Clinical involvement of mesenteric and antimesenteric borders of small bowel loops. I. Normal pattern and relationships

Asymmetric mucosal structure, mesenteric versus antimesenteric, in mouse, rat, and human small intestines

The morphology of the small intestinal mucosa is reflected by the degree of stimuli. Previous studies have come to different conclusion about whether the mucosa is equally symmetrical. The aim of the study is to investigate whether there are structural differences in the mesenteric versus antimesenteric mucosa in mice, rats, and humans. Jejunal biopsies from mice and rats were saved. Samples from human small intestine were obtained from patients undergoing Roux-en-Y gastric bypass surgery. Fixed samples were used to morphologically evaluate villus height and enlargement factor due to villi. The number of goblet cells, mast cells, enteroendocrine cells, and Paneth cells were histologically analyzed in the villus structure. Cell turnover was analyzed by Ki-67 staining. There was a significant increased villi height and villus enlargement factor antimesenterically in mice, rats, and human small intestines. The distribution of goblet cells, mast cells, and Paneth cells were equal while the number of enteroendocrine cells was increased antimesenteric in the human samples. The crypt mitotic activity was almost 20% higher in the antimesenteric part of jejunum. In summary we found longer villi, greater surface enlargement, and increased number of enteroendocrine cells as well as increased cell turnover antimesenterically. These differences may be of importance in understanding normal gastrointestinal physiology in health and disease.

Simplified approach to differential diagnosis of small bowel abnormalities

By analyzing the morphology of a focal lesion or the distribution, location, and morphology of the intestinal folds, the radiologist can come to a specific diagnosis or construct a graded differential diagnosis. This article presents a simplified approach to the differential diagnosis of small intestinal diseases by combining this roentgen analysis with the clinical history.

Spread of disease via the subperitoneal space: the small bowel mesentery

The designation of the subperitoneal space emphasizes the continuum of the potential space of extraperitoneal and intraperitoneal areolar tissue traversed by blood vessels, lymphatics, and nerves. Across its root, the subserous connective tissue of the small bowel mesentery is anatomically continuous with that deep to the posterior parietal peritoneum. There is thereby provided an avenue of spread from multiple sites to and from the small bowel mesentery and its relationships. These include perforated lesions of the bowel, pancreatitis, lymphoma, neuroblastoma, leiomyosarcoma of small bowel, and hemorrhage of retroperitoneal and pelvic origin.

Clinical involvement of mesenteric and antimesenteric borders of small bowel loops. II. Radiologic interpretation of pathologic alterations

Many small bowel abnormalities selectively involve the mesenteric or antimesenteric borders of small intestinal loops solely or predominantly. This report documents the roentgen localization and diagnosis of a variety of intraabdominal disease states by their effects specifically on the mesenteric or antimesenteric margins of small bowel loops. The conditions with selective or predominant involvement of either the mesenteric or antimesenteric borders include diverticulosis, Meckel's diverticulum, intestinal duplication, seeded metastases, hematogenous metastases, regional enteritis, lymphoma, and intestinal ischemia and intramural bleeding.