.2; 95 percent confidence interval, 1.1-9.3; P = 0.0047) in predicting postoperative continence.

CONCLUSIONS

No preoperative data predicted functional outcome, and in contrast to other studies, postoperative anal canal length provides the best prediction of postoperative continence.

Normal pelvic floor physiology

This article outlines the normal physiology of the female pelvic floor, including normal urinary storage and voiding, normal colorectal storage, and defecation. Physiologic changes during a woman's lifetime that may affect bladder and bowel function are also considered. An important framework for understanding the normal physiology of the female pelvic floor is provided, so the reader may gain a more thoughtful approach to the recognition and treatment of pelvic floor pathophysiology.

Sensory and motor dysfunction assessed by anorectal manometry in uterine cervical carcinoma patients with radiation-induced late rectal complication

PURPOSE

To investigate the effects of radiation on anorectal function in patients with carcinoma of the uterine cervix.

METHODS AND MATERIALS

Anorectal manometry was carried out on 24 patients (complication group) with late radiation proctitis. All of the manometric data from these patients were compared with those from 24 age-matched female volunteers (control group), in whom radiation treatment had not yet been performed.

RESULTS

Regardless of the severity of proctitis symptoms, 25% of patients demonstrated all their manometric data within the normal range, but 75% of patients exhibited one or more abnormal manometric parameters for sensory or motor functions. Six patients (25%) had an isolated sensory dysfunction, eight patients (33.3%) had an isolated motor dysfunction, and four patients (16.7%) had combined disturbances of both sensory and motor functions. The maximum tolerable volume, the minimal threshold volume, and the urgent volume in the complication group were significantly reduced compared with those in the control group. The mean squeeze pressure in the complication group was significantly reduced, whereas the mean resting pressure and anal sphincter length were unchanged.

CONCLUSIONS

Physiologic changes of the anorectum in patients with late radiation proctitis seem to be caused by a variety of sensory and/or motor dysfunctions in which many different mechanisms are working together. The reduced rectal reservoir capacity and impaired sensory functions were crucial factors for functional disorder in such patients. In addition, radiation damage to the external anal sphincter muscle was considered to be an important cause of motor dysfunction.

Neurogenic bowel dysfunction after spinal cord injury: clinical evaluation and rehabilitative management

Neurogenic bowel dysfunction (NBD) is one of many impairments that result from spinal cord injury (SCI). The experience of persons with SCI reveals that the risk and occurrence of fecal incontinence and difficulty with evacuation are particularly significant life-limiting problems. This review relates the anatomy and physiology of colon function to the specific pathophysiology that detracts from the quality of life of persons after SCI. There are two patterns of NBD after SCI: the upper motor neuron bowel, which results from a spinal cord lesion above the sacral level, and the lower motor neuron bowel, which results from a lesion to the sacral spinal cord, roots, or peripheral nerve innervation of the colon. Rehabilitation evaluation consists of a comprehensive history and examination to define impairments, disabilities, and handicaps pertinent to NBD. Rehabilitation goals include continence of stool, simple willful independent defecation, and prevention of gastrointestinal complications. Intervention consists of derivation and implementation of an individualized person-centered bowel program, which may include diet, oral/rectal medications, equipment, and scheduling of bowel care. Bowel care is a procedure devised to initiate defecation and accomplish fecal evacuation. Digital-rectal stimulation is a technique utilized during bowel care to open the anal sphincter and facilitate reflex peristalsis. Recent advances in rehabilitation practices, equipment, pharmacology, and surgery have offered patients new bowel program alternatives. Interdisciplinary development of solutions for problems of NBD are evolving rapidly.

Spinal cord injury rehabilitation. 3. Functional outcomes

This self-directed learning module highlights new advances in this topic area. It is part of the chapter on spinal cord injury rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article contains information about mobility, ambulation, upper extremity function, bowel management, and technology to enhance function in the community. New advances covered in this section include functional electrical stimulation for enhancing mobility and upper extremity function.

Patterns of anismus and the relation to biofeedback therapy

PURPOSE

A study was undertaken to assess physiologic characteristics and clinical significance of anismus. Specifically, we sought to assess patterns of anismus and the relation of these findings to the success of therapy.

METHODS

Sixty-eight patients were found to have anismus based on history and diagnostic criteria including anismus by defecography and at least one of three additional tests: anorectal manometry, electromyography, or colonic transit time study. Interpretation of defecography was based on the consensus of at least three of four observers. Anal canal hypertonia (n = 32) was defined when mean and maximum resting pressures were at least 1 standard deviation higher than those in 63 controls. There were two distinct defecographic patterns of anismus: Type A (n = 26), a flattened anorectal angle without definitive puborectalis indentation but a closed anal canal; Type B (n = 42), a clear puborectalis indentation, narrow anorectal angle, and closed anal canal. Outcomes of 57 patients who had electromyographybased biofeedback therapy were reported as either improved or unimproved at a mean follow-up of 23.7 (range, 6-62) months. These two types of anismus were compared with biofeedback outcome to assess clinical relevance.

