gamma-Aminobutyric acid enhances the tone of human internal anal sphincter.

The effect of gamma-aminobutyric acid (GABA) on the human internal anal sphincter was investigated. Cumulative applications of GABA produced concentration-dependent contractions (10(-8)-10(-5) M) of the isolated human sphincter. Pretreatment with bicuculline (GABAA antagonist) turned them to relaxation. Muscimol, a GABAA agonist, induced concentration-dependent contractions (10(-8)-10(-5) M); however, baclofen (GABAB agonist, 10(-8)-10(-5) M) promoted concentration-dependent relaxation of the strips. These results suggested that both excitatory GABAA receptors and inhibitory GABAB receptors exist in the internal anal sphincter. Oral administration of sodium valproate (1600 mg/day), a GABA transaminase inhibitor, enhanced the anal canal resting pressure in 10 normal volunteers. Anal manometry showed a significant elevation in tonus without affecting amplitudes or frequencies. These results indicated that endogenous GABA, which was increased by sodium valproate, produced elevations in the anal canal resting pressure through its specific receptors in the human internal anal sphincter.     

Anal sphincter function after colectomy, mucosal proctectomy, and endorectal ileoanal pull-through

Anal sphincter function in patients before and after colectomy, mucosal proctectomy, and endorectal ileoanal pull-through was assessed prospectively. In 21 patients with ulcerative colitis, Gardner's syndrome, or familial polyposis, anorectal manometry was performed before and eight weeks after ileoanal pull-through. The mean +/- SEM maximal anal sphincter resting pressure decreased from 86 +/- 5 to 68 +/- 4 mm Hg after operation. The net change in pressure with squeeze, however, was greater after ileoanal pull-through than before operation (100 +/- 9 v 92 +/- 7 mm Hg). In 19 of 21 patients after operation, balloon dilation of the ileal pouch resulted in relaxation of the internal anal sphincter and contraction of the external anal sphincter. Mean +/- SEM 24-hour stool frequency decreased from 7.6 +/- 0.6 at one month to 6.2 +/- 0.5 at three months. It was concluded that ileoanal pull-through preserves continence and an acceptable stool frequency by maintaining nearly normal anal sphincter function.     

Proctocolectomy and ileoanal pouch anastomosis without conservation of a rectal muscular cuff

The technique of proctocolectomy and formation of an ileal reservoir with ileoanal anastomosis is well described. It is believed that the conservation of a rectal muscular cuff is necessary for continence but no data are available to support this contention. The aims of this study were to describe the clinical and physiological aspects of continence after proctocolectomy and ileal J pouch anastomosis without conservation of a rectal muscular cuff. Eighteen consecutive patients (mean age 37.3 years, 16 ulcerative colitis, two familial polyposis) who underwent proctocolectomy and ileoanal anastomosis on the dentate line were studied 6 months after closure of the loop ileostomy. The 18 patients and eight controls underwent: (a) anal manometry; (b) determination of maximum tolerable volume (MTV); (c) liquid continence test (infusion of NaCl at 60 ml/min for 25 min) with simultaneous measurement of ileal reservoir pressure. The volume evacuated during 5 min after the continence test was also measured. The frequency of bowel actions was (mean +/- s.e.m.) 5.3 +/- 0.4 per 24 h (nocturnal 1.14 +/- 0.26). Seventeen of 18 patients (94 per cent) had normal continence and defaecation; one patient was incontinent. A decrease in resting anal canal pressure (102.5 +/- 4 versus 47.5 +/- 6 cmH2O) was observed after ileoanal anastomosis. A rectoanal inhibitory reflex was elicited in one of the 18 patients (6 per cent). Patients were able to retain 1023 +/- 68 ml saline during the liquid continence test. The percentage evacuation of the ileal reservoir was 61 +/- 4.5 per cent. Correlations were found (P = 0.05) between daily stool frequency and the volume of saline retained during the liquid continence test. It is concluded that conservation of a rectal muscular cuff is not necessary for the achievement of good clinical results.     

