Distal vessel pulmonary thromboendarterectomy: Results from a single institution

An overview of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and progressive condition caused by unresolved pulmonary arterial obstructions, leading to secondary microvasculopathy and poor hemodynamics. Pulmonary endarterectomy (PEA) is the first-line treatment for operable patients. Balloon pulmonary angioplasty (BPA) has emerged as a promising treatment option for patients considered inoperable due to distal lesions, comorbidities, or residual pulmonary hypertension (PH) after PEA. Following the development of the BPA in safety and efficacy, it has been widely adopted and utilized across the globe.

AREAS COVERED

This review covers the historical development of BPA, its clinical role, and technical methodologies. Medical therapies as an adjunctive role in CTEPH management are also discussed. Finally, we present recent BPA experiences from our institution, highlighting hemodynamic outcomes and survival rates.

EXPERT OPINION

BPA is a transformative treatment for patients with CTEPH, particularly those ineligible for PEA. Procedural refinements have significantly improved safety and efficacy. However, challenges remain, including the standardization of decision-making processes for management and the establishment of optimal treatment goals. Ongoing research continues to refine the role of BPA to improve outcomes and enhance the quality of life for patients with CTEPH. [Figure: see text].

Pulmonary Thromboendarterectomy: The Potentially Curative Treatment of Choice for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a consequence of unresolved organized thromboembolic obstruction of the pulmonary arteries, which can cause pulmonary hypertension and right ventricular failure. Owing to its subtle signs, determining its exact incidence and prevalence is challenging. Furthermore, CTEPH may also present without any prior venous thromboembolic history, contributing to underdiagnosis and undertreatment. Diagnosis requires a high degree of suspicion and is ruled out by a normal ventilation/perfusion ratio scintigraphy. Additional imaging by computed tomography and/or conventional angiography, as well as right heart catheterization, are required to confirm CTEPH and formulate treatment plans. Pulmonary thromboendarterectomy is the treatment of choice for eligible patients and can be potentially curative. Pulmonary thromboendarterectomy has a low mortality rate of 1% to 2% at expert centers and offers excellent long-term survival. Furthermore, recent advances in the techniques allow distal endarterectomy with comparable outcomes. Alternative treatment options are available for those who may not be operable or have prohibitive risks, providing some benefit. However, CTEPH is a progressive disease with low long-term survival rates if left untreated. Given excellent short- and long-term outcomes of surgery, as well as the benefits seen with other treatment modalities in noncandidate patients, it is crucial that precapillary pulmonary hypertension and CTEPH are ruled out in any patient with dyspnea of unexplained etiology. These patients should be referred to expert centers where accurate operability assessment and appropriate treatment strategies can be offered by a multidisciplinary team.

Computed tomography identifies sex-specific differences in surgical chronic thromboembolic pulmonary hypertension

Background

Registry data suggest women are less likely than men to undergo pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension despite a similar proportion of proximal vs distal disease. We hypothesized that sex-specific differences could be elicited with a computed tomography pulmonary angiography analysis beyond proximal vs distal.

Methods

Preoperative computed tomography pulmonary angiography of patients who underwent pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension from January 2017 to September 2021 was analyzed. The pulmonary vascular tree was divided into 32 named vessels with chronic thromboembolism presence and lesion type recorded for each vessel. If no lesion was identified in a segmental vessel, subsegmental disease was recorded when present.

Results

One hundred forty-four patients (mean age 57 ± 15 years, 78 women) were included. There were no sex differences in baseline hemodynamics. Men had more vessels involved than women (mean 20.3 vs 17.1, p = 0.004) and had fewer disease-free pulmonary segments (mean 4.9 ± 4.3 vs 7.6 ± 5.5, p = 0.001). Men had a greater number of webs, eccentric thickening, and occlusions. The distribution of lesion type did not significantly differ between sexes at the main or lobar level but men had significantly more lesions in the segmental vasculature while women had a higher proportion of subsegmental lesions (p < 0.001).

Conclusions

Sex-specific differences in chronic thromboembolic pulmonary hypertension are demonstrated on computed tomography pulmonary angiography in overall distribution and lesion type at the segmental and subsegmental level with women having fewer and more distal lesions despite similar hemodynamics.

Chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary hypertension is a complication of pulmonary embolism and a treatable cause of pulmonary hypertension. The pathology is a unique combination of mechanical obstruction due to failure of clot resolution, and a variable degree of microvascular disease, that both contribute to pulmonary vascular resistance. Accordingly, multiple treatments have been developed to target the disease components. However, accurate diagnosis is often delayed. Evaluation includes high-quality imaging modalities, necessary for disease confirmation and for appropriate treatment planning. All patients with chronic thromboembolic pulmonary disease, and especially those with pulmonary hypertension, should be referred to expert centres for multidisciplinary team decision on treatment. The first decision remains assessment of operability, and the best improvement in symptoms and survival is achieved by the mechanical therapies, pulmonary endarterectomy and balloon pulmonary angioplasty. With the advances in multimodal therapies, excellent outcomes can be achieved with 3-year survival of >90%.

