Machine Perfusion Enables 24-h Preservation of Vascularized Composite Allografts in a Swine Model of Allotransplantation.

The current gold standard for preserving vascularized composite allografts (VCA) is 4°C static cold storage (SCS), albeit muscle vulnerability to ischemia can be described as early as after 2 h of SCS. Alternatively, machine perfusion (MP) is growing in the world of organ preservation. Herein, we investigated the outcomes of oxygenated acellular subnormothermic machine perfusion (SNMP) for 24-h VCA preservation before allotransplantation in a swine model. Six partial hindlimbs were procured on adult pigs and preserved ex vivo for 24 h with either SNMP (n = 3) or SCS (n = 3) before heterotopic allotransplantation. Recipient animals received immunosuppression and were followed up for 14 days. Clinical monitoring was carried out twice daily, and graft biopsies and blood samples were regularly collected. Two blinded pathologists assessed skin and muscle samples. Overall survival was higher in the SNMP group. Early euthanasia of 2 animals in the SCS group was linked to significant graft degeneration. Analyses of the grafts showed massive muscle degeneration in the SCS group and a normal aspect in the SNMP group 2 weeks after allotransplantation. Therefore, this 24-h SNMP protocol using a modified Steen solution generated better clinical and histological outcomes in allotransplantation when compared to time-matched SCS.

A Reliable Porcine Fascio-Cutaneous Flap Model for Vascularized Composite Allografts Bioengineering Studies.

Vascularized Composite Allografts (VCA) such as hand, face, or penile transplant represents the cutting-edge treatment for devastating skin defects, failed by the first steps of the reconstructive ladder. Despite promising aesthetic and functional outcomes, the main limiting factor remains the need for a drastically applied lifelong immunosuppression and its well-known medical risks, preventing broader indications. Therefore, lifting the immune barrier in VCA is essential to tip the ethical scale and improve patients' quality of life using the most advanced surgical techniques. De novo creation of a patient-specific graft is the upcoming breakthrough in reconstructive transplantation. Using tissue engineering techniques, VCAs can be freed of donor cells and customized for the recipient through perfusion-decellularization-recellularization. To develop these new technologies, a large-scale animal VCA model is necessary. Hence, swine fascio-cutaneous flaps, composed of skin, fat, fascia, and vessels, represent an ideal model for preliminary studies in VCA. Nevertheless, most VCA models described in the literature include muscle and bone. This work reports a reliable and reproducible technique for saphenous fascio-cutaneous flap harvest in swine, a practical tool for various research fields, especially vascularized composite tissue engineering.

Reconstruction of post-burn anterior neck contractures using a butterfly design free anterolateral thigh perforator flap.

Anterior neck burns represent a major reconstructive challenge due to severe sequalae including restriction in movement and poor aesthetic outcomes. Common treatment options include skin grafting with/without dermal matrices, and loco-regional and distant free flap transfers with/without prior tissue expansion. Such variation in technique is largely influenced by the extent of burn injury requiring resurfacing. In order to optimize like-for-like reconstruction of the anterior neck, use of wide, thin and long flaps such as the anterolateral thigh (ALT) perforator flap have been reported with promising results. Of note, some patients have a tendency towards severe scar contractures, which may be contributed by the greater extent of inflammation during wound healing. We report our experience at 4 years' follow-up after secondary reconstruction of severe, anterior neck burn contractures in two patients by harvesting the ALT flap with a butterfly design. This technique provides adequate wound resurfacing of the burned neck and surrounding areas, and provides good neck extensibility by addressing both anterior and lateral aspects of the scar defect simultaneously. Such a flap design reduces tension on wound edges and thus, the risk of contracture recurrence in what remains a particularly challenging type of burn reconstruction.