Catheter-based intervention for pulmonary vein stenosis due to fibrosing mediastinitis: The Mayo Clinic experience

Pulmonary artery vasodilators for treatment of pulmonary hypertension complicating fibrosing mediastinitis

Fibrosing mediastinitis (FM) is a heterogeneous disease characterized by sclerosing fibrosis of mediastinal structures. Pulmonary hypertension (PH) may complicate the course of the disease and can contribute significantly to the morbidity of FM. Due to the rarity and complexity of the disease, evidence-based guidelines are not currently available, and the optimal treatment approach is unknown. Management approaches should be individualized, and current techniques are often unsatisfactory. Here, we present two cases of PH complicating FM that were managed using pulmonary artery vasodilator therapy with excellent hemodynamic response.

Fibrosing mediastinitis resulting in unilateral pulmonary artery hypertension

Fibrosing mediastinitis (FM), a rare disorder that is further classified as excessive fibrous tissue that occurs within the mediastinum. Classically, presenting with manifestations dependent on where the fibrous tissue is located. In rare instances, compression of pulmonary vasculature can lead to Pulmonary Hypertension. Pulmonary Hypertension- Fibrosing Mediastinitis (PH-FM) represents a rare complication with minimal available data on incidence. In regards to all-cause mortality, no specific data regarding the prognosis of PH-FM exist. With the scarcity of data, this case aids in the advancement of literature due to unique unilateral obstruction and the need for further analysis on our current treatment.

Successful simultaneous stenting of a pulmonary artery and vein in pulmonary vascular stenosis due to silicosis. Case report and literature review

A 58-year-old patient was admitted to the emergency department due to severe respiratory insufficiency. Anamnesis revealed that the patient had experienced increasing stress dyspnea for a few months. Upon imaging, an acute pulmonary embolism was excluded, but peribronchial and hilar soft tissue proliferation with compression of central parts of the pulmonary circulation was found. The patient had a history of silicosis. The histology report showed tumor-free lymph node particles with prominent anthracotic pigment and dust depositions without evidence of IgG4-associated disease. The patient was administered steroid therapy and underwent simultaneous stenting of the left interlobular pulmonary artery and the upper right pulmonary vein. As a result, a significant improvement in symptoms and physical performance was achieved. The diagnosis of inflammatory or, in particular, fibrosing mediastinal processes can be challenging and important clinical symptoms must be taken into account, especially if the pulmonary vasculature is involved. In such cases, the possibility of interventional procedures should be examined in addition to drug therapy options.

Refractory pleural effusion as a rare complication of pulmonary vascular stenosis induced by fibrosing mediastinitis: a case report and literature review

Fibrosing mediastinitis (FM) is a progressive, life-threatening disease characterized by extrinsic compression of mediastinal bronchovascular structures, and the clinical manifestations largely depend upon the affected structures. Pleural effusion is rarely reported in patients with FM. We herein describe a 70-year-old man who presented with recurrent breathlessness and refractory left pleural effusion. He was misdiagnosed with and treated for tuberculous pleurisy for several months. Thoracentesis revealed a transudative pleural effusion, and a contrast-enhanced computed tomography scan of the thorax showed an extensive mediastinal soft tissue mass consistent with FM. Pulmonary angiography demonstrated pulmonary artery stenosis on the right side and pulmonary vein stenosis mainly on the left side. After measurement of the pulmonary arterial pressure by right heart catheterization, the patient was diagnosed with pulmonary hypertension associated with FM. He underwent balloon angioplasty and stent implantation of the stenosed pulmonary vessels, which led to long-term improvement in his breathlessness and pleural effusion. Our systematic review of the literature highlights that pleural effusion can be an uncommon complication of FM and requires careful etiological differentiation.

CD4+CTLs in Fibrosing Mediastinitis Linked to Histoplasma capsulatum

Although fibrotic disorders are frequently assumed to be linked to T_H2 cells, quantitative tissue interrogation studies have rarely been performed to establish this link and certainly many fibrotic diseases do not fall within the type 2/allergic disease spectrum. We have previously linked two human autoimmune fibrotic diseases, IgG4-related disease and systemic sclerosis, to the clonal expansion and lesional accumulation of CD4⁺CTLs. In both these diseases T_H2 cell accumulation was found to be sparse. Fibrosing mediastinitis linked to Histoplasma capsulatum infection histologically resembles IgG4-related disease in terms of the inflammatory infiltrate and fibrosis, and it provides an example of a fibrotic disease of infectious origin in which the potentially profibrotic T cells may be induced and reactivated by fungal Ags. We show in this study that, in this human disease, CD4⁺CTLs accumulate in the blood, are clonally expanded, infiltrate into disease lesions, and can be reactivated in vitro by H. capsulatum Ags. T_H2 cells are relatively sparse at lesional sites. These studies support a general role for CD4⁺CTLs in inflammatory fibrosis and suggest that fibrosing mediastinitis is an Ag-driven disease that may provide important mechanistic insights into the pathogenesis of idiopathic fibrotic diseases.

