Cerebral embolization during endovascular infrarenal, juxtarenal, and suprarenal aortic aneurysm repair, high-risk maneuvers, and associated neurologic outcomes

Background: Risk factors for postoperative cognitive decline after noncardiac surgery are multifactorial and poorly understood. Evidence suggests that perioperative microembolic damage to the brain on movement of wires and catheters during endovascular aortic procedures may play an important role. Endovascular aortic aneurysm repair requires invasive manipulation of wires and cannulas within the aorta, but research into cerebral emboli during aortic aneurysm repair and cognitive or neurologic injury is scarce and limited to thoracic aneurysms. This study prospectively studied embolic phenomena detected in the middle cerebral artery during infrarenal, juxtarenal, and thoracic endovascular aortic repair (TEVAR) and investigated links to delirium, stroke, and postoperative cognitive decline. Methods: There were 60 patients who received continuous left-sided perioperative transcranial Doppler monitoring during endovascular aortic aneurysm repair (bifurcated graft for infrarenal aneurysm, n = 18; endovascular aneurysm sealing graft, n = 16; endovascular aneurysm sealing and renal "chimney" stent, n = 17; and thoracic aneurysm, n = 3). The procedure was time stamped for events such as stiff wire insertion and graft deployment. A battery of cognitive tests designed to test several cognitive domains were performed preoperatively and at 90 days postoperatively. Results: TEVAR and chimney grafts demonstrated significantly greater numbers of total procedural emboli compared with standard bifurcated grafts (mean emboli, 36.2 and 13.39, respectively; bifurcated graft, 5.81; P<.05). The highest risk maneuvers were guidewire and pigtail catheter insertion. This was the case for all procedures including infrarenal aneurysm repair. A higher perioperative embolic load was associated with medium-term cognitive decline in list recall but not with incidence of delirium or stroke. Risk of cognitive decline did not relate to procedure type. Antiplatelet use failed to demonstrate a protective effect. Conclusions: Patients are at risk of cerebral emboli during several types of endovascular aortic surgery, although TEVAR remains the highest risk procedure. As yet, there are no validated protective measures available to prevent cerebral emboli and their associated risks of clinical and subclinical neurologic injury.