Measurement of the Angle Between the Superior Mesenteric Artery and the Aorta: Correlation with Body Mass Index

Raza Sayani,Mohammad Hasan,Ali Janjua,Irfan Nazir,Kumail Khandwala,Mustafa Belal Hafeez Chaudhry

doi:10.11648/j.ijmi.20210902.12

Abstract

Objective: To discover the mean figures of the distance and angle between the superior mesenteric artery (SMA) and the aorta in four standard acknowledged body mass index (BMI) classifications in an ordinary populace and for the two genders, to work with a computed tomography CT based finding of Superior mesenteric artery syndrome (SMAS). Methods: A retrospective cross-sectional study was performed on 338 (157 female, 181 male) patients who were referred for abdominal CT examination. Age, sex, weight and height of all patients were noted, and the BMI was calculated. The distance between the SMA and aorta were measured, as was the angle. Pearson and Spearman correlation coefficients were used to correlate distance and BMI category, angle and BMI category, anteroposterior abdominal distance and SMA angle with aortomesenteric distance. Results: The mean BMI of patients in our study was 27.95 kg/m2 while the mean SMA angle, mean anteroposterior abdominal wall distance and mean aortomesenteric distance was 58.74 degrees, 224.35 cm, and 18.98 cm, respectively. The results showed positive correlation of BMI and anteroposterior abdominal distance with SMA angle and distance. This means if BMI increases, SMA angle and aortomesenteric distance will also increase, and vice versa. This same relationship was also valid for anteroposterior abdominal distance with aortomesenteric angle and distance. Conclusion: Our study helps in stating the values of aortomesenteric distance and angle for different BMI categories that can be used in CT-based diagnosis of SMAS in a South Asian population. The values we found for different BMI categories can be used by radiologists as a reference standard.

Highlights

Superior mesenteric artery syndrome (SMAS) is an uncommon reason for upper gastrointestinal obstruction where the third bit of the duodenum is caught between the aorta and the superior mesenteric artery (SMA)
An aggregate of 338 patients were analysed for our study who presented with different complains among which staging of malignancy (30%) was the commonest, followed by other complaints, mainly abdominal pain, surveillance/followup/re-staging of some malignancy, and abdominal infection
A single patient was diagnosed with SMAS with an SMA angle of 13 degrees

Summary

Introduction

Superior mesenteric artery syndrome (SMAS) is an uncommon reason for upper gastrointestinal obstruction where the third bit of the duodenum is caught between the aorta and the superior mesenteric artery (SMA). Patients experiencing the condition regularly present with concerning weight reduction and epigastric agony because of hindrance of the third piece of duodenum [1]. Cardiac cachexia is one of its significant complexities which is for the most part excluded by numerous caretakers [2]. There has been a positive relationship with pressure of the third piece of the duodenum by the SMA with anatomical or mechanical elements and to intense or ongoing decrease of the retroperitoneal fat [3]. Related mechanical components are for the most part significant weight reduction, for example, anorexia nervosa, malabsorption, or hyper-catabolic states like burns, invasive procedures, critical wounds, or malignancies [2].

Methods

Results

Discussion

Conclusion