Surgical specimens, haemodynamics and long-term outcomes after pulmonary endarterectomy

Abstract

BackgroundChronic thromboembolic pulmonary hypertension is surgically curable by pulmonary endarterectomy (PEA). It is unclear whether PEA impacts primarily steady state right ventricular afterload (ie, pulmonary vascular resistance (PVR)) or pulsatile right ventricular afterload (ie, pulmonary arterial compliance (CPA)). Our objectives were to (1) quantify PEA specimens and measure the impact of PEA on PVR and CPA in a structure/function study and (2) analyse the effects of haemodynamic changes on long-term survival/freedom of lung transplantation in an outcome study.MethodsThrombi were laid out, weighed, photographed and measured. PVR, CPA and resistance times compliance (RC-time) were assessed at baseline, within 4 days after PEA (‘immediately postoperative’) and 1 year after PEA, in 110 consecutive patients who were followed for 34.5 (11.9; 78.3) months.ResultsLengths and numbers of PEA specimen tails were inversely correlated with immediate postoperative PVR (p<0.0001, r=−0.566; p<0.0001, r=−0.580). PVR and CPA normalised immediately postoperatively while RC-time remained unchanged. Immediate postoperative PVR was the only predictor of long-term survival/freedom of lung transplantation (p<0.0001). Patients with immediate postoperative PVR<590 dynes.s.cm−5 had better long-term outcomes than patients with PVR≥590 dynes.s.cm−5 (p<0.0001, respectively).ConclusionsPEA immediately decreased PVR and increased CPA under a constant RC-time. However, immediate postoperative PVR was the only predictor of long-term survival/freedom of lung transplantation. Our study confirms the importance of a complete, bilateral surgical endarterectomy. Low PVR measured immediately postoperative predicts excellent long-term outcome.

2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension

“…Preoperative and immediate postoperative PVR is a long-term predictor of prognosis [429]. The final step in the diagnostic pathway is selective pulmonary angiography in the anterior-posterior and lateral projections illustrating ring-like stenosis, webs ('slits'), pouches, wall irregularities, complete vascular obstructions as well as bronchial collaterals, and supports the technical assessment of operability.…”

Update on Chronic Thromboembolic Pulmonary Hypertension

“…Patients with immediate postoperative PVR <590 dyne·s/cm 5 had better long-term outcomes than patients with PVR ≥590 dyne·s/cm 5 . 79 In other series, patients with a postoperative PVR ≥500 dyne·s/cm 5 had a 30-day mortality of ≈10.3% compared with a 0.9% mortality rate for patients with postoperative PVR of <500 dyne·s/cm 5 . Patients with persistent exertional dyspnea after successful PEA still display an abnormal pulmonary hemodynamic response to exercise.…”

Pulmonary vascular resistance and compliance relationship in pulmonary hypertension

“…It has been proposed that a unique feature of the pulmonary circulation is that PVR and total arterial compliance are tightly coupled through an inverse hyperbolic relationship, resulting in a constant RC-time product that prevails in both health and disease [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. A constant RC-time product has important implications for the assessment of RV afterload, namely that PVR and total arterial compliance are redundant measurements and knowledge of one enables the derivation of the other.…”