Chemonucleolysis for disc herniation: An updated review of the literature

Herniated intervertebral disc is one of the common causes of neck/low back pain and/or neuralgia. The vast majority of such symptoms improve with conservative treatments that include rest, medications, and physical therapy. In case of failure, many minimally invasive disc techniques have been emergedas alternative optionsto surgical treatments, to avoid their potential complications and possiblytheir suboptimal results. Chemonucleolysis is one of the minimally invasive disc decompression techniques thatare based on the intradiscal injection of chemonucleolytic agents causing dehydration of the disc matrix, resulting into a reduction of the intradiscal pressure and disc voulme, and hence, alleviation of the nerve root compression. These chemonucleolytic materials include chymopapain, collagenase, oxygen-ozone mixture,radio-opaque jellified ethanol “Discogel, chondroitinasesulphateABC, and matrix metalloproteinase (MMP). Nowadays, chemonucleolysis using the oxygen-ozone mixture and radiopaque gelified ethanol have gathered the most support for use in clinical practice.This article aims to clarify the mechanisms of action, selection criteria, procedural technique, outcome assessment, efficacy, and safety of a variety of intradiscalchemonucleolytictherapiesused for the treatment of herniated discs.