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.     

Bone assessment in patients with ileal pouch-anal anastomosis for inflammatory bowel disease

BACKGROUND: Patients with ulcerative colitis are at risk of low bone mineral density (BMD). Proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis diminishes the risk of bone disease. The aims of this study were to assess the mechanism of low BMD and to measure bone density changes after IPAA. METHODS: Twenty patients with IPAA for ulcerative colitis, of mean(s.d.) age 38(9) (range 21-58) years, had measurements of lumbar spine and femoral neck BMD by dual energy X-ray absorptiometry, a mean(s.d.) 28(23) (range 3-84) months after proctocolectomy. Serum levels of calcium, phosphate, parathyroid hormone, osteocalcin and 25-hydroxy vitamin D were determined. Fifteen patients were followed for 28(12) (range 8-50) months. RESULTS: At baseline, six patients had spine BMD more than two standard deviations below the normal value, and three had vertebral crush fractures. Mean vitamin D values were normal and no patient had osteomalacia. BMD increased with time elapsed since IPAA (spine: r = 0.71, P = 0.005). During follow-up, mean(s.d.) changes in bone density were +2.3(3.8) and +2.1(5.6) per cent per year at the spine and femoral neck respectively. CONCLUSION: These results suggest that in patients with IPAA for ulcerative colitis, low BMD is not associated with vitamin D malabsorption and may be reversible after surgery.     

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.     

Management of desmoid tumors in patients after ileal pouch-anal anastomosis for familial adenomatous polyposis

PURPOSE: The aim of this study was to review the management of desmoid tumors in patients who have undergone ileal pouch-anal anastomosis for familial adenomatous polyposis and their outcome. METHODS: A retrospective review of case notes was undertaken in a series of 196 patients with familial adenomatous polyposis who had had an ileal pouch-anal anastomosis. Eleven patients were identified in whom desmoid tumor had developed (4 male; median age, 30 (range, 16-43) years). RESULTS: Desmoid tumors developed in the abdominal wall alone in 4 of 11 patients. Three enlarging tumors were resected with no subsequent recurrence. No patient received adjuvant treatment and pouch function remained stable at a median follow-up of eight years. Mesenteric desmoid tumors developed in seven patients; the pouch has been excised in two because of ischemia; two other patients have had defunctioning stomas created because of slow progression of their desmoid tumors. One patient had a single-lumen pouch excised and a new S-pouch inserted, with no subsequent recurrence of the desmoid tumor, and in two patients the mesenteric desmoid tumor has remained unchanged. All of these patients received long-term Clinoril (sulindac, Merck & Co., Inc., West Point, PA). Although there has been no significant deterioration in pouch function in patients in whom the pouch remains in situ, the pouch function was significantly worse compared with a control group of patients after ileal pouch-anal anastomosis for familial adenomatous polyposis in whom desmoid tumors did not develop. CONCLUSION: Desmoid tumors developed in 5.6 percent of 196 patients after ileal pouch-anal anastomosis for familial adenomatous polyposis. No patient with abdominal-wall desmoid tumor had a recurrence after local excision. By contrast, mesenteric desmoid tumors eventually resulted in pouch failure in four of seven affected patients.     

Comparison of the functional results of ileorectostomy and ileal pouch-anal anastomosis following total colectomy

To evaluate the functional results of continence reconstruction techniques following total colectomy, an analysis of long-term follow-up, quality of life parameters, and recurrence of basal disease was conducted on 17 patients who underwent ileal pouch-anal anastomosis, and 16 who underwent ileorectostomy. Satisfactory results were achieved in 29 of the 33 patients, partial results were achieved in 3, and only 1 remained totally incontinent. While this outcome was independent of the reconstruction technique, a lower mean daily frequency of defecation, better day-night distribution, faster definitive recovery from surgery, a higher degree of rehabilitation, and a lower frequency of unplanned outpatient visits, hospitalizations, and minor complications were achieved after ileorectostomy than after pouch-anal anastomosis. Furthermore, better results were observed in patients who had undergone surgery for familial polyposis or complicated diffuse colonic diverticulosis, compared to those who had undergone surgery for inflammatory bowel diseases (IBD). During the postcolectomy stage, tumor recurrence was found in 5 of 7 patients with familial polyposis and histologically confirmed malignancy, compared to only 1 of 6 patients with negative histological results. Extracolonic manifestations developed in two patients with ulcerative colitis, and a small bowel obstruction occurred in one with Crohn's disease. These findings emphasize the importance of carefully selecting patients for each type of continence reconstruction method after total colectomy according to their individual requirements.     

