Rectal Capacity Research Articles

Defecography in patients with anorectal disorders

To evaluate the results and clinical impact of defecography in patients with anorectal disorders, 100 results of defecographic examinations from 92 patients were reviewed. The defecographic results were screened for the anorectal angle, defined both at rest and during straining, perineal descent, and abnormalities of the rectal configuration during straining. Anal manometry, saline infusion test, rectal capacity measurement, and anal electromyography (EMG) were also performed. There was a significant difference (P less than 0.001) both at rest (22 degrees) and during straining (12 degrees) between the two anorectal angle measurements. Incontinent patients had a larger anorectal angle, both at rest and during straining, than continent patients (P less than 0.04), but with a large overlap. The anorectal angle was not influenced by gender or age. An abnormal rectal configuration was found in 62 defecographic examinations. From the 8 patients with rectopexy performed for a large rectocele or intussusception, incontinent patients with an intussusception had the best results. In four patients, anal EMG showed an increased activity of the external sphincter during straining. Two of these four patients had abnormal defecograhic results. No correlations were found between anorectal angle and the other function tests. In conclusion, the anorectal angle lacks clinical relevance. In patients with defecation problems, defecography may be indicated whenever other investigations (physical examination, anal manometry, anal EMG) have excluded local pathology or a spastic pelvic floor syndrome. In these situations, defecography could detect an intussusception, which could easily be treated with rectopexy.

Successful surgical treatment of idiopathic colonic dysmotility. The role of preoperative evaluation of coloanal motor function.

Identification of patients with severe idiopathic colonic dysmotility who would benefit from surgery can be difficult. Colonic transit studies and anorectal manometry were applied to 12 women with severe constipation before subtotal colectomy. Delayed transit was noted in all patients with most exhibiting left-sided colonic arrest. Mean anal resting pressure and rectal capacity were similar to that in healthy controls. Pathologic examination results revealed decreased argyrophilic neurons in the colonic myenteric plexus. At 24 months postoperatively, all patients were satisfied with their results and mean (+/- SEM) weekly bowel movement frequency was 17 +/- 3 (compared with 0.8 +/- 0.2 preoperatively). Preoperative coloanal function studies therefore aid in the selection of patients who will be successfully treated by surgery. Subtotal colectomy with ileorectal anastomosis is the preferred operation because dysmotility can originate from either side of the colon.

Soiling: anorectal function and results of treatment.

Forty-five patients with soiling but without faecal incontinence were evaluated by means of anorectal function investigations (anal manometry, rectal capacity and saline infusion test). The causes of soiling and the effect of treatment on both soiling and anorectal function were studied. The results were compared with a control group of 161 patients without soiling or incontinence. The diagnoses were haemorrhoids (10), mucosal prolapse (7), rectal prolapse (6), fistulae (5), proctitis (3), faecal impaction (2), rectocele with intussusception (2), scars after fistulectomy (2) and others (8). Simple inspection and proctoscopy were generally sufficient to establish a diagnosis. For two patients the diagnosis rectocele was made after defaecography. Anorectal test results did not differ between the soiling and control group, did not contribute to establish a diagnosis and did not change after treatment. Only patients with a rectal prolapse had abnormal results in anorectal function tests: a low basal sphincter pressure and a limited continence reserve. Appropriate therapy resulted in complete recovery (44%) or improvement of symptoms (29%).

Pelvic Floor Physiology

Pelvic floor physiology is poorly understood. The funnel shape of the pelvic floor and anal canal is uniquely developed to provide discriminatory continence of gas, liquid, and solid. Proximally, the pelvic floor consists of the pubococcygeus and iliococcygeus muscles. Distally, the anal canal is surrounded by the internal and external sphincter muscles. The anorectal ring is situated between the proximal pelvic floor and the distal anal canal. It is the site of the puborectalis muscle, which is anatomically, neurologically, and functionally merged with the deep portion of the external sphincter muscle. It is at this site that unique forces act to create both a flutter valve and the anorectal angle with the flap valve. Extrinsic pressures at this level reinforce both the flap valve and the flutter valve. Intrinsic pressures are generated by all of the surrounding muscles to produce a high-pressure zone. These factors are critical, but many other factors, such as rectal capacity, compliance, colonic transit, motility, and sensory mechanisms, also interact in a complex way to provide normal continence and defecation. Not surprisingly, no single test allows a complete assessment of the interactions of all these factors. Nevertheless, analysis of components thought to be important in pelvic floor physiology has contributed significantly to the understanding of normal as well as abnormal physiology. Although clinical evaluation continues to be the cornerstone of the diagnosis of pelvic floor disorders, anorectal physiological testing has contributed significantly to our understanding of the dynamics of the pelvic floor. With the refinement of existing techniques and the addition of new investigative tools, it is anticipated that knowledge of pelvic floor physiology will continue to grow.

