gms | German Medical Science

Introduction: Free tissue transfer forms a core modality in the plastics surgeon’s approach to the management of tissue defect cover and reconstruction. In considering muscle-based flaps, with their comparatively high ischaemic susceptibility, the question arose of a means of extracorporal preservation, indeed over prolonged periods, without impacting on their viability.

Material and methods: 33 porcine rectus abdominis muscle flaps were raised and divided into seven study groups. Group I, formed the untreated control group. Group II flaps were continuously perfused with Bretschneider solution via a closed circuit system. Group III flaps once raised, were immediately flushed once with 10mls of Bretscheider solution. Groups IV and V were perfused with ‘room-air’ oxygenated Jonosteril^® and Bretschneider solutions respectively. Group VI flaps like Group III, were flushed once when raised, but by 10mls of University of Wisconsin Solution (UWS) whilst Group VII was thoroughly perfused with UWS.

Flap Tissue biopsies were taken at 0, 15, 30 and 60 minutes post treatment initiation. Caspase-3 and HIF-1α antibody analysis was performed as markers of apoptosis and hypoxia. Blood partial pressure oxygen saturation measurements were taken of the perfusion fluid within the aterial and venous circuit limbs.

Results: Caspase-3 expression at 60 minutes was statistically significantly lower in Groups II to VII compared with the control group. This was reflected by statistically significantly lower HIF-1α expression in groups II, IV-VII. Oxygenation of the perfusion fluid, Group IV and V, prevented venous oxygen saturation partial pressure values dropping to zero.

Conclusion: Extracorporal muscle flap tissue perfusion and oxygenation are possible using a perfusion system. In so doing, within our porcine model, expression of apoptosis and hypoxia markers could be reduced. Additionally, room-air oxygenation of the perfusion fluid appears to stabilise venous oxygen partial pressure.