CVC LUNG, LIVER AND SPLEEN -Dr Sowmya Srinivas

HYPEREMIA & CONGESTION Hyperemia is an increase in volume of blood in a particular tissue. Its an “active process” , the increased blood influx results from arteriolar dilatation. Congestion, also known as “passive hyperemia”, results due to stagnation of blood because of venous obstruction.

Normal Figure 4-3 Hyperemia versus congestion. In both cases there is an increased volume and pressure of blood in a given tissue with associated capillary dilation and a potential for fluid extravasation. Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM) © 2005 Elsevier

a. Active Hyperemia (arterial): is an active process resulting from increased arterial blood inflow because of arteriolar dilatation. - The affected tissue is reddened because of engorgement of tissues with oxygenated blood. b. Passive hyperemia (Congestion) is a passive process resulting from impaired venous outflow from a tissue. - The affected tissue has a red-blue color due to accumulation of deoxygenated blood.

ACTIVE HYPEREMIA Types: 1. Physiological: - Hyperemia in skeletal muscles during exercise ,in the gut following a meal. 2. Pathological: e.g. in acute inflammation.

Hyperemia In hyperemia, increased inflow leads to engorgement with oxygenated blood, resulting in erythema. Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM) © 2005 Elsevier

PASSIVE HYPEREMIA OR CONGESTION Definition: - Increase in venous blood in an organ as result of obstruction of venous outflow. - The veins, venules & capillaries in the organ become passively dilated (passive hyperemia). Types: a. Localized b. Generalized

Congestion In congestion, diminished outflow leads to a capillary bed swollen with deoxygenated venous blood and resulting in cyanosis. Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM) © 2005 Elsevier

Examples:- Hyperemia:- Inflammation Blushing – adrenergic stimulation Exercise – increased blood flow to the muscle. Congestion:- Obstruction of veins due to thrombi or backward pressure due to heart failure.

Color of hyperemic & congested tissue:- Hyperemic tissue contains increased amounts of oxygenated blood & therefore the tissue appears bright red. Congested tissue contains increased amounts of deoxygenated blood & appears blue. Hyperemic tissue is warm, while congested blood is cold & clammy.

Chronic venous congestion (CVC):- In CVC there is long standing accumulation of deoxygenated blood & hence there is damage to the tissue.

Mechanism Pressure into pressure into the HEART FAILURE left heart failure right heart failure Pressure into pressure into the Pulmonary vein systemic venous system CVC LUNGS CVC LIVER SPLEEN KIDNEY

CVC Lung Causes:- Left heart failure Gross :- The lungs are heavy. Lungs appear brown- BROWN INDURATION OF LUNGS.

CVC Lungs Micro:- Rupture of congested vessel results in edema & hemorrhage. The alveolar septa appears thickened and fibrotic. The alveoli are dilated and contain edema fluid and RBC’s and macrophages. Lysis of RBC’s releases hemosiderin pigment which is taken up by macrophages in the alveoli – HEART FAILURE CELLS.

View of pulmonary congestion and edema View of pulmonary congestion and edema. Often caused by an increase in hydrostatic pressure, a protein poor transudate seeps into interstitial and alveolar spaces. Note the engorged alveolar wall capillaries. If capillaries rupture, RBCs will escape into the alveolar space

Heart failure cells are hemosiderin laden macrophages Heart failure cells are hemosiderin laden macrophages. Blood escapes into the alveolar space because chronic congestion causes the thin walled alveolar capillaries to burst. Note the thickening of the alveolar septae. This is caused by chronic pulmonary congestion and edema. Note the thickening of the alveolar septae. This is caused by chronic pulmonary congestion and edema.

CVC Liver Causes:- Right heart failure Occlusion of inferior vena cava or portal vein. GROSS APPEARANCE:- NUTMEG APPEARANCE – Alternate areas of red & yellow .

Nutmeg liver compared with actual nutmeg. Courtesy of Dr. Ed Friedlander

CVC Liver (MICRO) Blood fills up the central vein & sinusoids around it. Followed by centrilobular hepatocyte atrophy and necrosis. In the long standing cases the necrotic area is replaced by fibrous tissue. The mid zonal hepatocytes may show fatty change due to relative hypoxia. The areas with blood appears red & areas with fibrosis appears whitish yellow- NUTMEG APPEARANCE.

This view shows a close up of hemorrhagic central necrosis This view shows a close up of hemorrhagic central necrosis. Necrotic cells in the central area have been removed (cell dropout) and been replaced by cellular debris and hemorrhge. There is evidence that the passive congestion and hemorrhage is chronic, as many of the RBCs have been degraded into hemosiderin.

CVC Spleen Causes:- Right heart failure Portal hypertension GROSS:- Spleen is enlarged & congested.

CVC Spleen (micro) Red pulp appears congested. GAMMA GANDY BODIES OR SIDEROFIBROTIC NODULES:- Deposits of hemosiderin & calcium salts on fibrous tissue.

Gamma gandy bodies

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