gms | German Medical Science

Objective: Spine lesions causing circumferential encroachment of the spinal canal usually necessitate a two-stage approach to achieve 360-degree access and decompression. The purpose of this study was to describe the posteromedian extracavitary approach via a single dorsal midline incision and to assess its effectiveness in the surgical treatment of such lesions.

Methods: In this retrospective study, 10 patients aged 64±10 years underwent a posteromedian extracavitary approach for malignant (n=7) or inflammatory (n=3) lesions of the thoracolumbar spine (T2-L2) in 2004 and 2005. The surgical procedure consisted of a complete laminectomy of the pathologic vertebra(e) and resection of the pedicles to their bases. After isolation and potential ligation of the neurovascular bundle, the transverse process, the rib head and the proximal rib were subperiostally dissected and removed. Without violating the visceral pleura, an extracavitary dissection was performed as necessary to expose the lateral portions and the anterior surface of the vertebral body to achieve partial (n=5) or complete (n=5) vertebrectomy. Reconstruction was achieved by anterior placement of a Harms cage filled with polymethylmethacrylate or autograft and by posterior pedicle screw instrumentation.

Results: Removal of 1.6±0.7 vertebrae was followed by fixation of 3.7±1.1 levels. Duration of surgery amounted to 5.4±1.7 hours. All patients had improvement of neurologic function and 6 of 8 patients, which had been non-ambulatory preoperatively, regained ambulatory function. There was one wound infection and no mortality.

Conclusions: The posteromedian extracavitary approach allows piecemeal or en bloc resection of complex lesions of the thoracolumbar spine. Circumferential exposure and decompression of the spinal cord plus three-column fixation can be safely performed in a single stage operation via a posterior midline incision.