Investigations of the anal sphincter before and after restorative proctocolectomy

Postoperative changes of manometry after restorative proctocolectomy in Korean ulcerative colitis patients

AIM

To investigate the changes of postoperative anal sphincter function and bowel frequency in Korean patients with ulcerative colitis (UC).

METHODS

A total of 127 patients with UC who underwent restorative proctocolectomy (RPC) during 20 years were retrospectively analyzed. The parameters of anal manometry and bowel frequency were compared according to the 6-mo intervals until 24 mo postoperatively. Manometry was used to measure the maximal squeezing pressure (MSP) and maximal resting pressure (MRP).

RESULTS

MSP decreased after surgery until 6 mo (157 to 142 mmHg); thereafter, it improved and was recovered to and maintained at the preoperative value at 12 mo postoperatively (142-170 mmHg, P < 0.001). Although the decreased MRP (65 to 56 mmHg) improved after 18 mo (62 mmHg), it did not completely recover to the preoperative value. The decreased rectal capacity after surgery (90 to 82 mL) gradually increased up to 150 mL at 24 mo. Although bowel frequency showed significant gradual decreases at each interval, it was stabilized after 12 mo postoperatively (6.5 times/d).

CONCLUSION

Postoperative changes of manometry and bowel frequency after restorative proctocolectomy in Korean patients with UC were not different from those in Western patients with UC.

The physiology of ileo-anal pouch function

Even excellent clinical function after ileo-anal pouch construction is associated with a variety of physiological abnormalities. Small bowel intestinal motility is essentially normal but the ileal reservoir serves to markedly suppress the ileal motor response both to progressive distension by intestinal contents and to transmitted myoelectrical complexes. As a result, the healthy pouch can accommodate a large volume of intestinal content before the rising baseline pressure and the appearance of large isolated contraction waves produce an urge to defecate. Evacuation in the normal pouch patient is rapid and highly efficient and is achieved by means of the Valsalva maneuver without any evidence of significant intestinal propulsion. External anal sphincter function is fully preserved but internal anal sphincter function is significantly impaired in the immediate postoperative period. Recovery occurs over the next 6 to 12 months but is often incomplete. Bacterial overgrowth in the pouch and prepouch ileum is almost universal and results in the premature deconjugation of primary bile salts and accumulation of secondary bile salts within the pouch. These produce morphologic changes in the ileal mucosa, and their excretion in pouch effluent gradually depletes the bile salt pool. Anerobic organisms also bind with vitamin B12 and the vitamin B12-intrinsic factor complex, resulting in subtle but measurable reductions in vitamin B12 levels in pouch patients. Finally, anerobic fermentation of mucus and undigested carbohydrate results in excessive quantities of short chain fatty acids within the pouch lumen. The clinical significance of these substances is unclear, but they may have an adverse action on both ileal mucosal and smooth muscle function. In essence, however, the pouch surgeon can maximize the likelihood of good clinical function by constructing a large capacity pouch, by avoiding surgery in patients with clearly deficient anal sphincter mechanisms, and by careful attention to pouch-anal anastomotic technique.

Anal transitional zone and columnar cuff in restorative proctocolectomy

The popularity of double stapling the ileal pouch-anal anastomosis probably owes more to the technical ease it brings than to histological considerations or functional results. It is preservation of a 'columnar cuff' of mucosa, rather than the restricted site of the anal transitional zone, that should be the focus of research with respect to long-term risk of malignancy and inflammatory complications. If cancer is present in colon that has been removed for ulcerative colitis, there is a 25 per cent incidence of dysplasia in the columnar cuff in the short term. In other circumstances, those who are spared from carcinoma by colectomy are likely to have a similar risk of developing dysplastic change in the columnar cuff with longer follow-up. Double stapling the pouch-anal anastomosis and preserving the anal canal mucosa improves function, but long-term surveillance of the columnar cuff is then required, including biopsies.

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.

Pudendal neuropathy in evacuatory disorders

PURPOSE

Aims of the present study were to assess frequency of pudendal neuropathy in patients with constipation and fecal incontinence, to determine its correlation with clinical variables, anal electromyographic assessment, and anal manometric pressures, and to determine usefulness of the pudendal nerve terminal motor latency assessment in evaluation of these evacuatory disorders.

