A Muscular Abnormality: An Overlooked Cause of Intestinal Pseudo-Obstruction
Anna Best, Cary Chisholm, Ludvik Donner, Debby Rampisela. Scott & White Memorial Hospital and Texas A&M Health Science Center College of Medicine, Temple, TX
Background: Patients with chronic intestinal pseudo-obstruction can present with numerous types of malformations classically categorized into myopathies, neuropathies or mesenchymopathies, although autoimmune causes have been described as well. Previously described structural muscularis anomalies include the presence of extra muscle layers, segmental absence of the muscularis layer and idiopathic fibrosis.
Design: Six cases of intestinal pseudo-obstruction with muscular abnormalities were identified in our files from 1997-2009. The cases were retrieved from storage, stained with desmin and smooth muscle actin and re-examined for characteristic features.
Results: The patients were five women and one man, with ages ranging from 49-78 years. The patients had a 2.5 month to 5 year history of abdominal discomfort, including abdominal distension, constipation, nausea and vomiting. Each patient was treated surgically with partial small bowel resection. Histologically each case had an area that was characterized by crisscrossing of smooth muscle fibers between the muscularis mucosae and muscularis propria, confirmed by strong staining with desmin and smooth muscle actin. This area was recognized grossly as a 0.2-2.0 cm long constriction in 3/6 (50%) of cases and was associated with ulceration in one case and perforation in another. In contrast to typically poor long-term outcomes in the majority of cases of chronic intestinal pseudo-obstruction, three patients remain without any symptoms of gastrointestinal discomfort 1-11 years after resection. One patient had a single episode of small intestinal obstruction two weeks after resection. One patient had a single episode of constipation, nausea and vomiting four years later and one patient suffers from irritable bowel syndrome.
Conclusions: We describe the first six cases of intestinal pseudo-obstruction due to criss-crossing of smooth muscle fibers between the muscularis mucosae and the muscularis propria. Whether this abnormality is congenital or acquired is unknown.
Monday, March 19, 2012 1:00 PM
Poster Session II # 104, Monday Afternoon