Transpedicular Approach for Thoracic Disc Herniations

Mark H. Bilsky, M.D., Division of Neurosurgery, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York

Neurosurg Focus. 2000;9(4) 

In This Article

Abstract and Introduction

Object. Patients with symptomatic herniated thoracic discs may require operation for intractable radiculopathy or functionally disabling myelopathy. In the past, laminectomy was the procedure of choice for the treatment of thoracic herniations, but it was found that the approach was associated with an unacceptably high rate of neurological morbidity. Several strategies have been developed to excise the disc without manipulating the spinal cord. The focus of this paper is the transpedicular approach.
Methods. The author retrospectively reviewed the cases of 20 consecutive patients presenting with herniated thoracic discs in whom surgery was performed via a transpedicular approach. Fourteen patients presented with acute myelopathy and six with radiculopathy. Of those with myelopathy six of six regained ambulation and six of seven regained normal bladder function. No patient with myelopathy experienced neurological worsening. In four patients presenting with radiculopathy postoperative pain resolved, and in two it remained unchanged. Three minor complications (15%) occurred. No patient suffered postoperative spinal instability-related pain or delayed kyphosis.
Conclusions. As experience accumulates in the use of multiple approaches for the treatment of thoracic disc herniations, the role of each is becoming more clearly defined. The transpedicular approach is most applicable to lateral or centrolateral calcified or soft discs. The more anterior (transthoracic or thoracoscopic) and lateral (costotransversectomy or lateral extracavitary) approaches may be more useful for excision of central calcified discs.

Herniated thoracic discs are relatively common but rarely require operation. Based on large studies examining radiographic and postmortem studies, the incidence of asymptomatic thoracic disc herniations is 10 to 37%.[3,7,31,32,38,44,46] Despite the high prevalence of thoracic disc herniations in the general population, they are rarely symptomatic, and of all operations for disc herniations only 2% are performed in the thoracic spine.

In the 1950s, laminectomy was performed to excise herniated thoracic discs; however, it resulted in greater than 70% of patients suffering significant postoperative deficits, the majority of whom became paralyzed.[2,8,11,18,21,25,28,30] Multiple operative approaches have been developed to treat thoracic disc herniations to overcome the significant neurological morbidity associated with a strictly posterior laminectomy. These approaches are currently categorized as anterior (transthoracic,[5,6,12,15,22,29,34,35,39,41,43] transsternal, and thoracoscopic[10,19,20]), lateral (lateral extracavitary[13,14,16,41,43] and costotransversectomy[1,6,15,31,37,40]), and posterolateral (transpedicular[4,15,17,23,24,33,36,40] and transfacet pedicle sparing[41,42] ). The authors of numerous surgical series have demonstrated significantly improved neurological outcomes, pain relief, and postoperative spinal stability with these varied approaches compared with laminectomy. Since Patterson and Arbit [33] first described the transpedicular approach in 1978, we have used this technique to excise all thoracic disc herniations until recently. Whereas the transpedicular approach is associated with a lower rate of morbidity than the anterior and lateral approaches, these other approaches may be more effective for central calcified discs.[41,43]