THORACIC DISC HERNIATION

Abstract

Introduction Symptomatic Thoracic disc prolapse (TDH) is a rare condition, with approximately 1 case per million population presenting per year. There are not many Spinal surgeons with a significant experience in the management of these lesions which necessitate a familiarity with the anatomy of the thorax and thoracic spinal cord. TDH is often diagnosed on modern imaging, but the indications for surgery in asymptomatic cases or in patients with spinal pain only, remain undefined. The natural history of TDH is not known and there is a poor correlation between the radiological and clinical presentation. The advent of newer minimally invasive endoscopic techniques for TDH may have reduced the incidence of open procedures for this condition, but may lead to an increase in operations performed for TDH, especially in cases where the surgical indications remain uncertain. In a small country like New Zealand it is especially difficult to build up a large series and to become very familiar with what remains a difficult operation

Methods The Neurosurgical experience with this condition in Auckland over the last ten years was reviewed. Clinical presentation, diagnostic imaging, surgical management and patient outcome were analyzed.

Results Twenty-one patients were treated over the last 10 years. All had symptomatic TDH. Most operations were performed by the senior author. Patient age varied between 30 and 80, with mean age 50.8 years. There was a slight female preponderance (n=14). Most patients were of European ethnicity. Most patients had spinal cord or nerve root dysfunction, but local pain and sensation change were also noted. MRI was the mainstay in diagnosis, and CT scan was often also used. Surgical exposure was aimed at avoiding spinal cord manipulation and will be discussed. The surgical approach was via thoracotomy in most cases, costotransversectomy, pediculectomy and laminectomy. One case was treated conservatively. There was one case of postoperative paraplegia which will be discussed. There were no other permanent major neurological complications. Patient outcomes will be discussed in detail. Patients with motor weakness showed post operative improvement or full recovery. Pain and sensory loss symptoms were less likely to resolve. Complications that warrant discussion included temporary cranial nerve palsy, thoracic empyema, and long-term opioid addiction for pain.

Discussion Over the past 10 years, a reasonable number of patients with TDH have been treated surgically without major incident. The surgical management of this condition remains a challenge. Younger spinal surgeons may not have the training to deal with these cases, which should be addressed. Endoscopic treatment has a steep learning curve, and may not be well suited to larger symptomatic TDH.