Commentary: Preoperative cerebral malperfusion in aortic dissection: Symptoms may be deceivers.

Michele Di Mauro, MD, PhD, MSc, and Antonio M. Calafiore, MD

The cases do not trace definitive conclusions, but open the door a crack and see a chance to improve the outcomes of patients with aortic dissection by assessing cerebral perfusion with CT perfusion.

See Article page 190.

Neurological injuries are a noteworthy issue in aortic dissection because the frequency of both preoperative and postoperative cerebral events is high, with negative influence on prognosis. In particular, preoperative cerebral malperfusion is estimated at 3.3% and 21%.2, 3, 4, 5

Frequently, patients undergo emergency surgery and, despite the lack of clear evidence of cerebral malperfusion, they may develop neurological symptoms during the postoperative course. The opposite is also true: Even less frequently, patients with clear signs of cerebral malperfusion do not develop permanent neurological deficits postoperatively.

We should wonder about the reasons underlying these different behaviors, and the answer can be only that we don't know really know how much malperfusion has already impaired neurological functions at the time of surgery. Symptoms may be deceivers, and whereas computed tomography perfusion (CTP) is an imaging technique enabling evaluation of both rapid qualitative and quantitative cerebral perfusion and providing some important information on parameters such as cerebral blood flow and blood volume as well as mean transit time. Different imaging modalities have been used to assess cerebral perfusion, such as magnetic resonance perfusion, xenon CT, positron emission tomography, and single photon emission computed tomography. However, CTP seems to be the easiest and fastest imaging approach to obtain information about cerebral perfusion before an emergent surgical procedure such as the one for aortic dissection and this information can be useful for a surgeon to assess the prognosis and to adopt any surgical and medical procedures aimed at improving brain protection. The 2 cases reported by Inoue and colleagues are not sufficient to trace definitive conclusions but open the door a crack, and let us glimpse the chance to improve the outcomes of patients with aortic dissection, by preoperatively assessing cerebral perfusion.