pulmonary veno-occlusive disease (PVOD)
Pulmonary veno-occlusive disease (PVOD) is considered an uncommon variant of primary pulmonary hypertension (PPH) that preferentially affects the postcapillary pulmonary vasculature. It is still controversial if this condition and pulmonary capillary haemangiomatosis (PCH) are varied expressions of the same condition or different entities.
Epidemiology
It is thought to account for ~5-10% of cases initially considered to be idiopathic PAH .
It is rare but can potentially affect all age groups with no geographic predilection. The majority of affected patients are under 50 years of age .
- in the pediatric population, both sexes are equally affected
- in the adult population, the ratio of male to female patients is approximately 2:1
Clinical presentation
Its presentation can be similar to other forms of pulmonary arterial hypertension such as progressive dyspnea, cough, fatigue and also hemoptysis.
Pulmonary capillary wedge pressure (PCWP) is usually normal due to patchy involvement. This is in contrast to the elevated pressures commonly obtained in patients with obstructed or stenotic larger pulmonary veins, mitral stenosis or left ventricular failure .
Pathology
It is characterized by extensive occlusion of pulmonary veins by fibrous tissue in a patchy distribution. This may be loose and edematous or dense and sclerotic .
Associations
PVOD is still considered an idiopathic disease but innumerable associated conditions have been reported in the medical literature, which include :
- connective tissue disease
- HIV infection
- sarcoidosis
- pulmonary Langerhans cell histiocytosis
- peripheral blood stem cell transplantation
- bone marrow transplantation
- after radiation therapy
- after chemotherapy
- including treatment with bleomycin, cisplatin, vincristine, carmustine, and mitomycin
A recent discovery has suggested a biallelic mutation in the EIF2AK4 gene as a cause of heritable form .
Radiographic features
In general, imaging features can be non-specific and a definitive diagnosis often requires a lung biopsy .
Plain radiograph
Usually demonstrates nonspecific features of pulmonary hypertension, such as an enlarged pulmonary trunk and main pulmonary arteries and prominent heart right chambers.
CT
Reported HRCT chest findings include :
- regions of ground-glass opacities, which can be
- diffuse multifocal
- perihilar
- patchy
- centrilobular : most cases
- smooth interlobular septal thickening
- mediastinal lymph node enlargement
- pleural effusions
- enlarged central pulmonary arteries
- mosaic pattern of lung attenuation
- normal caliber pulmonary veins
The normal appearances of the heart left chambers in the setting of these pulmonary findings favors that the transudation of fluid into the lung interstitium is possibly PVOD related.
Angiography (DSA)
PVOD pulmonary arteriographic findings include :
- enlarged central pulmonary arteries
- subtle narrowing of the distal arterial branches
- no arterial filling defects
- heterogeneous contrast blush in the parenchymal phase
- prolonged lung circulation time
- normal or small left atrium
Treatment and prognosis
Pulmonary veno-occlusive disease generally carries a poor prognosis (some report a 72% mortality at one year from diagnosis ). Lung transplantation is the treatment of choice .
It is important to note that vasodilators commonly used to treat patients with primary pulmonary hypertension, such as calcium-channel blockers , epoprostenol (PGI2) or prostacyclin can lead to disastrous outcomes (severe pulmonary edema) in patients with pulmonary veno-occlusive disease.
History and etymology
The first description of the condition is thought to have been first dreported by J Hora (German physician) et al. in 1934 . The term "pulmonary veno-occlusive disease" was thought to have been coined by Heath et.al in 1966 .
Differential diagnosis
Possible differential considerations include
- pulmonary capillary haemangiomatosis (PCH)
- idiopathic pulmonary arterial hypertension
- there is no thickening of the interlobular septa
- peripheral lung oligemia
- chronic pulmonary thromboembolism
- there is no thickening of the interlobular septa
- presence of vascular pruning
See also
Siehe auch:
- Pleuraerguss
- Langerhanszell-Histiozytose der Lunge
- Sarkoidose
- mosaikartige Verdichtungen der Lunge
- verdickte interlobuläre Septen
- pulmonale kapilläre Hämangiomatose
- primary pulmonary hypertension
- Venenverschlusskrankheit der Leber
und weiter:
Assoziationen und Differentialdiagnosen zu Venenverschlusskrankheit der Lunge:
