The role of thrombosis in severe pulmonary hypertension

440

350

Pulmonary arterial hypertension is a severe disease that has been ignored for a long time. However, over the past 20 yrs chest physicians, cardiologists and thoracic surgeons have shown increasing interest in this disease because of the development of new therapies, that have improved both the outcome and quality of life of patients, including pulmonary transplantation and prostacyclin therapy.Chronic thromboembolic pulmonary arterial hypertension (CTEPH) can be cured surgically through a complex surgical procedure: the pulmonary thromboendarterectomy. Pulmonary thromboendarterectomy is performed under hypothermia and total circulatory arrest.Due to clinically evident acute-pulmonary embolism episodes being absent in w50% of patients, the diagnosis of CTEPH can be difficult. Lung scintiscan showing segmental mismatched perfusion defects is the best diagnostic tool to detect CTEPH.Pulmonary angiography confirms the diagnosis and determines the feasability of endarterectomy according to the location of the disease, proximal versus distal. The technique of angiography must be perfect with the whole arterial tree captured on the same picture for each lung. The lesions must start at the level of the pulmonary artery trunk, or at the level of the lobar arteries, in order to find a plan for the endarterectomy.When the haemodynamic gravity corresponds to the degree of obliteration, pulmonary thromboendarterectomy can be performed with minimal perioperative mortality, providing definitive, excellent functional results in almost all cases. Pulmonary arterial hypertension is a severe disease that has been historically neglected. Over the past 20 yrs, chest physicians, cardiologists and thoracic surgeons have shown increasing interest in this disease because of the development of new therapies that have improved the outcome and quality of life of patients. Available options now include prostacyclin therapy, pulmonary endarterectomy and pulmonary transplantation.Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by obstruction of the large pulmonary arteries by acute and recurrent pulmonary emboli, and organisation of these blood clots. This disease, initially considered to be rare, is being diagnosed more and more frequently. A possible reason for this is the availability of successful medical and surgical treatment. The development of centres specialising in the diagnosis and treatment of pulmonary hypertension, and more consistent follow-up procedures for patients presenting with acute pulmonary emboli may also contribute to the ongoing increase in the number of patients diagnosed and treated for CTEPH. Pathogenesis or natural history of pulmonary emboliHaemodynamic failure and death occurs in 20-40% of patients within 1 h of acute pulmonary emboli [1]. Among survivors, the natural evolution, in most cases, is resorption of blood clots by local fibrinolysis with complete restoration of

Section: Cause Of Thrombi Formationsmentioning

confidence: 99%

Chronic thromboembolic pulmonary hypertension

Dartevelle¹,

Fadel²,

Mussot³

et al. 2004

440

350

“…An emerging role of release of platelet selective mediators, such as serotonin, thromboxane-A 2 and growth factors, in the development of CTEPH is under investigation [11]. It is not impossible that these factors may also induce changes in the adjacent lymph nodes.…”

Section: Discussionmentioning

confidence: 99%

Chronic thromboembolic pulmonary hypertension and vascular transformation of the lymph node sinuses

