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Dr Chaer (Pittsburgh, Pa). You have reported on 72 patients who underwent TEVAR after prior AAA repair. As expected, the incidence of cord ischemia was quite high, up to 12%, and was permanent in up to 7% of your patients. The known risk factors for cord ischemia did not really bear out in this particular analysis such as the status of the left subclavian artery, the hypogastric artery status, as well as hypotension intra-operatively, and pre-op CSF drainage. Only pre-op renal failure was a predictor of cord ischemia. I have the following questions:

And my last question is, have you changed your practice based on the findings of your study? Do you worry about collateral flow from the hypogastric or the left subclavian? And do you routinely now place spinal drains preoperatively? Do you perform any adjunctive maneuvers in renal failure patients to try to prevent cord ischemia?

Dr Schlosser. Cerebrospinal fluid drainage was started immediately in patients with symptoms of spinal cord ischemia after the onset of symptoms if this was not yet started. Cerebrospinal fluid drainage was subsequently continued for a couple of days. Blood pressure was monitored strictly in these patients to prevent episodes of hypotension. This strategy resulted in complete disappearance of symptoms in 4 of 9 patients. Symptoms also improved considerably in the other 5 patients, but some of their symptoms, unfortunately, remained after treatment.

It is well established in literature that paraplegia or paraparesis after thoracic aortic aneurysm repair can have a delayed onset. The time period between TEVAR and subsequent symptoms of SCI in our study did not surprise us because they are not considerably different than average.

We have changed our practice considerably on the basis of our results. In the first place, the threshold for surgery should be higher in patients with prior AAA repair from our point of view, especially in patients with a history of both renal failure and AAA repair. If the TEVAR is still indicated, due to a large aneurysm and relative high rupture risk, we prevent coverage of the left subclavian artery in these patients during TEVAR. A bypass procedure can be performed if the left subclavian artery needs to be covered. We also prevent coverage of the hypogastric arteries as much as possible in these patients. Cerebrospinal fluid drainage is started preoperatively in all patients with prior AAA repair and continued for several days after the procedure. And last but not least, blood pressure is monitored as strict as possible to prevent hypotension.