What is Minimally Invasive Scoliosis Surgery and what are the advantages of this approach?
The goal of scoliosis surgery is to both reduce the abnormal curve in the spine and to prevent it from progressing further and getting worse. To achieve this, a spinal fusion is performed to fuse the vertebrae, in the curve to be corrected. This involves placing bone graft or bone graft substitute in the intervertebral space between the two vertebrae. Instrumentation such as rods and screws are also used to realign and stabilize the vertebrae until the graft heals and fuses the two vertebrae together.
There are several approaches to perform scoliosis surgery. Traditional approaches involve making a long incision over the curve to be corrected and cutting and retracting the muscles and tissues over the spine to gain access to the vertebrae that need to be fused. With advancements and innovations in endoscopic and minimally invasive surgical techniques, surgeons can achieve the same goals as open surgery, yet with much less trauma to the surrounding muscles and tissues through minimally invasive scoliosis surgery.
Minimally invasive scoliosis surgery is an endoscopic procedure in which surgery is performed through a few small incisions rather than one long incision. In this approach a thin telescope-like instrument with a tiny video camera called an endoscope is inserted through one of the small incisions. The inserted endoscope provides the surgeon with internal images of the patient’s body onto a television screen in the operating room. These images and intraoperative X-ray images from the fluoroscope positioned around the patient, guide the surgeon to perform the surgery through small incisions. The use of endoscope and fluoroscope also improves visualization of the chest cavity and spinal column and allows greater flexibility for placement of the instrumentation in the spine.
Less invasive surgical techniques such as the use of a series of sequential dilators to dilate the muscles without cutting them and a retractor to create a small tunnel to view the spine are also used, resulting in less trauma to the surrounding muscles and tissue. These provide additional advantages that include:
- Few small scars rather than one large scar
- Less blood loss during surgery
- Less post-operative pain
- Shorter hospital stay
- Reduced risk of infection
- Shorter recovery time with a quicker return to daily activities, including work
Who are the ideal patients for minimally invasive scoliosis surgery?
Minimally invasive scoliosis surgery is not appropriate for every patient. It is usually used when scoliosis curvature lies in the thoracic spine. For thoracolumbar (mid to lower-back) curves and lumbar (lower back) curves, a usually traditional open procedure is preferred. In patients with a double thoracic curve, neuromuscular curves, significant kyphosis (hunching of the spine), or lung problems mostly an open procedure is recommended.
Your doctor will determine the right approach for you depending on the type of scoliosis, location of the curvature of the spine, ease of approach to the area of the curve, and also their preference.
How is minimally invasive scoliosis surgery performed?
For the minimally invasive surgery, you’ll first be administered general anesthesia and put to sleep. You will be then be positioned on a radiolucent operating table, which allows the surgeon to take intraoperative X-rays of your spine with a fluoroscope positioned around you. This guides the surgeon in determining the correct position of the incision and also in instrument placement during the procedure.
- First, a few small incisions are made depending on the location of the spinal curve, the number of levels to be fused and the viewpoints required to clearly visualize the spine for instrument placement.
- A thin membrane that lines the chest cavity is gently cut and pulled away to gain access to the spinal bones. Sometimes, even a portion of the rib is also removed either to serve as a source of bone graft for fusion or to improve the patient’s aesthetic appearance especially with the presence of a prominent rib hump.
- Disc material is removed from between the vertebrae involved in the curve. Removal of the disc material increases the flexibility of the curve and also provides a large surface area for spinal fusion.
- Screws are then fixed to the vertebrae to be corrected, guided by the images from the endoscope and fluoroscope.
- The bony surface between the vertebral bodies is roughened and bone graft or bone graft substitute is packed into the space between the vertebral bodies to promote fusion. The source of bone graft may include the removed rib, the crest of the pelvis, or allograft (donor) bone.
- A specially contoured customized rod is then attached to the fixed screws at each vertebra. The screws are then tightened appropriately to achieve proper correction of the spinal deformity as possible.
- The endoscope and the retractor are pulled out and the incision is closed.