Decompression nerve surgery for diabetic neuropathy: a structured review of published clinical trials

Abstract

AimTo assess lower extremity decompression nerve surgery (DNS) to treat the consequences of diabetic distal symmetric peripheral neuropathy (DPN).Research design and methodsMEDLINE, PubMed, and related registries were searched through December 2017 to identify randomized, quasi-randomized or observational trials that evaluated the efficacy of lower extremity DNS on pain relief (primary outcome) or other secondary outcomes. Observational studies were included, given investigators’ reluctance to use sham surgery controls. Outcome effect size was estimated, and a weighted average was calculated.ResultsEight of 23 studies evaluated pain relief, including a double-blind randomized controlled trial (with a sham surgery leg), an unblinded trial with a nonsurgical control leg, and 6 observational studies. All reported substantial pain relief post-DNS with average effect sizes between two and five. Unexpectedly, the double-blind trial showed improvement in the sham leg comparable to the DNS leg and exceeding the improvement observed in the nonsurgical leg in the unblinded study. Sensory testing showed generally favorable results supporting DNS, and nerve conduction velocities increased post-DNS relative to deterioration in controls. Ultrasound revealed fusiform nerve swelling near compression sites. Morphological results of DNS were generally favorable but inconsistent, whereas hemodynamic measures showed a positive effect on arterial parameters, as did transcutaneous oximetry (improved microcirculation). The incidence of initial and recurrent neuropathic diabetic foot ulcers appeared reduced post-DNS relative to the contralateral foot (borderline significant).ConclusionThe data remain insufficient to recommend DNS for painful DPN, given conflicting and unexpectedly positive results involving sham surgery relative to unblinded controls. The generally supportive sensory and nerve conduction results are compromised by methodological issues, whereas more favorable results support DNS to prevent new or recurrent neuropathic foot ulcers. Future studies need to clarify subject selection vis-à-vis DPN vs superimposed compressed nerves, utilize appropriate validated instruments, and readdress use of sham surgical controls in light of recent results.

Comment on IWGDF ulcer prevention guidelines

“…Sadly, there is neither. While evidence for ND may not be of Level 1 EBM quality, the evidence against its use does not exist above the level of persistent sceptical opinion 2,3 . Only with stronger science will such contradictory opinions be resolved.…”

“…While evidence for ND may not be of Level 1 EBM quality, the evidence against its use does not exist above the level of persistent sceptical opinion. 2,3 Only with stronger science will such contradictory opinions be resolved. Now consider that the apparent bias against the nerve decompression procedure might be owing to a lack of appreciation of the dual nature of diabetic peripheral neuropathy (DPN) and a differ- We now know that in DPN, local nerve compression and its sequelae need not be permanent nor irremediable.…”

“…Neurologists have been reluctant to credit the decompression surgery for comfort restoration in DPN, citing potentials for bias or placebo effects and an unexpected bilateral benefit of unilateral ND. 2,3 Addressing this scepticism, Rozen et al have presented in a 2017 ADA Scientific Session their Level 1 RCT study of ND and DPN pain relief incorporating sham surgery to eliminate bias and placebo risks. 13 The results show durable VAS pain score reductions from >8/10 to <3/10 which last over 4 years.…”

The natural history of tarsal tunnel syndrome in diabetic subjects

“…38 , 39 Although controversy towards LEND surgery continues to exist, our study provides the necessary evidence to progress to high-quality data. 40…”

Diabetic Neuropathy Collection: Treatment of Diabetic Neuropathy

“…UA: A number of studies have looked at decompression surgery [21]. So this is, for instance, decompression of the lower limb nerves and also tarsal tunnel surgery.…”