The word ‘sympathectomy’ has the ring of something lulling you into a false sense of security. It starts off well – ‘sympath’ – ok, it’s missing the ‘y’, yet still verging on the warm and comforting. But then you reach those final two syllables – ‘ectomy’ – yup, that means surgical removal.
So what exactly is a sympathectomy and can it be effective in reducing the pain of CRPS?
Fight or flight
It’s thought that Complex regional Pain Syndrome (CRPS) may be the result of a problem in the sympathetic nervous system (SNS), which is part of the autonomic nervous system.
The SNS is responsible for stimulating our ‘fight or flight’ response – our body’s primitive, automatic, response that prepares us to ‘fight’ or ‘flee’ from a perceived threat to our survival. In response to a stressor, the SNS triggers various physiological changes; increased muscle blood flow and tension, dilated pupils, accelerated heart rate and respiration, and increased perspiration and arterial blood pressure.
What is a sympathectomy?
A sympathectomy is an invasive procedure that uses either a surgical or chemical approach to interrupt the SNS with a view to increasing blood flow and thereby decreasing the pain of CRPS and neuropathic pain. A chemical sympathectomy uses an injection of either phenol or alcohol to interrupt the SNS by destroying sympathetic nerve tissue. The surgical approach involves severing the sympathetic nerve chain.
A sympathectomy may be carried out near the top of the spine (a cervico-thoracic sympathectomy) or near the bottom of the spine (a lumbar sympathectomy).
Is there any evidence that they work?
In reality, there is exceedingly little good quality evidence on the efficacy of sympathectomies as a treatment for CRPS and neuropathic pain. Indeed, a Cochrane Review in 2013 could find “only one small study (20 participants) of good methodological quality”. The authors of that review concluded:
“The practice of surgical and chemical sympathectomy for neuropathic pain and CRPS is based on very little high quality evidence. Sympathectomy should be used cautiously in clinical practice, in carefully selected patients, and probably only after failure of other treatment options. In these circumstances, establishing a clinical register of sympathectomy may help to inform treatment options on an individual patient basis.”
Further, in one often cited article by Drs Hooshmand and Phillips, the warnings are even starker:
“Complex Regional Pain Syndrome (CRPS) patients should not be exposed to aggravation of pain due to sympathectomy, chemical sympathectomy or radiofrequency sympathectomy.”
“Surgical procedures have no place in treatment of CRPS.”
The overriding suggestion seems to be that the success rate of sympathectomy procedures are low and even where some benefit is achieved, it is usually short-lived. And that’s without considering the risk factors of the procedure itself, particularly for somebody suffering CRPS.
Despite these warnings, the highly worrying reality is that sympathectomy and particularly chemical sypathectomy remains popular with a few pain medicine consultants in the UK, both within the NHS and privately. And despite the warnings above, I am aware from clients that they are sometimes still offered as a treatment option in the early stages of CRPS, not “only after failure of other treatment options.”
This also seems entirely at odds with the new Royal College of Physicians UK “guidelines for diagnosis, referral and management in primary and secondary care” for CRPS which, tellingly, are silent with regard to the use of sympathectomy.
Clearly, anybody offered a sympathectomy for CRPS, particularly in the early stages, needs to quiz their specialist closely on the evidential basis for their recommendation. Certainly, in that situation you cannot be criticised for seeking a second opinion.