LAUSR

The advent of frozen elephant trunk (FET) has revolutionized aortic arch repair and also further approaches to pathologies involving descending aorta, providing a single‐stage treatment of both arch and descending aorta. A large body of evidence published previously reported short‐ and long‐term outcomes of FET. However, a potential shortcoming of this technique is the necessity of a complex arch replacement which is accompanied by adverse events, mainly neurologic and renal failure due to circulatory arrest. Although moderate hypothermic circulatory arrest (MHCA) with selective cerebral perfusion offers an equivalent visceral and cerebral protection during arch procedures compared with deep hypothermic circulatory arrest (DHCA), an immense attempt has been made to reduce MHCA time, achieving a lower incidence of visceral ischemic complications as well as renal impairment after FET. At the same time, with the introduction of the newer generations of FET, other series published results of modifications in FET procedure to address the unsolved problem of circulatory arrest time. With newer FET generations, approaching distal anastomosis has been targeted along with well‐established, safer surgical technique adjustment (i.e., proximalization of distal anastomosis from Zone 3 to Zone 2 or even to Zone 1 or 0) Aortic occlusion balloons, also an adjunct, are being utilized to achieve lower circulatory arrest time with earlier restoration of lower body perfusion before completing distal anastomosis. Nevertheless, newer generations of FET devices coupled with increasingly FET experiences prevent the popularity of aortic balloon occlusion as anticipated. We read with great interest Piperata et al. article on (Evaluation of the “release and perfuse technique” for aortic arch surgery). They reported their result using a modified technique named “release and perfuse technique (RPT).” The primary rationale behind their proposed approach was to minimize lower body circulatory arrest time. The authors described their technique during aortic arch replacement under MHCA plus selective antagrade cerebral perfusion (SACP). They also cited previous attempts published to reduce lower body circulatory arrest time as mentioned above. This adjunct procedure seems to be more valuable in stringent and particular situations with minimum exposure of Zone 2 or Zone 3, which the surgeon finds hardship with, such as re‐do operations or huge aneurysmal sac repair, as well as aortic dissections in emergency settings. A recent meta‐analysis conducted by Cao et al. observed a lower incidence of renal failure and need for renal replacement therapy in MHCA compared to DHCA when the lower body circulatory arrest time was less than 30min but a similar pooled incidence of this complication in both groups for longer than 30min. This 30‐min period for an aortic surgeon adequately allows insertion of FET conduit along with safe and hemostatic anastomosis of its collar, generally. Hence, reducing the lower body circulatory arrest time by performing RPT in the expense of potential backflow bleeding around a stented portion of FET and as the result, some difficulty in suturing the FET's collar, is not the optimal choice. Visceral organ protection is also well achieved by lowering core body temperature because of reduced metabolism rate and oxygen demand along with catching of more safe circulatory arrest time.