Urinary Diversion to the Augmented and Valved Rectum: Preliminary Results with a Novel Surgical Procedure

A new method for urinary diversion to the rectum was elaborated in animal experiments and currently has been used in 19 patients. Reflux of the rectal content to the colon and to the upper urinary tract is prevented by the fashioning of an intussusception valve at the rectosigmoid junction. The rectum is augmented by anastomosing an ileal patch to the anterior rectal wall. A transverse colostomy protects the construction for 6 to 8 weeks. Of the 19 patients 3 had local recurrence or metastasis within 6 months. Thus, 16 patients with a followup of 3 to 14 months are evaluable. All patients are continent during the daytime with an emptying frequency of 3 to 5 times and dry at night with a frequency of 0 to 2. In 3 patients partial sliding of the sigmoid intussusception valve occurred causing reflux of rectal contents to the sigmoid and to the right ureter in 1. Reflux to the upper urinary tract has not been revealed in any of the other patients. With 1 exception excretory urography has demonstrated either improvement or stabilization of the upper urinary tract post-operatively. The rectal capacity increased from 200 to 700ml. after 6 months. With the reservoir full the mean basal pressure was 17cm. water and the mean maximum pressure was 24cm. water.

Megarectum.

Evaluation of the rectum by barium enema does not correlate well with rectometrographic studies and is not predictive of bowel function. The purpose of the present study was to describe clinical and functional data in patients with chronic idiopathic constipation, where a megarectum was diagnosed by a rectometrogram. Among 355 patients who underwent rectal elasticity studies, 35 were found to have a megarectum (maximum tolerable volume above 320 ml in women and 440 in men) for which no specific etiology was recognized. They, and a group of 11 healthy controls who were not sensitive to stress, underwent studies of stool frequency, colonic transit time of radiopaque markers, rectal elasticity, and anorectal pressures and reflexes. The elasticity coefficient of the rectal wall was decreased in patients as compared to controls (P less than 0.01). Seven patients had onset of symptoms at birth, with maximum tolerable volume in the rectum between 460 and 900 ml, and all were incontinent for feces. Studies of colonic transit times demonstrated normal function in the right and left colon, but there was rectosigmoid stagnation (transit time of 122 +/- 17 hr vs 8 +/- 2 in stress-free controls; X +/- SE; P less than 0.001). In the other 28 patients (late-onset megarectum), in contrast to the congenital group, there was a marked female preponderance, and their recorded stool frequency (4 +/- 0.7/week) was greater than the recalled frequency (1.4 +/- 0.2/week; P less than 0.001). Only half suffered from fecal incontinence. They did not have a greater rectal capacity when colonic transit times were prolonged (455 +/- 27 ml) than when normal (422 +/- 27). Rectal pressure was similar at the level of conscious sensation of filling, regardless of rectal capacity, suggesting a motor, rather than a sensory, abnormality. The amplitude of the rectoanal inhibitory reflex was decreased (P less than 0.001) as compared to controls, sometimes mimicking the findings of Hirschsprung's disease, but increasing rectal distension always induced a relaxation of the internal anal sphincter. The notion of a megarectum, which tolerates large amounts of fluid without sensation, lacks elasticity, and is accompanied by an abnormal rectoanal inhibitory reflex, provides an explanation for one of the mechanisms of constipation by outlet obstruction.

