Characterisation of an experimental model of chronic lower limb ischaemia in the anaesthetised rat

Reperfusion injury is responsible for the failure of up to 15% of otherwise successful lower limb bypass procedures for critical limb ischaemia. It is also responsible for complications in myocardial revascularisation, organ transplantation and free flap transfers. The majority of experimental work investigating reperfusion injury has studied acute ischaemia in normal tissues which may reflect the situation in organ transplantation and free flap transfers, but in vascular reconstructive surgery the distal limb circulation is severely compromised prior to surgery. In the present study a model of chronic ischaemia in the rat hind limb has been produced by ligation of the left common iliac artery. Femoral artery blood pressure and flow measurements showed a mean reduction to 53% and 41% respectively when compared to the contralateral limb. These changes were maintained for up to nine weeks following ligation of the common iliac artery. Contrast arteriography was used to establish the anatomy of the collaterals and demonstrated that the femoral artery is an end artery. This technique provides a model of experimental chronic ischaemia which is stable for up to nine weeks and may be used to investigate the mechanisms involved in the reperfusion injury.