Extrinsic compression of coronary and pulmonary vasculature

Pulmonary artery stenting for palliative treatment of refractory hypoxaemia in a patient with small cell lung cancer

Pulmonary artery stenosis (PAS) is most encountered in the paediatric population as a congenital anomaly. In adults, PAS from extrinsic compression of the pulmonary artery (PA) results from conditions such as fibrosing mediastinitis, malignancy, infections and anastomotic stenosis after lung transplantation. We describe a woman in her 50s with extensive stage small cell lung cancer who presented with symptoms of shortness of breath and hypoxaemic respiratory failure. CT angiography chest showed a progressively enlarging mediastinal mass causing severe compressive stenosis of the right PA and moderate stenosis of the left PA. Her symptoms did not improve despite using bronchodilators and intravenous steroids. Pulmonary angiography confirmed clinically significant stenosis of her right PA. The placement of a single stent within the right PA provided significant improvement in symptoms and supplemental oxygen requirement within 24 hours.

Pulmonary artery stenting in cancer patients: A single-center experience

Endovascular stenting of the pulmonary artery treats arterial stenosis from pulmonary hypertension, congenital heart defects, or post-transplant stricture. Patients with malignant extrinsic pulmonary arterial compression, secondary to large mediastinal or pulmonary masses, often present with dyspnea, hypoxemia, and right ventricular failure. Conventional therapies like surgery, chemotherapy, and radiation are often slow and fail to promptly resolve acute symptoms. Balloon angioplasty and stenting have been explored as a rapid treatment to alleviate symptoms of external pulmonary artery compression. Despite its potential, the adoption of this procedure is limited due to risks like stent misplacement, migration, cardiac arrhythmias, and arterial rupture. This paper presents 3 cases of pulmonary angiography and stenting performed for malignant extrinsic pulmonary artery compression. These cases aim to demonstrate the feasibility of pulmonary artery stenting, encouraging its consideration as a palliative option for symptomatic patients with this condition.

Endovascular interventions in cancer patients with compromise of the mediastinal vasculature: a review

The mediastinal vasculature can be affected by various etiologies in cancer patients. Both direct and indirect sequela of cancer may result in life-threatening clinical presentations. Tumor growth may cause vessel narrowing and decreased blood flow from either extrinsic mass effect, invasion into the vascular wall, or tumor thrombus within the lumen. In addition, cancer patients are predisposed to indirect sequela to the mediastinal vasculature from an increased risk of benign thromboembolic events, tumor thrombus, or iatrogenic complications during cancer treatments. Benign thrombus may result in partial or complete occlusion of the superior vena cava (SVC) or pulmonary artery. Vascular damage such as pseudoaneurysm or stricture may result from iatrogenic complications from radiation therapy, surgery, or other interventions. The clinical presentation of the vascular compromise is dictated by the vascular anatomical structure that is affected and the type of injury. In the appropriate clinical scenario, endovascular treatments may be pursued. These minimally invasive procedures include balloon venoplasty and angioplasty, stent placement, catheter-directed thrombolysis, embolectomy, and embolization. This review discusses the most common endovascular interventions for vascular compromise based on the great vessel affected: the SVC, pulmonary artery, pulmonary vein, bronchial arteries, or the aorta and supra-aortic arteries. Indications for treatment are discussed, with particular attention to disease etiology and clinical presentation.

Right pulmonary artery compression following acute type A aortic dissection resulting in acute right ventricular heart failure: A case report

Right ventricular failure is a mechanism of hemodynamic collapse in acute aortic dissection. Mostly RV failure happens as a result of coronary malperfusion secondary to compression of right coronary artery ostium by the false lumen of type A aortic dissection or the dissection flap involving this coronary artery. Another mechanism is compression of pulmonary artery and an acute rise of pulmonary pressure below the level of obstruction, which is rarely reported. Herein, we presented an 82-year-old man who was admitted with type A aortic dissection in whom echocardiographic examination revealed right pulmonary artery compression resulting in acute right ventricular failure.