Meysman

Diltoer²,

Raeve³

et al. 1997

Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease often not recognized until it is far advanced. Medical management does not reverse the effects of the disease, nor does it prevent its progression. Pulmonary thromboendarterectomy is the preferred treatment.We present the case of a patient in whom CTEPH was mistaken for an interstitial lung disease with mediastinal lymph node enlargement. The mediastinal lymph node enlargement was due to vascular transformation of the lymph node sinuses (VTS). This is an unusual case of chronic thromboembolic pulmonary hypertension with vascular transformation of the lymph node sinuses. Eur Respir J 1997; 10: 1191-1193 Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but potentially treatable cause of pulmonary hypertension. Unfortunately, there is often a delay in the diagnosis due to the fact that signs and symptoms are nonspecific in the majority of these patients. For this reason, CTEPH is frequently mistaken for other entities, such as chronic obstructive pulmonary disease, coronary artery disease, interstitial lung disease, congestive heart failure, or psychosomatic dyspnoea [1].We present the case of a patient in whom enlarged mediastinal lymph nodes and a mosaic pattern of lung attenuation on chest computed tomography (CT) scan were mistaken for interstitial lung disease. At autopsy, CTEPH and vascular transformation of the lymph node sinuses (VTS) were found. Case reportA 32 year old male was transferred to our institution because of respiratory distress and haemoptysis after transbronchial biopsy. Since the age of 10 yrs, the patient had been treated with inhaled β 2 -mimetics on demand, for allergic asthma. He had a smoking history of 15 pack-years but had ceased smoking 3 yrs before admission. Varicectomy of the lower limbs had been performed 2 yrs earlier.The patient was examined at another hospital a few months before admission because of worsening exertional dyspnoea and wheezing. Inhaled corticosteroids, budesonide 400 mg·day -1 , were added to his treatment, without any improvement in his symptoms. Spirometry performed at that time showed moderate obstructive pulmonary disease, with significant bronchial hypersensitivity at histamine provocation testing (provocative dose causing a 20% fall in forced expiratory volume in one second (PD20) 0.8 mg·mL -1 ). A chest radiograph was reported to show cardiac enlargement and pulmonary hyperinflation. An electrocardiogram revealed sinus rhythm with inverted T-waves in the precordial leads, and an echocardiogram demonstrated considerable enlargement of the right atrium and ventricle. Mean pulmonary artery pressure by Doppler evaluation of the tricuspid regurgitant envelope was estimated at 42 mmHg. A CT scan of the chest ( fig. 1a and b) revealed mediastinal lymph node enlargement and a mosaic pattern of lung attenuation, suggesting interstitial lung disease.Bronchoscopy and transbronchial biopsy were performed but haemoptysis and respiratory distress developed soon afterwards. The ...

“…Thrombosis of the pulmonary arteries is a very common complication of many varieties of PH [105]. For example, CALVERLY et al [106] found that~50% of patients with cor pulmonale due to respiratory failure had pulmonary artery thrombosis at post mortem.…”

Section: The Role Of Pulmonary Endarterectomymentioning

confidence: 99%

Is pulmonary embolism a common cause of chronic pulmonary hypertension? Limitations of the embolic hypothesis

Egermayer¹,

Peacock²

2000

151

Is pulmonary embolism a common cause of chronic pulmonary hypertension? Limitations of the embolic hypothesis. P Egermayer, A.J. Peacock. #ERS Journals Ltd 2000. ABSTRACT: The hypothesis that chronic thromboembolic pulmonary hypertension results from unresolved pulmonary embolism has strongly influenced the diagnosis and management of this disease since the 1960s. However, it is nearly impossible to induce chronic pulmonary hypertension in any animal species by means of repeated embolization of thrombotic material. The haemodynamic effects of thrombotic pulmonary embolism of different degrees of magnitude have also been studied in humans and there is little to suggest that chronic pulmonary hypertension is a likely long term outcome. Furthermore many conditions which predispose to venous thromboembolism do not appear to cause thromboembolic pulmonary hypertension. Other arteriopathic and atherosclerotic risk factors, are found in patients with chronic thromboembolic pulmonary hypertension, but not in those with venous thrombosis, suggesting that these may be unrelated conditions.Thrombosis in situ of the pulmonary arteries is common in severe pulmonary hypertension of any cause. Such thrombosis cannot usually be distinguished from pulmonary embolism. It is hypothesized that in situ thrombosis and pulmonary arteriopathy are common causes of vascular occlusion which is usually diagnosed as "chronic thromboembolic pulmonary hypertension" and that venous thromboembolism is unlikely to be a common cause of chronic pulmonary hypertension. It is further hypothesized that pulmonary embolism is seldom the sole cause of "chronic thromboembolic pulmonary hypertension". Eur Respir J 2000; 15: 440±448.