Spinal accessory nerve to suprascapular nerve transfer
Patient is placed in the lateral position with head of the operating table raised by 40 degrees . An incision is made parallel to the spine of scapula. The trapezius muscle is elevated from the scapular spine and the space between the trapezius and the supraspinatus muscles is exposed. A thin layer of adipose tissue may occasionally be observed between the two muscle layers. Neurovascular structures covered by a thin epimysium are identified on the undersurface of the trapezius. The SAN is then cautiously isolated from the thin vessels and looped in a vascular tape. The nerve is then traced as distally as possible in order to allow a tension-free anastomosis with the SSN, and finally sectioned with a pair of sharp scissors.
Working laterally along the upper border of scapula, a strong downward traction is applied on the upper border of the supraspinatus muscle to reveal the glistening white suprascapular ligament overlying the suprascapular notch. Suprascapular vessels running superficial to the suprascapular ligament are clipped, and the ligament is divided under direct vision safeguarding the underlying SSN. The nerve is isolated in the fatty tissue just proximal to the suprascapular notch, and divided. The SAN is sutured to the distal segment of the SSN with 10-0 nylon suture under an operating microscope . The trapezius muscle is then sutured back to the spine of scapula using a 3-0 polyglactin suture. Finally, the skin incision is closed without a drain.
Triceps branch of radial nerve to axillary nerve transfer (Somsak transfer)
Patient is placed in the supine position with a silicone pad beneath the affected shoulder, and the affected arm resting on the chest. An incision is made along the posterolateral aspect of the arm, with the upper part of incision curving along the posterior border of the deltoid, and the lower part centered over the triangular space in between the long and lateral heads of the triceps muscle.
The radial nerve and its branch to the long head of triceps are identified in the triangular space. A partial division of the lower edge of teres major enhances the exposure of the motor branch to the long head of triceps muscle. This motor branch that usually terminates into two or three smaller branches is sectioned close to the triceps muscle.
The upper part of the incision exposes the quadrilateral space and the AXN, dividing into its anterior and posterior branches. The anterior branch is dissected intraneurally and transected as proximally as possible.
The triceps branch to the long head is then flipped 1800 and sutured to the anterior branch of the axillary nerve with 10-0 nylon suture under an operating microscope and skin incision is closed without a drain.