Mechanical anastomosis of nerves: a histological and functional comparison to conventional suturing.

The use of a mechanical coupling device in microsurgery offers speed of application in addition to a secure vascular union. Despite its success in a vascular setting, mechanical coupling device nerve repair remains to be studied. Forty-five male rats were tested over 7- and 14-week study periods. One half of the animals underwent primary suture repairs for transected sciatic nerves, and the remainder of the animals had their nerves repaired using a mechanical coupling device. Postoperative analysis consisted of histological evaluation of pre- and postrepair site nerve morphology (axonal continuity and counts) as well as functional testing using walking track analysis. Mechanical coupling device coaptation of the nerves using the epineurium was done in approximately one half the time compared with conventional suturing. After both 7 and 14 weeks postoperatively, walking track analysis showed no difference in the amount of functional return between the two repair groups. No animal exhibited complete return of function. Axonal continuity occurred across both repairs without significant difference in their pre- and postrepair axonal counts. Although no clear advantage was seen in this study, the concept of mechanical nerve coupling merits further investigation based on its potential clinical utility.