Transpedicular approach for thoracic disc herniation

Thoracic disc herniation is rare in the clinic, accounting for about 0.5% of disc herniation. Disc herniation can occur in any intervertebral space of the thoracic vertebrae, but in the literature statistics, the following thoracic vertebrae are more common. The disease is generally divided into three clinical types: central type, paracentral type and lateral type. Lateral patients are often misdiagnosed as intercostal neuralgia and chest and abdomen pain due to clinical manifestations, making many patients difficult to diagnose. Central and paracentral compression of the thoracic spinal cord produces paraplegia and hemi-lateral lesions of the spinal cord, which is easily diagnosed by myelography, especially MRI. There are many surgical methods for this disease. The lateral type compresses the nerve root, and the surgical method can be performed by using the posterior laminar keyhole windowing method. In the central and paracentral cases of compression of the spinal cord, before the 1950s, laminectomy and decompression were mostly used. Because the prominent intervertebral disc was not removed, the decompression effect was not satisfactory. After the 1960s, some authors used a posterior incision, which was inserted through the anterior lateral, lateral or posterior lateral wall of the thoracic spinal canal. The direct removal of the prominent disc tissue in front of the thoracic spinal cord was significantly improved, but due to the attachment of the thoracic spine, such as lamina, Transverse processes, articular processes and pedicles are more resected, which affects the stability of the thoracic spine. Treatment of diseases: thoracic disc herniation Indication The central and paracentral type of thoracic disc herniation, the symptoms of spinal cord compression are obvious, confirmed by myelography or MRI, early surgery should be performed. Contraindications 1. Complete paraplegia with a course of more than half a year. 2. The lateral type is more invasive through the pedicle approach, and the method of opening the window through the lamina should be selected. Preoperative preparation 1. General general preparation: According to the condition and examination, actively improve the general condition of the patient, and give all necessary supplements and corrections. 2. Those with constipation, laxatives were given before surgery, and enema was given on the night before surgery. Those with dysuria should be catheterized before surgery and indwelling catheter. 3. If you need a prone position after surgery, you should perform prone position training in advance so that the patient can adapt to this position. 4. A sedative was given before the operation, and phenobarbital 0.1 g. 5. Fasting within 6-8 hours before surgery. 6. Prepare the surgical skin before surgery and clean the shaving. The range should be more than 15cm around the incision. 7. Give medication before anesthesia according to the needs of anesthesia. 8. Preoperative positioning: The position of the spine scheduled to be resected should be determined before surgery. The easiest way is to locate according to the body surface markers. Due to the difference in body shape, there may be 1 or 2 spinous process errors by marker positioning. In order to avoid the error, it can be positioned according to the body surface marker, and then a type of lead is glued on the body surface of the corresponding spinous process. After taking the X-ray film, the surgical site is verified from the position of the lead on the X-ray film. Surgical procedure Anesthesia and position Intratracheal intubation was general anesthesia. Take the side of the healthy side, a soft pillow under the waist. Surgical procedure Surgical incision The back is 4 to 6 cm from the midline and 8 to 10 cm perpendicular to the midline. The paravertebral muscles are peeled inward and retracted. 2. Prominent disc positioning The determination of the position of the lower thoracic disc in the lower part is determined by the operator using the finger to find the 12 ribs and collating with the preoperative thoracic X-ray film to accurately determine the intervertebral space. The middle and upper intervertebral discs of the thoracic spine are protruded into the interspinous ligament of the estimated plane with an injection needle, and the lateral radiograph of the thoracic vertebra can also be determined. 3. Pedicle resection Count the transverse process and pedicle of the next thoracic vertebrae of the diseased intervertebral space, remove the soft tissue, remove the transverse process tip with a rongeur, and find the intercostal nerve under the same plane rib head into the intervertebral foramen. The lower edge of the rib head is cut with a micro drill. The pedicle is removed with a micro drill or osteotome, or only the upper half of the pedicle is removed, revealing the lateral portion of the dural sac. 4. Exposing the disc herniation After revealing the lateral edge of the dural sac, continue to find the nerve root cuff and the intercostal nerve connected to it. The disc herniation can be found in front of the dural sac, and the dural sac is usually squeezed back to form a pressure trace. 5. Excision of the herniated disc At this time, it is best to operate under the operating microscope, gently retract the dural sac, and do not pull too much force, so as not to aggravate the symptoms of the spinal cord. Incision of the anterior annulus fibrosus and posterior longitudinal ligament, it is easier to remove the soft nucleus pulposus tissue in the intervertebral space, but it is quite difficult to remove the rigid disc herniation or epiphysis, and the intercostal nerve can be cut off if necessary. The microscopic or osteotome is used to remove the base of the bony prominence, so that the epiphysis collapses and then gradually cut out, and strive to completely remove the compression, completely relieve the compression of the spinal cord. 6. Suture incision This method removes less bone in the thoracic vertebrae and does not require bone graft fusion. Muscle, deep fascia, subcutaneous tissue and skin are sutured layer by layer. complication Postoperative numbness of the lower extremities, unable to increase, due to long-term traction of the dural sac during surgery, mostly temporary.