Circumferential Decompression via a ModifiedCostotransversectomy Approach for the Treatment of Single Level Hard Herniated Disc between T10 -L1.

To describe a novel surgical strategy for circumferentially decompressing the T10 -L1 spinal canal when impinged upon by single level hard thoracic herniated disc (HTHD) via a modified costotransversectomy approach.This is a retrospective review of 26 patients (17 men, 9 women; mean age at surgery 48.5 years, range 20-77 years) who had undergone single level HTHD between T10 -L1 by circumferential decompression via a modified costotransversectomy approach. The characteristics of the approach are using a posterior midline covered incision, which keeps the paraspinal muscle intact and ensures direct visualization of circumferential spinal cord decompression of single level HTHD between T10 -L1 .The average operative time was 208 ± 36 min (range, 154-300 min), mean blood loss 789 ± 361 mL (range, 300-2000 mL), mean preoperative and postoperative mJOA scores 5.2 ± 1.5 and 9.0 ± 1.3, respectively (t = 19.7, P < 0.05). The rate of recovery of neurological function ranged from 33.3% to 100%. The ASIA grade improved in 24 patients (92.3%) and stabilized (no grade change) in two (7.7%). MRI indicated that the cross-sectional area of the dural sac at the level of maximum compression increased from 45.0 ± 5.8 mm(2) preoperatively to 113.5 ± 6.1 mm(2) postoperatively (t = 68.2, P < 0.05). Anterior tibialis muscle strength of the 15 patients with foot drop had a mean recovery rate of 95% at final follow-up. One patient who resumed work early after the surgery showed a significantly augmented Cobb angle. One patient had transient postoperative cerebrospinal fluid leakage. No patients showed neurological deterioration.This procedure achieves sufficient direct visualization for circumferential decompression of the spinal cord via a posterior midline covered costotransversectomy approach with friendly bleeding control and without muscle sacrifice. It is a reasonable alternative treatment option for thoracic myelopathy caused by single level HTHD between T10 -L1 .