IJCS | Volume 31, Nº5, September / October 2018

467 Oliveira et al. Mortality and survival in aortic arch surgeries Int J Cardiovasc Sci. 2018;31(5)466-482 Original Article injury caused by involvement of cerebral vessels. This is more evident in case of acute events, due to the need for performing the surgery in appropriate time using adequate techniques for each case. Until the 1980’s, increased mortality rates related to surgical repair of aortic arch had been mainly associated with visceral ischemia, due to diversion of blood flow to false lumen (when femoral artery perfusion was performed), neurological complications secondary to brain ischemic lesions, and hemorrhagic complications, i.e., often uncontrolled, perioperative bleeding. 5,6 Symptomatic patients with aneurysm or dissection should be operated regardless of aneurysm size. In asymptomatic patients, aortic repair procedure is performed based on transverse diameter of the lumen, which is the main predictor of complications. 1 Today, the most common techniques for protection of the central nervous system in aortic arch surgery are: profound hypothermia with complete circulatory arrest (18 - 20ºC), 7 profound hypothermia with retrograde cerebral perfusion (through superior vena cava) 8 and antegrade selective cerebral perfusion with moderate hypothermia (25 - 28ºC). 9 This can be performed bilaterally, or through one carotid artery, brachiocephalic trunk or subclavian artery. Antegrade selective cerebral perfusion is the most effective method for brain protection, and the technique of choice by many surgeons. 9 Carreira et al. 5,6 described a new surgical strategy for aortic arch diseases with antegrade selective cerebral perfusion and preservation of part of patient’s original vessels, which allows the aortic arch repair without interruption of cerebral blood flow, and a shorter period of unilateral antegrade cerebral perfusion. One of themain criticisms of this approach, however, is that preservation of part of patient’s vascular tissue would increase the risk for recurrent aneurysmal disease or dissection. In the present study, we compared mortality rate between patients who had undergone surgery with partial preservation of aortic arch and supra-aortic vessels (group A) and those who had undergone conventional surgical procedures of aortic arch (group B), and survival curve of these patients in a mean follow-up of 3.22 years (1,178.27 days). The study was submitted to (Brazil online platform, May 2015) and approved by the Research Ethics Committee of Casa de Saúde São José (approval number 45613015300005664). Surgical strategies Surgical strategy of partial preservation of aortic arch and supra-aortic vessels (Group A) Surgical strategy of partial preservation of aortic arch and supra-aortic vessels described by Carreira et al. 5,6 was themain focus of this study. The surgery involves median sternotomy to get access to the heart and great vessels, followed by dissection of aorta and supra-aortic arteries. A curved clamp is placed on the brachiocephalic trunk and a 10 - 20mmvascular graft anastomosis ismade using a 5.0 polypropylene suture. An arterial cannula is inserted in the vascular graft next to the anastomosis. Venous cannulation depends on other associated procedures. Nasopharyngeal temperature is decreased to 22 - 25ºC by extracorporeal circulation (ECC) and maintained during surgery of aortic valve and confection of proximal anastomosis with tubular graft. A vascular clamp is placed on ascending aorta before retroperfusion of the coronary sinus. Then, a vascular clamp is positioned on the brachiocephalic trunk for a unilateral selective cerebral perfusion. Body perfusion is interrupted, and cerebral flow maintained at 300 - 500 mL/min through the right carotid artery for maintenance of right arterial pressure at 50 - 70 mmHg. Blood is diverted to the brachiocephalic trunk using a roller pump or a centrifugal pump for ECC at 20ºC - 25ºC. Aorta is cut following the interruption of systemic perfusion, leaving enough aortic tissue to isolate both brachiocephalic trunk and left carotid artery. Left subclavian artery is left close to the descending aorta. Isolation of brachiocephalic trunk and left carotid artery was achieved by closure of aortic “flap” with continuous 4.0 or 5.0 polypropylene suture. Then, brachiocephalic trunk clamping is released, and bilateral antegrade selective cerebral perfusion is started and maintained at 500 - 1,000 mL/min and 20 - 25ºC. Distal portion of aorta is cut and prepared for placement of Dacron tubular prosthesis. Left subclavian artery is positioned next to distal anastomosis so that it can be ligated in case of significant lesion, and aortic endoprosthesis can be implanted by antegrade approach if necessary. After completion of distal anastomosis with 4.0 polypropylene suture, an arterial cannula is inserted into aortic prosthesis and clamped for restauration of body perfusion by blood infusion at 25ºC. Rewarming (3ºC every 10 minutes) is performed during this period.