Late functional adaptation after colectomy, mucosal proctectomy, and ileal pouch-anal anastomosis

Ileal pouch-anal anastomosis (IPAA) is currently an alternative to proctocolectomy and ileostomy for patients with ulcerative colitis or familial polyposis. Some studies have suggested significant anal sphincter damage after mucosal proctectomy. Our aim was to assess prospectively late sphincter function after IPAA. In 250 patients, anorectal pressures were assessed with a pneumohydraulic perfused catheter manometry system. Each patient underwent colectomy, mucosal proctectomy, ileoanal anastomosis of a 15 cm ileal J-pouch, and loop ileostomy. Eight weeks after IPAA, anal manometry was repeated, and the ileostomy was closed. Manometry was repeated at yearly intervals. A decline in resting tone of the anal sphincter occurred early after IPAA with a gradual recovery toward control. External sphincter squeeze after pressures were not affected by IPAA and steadily increased to 8 years after operation. During this time, a progressive increase in J-pouch capacity was noted, and 24-hour stool frequency declined from 7.9 +/- 0.3 stools to 6.5 +/- 0.3 stools (p less than 0.05). We conclude that mucosal proctectomy results in internal anal sphincter trauma but is associated with long-term sphincter recovery, coupled with a significant improvement in external sphincter capacity, ileal pouch volume, and stool frequency.     

Anoneorectal evaluation after colectomy and endorectal ileoanal anastomosis in children and young adults

Recent improvements in the technique of colectomy, rectal mucosectomy, and endorectal ileoanal anastomosis allow a satisfactory result in most patients. However, the clinical outcome is not entirely satisfactory in about 5% to 10% of patients because of excessive stool frequency or episodic fecal incontinence or both. We evaluated anoneorectal function postoperatively to help explain the mechanisms of the difficulties. Six patients with imperfect functional results (group 1) and 6 with good functional results (group 2) after ileoanal anastomosis and closure of the loop ileostomy were compared with 12 healthy volunteers who had not had operation, through a series of tests designed to evaluate anal sphincter and neorectal function. All patients were instructed in balloon dilation of the neorectum to develop a reservoir while awaiting closure of the ileostomy. Anal sphincter manometric measurements of resting and squeeze pressures were obtained with a 4-channel probe attached to a noncompliant pneumohydraulic perfusion system. Incremental inflation of an intraluminal bag while pressures were simultaneously recorded allowed determinations of neorectal capacity and distensibility. The efficiency of neorectal evacuation was assessed by instilling a labeled synthetic viscous load into the distal bowel. Patients in group 1 had lower resting anal pressures (P less than 0.05), lower squeeze pressures (P less than 0.05), smaller neorectal capacities (P = 0.13), and less neorectal distensibility (P = 0.27) than patients in group 2. Furthermore, the values for patients in group 2 closely approximated those found in healthy volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)     

A clinico-physiological comparison of ileal pouch-anal and straight ileoanal anastomoses

The ileal pouch-anal anastomosis improves clinical results after colectomy and mucosal proctectomy compared to the straight ileoanal anastomosis. The question was what physiologic changes brought about by the pouch led to the improvement. Among 124 patients who had had ileoanal anastomosis, 25 volunteered for a detailed clinicophysiologic evaluation. Fourteen had had the ileal pouch-anal operation a mean of 8 months previously, and 11 had the straight ileoanal operation a mean of 25 months previously. Both groups of patients had satisfactory anal sphincter resting pressures (mean +/- SEM, pouch = 68 +/- 8 cm H2O, straight = 65 +/- 9 cm H2O, p greater than 0.05) and neorectal capacities (pouch = 278 +/- 26 ml, straight = 233 +/- 36 ml, p less than 0.05), and all could evacuate spontaneously. However, the pouch patients had a more distensible neorectum (delta V/delta P pouch = 9.5 +/- 1.3 ml/cm H2O, straight = 4.9 +/- 0.9 ml/cm H2O, p less than 0.05) and smaller amplitude neorectal contractions (pouch = 36 +/- 5 cm H2O, straight = 90 +/- 13 cm H2O; p less than 0.05). We concluded that the pouch-anal anastomosis increased the distensibility of the neorectum and decreased its propulsive drive, and so improved clinical results.     