Radiology of ileal pouch-anal anastomosis: normal findings, examination pitfalls, and complications

Ileal pouch-anal anastomosis (IPAA) is a procedure in which an ileal reservoir is constructed after total colectomy and anastomosed to the anus. IPAA is a well-established option for patients who require surgery for chronic ulcerative colitis or familial adenomatous polyposis. Although excellent functional results can be achieved with IPAA, the procedure is associated with an appreciable number of complications, including small bowel obstruction, pouch fistula, anastomotic separation, anastomotic leakage, pelvic infection and abscess, stricture, and pouchitis. However, most of these complications do not require surgical intervention and can be managed with aggressive medical treatment and delay of ileostomy closure. Radiography of the IPAA pouch is routinely performed before closure of the diverting ileostomy to evaluate the integrity of the pouch and anastomosis. Such radiography can demonstrate many of the complications of IPAA, thus allowing identification of patients who may require intervention or delay before closure of the ileostomy.     

Results after restorative proctocolectomy and ileal pouch-anal anastomosis in patients with familial adenomatous polyposis and coexisting colorectal cancer

Although the operation of choice for patients with familial adenomatous polyposis (FAP) is restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA), its place in the management of patients with FAP and cancer has not been defined. The authors have reviewed their experience with these patients to determine the safety of IPAA and its efficacy as a cancer operation. The records of 55 patients with FAP who had undergone IPAA were examined. Follow-up studies included an annual questionnaire and physical examination. Eight patients had FAP with coexisting colorectal cancer. Median age at diagnosis was 25 (range 13-46) years, and at operation 33 (range 22-36) years. Of the eight patients (four men), four had colonic cancer and four had rectal cancer. Synchronous colorectal carcinoma was found in two patients. Staging according to the tumor node metastasis classification showed that five patients had stage 1 tumour, two had stage 2 and one had stage 3. Tumours were well, moderately or poorly differentiated in one, five and two patients respectively. During a median follow-up of 56 (range 14-98) months, metastasis developed in the liver of one patient 66 months after surgery. Two patients suffered complications: one had small bowel obstruction and the other mucosal prolapse. Tubular adenomas were found in the pouch of two patients and in the anal transitional zone of one. Pouch function is good to excellent in all surviving patients. Restorative proctocolectomy for patients with FAP and coexisting colorectal cancer can be undertaken with a favourable prognosis and function. It is compatible with curative intent.     

Comparing functional results one year and ten years after ileal pouch-anal anastomosis for chronic ulcerative colitis

Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the treatment of choice for most patients with chronic ulcerative colitis. Long-term results, however remain undefined; the major concern is that function may deteriorate. PURPOSE: The aim of this study was to assess functional outcome in a subgroup of patients who have an IPAA for chronic ulcerative colitis for > 10 years. METHODS: Among 1400 IPAA patients, 75 consecutive subjects (31 females and 44 males; median age 31 at operation) were identified who had the procedure prior to 1982. All patients had functional results recorded 1 year and 10 years following ileostomy closure. RESULTS: There were four deaths during the follow-up period; none were pouch related. Two patients refused ileostomy closure. Of the remaining 69 patients, there were 8 (11 percent) failures, leaving 61 subjects available for study. Stool frequency (7 +/- 3, mean +/- SD) remained unchanged. Of the 50 subjects with initially excellent daytime continence, 39 (78 percent) remained the same, 10 (20 percent) developed minor incontinence, and 1 developed poor control after 10 years. Four of 10 subjects (40 percent) with initial minor daytime incontinence remained unchanged, 4 (40 percent) improved, and 2 (20 percent) worsened. The one subject with poor control at one year was unchanged. Nocturnal fecal spotting increased over the 10-year period but not significantly (38 percent vs. 52 percent; P = 0.08). CONCLUSIONS: After IPAA, functional results in terms of stool frequency and rate of fecal incontinence did not deteriorate with time.     

Does the presence of a pre-ileostomy closure asymptomatic pouch-anastomotic sinus tract affect the success of ileal pouch-anal anastomosis?

