Neurolytic lumbar sympathetic blockade: Duration of denervation and relief of rest pain

Abstract

In an objective evaluation, 386 patients with rest pain due to occlusive vascular disease were studied before and after neurolytic lumbar sympathectomy by either 100% alcohol (n=35), 6% phenol in water (n=151) or 10% phenol in Conray 420 contrast medium (n=200). A trained independent observer made assessments of:- (a) Completeness and duration of sympathetic ablation; (b) Degree and duration of pain relief; (c) Changes in skin temperature and skin plethysmography; (d) Completeness of coverage of antero-lateral aspects of L2, L3, and L4 by contrast medium (in patients receiving 10% phenol). (e) Side effects, including L1 neuralgia and postural hypotension. Mean duration of sweat test modification (6.0 ±1.0 months) and pain relief (5.9 ±0.6 months) were similar; onset of pain relief also coincided with onset of sympathetic blockade and increase in skin blood flow. This strongly pointed to sympathetic denervation as the basis for the relief of rest pain rather than a placebo response. Complete pain relief was achieved in 49% of patients, 31% had partial relief and 20% none. In the absence of pre-existing gangrenous changes a higher percentage of patients had complete or partial relief (84%) compared to those with gangrenous changes (56%). Significant postural hypotension was not observed. Frequency of L1 neuralgia differed markedly for the three agents: 100% alcohol >6% phenol in water>10% phenol in Conray. It is concluded that neurolytic lumbar sympathectomy is an effective method of relief of rest pain with the advantage over surgical sympathectomy of performance without general anaesthesia on an outpatient basis. It is estimated that, in a series of the size reported in this paper, the potential economic benefit could be a saving of the order of $360,000. The technique deserves further controlled evaluation in comparison to surgical sympathectomy.