LVD

1. 27 July 2023 1
LUNG VASCULAR
DISEASES
MWAKIGONJA, Amos Rodger: MD, MMed, PhD,
FCPath ECSA
Consultant Pathologist & Senior Lecturer
School of Medicine (SoM)
MUHAS

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Introduction
 Diseases of the heart affect the lungs &
vice versa.
 Pressure in pulmonary arteries is
lower<systemic.
 Pulmonary arteries thinner than systemic
 Elastic vessels

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Introduction
 Generally pulmonary vascular d’ses are:
 Pulmonary oedema
 Pulmonary congestion
 Pulmonary thrombosis
 Pulmonary embolism
 Pulmonary infarction
 Specific forms
 Adult respiratory distress syndrome (ARDS)
 Pulmonary hypertension

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Pulmonary oedema
 Can result from
 elevated pulmonary hydrostatic pressure
 Increased capillary permeability
1. Elevated pulmonary hydrostatic
pressure:
 Heart failure (LVF), MS, pul vein obstr,
thyrotoxicosis:
 incr. Pressure in pulmonary veins, interstitial
oedema, alveolar destruction, alveolar
oedema.

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Pulmonary oedema
2. Irritant oedema:
 Incr. Vascular permeability due to damage
 Infections, toxins, aspiration, shock,
radiation, hypersensitivity, uraemia, ARDS.
3. Acute high altitude oedema:
 Sudden climb >2500m, oedema, congestion,
haemorrhages
 Anoxic damage to pulmonary vessels.

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Pulmonary congestion
 Chronic venous congestion of lung
 LVH, MS
 Interstitial oedema, dilated, congested
capillaries,
 +/- rupture=minute haemorrhages
 Heart failure cells

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Pulmonary thromboembolism
 Most c’mon, fatal venous thromboembolism
 Pulmonary thrombosis is unc’mon, due to
atherosclerosis, PHT
 Etiology:
 Prolonged immobilization-hospitalization,
 DVT-long flights
 Varicosities
 Saddle embolus, multiple, paradoxical

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Pulmonary thromboembolism
 Consequences
 Depends on size of vessel, number of emboli,
CVS status
 Sudden death
 Acute cor pulmonale
 Haemorrhage
 Resolution
 PHT, chronic cor pulmonale, pulmonary
arteriosclerosis.

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Pulmonary infarction
 May result from pulmonary embolism.
 Lungs have double circulation.
 Often in lower lobes, on base of pleura
 Fibrinous pleuritis
 Coagulative necrosis of alveolar walls
 Neutrophils, vasocongestion
 Later haemosiderin, phagocytes,
granulation

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ARDS
 Also shock-lung syndrome, diffuse alveolar
damage (DAD), acute alveolar injury,
traumatic wet lungs, post-traumatic
respiratory insufficiency.
 Caused by diffuse alveolar damage
 Sudden & severe resp distress,
tachypnoea, tachycardia, cyanosis, failure
to respond to oxygen therapy unlike
neonatal RDS.

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ARDS
 Causes:
 Shock due to sepsis, trauma, burns
 Diffuse pulmonary infxns esp viral
 Pancreatitis
 Oxygen toxicity
 Inhalation of toxins & irritants
 Narcotics overdose
 Drugs eg salicylates, colchicine
 Aspiration
 Fat embolism
 Radiation

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Pulmonary hypertension
 Primary or idiopathic
 Secondary to lesions in heart or lungs
