Symptomatic thoracic disc prolapse is a rare pathology, reported to occur in 1 per million per year,2,3
accounting for 0.15–4% of all symptomatic disc prolapses.1,2
It occurs more commonly in those aged 30–50 years,with a male:female ratio ranging from 1.5:1 to almost equal.1–3
Wood et al
reported 37% of the subjects in their study to have asymptomatic thoracic disc prolapse evident onMRI.
Up to 75% of thoracic disc prolapses occur below T8, with T11/12 being the commonest level.1–3
Disc calcification is common and is reported to occur in up to 65% of case.2
As in our case, calcified discs can fragment with migration of these fragments resulting in compression of the nerve roots.
Pain is the commonest symptom associated with thoracic disc prolapse.1,2
Typical thoracic spinal pain can be unilateral, bilateral or radicular.1,2
Its nature can be variable – sharp, cutting, shooting, constant or intermittent.1,2
Pain can also present as non-spinal pain including abdominal pain, testicular or groin pain, upper limb and cardiac pain.1,5–9
Abnormal neurological symptoms are the second most common presentation.1–3
These include, sensory (para esthesia, dysaesthesia and numbness), motor and bladder or bowel disturbance.1–3
There are few case reports describing abdominal pain, resulting from a thoracic disc prolapse.5–9
These indicate that there is no consistent mode of presentation of the pain in its nature, site or duration. In the case we have described, the site (left iliac fossa) and nature of the pain (intermittent or ‘colicky’) has, to our knowledge, not been previously reported.
As demonstrated in the case, many of these patients undergo unnecessary invasive procedures and surgery for suspected intra-abdominal or pelvic pathology, before a thoracic disc prolapse is diagnosed (e.g.
endoscopic retrograde cholangiopancreatography,8
hysterectomy and salpingio-oopherectomy,5
and Roux-en-Y pancreaticojejunostomy3
MRI is currently considered to be the most informative method of investigation, though plain X-ray and CT scanning or myelography may also be used to aid diagnosis and treatment.3,4,10
The management of thoracic disc prolapse may be determined by the symptoms. Pain without any neurological abnormalities may initially be amenable to nonoperative management, with non-steroidal analgesia and physiotherapy.2,11
Brown et al
reported that over 75% of their case series returned to normal activity with conservative management alone.
In patients with severe intractable pain and neurological symptoms, surgical management is advocated.2,11
Early studies reported the use of laminectomy for excision of thoracic disc to be suboptimal.1–3,8,12
Following these results, alternative safer approaches have been used. These approaches include the posterior and posteriolateral lateral (lateral extracavitary and costotransversectomy) 1,2,10
and the anterior transthoracic (trans- or extrapleural) approaches via thoracotomy or thoracoscopy.1–3,10
Minimally invasive techniques for these approaches are being increasingly employed and actively investigated.2,10
The unilateral interlaminar laminotomy (a variation of the transpedicular approach) was successfully used in the case we have described.12