Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Proctocolectomy, Restorative”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75Linked to original sources
PubMed1998

Intraoperative abandonment of ileal pouch to anal anastomosis--the Mayo Clinic experience.

BACKGROUND: Completion of the ileal pouch to anal anastomosis (IPAA) is neither always possible nor advisable based on intraoperative findings. This study was undertaken to document the incidence of and reasons for intraoperative abandonment of IPAA in a series of over 1,700 attempts. STUDY DESIGN: A retrospective review of the Mayo Clinic surgical index from January 1981 through December 1995. Patients with the preoperative diagnosis of chronic ulcerative colitis or familial adenomatous polyposis for whom IPAA was planned but not completed are the subject of this report. Comparison is made to patients with a completed IPAA from the Mayo Clinic IPAA registry. RESULTS: During a 15-year period, 1,789 IPAA attempts were made. Intraoperative abandonment occurred in 74 (4.1%). Patients in whom the operation was abandoned were older than patients in whom it was not (38 versus 33 years, p < 0.01), with age older than 40 years conferring a relative risk of 1.87 versus age younger than 40 (95% confidence interval, 1.19-2.94%). IPAA was abandoned for technical reasons in 32 (43%), intraoperative diagnosis of Crohn's disease in 27 (36%), colorectal cancer in 10 (14%), mesenteric desmoid in 3 (4%), and miscellaneous reasons in 2 (3%) patients. Fifty-one (69%) patients underwent proctocolectomy and ileostomy and 23 (31%) underwent sphincter preserving procedures. Of these, 2 underwent subsequent successful IPAA. CONCLUSIONS: Preoperative counseling for IPAA should include discussion of the risk of intraoperative abandonment (4.1%). Older patients are at increased risk. If the IPAA is abandoned for reversible reasons, preservation of the anal sphincter preserves the option of a subsequent IPAA.

Adenomatous Polyposis Coli↗
PubMed1998

Surgical management of left colon obstruction: the University of Minnesota experience.

BACKGROUND: Management of left-sided colonic obstruction is a surgical challenge. This study was performed to review our management of patients with left colon obstruction presenting to the University of Minnesota Hospitals over a 10-year period, 1985 to 1994. STUDY DESIGN: We did a retrospective chart review of 143 patients (48 male and 95 female; mean age 70 years). RESULTS: Sites of obstruction were rectosigmoid, 40%; sigmoid colon, 47%; descending colon, 5%; and splenic flexure, 8%. Fifty-two percent of patients had obstructing colorectal cancer. Two patients presented with generalized peritonitis secondary to colonic perforation. The majority (n = 121, 85%) of patients underwent resection (subtotal in 39 [32%], and segmental in 82 [68%]) and anastomosis in a single stage after appropriate resuscitation. Intraoperative colonic cleansing was undertaken in 40 patients (28%). Morbidity within 30 days of operation was 11%, including 1 anastomotic leak, and mortality was 3%. The 4 deaths occurred in patients over 75 years of age and were not from anastomotic complications. CONCLUSIONS: A single stage resection and an anastomosis facilitated by intraoperative colonic cleansing in one-third of cases was performed in 85% of patients presenting with left colon obstruction. One anastomotic leak occurred. Our current policy of strongly favoring a single stage, definitive operation for patients presenting with left colon obstruction appears reasonable on the basis of this retrospective review of our experience.

Adult↗
PubMed1998

Longterm outcomes and quality of life after Z-shaped anastomosis for Hirschsprung's disease.

BACKGROUND: Z-shaped anastomosis is one of the modifications of Duhamel's procedure that was designed to eliminate the blind rectal pouch and to achieve complete resection of the colorectal septum. It has been the most widely performed operation in Japan for many years. The longterm postoperative function of evacuation and quality of life of the patients are considered important to evaluate this procedure. METHODS: At Kyushu University Hospital, from 1963 to 1997, 127 patients with Hirschsprung's disease underwent Z-shaped anastomosis. As a result, 122 out of 127 patients (96%) survived. The present status and symptoms, and anorectal functions, including a manometric study and barium enema, were evaluated during the clinical followup. RESULTS: A total of 99 of the 122 surviving patients (81%) were available for this study, and the mean postoperative period was 16 years. Evacuation scores in all patients were as follows; excellent, 62.2%; good, 28.6%; fair, 8.2%; and poor, 1.0%. The percentage of the patients who showed severe symptoms was 4.1% for diarrhea, 3.1% for constipation, 5.1% for incontinence, and 7.1% for soiling. The evacuation score improved chronologically and tended to reach a plateau at 10 to 15 years after operation, at which time 73% of the patients showed excellent outcomes and 95% were satisfactory (good or excellent). The appearance of a sense of defecation and an increase in the pressure difference between the anal canal and the rectum substantially contributed to the improvement in the defecation score. The appearance of the rectosphincteric reflex, including the atypical one, was seen in 40.5% of patients, but the appearance of a reflex did not seem to be related to the clinical status of defecation. Twenty-two of 30 patients older than 20 years were married, and 8 patients had children. CONCLUSIONS: The evacuation scores of in-patients undergoing Z-shaped anastomosis improved with age and were satisfactory (good or excellent) in most patients at least 10 years after operation. Most of the patients adapted to a normal social life.

