Low body mass index: a risk factor for superior mesenteric artery syndrome in adolescents undergoing spinal fusion for scoliosis.

STUDY DESIGN: Five cases of superior mesenteric artery (SMA) syndrome occurred at our institution over a 4-year period in adolescents undergoing spinal fusion surgery for scoliosis. All patients had in common a very slender body habitus. The measurement of body mass index (BMI) was low in all patients and an age-matched control group of patients undergoing similar surgery without this complication was assessed with this Index to determine its utility as a screening tool for this postoperative condition.

OBJECTIVE: The goal was to determine if BMI is a useful parameter to assess the relative risk of patients undergoing spinal fusion surgery for developing the complication of SMA syndrome.

BACKGROUND DATA: SMA syndrome is a serious and potentially fatal complication of spinal fusion surgery for scoliosis. Significant curve correction and slender body habitus have been cited in the literature as potential risk factors for this disorder.

METHODS: BMI and the amount of scoliosis curve correction in the 5 patients developing SMA syndrome after spinal fusion were calculated and compared with those values in a group of 18 age-matched patients undergoing spinal fusion during the same time period.

RESULTS: Absolute curve correction was comparable between the 2 groups. All 5 patients who developed SMA syndrome had a BMI of less than 18.

CONCLUSIONS: Patients undergoing spinal fusion surgery for scoliosis with a BMI of less than 18 are at risk to develop SMA syndrome postoperatively.