Minimal Invasive Spine Surgery (MISS) represents "a paradigm shift" in the surgical management of spinal disorders. Smaller incisions, less tissue dissection, accessing multiple levels through same small incision, low morbidity, faster return to activity and better tolerance elderly population, those with multiple co-morbidities and high risk for anaestehsia, are the benefits of MIS spine surgery.
Dr.Nitin Garg has been using MIS techniques in spine surgery since 2007. Entire spectrum of spinal disorders like cervical and lumbar disc prolapse, spondylolisthesis, trauma, tumors, tuberculosis are treated using this modality.
There are two components of MISS-- decompression and fixation (in some). Decompression requires an access channel to reach the area of interest in the spine. These channels provide direct approach to the surgical site without causing disruption of the normal tissues / muscles. Most of these surgeries are done using tubular ports like Metrx tubes for accessing the pathology. These tubes are of varying diameters from 25mm to 14mm. The advantages of using these tubes is muscle splitting method instead of muscle stripping, accessing two to three levels through the same incision by changing the angulation and bilateral access by one sided approach by "over-the-top" method. In those requiring fixation, this can be achieved using percutaneous transpedicular screws.
Various spinal conditions that are managed using this methods include:
1. Degenerative disc disease :
a. Cervical disc prolapse: anterior cervical microforaminotomy.
b. Lumbar disc prolapse: Endoportal lumbar discectomy for lateral / unilateral discs, percutaneous endoscopic lumbar discectomy for far lateral discs. The patients are discharged the same or next day depending upon their preference.
2. Spondylolisthesis: MIS TLIF -- one and two level fixations are done using enodportal techniques for Grade 1 and Grade 2 sondylolisthesis. In this procedure, bilateral canal decompression can be done from one side by "over-the-top" method. In those with two level listhesis or one level listhesis with adjacent level canal stenosis, both the levels can be accessed using same incision by angulating the tubular port in different directions. Degenerative listhesis is common in elderly who may not tolerate the conventional procedure and have a good recovery using this minimally invasive method.
3. Tuberculosis: Tuberculosis of spine is one of the common conditins encountered by spinal surgeons in our country. Surgery is required in these patients when they develop neurological deficits due to cord compression, deformity, non-resolution of the disease and persistent disabling pain. Dr Nitin Garg has one of the largest series of treating tuberculosis of spine using MIS methods. He has presented his original work at SMISS conference (2012) and published this in Clinical Orthopaedics and Related Research (CORR) in 2014. The procedures include endoportal transpedicular microscopic and endoscopic assisted decompression, transforaminal endoscopic decompression, percutaneous fixations, Direct Lateral Lumbar Intrbody fusion (DLIF). He performed one of the earliest cases of DLIF in lumbar tuberculosis (published in Indian Journal Of Neurosurgery (2014). He has also authored a chapter on Minimally Invasive methods in Tuberculosis of Dorsal and Lumbar spine in "Textbook of Minimally Invasive Spine Surgery".
4. Trauma: This is another widening indication of MIS spinal surgery. Stable burst fractures with no neurological deficits can be fixed by MIS fixation (percutaneous transpedicular screw fixation). This hastens the recovery with minimal surgical morbidity, allows for early mobilisation and acts as an internal splint to avoid further collapse and neurological compromise. Odontoid fractures can be managed by trans-odontoid screw thereby preserving the mobility of the rotation movement at C1-C2 joint.
5. Tumors: Intradural extramedullary tumors as meningioma, neurofibroma, schwanomma are managed using MIS methods. Integrity of spinal elements is maintained while removing the tumors. All such tumors are excised using one level hemilaminectomy approach. Extradural bony tumors as metastatic spine disease, plasmacytoma / multiple myeloma, aneurysmal bone cyst and intramedullary tumors as astrocytomas, ependymomas, abscess require conventional microscopic surgery.
6. Osteoporosis: Osteoporosis is a increasing medical condition which requires appropriate medical management. Surgical intervention is required in those with osteoporotic collapse of the spine. Percutaneous methods as vertebroplasty, kyphoplasty are routinely performed under local anaesthesia. This provides immediate stability to the collapsed vertebrae and also relieves pain. In those with neurological deficit due to significant collapse and retropulsion, corpectomy is done using mini-open thoracotomy followed by cement augmented percutaneous screws fixation in the same sitting. The patient and family is stressed upon that osteoporosis is a chronic and progressive condition and importance is given to concurrent medical management.
MIS spine surgery has significantly improved the ability of the spine surgeons to perform spinal surgeons in medically compromised and elderly patients who may not tolerate extensive conventional surgeries apart from routine patient population.