Micro- Endoscopic Decompression
Overview: This procedure is similar to Posterior Lumbar Decompression/Laminectomy, except that the decompression is done through a ‘key hole’ incision with a series of tubular dilators and a microscope/ endoscope docked over it.
The indications of surgery are generally the same.When the primary pathology affects spinal stability, Fusion and Stabilization is done in the same setting. This can be done through MISS technique known as MIS TLIF.
Surgery is usually suggested as the last resort. Failure of medical management, severe neurological compression causing weakness are usual circumstances when surgery is advised. After a thorough discussion (understanding risks and benefits) with the surgeon, the decision for surgery is taken.
The procedure is done under general anaesthesia. A tube is inserted in the throat to help breathing during anaesthesia. Patient is placed prone (face down) on the operating table. A small 2 cm incision is taken over the lower back after confirming the level under C-arm (Intra operative X-ray). The muscles overlying the spinal are split instead of cutting them. A series of tubular dilators are used to split the muscles. A microscope/ endoscope is docked over the tube. Using high speed burr, the bone overlying the canal is removed on the same side (Laminotomy) as well as the opposite side of approach (Over the Top Decompression). This can be achieved by tilting the operating table and ‘wanding’ the tube which is a distinct advantage of MISS. Any tissue compressing the nerve root is excised and wound is stitched. In cases of Instability, fusion and stabilization is achieved in same setting MISS technique– MIS TLIF. Through ‘key hole’ incisions Percutaneous Pedicle Screw Fixation is done and interbody spacer filled with bone graft is inserted. After the surgery, patient may be shifted to ICU for observation or to the room depending upon the medical condition. Patient is usually made to walk on the same/ next day. Normally, 1-3 days of hospital stay is required. Once medical condition is stabilized, patient has adequate pain relief and mobilized, discharge is planned.
Patient is asked to follow up for stich removal between 2-3 weeks from surgery. A waterproof dressing may be applied in some patients so that bath can be taken. Patient is required to follow up at 6 weeks, 3 months, 6 months, 1 years and then annually after surgery for examination. Based on recovery – gradual increase in activities is advised.
Note: In a few cases, the surgeon may plan to convert the MISS surgery into Laminectomy is he/she feels that’s the best approach to achieve the goals of surgery.
With regards to complications, it has been shown that MISS has less infection rates. Similarly, in cases of Dural Tears, muscles usually fall back and hence, less chances of wound leaks and headaches. The profile of complications remain the same.
Disclaimer: The description of procedure is how usually a surgery is done. During the procedure, based on intra operative encounters which varies from patient to patient different steps may be performed.