Ileal pouch-anal anastomosis (IPAA) is the procedure of choice for patients with ulcerative colitis and familial adenomatous polyposis. This two-stage procedure with a temporary diverting ileostomy avoids the catastrophic consequences of anastomotic leakage. We set out to determine the incidence and effect of asymptomatic pouch sinuses detected prior to ileostomy closure on the outcome of IPAA. A total 1600 IPAAs performed at the Mayo Clinic were reviewed. Forty-one (2.6%) asymptomatic sinuses were treated expectantly. There were 22 males and 19 females who had a median age of 32 years (range 14 to 58 years). The median time to ileostomy closure was 5.9 months (range 4 to 11 months). Five patients required further surgery following closure of ileostomy. The pouch function in these five patients was similar to that in the remainder of the group. Patients with a persistent sinus at the time of ileostomy closure had the same function as the main cohort. This group had a median of five (range 2 to 12) stools during the day and two (range 0 to 4) at night. The total number of stools per 24 hours was seven (range 2 to 14). Frequent incontinence occurred in 9.7% and 7.3% during the day and at night, respectively. Only 2.4% (1/41) were disappointed with the results of the operation and 80.4% (33/41) found their quality of life improved. Functional outcomes were comparable to those achieved with uncomplicated IPAA. Radiologically detected asymptomatic sinuses can be treated expectantly with a low rate of pouch loss and subsequent surgery. This is not considered a serious setback inasmuch as long-term function and quality of life are comparable to that achieved with IPAA without sinus tracts.     

Influence of a defunctioning stoma on leakage rates after low colorectal anastomosis and colonic J pouch-anal anastomosis

BACKGROUND: Anal sphincter function is increasingly preserved following rectal excision for cancer and provides a better quality of life for patients than does a permanent colostomy. However, anastomotic complications may cause considerable morbidity and mortality. This retrospective study examined the incidence of anastomotic complications following two forms of reconstruction after resection for mid-rectal cancer: colonic pouch-anal anastomosis (CPAA) and low colorectal anastomosis (LCRA). METHODS: Some 258 consecutive patients with mid-rectal cancers between 6 and 11 cm from the anal verge underwent proctectomy with mesorectal excision and either CPAA or LCRA. The incidence of clinical and radiological leaks was determined in these patients who were considered in three groups: LCRA (defunctioning stoma), LCRA (no defunctioning stoma) and CPAA (all defunctioned). RESULTS: In the LCRA group without a defunctioning stoma, a clinical leak occurred in 17.0 per cent, compared with two of 30 in the LCRA group with a defunctioning stoma. In the CPAA group a clinical leak occurred in 4.9 per cent of patients, which was not significantly different from the rate in those with a defunctioned LCRA. Patients with a non-defunctioned LCRA were more likely to suffer a clinical anastomotic leak (P=0.01), peritonitis (P=0.001) and require unscheduled reoperation (P=0.006) than those with a defunctioned LCRA and/or CPAA. CONCLUSION: The use of a protective defunctioning stoma is advocated in conjunction with LCRAs.     

Physiological and functional outcome following ultra-low anterior resection with colon pouch-anal anastomosis

BACKGROUND: Low rectal cancer is usually managed by ultra-low anterior resection (ULAR) with total mesorectal excision and straight coloanal anastomosis. However, following this procedure patients often suffer from frequency, urgency of bowel action and, occasionally, faecal incontinence. To overcome such problems, a colon pouch may be fashioned and a subsequent colon pouch-anal anastomosis performed. The physiological and functional outcome following the use of a colon pouch are appraised. METHODS: All relevant papers identified from a Medline search and papers from cross-referencing were reviewed. RESULTS AND CONCLUSION: Creation of a colon pouch following ULAR results in reduced bowel frequency, and a lower incidence of urgency and faecal incontinence. Although there is a slightly increased incidence of evacuatory disorder and need for enemas or suppositories, this appears to be a minor problem which may possibly be overcome by using a smaller colon pouch. Compared with straight coloanal anastomosis following ULAR, the creation of a colon pouch produced a superior functional outcome.     

Ileal pouch-anal anastomosis as the first choice operation in patients with familial adenomatous polyposis: a ten-year experience