Anal sphincter electromyography after colectomy, mucosal rectectomy, and ileoanal anastomosis

Electromyography (EMG) was used to evaluate the external anal sphincter in 27 patients following colectomy, distal mucosal rectectomy, and ileoanal anastomosis. The studies were conducted four months to 58 months (mean, 20 months) following the restoration of intestinal continuity. Nine patients underwent endoanal rectal mucosal stripping, while in 18 patients the rectum was everted to facilitate the stripping. Postoperative continence varied widely, from perfect to frequent and severe mucous of fecal leak. Abnormal motor-unit potentials were identified by EMG in nine patients and this finding was usually associated with poor continence. The sex of the patient, technique of mucosal stripping, and type of anastomosis did not influence the EMG result, but patients at least 40 years old all had abnormal EMGs. We conclude that poor continence after ileoanal anastomosis correlates with an abnormal EMG of the external anal sphincter. The cause of the EMG abnormality is unclear.     

Techniques d’anastomoses iléoanales avec réservoir

Complete proctocolectomy with ileoanal pouch anastomosis is the gold standard for the treatment of familial adenomatous polyposis and ulcerative colitis. In Crohn’s disease, this technique may be considered for selected patients free of anal or small bowel lesions. The two main techniques used for ileoanal anastomosis are the manual anastomosis following mucosectomy (Parks’ procedure, the reference technique), and the stapled anastomosis, the most used procedure worldwide. A third technique exists also, consisting in rectal eversion with section on the dentate line (Hautefeuille procedure); this technique avoid conservation of the anal transitional zone in stapled ileoanal anastomosis, and the risk of incomplete mucosectomy associate with Parks’ procedure. Finally, it is possible today to perform this intervention by laparoscopic approach, provided the operating team has the required training.     

Preservation of continence after ileoanal anastomosis by the coordination of ileal pouch and anal canal motor activity.

Nocturnal incontinence may occur after ileoanal anastomosis and may be related to loss of an effective anal canal pressure barrier during sleep; how pressure and contractions in the proximal bowel influence this barrier is unknown. Our aim was to evaluate the relationship between anal canal pressure and contractions and contractile activity of the pouch in continent subjects after ileal pouch-anal anastomosis (IPAA) and of the rectum in normal controls. A fully ambulatory system for 24-hour pressure recording was used. A flexible transducer catheter was introduced endoscopically so that sensors were at 2, 3, 8, 12, 16, and 24 cm from the anal orifice in 12 healthy controls (7 men, 5 women, mean age: 35 years) and 7 fully continent IPAA patients (4 men, 3 women, mean age: 34 years) more than 12 months postoperatively. Twenty-four hour spontaneous motor activity was stored in a 2.5 megabyte (MB) digital portable recorder. Mean anal canal pressure was calculated, and rectal motor complexes and ileal pouch large pressure waves were characterized. During sleep, resting anal canal pressures were similar in the two groups (72 +/- 12 mm Hg in controls versus 66 +/- 9 mm Hg in IPAA patients [mean +/- standard deviation (SD)], p = NS), but anal canal pressure showed cyclic relaxations (periodicity: 95 +/- 11 min in controls, 54 +/- 18 min in IPAA patients, p less than 0.05), during which the mean pressure trough was 15 +/- 4 mm Hg in controls and 14 +/- 5 mm Hg in IPAA patients (p = NS). In the control patients, during sleep, a mean of six rectal motor complexes were identified (range: 3 to 9). In patients with IPAA, during sleep, a mean of eight large pressure waves per hour were identified (range: 2 to 20). Importantly, in both controls and patients, rectal motor complexes or large pressure waves were always accompanied by rapid return of anal canal pressure from trough to basal values and increased contractile activity. We concluded that, in healthy patients and in continent patients after IPAA, motor activity of the rectum and of the ileal pouch was associated with changes in pressure and contractile activity of the anal canal so that rectal- and neorectal-anal canal pressure gradient, and, in turn, fecal continence were preserved.     

Mechanisms of rectal continence. Lessons from the ileoanal procedure

To clarify mechanisms of rectal continence, we evaluated 34 patients who had straight or J-pouch ileoanal anastomosis. This evaluation included pressures, anal inhibitory reflex, neorectal capacity, neorectal compliance, and the ability to discriminate stool from gas. Both groups of patients had satisfactory anal sphincter resting pressures and neorectal capacities, and all could discriminate stool from gas despite the absence of any rectal mucosa. We conclude that normal rectal mucosa is not necessary to be able to discriminate stool from gas; a long rectal muscular cuff is not necessary for rectal sensation; essentially normal sphincter function is preserved, and this procedure does not normally fail because of inadequate sphincter function or the absence of the anal inhibitory reflex; and in the presence of normal sphincter function, continence is not dependent on the presence of normal mucosa or the anal inhibitory reflex but correlates with reservoir capacity and compliance as well as with the frequency and strength of intrinsic bowel contractions.     

