Aim: To investigate the risk indicators, pattern of clinical presentation and treatment strategy of superior mesenteric artery syndrome (SMAS) after scoliosis surgery.
Methods: From July 1997 to October 2003, 640 patients with adolescent scoliosis who had undergone surgical treatment were evaluated prospectively, and among them seven patients suffered from SMAS after operation. Each patient was assigned a percentile for weight and a percentile for height. Values of the 5th, 10th, 25th, 50th, 75th, and 95th percentiles were selected to divide the observations. The sagittal Cobb angle was used to quantify thoracic or thoracolumbar kyphosis. All the seven patients presented with nausea and intermittent vomiting about 5 d after operation. An upper gastrointestinal barium contrast study showed a straight-line cutoff at the third portion of the duodenum representing extrinsic compression by the superior mesenteric artery (SMA).
Results: The value of height in the seven patients with SMAS was above the mean of sex- and age-matched normal population, and the height percentile ranged from 5% to 50%. On the contrary, the value of weight was below the mean of normal population with the weight percentile ranging from 5% to 25%. Among the seven patients, four had a thoracic hyperkyphosis ranging from 55 degrees to 88 degrees (average 72 degrees), two had a thoracolumbar kyphosis of 25 degrees and 32 degrees respectively. The seven patients were treated with fasting, antiemetic medication, and intravenous fluids infusion. Reduction or suspense of traction was adopted in three patients with SMAS during halo-femoral traction after anterior release of scoliosis. All the patients recovered completely with no sequelae. No one required operative intervention with a laparotomy.
Conclusion: Height percentile < 50%, weight percentile < 25%, sagittal kyphosis, heavy and quick halo-femoral traction after spinal anterior release are the potential risk indicators for SMAS in patients undergoing correction surgery for adolescent scoliosis.