Measures to tackle spinal cord ischemia in TEVAR

Measures to tackle spinal cord ischemia in TEVAR

Spinal cord ischemia manifesting as paraplegia is one of the important complications of TEVAR (Thoracic endovascular aortic repair). Avoiding blockage of left subclavian which gives branches which eventually supply the spinal cord is a preventive option in elective setting. In cases in which left subclavian needs to be over stented,  a hybrid procedure with a surgical graft to the vessel likely to be blocked being placed before TEVAR is an option. Pre procedure drainage of CSF (cerebrospinal fluid) can be useful as it has been proven useful in aortic surgery for protection of spinal cord. CSF drainage is an immediate option for reversal of paraplegia if it does occur unfortunately. Other option is to raise the blood pressure with mean around 90 mm Hg. This should be maintained for 24 to 48 hours. Episodes of hypotension should be prevented as far as possible to prevent spinal cord ischemia. The concept is that hypotension and increase in CSF pressure both compromises the spinal cord perfusion pressure [1]. Staging of procedures has been developed to reinforce collateral blood flow to the spinal cord when there is a high risk of spinal cord ischemia. Classical staged procedure is two step repair with delayed implantation of aortic stent grafts. Other preventive methods are leaving an endoleak for short term salvage of segmental artery perfusion, perfusion branches, delayed bridging stents and open branch technique. Perfusion branches are custom made and provide temporary endoleak to perfuse the aneurysmal sac and the segmental arteries. These are closed one to two weeks later.

Reference

1. Heidemann F, Tsilimparis N, Rohlffs F, Debus ES, Larena-Avellaneda A, Wipper S, Kölbel T. Staged procedures for prevention of spinal cord ischemia in endovascular aortic surgery. Gefasschirurgie. 2018;23(Suppl 2):39-45.