Although complications are rare, they can occur. Complications are similar to traditional surgery, which may include death and paralysis. Nerve injury, dysesthesia, complex regional pain syndrome, dural tears, bowel injury, psoas hematoma, epidural hematoma, and segmental instability are complications that may occur and may require additional treatment or surgery to resolve. You may have anomalous nerves in the foramen that can cause increased pain before your original pain subsides. Because we are dealing with a deteriorating spine, the degenerative and aging process cannot be reversed, so one of the goals is to make the degenerative process less painful, but it will never-the-less still progress or accelerate. Your pain, therefore, in severe degeneration, may persist or return to its pre-operative level and in some cases may even worsen. In that case, alternatives such as disc replacement or fusion is still possible.
One unavoidable consequence after any surgery is scar tissue. Although it is minimized in Selective Endoscopic Discectomy™, its presence is variable and may be responsible for residual leg pain. The overall serious complication rate causing permanent residual is less than 1-2%.
The most common side effect that may not be deemed a complication is the feeling of numbness or hypersensitivity (dysesthesia) in your leg after surgery. It can occur immediately after surgery or days and weeks later. Dysesthesia cannot be completely eliminated and its causes are still not completely understood. It is sometimes explained by a nerve that has been numb for a long time from prolonged pressure suddenly becoming decompressed and receiving new blood supply. It is also similar to the "phantom limb" phenomenon experienced by some patients who had a limb amputated. Since one of the goals of surgery is to depopulate and ablate the sensitized nerves in the disc to relieve pain, the process of thermal modulation may cause dysesthesia. The actual cause is still speculative, as it can occur even when neuromonitoring does not demonstrate any irritation of the nerve during surgery. When this occurs, it is almost always temporary, but may need nerve blocks and medication to desensitize the nerves.
When your disc becomes hypersensitive to everyday stresses, this can be due to new nerves and blood vessels growing into your degenerating discs. An inflammatory membrane forms, along with a process called angiogenesis and neurogenesis. Ablation of this inflammatiory membrane is associated with an increased incidence of dysesthesia, but ablation also increases the chance of pain relief. There are also anomalous nerve branches that connect spinal nerves to each other and form in the fat over the annulus. These nerves are called furcal or "forked" nerves, and not usually seen by traditional spine surgeon, but can be visualized endoscopically in the area of the foramen and in the triangular zone where the endoscopic instruments must pass. Removal of some of these tiny nerves that are not part of the normal nerve may not be able to be avoided, and can even be found in the surgical specimen.
Communication is very important. Your decision to have SED™ must be made only after you assure yourself that you are fully informed, and any concerns you have must be brought to your surgeon's attention and discussed in detail to your satisfaction. Because this is a new procedure, non-endoscopic surgeons and endoscopic surgeons not familiar with Dr. Yeung’s technique may give you a different opinion that is based on their own experience or with their familiarity with the literature. Some surgeons unfamiliar with the technique may even argue against it. Any concerns brought up by a second opinion should be brought to Dr. Yeung’s attention so he can communicate with your surgeon if you or he desires. Dr. Yeung believes you should have the freedom to make an informed shared decision about your care. After you have made the decision to have SED™, if you have any problems related to your surgery, it is imperative that you call our office at (602) 944-2900 and notify us about any problems. Most complications can be resolved with proper intervention, but unwarranted delay may jeopardize your surgical result.
Complication Risks in Transforaminal Surgery
There are known complications of all spine surgery. The risks are the same with transforaminal endoscopic decompression surgery. There are other risks not recognized by the traditional surgeons who accept post-op dysesthesia, numbness and motor weakness as unexplained or a known risk of the procedure. These risks include anomalous peripheral sensory and motor nerves, sympathetic nerves and furcal nerves.
These nerves in the foramen and epidural space can be visualized by the endoscope directly or indirectly as demonstrated by these videos. Often they are visualized during or after extraction of disc fragments where the nerves are adherent to the fragment.