Skin to origin of mesenteric artery study (STOMA): prospective study of distances between stoma location and proximal superior mesenteric artery

Background: Traditional siting of stomas, in the lower abdomen, has been guided by surgical dogma lacking evidence. In the lower abdomen, the combination of a thick and pendulous abdominal apron, can create a challenging and suboptimal site for a stoma. The anatomical determinant limiting delivery of a stoma to the abdominal skin is the distance of the SMA from the lower border of the pancreas. The aim of this cross-sectional study was to compare the distance between the traditional stoma site, and upper abdominal stoma sites, to both the superior mesenteric artery (SMA) origin and SMA at the inferior border of the pancreas on abdominal computed tomography (CT). Methods: A cross-sectional study at a single academic university hospital of adult patients who underwent abdominal CT in Australia. Results: Two hundred and thirteen patients were included. Stoma sites in the upper abdomen were 57-76 mm shorter to the origin of the SMA and inferior border of the pancreas than those positioned at the traditional stoma site (P < 0.001). The mean panniculus thickness in the upper abdomen was 10 mm thinner than in the lower abdomen and increased with increasing BMI (P < 0.001). The ratio between the distance from the xiphisternum to umbilicus, and the umbilicus to pubic symphysis, was 1.10; this ratio increased with increasing BMI. Conclusion: The distance of the SMA to the skin is always shorter in the upper abdomen compared to the traditional stoma site. Consideration should be given to placing stomas in the upper abdomen, particularly in overweight or obese patients.