ABOUT
Though minimally invasive spine surgery was first performed in the 1980s, it has recently seen rapid advances. Traditional, open back surgeries can potentially damage normal uninvolved musculature. There are potential chances for damage to normal tissues during the muscle dissection and retraction required to expose the spine, the need for blood vessel cauterization, and the necessity of bone removal. Disrupting natural spinal anatomy is necessary to facilitate decompression of pinched nerves and the placement of screws and devices to stabilize the spine. This may lead to lengthy hospital stays, longer recovery periods, more operative blood loss, and risk of tissue infection.
Minimally Invasive Surgery (MIS) was developed to treat disorders of the spine with less disruption to the muscles. This can result in quicker recovery, decrease operative blood loss, and speed patient return to normal function. Not all patients are appropriate candidates for MIS procedures. It is important to keep in mind that there needs to be a certainty that the same or better results can be achieved through MIS techniques as compared to open procedure.
Many MIS procedures can be performed on an outpatient basis. In some cases, the surgeon may require a hospital stay, typically between 24 hours to 2 days, depending on the procedure.
TYPES OF SURGERIES
There are many types of MIS Surgeries that are performed
Also known as mini-open TLIF, this is an MIS technique that is performed in patients with refractory mechanical low back and radicular pain associated with spondylolisthesis, degenerative disc disease, and recurrent disc herniation. The TLIF approach may also have potential in patients with low back pain caused by postlaminectomy instability, spinal trauma, or for treating pseudoarthrosis. This procedure is contraindicated in patients who have a conjoined nerve root within the foramen, a very rare occurrence, but one that may present during surgery. The major difference in the TLIF approach is that the operation is performed unilaterally, and the bone graft is inserted into the disc space through the side.
Using x-ray guidance, a 2- to 4-cm incision is made approximately 4 to 5 cm lateral to the midline. The muscles are gradually dilated and a tubular retractor inserted to allow access to the affected area of the lumbar spine. The lamina is removed to allow visualization of the nerve roots, and the facet joints may be trimmed or removed to allow more room for the nerve roots. The disc material is removed from the spine and replaced with a bone graft and structural support from a cage made of bone, titanium, carbon-fibre, or a polymer, followed by rod and screw placement. Surgeons may position small screws on the other side of the spine through a percutaneous technique to provide additional stability. The tubular retractor is removed, allowing the dilated muscles to come back together, and the incision is closed.
Microdiscectomy also called micro lumbar discectomy (MLD), is a very common MIS decompression procedure performed in patients with an asymptomatic lumbar herniated disc. The operation consists of removing the portion of the intervertebral disc that is herniated and compressing a spinal nerve root. The procedure is performed from the back (posterior) with the patient on his or her stomach.
A 1- to 2-cm longitudinal incision is made in the midline of the lower back, directly over the area of the herniated disc. Special retractors and an operating microscope are used to visualize the region of the spine, with minimal or no cutting of the adjacent muscles and soft tissues. After the retractor is in place, an x-ray is used to confirm that the appropriate disc is identified. A small amount of bone of the superior lamina may be removed first to expose the disc herniation. The nerve root and neurologic structures are protected and carefully retracted so that the herniated disc can be removed. Surrounding areas are checked to ensure that no additional disc fragments are remaining.
This is an MIS decompression procedure that enlarges the space in which a spinal nerve root exits the cervical spinal canal (intervertebral foramen). This narrowing can be caused by a herniated disc, bone spurs, thickened ligaments or joints, which may result in painful pinched nerves. The procedure is performed from the back (posterior) with the patient on his or her stomach.
A 1- to 2-cm incision is made on the symptomatic side of the neck. Using an operating microscope and x-ray guidance, the muscles are gradually dilated and a tubular retractor inserted to allow access to the cervical spine. Bone or disc material and/or thickened ligaments are then removed to decompress and relieve pressure on the spinal cord and/or nerves. The tubular retractor is removed, allowing the dilated muscles to come back together, and the incision is closed.
Vertebroplasty for the treatment of vertebral compression fractures (VCFs) was introduced in the United States in the early 1990s. The procedure is usually done on an outpatient basis, although some patients stay in the hospital overnight. The procedure may be performed with a local anaesthetic and intravenous sedation or general anaesthesia. Using x-ray guidance, a small needle containing specially formulated acrylic bone cement is injected into the collapsed vertebra. The cement hardens within minutes, strengthening and stabilizing the fractured vertebra. Most experts believe that pain relief is achieved through mechanical support and stability provided by the bone cement. Kyphoplasty involves an added procedure performed before the cement is injected into the vertebra. First, two small incisions are made and a probe is placed into the vertebral space where the fracture is located. The bone is drilled and one balloon (called a bone tamp) is inserted on each side. The two balloons are then inflated with contrast medium (which are visualized using image guidance x-rays) until they expand to the desired height and removed. The spaces created by the balloons are then filled with the cement. Kyphoplasty has the added benefit of restoring height to the spine.