Measurement of the Distance and Angle Between the Aorta and Superior Mesenteric Artery on CT Scan: Values in Indian Population in Different BMI Categories.

The primary intention of the study was to "prove" that the reduced angle and distance between the superior mesenteric artery (SMA) and aorta significantly correlates with reduced body mass index (BMI). This in turn indicates the strong etiological role of this factor for causation of SMA syndrome. (Most literature till date still mentions sudden depletion of fat pad between the vessels as a "proposed predisposing factor"). The superior mesenteric artery syndrome is characterized by the compression of the third segment of the duodenum by the mesentery at superior mesenteric artery level and a resulting duodenal (±gastric) dilatation. The disease is closely related with the depletion of the fat pad between the vessels narrowing the angle and reducing the distance between the vessels. A prospective study of 100 patients (58 males and 42 females) in the age range 15-85 years (mean age 50 years) who had undergone CT scan for various other complaints. CT scan had been performed with routine protocol comprising plain phase followed by arterial and venous phase by measuring the angle between the aorta and superior mesenteric artery, and also BMI was calculated. Mean values for distance and angle were obtained with standard deviation and 95 % confidence intervals. Pearson coefficients were also calculated and results tabulated. A strong positive correlation exists between BMI and the angle between the aorta and SMA. With increment in BMI, the angle also increases so less chance of developing superior mesenteric artery syndrome.