Incidence and Potential Risk Factors of Superior Mesenteric Artery Syndrome After Spinal Corrective Surgery in Patients with Adult Spinal Deformity

OBJECTIVE: This study aimed to determine the incidence and potential risk factors of superior mesenteric artery syndrome (SMAS) after corrective spinal surgery in pa-tients with adult spinal deformity (ASD).METHODS: In total, 102 patients (67.6 +/- 8.4 years; 8 male/94 female; body mass index (BMI); 22.4 +/- 3.6 kg/m2) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parame-ters, including thoracolumbar kyphosis (TLK: T10-L2) and -pper lumbar lordosis (ULL: L1-L4) were measured. To evaluate the potential risk factors of SMAS, the angle and the distance between the superior mesenteric artery and aorta, the aortomesenteric angle (AMA) and aortomesen-teric distance (AMD), were evaluated pre-and post-operatively. Based on the postoperative AMA, AMD, and abdominal symptoms, the patients were diagnosed with SMAS. Correlations between demographic data or spinal parameters and AMA and AMD were assessed.RESULTS: Two (2.0%) patients were diagnosed with SMAS. Postoperative TLK significantly correlated with postoperative AMA (P = 0.013, 0.046). Postoperative ULL was significantly correlated with postoperative AMD (b = L0.27; P = 0.014).CONCLUSION: The incidence of SMAS after corrective spinal surgery in patients with ASD was 2.0%. Post-operative smaller TLK and greater ULL can be risk factors for developing SMAS. Spine surgeons should avoid over -correction of the upper lumbar spine in the sagittal plane to prevent SMAS.