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 HYPERTENSIONClinical 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 HYPERTENSIONClinical 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 arteriopathyMedial hypertrophy, isolated or with intimal proliferation, concentric laminar, eccentric, adventitial fibrosis, plexifiorm and / or dilatation lesions, arteritis

• Pulmonary occlusive venopathy

• Pulmonary Microvasculopathy

PULMONARY HYPERTENSIONPathological 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’SWEGENER’S

Multifocal ischaemicnecrosis has resultedin numerous cavitating lesionsscattered throughout upper and lower lobesof left lung.

Dark haemorrhagiclung parenchyma between the cavities tothe 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