Surgical Outcome of Bilateral Spinal Decompression through Unilateral Laminotomy for Lumbar Canal Stenosis associated with Long-Term Hemodialysis

Patients undergoing long-term hemodialysis often develop spinal canal stenosis caused by β2-microglobulin amyloid deposition in the synovial joints, the intervertebral discs and the ligamentum flavum. Minimally invasive surgery is essential to treat these patients because of their poor general condition and spinal fragility. Bilateral spinal decompression through unilateral laminotomy is one of the minimally invasive surgical techniques for lumbar canal stenosis. This surgical method can accomplish bilateral nerve root decompression without injury of supra- / inter-spinous ligament complex or contralateral paraspinal muscles. In the present study, lumbar canal stenosis of the seven patients undergoing long-term hemodialysis was treated by this technique, and the surgical outcome was evaluated using the Japanese Orthopedic Association score (JOA score) excluding the assessment of urinary function (highest possible score, 29 points). The JOA score ranged preoperatively from 4 to 22 points (mean, 10.9 points), and was improved postoperatively ranging form 16 to 25 points (mean, 20.7 points). The increase in points was equivalent to that of non-dialyzed patients receiving the same operation for lumbar canal stenosis: preoperative scores ranged from 13 to 21 points (mean, 16.7 points), and postoperative scores ranged from 24 to 29 points (mean, 26.7 points). Patients could walk and start rehabilitation training on the next day after their operation, and the postoperative hospital stay ranged from 17 to 39 days (mean, 25.7 days). The technique of bilateral spinal decompression through unilateral laminotomy provides a less invasive operation with an excellent outcome for lumber canal stenosis associated with long-term hemodialysis.