**Abstract**

Myelopathy can result from a thoracic disc herniation (TDH) compressing the anterior spinal cord. Disc calcification and difficulty in accessing the anterior spinal cord pose an operative challenge. A mini-open lateral approach to directly decompress the anterior spinal cord can be performed with or without concomitant interbody fusion depending on pre-existing or iatrogenic spinal instability. Experience using stand-alone expandable spacers to achieve interbody fusion in this setting is limited. Technical advantages, risks and limitations of this technique are discussed. We conducted a retrospective chart review of all patients with thoracic and upper lumbar myelopathy treated with a lateral mini-open lateral approach. Review of the literature identified 6 other case series using similar lateral minimally invasive approaches to treat thoracic or upper lumbar disc herniation showing efficient and safe thoracic disc decompression procedure for myelopathy. This technique can be combined with interbody arthrodesis when instability is suspected.

**Keywords:** Expandable, interbody, lateral, minimally invasive, thoracic myelopathy

## **1. Introduction**

Rapidly progressing myelopathy can result from a thoracic or upper lumbar disc herniation compressing the anterior spinal cord. With a prevalence of approximately 6.5%, thoracic disc herniation (TDH) is not routinely diagnosed [1]. This low incidence contributes to the lack of familiarity with treatment methods and several factors contribute to a reticence for treating TDH. The calcified or ossified nature of the pathology, the difficulty to safely access and decompress the anterior spinal cord without causing worsening myelopathy and the complications associated with thoracic or thoracolumbar spinal approaches make this condition challenging for the spine surgeon.

The anterior thoracotomy approach has been traditionally considered as a treatment of choice to treat thoracic disc pathology. Compared to the posterior

## *Minimally Invasive Spine Surgery - Advances and Innovations*

approaches, such as the costotransversectomy, anterior approaches can offer increased visualization and access to safely decompress midline thoracic lesions. To minimize pain and pulmonary complications associated with thoracotomy, thoracoscopic [2] and more recently the lateral mini-open technique have been reported to treat thoracic disc pathology [3–9]. Although considered a lateral approach, this technique offer direct access to the anterior spinal canal without requiring retraction of the dural sac. Another significant advantage of the lateral mini-open approach is it can be performed without depending on a thoracic access surgeon.

### **Figure 1.**

*The lateral decubitus position was used for the thoracic mini-open lateral approach in a patient with T10–11 myelopathy. Note that the tape used to secure the upper body should be positioned closer to the shoulders in the case of a more rostral thoracic spinal level.*

*Minimally Invasive Lateral Approach for Anterior Spinal Cord Decompression in Thoracic… DOI: http://dx.doi.org/10.5772/intechopen.97669*
