Strategies to prevent TEVAR-related spinal cord ischemia

Abstract

Spinal cord ischemia remains the Achilles' heel of thoracic and thoracoabdominal diseases management. Great improvements in morbidity and mortality have been obtained with the endovascular approach TEVAR (Thoracic Endovascular Aortic Repair) but this devastating complication continues to severely affect the quality of life, even if the primary success of the procedure - dissection/aneurysm exclusion - has been achieved. Several strategies to deal with this complication have been published in the literature over the time. Knowledge and technology have been evolving from identification of the risk factors associated with spinal cord ischemia, including lessons learned from open surgery, and from developments in the collateral network concept for spinal cord perfusion. In this comprehensive review, the authors cover several topics from the traditional measures comprising haemodynamic control, cerebrospinal drainage and neuroprotective drugs, to the staged-procedures approach, the emerging MISACE (minimally invasive selective segmental artery coil-embolization) and innovative neurologic monitoring such as NIRS (near-infrared spectroscopy) of the collateral network.

Collateral Circulation in Spinal Cord Injury: A Comprehensive Review

“…This is consistent vascular adaptation in increased quantity and density of arterioles and a change of arrangement, parallel to the spinal cord (collateral maturation) to permit flow from the subclavian arteries rostrally and the hypogastric arteries caudally. 9,11,15,16 Furthermore, pig models recovered quickly due to this collateral vascular supply network. 15 Among the 6000 segmental arteries' ligation, there were no cases of paraplegia, so it is inferable that the ischemic event did not take place.…”

“…12,13 Different studies in animals showed that the interruption of the flow of all segments to the spinal cord did not produce hypoxic intrathecal acidosis or spinal dysfunction, which remained until the subclavian or middle sacral artery clamping was done. 11 There is a specific case in which the collateral pathway lacks vascular resistance and the main source decreases its flow, which is called steal; for example, in the event of an aortic cross-clamp, drug-induced arteriovenous shunts, or in the case of bleeding from the intercostal artery in an open excluded aortic segment, conditions demonstrated by experimentation. 9,14 A postmortem study in humans demonstrated the permeability of collateral pathways to the spinal cord by injection of dye.…”

Spinal Cord Protection During Open and Endovascular Aortic Repair: State of the Art

“…Another approach is to suspend drainage postoperatively as soon as the patient is able to demonstrate normal force in the lower limbs, keeping MAP at 90-100 mmHg. If the patient develops symptoms, a neurological evaluation is recommended followed by haemodynamic optimization and CSF drainage increase (if it has been decreased in the meantime) [46].…”

Epidural Corticosteroids, Lumbar Spinal Drainage, and Selective Hemodynamic Control for the Prevention of Spinal Cord Ischemia in Thoracoabdominal Endovascular Aortic Repair: A New Clinical Protocol

“…Immediate, proactive, and aggressive strategies may be able to successfully treat SCI as there may be an early window of time in which certain forms of SCI may be reversible [9], but it should be better prevented. A variety of protective strategies have been reported, such as hemodynamic control, drainage of cerebrospinal fluid (CSF), and neuroprotective pharmacotherapeutic agents [6,22,24].…”