6 Principles and techniques for facial allotransplantation


6 Principles and techniques for facial allotransplantation

Bernard Devauchelle, Sylvie Testelin, Stéphanie Dakpé

1 Introduction

Conventional head and neck reconstructive procedures achieve variable results in reconstruction for extensive facial defects. Often, numerous staged surgical procedures result in less optimal or unsatisfactory outcomes. In a face with extensive disfigurement, vascularized composite allotransplantation (VCA) has the potential to restore both esthetics and function. Since the first such face transplantation procedure in 2005 [Devauchelle et al, 2006], at least 37 face transplants have been performed worldwide until 2014 [Khalifian et al, 2014]. The small number is due to the complexity of the procedure, the necessary immunological suppression for organ transplantation, and the consequences of the lifelong treatment. In terms of results, this procedure is a real solution for large disfigurements from severe trauma, large malformations, or extensive benign tumors. However, it is currently achieved at a significant cost of immune suppression.

A facial VCA is a multidisciplinary operation with the need for a complex team [Dahlborg et al, 2014]. The authors specify the conditions for VCA in terms of the surgical procedure (both for recipient and donor), planning and management of the VCA, organization, immunological treatment and monitoring, some psychological and ethical features, followup, complications, and some thoughts on the indications for face transplantation.

2 The decision for vascularized composite allotransplantation and necessary preparations

The main prerequisite for a face transplant is when the best result can only be achieved by composite tissue beyond what can be practicably provided by local, regional or distant autogenous tissue. These characteristics include tissue type, topography and extension of defect.

There are three different steps in planning: (1) analysis and preparation of the recipient, (2) the selection of the donor and then (3) management and organization of the operative day. The patient selection is obviously essential. In France, since 2006 two teams have had the authorization to perform five facial VCA, each with the objectives of functional and morphological restitution of the face. The patient should be carefully interviewed many times. Particularly important is the evaluation of the psychological background. Reliability and compliance should be evaluated by a psychiatrist. An immunologist must define and predict the immunosuppressive protocol and the monitoring, risks and potential complications. The patient must have the capacity to follow a lifelong treatment which may have fatal consequences.

The patient is fully and carefully informed several times about all aspects of VCA and his/her consent should be obtained long before the operative day.

The preoperative imaging is determined by the type of defect but at a minimum a computed tomographic (CT) angiogram is performed and often magnetic resonance imaging. An ultrasonography of the available cervical vessels is required, and an electromyogram may be useful to evaluate the function remaining in the facial muscles and nerves. A 3-D model of the defect and modeling of the recipient bone and soft tissue should be performed to facilitate and visualize the skeletal and soft-tissue complexity of the defect ( Fig 6-1 ).

Fig 6-1a-b Digitalized model showing the three layers of the transplant: skin covering (yellow), muscle structure (red), and mandibular bone (green).

A surgical navigation or computer-assisted protocol is sometimes used.

For each recipient patient, the defect is carefully analyzed and documented (eg, photography, videos, radiography, CT, 3-D printing). The transplant is then precisely defined and dissections are planned. Surgeons, residents, nurses and specialists for prosthesis fabrication are involved. Those dissections define and allow understanding of the exact size, depth (eg, muscle, nerves, bone), and extension of the transplant, with respect to the esthetic and functional units. All details, descriptions, technical points and decisions are carefully reported in a protocol which constitutes the basis of the requested document submitted to the French national agency (Agence de la Biomedicine), which controls all types of procurement. Similarly, the team manager will define the donor criteria: age, gender, blood group, skin color matching, and the necessity of “no contraindication,” such as previous facial surgery, scars, or other pathologies.

The protocol for donor facial mask preparation is essential, and is performed after the facial procurement. This mask is an essential point for the family, so that they will be able to see their relative without major visible changes after transplant harvest.

As soon as the authorization of the French Agency of Biomedicine is obtained, all team members are listed for an on-call process (ie, anesthesiologist, nurses, surgeons including residents, prosthetist). The distribution of the different assignments should be decided by the responsible team leader who coordinates all steps and people. Additionally, a list of specific materials, devices, and files is prepared.