RESULTS

Patients with Type A anismus showed greater perineal descent at rest (mean, 5.1 vs. 3.5 cm; P < 0.01), greater dynamic descent between rest and evacuation (mean, 2.7 vs. 1.4 cm; P < 0.01), greater difference of anorectal angle between rest and evacuation (mean, 14.6 vs. -3.1 degrees; P < 0.001), higher mean resting pressure (mean, 77.1 vs. 62.8 mmHg; P < 0.05), lower mean squeeze pressure (58.8 vs. 80.7 mmHg; P < 0.05), and a higher incidence of anal canal hypertonia (69.2 vs. 33.3 percent; P < 0.01) than did patients with Type B anismus. Only 25 percent of patients who had Type A anismus with anal canal hypertonia were improved by biofeedback therapy. Conversely, 86 percent of patients with Type B anismus without anal canal hypertonia were successfully treated with biofeedback (P < 0.001; Fisher's exact test).

CONCLUSIONS

These two distinct physiologic patterns of anismus correlate with the success of biofeedback treatment. Therefore, knowledge of these patterns may help direct therapy.

Surgery for constipation: a review

PURPOSE

Constipation is related to intestinal motility disorders (colonic inertia (CI)), pelvic floor disturbances (pelvic outlet obstruction), or a combination of both problems. This review summarizes the physiologic and pathophysiologic changes in patients with intractable constipation and gives an overview of surgical treatment options.

RESULTS

Although subtotal colectomy with ileorectal anastomosis is the best surgery for CI, there are still approximately 10 percent of patients who will complain of pain and constipation. A completion proctectomy and an ileoanal pouch procedure may be a viable option in a highly select group of patients. In patients with megabowel, reported results are mixed. Subtotal colectomy, partial colectomy for megacolon, and the Duhamel procedure for megarectum have all been reported with variable results. In patients with an isolated distended sigmoid colon, sigmoid colectomy has achieved good results. Anorectal myectomy has not been proven to be successful in the long term. However, in patients with adult short segment Hirschsprung's disease, myectomy can be successful. Patients with pelvic outlet obstruction can be successfully treated with biofeedback. In a small group of patients with a rectocele or a third degree sigmoidocele, surgical intervention yields a high success rate. Division or resection of the puborectalis muscle is not recommended. In patients with a mixed pattern of CI and pelvic outlet obstruction, surgical intervention alone is often not successful. These patients achieve better results by conservative treatment of pelvic outlet obstruction, followed by a colectomy.

CONCLUSION

Surgical intervention for patients with intractable constipation is rarely necessary. However, thorough preoperative physiologic testing is mandatory for a successful outcome.

Level of highest mean resting pressure segment in the anal canal. A quantitative assessment of anal sphincter function

PURPOSE

Even with the development of new technologies, the mechanism of fecal continence is still not completely understood. This study evaluates the relative position of the highest mean resting pressure (HMRP) in the anal canal and its correlation with function in incontinent patients and in controls.

METHODS

Sixteen incontinent patients (mean age, 47.1 +/- 13.9 (range, 18-63) years; 12 female) and 16 controls (mean age, 35.4 +/- 8.7 (range, 24-58) years; 12 female) were studied using a water-perfused eight-port radial catheter computer-assisted vectromanometry. Position of the HMRP was analyzed in relation to the anal verge (D1) and to the proximal functional border of the anal canal (D2).

RESULTS

Controls had HMRP located more distally in the anal canal, because D2 was significantly higher than D1 (mean, 3.45 +/- 0.75 vs. 1.81 +/- 0.63 cm; p + 0.001). For incontinent patients, D1 and D2 were similar (mean, 1.86 +/- 0.75 vs. 2.08 +/- 1.11 cm; not significant). Comparison of the relative position of the HMRP between patients and controls showed a more proximal location for incontinent patients than controls (mean, 49.1 +/- 12.1 percent vs. 35.4 +/- 10.2 percent; p = 0.002).

CONCLUSIONS

Position of the HMRP is significantly more proximal for incontinent patients than for controls, and measurement of the distance from the anal verge to the HMRP in relation to the full length of the anal canal may represent another way to quantitatively assess anal sphincter function.

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.

Physiology of ileal pouch-anal anastomosis. Current concepts

PURPOSE

Increasing experience with ileal pouch-anal anastomosis (IPAA) associated with increasing knowledge about anorectal physiology has lead to a large number of publications. The purpose of this review is to evaluate the current understanding of fecal continence as revealed by the evolution of the ileoanal procedure.

METHODS

Review of the literature covering the most important physiologic parameters involved in fecal continence was undertaken.

RESULTS

Rectoanal inhibitory reflex is probably absent after IPAA but is preserved when distal anorectal mucosa is spared. Anal resting pressure decreases but is less affected when the internal anal sphincter is less traumatized. Squeeze pressure is not importantly affected, and the importance of reservoir function as a determinant of stool frequency is emphasized. IPAA does not affect the coordination between pouch and anal canal motility in the majority of cases. Normal continence is preserved, even during the night, by preserving a gradient of pressure between the pouch and anal canal.

CONCLUSIONS

Physiologic concepts are well established, but controversies about the continence mechanism related to IPAA remain. The IPAA procedure has allowed discrimination of details about the function of multiple structures involved in fecal continence.