VASCULAR DISORDERS OF THE LUNG PULMONARY OEDEMA PULMONARY EMBOLI / INFARCT PULMONARY HYPERTENSION PULMONARY HAEMORRHAGE & VASCULITIS

PULMONARY EMBOLI / INFARCT PE – most common preventable cause of death in hospitalized patients Embolus: A detached intravascular solid, liquid or gaseous mass that is carried by the blood to a site distant from its point of origin 99% of all emboli are thromboemboli Rarer – bone, marrow, atheroma, fat, tumour, FBs [ cotton, cardiac catheter, talc (ivdu)], parasites, amniotic fluid 95% PE arise in thrombi in large deep veins of LL What happens depends on size:occlude main PA, lodge at bifurcation = saddle embolus, shower of smaller emboli may travel distally, passage thru ASD/VSD = “paradoxical embolus”

Most PEs are small and silent Respiratory & haemodynamic compromise If > 60% of total pulmonary vasculature obstructed - sudden death, acute RHF, EMD Middle size arteries – haemorrhage Obstruction of smaller Pul. Aa branches (end arteries) - infarction PE leading to infarction uncommon in young – but is seen where circulation already inadequate – heart & lung disease Chronically - Pulmonary hypertension, R heart strain PULMONARY EMBOLI / INFARCT

Acute thromboemboli - blood, fibrin, platelets, neutrophils arranged in alternating linear zones – Lines of Zahn After 2-3 days – organization, ingrowth of fibroblasts, capillaries from vessel wall Thrombus is replaced by fibrosis and small vascular spaces – recanalization PULMONARY EMBOLI / INFARCT

¾ infarcts affect the lower lobes Not usually excised – unless clinically unsuspected e.g. unresolving infiltrate or nodular opacity Classically a wedge shape with base on pleural surface Central bland necrosis with ghosts of lung architecture, haemorrhage, active fibroblasts at edge, squamous metaplasia, reactive atypia Eventually a fibrous scar Consider causes other than simple TE PULMONARY EMBOLI / INFARCT

PULMONARY HYPERTENSION Mean pulmonary artery pressure >25mmHg at rest, > 30mmHg during exercise Elevated pressure is related to high pulmonary vascular resistance due to obstruction of small arteries 3 factors contribute to small pulmonary artery obstruction: vasoconstriction, cellular proliferation & fibrosis and thrombosis Reclassification at Venice 2003

Pulmonary arterial hypertension Pulmonary hypertension with left heart disease Pulmonary hypertension with lung diseases / hypoxaemia Pulmonary hypertension due to chronic TE disease PULMONARY HYPERTENSION Clinical Classification

PRIMARY PULMONARY HYPERTENSION Primary plexiform arteriopathy Young women (20-40 years) Dyspnoea & fatigue, some chest pain Progression to resp distress, RVH and cor pulmonale Rx – vasodilators, anticoagulants, prostacyclins

SECONDARY PULMONARY HYPERTENSION Cardiac disease Obstruction of main Pulmonary Veins Chronic embolic disease Lung disease Alveolar hypoxia Liver disease, portal hypertension HIV infection Ingestants / inhalants Collagen vascular disease

Pulmonary arterial hypertension Pulmonary hypertension with left heart disease Pulmonary hypertension with lung diseases / hypoxaemia Pulmonary hypertension due to chronic TE disease PULMONARY HYPERTENSION Clinical Classification

PULMONARY HYPERTENSION Heath and Edwards Grades I medial hypertrophy II intimal proliferation – mild III intimal fibrosis – moderate IV plexiform or dilatation lesions, necrotizing arteritis – severe

Pulmonary arteriopathy Medial hypertrophy, isolated or with intimal proliferation, concentric laminar, eccentric, adventitial fibrosis, plexifiorm and / or dilatation lesions, arteritis Pulmonary occlusive venopathy Pulmonary Microvasculopathy PULMONARY HYPERTENSION Pathological classification – Venice 2003

PULMONARY HAEMORRHAGE & VASCULITIS ALVEOLAR HAEMORRHAGE SYNDROMES Goodpasture’s syndrome = Antibasement membrane disease Idiopathic pulmonary haemosiderosis (IPH) Wegener’s granulomatosis (WG) CVD esp. acute Lupus Drugs, inhalants Idiopathic RPGN SECONDARY ALVEOLAR HAEMORRHAGE LOCALIZED HAEMORRHAGE

WEGENER’S GRANULOMATOSIS (WG) TRIAD Granulomatous inflammmation of URT & LRT Generalized vasculitis Glomerulonephritis LUNG most frequently affected Middle aged adults – but wide age range Fever, malaise, wt loss, cough, chest pain, hemoptysis, renal failure, anaemia, sinusitis Radiology – multiple lung masses resembling mets or cavitating abscesses Serology – Antineutrophil cytoplasmic antibodies (ANCA)

WEGENER’S Multifocal ischaemic necrosis has resulted in numerous cavitating lesions scattered throughout upper and lower lobes of left lung. Dark haemorrhagic lung parenchyma between the cavities to the upper right

ANCA - fluorescent microscopy C-ANCA, diffuse granular cytoplasmic staining pattern in WG P-ANCA, perinuclear staining pattern in microscopic polyangiitis

WG in the LUNG Necrotizing granulomatous inflammation Necrotizing vasculitis Large geographic areas of necrosis (dirty / basophilic / blue under the microscope) Microabscesses – neutrophils MNGCs Ddx: mycobacterial & fungal infection

VASCULAR DISORDERS OF THE LUNG PULMONARY OEDEMA PULMONARY EMBOLI / INFARCT PULMONARY HYPERTENSION PULMONARY HAEMORRHAGE & VASCULITIS