Tuesday, July 28, 2015
Is a spinal/epidural anesthetic possible?
I had an L1-L2 fusion some time ago using a bone graft from my hip. It was a long time ago and I haven`t had any problems with it since then. I need to have prostate surgery for BPH (Benign Prostatic Hyperplasia) (Ugh!) and was told that I would need general or a spinal anesthetic. Does my previous spinal surgery preclude a spinal or epidural? The idea of a general anesthetic seems scary. Thanks.
Thanks for the question. Previous spinal surgery does not preclude a spinal or epidural, but it does make the procedure potentially more challenging. This issue does not appear to have been studied systematically. What we know comes from anecdotal reports and case series, most of them examining the issue of epidural anesthesia after spinal surgery. What these reports suggest is a higher chance of failure, with the epidural catheter not finding the epidural space or the needle encountering a blood vessel.
Nevertheless, the fact that epidural anesthesia is possible about 80% of the time suggests that spinal anesthesia is at least as likely to be successful.
After fusion, your spine by definition is not as flexible as a normal spine; its anatomy has been fundamentally altered by the surgery. This makes it difficult for you to adopt the fully flexed posture that gives the anesthesiologist with needle the best access to the fairly narrow "passage" between the vertebrae. It might make it necessary to bring the needle in at more of an angle. An experienced practitioner will know what to do and how to do it with the least chance of hurting you in the process.
The possible result of this technical challenge is a higher incidence of failure, after multiple attempts. Multiple attempts could increase your chances of developing a so-called spinal headache. They might even increase the chances of an accidental neurological injury, although if this was reported more than a handful of times you can be sure that a consensus would have been reached not to ever attempt spinal anesthesia after spinal fusion surgery. Reassuringly, most nerve injuries reported from spinal or epidural anesthesia, while rare, are also transient, with the nerve recovering over days to weeks.
You will not get operated on without anesthesia! So, the consequence of failed spinal anesthesia is that you get a general instead.
The long and short of it is that this is a judgment call to be made by you and your anesthesiologist. You would have to weigh the theoretical increased chance of complications, mainly failure, but maybe nerve injury (probably low), against your preferences for this technique, your anatomy (current X-rays or MRI may help), any current neurological symptoms (sure to scare your anesthesiologist from your spine) and any other medical issues you may have.
Gareth S Kantor, MD
Assistant Professor of Anesthesiology
School of Medicine
Case Western Reserve University