METHODS

From 1988 to 1993, 395 patients (constipated, 172; incontinent, 223) underwent pudendal nerve terminal motor latency, electromyography, and anal manometry. Pudendal neuropathy was defined as a pudendal nerve terminal motor latency greater than 2.2 ms.

RESULTS

Patients were a mean age of 60.7 (range, 17-88) years. Overall incidence of pudendal neuropathy was 31.4 percent (constipated, 23.8 percent; incontinent, 37.2 percent; P < 0.05). Incidence of pudendal neuropathy dramatically increased after 70 years of age in both groups (22 percent vs. 44 percent; P < 0.05). Moreover, subjects with pudendal neuropathy were older than those without pudendal neuropathy (mean age, 67 vs. 57 years; P < 0.05). The presence of pudendal neuropathy was associated with decreased motor unit potentials recruitment in patients with incontinence (P < 0.01). Patients with and without pudendal neuropathy had a similar mean squeezing pressure in both groups.

CONCLUSION

Pudendal neuropathy is an age-related phenomenon. Although pudendal neuropathy is associated with abnormal anal electromyographic findings in patients with incontinence, no association with anal manometric pressures was found. Pudendal nerve terminal motor latency assessment is a useful tool in the evaluation of patients with fecal incontinence, but its role in the assessment of constipated patients remains unknown.

Update on the surgical management of ulcerative colitis and ulcerative proctitis: current controversies and problems

: The surgical management of ulcerative colitis has been revolutionized in recent years by the development of the ileal pouch-anal procedure. Although it is now the operation of choice for most patients, there remain several controversies. A variety of designs of ileal pouch are available each with advantages and disadvantages. The technique used to anastomose the pouch to the anal canal is also open to debate with some surgeons favoring distal mucosectomy with eradication of all disease and others choosing to perform a stapled anastomosis to achieve better functional results. The main concern for gastroenterologists, however, is the risk of development of pouchitis. The etiology, diagnosis, and treatment of this condition will also be discussed in this review as well as the more classical options for the surgical treatment of ulcerative colitis.

Prospectively evaluating anal sphincter function after ileal pouch-anal canal anastomosis

The decreased anal sphincter pressure that occurs after ileal pouch-anal canal anastomosis (IPAA) has usually been attributed to damage of the internal and sphincter. We hypothesized that the operation damages both the internal and the external anal sphincter. Resting pressure in the anal canal (a function of internal and external sphincters), anal squeeze pressure (a function of external sphincter only), and the rectal-anal inhibitory reflex (involving the internal sphincter) were measured manometrically in 10 patients with ulcerative colitis (4 women and 6 men; mean age, 33 years; range: 20 to 49 years). The patients were studied while awake before IPAA, under general anesthesia with striated muscle blockade just before incision, awake 2 months later before ileostomy takedown, and again under anesthesia with blockade just before takedown. The operation decreased maximum resting anal pressure while awake and during anesthesia with blockade. The decrease was detected in the proximal anal canal but not in the distal anal canal. In addition, the operation impaired anal squeeze pressure and abolished the rectal-anal inhibitory reflex. We conclude that IPAA damages both the internal and the external anal sphincter.

Double-stapled vs. handsewn ileal pouch-anal anastomosis in patients with chronic ulcerative colitis

Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the treatment of choice for most patients with chronic ulcerative colitis. Whether or not a double-stapled technique, which should preserve the anal transition zone and avoid prolonged and dilation, facilitates superior fecal continence compared with conventional mucosal resection and handsewn anastomosis is unknown.

PURPOSE

The aim of this study was to compare functional results after double-stapled and handsewn IPAA.

METHODS

Twenty-seven consecutive patients (13 females, 14 males; mean age, 37 years) who had proctocolectomy and double-stapled IPAA (J) for chronic ulcerative colitis were identified. Each was matched by sex, age, and surgeon to a control who had undergone a conventional handsewn anastomosis. Functional results at six months after ileostomy closure were compared.

