BACKGROUND Between 16% and 51% of patients with chronic thromboembolic pulmonary hypertension will have residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Whether residual PH is related to remaining (sub-)segmental macrovascular lesions or to microvascular disease is unknown. New imaging techniques can provide detailed information about (sub-)segmental pulmonary arteries and parenchymal perfusion. The aim of this study was to describe the prevalence after PEA of remaining (sub-)segmental vascular lesions on electrocardiogram-gated computed tomography pulmonary angiography (CTPA) and parenchymal hypoperfusion on magnetic resonance imaging (MRI) and to relate these imaging abnormalities to the presence or absence of residual PH after PEA. METHODS In a prospective cohort of patients with operable chronic thromboembolic pulmonary hypertension, hemodynamics, CTPA, and lung perfusion MRI were performed before and 6 months after PEA. The percentage of (sub-)segmental vascular lesions was calculated on CTPA and parenchymal hypoperfusion on lung perfusion MRI. RESULTS PEA led to significant improvements in hemodynamics and a reduction of imaging abnormalities. Residual PH was present in 45% of patients after PEA, whereas remaining (sub-)segmental vascular lesions and parenchymal hypoperfusion were present in 20% and 21% of the pulmonary vasculature, respectively. Patients with and without residual PH after PEA had similar percentages of remaining (sub-)segmental vascular lesions (25% ± 14% vs 17% ± 15%; p = 0.16) and similar degrees of parenchymal hypoperfusion (20% ± 7% vs 19% ± 6%; p = 0.63). CONCLUSIONS After successful PEA, advanced imaging shows that around 20% of the pulmonary vasculature remains abnormal, independent of the presence of residual PH. This may suggest that microvascular disease, rather than residual macrovascular lesions, plays a prominent role in residual PH after PEA.

中文翻译：

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慢性血栓栓塞性肺动脉高压的肺动脉内膜切除术后的肺血管成像特征。

背景技术慢性血栓栓塞性肺动脉高压患者中有16％至51％会在肺动脉内膜切除术（PEA）后残留肺动脉高压（PH）。残留的PH是否与剩余的（部分）大血管病变或微血管疾病有关仍是未知的。新的成像技术可以提供有关（亚）节段性肺动脉和实质灌注的详细信息。这项研究的目的是描述心电图门控计算机断层扫描肺血管造影（CTPA）和磁共振成像（MRI）上的实质性低灌注对剩余（亚）段血管病变的PEA患病率，并将这些成像异常与PEA后是否存在残留PH。方法在可手术的慢性血栓栓塞性肺动脉高压患者的前瞻性队列中，在PEA之前和6个月后进行血流动力学，CTPA和肺灌注MRI。在CTPA和肺灌注MRI上计算（亚）节段性血管病变的百分比和实质性低灌注。结果PEA显着改善了血流动力学，并减少了影像学异常。PEA后有45％的患者存在残余PH，而剩余的（亚）节段性血管病变和实质性低灌注分别存在于20％和21％的肺血管系统中。PEA后有或没有残余PH的患者，残余（亚）节段性血管病变的百分比相似（25％±14％vs 17％±15％； p = 0.16），并且实质性低灌注程度相似（20％±7％vs 19％±6％；p = 0.63）。结论成功进行PEA后，高级影像检查显示约20％的肺血管系统保持异常，而与残留PH的存在无关。这可能表明，微血管疾病而不是残留的大血管病变在PEA后残留的PH中起着重要作用。