Evaluation of a continuous systemic infusion of iloprost, a stable PGI-2 analog, on the survival of experimental skin flaps

Remodelling of the superficial vascular network of skin flaps in rats, following a vasodilatory cream application, before elevation

Flap necrosis on random pattern skin flaps continues to be a challenge. In this study, we evaluated whether topical application of a vasodilator substance (the prostaglandin PGI₂ analogue, Iloprost^®, in cream form) as pre-treatment, would increase blood flow and improve flap viability. Wistar rats randomly allocated into four groups with 7 rats per group and two flaps 4cm × 2cm in the same rat i.e. 56 flaps were developed. Flaps on the wright side received pre-treatment with Cream in different drug concentrations, 2.5μgr/gr, 5 μgr/gr, and 10μgr/gr and 20 μgr/gr containing the active factor Iloprost^®® ZK 36,374(M. W 360.5) prepared with white petrolatum as a base. Flaps on the left side received placebo cream (white petrolatum). After 10 days of flap pre-treatment, evaluation of blood flow by laser Doppler flowmetry (LDF) were recorded, then flap elevation and re suturing back were performed. After 7 days we estimated flap viability on digital imaging and the percentages of flap survival estimated. Means and standard deviations were used to describe blood flow measurements and survival percentages. The significance was set at 0.05 in all cases and the analysis were carried out with the use of the SPSS v23.0. Furthermore, we performed dynamic analyses of circulation using the radioisotope 99mTc which confirmed hyperaemia of the treated areas relative to that observed in control areas. These findings demonstrated that pretreatment of skin flaps with Iloprost^® cream for 10 days prior to elevation increased blood flow in the flap and improved their overall survival rate.

Ischemia/reperfusion injury in microvascular surgery

Ischemia/reperfusion injury is often the final and irreversible factor causing flap failure in microvascular surgery for head and neck defects. This paper begins with a detailed review of flap physiology and ischemia/reperfusion injury at the cellular level. Subsequently, the pharmacotherapeutic agents used clinically and experimentally to avoid or reverse ischemia/reperfusion injury are discussed. The goal of this review is to provide a framework for understanding the expanding body of literature relevant to ischemia/reperfusion injury in microvascular surgery.