Vascularized Composite Hand Allograft Procurement and Preparation for Distal and Proximal Forearm Allotransplantation: A Stepwise Approach

Our research focuses on refining the procurement and preparation techniques for upper limbal grafts aiming to optimize anatomical preservation, improve surgical efficiency, and enhance outcomes in upper extremity allotransplantation.

Recent VCA innovations include proximal upper limb allotransplantation, wall high and face transplants, and progress in tolerance and diction using chime rhythm and engineered regulatory T cells across all transplant types.

Advances rely on 3-D imaging, perfusion preservation systems, nerve regeneration models, and immunomonitoring platforms to optimize graft viability, surgical precision, and long-term transplant tolerance.

The main challenges include managing chronic rejection, reducing immunosuppressive toxicity, ensuring functional nerve regeneration, and standardizing graft preparation across centers.

We define a repredictable technique for opening biograft preparation that preserves key neurovasculature and facilitate surgical opening in both proximal and distal forearm transplants.

[Narrator] To begin, obtain an arm specimen. Using an number 15 surgical scalpel blade make a circumferential fish-mouth incision at the mid-arm level. Raise the volar proximal skin flap using fine needle cautery and a pair of Adson tissue forceps. Ligate the cephalic and basilic veins proximally, then divide them. Expose the brachial artery and veins a few centimeters above the elbow crease. Ligate them proximally and divide the vessels. Then dissect along the medial arm using scissors. Use a scalpel to transect the median nerve and ulnar nerve, which are located deep to the medial intermuscular septum. Now raise the dorsal proximal skin flap with fine needle cautery and Adson tissue forceps. Clip any superficial veins proximally with hemostatic clips. Identify the radial nerve deep to the lateral intermuscular septum. With a scalpel, transect the radial nerve proximal to its branches for brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis. Next, isolate and transect the biceps, brachialis, and triceps muscle bellies using monopolar diathermy. Perform a transverse humerus osteotomy a few centimeters above the elbow joint using an oscillating saw. Mark the medial and lateral epicondyles to guide the fish-mouth incision below the elbow joint and make the incision with a number 15 surgical scalpel blade. Use fine needle cautery and Adson tissue forceps to raise the volar skin flap. Ligate the cephalic and basilic veins proximally and divide them. Next, inside the antibrachial fascia with a scalpel. Identify and transect the brachial artery and median nerve under the lacertus fibrosis, located ulnar to the biceps brachii tendon, with a pair of scissors. Now transect the pronator teres and forearm flexor muscle mass through their proximal bellies using monopolar diathermy. Then identify and transect the ulnar nerve where it exits the cubital tunnel. Sever the elbow flexors near their distal insertions with monopolar diathermy to expose the ulnar elbow joint capsule and the proximal ulna. Then transect the mobile wad and the common extensor mass at their proximal bellies to identify the radial nerve and expose the radial elbow joint capsule. Incise the anterior elbow joint capsule with a scalpel, then fully flex the elbow and raise the dorsal skin flap using fine needle cautery and Adson tissue forceps. With a scalpel, isolate and transect the triceps tendon. Incise the posterior elbow joint capsule to fully disarticulate the elbow and detach the limb. With a number 15 surgical scalpel blade, make a longitudinal median volar incision, extending from proximal to distal, to the mid forearm level. Make a longitudinal dorsal incision along the shaft of the ulna extending up to 14 centimeters below the olecranon. Now raise the medial skin flap using fine needle cautery and a pair of Adson tissue forceps. Dissect and separate the basilic vein and the medial antibrachial cutaneous nerve with scissors. Raise the lateral skin flap and dissect the cephalic vein and the lateral antibrachial cutaneous nerve with scissors. With scissors, dissect the ulnar nerve and median nerve until the origin of the flexor carpi ulnaris branch and the origin of the pronator teres branch respectively. Then dissect the radial nerve and identify the brachioradialis, extensor carpi radialis longus and extensor carpi radialis brevis. Tag the motor branches and transect them at their origins from the radial nerve. Then separately tag the superficial and deep branches of the radial nerve. Next, dissect the brachial artery and its vena comitanties distally to their division into radial and ulnar arteries. With a scalpel, elevate the flexor and extensor muscle mass origins from the medial and lateral epicondyles in a subperiosteal plane, then elevate the brachioradialis from its humeral insertion. Then cut the radius distally from the biceps tendon insertion to allow for plate fixation. Reflect the brachialis proximally and the forearm muscle mass distally from the proximal ulna by anterior and posterior subperiosteal dissection. Continue to elevate the forearm muscles from the radius and ulna with a scalpel until three holes of the dynamic compression plates can be accommodated beyond the planned osteotomies. Make mid-axial volar and dorsal incisions distally up to the wrist level using a number 15 surgical scalpel blade. Through the volar incision, release the carpal tunnel. Raise the radial and ulnar skin flaps along with the anti brachial fascia using fine needle cautery and Adson tissue forceps. Then carefully preserve the distal forearm skin perforators on both flaps. Cut off the radial skin flap including the cephalic vein and lateral antibrachial cutaneous nerve using scissors. Similarly, dissect off the ulnar skin flap, including the basilic vein and medial antibrachial cutaneous nerve. Identify and excise the brachioradialis muscle using fine needle cautery. Dissect and expose the radial sensory nerve underneath. Open the first dorsal compartment with a scalpel and elevate the abductor pollicis longus and extensor pollicis brevis tendons. Isolate the extensor carpi radialis longus and extensor carpi radialis brevis, then free the extensor pollicis longus from its sheath. Identify the extensor indicis proprius, extensor digitorum communis, and extensor digiti minimi, Then elevate the extensor carpi ulnaris tendon. Dissect the radial artery and its vena comitanties using scissors and Adson tissue forceps. Then isolate the flexor carpi radialis and excise the palmaris longus with a scalpel before dissecting the median nerve in the same region. Now identify each tendon of flexor digitorum superficialis, flexor pollicis longus, and the four tendons of flexor digitorum profundus, and elevate the flexor carpi ulnaris. Dissect the ulnar artery and ulnar nerve carefully with scissors to identify the dorsal sensory branch of the ulnar nerve. Then use fine needle cautery to excise the pronator quadratus. Expose the volar surface of the radius and the ulnar side of the ulna until three holes of the osteosynthesis plates can be accommodated beyond the planned osteotomies. In the proximal forearm, the median nerve had the largest average diameter at six millimeters, followed by the brachial artery at 5.17 millimeters, and the ulnar nerve at 4.75 millimeters. In the distal forearm, the ulnar artery had the largest diameter at 4.25 millimeters, followed closely by the radial artery and the ulnar nerve, each measuring four millimeters.