The human spine provides support to the body allowing you to stand upright, bend, and twist. The spine can be broadly divided into cervical, thoracic and lumbar spine. Thoracic spine lies in the mid back region between the neck and lower back and is protected by the rib cage.
24 spinal bones called vertebrae are stacked on top of one another to form a spinal column. Between two vertebrae there is a disc of cartilaginous tissue called intervertebral disc. Intervertebral disc acts as a shock absorber and protects the spine from the strong forces of movement during activities such as jumping, running and lifting.
Wear and tear can occur in the disc with age and may cause the soft spongy tissue in the centre of the disc to squeeze (herniate) from a tear on the side of the disc. Disc herniation may also occur due to an injury such as during a car accident or a fall; a sudden and forceful twist of the mid-back or disease of the thoracic spine such as Scheuermann's disease.
The herniated disc protrudes into the hollow tube of the spinal column called the spinal canal and directly pushes against the spinal cord passing through the spinal column. This can injure the spinal cord. Herniated discs can also block blood flow from the one and only blood vessel going to the front of the spinal cord in the thoracic region of the spine, causing nerve tissues in the spinal cord to die.
Symptoms of thoracic disc herniation vary depending on the position and size of the disc herniation, nerve irritation or nerve injury, and damage to the spinal cord. Symptoms may include mid-back pain, pain around the front of the chest that may mimic heart problems, groin pain or pain, numbness and weakness in the legs and arms. It may even affect bowel and bladder function.
Usually thoracic disc herniation is treated conservatively with rest, back brace, medication and physical therapy. Surgery is considered when long term conservative treatment does not relieve pain or the condition is rapidly getting worse or is affecting the spinal cord.
The goal of the surgery is to remove all or part of the herniated disc pressing on the nerve root or spinal cord and is called discectomy. Thoracic discectomy can be performed either through the anterior approach (front side) or posterolateral approach (behind and to the side).
Anterior approach: This approach usually involves open thoracotomy in which the herniated disc is accessed through the chest cavity. An alternative to open thoracotomy is Video Assisted Thoracic Surgery (VATS). VATS is a minimally invasive surgery that is done through several small incisions and involves the use of a thoracoscope, a surgical tool with a tiny camera. Thoracoscope is inserted into the side of the thorax through a small incision to provide real images of the surgical area on a TV screen. These images guide the surgeon to remove the herniated disc using instruments inserted through other small incisions. VATS is minimally invasive and results in quicker recovery than open thoracotomy.
Posterolateral approach: This approach is also called as costotransversectomy. The herniated disc is accessed through an incision on the back of the spine. A window through the bones that cover the herniated disc is created by removing a small part of rib where it connects to the spine (costo means rib) and transverse process (a small bone attached to the spine). The discectomy is then performed with the small instruments.