Vascularized Composite Upper Limb Allograft Harvesting for Proximal Arm Allotransplantation

Our research focuses on developing standardized protocols for procuring and preparing proximal upper limb allografts to ensure anatomical fidelity, enable reproducible surgeries and enhance functional and immunological outcomes in upper extremity vascularized composite allotransplantation.

Our center focuses on various methods to enhance nerve regeneration, including nerve conducts, nerve wrapping, and stem cell-based therapies. The advances in nerve regeneration we are investigating may be directly applicable to the transplantation step following this protocol as functional outcome in VCA largely depend on the extent of neural recovery.

Upper limb allotransplantation remains a rare and highly specialized procedure. Despite existing literature on procurement techniques, a comprehensive stepwise protocol is lacking. Establishing such a standardized protocol is essential to ensure reproducibility, optimize the graft quality and enhance surgical outcomes.

Our protocol results from a collaboration with the automated team in France, Lyon, pioneers in VCA with extensive experience in proximal limb transplantation. It benefits from their valuable expertise and long-term data on patient outcomes.

The development of a standardized procurement protocol for upper limb allografts will improve surgical reproducibility. It'll also facilitate experimental research in VCA by enabling control graft harvesting for laboratories to this.

We will focus on ex vivo and in vivo graft perfusion strategy along with stem cell based approaches to promote human tolerance and improve outcomes in VCA.

[Narrator] To begin use a surgical scalpel blade number 15, to make a circumferential fish mouth incision just proximal to the deltoid humeral insertion. Using fine needle cautery and a pair of Adson tissue forceps, raise the volar proximal skin flap, ligate proximally and divide the cephalic veins. Detach the pectoralis major from the humerus using monopolar diathermy to expose the coracobrachialis. Then use a scalpel to recline the deltoid from the clavicle and acromion to access the scapular insertion of the long portion of the biceps brachii. Isolate and detach both the long and short portions of the biceps brachii and the coracobrachialis. Detach the pectoralis minor from the cricoid process to access the brachial plexus. With scissors, dissect and transect the median, ulnar, radial and musculocutaneous nerves in their proximal third or at the cord level. Cut the axillary nerve to allow muscular involution of the deltoid. Expose the brachial artery and veins up to the axillary vessels and tag them. Make a longitudinal mark along the bicipital groove to facilitate accurate rotational alignment during osteosynthesis. Then use an oscillating saw to perform a transverse osteotomy of the humerus at the preoperatively planned level. Raise the dorsal proximal skin flap using fine needle cautery and a pair of Adson tissue forceps. Clip any superficial veins proximally using hemostatic clips. Use a scalpel to isolate and detach the long and lateral heads of the triceps brachii from their proximal origins and the posterior head of the deltoid from the scapula. Ligate the axillary vessels proximally and divide them. Make a double ogival shaped incision with the proximal extremity at the cricoid level and the base 10 centimeters more distal. Create a superior acromioclavicular flap delimited by the delta pectoral interval and an inferior axillary flap. Extend the incision proximally to the sternoclavicular joint. Then continue 10 centimeters up to the posterior border of the sternocleidomastoid muscle. Using a scalpel, detach the anterior head of the deltoid from the clavicle. Then detach the middle head from the acromion and the posterior head from the scapula. Cut the posterior head perpendicularly to the scapular spine 10 centimeters from the acromion. Now detach the pectoralis minor from the cricoid process. Then detach the short head of the biceps brachii and the coracobrachialis from the cricoid. Detach the clavicular insertion of the pectoralis major. Make a subcutaneous dissection to expose the pectoralis major. Then using monopolar diathermy, transect through the muscle belly, leaving all the tendons on the humeral insertion with an additional 10 centimeters of muscle. Perform an osteotomy of the clavicle to access the proximal portion of the vessels and the brachial plexus. Dissect and place vessel loops around the subclavian artery and vein at a proximal level. Identify the lateral, medial, and posterior cords of the brachial plexus and transect them proximally to the origins of their terminal branches using scissors. Dissect the subclavian vessels down to the axillary vessels using scissors and tag them. Ligate all collateral arteries and veins from the axillary vessels destined for the thorax using hemostatic clips or braided absorbable sutures. Using a scalpel, isolate and detach the long head of the biceps brachii from its proximal origin for future humeral tenodesis. Using a scalpel, incise the tendon of the subscapularis and the glenohumeral joint capsule at the neck of the scapula. Transect the tendons of the supraspinatus, infraspinatus, anteriors minor muscles posteriorly to the joint at the same level. Disarticulate the glenohumeral joint to harvest the humeral head with the graft. Mobilize the humerus laterally. Detach the long head of the triceps from its proximal origin with a scalpel, and remove the latissimus dorsi and teres major from their humeral insertions. Finally, ligate and divide the axillary and subclavian vessels proximally. The average diameters of major vessels and brachial plexus cords at the coracoid level during glenohumeral transplantation were calculated. Among these structures, the axillary artery has the greatest diameter, followed by the axillary vein and lateral cord with the medial cord having the smallest diameter. The average diameters of vessels and nerves at the humeral neck level during transhumeral transplantation are presented with the brachial artery having the greatest diameter while the cephalic vein displays the smallest.