RESULTS

Median stool frequency in each group was seven. The prevalence of pouchitis was 22 percent in both groups. One pouch failure occurred in each group. The percentage of patients from the double-stapled group with daytime spotting was similar to that of the handsewn group (18 percent vs. 26 percent, P > 0.5). Nighttime soiling rates were similar as well (41 percent vs. 48 percent, P > 0.5).

CONCLUSIONS

Double-stapled IPAA appears to convey no early functional advantage over handsewn IPAA for chronic ulcerative colitis.

Does the level of stapled ileoanal anastomosis influence physiologic and functional outcome?

PURPOSE

The aim of this investigation was to ascertain how the length of anal canal preserved above the dentate line in stapled end-to-end ileoanal anastomosis influenced late outcome.

METHODS

Two groups, high cuff group and low cuff group of nine subjects with stapled anastomosis, matched for sex, age, pouch configuration, and mean follow-up, representing the highest (median, 2.5 cm) and lowest (median, 0.7 cm) anal cuff lengths in our series, were selected. Physiologic and functional parameters were appraised preoperatively, at the time of ileostomy closure, and at 1, 3, 6, and 12 months after reestablishment of intestinal continuity.

RESULTS

At one year, the drop in mean anal canal resting pressure was 13 percent in the high cuff group (not significant) and 31 percent in the low cuff group (P < 0.05); mean maximum squeezing pressure did not differ significantly from preoperative values in both groups. The mean volume of the ileal pouch was higher in the low cuff group at all insufflation pressures. The rectoanal inhibition reflex reappeared in four high cuff group patients and in none of the low cuff group patients. Mean distention pressure (cm H2O) and volume (ml) eliciting urge sensation were 80 and 360 in the low cuff group compared with 40 and 240 in the high cuff group (P < or = 0.05). Daytime bowel movements and night incontinence were significantly better in the low cuff group. No statistical differences were observed for night stool frequency, daytime incontinence, pad use (day and night), discrimination between gas and feces, ability to defer evacuation, and difficulty in emptying the pouch.

CONCLUSION

Patients with stapled anastomoses and a low rectal cuff length, despite presenting lower anal resting pressure and absence of rectoanal inhibition reflex, had a better functional outcome in terms of continence than those with a high cuff length.

Anorectal function after restorative proctocolectomy and low anterior resection with coloanal anastomosis

Anorectal manometry and electromyography were studied in 17 patients before and after restorative proctocolectomy with stapled pouch-anal anastomosis, in ten patients before and after low anterior resection with stapled coloanal anastomosis, and in 35 normal controls. More than 80 per cent of patients in both groups developed abnormal oscillation of anal pressure after operation (amplitude 15-60 (median 25) cmH2O, frequency 4-10 (median 8) per min) and showed no anal relaxation in response to intermittent neorectal distension. All patients lost discriminative rectal sensation and none could perceive a normal desire to defaecate. Patients with postoperative soiling had a greater amplitude of anal pressure oscillation and lower minimum basal pressure, although those who underwent coloanal anastomosis had a greater risk of incontinence because of large asynchronous oscillations in neorectal pressure. The common pathophysiological features after restorative proctocolectomy and coloanal anastomosis probably relate to damage to the autonomic and enteric nerve supplies. The presence of an unstable internal anal sphincter may be an important cause of postoperative nocturnal incontinence.

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.

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.

The results of pouch surgery after ileo-anal anastomosis for inflammatory bowel disease: the manometric assessment of pouch continence and its reservoir function

Anal sphincter function after restorative proctocolectomy has mainly been investigated by anal manometry. A significant decrease of basal pressure up to 45%, has been recorded postoperatively, possibly due to sphincter stretch during endoanal mucosectomy. Both abdominal mucosectomy and anastomosis at the level of the anorectal ring have been reported to prevent anal sphincter damage and lead to better continence. The striated sphincter is not significantly affected by the surgical procedure. Pouch-anal inhibitory reflex is partly maintained in the presence of a rectal cuff which leaves the ganglionic plexus unaltered; a satisfactory continence is also retained in the absence of the reflex when the rectum is totally excised. Pouch capacity, compliance and motility have been investigated by endoluminal balloon and probes. Pouch emptying has been studied by a "porridge" test, by a semi-solid medium labelled with technetium-99, and by other methods. A more effective storage function is achieved by large capacity reservoirs which lower the bowel frequency. The motor response to pouch distension, to a meal, and to pharmacological stimuli is usually counteracted by sphincter contraction. Ileal hypermotility may lead to fecal leakage mainly in the presence of weak sphincters. Poor pouch emptying may be related to an anal stricture.

