Fast-acting and injectable cryoneurolysis device

Abstract

Cryoneurolysis is an opioid-sparing therapy for long-lasting and reversible reduction of pain. We developed a nerve-selective method for cryoneurolysis by local injection of ice-slurry (− 5 to − 6 °C) that induced decrease in nocifensive response starting from about a week after treatment and lasting up to 8 weeks. In this study, we test the hypothesis that injection of colder slurry leads to faster onset of analgesia. Colder slurry (− 9ºC) was injected around the rat sciatic nerve to induce cryoneurolysis. Hematoxylin and Eosin (H&E) staining was used to examine histologic effects on surrounding tissues. Coherent anti-Stokes Raman scattering (CARS) microscopy was used to study effects on myelin sheaths. Functional tests were used to assess changes in sensory and motor function in the treated hind paw. No inflammation or scarring was detected in surrounding skin and muscle tissues at day 7 post slurry injection. Functional tests showed rapid onset reduction in mechanical pain sensitivity starting from day 1 and lasting up to day 98. CARS imaging demonstrated disintegration of myelin sheaths post treatment followed by complete recovery of nerve structure by day 140. In this study we showed that colder slurry (− 9 °C) produces more rapid onset and longer duration of analgesia, while remaining nerve-selective

Novel Techniques and Local Anesthetics for Perioperative Pain Management

“…On the other hand, the use of cryoneurolysis, an opioid-sparing therapy in which cryoprobes freeze peripheral nerves, is becoming increasingly popular [55]. Cryoneurolysis causes nerves to undergo Wallerian degeneration, allowing relief from pain for up to 90 days as nerves regenerate [56,57].…”

“…New techniques and devices for cryoneurolysis are being tested that utilize local injection of a "cold slurry" containing normal saline with 15% glycerol from −5°C down to −9°C. This can minimize the limitations of the current Novel Techniques and Local Anesthetics for Perioperative Pain Management DOI: http://dx.doi.org/10.5772/intechopen.1002929 cryoneurolysis devices [55]. There is also ongoing research to optimize probe design [73].…”