Long-term pathophysiological studies on loop ileostomy and ileoanal anastomosis

Mucosal proctectomy with ileoanal anastomosis (IAA) had been performed on 37 patients with adenomatosis coli and 16 with ulcerative colitis between 1978 and 1987. These patients were followed up for a mean of 7.5 years. In 38 cases (73%), this procedure was completed by closure of loop ileostomy. The mean number of bowel movements per 24 hours was 6.0. Seven patients had occasional episodes of minor nocturnal soiling. The postoperative maximum resting anal pressure was the most important parameter reflecting clinical results and it rose from 72 to 92 cm of water during 5.3 year follow-up period after IAA. The pathophysiological studies on loop ileostomy and IAA were performed in these patients. Postoperative small bowel transit time evaluated by radioopaque markers was shortened. Daily output of water and sodium, and Na/K ratio in the ileal excreta increased and total counts of anaerobes in feces decreased. On the other hand, daily volume, Na/K ratio and PH of urine fell significantly. These phenomena were remarkable in patients who received loop ileostomy with about 60 cm defunctioning terminal ileum. These results indicate that it is necessary to maintain intestinal continuity in the ileal pouch-anal procedures.     

Anorectal manometry and ileo-anal anastomosis]

Seventeen patients (12 ulcerative colitis, 5 familial adenomatous polyposis) underwent proctocolectomy and ileal J pouch anastomosis. Anal manometry with determination of maximum tolerable volume and a liquid continence test were perform before ileo-anal anastomosis, before closure of the loop ileostomy and 12 months after closure of the loop ileostomy. All patients were continent during the daytime less 12 months after proctocolectomy. The mean stool frequency was 5 stools per day in our 17 patients. A significant increase in maximum tolerable volume and in the liquid continence test was observed during the first year after closure of the ileostomy. Anal manometry is unnecessary after ileoanal anastomosis, but preoperatively, this test is able to exclude some patients with low anal pressure.     

Anal sensation after restorative proctocolectomy for ulcerative colitis

The hypothesis that anal sensation might be better after restorative proctocolectomy with end-to-end ileoanal anastomosis than after mucosal proctectomy with endo-anal anastomosis was tested in this study. Anal sensation was measured in 14 patients before operation, 16 patients after restorative proctocolectomy with end-to-end anastomosis (RP + EEA) and 13 patients after mucosal proctectomy with endo-anal anastomosis 1 cm above the dentate line (MP + EAA). Threshold electrosensitivity was measured in the upper, mid and lower anal canal by means of a bipolar constant current stimulator probe. The 'recto'-anal inhibitory reflex was tested, and the patients' ability to discriminate between flatus and faeces and to release flatus 'safely' was assessed by interview. In the upper anal canal, threshold sensitivity was significantly greater in patients who had undergone MP + EAA than in patients who had undergone RP + EEA (P less than 0.05). In the mid and lower anal canal, electrosensitivity in the three groups of patients did not differ significantly. Twelve patients (75 per cent) regained the 'recto'-anal reflex after RP + EEA, but after MP + EAA only three patients (23 per cent) did so (P less than 0.02). Thirteen patients after RP + EEA could release flatus safely without fear of faecal leakage, compared with only four after MP + EAA (P less than 0.02). The proportions of patients in these two groups who said they were able to discriminate flatus from faeces did not differ significantly. Anal sensation and discriminatory function are significantly better after end-to-end ileoanal anastomosis than after mucosal proctectomy with endo-anal anastomosis.     