Neurophysiologic assessment of the anal sphincters

One hundred twenty consecutive patients with either fecal incontinence (60 patients), chronic constipation (41 patients), or idiopathic intractable pelvic pain (19 patients) were prospectively assessed. Patients underwent concentric needle electromyography (EMG), bilateral pudendal nerve terminal motor latency evaluation, anorectal manometry, and cinedefecography. The most common EMG finding in patients with fecal incontinence was decreased recruitment of motor units with squeezing and polyphasic motor unit potentials; these are consistent with an injury pattern. The most common EMG finding in the constipated patients was paradoxical puborectalis contraction. This latter abnormality was also a frequent finding in patients with rectal pain, as was prolongation of pudendal nerve latency. Paradoxical puborectalis contraction was diagnosed more frequently with EMG than with cinedefecography. Inter-examination correlation was best in the incontinent group between EMG and manometry. Cinedefecography had poor correlation with EMG in all patient groups but was valuable in the detection of additional pathology such as rectoanal intussusception and anterior rectocele. Electromyography including pudendal nerve terminal motor latency assessment is a valuable adjunct in the evaluation of disorders of evacuation. The information it yields is complementary to that offered by more routine physiologic examinations.

Prospective randomized trial comparing anal function after hand sewn ileoanal anastomosis with mucosectomy versus stapled ileoanal anastomosis without mucosectomy in restorative proctocolectomy

A prospective randomized trial was performed to compare complications and function after hand sewn ileoanal anastomosis with mucosectomy (group A) with stapled ileoanal anastomosis without mucosectomy (group B) during restorative proctocolectomy. Thirty-two age- and sex-matched consecutive patients under the care of one surgeon were randomized. The median duration of anal dilatation while making the anastomosis was 19 min (range 14-33 min) and 1 min (range 0-39 min) in groups A and B respectively (P less than 0.005). The median level of the anastomosis was at the dentate line (range 0-0.5 cm) in group A and 2 cm above the dentate line (range 0.2-4.0 cm) in group B (P less than 0.005). Seven patients in group A and 11 in group B had at least one postoperative complication (n.s.). One patient in group A and four in group B developed an anastomotic stricture requiring dilatation (n.s.). One patient in group B had the reservoir removed. Function was assessed at a median of 11 months (range 7-15 months) after ileostomy closure in 14 patients in group A, and at a median of 12 months (range 5-17 months) in 14 patients in group B. Median frequency of defaecation per 24 h was 4 in both groups (group A, range 2-7; group B, range 2-10). Night evacuation (greater than once per week) occurred in seven patients in each group. All patients in both groups could delay the desire to defaecate by more than 30 min. Eleven patients in group A and 12 in group B had normal continence. Evidence to date favours a full mucosectomy. Function is not vitiated by this technique and surgical removal of the disease is more complete.

Manometric and functional comparison of ileal pouch anal anastomosis with and without anal manipulation

We report the results of postoperative physiologic and functional evaluation of 153 patients with ileal pouch anal-anastomosis (IPAA). Ninety-nine patients had anal manipulation for either mucosal proctectomy, transanal placement pursestring suture with stapled IPAA, or handsewn IPAA (manipulation). Fifty-four patients had stapled IPAA with anal pursestrings placed transabdominally without mucosectomy (no manipulation). Patients with transabdominal anal pursestring placement and stapled IPAA without mucosectomy had a higher mean maximum anal resting pressure than patients who had endoanal manipulation. This correlates with improved continence and a reduced need to wear a pad. Avoidance of anal manipulation preserves anal canal resting tone and improves the functional result after IPAA.

