The fact that the surgical management of acute type B dissection of aorta is not superior to the medical approach limits the number of surgical cases and prevents the acquisition of adequate experience. In our hospital, two cases of aortic replacement were performed because of the persistence of the pain despite medical management in these patients with acute type B aortic dissection. In two other cases cardiopulmonary bypass with mild hypothermic distal perfusion at 34°C were applied. There were no pre or postoperative complications. The focus of disputes on the surgery of thoracic aorta is about the damage of the vital organs caused by ischemia reperfusion during surgery, primarily that of the spinal cord. In order to prevent this damage, especially during cross-clamping that lasts more than 40 minutes, it is suggested that left atrio-femoral bypass or distal perfusion with CPB be performed. The disadvantages of CPB compared to left atrio-femoral bypass are bleeding problems due to application of oxygenator and heparinization. On the other hand, the advantages are better gas exchange, especially, in pulmonary insufficiency, ability to perform mild systemic hypothermia, blood preservation by means of reservoir and cardiotomy “sucker” and immediate replacement when necessary. The most important advantage is rapid deep hypothermia on demand and to be able to come to circulatory arrest. In type B dissection caused by tearing of the arch, diffuse aortic calcifications, proximal clamp lacerations, circulatory arrest may have to be applied. To our opinion, CPB with distal perfusion in surgery of acute type B dissection is the most reliable technique.