[ANAESTHETIC MANAGEMENT OF RECONSTRUCTIVE SURGERY ON THE AORTIC ARCH: THE NUANCES OF ORGAN PROTECTION]

Aortic arch reconstruction is one of the most difficult surgical procedures. Therefore the aims of our study were: to choose appropriate flow rate for antegrade cerebral perfusion and assess its adequacy in relation to cerebral metabolic demands; to evaluate safety of temperature settings during the surgery; to assess the effectiveness of chosen protocol for brain and visceral organ protection during aortic arch reconstruction surgery. Our study included 67 patients. Patients of the first group (n = 33) underwent aortic arch reconstruction with antegrade cerebral perfusion and hypothermic circulatory arrest (target core temperature 26 °C). The second group (n = 34) underwent ascending aorta repair using cardiopulmonary bypass with modest hypothermia (target core temperature 32 °C). Cerebral and tissue oxygenation monitoring was performed in all patients. In the first group transcranial Doppler monitoring and jugular venous bulb catheterization were performed. Target core temperature during rewarming was 36 °C. In the first group air-warming device in addition to fluid warming was used. In all patients cognitive function was assessed before and after surgery. The multimodal monitoring allowed to dynamically adjust flow rate of antegrade cerebral perfusion. As a result cerebral SO2 and linear velocity were maintained in acceptable range, while flow rate varied significantly from 5.8 to 16.5 ml/ kg/min (average rate 13.4 ± 3.69 ml/kg/min).

Combined use of cerebral oximetry and transcranial Doppler monitoring allows assessing how oxygen delivery meets metabolic demands of the brain during antegrade cerebral perfusion. This method allows to maintain the proper flow rate of antegrade cerebral perfusion and to choose an appropriate modification of perfusion (unilateral vs bilateral). Multichannel monitoring of core temperature and combined use of air- and fluid warming techniques are required for effective temperature management.