The stapled ileal pouch--anal anastomosis. A randomized study comparing two different pouch designs

Thirty patients were operated on with restorative proctocolectomy with an end-to-end ileal pouch-anal anastomosis constructed by double stapling (STP). Pouches were randomized to either J type or K type (folded by the principles used for the Kock continent ileostomy). Manovolumetric and functional results were compared. Patients were followed up for at least 6 months. K pouches acquired a significantly larger volume than the J-configurated pouches, and at 6 months the mean +/- SD volumes amounted to 361 +/- 59.8 ml versus 283 +/- 43.0 ml (p less than 0.01) with a concomitant reduction in 24-h frequency (4.4 +/- 1.5 versus 5.8 +/- 1.9; p less than 0.05). The initial postoperative mean reduction of resting anal pressure amounted to 33%. which was similar to that observed in a group of matched historical controls operated on with endoanal mucosectomy and hand-sutured pouch-anal anastomosis. Compared with these controls STP patients showed a superior overall functional result, most marked in the early postoperative period.

Anal manometry with microtransducer technique before and after restorative proctocolectomy. Sphincter function and clinical correlations

Anal manometry, with microtransducer technique, was performed in 55 patients after restorative proctocolectomy. Forty-two patients were followed regularly from before surgery until 12 months after surgery, and 23 patients until 24 months of function. Postoperatively, sphincter function was severely impaired. At 12 months, the mean height was less than 60 percent, mean area less than 50 percent, and mean length less than 90 percent of the preoperative values of the high pressure zone. There was no improvement between 12 and 24 months. Mean maximal squeeze pressure was restored at 12 months. Rectoanal inhibitory reflex was constantly present preoperatively, but in only 4 of 30 patients, postoperatively. Those patients with preoperative resting pressure 100 cm H2O or greater had significantly higher resting tones at 12 months than those with less than 100 cm H2O. Patients with 5 or fewer bowel movements every 24 hours had significantly higher resting tones than those with more than 6 movements every 24 hours (66 vs. 45 cm H2O). Patients with deferral 60 minutes or greater had significantly higher resting pressures than those with deferral less than 30 minutes (65 vs. 44 cm H2O). No correlation was found between resting pressure and state of continence.

Internal anal sphincter function after total abdominal colectomy and stapled ileal pouch-anal anastomosis without mucosal proctectomy

A comparison, based on results from anal manometry and continence, was made between eight patients after circular stapled ileal J-pouch-anal anastomosis without mucosectomy (Js) and seven patients after endoanal mucosal proctectomy and hand-sewn ileal pouch-anal anastomosis (Jm). The mean and range from ileostomy closure were 3.5 months (1.5 to 12) and 21.7 months (13 to 32), respectively. The mean maximum resting pressure (MRP) ( +/- SEM and range) was 81.3 mm Hg ( +/- 6.0 and 61 to 112.5) and 50.0 mm Hg ( +/- 6.2 and 17 to 62.5), respectively, for the Js and Jm groups (P less than .003). None of the Js patients experienced leakage or wore a pad, while in the Jm group 14 percent experienced minor leakage during the day and 28 percent at night. Seventy-one percent of the Jm group wore a pad at some point. Anal sphincter resting pressures and continence were better in the Js group. The improvement in MRP resulted from avoidance of injury to the internal and sphincter during dilatation and mucosectomy and the maintenance of a normal anal canal that allowed for proper closure.

Manovolumetric characteristics and functional results in three different pelvic pouch designs

Different pouch designs and techniques for the perineal approach have been on trial in an attempt to improve results after restorative proctocolectomy. The 1-year results of two currently advocated procedures, the J-pouch and the S-pouch, were compared with the results obtained in patients with a pelvic pouch fashioned according to the folding technique used for the Kock continent ileostomy, all pouches having been constructed from equal 30 cm lengths of ileum. The maximal volume of the S- and Kock pouches at one year was 420 ml (250-570) (median and (range] and 410 ml (244-490) respectively, while it was significantly less, 305 ml (200-445) in the J-pouch (p less than 0.05). The compliance of the J-pouches was also significantly lower at all distension pressures. The median day-time defaecation frequency was four and was equal in the three groups. Although there was a tendency towards a more favourable overall functional result with less soiling, and less need for night evacuations among patients with a Kock-folded pouch compared to the other pouch types these differences failed to reach statistical significance. The favourable properties of the Kock pouch, well-known also from the conteinent ileostomy and urostomy, suggest that its design should be considered an interesting alternative even for restorative proctocolectomy. These encouraging results have yet to be confirmed in a comparative randomized trial.