A Case Report of Pulmonary Vein Stenosis Within the Labyrinth of Fibrosing Mediastinitis

This case centers on a 76-year-old male experiencing exertional dyspnea and hemoptysis, with a medical history marked by recurrent pulmonary embolism and chronic obstructive pulmonary disease (COPD). Notably, he resides in a histoplasmosis-endemic area. A computed tomography (CT) pulmonary embolism scan revealed notable findings, including an enlarged right lower pulmonary artery, vascular congestion, atelectasis, and a mass exerting pressure on the right lower pulmonary vein. Biopsy results identified the mass as fibrosing mediastinitis, likely attributed to histoplasmosis. A transthoracic echocardiogram indicated right ventricular dilatation, impaired function, and a right ventricular systolic pressure of 63 mm Hg. During right heart catheterization, the patient displayed disparate pulmonary artery wedge pressures (PAWPs) between the right and left sides. This discrepancy was linked to a blunted back wave from the left atrium to the catheter, induced by pulmonary vein compression. Although an infrequent phenomenon, the recorded asymmetry in PAWPs played a crucial role in guiding accurate patient management. The absence of subsequent evaluation of PAWP on the left side could have altered the treatment plan, potentially delaying appropriate patient care. This case emphasizes the necessity of thorough exploration with right heart catheterization when clinical symptoms warrant, highlighting the importance of standardized practices in such procedures.

Coronary artery disease in adults with congenital heart disease

The increasing population of adult patients with congenital heart disease (ACHD) is at risk of developing coronary artery disease (CAD) and other atherosclerotic cardiovascular diseases due to exposure to cardiovascular risk factors. The impact of this exposure is growing larger as life expectancy of these subjects increases with the progressive improvement in management of congenital heart disease. Studies have shown that ACHD patients have a higher risk for CAD than their non-ACHD matches, highlighting the need for awareness and prevention efforts among congenital heart disease specialists and non-ACHD cardiologists. At the same time, ACHD patients with CAD often present specific characteristics all practicing cardiologists should be aware of. While further research is needed to fully understand the mechanisms underlying the higher CAD risk in this population, this article summarizes key evidence on CAD in ACHD and emphasizes on one hand the importance of early screening and management of known cardiovascular risk factors in ACHD patients, particularly those who are younger, female, or have more complex/severe CHD. On the other hand, it calls for a broader knowledge of ACHD risk for CAD and its peculiarities among all cardiologists.

Potential Value of FAPI PET/CT in the Detection and Treatment of Fibrosing Mediastinitis: Preclinical and Pilot Clinical Investigation

Fibrosing mediastinitis (FM) is a rare proliferative disease within the mediastinum that leads to pulmonary hypertension, which has been regarded as a major cause of death. This study aims to evaluate the potential value of fibroblast activation protein inhibitor (FAPI)-PET/CT in the integration of diagnosis and treatment of FM through targeting FAPI in fibrosis rats and provide a theoretical basis for clinical management of FM patients. By performing a 18F-FAPI PET/CT scan, the presence of FAPI-avid in the fibrotic lesion was determined. Through a fibrosis rat model, 18F-FAPI-74 was used for lesion imaging and 177Lu-FAPI-46 was utilized to investigate the potential therapeutic effect on FM in vivo. In addition, biodistribution analysis and radiation dosimetry were carried out. With the 177Lu-FAPI-46 pharmacokinetic data of rats as the input, the estimated dose for female adults was computed, which can provide some useful information for the safe application of radiolabeled FAPI in the detection and treatment of FM in patients. Then, major findings on the use of FAPI PET/CT and SPECT/CT in FM were presented. 18F-FAPI-74 showed a high-level uptake in FM lesions of patients (SUVmax 7.94 ± 0.26), which was also observed in fibrosis rats (SUVmax 2.11 ± 0.23). Consistently, SPECT/CT imaging of fibrosis rats also revealed that 177Lu-FAPI-46-avid was active for up to 60 h in fibrotic lesions. In addition to this robust diagnostic performance, a possible therapeutic impact was evaluated as well. It turned out that no spontaneous healing of lesions was observed in the control group, whereas there was complete healing on day 9, day 11, and day 14 in the 30, 100, and 300 MBq groups, respectively. With a significant difference in the free of event rate in the Kaplan-Meier curve among four groups (P < 0.001), a dose of 300 MBq displayed the best therapeutic effect, and no obvious damage was observed in the kidney. Furthermore, organ-absorbed doses and an effective dose (0.4320 mSv/MBq) of 177Lu-FAPI-46 presumed for patients were assumed to give a preliminary indication of its safe use in clinical practice. In conclusion, 18F-FAPI-46 PET/CT can be a potentially valuable tool for the diagnosis of FM. Of note, 177Lu-FAPI-46 may be a novel and safe radiolabeled reagent for the integration of diagnosis and treatment of FM.