Neurolysis

NEUROLYSIS (from Greek neuron - nerve and lysis - liberation), the liberation of a nerve from the scar tissue constricting it. It was introduced into surgical practice almost simultaneously with nerve resection and nerve suture. At the present time, neurolysis represents one of the important surgical measures on the peripheral nervous system. A distinction is made between external neurolysis (exoneurolysis) and internal neurolysis (endoneurolysis). External neurolysis is the liberation of a nerve from scars enveloping it from the outside. The operative technique for cases where adhesions involve only the epineurium is very simple. The scar tissue is easily removed with a scalpel together with the outer sheath of the nerve (avoid isolating the nerve by blunt means—with a probe, gauze ball, etc.). In the presence of extensive scar masses firmly fused with the nerve trunk, its liberation presents significant difficulties. In these cases, it is necessary to observe special caution when isolating muscular (motor) branches to avoid damaging them. Upon completion of isolation, the nerve trunk must be carefully examined

Figure 1. Liberation of the nerve. The dashed line indicates the site of resection.

by palpation to determine intraneural damage (tears, neuromas, scars). In the absence of endoneural changes, the operation of external neurolysis ends here. Sometimes neurolysis is complicated by the presence of a bone callus compressing the nerve. In these cases, to liberate the nerve trunk, it is necessary to resort to the help of

Figure 2. Suturing of the nerve after partial resection.

bone instruments. Measures to prevent the new development of scars around the nerve after neurolysis are the same as those after nerve suture (see). Internal neurolysis is the liberation of individual nerve bundles from scar tissue that has developed within the thickness of the nerve trunk. The methodology of the operation was developed mainly by Stoffel. The separation of the bundles begins within the limits of the healthy section, then each bundle is sequentially isolated from the scar tissue. The operation is applicable only in those cases where intraneural scars occupy a limited extent. In the presence of extensive scar masses, endoneurolysis proves technically unfeasible. In these cases, the affected section of the nerve is resected and its ends are sutured (Figs. 1 and 2). As a modification of endoneurolysis, one can consider the "nerve combing" (hersage) used by French authors—longitudinal splitting of the nerve into bundles with the help of thin needles or a series of silk threads. Of similar significance are the longitudinal nerve tears used in some cases in the presence of transverse scar bridges. The results of neurolysis are usually quite good. After 2-3 days, the symptoms of irritation disappear, and after 2-3 weeks, the function of the nerve is restored.