The human ileocaecal junction: anatomical evidence of a sphincter.

PURPOSE: The human ileocaecal junction (ICJ) is a major transition zone regulating intestinal transit. Historically, it has often been considered a valve rather than a sphincter. The microscopic anatomy of this junction was studied searching for evidence of an anatomical sphincter and neuromuscular specialisation. METHODS: Ileocaecal specimens were obtained from ten cadavers and five surgical donors (7 male, mean age 81 years, age range 68-94) and examined by histology and immunohistochemistry. Quantitative analyses of muscle thickness and submucosal vascularity were performed together with immunohistochemical studies of innervation and the distribution of interstitial cells of Cajal. RESULTS: The thickness of the muscular layer in both the ileum and the colon increased significantly over a distance of 1 cm leading up to the base of the ileal papilla where it reached a maximum (4.19 ± 2.0 mm) before gradually tapering towards the tip of the papilla. Submucosal vascularity in the ileal papilla was not increased compared to the adjacent ileum or caecum/colon. Neuronal density was less in the caecum and ileal papilla compared to the terminal ileum (P < 0.05). Interstitial cells of Cajal were identified within the myenteric plexus of the ICJ but their density was similar to the adjacent bowel. CONCLUSIONS: A localised muscle thickening at the base of the ileal papilla is consistent with an intrinsic anatomical sphincter. There was no evidence that the ICJ has increased submucosal vascularity or a greater density of innervation compared to the adjacent bowel. The term ileocaecal valve is misleading and should be replaced by ileocaecal junction.

New Zealand Society of Gastroenterology Guidelines for the Management of Refractory Ulcerative Colitis.

The management of patients with ulcerative colitis who are dependent on corticosteroid for control of symptoms, or refractory to corticosteroids or standard immunosuppressive therapy, is challenging. The development of newer medical therapies has increased the options for managing patients in this situation, but access and funding remain limited. This guideline summarises the literature regarding this situation and provides guidance as to the management of refractory colitis in the New Zealand setting.

Use of a monoclonal antibody to sucrase-isomaltase for evaluation of the columnar cuff after stapled restorative proctocolectomy.

PURPOSE: Restorative proctocolectomy with a double-stapled pouch-anal anastomosis retains a cuff of diseased columnar mucosa (columnar cuff) in the upper anal canal that may require biopsy. Biopsying this can be difficult and colonic phenotypic change in the pouch can lead to errors interpreting the histology. This study was designed to investigate the use of a monoclonal antibody to sucrase-isomaltase for differentiating ileal pouch from columnar cuff mucosa. Then, by using this antibody, the ability to accurately take and report biopsies from the anal canal was examined. METHODS: The technique of staining for sucrase-isomaltase was developed. From 113 patients who had a double-stapled pouch-anal anastomosis, 467 formalin-fixed biopsies and 177 fresh-frozen biopsies were taken from the ileal pouch, columnar cuff, or anal transitional zone. Biopsies were stained with a monoclonal antibody to sucrase-isomaltase, and fixed biopsies were routinely reported after staining with hematoxylin and eosin. RESULTS: A monoclonal antibody to sucrase-isomaltase reliably discriminated between ileal from rectal mucosa. A biopsy of columnar cuff mucosa as reported by routine histology was obtained during 72 percent of attempted outpatient examinations. Sucrase-isomaltase staining of reported columnar cuff biopsies showed that biopsies were of pouch rather than columnar cuff in 4.4 percent (95 percent confidence interval, 2-8) of outpatient examinations. CONCLUSIONS: The monoclonal antibody to sucrase-isomaltase used in this study may have a clinical role when interpreting columnar cuff biopsies from patients being investigated for pouch dysfunction, or in patients having surveillance biopsies to exclude neoplasia in the columnar cuff.