The Role of Endovascular Stents in an Experimental Model of Traumatic Arterial Occlusion – the Temporary Endo-Shunt
Background.We aimed to evaluate patency following the deployment of a bare-metal (BMS) or covered stent (CS) across a traumatic occlusive arterial lesion and to estimate the feasibility of urgent stent placement for temporary endovascular shunting.
Methods. Fifteen sheep (25-45 kg) underwent laparoscopic creation of a left external iliac artery (EIA) thrombosis by means of repeated clamping. Animals were then randomized into one of three groups: no-treatment (control group), a BMS group or CS group. Animals were followed up for 30 days with no anticoagulants or anti-platelet drugs administered postoperatively. Doppler ultrasound, computed tomography angiography (CTA), and digital subtraction angiography (DSA) were used to evaluate EIA patency.
Results.Stent implantation resulted in the restoration of in-line flow through the EIA in all cases. The peak systolic velocity (PSV) in the injured limb increased from 10 (0–16) to 31 (28–37) cm/sec in the BMS group (p<0.0001) and from 15 (7–18) to 24 (21–29) cm/sec in the CS group (p=0.043) immediately after stent deployment (both p=0.001 compared to the control group). There was no difference in the PSV between the groups at post-injury day 3, and thereafter. Day-14 CTA and day-30 DSA demonstrated only one patent stent in each study group.
Conclusions.Stent (BMS or CS) implantation restores arterial patency of a traumatic occlusive lesion for a period of less than three days in our ovine model. While acute recanalization of the injury with stent implantation may be used for temporary endovascular shunting, long-term patency remains a problem.