There is a major risk that is unique to the ALIF approach. The procedure is performed in close proximity to the large blood vessels that go to the legs .
Damage to these large blood vessels may result in excessive blood loss. Quoted rates in the medical literature put this risk at 1% to 15%, although this should be an uncommon complication in the hands of experienced vascular and spine surgeons.
Retrograde Ejaculation after ALIF Surgery
For males, another risk unique to this approach is that approaching the L5-S1 (lumbar segment 5 and sacral segment 1) disc space from the front has a risk of creating a condition known as retrograde ejaculation.
There are very small nerves directly over the disc interspace that control a valve that causes the ejaculate to be expelled outward during intercourse. By dissecting over the disc space, the nerves can stop working, and without this coordinating innervation to the valve, the ejaculate takes the path of least resistance, which is up into the bladder.
With retrograde ejaculation, the sensation of ejaculating is largely the same, but it makes conception very difficult (special harvesting techniques can be utilized). Fortunately, retrograde ejaculation happens in less than 1% of cases and tends to resolve over time (a few months to a year). This complication does not result in impotence as these nerves do not control erection.
Other ALIF Considerations
In general, the principal risk of this type of spine surgery is that a solid fusion will not be obtained (nonunion) and further surgery to re-fuse the spine may be necessary. Fusion rates for an ALIF should be as high as 90-95%.
Non-union rates are higher for patients who:
- Have had prior lower back surgery
- Smoke or are obese
- Have multiple level fusion surgery
- Have been treated with radiation for cancer.
Not all patients who have a nonunion will need to have another fusion procedure. As long as the joint is stable, and the patient's symptoms are better, more back surgery is not necessary.
Other than non-union, the risks of a spinal fusion surgery include infection or bleeding. These complications are fairly uncommon (approximately 1% to 3% occurrence).
In addition, there is a risk of achieving a successful fusion, but the patient's pain does not subside. For more information, see Failed Back Surgery Syndrome.