Adolescent↗
PubMed1999

Surgical treatment of anoperineal Crohn's disease: can abdominoperineal resection be predicted?

BACKGROUND: Anoperineal Crohn's disease (APCD) runs an unpredictable course. Although this course is relatively benign in most patients, some will eventually require abdominoperineal resection (APR). The aim of this study was to identify prognostic factors of longterm APR in patients with APCD. STUDY DESIGN: From 1980 to 1996, 119 patients were operated on for APCD (mean +/- SD age 30 +/- 13 years; range 11 to 96 years). Patients were divided into two groups: those undergoing APR and patients without APR at the end of followup. The following prognostic criteria were studied: (1) age at onset of Crohn's disease (CD) and at the first manifestation of APCD, gender, APCD as the first manifestation of CD, and interval between the onset of CD and the first manifestation of APCD; (2) for the first manifestation of APCD, the type and number of lesions and the results of surgical treatment; and (3) associated intestinal localizations of CD and the type and number of manifestations of APCD during followup. RESULTS: Mean followup from the first manifestation of APCD was 93 months (range 1 to 398 months). At the end of followup, 30 patients had undergone APR (25%). Logistic regression analysis showed that four criteria seemed to be associated with an increased risk of APR: age at first APCD (p < 0.02), fistula as the first manifestation of APCD (p < 0.04), more than three APCD lesions during followup (p < 0.01), and rectal involvement by CD (p < 0.000001). When, as in eight patients, these criteria were all present, APR was performed during followup in 100% of patients. In the absence of all four criteria (eight patients), APR was never performed. CONCLUSIONS: This study allowed us to identify patients with APCD at high risk of APR. For these patients, early prevention of CD recurrence should be attempted by aggressive medical therapy.

Adolescent↗
PubMedDate not supplied

The jejunal pouch as a rectal substitute after proctocolectomy.

Our hypothesis was that a jejunal pouch used as a rectal substitute after proctocolectomy would slow enteric transit, delay defecation, and decrease stool frequency compared to an ileal pouch so used. Twelve dogs underwent proctocolectomy; six had a jejunal pouch-distal rectal anastomosis and six had an ileal pouch-distal rectal anastomosis. After recovery, postprandial mouth-to-anus transit was slower in jejunal pouch dogs (253 +/- 18 minutes [mean +/- SEM]) than in ileal pouch dogs (112 +/- 7.9 minutes; P <0.05). Moreover, jejunal pouch dogs passed only 4.1 +/- 0.3 stools during the 12 hours after eating, whereas ileal pouch dogs passed 6.3 +/- 0. 9 stools (P <0.05). The mean frequency of proximal ileal pacesetter potentials after feeding was less in jejunal pouch dogs (12 +/- 0.4 cycles/min) than in ileal pouch dogs (16 +/- 0.3 counts/min; P = 0. 01), and jejunal pouches had more action potentials (jejunal = 82% +/- 4.3% of pacesetter potentials had action potentials, ileal = 61% +/- 3.0%; P <0.05). In contrast, gastric emptying and pouch motility, emptying, mucosal integrity, and bacteriologic and histologic properties were similar in the two groups of dogs. We concluded that the jejunal pouch operation slowed enteric transit, delayed defecation, and decreased postprandial stooling compared to the ileal pouch operation.

Animals↗
PubMedDate not supplied

Perioperative resting pressure predicts long-term postoperative function after ileal pouch-anal anastomosis.

