Many surgical procedures are available to help treat metastatic spinal tumors and/or their related symptoms. In general, there are two categories of surgery:
- Minimally invasive surgery involves relatively small incisions and shorter recovery times
- Open surgery is more extensive with larger incisions and a longer recovery period
When surgery for a metastatic tumor is indicated, it is typically one part of a comprehensive treatment program that may also include radiation therapy, medications, and/or chemotherapy.
Minimally Invasive Surgery for Metastatic Spinal Tumors
Surgery is considered minimally invasive when it involves small incisions (such as half an inch or less) and minimal tissue disruption. Most minimally invasive procedures are done on an outpatient basis, meaning that the patient can go home the same day.
This procedure involves inserting a needle through a small incision in the back so that a medical-grade bone cement can be inserted into a fractured vertebra to fill in the empty spaces and act as an internal cast to stabilize the bone. The treatment is designed to reduce pain, prevent further collapse of the vertebra, and restore the patient's mobility.
In addition to injecting bone cement into a vertebra, kyphoplasty has the additional step of first inserting a balloon into the bone and inflating it to create a cavity. This treatment is designed to stop the pain caused by a spinal fracture and to stabilize the bone via an internal cast.
This procedure involves a small incision in the thigh for access to the femoral artery. A catheter guided by a wire is directed through the vascular system to the tumor with the aid of imaging. Once the tumor is located, a chemotherapeutic agent is injected directly into the tumor to shrink or destroy the tumor to remove pressure on individual nerve roots or the spinal cord.
Open Surgery for Spinal Tumors
In general, extensive surgical procedures (open surgery) are typically avoided in patients with metastatic spinal tumors. Patients with metastatic cancer are susceptible to systemic complications, and thus the potential benefits of surgery may not be worth the risks.
As a general rule, open surgical procedures for the treatment of metastatic spine tumors are typically performed on patients who meet the following criteria:
- A life expectancy of more than 3 months1
- Neurological deficits (such as weakness, loss of muscle control from spinal cord compression) and/or significant spinal instability
It is likely that stabilization of the vertebra is necessary after the removal of all or part of the tumor, which can be done at the same time (as part of the same surgery).
Spinal Stabilization Surgery
The goal of this surgery is to stabilize the spine by fusing adjacent vertebrae and reducing any deformity that may have developed. Surgeons typically choose the best stabilization method based on tumor type, extent of bone destruction, general patient condition, and anticipated cancer treatments.
There are various spinal stabilization methods available. While the goal is for adjacent vertebrae to fuse, treatments for the cancer—like chemotherapy—may interfere with the bone healing required to create a fusion. Spinal stability in these cases may rely on solid mechanical fixation from implants such as titanium screws, plates, rods and cages.
Spinal Decompression Surgery
Operative methods to relieve pressure placed on the spinal cord are classified as follows:
- Corpectomy—removal of the body of a vertebra and the discs
- Laminectomy (posterior decompression)—removal of a small part of the bony arches of the spinal canal called the lamina
- Costotransversectomy—removal of a part of a rib along with the transverse process of a vertebra
Various other spinal decompression methods are also available, and sometimes multiple methods are combined in a single surgery. The most suitable method of decompression is selected based on a number of considerations, including the anatomical location of the tumor and general condition of the patient.
A newer procedure for metastatic spinal tumor treatment is called separation surgery. In addition to stabilizing the spine, this surgery focuses on removing enough of the tumor to separate it from the spinal cord. After separation surgery, radiation therapy can be performed on the tumor with less risk to the spinal cord.
Separation surgery is typically followed by stereotactic radiosurgery (low doses of external beam radiation therapy from multiple angles) to further shrink the tumor. When indicated, a combination of separation surgery and radiation therapy enables more of the vertebra to remain intact compared to more traditional spinal decompression surgeries.
Risks of Metastatic Spinal Tumor Surgery
There are potential risks associated with surgery for a metastatic spinal tumor, including:
- Possibility of cancer spreading further
- Spinal cord or spinal nerve damage
- Excessive bleeding
Before deciding on surgery for a metastatic spinal tumor, it is important that the risks, benefits, and alternatives to the procedure are carefully explained. The patient must also have all of his or her questions satisfactorily answered by the surgeon prior to choosing surgery.