Anal sphincter function and sphincter preserving surgery

This article reviews the methods of assessing anal sphincter function and the place of sphincter-saving surgery in patients seen in the Gatrointestinal Unit of the Birmingham General Hospital between 1976 and 1984. (The main parameters for assessing sphincter function are maximinal and pressure at rest, maximum squeeze pressure, length of the high pressure zone, electromyography and parameters of rectal sensation.) Poor functional results were observed for patients having restorative surgery for rectal cancer when there is evidence of extrarectal tumour infiltration. It has now become our policy to avoid primary resection and anastomosis for fixed rectal cancer and for cancer involving the side walls of the pelvis. We would also question the value of low sphincter-saving surgery in patients with manometric evidence of a weak anal sphincter. Assessment of rectal capacity has been of predictive value in selecting patients suitable for ileorectal anastomosis in Crohn's disease. Sphincter preserving surgery in ulcerative colitis by ileorectal anastomosis or ileoanal anastomosis with pouch is unpredictable and continence is often imperfect. Repair of a rectal prolapse alone by a posterior rectopexy restores continence to 70% of patients but if incontinence persists post anal repair is beneficial in approximately 50% of cases. Incontinence which does not improve with medical therapy can often be restored by surgical treatment. Post anal repair restores continence to approximately 70% of cases and sphincter reconstruction to 80%.     

Successful endoscopic needle knife therapy combined with topical doxycycline injection of chronic sinus at ileal pouch–anal anastomosis

Aim Chronic presacral sinus at the anastomosis after restorative proctocolectomy and ileal pouch–anal anastomosis (IPAA) has been difficult to manage and results in a high rate of pouch failure. The aim was to present a novel technique with a combining endoscopic doxycycline injection and needle knife therapy for a sinus at the ileoanal anastomosis. Methods We applied repeat Doppler ultrasound‐guided endoscopic needle knife therapy to open the orifice of the anastomotic sinus followed by topical injection of doxycycline. Results After six sessions of the endoscopic therapy, the refractory sinus was completely healed. Conclusion The Doppler ultrasound guided endoscopy therapy may provide an alternative treatment option for the patients with anastomotic sinus.     

Topical phenylephrine increases anal sphincter resting pressure

BACKGROUND: Phenylephrine is an alpha1-adrenergic agonist which causes contraction of human internal anal sphincter muscle in vitro. Its intra-arterial administration in animals has been shown to increase resting sphincter pressure in vivo. In this study the effect of topical application of phenylephrine on resting anal pressure in healthy human volunteers was investigated. METHODS: Twelve healthy volunteers had measurements of maximum resting sphincter pressure (MRP) and anodermal blood flow taken before and after topical application of increasing concentrations of phenylephrine gel to the anus. To determine the duration of effect of the agent, readings were taken throughout the day after a single application. RESULTS: There was a dose-dependent rise in the resting anal sphincter pressure, with a small 8 per cent rise after 5 per cent phenylephrine (P = 0.012) and a larger 33 per cent rise with 10 per cent phenylephrine (mean(s.d.) MRP 85(12) cmH2O before versus 127(12) cmH2O after treatment, P < 0.0001). Thereafter no additional response was noted with higher concentrations of phenylephrine. The median duration of action of a single application of 10 per cent phenylephrine was 7 (range from 6 to more than 8) h. CONCLUSION: Topical application of 10 per cent phenylephrine gel to the anus produces a significant rise in the resting anal sphincter pressure in healthy human volunteers. This represents a potential novel therapeutic approach to the treatment of passive faecal incontinence associated with a low resting anal sphincter pressure.     

Adenocarcinoma Arising Below an Ileoanal Anastomosis After Restorative Proctocolectomy for Ulcerative Colitis: Report of a Case

We report a case of adenocarcinoma developing in remnant rectal mucosa below a hand-sewn ileal pouch–anal anastomosis (IPAA) after restorative proctocolectomy for ulcerative colitis (UC). To our knowledge, this is the first such case to be reported from Japan. A 60-year-old man with a 13-year history of UC underwent proctocolectomy with a hand-sewn IPAA and mucosectomy for anal stenosis and serious tenesmic symptoms. About 7 years later, a follow-up endoscopy showed a flat elevated malignant lesion, 2 cm in diameter, below the ileoanal anastomosis. He was treated by abdominoperineal resection of the pouch and anus with total mesorectal excision. Histopathological examination of the resected specimen confirmed the presence of a well-differentiated adenocarcinoma but there were no metastatic lymph nodes. He recovered uneventfully and remains well without evidence of recurrent disease 2 years and 3 months after his last operation.     