The purpose of this study was to determine whether perioperative manometry is useful in predicting long-term functional status after ileal pouch-anal anastomosis (IPAA). Prospectively collected perioperative anal manometry data from 1439 patients undergoing IPAA from 1986 to 2000 were compared to postoperative functional status at various time intervals from 6 months to 8 years after IPAA. A validated questionnaire was used to obtain information regarding restrictions of diet, work, social and sexual activity, urgency, fecal seepage or incontinence, energy level, satisfaction with surgery, and quality of life. The presence of seepage and the degree of incontinence were compared to the patient's perceived quality of life, health, energy level, and satisfaction with surgery. Low (<40 mm Hg) pre- and postoperative resting pressures were associated with increased seepage, pad use, and incontinence. Patients with low resting pressures also reported diminished quality of life, health, energy level, and satisfaction with surgery. There was a significant association (P < 0.001) between seepage and degree of incontinence and quality of health, quality of life, energy level, and level of satisfaction with surgery. Perioperative resting anal sphincter pressures greater than 40 mm Hg are associated with significantly better function and quality of life after ileal IPAA. Improved functional outcome is associated with better quality-of-life outcomes. Low preoperative resting pressures do not preclude successful outcome after IPAA.

Anal Canal↗
PubMedDate not supplied

Enhancing release of peptide YY after near-total proctocolectomy: jejunal pouch vs. ileal pouch-distal rectal anastomosis.

Reconstructing the enteric tract after near-total proctocolectomy by interposing a jejunal pouch between the distal ileum and the distal rectum slows small intestinal transit and decreases the number of stools per day compared to a conventional ileal pouch-distal rectal reconstruction. Our hypothesis was that the jejunal pouch operation brings about these results by protecting the ability of the ileal mucosa to secrete peptide YY, thus augmenting the hormonal ileal brake on small intestinal transit and decreasing the stool frequency. In five jejunal pouch dogs and five ileal pouch dogs, more than 6 months after the operation, serum peptide YY concentrations were determined before and at 30-minute intervals for 180 minutes after a standard meal. Fasting serum concentrations of peptide YY, measured by radioimmunoassay, were greater in jejunal pouch dogs (mean +/- SEM, 1340 +/- 143 pg/ml) than in ileal pouch dogs (804 +/- 52 pg/ml; P < 0.01). Postprandial peptide YY concentrations in jejunal pouch dogs were also greater at 30 minutes (jejunal pouch = 1524 +/- 131 pg/ml, ileal pouch = 913 +/- 67 pg/ml; P = 0.01) and 60 minutes after the meal (jejunal pouch = 1723 +/- 250 pg/ml, ileal pouch = 1001 +/- 70 pg/ml; P = 0.05) and peaked sooner (jejunal pouch = 81 +/- 17 minutes, ileal pouch = 147 +/- 12 minutes; P = 0.01). We concluded that the jejunal pouch operation results in greater ileal fasting and postprandial secretion of peptide YY than the ileal pouch operation. The greater release may account, in part, for the slower small bowel transit and decreased number of stools after the jejunal pouch operation.

Anal Canal↗
PubMedDate not supplied

Bile acid absorption after near-total proctocolectomy in dogs: ileal pouch vs. jejunal pouch-distal rectal anastomosis.

Bile acid malabsorption is often present in patients after near-total proctocolectomy and ileal pouch-anal canal anastomosis, suggesting ileal dysfunction. Experiments were performed in dogs to compare bile acid absorption after a modified procedure, in which a jejunal pouch was interposed between the terminal ileum and the distal rectum, with that after a conventional ileal pouch operation. Fecal bile acid output (equivalent to hepatic bile acid biosynthesis) and composition were determined by gas chromatography/mass spectrometry in five jejunal pouch dogs and in five ileal pouch dogs more than 6 months after operation. Fecal bile acid output in the jejunal pouch dogs (mean +/- standard deviation) was 215 +/- 59 mg/day (10.1 +/- 2.7 mg/kg-day), a value similar to that obtained in the ileal pouch dogs (261 +/- 46 mg/day [12.8 +/- 3.1 mg/kg-day]; P >0.05). These values were also similar to those reported by others for healthy unoperated dogs, indicating that increased bile acid biosynthesis occurring in response to bile acid malabsorption was not present. Fecal bile acids in pouch dogs were completely deconjugated and extensively 7-dehydroxylated (jejunal pouch = 90.4% dehydroxylated; ileal pouch = 88.6% +/- 6.6% dehydroxylated) and consisted predominantly of deoxycholic acid derivatives. We conclude that when either a jejunal pouch or an ileal pouch is used as a rectal substitute in dogs, an anaerobic pouch flora develops that efficiently deconjugates and dehydroxylates bile acids, rendering them membrane permeable. The resultant passive absorption of unconjugated bile acids appears to compensate for any loss of active ileal absorption of conjugated bile acids, and bile acid malabsorption does not occur.

