A swine model of reproducible timed induction of peripheral arterial shunt failure: Developing warning signs of imminent shunt failure

Temporary intravascular shunts are used to maintain perfusion in injured vessels, although failure can be unpredictable and lead to significant morbidity. The aim of the present study was to develop a dose- and timing-controlled swine model of intrinsic shunt failure to facilitate the development of a warning system for impending failure. Ten Yorkshire swine (weight, 56.6 ± 4.2 kg) underwent bilateral Argyle shunt (Cardinal Health, Dublin, OH) placement in the external iliac arteries, with proximal cannulation of the circumflex iliac arteries for infusion of thrombin. The thrombin infusion was randomized to the left or right side for 5000 vs 10,000 U/h. The 5000-U/h group required 2.1 times as long as the 10,000-U/h group to reach failure (mean, 21.8 minutes vs 46.4 minutes; P < .0001), as shown by a Kaplan-Meier survival analysis (log-rank P < .0001). However, the 5000-U/h group required the same total amount of thrombin (mean, 3752 ± 856 U; P = .57). Thus, time- and/or thrombin dose-controlled induction of shunt failure is technically feasible. Furthermore, in the final 15 minutes before failure, the flow was similar between the two groups (P >. 05), and the slope of the flow curve became more negative the closer the model was to failure. Overall, this model could be used to develop an alert system to predict for impending shunt failure or the need for intervention.