neurorrhaphy

Neurorrhaphy is the surgical repair of a severed peripheral nerve, performed to restore continuity between proximal and distal nerve stumps after traumatic transection or iatrogenic injury. The aim is to enable axonal regeneration along the distal stump to reinnervate target muscles or sensory receptors. Outcomes depend on factors such as gap length, nerve type, patient age, and time elapsed since injury.

Several techniques are used. End-to-end neurorrhaphy, or primary neurorrhaphy, involves direct coaptation of the nerve ends under magnification. Epineurial repair sutures the outer layer of the nerve, while fascicular or perineurial repair aligns individual fascicles to improve specificity of reinnervation. When a gap prevents direct apposition, interpositional nerve grafts (often autografts such as sural nerve) or allografts bridge the defect. Grafts require tension-free anastomosis and careful alignment of donor and recipient fascicles.

Microsurgical methods employ specialized equipment and ultra-fine sutures, typically 8-0 to 11-0 nylon, and may use fibrin glue as an adjunct. Accurate fascicular alignment and protection of the repair site are emphasized to reduce misdirection of regenerating fibers. Postoperative care includes immobilization followed by graded rehabilitation to maximize functional recovery.

Indications include clean transections with viable proximal and distal stumps and the absence of extensive scar tissue. Primary neurorrhaphy is favored when feasible; grafting is considered for larger defects or delayed repairs. Secondary neurorrhaphy may be performed if initial repair yields insufficient recovery.

Outcomes vary with injury characteristics and timing. Sensory recovery may occur earlier than motor recovery, and complete restoration is not guaranteed. Complications can include neuroma formation, scar-related impedance, misrouting of fibers, and incomplete reinnervation.