BACKGROUND: The choice between ileal pouch-anal anastomosis (IPAA) and ileorectal anastomosis (IRA) in the treatment of patients with familial adenomatous polyposis remains controversial. The aims of this study were to assess our 10-year experience with proctocolectomy, endoanal mucosectomy, construction of an ileal reservoir pouch, and IPAA in a series of 171 patients with familial adenomatous polyposis and to compare the functional results after IPAA with those after IRA. METHODS: Data from patients treated by IPAA at one institution were prospectively accumulated from October 1983 to October 1993. Medical records of 171 consecutive patients were studied regarding morbidity and functional results. These functional results were compared with those of a series of 23 patients who underwent IRA at the same institution. RESULTS: One patient (0.6%) died after operation. Sixty-two patients (36%) had concomitant colorectal carcinoma, 36 of which tumors were invasive (15 stage A, 13 stage B, and 8 stage C). Forty-six patients (27%) had at least one postoperative complication, with 14 patients requiring reoperation (8%). Twenty-six patients (15%) had obstruction. Seven patients (4%) had pelvic sepsis, and one had transient impotence (0.6%). Only two patients (1%) had a typical episode of pouchitis. The mean follow-up was 29 months (range, 3 to 100 months); 101 patients were monitored for more than 1 year. Little difference was noted between bowel function after IRA and that after IPAA. The mean daytime stool frequency after IPAA was 4.2 with 26% of patients having an average of 1 bowel movement at nighttime, compared with a stool frequency of 3.0 and 13% of patients having night evacuation after IRA. Daytime continence was normal for 98% of patients after IPAA and for all the patients after IRA. Nighttime continence was normal in 96% and 98% of patients, respectively. CONCLUSIONS: Morbidity and functional results after IPAA for familial adenomatous polyposis do not differ from those reported after IRA. For this reason and because of the risk of rectal cancer after ileorectal anastomosis, IPAA with endoanal mucosectomy is our first choice in the treatment of patients with familial adenomatous polyposis.     

Proctocolectomy with ileal W pouch anal anastomosis for ulcerative colitis

Restorative proctocolectomy with ileal pouch anal anastomosis, which is a relatively new procedure, has become a standard procedure for ulcerative colitis (UC) requiring surgical management. The main impact of this procedure is to cure patients of disease and to avoid permanent ileostomy, preserving better defecatory function and acceptable QOL. Some key aspects of our surgical procedure are as follows: 1) two or three separate staged operation, 2) W-shaped reservoir, 3) distal rectal mucosectomy and handsewn ileo-anal anastomosis, 4) short muscular cuff, and 5) temporary diverting ileostomy. Staged operation and diverting ileostomy are helpful to decrease risk of pelvic infection. Total removal of the rectal mucosa is necessary to cure the disease, and shorter muscular cuff decreases operating time and bleeding and thus the risk of pelvic sepsis. The W-shaped reservoir described by Nicholls brings both spontaneous defecation and improved function. We have adopted ileal W-pouch among several types of reservoir to 58 patients with UC since 1984, and found that a large and wide reservoir might allow better defecatory function. There were no cases of serious complications and no needs to remove the reservoir. Mean daily stool frequency was gradually decreased with time, and 4.9 stools per 24 hours at present day, and clinical score of neorectal function also gradually improved according to reduction of stool frequency. Seventy three percent of patients felt their defecatory function satisfactory and 89% of the patients recovered acceptable QOL no less than that obtained during the medically treated period.     

Restorative proctocolectomy with end to end pouch-anal anastomosis in patients over the age of fifty

This study was to examine whether 'fit' patients over the age of 50 who require elective surgery for ulcerative colitis are suitable candidates for restorative proctocolectomy, providing that they are continent before operation and that the anal sphincter is preserved in its entirety without stripping of the mucosa or endoanal anastomosis. Between 1986 and 1991, 18 patients 50 to 66 years old (median 55 years: nine men) underwent restorative proctocolectomy with end to end ileoanal anastomosis without mucosal stripping (12 quadruplicated (W), four duplicated (J), two no reservoir). The results were compared 12 (range three to 24) months later with those of 18 matched patients who were less than 50 years of age (median 34 years). In patients over 50, median resting anal pressure was 88 (range 44-131) cm water before and 80 (47-138) cm water after the operation (NS). In patients under 50, median resting anal pressure was 76 (51-128) cm water before and 77 (36-137) cm water after operation (NS). Resting anal pressure in older patients did not differ significantly from that in younger patients either before or after the operation. Both sensory and reflex anal functions were preserved as well after operation in the older patients as in the younger ones. The clinical results in patients over 50 were slightly inferior to the results for the younger patients, but the difference was small and not significant. Hence age alone is not a contraindication to restorative surgery provided that the anal sphincter is preserved in its entirety.     

Masked polycythaemia vera in a patient with extrahepatic portal venous obstruction

Myeloproliferative disorder (MPD) is an important cause of thrombosis of the hepatic and portal venous system. The diagnosis in many of these patients is missed as they have an atypical clinical presentation and may have a normal haematological profile at presentation. We report a 30-year-old patient with features of portal hypertension due to extrahepatic portal venous obstruction. She had a normal haemoglobin level and haematocrit at presentation, but the red cell mass was found to be elevated even in the presence of low serum iron levels. A diagnosis of polycythaemia vera as the underlying disease was made.