Biofeedback conditioning for fecal incontinence in anorectal malformations

Twenty children aged 6–18 years who had deficient fecal continence after primary and secondary surgery for anorectal malformations were treated by biofeedback conditioning. The original malformation was high in 17 cases and low in 3. Pretreatment manometric assessments and training were performed with a perfused open-tip catheter connected to a recording unit where the manometric tracings could be inspected digitally or from the pressure curve. A latex balloon was used to stimulate the rectum. The patients were taught to develop maximal sphincter contraction and synchronize the contraction with rectal distention. Rectal sensitivity was conditioned by gradually decreased balloon volumes. There were 4–11 training sessions. The follow-up time was 2–24 months. Sixteen of the 20 patients responded favorably to the training. Fecal continence and the ability to take part in a normal social life improved significantly in the responders. In the responders, the contractile power of the sphincter increased significantly while other manometric parameters (basal anal canal pressure, rectal sensitivity, rectal capacity, rectoanal inhibitory reflux) could not be influenced. Biofeedback is a safe, simple, and effective method in treating fecal incontinence associated with anorectal malformations.

The functional results after colectomy and ileorectal anastomosis for severe constipation (Arbuthnot Lane's disease) as related to rectal sensory function.

Rectoanal manovolumetry during graded isobaric rectal distension was carried out in 12 women with severe constipation classified as slow transit constipation (Arbuthnot Lane's disease). The resting anal sphincter pressure, the rectoanal inhibitory reflex and the rectal capacity were all normal. While the distension volumes required to elicit sensation of rectal filling and an urge to defaecate were within normal limits in all patients the distension pressures required to elicit such sensations fell outside the 95% limits of variation of control subjects in 4 patients. All patients were subsequently subjected to colectomy and ileorectal anastomosis. Patients with normal rectal sensory function had a satisfactory functional result after colectomy, whereas the four patients with blunted sensation did not improve. These findings suggest that rectoanal manovolumetry with determination of the distension pressures required to elicit rectal sensation is an important preoperative measure to be used in patients with severe constipation for selection of patients suitable for colectomy and ileorectal anastomosis.

The action of cisapride on the chronic constipation of paraplegia.

Paraplegic patients have intractable constipation associated with prolonged colonic transit time. The agent Cisapride significantly reduced the colonic transit time from 7.7 days to 5.1 days. It also improved the intraluminal tone in the rectum, resulting in a significant reduction in maximal rectal capacity from 305.8 ml to 224.3 ml. There was a reduction in residual urine volume from 51.5 ml to 27.7 ml. The increased number of stools containing transit markers showed that intraluminal mixing was increased by cisapride. Faecal water remained unchanged. A side effect was retention of urine in one subject after sudden withdrawal of the drug but this was avoided by its gradual reduction over 2 days.

Anorectal function and defecation dynamics in patients with rectal prolapse

Seven female patients with clinical rectal prolapse and nine healthy female control subjects were studied with anorectal manometry, external sphincter electromyography, and a saline continence test. Resting anal tone, maximum voluntary squeeze, and rectal functional capacity were significantly decreased in the rectal prolapse patients (p less than 0.02). During defecation attempts, external sphincter or pelvic floor electromyographic activity decreased in all of the control subjects, whereas six prolapse patients showed increased electromyographic activity and one had no change in activity (p less than 0.01). Continence to saline solution was also significantly impaired in prolapse patients (p less than 0.001). Postoperative studies in three patients who underwent repair revealed persistence of abnormal anorectal function and defecation dynamics. Patients with rectal prolapse have impaired resting and voluntary sphincter activity, decreased functional rectal capacity, and impaired continence. The failure of normal relaxation of the external sphincter or pelvic floor during defecation attempts, as demonstrated in the patients described herein, may contribute to the development of prolapse and denervation sphincter injury seen in such patients.

Experience with the straight endorectal pullthrough for the management of ulcerative colitis and familial polyposis in children and adults.

