Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: state-of-the-art 2020

Abstract

Pulmonary endarterectomy is the treatment of choice for patients with operable chronic thromboembolic pulmonary hypertension (CTEPH) as it is potentially curative. In expert centers that conduct > 50 pulmonary endarterectomy procedures per year, peri- and post-surgical mortality rates are very low and long-term outcomes are excellent, with three-year post-operative survival of > 80%. Therapeutic decisions in CTEPH are based largely on the location of the arterial obstruction, with pulmonary endarterectomy for obstructions in main, lobar, and segmental vessels, and balloon pulmonary angioplasty and medical therapy for small-vessel disease. Medical therapy is also an option for patients with persistent/recurrent pulmonary hypertension after pulmonary endarterectomy or balloon pulmonary angioplasty. With increasing surgical experience and improvements in instruments and procedures, an increasing number of patients are now considered operable who would previously have been inoperable, including some patients with subsegmental disease. At our University (University of California San Diego), around 200 pulmonary endarterectomy procedures are performed every year and several advances have been developed, including resection of more distal disease, availability of pulmonary endarterectomy to patients previously considered to be at too high risk for surgery, improved management of post-pulmonary endarterectomy complications, and minimally invasive pulmonary endarterectomy. Pulmonary endarterectomy can be combined with other treatment modalities, including balloon pulmonary angioplasty, medical therapy for persistent/recurrent pulmonary hypertension after pulmonary endarterectomy, and medical therapy or balloon pulmonary angioplasty as bridging therapy before surgery. Data on these combinations are, however, limited. Combination treatment should therefore be considered on an individual patient basis. In the future, however, multimodal therapy with pulmonary endarterectomy, balloon pulmonary angioplasty, and/or medical therapy is likely to be an important treatment option for many patients.

Keywords: chronic thromboembolic pulmonary hypertension; pulmonary endarterectomy; surgical outcomes.

Fig. 1.

Survival rates after PEA increase with the experience of the surgical center. Data from 26 European centers and one Canadian center. PEA: pulmonary endarterectomy.

Fig. 2.

The management options for CTEPH target pathogenic manifestations in different parts of the pulmonary vascular bed. (a) Computed tomography scan of a pulmonary artery. (b) Organized fibrotic material removed during PEA. (c) Selective pulmonary angiogram of segmental and subsegmental pulmonary arteries, showing irregular vessel contour and occlusion, typical of CTEPH. (d) Microscopic examination showing a luminal filling defect with recanalized chronic thrombus (web lesion) and no evidence of vasculopathy in the subsegmental artery. (e) Intimal fibromuscular proliferation. (f) Plexiform lesion and vessel occlusion due to vasculopathy and proliferation. Adapted from Madani et al. [part (e) from Moser and Bloor] and Madani. A schematic representation of a pulmonary artery is shown (note that vessel diameter is not to scale). PEA is used to remove thromboembolic lesions primarily in the proximal main artery (diameter of ∼1–3 cm), and lobar and segmental arteries;^, in expert surgical centers, lesions in distally located mid-segmental and subsegmental branches can be targeted by PEA, down to vessels of 2 mm in diameter. BPA mainly targets distal lesions in the segmental and subsegmental vasculature, down to small pulmonary arteries of 2–5 mm in diameter. Medical therapy targets microvasculopathy, including intimal thickening and fibromuscular proliferation, in vessels of 0.1–0.5 mm in diameter. Typical surgical specimens based on the most proximal level of obstruction are shown. The scale is in cm. BPA: balloon pulmonary angioplasty; CTEPH: chronic thromboembolic pulmonary hypertension; PEA: pulmonary endarterectomy.