Midterm Results and Surgical Technique Considerations in Pulmonary Thromboendarterectomy. Is Hypothermic Circulatory Arrest Always Necessary?

Pulmonary thromboendarterctomy is a curative surgery. However, it is associated with high mortality and morbidity. It’s accomplished under a period of circulatory arrest, thereby increasing the risk of surgical complications, especially neurologic sequelae. In present study, the surgical result of this procedure without the use of circulatory arrest has been presented. Eleven patients with the mean age of 34±11 year underwent pulmonary thromboendarterctomy, using CPB, moderate hypothermia, and low pressure perfusion by single surgeon from April 2005 to June 2008 in the Rajaee Heart Center, Tehran. Half the patients had the evidence of involvement of segmental branches of pulmonary artery in CT angiography. Most patients presented in the NYHA class III. The mean pre-op PA pressure was 91.3±26mmHg. All patients were followed between 3-36 months. There were three mortality cases in this study and the first two, were among the early experiences of the surgeon. The most common cause of mortality was respiratory failure and right-sided heart failure secondary to residual pulmonary hypertension. NYHA class improved in all survived. The mean post-op PA pressure was 39±13mmHg. Patients were intubated on the average of 75±4 hours. No neurologic complications were seen. One patient required extracorporeal life support system (ECLS) to wean from CPB off. Two patients had significant post-op bleeding due to coagulopathy and in the third one surgical source resulted in re-exploration. In this series, mortality was more than one expected. However with increased experience and the use of meticulous surgical techniques and improvement in peri-operative cares, mortality reduced significantly. Sufficient thromboendarterectomy is feasible without the use of circulatory arrest, while decreasing probable complication of TCA, especially neurologic ones. Failure to ameliorate pulmonary hypertension, during surgery, results, in high mortality and morbidity.