Spinal fusion is an invasive surgical procedure performed to provide stability to the spine in the case of degenerative disc disease, nerve impingement and/or vertebral movement (spondylolisthesis). The surgery entails the removal of a disc or portion of a disc and the placement of a bone graft in the disc space that will fuse the vertebrae together. Additional grafts and hardware may be used on the outside of the spinal column for extra stability.
Anterior lumbar interbody fusion (ALIF) is one type of spinal fusion surgery often performed to treat degenerative disc disease in cases where a lot of disc height has been lost. Anterior fusion is performed through an incision in the stomach. There are other approaches that dictate approaching through the back or side, but the anterior approach is favored sometimes for its avoidance of back muscles and spinal nerves.
ALIF is generally not performed on people with spinal instability caused by spondylolisthesis (vertebral fracture and movement) or tall disc spaces. In these cases, a posterior approach may be combined with ALIF to provide additional fusion sites.
Every type of surgery comes with unique risks. Risks that all types of fusion surgeries share are failure of fusion, bleeding, infection and scar tissue.
Anterior fusion carries unique risks due to its approach from the front of the body. One potential complication after surgery is incisional hernia. A hernia is present when part of the lining of the abdominal cavity, called the peritoneum, pushes through a hole or weak part in the connective tissue surrounding abdominal muscles and forms a sac. Incision of the abdomen can cause such a weak spot or hole. A hernia may be visibly protrude and retract when coughing or lifting. If it is painful to the touch or does not retract when pushed inward, surgery will likely be needed to patch the weak spot in the abdomen. Parts of organs can become trapped in the hole as the sac grows and blood supply can become cut off, strangling that part of the organ.
For males seeking fusion of the L5-S1 disc space, retrograde ejaculation is a concern. The anterior approach to this spinal segment puts the surgeon’s tools in close proximity with nerves supplying a valve that directs ejaculate from the body. If the nerve supply is damaged and the valve doesn’t open, the ejaculate will be directed to the bladder. While this does not pose risks to the man’s health or feeling of pleasure, it provides distinct complications with conception. An exact rate of incidence is unknown, but could be 5% or higher, according to Spine.org, for men seeking anterior fusion at the L5-S1 segment.
A minimally-invasive form of ALIF is available that requires a smaller incision and the use of a laparoscope, or camera, that guides the surgeon’s tools. While this procedure generally promises shorter recovery time and less scarring, it also poses a unique risk to the great blood vessels, the vena cava and aorta, that lay over the spine and travel to the lower body. Normal ALIF may cause damage to these vessels at a 1-2% incidence rate; risk increases with laparoscopic anterior fusion as the surgeon has limited view and mobility inside the incision pathway. Interference with these blood vessels is a major concern as it causes excessive bleeding.
When considering surgery, it is always important to weigh the risks against the possible benefits. While most surgeons boast fusion rates of 95% and higher, studies exist that put the rate much lower. A small study with 85 participants found that overall fusion rate was 80%. The study also specified results by level of fusion; rate of failure was much higher (31%) at the L3-L4 level than at the L5-S1 level (16%). These are all factors to consider when deciding whether surgery and what type of surgery is worth the risk for your unique situation. More on the above study can be found at http://www.mendeley.com/research/anterior-lumbar-interbody-fusion/.
A Last Resort
Any type of surgery is a last resort, yet not all spine surgeons are hesitant to prescribe fusions. Fusions are mainly performed to relieve pain from degenerating spinal discs. Have you exhausted all other treatment options for your condition?
Unless you are showing signs of major nerve damage (such as impaired bowel and bladder function), surgery should be a long way off. First, months of physical therapy should be performed to strengthen the core muscles that support the spine. You should be tested for muscle imbalances and postural distortions that could have caused excess pressure on the affected disc. A chiropractor or osteopath should check your spine for misalignment and resolve any if found.
Inversion therapy can be pursued at home to increase disc space, or decompression treatments can be sought from a chiropractor with a decompression machine in his or her office. Decompression treatments may or may not be covered by insurance, but they usually cost around $2,000 total without insurance. This is less than the out-of-pocket cost of spinal surgery for most people with insurance.
When considering various options for back pain treatment, be sure you’re informed of the risks and benefits. Anterior lumbar interbody fusion poses unique risks that should be understood before anything is signed off on.