Absorption of bile acids after ileoanal anastomosis

Absorption of bile acids was investigated using 75Se-homotaurocholate (SeHCAT) in 27 patients with ileoanal anastomosis and J-pouch, 7 patients with conventional ileostomy and 9 non-operated patients with ulcerative colitis. Retention of SeHCAT at seven days was higher in non-operated patients than in patients with ileoanal anastomosis (P less than 0.001) or conventional ileostomy (P less 0.01). There was no difference in retention of SeHCAT between patients with ileoanal anastomosis or conventional ileostomy. Malabsorption of bile acids was not associated with changes in blood chemistry or faecal fat excretion. Patients with ileoanal anastomosis and low retention of SeHCAT had more severe villous atrophy of the pouch mucosa than those with high retention (P less than 0.05). In conclusion, both patients with ileoanal anastomosis and conventional ileostomy have impaired absorption of bile acids when compared with non-operated patients with ulcerative colitis. In patients with ileoanal anastomosis, impairment of bile acid absorption is related to villous atrophy of the pouch mucosa.     

Possible role of the autonomic nervous system in sphincter impairment after restorative proctocolectomy

Peroperative manometry was performed in 12 patients operated on with endoanal proctectomy and a hand-sewn pouch-anal anastomosis and in 12 in whom proctectomy was performed entirely from above, with the ileal pouch stapled to the top of the anal canal. Results from both groups showed that division of the superior rectal artery reduced the median (95 per cent confidence interval (c.i.)) resting anal pressure from 77.5 (69.9-83.3) mmHg to 64.5 (55.2-70.0) mmHg (P < 0.01). Complete rectal mobilization to the pelvic floor decreased resting pressure by an additional 22 per cent, to a median of 50.0 (95 per cent c.i. 40.1-53.5) mmHg (P < 0.01). After completion of anastomosis, irrespective of the operative technique used, a further decline in median pressure to 35.0 (95 per cent c.i. 26.0-47.7) mmHg could be demonstrated (P < 0.05). This study indicates that anal sphincter pressure is reduced to a similar extent after hand-sewn and stapled anastomoses. Injury to the autonomic nervous supply to the anal sphincter mechanism might be the major cause for this reduction.     

Langzeitergebnisse der Kontinenzfunktion nach ileoanaler Pouch-Anlage

An important aim of proctocolectomy with ileal pouch-anal anastomosis (IPAA) is to maintain anal continence. Anal sphincter disruption during IPAA is felt to play an important role in loss of continence, which is described in up to 30% of the treated patients in the early postoperative period. Although sphincter function recovers gradually after surgery, some patients stay incontinent. In our investigation of possible parameters involved in preservation of continence after this operative procedure, we focused on changes in anal manometry. We compared these findings with the functional results obtained by questioning the patients and physical examination. Anal manometry was performed with a low-compliance hydraulic perfusion system. All patients underwent a J-pouch procedure with a short rectal cuff for ileoanal reconstruction. We examined 25 patients, 13 underwent operation for the treatment of ulcerative colitis, 12 because of adenomatous polyposis. In the colitis and polyposis group, 28% of the patients reported events of soiling. Three patients (12%) were incontinent. The remaining 15 patients were completely continent. The median time after operation was 58 months, ranging from 12 to 96 months. Comparing the results of anal manometry with standard values of ten age- and gender-matched healthy volunteers, it was found that there was a significant increase in the threshold of balloon awareness and urge to defecate. These sensations were sometimes elicited by pouch contractions. Median pouch- compliance was also clearly elevated in comparison to rectal compliance (P<0.005). Inhibitory reflexes during balloon inflation could not be evoked in any of the patients. Comparing continent with incontinent patients there were significant differences in balloon awareness, urge to defecate, and stool frequency (P<0.01,P<0.01 andP<0.001, respectively). But in contrast to other publications, we could not find significant differences in anal sphincter length, resting and squeezing, anal canal pressure. Pouch compliance was lowered in incontinent patients and negatively correlated with stool frequency (P<0.001,r=?0.82). In conclusion, our study indicates that anal sphincter resting pressure alone is not a crucial factor in continence preservation in the long-term after total proctocolectomy and IPAA. Poor pouch- compliance and concomitant higher stool frequencies seem to be related to incontinence in this patient group.