Absorption↗
PubMed2003

Colonic metaplasia in the ileal pouch is associated with inflammation and is not the result of long-term adaptation.

Ileal pouch-anal anastomosis (IPAA) is the preferred surgical therapy for chronic ulcerative colitis (CUC) and familial adenomatous polyposis (FAP). Previous studies have demonstrated morphologic changes in pouch mucosa such as villous atrophy and crypt hyperplasia. These changes have been labeled "colonic metaplasia." The aims of this study were to determine whether these changes represent "normal" long-term adaptation of the nondiseased pouch or instead are present only in the setting of inflammation. Twenty-four patients were identified, greater than 5 years status post-IPAA for CUC, who underwent pouchoscopy for surveillance and had no history of pouchitis. Thirty-one patients were identified greater than 5 years status post-IPAA for CUC, who had a history of pouchitis and had undergone pouchoscopy at least 5 years status post-IPAA. Eight patients status post-IPAA for FAP were also identified. Biopsy specimens were reevaluated by a single, blinded pathologist for degree of inflammation, the presence of villous atrophy and crypt hyperplasia, and evidence of dysplasia. Among the patients with CUC, the inflammation score was greater in the pouchitis group, 13.2 +/- 1.2, compared to the nonpouchitis group, 4.0 +/- 0.5 (P < 0.0001). Median colonic metaplasia score was greater in the pouchitis group (4 [range 2 to 6]) vs. 2 (9 [range 0 to 6]; P < 0.0001). The colonic metaplasia score correlated with the inflammation score (Spearman coefficient r = 0.83; P < 0.0001). In the eight patients with FAP, the inflammation score was 5.1 +/- 0.9 and the median colonic metaplasia score was 1 (range 0 to 4). There was no evidence of dysplasia in any of the biopsy specimens. Patients without a history of pouchitis or symptoms of pouchitis have only a minimal degree of villous atrophy and crypt hyperplasia. These morphologic changes in the ileal pouch are found primarily in the setting of inflammation, and likely represent a reparative response.

Adaptation, Physiological↗
PubMedDate not supplied

Proctocolectomy with jejunal pouch-distal rectal anastomosis: an alternative to ileal pouch reconstruction.

The aim of this study was to determine whether a jejunal pouch would have a lower resting pressure, be more distensible, and have more interdigestive migrating myoelectric complexes and less fecal bacterial overgrowth than would an ileal pouch after proctocolectomy and pouch-distal rectal anastomosis. In six conscious dogs with a jejunal pouch-distal rectal anastomosis and six with an ileal pouch-distal rectal anastomosis (controls), pouch distensibility and motility were measured using a barostat and perfused pressure-sensitive catheters passed per anum, pouch electrical activity was recorded using chronically implanted electrodes, and the number of bacteria per gram of stool was assessed by culture. Dogs with a jejunal pouch had lower resting pouch pressures, more distensible pouches, faster frequencies of pacesetter potentials in the pouch, more phase 3 intervals of the interdigesive migrating myoelectric complex reaching the pouch, but similar numbers and types of bacteria in their stools compared to the dogs with an ileal pouch. We concluded that jejunal pouches have a lower resting pressure, are more distensible, have more cleansing contractions, but a similar fecal flora compared to ileal pouches. A jejunal pouch has features that make it an attractive alternative to an ileal pouch for pouch-distal rectal or pouch-anal canal anastomosis after proctocolectomy.

Animals↗
PubMedDate not supplied

Discontinuous appendiceal involvement in ulcerative colitis: pathology and clinical correlation.

Continuous mucosal involvement from the rectum proximally is one of the hallmarks of ulcerative colitis. However, recent pathologic series report appendiceal ulcerative colitis in the presence of a histologically normal cecum, representing a "skip" lesion. The clinical significance of this finding has not been established. Eighty patients, 54 males and 26 females, average age 37.9 years (range 14 to 82 years) who underwent proctocolectomy for ulcerative colitis from January 1990 to September 1995 were examined to determine the rate of discontinuous appendiceal involvement. Excluded were 12 patients with prior appendectomy and 11 with fibrotic obliteration of the appendiceal lumen. Of the remaining 57 patients, seven (12.3%) had clear appendiceal involvement in the presence of a histologically normal cecum. These seven patients clinically were indistinguishable from the 50 patients without skip involvement of the appendix in terms of age at surgery, pretreatment medications, type of surgery, interval from diagnosis to definitive procedure, complications, functional results, and clinical course. Discontinuous appendiceal involvement was found in 12.3% of patients undergoing proctocolectomy for ulcerative colitis, and clinically these patients behave as those without this feature.