The first significant experience with the straight endorectal pullthrough for the management of ulcerative colitis was presented before the American Surgical Association in 1977 by Lester Martin. Since then the operation with or without modification has been used extensively. High stool frequencies in some series led to disenchantment with the straight anastomosis and to the development of various reservoir procedures to increase rectal capacity and thereby reduce frequency. As a result, no large series of straight pullthroughs is available for comparison with the reservoir modifications. Between September 1977 and September 1986, 72 children and adults, 61 with ulcerative colitis and 11 with familial polyposis, underwent endorectal pullthrough (ERPT) and straight ileoanal anastomosis under the overall direction of a single surgeon (AGC). Sixty patients have undergone ileostomy closure and form the basis of this study. Mean age at operation was 22.7 years (range 4-48 yr), and duration of active disease averaged 6 years. One-half of the patients underwent total abdominal colectomy with ERPT as a primary procedure. There were 11 cases of adhesive bowel obstruction following ERPT, and in six patients in the series permanent revision to a Brooke ileostomy was required. One patient died of hepatic failure in the late postoperative period. Follow-up has ranged from 3 months to 9 years. Mean stool frequency for the group as a whole at 3, 6, 12, 24, and 36 months was 11.8, 11.2, 9.6, 9.0, and 8.3 per 24 hours, respectively. Daytime continence was achieved in all patients. Occasional nocturnal soiling occurred in 11.1% of patients at 1 year. Stool frequency and continence were also analyzed by age group above and below 18 years and above and below 30 years. There were no statistically significant differences between these groups. The authors conclude from this study that ERPT with straight ileoanal anastomosis remains an appropriate alternative for children and adults with ulcerative colitis or familial polyposis and compares favorably with the more complicated ERPT involving a reservoir.

Measurement of rectal capacity in the assessment of patients for colectomy and ileorectal anastomosis in Crohn's colitis.

A group of 38 patients with Crohn's colitis underwent measurement of rectal capacity prior to colectomy and ileorectal anastomosis. Median values for constant and maximum tolerated volumes were significantly higher in patients who still possessed a satisfactorily functioning ileorectal anastomosis at a mean follow-up of 6.8 years, and measurement of these sensory parameters of rectal capacity was of prognostic value in predicting the likely outcome of ileorectal anastomosis.

Anal sphincter function and rectal reservoir after sphincter saving operations for carcinoma of the rectum.

Anal sphincter function and rectal reservoir were studied in 27 patients after low anterior resection, in 6 after Welch or Turnbull type pull-through surgery and in 3 after Bacon type pull-through surgery. Sixteen patients who had undergone right hemicolectomy served as a control group. Anal sphincter function immediately after low anterior resection was diminished, but improved during the following 6 months. Rectal capacity was much reduced immediately after surgery, but increased with time, and the neorectum could to some extent adapt to its new role as a reservoir. After pull-through operations, anal canal pressure and rectal compliance were significantly lower than after low anterior resection or right hemicolectomy. These findings may explain the increased frequency of bowel action after pull-through operations.

Ano-rectal function assessed by manometry and electromyography after endorectal pull-through for Hirschsprung's disease.

Since 1975 the endorectal pull-through operation for Hirschsprung's disease has been favoured in this department. Out of 16 patients, 12 were examined 8 months to 6 years later by ano-rectal manometry and external sphincter electromyography. The results indicate a normal postoperative rectal capacity and rectal sensibility. There was no internal sphincter relaxation in response to a rectal distention. Resting and reflex activity of the external and sphincter were normal.

Relationship of proctitis and rectal capacity in Crohn's disease.

In patients with Crohn's disease involving the rectum (n=25), there was an inverse relationship between rectal capacity and the degree of proctitis. However, in patients with Crohn's disease not involving the rectum (n=22) the rectal capacity was similar to that of normal controls (n=20). The frequency of defaecation was not related to the degree of proctitis or to the pressure of a colectomy and ileorectal anastomosis. Control subjects had a significantly lower frequency of defaecation than patients with Crohn's disease irrespective of involvement of the rectum.

Further experience with the rectosigmoid bladder.

Summary89 patients suffering from carcinoma of the bladder treated by cystectomy and construction of a rectal bladder were reviewed.The immediate postoperative mortality was 12.5 %, most deaths being due to infection.64 patients had been followed for 6 months to 3 years.The 64 patients possessed a total of 115 kidneys, and there was radiological evidence of postoperative deterioration in 23 instances. Anastomotic stricture formation was the commonest complication.Measurement of rectal bladder capacity showed the functional to be smaller than the anatomical. This was shown radiologically to be due to a change of posture; the capacity is greater when the patient is supine than when he is erect.Nearly all patients were continent by day; leakage at night occurred in 40 %29 of 32 patients were at work 1 year after operation.