If at first you don’t succeed, try again!
We wanted to share a perfect example of one of the challenges and occasional frustrations of peripheral nerve surgery in the world of chronic pain, which does keep many good physicians out of this field. This is also an example of why at times peripheral nerve surgery sometimes “does not seem to work.” However, this story has a GREAT ending, and it a good example of -- if you first don’t succeed, perhaps it is best not to give up too easily.
We recently had the privilege of caring for a delightful young lady with a long history of right thigh pain that started at the groin crease right next to her hip and radiated down into the outside of her thigh. She had terrible burning, tingling, and searing pain. She could hardly wear pants because the sensation of anything touching the thigh was unbearable. She had already had been diagnosed with a history of meralgia paresthetica or compression of the lateral femoral cutaneous nerve. She had been treated elsewhere and seen several other physicians prior to coming to our office. She had orthopedics evaluate the hip joint, she even had another peripheral nerve surgeon decompress or release the lateral femoral cutaneous nerve. Unfortunately, that nerve surgery did not work for this young lady. She unfortunately continued to have severe pain.
I will take this opportunity to state that there is nothing wrong with decompressing or releasing the lateral femoral cutaneous nerve in the setting of Meralgia Paresthetica. We do this all the time. This is the equivalent of doing a carpal tunnel release for carpal tunnel syndrome in one’s hand. There is only one problem -- the success rate of this operation is known – even in the best of hands – not to be as successful as nerve decompression in the wrist. Why is that? There are several reasons. It could be the patient’s size, the different anatomy, and the fact that there are some positions that we can not avoid given that we are human beings. The lateral femoral cutaneous nerve is easily pinched at the groin when we sit, and for some reason, even if we think we do a “fantastic” job releasing this nerve from the tight bands that can pinch it, the pain still will not go away at times. We do prefer to try to save this nerve most of the time. However, if a patient is overweight, of if the nerve did not respond to previous decompression, or if we suspect that the nerve is injured by another unrelated operation like a hip arthroscopy, or hip replacement, hernia repair, then we typically prefer to remove the nerve. Most patients would rather have permanent numbness to the outside of the thigh than have constant severe pain.
The good news in this young lady is that she was quite thin, so we were a bit surprised that the first decompression did not work well for her. But good news was that when we put this nerve to sleep (performed a nerve block) under ultrasound guidance in the office --- all of her pain resolved, and she loved the numbness that occurred with the block. We even repeated it to make sure it was not a placebo effect. So based on the wonderful response from the blocks, we took her back to the operating room (our first operation) and removed the lateral femoral cutaneous nerve and implanted this into her pelvis. What was very satisfying about this operation is that she had very clear unusual anatomy, that we had never seen before that would put this nerve at clear risk for never recovering from decompression. The nerve traveled through a muscle that is very rare. So rare, that despite having operated on this nerve hundreds of time, we had never seen it, but is it reported in the medical literature. We were quite excited and were very confident that she would improve. And she did improve – a lot! We were extremely excited. Her pain was improved, she could touch the thigh, she could wear normal pants again, she could sit in chairs much more comfortably with the thighs at a normal 90 angle. BUT …. She still has one symptom that was annoying and keeping her from being as active as she would like and getting back to all her favorite activities. Every time she would take a step – she had a non-painful, but annoying electrical zinging that would travel down into her thigh in a similar location. Now this sensation had been present PRIOR to surgery. We thought for sure this would go away with what we had found, but it did not. She was still pleased, but wanted to know if we could further improve these symptoms.
What had we missed? Was there something about her anatomy? Was there a branch that we had somehow missed? Is this just the best that we could expect her to be? Was this patient just making this up? How could we be so close, but not quite to the point where we wanted to be? Should we just stop and accept this? She is better than she was after all. These are difficult questions. These questions take time to figure out, and they take some serious experience to figure out. A “recreational” nerve surgeon – ie one that operates on nerve only once in a while – really can have a very difficult time determining the cause of this apparent partial failure. For the more experienced peripheral nerve surgeon these questions can be very challenging to work out as well, but there are protocols to help us try to figure this out.
We can work through some of these questions of why we got good but only partial relief. Is there another nerve nearby that we missed? Were the techniques not adequate for this particular patient on this particular day? Does the patient have limitations that we did not pick up the first time? Did we put a nerve in a bad location that is easily re-traumatized? Was the patient’s problem simply too far gone to respond to peripheral nerve surgery, and will these techniques simply not work in this particular patient? Do they need to be referred for only medication management, or would a stimulator be a better option?
Typically, we start by believing what the patient tells us. Then we start to investigate the most likely causes. We may repeat nerve blocks, repeat imaging studies, repeat physical exams over time. It takes patience on both the physician and the patient’s part. If after gathering this data, which can take a long time, we can put it together to make a new plan.
That is what we did in our young patient. After this we had two working hypotheses. One, there was a second nerve near by that we did not see because it was stuck in a previous scar and hidden. Two, the nerve that we had previously found, cut, moved, and hidden into the pelvis was for some reason still talking to us and perhaps it moved from where we has put it and was being traumatized with every step. So after careful planning, careful discussion, review of the potential risks and hopeful benefits, discussion of how to approach this we returned to the operating room. We even took another experienced surgeon to assist just in case we found something unexpected. After entering into the pelvis through an incision similar to an appendix incision, we were able to find the nerve that we had previously divided, and it looked very reasonable. However, less than one centimeter away in an area of previous scar tissue that was dense and firm, we found another nerve not previously appreciated traveling into that scar. After careful assessment, this made good sense as the potential cause. A segment of this unnecessary sensory nerve (nerve going to the skin and not muscle) was removed and redirected way from the scar and treated in a manner to try to avoid recurrent problems with the nerve.
The great news is that as soon as she woke up – her tingling with every step was gone, and at 3.5 months she has had no return of these annoying sensations. Overall her original pain is more than 95% gone. We could not be more happy for the patient! She is now getting back to being a normal young lady, increasing her activities and enjoyment of life once again, wearing normal clothes, sitting, walking, engaging in classes and with her friends. The small area of numbness that was left after the two surgical procedures is a welcome relief compared to the intense burning and annoying tingling that she complained of prior to surgery. The area of numbness does shrink with time as healthy nerves grow into the region.
If you or someone you know have severe burning pain, hypersensitivity, and pain in the outside of the thigh that has been unrelieved by conservative measures, if there are no problems with your spine, then the problem can be due to entrapment or injury of the lateral femoral cutaneous nerve. This is called Meralgia Paresthetica. This can occur for a variety of reasons. The most common are diabetes, trauma to the outside of the hip region, previous surgery in the area of the nerve, or it can be idiopathic – meaning we don’t know why the nerve is inflamed. There are many treatment options that can be considered. We would be happy to discuss these with you or someone you know who may be suffering from these symptoms.
If you have had a previous attempt to fix this problem and it has not worked well, or if it only has worked in part, we are also happy to review your case to see if there is anything we can add, or other options that exist for treatment.