Patients in need of surgery for severe, chronic back pain can benefit by today’s modern surgical techniques, especially minimally invasive surgery (MIS) for spinal fusion. Many studies have been done comparing different methods, techniques, and approaches. Given your situation and specific question, there is a recent study published that you might find of special interest.
In this study from the Rothman Institute Department of Orthopaedic Surgery (Thomas Jefferson University), two groups of patients having spinal fusion were compared. All 162 patients had an anterior lumbar interbody fusion (ALIF) first and then a second procedure. The second procedure was a posterior fusion with either an open incision (group one) or a minimally invasive approach (group two). Some patients (but not all) had a decompression of the nerve tissue as part of the second procedure.
A little information about the advantages of the minimally invasive surgery (MIS) gives a greater appreciation for why this approach is being studied so closely. The traditional open incision involves cutting through the many layers of spinal muscles and other soft tissue structures to gain access to the vertebral bones.
With MIS, a tube-shaped instrument is passed down through the soft tissues between muscle groups. The soft tissue structures are pushed aside without cutting them. This technique reduces the risk instability from damage to muscles, tendons, ligaments, and bone. MIS also makes it possible for patients to get up and moving again sooner, allowing for faster recovery.
Fiber optic lighting and advanced imaging technology aid the surgeon in seeing inside the body to perform the necessary steps. After removal of the disc from an anterior (front of the body/spine), bone graft was placed inside the disc space to maintain normal disc height. Then the patients were turned over and operated on from the back. This was when the spinal fusion was done using either the open or minimally invasive approach.
Results were compared using a variety of measures including amount of blood lost during surgery (and need for blood transfusion), length of surgery and minutes of time exposed to fluoroscopy, length of hospital stay after surgery, and complications (type and severity).
As it turns out, blood loss and the corresponding transfusion rates were greater in the open group. But a second look at this difference showed that it was the patients who had an additional surgical procedure (neural decompression) who experienced these complications. And as expected, the MIS group was exposed to longer periods of radiation exposure due to the increased need for fluoroscopy during the procedure.
The unique aspect of this study was the fact that patients had an open anterior spinal fusion followed by a posterior spinal fusion (either by open or a minimally invasive approach). It sounds like this is the type of surgery your surgeon has proposed for you.
The authors of this study concluded that minimally invasive posterior fusion following open anterior spinal fusion does have the advantages of less blood loss and therefore less need for a blood transfusion. MIS was also associated with a shorter hospital stay (and lower costs). Blood loss was greater in the patients who had open neural decompression.
However, rates of major complications such as blood clots, infection, or need for revision surgery due to problems with hardware were similar between the open and MIS group. The benefit or value of a minimally invasive procedure when performing a posterior spinal fusion with decompression may be compromised. And with the increased exposure to radiation required by the added decompression procedure, it may be that the open incision approach is best when decompression is needed.
Your surgeon will be evaluating your case carefully and making decisions based on many personal factors (e.g., your age, size, general health, presence of other medical problems, smoking/tobacco use history, number of spinal levels being fused, diagnostic reason(s) for this surgery) and so on. If it has not been explained to you why the procedure will be done as described, you may want to ask your surgeon for a more in-depth explanation of what will be done and why.