Dr. Iwata and colleagues recently reported a case series using a single centrifugal pump and four separate arterial lines for antegrade selective cerebral perfusion (ASCP) and systemic circulation for aortic arch construction (1). They should be congratulated for excellent clinical results and rational perfusion design for ASCP during deep hyperthermia circulatory arrest (DHCA).Currently, DHCA with ASCP is widely accepted as a routine means to protect the central nervous system during aortic arch reconstruction; however, the risks of central neurologic complications related to DHCA and extensive ASCP times also remain a substantial burden in aortic arch construction. As a result, the best way to protect the brain, spinal cord, and major organs is to shorten the period of ASCP as much as possible to avoid malperfusion during DHCA. ASCP has become recognized as an important way for arch replacement and can be performed through several different means: right axillary artery cannulation with balloon catheter in the left common carotid artery (2), direct balloon catheter perfusion of the innominate and left common carotid arteries (3-7), unilateral cerebral perfusion through the right axillary artery (8) or the right brachial artery (9), and even direct, bilateral cannulation of the carotid arteries outside the thorax (10).In this particular investigation, the authors used one centrifugal pump and four separate arterial lines for ASCP and system perfusion with four different cannular sites. We would like to compare their ASCP method with ours (one pump with two separate arterial lines), and discuss possible optimal ASCP strategy during aortic arch surgery. First, the authors maintained ASCP flow rate with 10 mL/ min/kg to perfuse the brain bilaterally via three cannulae using the brachiocephalic artery, left common carotid artery, and left subclavian artery, respectively. Compared with bilateral cerebral perfusion (BCP), unilateral cerebral perfusion (UCP) through the axillary or right subclavian artery has been used in our hospital since 1996; we have used BCP only for patients suspected of having a nonintegrated circle of Willis (11). Although the authors' method in this study using three perfusion cannulae in the limited space of the mediastinum may obscure the operative field during arch replacement, the distribution of blood flow for the brain is more physiological. In our current study (unpublished data), we did not find any difference in the distribution of blood flow between UCP and BCP under DHCA using a transcranial Doppler for patients with an integrated circle of Willis during aortic arch reconstruction and stented elephant trunk procedure; however, malperfusion was observed once the system perfusion was initiated via one graft of the four-branched graft, and overperfusion was found in the brain using a transcranial Doppler with UCP. In their article, the authors also measured the flows with an ultrasound flow meter, and after recovering the full system flow, and there was no malperfusion observed. A possi...