Surgical Procedure for Regenerative Peripheral Nerve Interface (RPNI) for Neuroma Management

To begin, position the subject arm, depending on the site of the painful neuroma, and plan for the skin incisions. Make a skin incision on the painful neuroma site. Using blunt dissection, identify the nerve with the painful neuroma.

Gently isolate the nerve and the neuroma with fine instruments. Using a commercial nerve cutting preparation set or a sharp scaffold, mobilize the nerve and transect the neuroma up to the healthy NeuroFasicals. Now, with straight micro scissors, perform longitudinal intradural dissections from the distal end of the nerve for approximately two to three centimeters.

Prepare the NeuroFasicals depending on the amputation level and the size of the nerve. After identifying a healthy native donor muscle, make a skin incision over the muscle, and use dissecting scissors to dissect the muscle graft along the main axis of the muscle fibers. Gently excise adipose tissue, and the muscle fascia from the muscle graft.

Keep the harvested muscle in a moist gauze, soaked in a sterile 0.9%sodium chloride solution until use. Expose the nerve previously isolated, and divide it into fasicals. Position the fasical on the muscle graft, ensuring the distal stump is in the central or proximal third of the graft, and parallel to the muscle fibers.

Using six zero non-resorbable monofilament sutures, secure the nerve stump in the center of the longitudinal axis of the muscle graft. Place an additional stitch at the proximal edge of the muscle graft. Fold the muscle graft around the fasical, and secure it with a six zero interrupted, or continuous non-resorbable monofilament suture.

Similarly, suture the other muscle grafts around the nerve. Perform blunt dissection in the residual limb to provide a protected area where each RPNI can lie comfortably and out of the weightbearing surfaces of the lip. Then, offset the location of each RPNI in series.

Finally, close the surgical wounds in layers.