2.1 Waiting time

This period is critical because each member must be motivated to be able to be mobilized at any time. The team leader should organize and control the preparation for the operative day; the patient should be frequently contacted and regularly interviewed. Follow-up is carefully organized and the psychological, medical, and physiological goals are defined. The final decision is always with the patient, so that contact, trust and regular discussions are crucial to prepare for a smooth operative day.

2.2 Operative day

When the leader is alerted that a corresponding potential brain-dead donor is somewhere in France, the first decision must involve analysis of a picture of the potential donor and then to accept or refuse the donor. The coordination team will ask the family, who had already accepted the organ procurement permission, if they would also accept to give a part or the whole face of their relative. In the case of a positive decision, the surgery is scheduled, and all members of the transplant team are notified to prepare and proceed according to the protocol. At the same time, the recipient patient is also contacted to come to the hospital to sign a new consent form and be prepared for surgery.

As soon as the positive answer from the donor’s family is known, the patient will then receive the first immunosuppressive treatment. The decision on the timing of the operation is taken, and the distribution into two teams (one near the recipient to prepare the defect and one who will travel to the donor to harvest the face transplant) is carefully organized depending on the city and distance to the donor. The specific members and material to manufacture the donor face mask will accompany the latter part of the team near the donor. For now, there is no agreement in France to transport the brain-dead donor near to the recipient, which would make the procedure easier.

2.3 Team near the donor

For us and other transplant surgeons [Petruzzo et al, 2012] the face transplant procurement is always done first before other organs are harvested because the facial dissection should be done carefully on a body with the heart beating in the way that the face transplant will exactly match the defect as decided during the dissection procedures.

  • First step—low level tracheotomy, if not previously made.

  • Second step—print of the donor face to reconstitute the silicone mask for the end of the procedure.

  • Third—surgical steps, depending on the size and topography; all steps will follow the preoperative dissection.

    • Precise drawing of the skin margins.

    • Skin incision and progressive dissection from upper margin to the cervical area toward the vessel dissection of the chosen vascular pedicle (ie, facial arteries, carotid arteries, external and internal jugular veins).

    • All nerves and their branches (sensory and motor) should be respected and marked to facilitate coaptation.

    • All facial muscles and ducts involved will be identified and marked.

    • In case of bone inclusion, the preoperative dissection will define the types and the orientation of the osteotomies. Problems arise if only one jaw is included in the VCA, and the recipient and donor jaw do not match. The possibility to remove and replace the opposite jaw should always be favored because of problems in the dental occlusion, which will never be better than after a bimaxillary incorporation (if a replacement of both jaws is not accepted, it will be necessary to build a temporary occlusal dental splint). The inferior alveolar nerve should be resected with a lengthening process by infratemporal dissection. For the infraorbital nerve, the removal of the infraorbital bone margin permits dissection to the pterygoid space. Teeth are often transplanted without any preparation because they belong completely to the vascularized transplant.

  • The tongue and the soft palate can also be harvested. However, a careful dissection of all the suprahyoid muscles attached to the hyoid bone which can be inserted in the transplant and the muscles of the pharyngeal wall to restore the oropharyngeal motility are necessary.

  • At the time of the final venous and arterial dissection (usually external carotid or its branches), the time should be noted because it constitutes the beginning of the ischemic time, which is imperative regarding the functional recovery and the vitality of the transplant.

In our group at the same time a forearm flap is also dissected as “sentinel flap” because serial skin biopsies of allogenic skin are needed for life. Thus, it was decided to perform a skin sentinel flap for biopsies to avoid any additional facial scarring.

After that the transplant is prepared with a washout by a serum solution and then conservative preparation is done, which functions as a transporting liquid and for organ preservation. A part of the team may leave the donor operating room to join the recipient operating room. In the operating room with the donor, the other teams then harvest the other organs. During that time, the prosthetist and one or two assistants prepare and build the silicone mask according to the first imprint. This includes coloration to match and respect the cadaver. After the donor surgery is completed, the restitution of the face of the donor is achieved due to an exact adaptation of the mask and a color duplicate junction prepared with specific make-up and hair arrangement to provide camouflage.

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Nov 2, 2020 | Posted by in Oral and Maxillofacial Surgery | Comments Off on 6 Principles and techniques for facial allotransplantation
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