Study of the spread of scarring along the damaged area of the limb nerve after gunshot and explosive injuries

Background. Determining the true size or extent of the nerve defect after damage and excision of the post-traumatic neuroma is fundamental in the microsurgical treatment of the patient. It is assumed that the length of the scar in the nerve may depend on the nature of the combat wound of the limb, gunshot or mine-explosive. Determining the extent of scarring in the nerve in cases of these two types of injury may provide an opportunity to establish a relationship with the type of injury or to disprove such a relationship. This should help in the tactics of surgical treatment. Methods. 50 samples of damaged peripheral nerves were studied, including 36 nerves of the upper limb and 14 nerves of the lower limb. Microsurgical operations were performed after the injury in an average of 5.4±0.4 months (min=2 months, max=17 months). The specifics of scarring in the nerve were investigated by histochemical method and the specific density of collagen at different distances was calculated. A map of scarring was created for each nerve sample to determine the length of the scar. Results. Based on the mapping of nerve samples, the average length of the scar was determined, which reached 40-50 mm in the nerves (Me=35.5 mm, Q1=30.0, Q3=55.2, min=19 mm, max=120 mm), where after a gunshot wound - 37.5±5.5 mm (Me=30.0) and mine-explosive wound - 43.5±8.0 mm (Me=36.0). Morphological features of nerve scarring after these two types of damage did not differ (p=0.29), neither in length nor in scar density. Conclusion When calculating the true defect of the nerve, one should take into account the spread of the scarring process in the nerve, which in a combat wound is about 30-50 mm. The length of the scar in the nerve does not depend on the nature of the striking projectile, which proves the critical importance of the energy of the injury.