Decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy

Background: Symmetrical peripheral neuropathy is a common complication of diabetic neuropathy. No treatments are known to be effective for progressive pain and sensory loss associated with diabetic neuropathy. Alternative effective treatment strategies have been sought. Objectives: To systematically review the evidence from randomized controlled trials concerning the role of decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy. Search strategy: We searched the Cochrane Neuromuscular Disease Trials Register (May 2006), CENTRAL (The Cochrane Library, Issue 2 2006), MEDLINE from (January 1966 to August 2006), EMBASE (from January 1980 to August 2006), LILACS (from January 1982 to August 2006), and CINAHL (from January 1982 to August 2006). Selection criteria: We included all randomized or quasi-randomized controlled human trials in which any form of decompressive surgery of the lower limbs nerves had been used to treat diabetic symmetrical distal polyneuropathy (DSDP) compared with no treatment or medical therapy. Patients with DSDP were included if they had decompression (with or without neurolysis) of at least two of the following nerves in both lower limbs, for the treatment of DSDP: the posterior tibial nerve (including calcaneal, medial and lateral plantar nerves), deep peroneal nerve at the ankle, common peroneal nerve at the knee, lateral femoral cutaneous nerve and sural nerves in the posterior calf region. The primary outcome measure was the change in pain measured by the visual analogue scale (VAS) between the baseline and a follow-up period of greater than three months. Data collection and analysis: We identified 142 publications from the above search strategies. The three authors of this manuscript reviewed abstracts of all papers independently. Only eight of these were considered relevant to the question at hand. The data from these 8 studies were entered onto standardized data extraction forms. We planned to use Review Manager to pool the results from appropriate studies comparing the same treatments; dichotomous outcomes to obtain pooled relative risks (RR); measured outcomes to obtain pooled weighted mean differences; and a fixed-effect analysis unless there was evidence of serious heterogeneity between studies sufficient to justify the use of random-effects analysis. Main results: This review failed to identify a single randomized controlled trial or any other well designed prospective study controlling for the non-operated limb that showed improvements in pre defined end points after decompressive surgery. Authors' conclusions: The results of this review suggest that the role of decompressive surgery for diabetic symmetric distal neuropathy is unproven.