Brief ex vivo perfusion with heparinized and/or citrated whole blood enhances tolerance of free muscle flaps to prolonged ischemia

Abstract

This study investigated the use of heparinized and/or citrated whole blood as a perfusate for enhancing muscle tolerance to warm ischemia. Unilateral cutaneous trunci muscle flaps were harvested from Sprague-Dawley rats and stored for 10 hr at 22-24 degrees C prior to transplantation to the groin. One group served as a non-perfused control. In three experimental groups, the flaps were hand-perfused ex vivo with 1.0 ml of heparinized, citrated, or heparinized and citrated autogenous whole blood at physiological pressures. Perfusion was administered over a 10-min period 5 hr into the ischemic period. Flaps were revascularized on the femoral vessels and then harvested 48 hr following revascularization. Tissue injury was assessed by calculation of flap weight change (indicator of tissue edema), histochemical evaluation of muscle dehydrogenase activity (nitroblue tetrazolium assay), and light microscopy. All perfused groups had significantly higher muscle dehydrogenase activity compared with non-perfused controls (P < 0.005). Perfusion with combined heparin-citrated blood was significantly more protective than perfusion with either anticoagulant alone (P < 0.025). The only statistically significant reduction in percent flap edema was seen in the combined heparin-citrate perfusion of flaps compared with nonperfused controls (P < 0.05). Histologic evaluation confirmed a reduction in tissue edema in the perfused flaps. We conclude that mid-ischemic perfusion with heparinized and/or citrated blood limits the deleterious effects of extended warm ischemia.

Ischaemia‐related cell damage in extracorporeal preserved tissue – new findings with a novel perfusion model

“…However, complications and even complete failure because of partial or complete necrosis of the transplanted tissue may occur in 5% of all cases . Tissue damage caused by prolonged ischaemia after harvesting the flap is still one of the limiting factors . At this time, the standard procedure in reconstructive surgery for flap preservation is cold storage, often in addition with a singular flush of the tissue with a saline solution.…”

“…At this time, the standard procedure in reconstructive surgery for flap preservation is cold storage, often in addition with a singular flush of the tissue with a saline solution. In the past, numerous studies have been set‐up to learn more about causes of ischaemia‐related tissue damage and optimizing conservation protocols . Even though most of these studies revealed encouraging results, at present none of them essentially changed the standard procedure in daily clinical routine.…”

Examination of the protective effects of heparin and recombinant tissue plasminogen activator (rtPA) in compromised adipocutaneous free flaps in the rat model using intravital video microscopy

“…The rinsing of the flap tissue with heparin solution as performed in this study forms an inner anticoagulant surface. It is known that heparin influences rheological properties of blood and that it protects free flaps from ischemia/reperfusion injury [9,11,13,19,24,28]. Former experiments with neurovascular epigastric skin island flaps in the rat model demonstrate that systemic treatment with 300 I.U./kg of heparin increases the tissue tolerance to venous occlusion and significantly improves flap survival [29].…”

Addition of tanshinone IIA to UW solution decreases skeletal muscle ischemia-reperfusion injury1

“…University of Wisconsin (UW) solution has been widely used in the setting of liver, pancreas, and kidney transplantation. However, it is arguable whether or not UW solution is beneficial for preserving skeletal muscle [6][7][8][9] .…”