Anal sphincter function after colectomy, mucosal proctectomy, and ileoanal anastomosis

Anal sphincter investigations were performed in 41 patients with straight ileoanal anastomosis and in 10 controls. In 20 patients (group I) the mucosal stripping had been performed from the abdominal side, leaving 1-2 cm of distal anal mucosa. In 21 patients (group II) the anal mucosa had been stripped from the perineal side as far as the dentate line. Continence was perfect in all patients in group I and poor in 6 of 17 patients in group II, when examined 12 months after the operation. Anal canal resting pressure was normal in group I. In group II the resting pressure was significantly decreased and correlated to continence function. The maximum anal canal squeeze pressure was the same in the two groups. The slope of the regression line between pressure rise and integrated electromyography proved to be a useful criterion of the external anal sphincter function and was significantly correlated to degree of incontinence. This variable was significantly smaller in group II patients than in group I and controls. Thus, function of the anal sphincters was normal after mucosal proctectomy performed from above with preservation of a mucosal brim. Dysfunction of the internal and external anal sphincter was found after perineal mucosal dissection and was correlated to continence function.

The external anal sphincter. Relationship between anal manometry and anal electromyography and its clinical relevance

Anal manometry and anal electromyography (EMG) were performed in 45 patients to evaluate the external anal sphincter. Their symptoms were soiling (N = 6), incontinence (N = 10), and obstipation (N = 19). Clinical diagnoses were previous anal surgery (N = 16), rectal prolapse--partial, total, intussusception (N = 16), puborectalis syndrome (N = 4), neurologic disorders (N = 3), and others (N = 6). The relationship between the maximum squeeze pressure (MSP) measured with anal manometry and the maximum (voluntary) contraction pattern (MCP) and signs of denervation (DEN) measured with anal EMG were examined. The correlation coefficient between MSP and MCP was 0.55 (P less than .001) and between MSP and DEN 0.13 (NS). A normal MSP always showed a normal MCP, a normal MCP showed an abnormal MSP in 43 percent only. In conclusion, the clinical value of anal EMG seems limited. Assessment of an additional anal EMG seems indicated in incontinent patients with previous anal surgery with a low MSP to estimate muscle function, whenever anal surgery is considered. Anal EMG during straining can easily confirm the clinical diagnosis of puborectalis syndrome.

Physiological parameters influencing function in restorative proctocolectomy and ileo-pouch-anal anastomosis

Ileo-pouch-anal function has been assessed in 30 patients after restorative proctocolectomy and compared with age- and sex-matched controls. Median resting anal canal pressure was only 42 cmH2O (7-113 cmH2O) compared with 100 cmH2O (46-114 cmH2O) in controls (P less than 0.005). Maximum squeeze anal pressures were also significantly lower in pouch patients: 87 cmH2O (25-180 cmH2O) than controls: 143 cmH2O (114-171 cmH2O) (P less than 0.01). The recto-anal inhibitory reflex was absent in all pouch patients but was present in all controls. Maximum pouch or ileal pressures exceeded resting anal canal pressures in three patients. Median volume at first leak during saline infusion was 320 ml (60 ml-no leak) in pouch patients whereas the majority of controls had no leakage (median, none; 450 ml-no leak; P less than 0.05). Threshold pouch sensation (median, 50 ml (0-250 ml] did not differ from rectal sensation in controls (50 ml (0-180 ml] but pouches were less compliant than a normal rectum, median 6.8 ml/cmH2O (2.1-17 ml/cmH2O) and 11.6 ml/cmH2O (4.7-16.2 ml/cmH2O) respectively (P less than 0.05). In patients who had an episode of pelvic sepsis (n = 8) the average number of abnormal physiological indices per patient was 3.8, compared with 1.3 in those with no sepsis (P less than 0.05). There was no difference in the number of abnormalities per patient with a J pouch (2.0; n = 19) or a W pouch (1.9; n = 11).