Joan E. Blair

The ileal reservoir and ileoanal anastomosis procedure

A retrospective review was undertaken to determine factors important in predicting functional results following the ileal reservoir and ileoanal anastomosis procedure. One hundred seventy-nine patients underwent ileal reservoir and ileoanal anastomosis at the University of Toronto between December 1981 and January 1987. One hundred sixty-three patients had ulcerative colitis, 11 had familial adenomatous polyposis, and five had Crohns disease. A J-reservoir was constructed in 72 patients and an S-reservoir in 107 patients. Functional results were assessed in 102 patients who had had their loop ileostomies closed for more than one year. The most significant technical complications were anal anastomotic leaks (10 percent), reservoir anastomotic leaks (3.9 percent), anal anastomotic stricture (7.8 percent), late fistula-inano (2.8 percent), small-bowel obstruction (19 percent), and loop ileostomy complications (23 percent). Overweight males and patients with operative blood loss greater than 1000 cc developed anal stricture more frequently (P<.005). Patients who had a stapled J-reservoir had a higher rate of reservoir leak. The average number of bowel movements reported by patients for 24 hours was 6.2±3.1. Only ten (9.8 percent) patients had to intubate their reservoir to empty it. Urgency was experienced by 24 patients and soilage at night by 23 (22.5 percent) and during the day by 18 (17.6 percent). Seven patients (6.8 percent) were incontinent during the night and only one during the day. Pouchitis was reported in 16 patients (15.7 percent). Patients with anal anastomotic stricture had more urgency and pouchitis, and had to intubate their reservoir more frequently (P<.05). No other factors analyzed affected technical or functional results.

Ultrastructural Evidence for Piecemeal and Anaphylactic Degranulation of Human Gut Mucosal Mast Cells in vivo

One hundred and seventeen coded intestinal biopsies were examined by electron microscopy and evaluated for morphological evidence of mast cell and basophil secretion in situ. Sixty percent of the biopsies had evidence of secretion. Mast cell secretion was evident in control biopsies, many of which were obtained from uninvolved tissues of patients with inflammatory bowel disease. Biopsies of inflamed continent pouches from ulcerative colitis (UC) patients showed more mast cell secretion than noninflamed UC pouch biopsies. This evidence of mast cell secretion supports recent work that documents high constitutive levels of histamine in jejunal fluids of Crohns disease patients and suggests a proinflammatory role for mast cells in inflammation associated with pouchitis.

Ultrastructural identification of exocytosis of granules from human gut eosinophils in vivo.

Twenty-two percent of 117 biopsies of human intestinal tissues had ultrastructural images of classical regulated secretion from eosinophils in vivo i.e. eosinophil granule extrusion (EGE). Replicate intestinal biopsies that were positive for bacteria had EGE more often than not (p < 0.05); 77% of the isolates were Staphylococci. Some of the intestinal biopsies also had damaged nerves; all that had EGE and damaged enteric nerves also had positive bacterial cultures. The EGE that we observed could not account for all enteric nerve damage, suggesting multifactorial mechanisms for nerve damage in gut tissues. Among the possibilities are release of neurotoxic eosinophil granule proteins by an alternate secretory route, i.e., piecemeal degranulation, direct toxicity of tissue invasive bacteria and/or damaged nerves of unknown etiology such as those that are regularly present in uninvolved tissues of patients with Crohns disease.

Human Gut Mucosal Mast Cells: Ultrastructural Observations and Anatomic Variation in Mast Cell-Nerve Associations in vivo

One hundred and seventeen coded intestinal biopsy specimens were examined by electron microscopy. All surgical biopsies were obtained from uninvolved sites of patients with two inflammatory bowel diseases (ulcerative colitis or Crohns disease) and from patients with preneoplastic and neoplastic diseases (adenocarcinoma, rectal polyp, familial polyposis). Biopsy sites included normal ileum, colon, and rectum as well as conventional ileostomies and continent pouches constructed from the ileum. The data reported here describe the ultrastructural anatomy of human gastrointestinal tract mucosal mast cells in vivo and their anatomic associations with enteric nerves.

Axonal necrosis of enteric autonomic nerves in continent ileal pouches. Possible implications for pathogenesis of Crohn's disease.

OBJECTIVE Axonal necrosis was first described in samples of small intestine from patients with Crohns disease (A.M. Dvorak et al. Hum Pathol 1980; 11:620-634). Clinically evident inflammation of continent ileal reservoirs (pouches) has clinical features that resemble Crohns disease. Possible similarities in the pathogenesis of Crohns disease and pouchitis were sought using ultrastructural and microbiologic tools to identify damaged enteric nerves and tissue bacteria. METHODS An encoded ultrastructural and microbiologic study of replicate biopsies from 114 samples of human intestine was done. Biopsies from ileum, colon, conventional ileostomy or continent pouch were obtained from patients with ulcerative colitis, Crohns disease, or familial polyposis and grouped into three clinical study groups (control, normal pouch, pouchitis), based on clinical and endoscopic criteria. Biopsies were prepared for electron microscopy with standard methods; replicate biopsy samples were washed extensively before preparing cultures designed to identify aerobic as well as facultative and obligate anaerobic bacteria (Onderdonk et al. J Clin Microbiol 1992; 30:312-317). The ultrastructural diagnosis of damaged enteric nerves was based on previously published criteria for axonal necrosis (A.M. Dvorak and W. Silen. Ann Surg 1985; 201:53-63). Intergroup comparisons were tested for significance using Chi-square analysis. RESULTS The highest incidence of axonal necrosis was present in Crohns disease control biopsies (53%), regardless of whether bacteria were present (or not) in cultures of replicate biopsies. Axonal necrosis also occurred in more ulcerative colitis and familial polyposis biopsies (regardless of biopsy site) that had positive bacterial cultures than in those that did not (p < 0.001). In addition, axonal necrosis was documented in 42% of the pouch biopsies from ulcerative colitis and familial polyposis patients, particularly in those pouches that were found to be inflamed by clinical criteria and that also had positive bacterial cultures of the biopsied tissues. Control biopsies from patients with ulcerative colitis and familial polyposis had significantly less nerve damage than pouch biopsies in the presence of positive cultures (p < 0.01). Among the clinically inflamed pouches biopsied in ulcerative colitis or familial polyposis patients, we found that none had damaged enteric nerves when bacterial cultures were negative (p < 0.005). If the presence of axonal necrosis alone was compared with the presence of undamaged enteric nerves in all biopsies from patients with ulcerative colitis, a highly significant number of ulcerative colitis biopsies with axonal necrosis occurred in pouches (72%) compared with controls (p < 0.001). CONCLUSIONS The ultrastructural finding of axonal necrosis in Crohns disease confirms previous studies. The presence of damaged enteric nerves in patients with pouchitis provides ultrastructural support to the clinical impression of similarities between pouchitis and Crohns disease. The association of damaged nerves and invasive bacteria in pouchitis suggests mechanistic similarities for the pathogenesis of Crohns disease that requires further investigation.

