Radionuclide methodology for the assessment of the microcirculation in island pedicle flaps in a sheep model

Effect of Ridogrel, a thromboxane receptor blocker and synthesis inhibitor on plasma and red blood cell flow in an arterial skin flap in sheep

This study evaluates the effect of the new combined thromboxane synthesis inhibitor and receptor blocker, ridogrel, on the circulation of arterial skin flaps in sheep. Sixteen flaps, 8 controls and 8 treated with 5 mg/kg ridogrel, were investigated using 111Indium chloride labelled plasma and 99mTc labelled red blood cells (RBCs). Dynamic imaging was performed after a bolus injection using a GE 400 AT gamma camera. For each flap quantitative analysis of plasma and RBC flow was based on time activity curves obtained from 12 regions of interest. Analysis of flow data was made immediately after flap elevation and three hours later. Both plasma and RBC flows declined after 3 hours. Treatment with ridogrel significantly prevented deterioration of perfusion by increasing plasma and RBC flow mostly in the distal, ischaemic regions of the flap where stasis was evident in the control flaps.