Transepidermal oxygen flux during arterial occlusion using ratiometric luminescence imaging

BACKGROUND: A physiological oxygen transport through a circulatory and microcirculatory system is essential for execution of cellular functions. Several pathological conditions e.g. infections, ischemia, cancer, diabetes, hypertension or chronic wounds show a change of oxygen distribution and oxygen tension in cellular microenvironment. Additionally complex operative procedures in order to reconstruct tissue defects require a reliable monitoring of microcirculation. OBJECTIVE: Target of this study was to evaluate skin oxygenation during an ischemia-reperfusion experiment using transepidermal oxygen flux imaging. METHODS: Twelve patients at the Department of Plastic and Reconstructive surgery of the University hospital of Regensburg underwent to elective hand operations. During the operation a tourniquet is standardly set on the upper arm to create ischemia in order to facilitate the operative procedure. Measurements were performed at the different time intervals: in rest, under ischemia and after reperfusion. RESULTS: The transepidermal oxygen flux increased during the ischemic condition compared to normal condition and decreased to a lower value during reperfusion (rest: 0.043 +/- 0.007, ischemia: 0.063 +/- 0.014, reperfusion: 0.030 +/- 0.028). CONCULSION: Transepidermal oxygen flux imaging by ratiometric luminescence imaging seems to be a reliable tool to assess skin oxygenation. However dynamic changes seem to be more informative than absolute thresholds. Further investigations are necessary to prove these promising results

New reconstruction for bone integration of non-vascularized autogenous bone graft with better bony union and revascularisation

Phalangeal defects are often seen after tumor resection, infections, and in complex open hand fractures. In many cases, reconstruction is difficult and amputation is performed to avoid prolonged rehabilitation that is often associated with a poor outcome. In these cases, the maintenance of length and function presents a reconstructive challenge. We reviewed 11 patients who underwent extensive phalangeal reconstruction with non-vascularized bone graft from the iliac crest using a key-in-slot-joint technique to provide acceptable function and bony union. In each case, non-vascularized bone graft with a length of 1.4-6.0 cm was used to reconstruct the phalanx. Follow-up ranged from 6 weeks to 5 months, and in all cases, there was bony union after 6 weeks. We evaluated range of motion, function, and as well pain and grip strength of the fingers. This case series suggests that a key-in-slot technique allows non-vascularized bone graft to be used in complex large phalangeal bone defects. Due to better bone contact, a sufficient perfusion and revascularisation of the non-vascularized bone graft can be achieved for a quicker and stable bony union. This method appears to be an alternative to amputation in selected cases with a satisfactory soft-tissue envelope

Allogeneic donor split skin grafts for treatment of refractory ulcers in cutaneous chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation—a retrospective analysis on seven patients

Refractory skin ulcers due to severe chronic graft-versus-host disease (cGVHD) remain to be associated with significant morbidity and mortality.We performed an allogeneic donor skin transplantation in seven adult patients after allogeneic hematopoietic stem cell transplantation for cGVHD-associated refractory skin ulcers. While four patients received a split skin graft (SSG), in one patient, a full thickness skin graft for two small refractory ulcers of the ankle was performed, and one patient received in vitro expanded donor keratinocyte grafts derived from hair roots of the original unrelated donor. In one additional patient, a large deep fascial defect of the lower leg was covered with an autologous greater omentum free graft before coverage with an allogeneic SSG. An additional patient was treated with an autologous scrotal skin graft for a refractory ulcer associated with deep sclerosis of cGVHD after unrelated donor transplantation.All skin grafts engrafted and resulted in permanent coverage of the grafted ulcers without any signs of immunological mediated damage. In the patient receiving in vitro expanded keratinocyte grafts, two localized ulcers were permanently covered by donor skin while this approach failed to cover extensive circular ulcers of the lower legs.Allogeneic donor skin grafts are a valuable treatment option in refractory ulcers due to cGVHD but are restricted mainly to related donors while keratinocyte grafts from unrelated donors remain experimental. In male patients lacking a related donor, autologous scrotal skin graft may be an alternative option