Histologic and microbiologic features of biopsy samples from patients with normal and inflamed pouches

PURPOSE: This study was undertaken to assess the electron microscopic and microbiologic findings in tissue biopsy samples from patients with pouchitis and to compare them with findings in patients with normal pouches, conventional ileostomies, and normal ileum. METHODS: Tissue samples were obtained from 78 patients: 23 patients with normal pouches endoscopically and histologically (Group 1), 12 patients with endoscopic and histologic evidence of inflammation (pouchitis) (Group 2), 14 patients who had either endoscopic or histologic evidence of inflammation but not both (Group 3), 20 patients with conventional ileostomies (Group 4), and 9 patients without ileostomies from whom biopsy samples of normal ileum were obtained (Group 5). RESULTS: The mean total aerobic facultative counts in the biopsy samples from the pouchitis patients were significantly higher when compared with biopsy samples from Groups 4 and 5 (P<0.05). There were no significant differences in the mean anaerobic counts among the five groups. Positive cultures were obtained in 90 percent of patients with pouches compared with 69 percent of patients with conventional ileostomies or normal ileum (P<0.05). Intramural bacteria were observed on electron microscopy in biopsy specimens of 47 percent patients with pouches compared with 14 percent of patients with conventional ileostomies or normal ileum (P<0.05). However, the proportion of patients with positive cultures or intramural bacteria was not increased in the pouchitis group compared with the normal pouch group. CONCLUSION: These data suggest that intramural aerobic facultative bacterial counts are elevated in patients with pouchitis and may play a role in the pathogenesis of pouchitis.

The Release Profile of a Controlled Release Preparation of 5-Aminosalicylic Acid (Rowasa I| in Humans

Abstract5-Aminosalicylic acid and its metabolite, N-ac-5-ASA, were measured in the plasma, urine, and ileostomy effluent of 24 ileostomates who ingested 750 mg Rowasa I® following an overnight fast. Twelve subjects previously had a small-bowel resection or had part of their small bowel out of circuit (mean 95 cm) (Group I) while 12 had an intact small bowel (Group II). The mean peak plasma concentration of N-ac-5-ASA was 1.11μg/ml in Group 1 subjects compared with 2.80μg/ml in Group II subjects (P=N.S.). On average, 53.0 percent of the ingested Rowasa I was detected in the 24-hr ileostomy effluent of Group I subjects compared with 45.3 percent in the Group II subjects (P=N.S.). The mean recovery of 5-ASA and N-ac-5-ASA in urine was 8.5 percent in Group I and 35.6 percent in Group II subjects (P<0.001). These studies demonstrate that 5-ASA is released and present in the small bowel following oral ingestion of Rowasa I in patients who have or have not had small bowel resections.

Release Profile of Salofalk 750 mg Tablets

This study determined the release profile of Salofalk 750 mg tablets (Axcan Pharma), an enteric-coated 5-aminosalicylic acid (5-ASA) preparation. Twenty-one ileostomates were divided into two groups and studied. Group 1 consisted of 10 subjects (five males, five females, mean age 39 years) who had a mean length of 65 cm of small bowel resected or out of circuit. Group 2 consisted of 11 subjects (eight males, three females, mean age 59 years) whose small bowel was intact. Following an overnight fast and collection of baseline samples, one Salofalk tablet was ingested. Ileostomy effluent and urine were collected for 24 h. Plasma samples were collected hourly for 6 h, then at 8, 12 and 24 h. All subjects ate standardized meals. All samples were stored at --10 degrees C and 5-ASA and N-ac-5-ASA (a metabolite of 5-ASA) were measured by high performance liquid chromatography. The mean intestinal transit time was not statistically different between the groups but the mean ileostomy effluent output was higher in group 1 versus group 2 (10.9 versus 13.1 h, P=0.4; 918 versus 606 mL, P=0.05). The mean peak plasma concentrations of 5-ASA and N-ac-5-ASA were not significantly different (6.12 and 5.42 µ g/ mL, P=0.8, respectively, in group 1 versus 6.75 and 6.66 µ g/mL, P=0.8 in group 2). On average, 33.1% of the ingested dose was recovered in the ileostomy effluent in group 1 versus 21.2% in group 2 (P=0.06) whereas the mean recovery in urine was 40.9% in group 1 but 62.9% in group 2 (P=0.001). These results suggest that 5-ASA is released in the small bowel. There was decreased absorption of 5-ASA and increased recovery of 5-ASA in the ileostomy effluent of subjects who had a small bowel resection.