Adolescent↗
PubMedDate not supplied

The continent ileostomy: long-term durability and patient satisfaction.

The long-term results of the continent ileostomy are controversial. Durability and patient satisfaction were evaluated by analyzing the outcome in 129 consecutive patients who had a continent ileostomy performed by one surgeon at the University of California, San Francisco, between 1975 and 1995. A quality-of-life questionnaire was sent to all patients for whom addresses were available (n = 121). Late outcome data could be obtained for 85 (66%) of the 129 patients. Three of the 85 patients died with their continent ileostomies but of unrelated causes. Fifty-one (60%) of 85 patients currently have the continent ileostomy (group A) (mean 15.1 years, range 2.7 to 21.7 years), whereas 31 (36%) of 85 have undergone conversion of continent ileostomy to conventional ileostomy (group B) (mean 5.4 years, range 0.2 to 20.4 years). Patients in group A underwent fewer major postoperative revisions (mean 0.7, range 0 to 4) than patients in group B (mean 1.3, range 0 to 8) (t test, P = 0. 088). The indications for pouch removal included valve dysfunction (42%), refractory pouchitis (23%), multiple fistulas (26%), Crohn's disease (6%), and other (16%) (four patients had two indications). Eighty-seven percent of survey respondents in group A considered their present state of health to be better than before their continent ileostomies. Fifty-seven percent and 82% of respondents in group A were not limited at all in regard to vigorous or moderate activity, respectively. Although in approximately one third of patients the pouch had to be removed, 97% of the remaining two thirds have a good to excellent outcome.

Adenomatous Polyposis Coli↗
PubMedDate not supplied

Ileal pouch salvage following failed ileal pouch- anal anastomosis.

Attempts have been made to salvage failed ileal pouch-anal anastomoses (IPAA) performed for ulcerative colitis or familial polyposis coli. These can be categorized as total reconstruction of the IPAA, partial transabdominal approach, and partial transperineal approach. The aims of our study were to determine the overall success of pouch salvage; to examine the demographics, indications, and outcomes for each approach; and to assess anorectal physiology and patient satisfaction in those with successful salvage operations. We reviewed data, including results of anorectal manometry, from 29 patients undergoing salvage procedures for failed IPAA. Seventeen salvage attempts were successful, 11 attempts failed, and one patient was lost to follow-up. Success rates were 100% in the total reconstruction group, 25% in the partial transabdominal group, and 55% in the transperineal group. In those undergoing total reconstruction of the IPAA (n = 9), functional outcome, as measured by incontinence, improved with 50% reporting incontinence preoperatively compared to 0% postoperatively (P = 0.055). Mean 24-hour stool frequency and nighttime stool frequency declined. All patients reported satisfaction with their outcomes. Sixty percent of patients who underwent ileal pouch salvage following IPAA have been successful in avoiding permanent ileostomy. These results suggest that a continued effort to salvage failed IPAA, including the use of total reconstruction, is a viable alternative to permanent ileostomy.

Adenomatous Polyposis Coli↗
PubMed2003

Risk of fracture in ulcerative colitis: a population-based study from Olmsted County, Minnesota.

BACKGROUND & AIMS: Osteopenia is common in patients with ulcerative colitis (UC), but less is known about fracture risk. Previously we were unable to demonstrate increased fractures in a population-based cohort with Crohn's disease. METHODS: Medical records of 273 Olmsted County, Minnesota residents initially diagnosed with UC in 1940-1993 were reviewed for evidence of subsequent fractures, as were records of a control cohort of county residents matched on age and gender. Cumulative fracture incidence after diagnosis was estimated by using the Kaplan-Meier method. The hazard ratio of fracture in cases relative to control subjects was estimated by Cox proportional hazards regression, which was also used to evaluate potential risk factors for fracture. RESULTS: Median follow-up was 13 years (range, 1 day-53 years). The cumulative incidence of any fracture from time of diagnosis was 40% at 25 years versus 42% in control subjects (P=0.615). The hazard ratio in cases compared to control subjects was 1.1 (95% confidence interval, 0.8-1.6) for any fracture and 1.3 (95% confidence interval, 0.6-2.8) for any osteoporotic fracture (hip, spine, or wrist as a result of moderate trauma). Other causes of secondary osteoporosis were associated with increased fracture risk, whereas estrogen use was protective. One hundred three cases received any corticosteroids (38%), and 34 (12%) had taken corticosteroids for 6 months or longer. Corticosteroids and bowel resection were not associated with fracture risk. CONCLUSIONS: In this population-based cohort of patients with UC, fracture risk was not elevated relative to matched community control subjects. Use of corticosteroids did not appear to significantly influence the risk of fracture.