Treatment of Congenital and Acquired Pulmonary Vein Stenosis

PURPOSE OF REVIEW

Pulmonary vein stenosis (PVS) is a rare entity that until the last 2 decades was seen primarily in infants and children. Percutaneous and surgical interventions have limited success due to relentless restenosis, and mortality remains high. In adults, acquired PVS following ablation for atrial fibrillation has emerged as a new syndrome. This work will review these two entities with emphasis on current treatment.

RECENT FINDINGS

Greater emphasis on understanding and addressing the mechanism of restenosis for congenital PVS has led to the use of drug-eluting stents (DES) and systemic drug therapy to target neo-intimal growth. Frequent reinterventions are positively affecting outcomes. Longer-term outcomes of percutaneous treatment for acquired PVS are emerging. Treatment of congenital PVS continues to be plagued by restenosis. DES show promise, but frequent reinterventions are required. Larger upstream vein diameter predicts success for congenital and acquired PVS interventions. Efforts to induce/maintain vessel growth are important for future treatment strategies.

Balloon angioplasty or stent implantation for pulmonary vein stenosis caused by fibrosing mediastinitis: a systematic review

Fibrosing mediastinitis (FM) is a very rare disease, often caused by histoplasmosis capsulatum, tuberculosis, sarcoidosis, autoimmunity and other diseases, such as IgG 4-related diseases. Fibrous structures in the mediastinum compress the pulmonary artery, pulmonary vein, superior vena cava, esophagus, trachea and cardiac vessels, leading to clinical symptoms. Drug therapeutic modality for pulmonary vein stenosis (PVS) caused by FM is palliative in essence and with limited efficacy, whereas surgical treatment causes high mortality. In recent years, catheter-based treatment to FM-caused PVS has emerged as a promising therapeutic modality, however, the safety and effectiveness of this modality remain unclear. Therefore, a systematic review on the safety and efficacy of the catheter-based treatment for PVS caused by FM was performed, in the hope to shed lights on the alternative therapeutic strategy to this fatal disease.

Catheter based treatments for fibrosing mediastinitis

Fibrosing mediastinitis is a rare, often debilitating and potentially lethal disease characterized by an exuberant fibroinflammatory response within the mediastinum. Patients typically present with insidious symptoms related to compression of adjacent structures including the esophagus, heart, airways, and cardiac vessels. Fibrosing mediastinitis is most often triggered by Histoplasmosis infection; however, antifungal and anti-inflammatory therapies are largely ineffective. While structural interventions aimed at alleviating obstruction can provide significant palliation, surgical interventions are challenging with high mortality and clinical experience with percutaneous interventions is limited. Here, we will review the presentation, natural history, and treatment of fibrosing mediastinitis, placing particular emphasis on catheter-based therapies.

Recurrent Pneumonia due to Fibrosing Mediastinitis in a Teenage Girl: A Case Report with Long-Term Follow-Up

A teenage girl was evaluated for recurrent right pneumonia. The evaluation revealed a calcified mediastinal mass that compressed the right intermediate and middle lobar bronchi, as well as the right pulmonary artery and veins. The clinical picture together with imaging studies and borderline positive serology testing suggested a diagnosis of fibrosing mediastinitis associated with histoplasmosis. This rare condition is characterized by the local proliferation of invasive fibrous tissue within the mediastinum due to a hyperimmune reaction to Histoplasma capsulatum. Antifungal and anti-inflammatory therapies are usually ineffective, and surgical intervention contains a high morbidity risk. Palliative surgery and stenting of the compressed airway have been suggested. In the past, the prognosis was thought to be poor, but recent studies demonstrate a more positive outcome. Our patient had been radiologically and functionally stable under follow-up for over thirteen years and has married and delivered two healthy children, both following an uneventful pregnancy.