NT-pro-BNP is predictive of morbidity and mortality after pulmonary thromboendarterectomy and is independent of preoperative hemodynamics

Current predictors of clinical outcomes after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are largely limited to preoperative clinical characteristics. N-terminal-pro-brain natriuretic peptide (NT-pro-BNP), a biomarker of right ventricular dysfunction, has not yet been well described as one such predictor. From 2017 to 2021, 816 patients with CTEPH referred to the University of California, San Diego for PTE were reviewed for differences in NT-pro-BNP to predict preoperative characteristics and postoperative outcomes up to 30 days post-PTE. For analysis, NT-pro-BNP was dichotomized to less than/equal to or greater than 1000 pg/mL based on the mean of the study population. Mean NT-pro-BNP was 1095.9 ±1783.4 pg/mL and median was 402.5 pg/mL (interquartile range: 119.5-1410.8). Of the 816 patients included, 250 had NT-pro-BNP > 1000 pg/mL. Those with NT-pro-BNP > 1000 pg/mL were significantly more likely to have worse preoperative functional class (III-IV) and worse preoperative hemodynamics. Patients with NT-pro-BNP > 1000 pg/mL also tended to have more postoperative complications including reperfusion pulmonary edema (22% vs. 5.1%, p < 0.001), airway hemorrhage (8.4% vs. 4.9%, p = 0.075), residual pulmonary hypertension (11.9% vs. 3.1%, p < 0.001), and 30-day mortality (4.8% vs. 1.1%, p = 0.001). Even after adjusting for confounders, patients with NT-pro-BNP > 1000 pg/mL had a 2.48 times higher odds (95% confidence interval: 1.45-4.00) of reaching a combined endpoint that included the above complications. Preoperative NT-pro-BNP > 1000 pg/mL is a strong predictor of more severe preoperative hemodynamics and identifies patients at higher risk for postoperative complications.

ERS International Congress 2023: highlights from the Pulmonary Vascular Diseases Assembly

Pulmonary vascular diseases such as pulmonary embolism and pulmonary hypertension are important and frequently under-recognised conditions. This article provides an overview of key highlights in pulmonary vascular diseases from the European Respiratory Society International Congress 2023. This includes insights into disease modification in pulmonary arterial hypertension and novel therapies such as sotatercept and seralutinib. Exciting developments in our understanding of the mechanisms underpinning pulmonary hypertension associated with interstitial lung disease are also explored. A comprehensive overview of the complex relationship between acute pulmonary embolism and chronic thromboembolic pulmonary hypertension (CTEPH) is provided along with our current understanding of the molecular determinants of CTEPH. The importance of multidisciplinary and holistic care cannot be understated, and this article also addresses advances beyond medication, with a special focus on exercise training and rehabilitation.

Clinical-radiological-pathological correlation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and potentially life-threatening complication of acute pulmonary embolism. It is characterised by persistent fibro-thrombotic pulmonary vascular obstructions and elevated pulmonary artery pressure leading to right heart failure. The diagnosis is based on two steps, as follows: 1) suspicion based on symptoms, echocardiography and ventilation/perfusion scan and 2) confirmation with right heart catheterisation, computed tomography pulmonary angiography and, in most cases, digital subtraction angiography. The management of CTEPH requires a multimodal approach, involving medical therapy, interventional procedures and surgical intervention. This clinical-radiological-pathological correlation paper illustrates the diagnostic and therapeutic management of two patients. The first had chronic thromboembolic pulmonary disease without pulmonary hypertension at rest but with significant physical limitation and was successfully treated with pulmonary endarterectomy. The second patient had CTEPH associated with splenectomy and was considered unsuitable for surgery because of exclusive subsegmental lesions combined with severe pulmonary hypertension. The patient benefited from multimodal treatment involving medical therapy followed by multiple sessions of balloon pulmonary angioplasty. Both patients had normalised functional capacity and pulmonary haemodynamics 3-6 months after the interventional treatment. These two examples show that chronic thromboembolic pulmonary diseases are curable if diagnosed promptly and referred to CTEPH centres for specialist treatment.

Balloon pulmonary angioplasty in the current era of CTEPH treatment: How did we get here?

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by persistent organized thromboembolic obstruction of the pulmonary arteries from incompletely resolved pulmonary embolism. The treatment of choice is pulmonary thromboendarterectomy (PTE) surgery and all patients should be evaluated for operability candidacy. Despite advancements in PTE technique allowing more segmental-subsegmental surgeries, up to a third of patients with CTEPH may still be considered inoperable. Over the past decade, there have been increasing treatment options for these inoperable CTEPH patients. Balloon pulmonary angioplasty (BPA) is a percutaneous-based interventional treatment option for select CTEPH cases. Early BPA experiences were plagued by high complication rates, but further refinements in technique and equipment pioneered by Japan led to the worldwide spread and adoption of BPA. Multiple centers have shown that patients experience significant improvements in hemodynamics, quality of life, exercise capacity, and survival with BPA treatment. There remain many questions on best practices, but BPA has evolved into a pivotal cornerstone of CTEPH treatment.