Arterial Blood Flow and Effects on Limb Tissue Perfusion During Endoshunting of the Common Iliac Artery in an Experimental Porcine Model

Objective

Temporary arterial shunting is an established method to prevent tissue ischaemia. Although less well established, shunting might also be achieved through endovascular and hybrid techniques, known as endoshunting. Endoshunting offers advantages, for example, enabling minimally invasive access and avoiding complete occlusion of the donor artery. In an ex vivo bench test, volume flow in various interconnected endoshunt systems has been tested previously. This study aimed to investigate the capacity of the best performing endoshunt system in vivo.

Methods

Six anaesthetised pigs had their common iliac arteries (CIAs) explored, with the left CIA serving as the experimental and the right CIA as the control. Mean arterial pressure, regional blood flow, endoshunt flow, and regional oxygen extraction and lactate production were recorded. Distal muscle perfusion was monitored using near infrared spectroscopy (NIRS). Each experiment involved baseline registration, cross clamping of the left CIA, a 120 minute endoshunt session, and restoration of native flow.

Results

During cross clamping, NIRS values on the experimental side reached the lowest measurable value. Following endoshunt activation, there were no NIRS value differences between the experimental and control extremities whereas the average arterial flow decreased in both the experimental (270–140 mL/min, p = .028) and control extremities (245–190 mL/min, p = .25), with a greater drop on the endoshunted side (48% vs. 22%, respectively). Lactate levels temporarily increased by 42% in the endoshunted limb on endoshunt activation but were normalised within an hour. Oxygen extraction remained constant at 55% on the control side but increased to 70% on the endoshunted side (p = .068).

Conclusion

In this animal model, a flow optimised endoshunt system appeared to provide sufficient blood flow and restored stable tissue perfusion. Although arterial flow was slightly lower and oxygen extraction slightly higher on the endoshunted side, the endoshunt seemed to deliver adequate perfusion to prevent significant ischaemia.