Surgical Treatment Of Aortic Arch Diseases Under Deep Hypothermic Circulatory Arrest And Selective Cerebral Perfusion

Object: To summarize the methods and the experiences of surgical treatment of aortic arch diseases with four branches aortic graft under deep hypothermia circulatory arrest (DHCA) and antegrade selective cerebral perfusion (ASCP).Method: From November 2004 to December 2007, six patients with DeBakey type I aortic dissections or aneurysms involving the aortic arch received total aortic arch replacement by four branches aortic graft under the condition of general anesthesia,deep hypothermic circulatory arrest and selective cerebral perfusion. Those cases were collected by Cardio-Vascular Center of the Second Affiliated Hospital Medical College of JiLin University. The six patients, including tow men and four women, with an age range of 35~60 years, with a weight range of 49~85kg, with a course range of 2 days to 30 months. One case was aortic arch aneurysm, five cases were aortic arch dissecting aneurysm (DeBakey type I).The five cases contained one patient of Marfan syndrome and four patients of Aortic insufficiency. Four patients had history of hypertension. All patients had surgical treatment. In the course of surgery, we used a kind of general anesthesia-intravenous anesthesia combined inhalation anesthesia. The anesthetist judged the anesthesia depth and adjust the protocol accordingly by his experiences. The patients were induced with midazolam, fentanyl, propofol and vecuronium. Anesthesia were maintained with propofol in micro pump and accompanied with Isoflurane, other ancillary drugs were used according to the circumstances. All operations were carried out under DHCA and ASCP, and four branches aortic graft were used to replace the aortic arch. We operated according to different lesions. The Bentall procedure and elephant trunk technique were undertaken in different patients. We made the records as follows: operation time, myocardial clamping time, deep hypothermic circulatory arrest time, ASCP time, CPB time, blood transfusion, chest drainage, the time of beginning to awaken, ventilator-assisted ventilation time, ICU time, hospitalization time and so on. As all measured and calculated data described were presented as mean values with standard deviations (±s). The clinical data were retrospectively analyzed and the experience was summarized.Results: The time of operation was 6.0-12.8h, with a mean of (9.3±2.9)h, the time of cardiac muscle interdiction was 80-299min, with a mean of (201.3±84.4)min, the time of deep hypothermic circulatory arrest was 22-64min, with a mean of (49.5±15.9)min, the time of ASCP was 22-67min, with a mean of (49.3±17.0)min, the time of CPB was 166-377min, with a mean of (261.5±88.3)min, the blood transfusion was 4075-1799ml, with a mean of (4075±1798)ml, the chest drainage was 415-3855ml, with a mean of (1746±1155)ml, all patients began to awaken within five hours of postoperation. the time of assisted ventilation was 22.3-144h, with a mean of (66±51)h, the time in ICU was 4-13d, with a mean of (6.5±3.6)d, the time of hospitalization was 14-26d, with a mean of (19.0±4.6)d. Five patients′hearts were automatic beating, one used a temporary pacemaker. Total 6 patients recovered from the great vessel diseases smoothly without severe cerebral and other systematic complicationsConclusion: Deep hypothermia circulatory arrest (DHCA) is the simplest method of brain protection in the replacement of total aortic arch, and is one of the earliest recognized skill used in the surgical treatment of aortic arch diseases, however, it has the shortcomings: its permission time is limited. As a result DHCA only can be used in the simple surgery, the time of which is short relatively, DHCA needs the process containing cooling and rewarming steps. We usually consume a lot of time in the steps. Naturally DHCA prolongs the CPB time, it can damage coagulation function and lead to the lesion of pulmonary system. The mentioned factors restrict its application in the surgical treatment of aortic arch diseases. So we should avoid or reduce its application as possible as we can, especially in the complex diseases, such as complicated congenital heart diseases, large thoracic aortic aneurysms, aortic dissection involved aortic arch, or it is considered to be used by combining with other celebral perfusion methods. Antegrade selective celebral perfusion(ASCP) is a celebral perfusion method which is close to physiological state, its benefit is quite obvious. The most obvious advantage of the technology is that brain can get perfusive blood during circulatory arrest, the brain tissue is not ischemia. The time of circulatory arrest is not restricted strictly, so that operators can have enough time in the operation of surgical treatment of aortic arch diseases. The skill does not need deep hypothermia, it can shorten the process of cooling and rewarming, it also can avoid many complications caused by circulatory arrest such as coagulation dysfunction. Four branches aortic graft is a kind of new artificial vascular substitute developed in recent years. Four branches aortic graft is used in total aortic arch replacement. Its biggest advantage is to shorten the time of deep hypothermia circulatory arrest. The graft makes surgery skill more and more flexible, it can reduce many injuries caused by surgery. Especially it can avoid complications of brain to the utmost extent. According to our cases, we can draw the conclusion that the application of DHCA and ASCP provides a safer condition for aortic arch replacement and is a safe and effective method of cerebral protection during circulation arrest, four branches aortic graft may shorten the time of DHCA and simplify the procedure of operation.