Adolescent↗
PubMed2005

Differentiating risk factors for acute and chronic pouchitis.

BACKGROUND & AIMS: Pouchitis is the most common complication of ileal pouch anal anastomosis in patients with ulcerative colitis. In some cases the inflammation becomes chronic and requires long-term medical therapy. The clinical course and medical therapy are different between acute pouchitis and chronic pouchitis. The aim of this study was to determine if there are predictors of risk for acute vs. chronic pouchitis. METHODS: Patients with acute pouchitis (N = 40) and patients with chronic pouchitis (N = 40) were matched with a control group who never had pouchitis (N = 40). Data were collected for multiple pre-, peri-, and postoperative factors and follow-up telephone calls were performed. Case-control univariable analyses and multivariate logistic regression were used to measure the association between covariates and pouchitis. RESULTS: Multivariate logistic regression showed that extensive colonic disease (odds ratio [OR], 2.99; P = .045 for acute pouchitis; and OR, 4.61; P = .010 for chronic pouchitis) and extraintestinal manifestations (OR, 2.88; P = .037 for acute pouchitis; and OR, 2.69; P = .047 for chronic pouchitis) were associated with both acute and chronic pouchitis. Postoperative nonsteroidal anti-inflammatory drug (NSAID) use was associated with chronic pouchitis, but less so with acute pouchitis. Patients with fulminant colitis as an indication for surgery had a decreased risk for developing chronic pouchitis (OR, 0.22; P = .036), but no such association was seen for acute pouchitis. CONCLUSIONS: Extensive colonic disease and preoperative extraintestinal manifestations are associated with increased risk for both acute and chronic pouchitis. Fulminant colitis leading to colectomy is protective from development of chronic pouchitis. Postoperative use of NSAIDS is a risk factor for chronic pouchitis and possibly for acute pouchitis, and thus should be discouraged for patients who undergo ileal pouch anal anastomosis.

Acute Disease↗
PubMed2003

Electrolyte profiles within the ileoanal pouch: measurement by an in vivo equilibrium dialysis technique.

BACKGROUND: Patients with an ileoanal pouch have high rates of fluid and electrolyte loss. These improve with pouch adaptation. There is limited information concerning secretion and absorption in the stable ileoanal pouch. A new method to measure and characterize electrolytes in the ileoanal pouch is described. METHODS: Following an in vitro study, nine patients with a stable ileoanal pouch had consecutive placement of dialysis bags consisting of a semi-permeable membrane containing 5 ml of 10% dextran in normal saline into the ileoanal pouch. These were left in place for 15, 30, 60, and 120 min. After determining that 60 min was the optimal timing for measurement of electrolyte concentrations, 12 normal volunteers underwent a similar in vivo dialysis study with dialysis bags withdrawn at 60 min. Sodium, chloride, potassium, phosphorus, calcium and magnesium concentrations in the dialysis bags were compared between the two groups. RESULTS: In the in vitro and in vivo studies, the measured electrolytes reached equilibrium within 60 min. Statistically significant differences between sodium concentrations (160.9 +/- 30.2 vs. 116.8 +/- 13.8 mmol/l, respectively) and phosphorus concentrations (6.8 +/- 5.2 vs. 1.8 +/- 0.7 mg/dl, respectively) at 60 min in ileoanal pouch patients and volunteers were found (p<0.001). There were no statistical differences in the other measured electrolytes between the two groups. CONCLUSION: An in vivo dialysis technique is described for measuring electrolyte concentrations within the ileoanal pouch. Differences in sodium and phosphate concentrations may reflect incomplete adaptation of the ileoanal pouch, and are a potential explanation for increased stool frequency in these patients.

Adult↗