Association between underweight status or low body mass index and the risk of developing superior mesenteric artery syndrome following scoliosis corrective surgery in pediatric patients: a review of the literature.

Superior mesenteric artery (SMA) syndrome is the compression of the third portion of the duodenum between the abdominal aorta and the superior mesenteric artery. Although multifactorial, the most frequent cause of SMA syndrome is significant weight loss and cachexia often induced by catabolic stress. SMA syndrome resulting from scoliosis surgery is caused by a reduction of the aortomesenteric angle and distance. Risk factors include rapid weight loss, malnutrition, and a rapid reduction in the mesenteric fat pad and are the most common causes of a decrease in the aortomesenteric angle and distance. Surgically lengthening the vertebral column can also lead to a reduction of the aortomesenteric distance, therefore, has been identified as a risk factor unique to spinal surgery. Despite a reported decline in SMA syndrome cases due to improved surgical techniques, duodenal compression is still a risk and remains a life-threatening complication of scoliosis surgery. This article is a cumulative review of the evidence of being underweight or having a low body mass index as risk factors for developing SMA syndrome following surgical scoliosis instrumentation and correction.