Results of pulmonary thromboendarterectomy depending on different levels of pulmonary vascular resistance and angiographic index of the pulmonary artery lesion

Objective. Pulmonary endarterectomy is a first-choice treatment for patients with chronic thromboembolic pulmonary hypertension. Data describing the results of the operation with different levels of pulmonary vascular resistance (PVR) depending on the spread and percentage of pulmonary artery disease are not declared in the world literature. The aim of our study is to evaluate and compare the hospital results of the operation in patients with different levels of pulmonary vascular resistance, depending on the CT-angiographic index of the pulmonary artery lesion.

Materials and methods. A retro-prospective study was conducted, which included 52 patients. All patients were divided into 2 groups, depending on the levels of pulmonary vascular resistance (PVR): group 1 included 31 patients with PVR<1000 dyne×s/cm⁵, group 2 – 21 patients with PVR>1000 dyne×s/cm⁵. Data of the preoperative right heart catheterization in groups 1 and 2, respectively: mean pulmonary artery pressure (mPAP) – 44.4±8.3 and 56.9±9.6 mm Hg, pulmonary artery wedge pressure – 7.3±2.4 and 6±1.5 mm. Hg, cardiac output (CO) – 3.9±0.9 and 3.2±0.6 l/min, cardiac index (CI) – 2±0.5 and 1.6±0.4 l/min/m², PVR – 767±174 and 1272.6±186.4 dyn×sec/cm⁵. The operation was carried out bilaterally according to a standard protocol with cardiopulmonary bypass, deep hypothermia and circulatory arrest.

Results. Data of the right heart catheterization on the first day after the operation in first and second groups, respectively: mPAP – 28.5±6.3 and 35.78±4.2 mm Hg, PVR – 253.39±85.5 and 333.9±101.9 dyne×s/cm⁵, CO – 5.37±0.9 and 5, 2±1.1 l/min, CI – 2.69±0.39 and 2.6±0.4 l/min/m². There was a significant decrease of pulmonary hypertension (p<0.05) in the early postoperative period, in both groups. However, a detailed analysis of the obtained data revealed that in patients with pulmonary vascular resistance of more than 1000 dyne×s/cm⁵ with a pulmonary artery lesion index of less than 50%, a significant course of the early postoperative period along the combined endpoint was observed. The intensive care unit stay was 4 days in average in both groups. The need for a tracheostomy for the prolongation of artificial ventilation of the lungs was in 2 and 1 cases in first and second groups, respectively. In the first group, there were 5 cases of transient neurological disorders, which regressed at the time of discharge. Two patients in the second group died.

Conclusion. Despite the varying levels of baseline PVR, a significant improvement in hemodynamic parameters is observed in the early postoperative period, although patients in group 2 were less proven to normalization of pulmonary hemodynamics. However, a detailed comparative analysis revealed that the most severe category of patients are patients with PVR>1000 dyne×s/cm⁵, with pulmonary artery lesion index of less than 50%. Thus, the calculation of the CT-angiographic index of pulmonary artery diseases an additional diagnostic method to rate the risks of surgery, especially in patients with a high level of preoperative pulmonary hypertension

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