Endovascular shunting techniques in vascular surgery

Abstract

Abstract

Background: Acute tissue ischaemia can lead to significant tissue damage and, in severe cases, permanent loss of organ or limb function. Temporary arterial shunting is an established technique to mitigate ischaemic effects. This can also be achieved using endovascular or hybrid methods, so called endoshunting. Aims: This thesis aimed to evaluate the efficacy and feasibility of endovascular shunting.

Materials and Methods: The endoshunt technique was assessed through a series of experimental studies. Initially, an in vitro bench test was conducted to optimise system components and volume flow rates. Two subsequent animal studies evaluated endoshunting for functional outcomes and tissue perfusion when applied to extremities and renal circulation. Finally, a retrospective clinical study examined patients undergoing complex open aortic reconstructions, with a subgroup that received endoshunting to the renal artery.

Results: The efficacy of endoshunting was highly dependent on the choice of system components. A flow-optimised endoshunt successfully restored extremity tissue perfusion in a porcine model. In renal applications, endoshunting facilitated rapid recovery of perfusion and urine production when used during prolonged periods of renal artery cross-clamping, indicating its potential utility in renal artery interventions. Clinical analysis of complex open abdominal aortic repairs demonstrated favourable outcomes when performed by a specialised surgical team, with results comparable to those of elective infrarenal surgeries.

Conclusion: Endoshunting achieved volume flow rates comparable to conventional shunting techniques over both short and long distances. The technique showed significant promise in mitigating extremity ischaemia and protecting renal function during complex aortic surgeries requiring suprarenal aortic clamping.