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Category:Liver - Circulatory Disturbances (view source)
Revision as of 12:14, 7 June 2010
, 12:14, 7 June 2010Created page with '==Telangiectasis== Portosystemic Shunting ==Passive congestion== Usually associated with right-sided heart failure because when the right side of …'
==[[Telangiectasis]]==
[[Portosystemic Shunt|Portosystemic Shunting]]
==Passive congestion==
Usually associated with right-sided heart failure because when the right side of the heart fails to function properly, blood will back up through the veins into the [[Liver - Anatomy & Physiology|liver]].
The appearances and changes in the [[Liver - Anatomy & Physiology|liver]] will depend on whether the conggestion is of short or long duration.
===Acute congestion===
*occurs in acute right-sided heart failure and in shock
====Gross====
*[[Liver - Anatomy & Physiology|liver]] is swollen and engorged with rounded edges to the lobes
*fibrin may be present on the surface, coming from the dilated subcapsular lymphatics
*blood oozes freely from the cut surface
*the sinusoids are dilated and packed with red blood cells
====Microscopically====
*hepatic venules and sinusoids engorged with blood
===Chronic congestion===
*occurs in chronic right-sided heart following on from left-sided heart failure eg endocardiosis in dogs, cardiomyopathy in cats [need link in future]
====Gross====
*slightly swollen with rounded edges
*capsular surface may be paler and thicker than normal
*alternating red and yellow areas on the cut surface: accentuates the acinar pattern
**this contrasting red and yellow mottled gross appearance (especially that of the formalin-fixed specimen) resembles the cut surface of a nutmeg, and is referred to as ''''nutmeg'''' [[Liver - Anatomy & Physiology|liver]]
**at this stage the [[Liver - Anatomy & Physiology|liver]] may have returned to normal size or be slightly smaller than normal
*fibrosis can develop in the congested centrilobular zones and the liver becomes firm to section, ie cardiac fibrosis
====Microscopically====
*the red areas are engorged and dilated hepatic venules which may show a substantial increase in perivenular fibrous tissue due to atrophy and loss of adjacent hepatocytes
*the yellowish areas are the midzonal and perhaps periportal hepatocytes in very long standing cases which have undegone fatty change due to hypoxia and malnutrition
*the Kuppfer cells may contain considerable haemosiderin pigment
**golden brown in H&E sections
**blue with Perls' Prussian blue stain (specific for haemosiderin)
==Thrombosis==
*uncommon total obstruction
===hepatic artery===
*will result in [[Liver - Anatomy & Physiology|liver]] necrosis
===portal vein===
*''no'' hepatic change
*will cause infarction of the intestine
*if prolonged, it will diminish the supply of nutrient to the [[Liver - Anatomy & Physiology|liver]] causing a reduction in organ size
NB: 70% of the blood supplied to the [[Liver - Anatomy & Physiology|liver]] is via the portal vein but the hepatic arterial blood is the most important for [[Liver - Anatomy & Physiology|liver]] cell survival
[[Category:Liver_-_Pathology]]
[[Portosystemic Shunt|Portosystemic Shunting]]
==Passive congestion==
Usually associated with right-sided heart failure because when the right side of the heart fails to function properly, blood will back up through the veins into the [[Liver - Anatomy & Physiology|liver]].
The appearances and changes in the [[Liver - Anatomy & Physiology|liver]] will depend on whether the conggestion is of short or long duration.
===Acute congestion===
*occurs in acute right-sided heart failure and in shock
====Gross====
*[[Liver - Anatomy & Physiology|liver]] is swollen and engorged with rounded edges to the lobes
*fibrin may be present on the surface, coming from the dilated subcapsular lymphatics
*blood oozes freely from the cut surface
*the sinusoids are dilated and packed with red blood cells
====Microscopically====
*hepatic venules and sinusoids engorged with blood
===Chronic congestion===
*occurs in chronic right-sided heart following on from left-sided heart failure eg endocardiosis in dogs, cardiomyopathy in cats [need link in future]
====Gross====
*slightly swollen with rounded edges
*capsular surface may be paler and thicker than normal
*alternating red and yellow areas on the cut surface: accentuates the acinar pattern
**this contrasting red and yellow mottled gross appearance (especially that of the formalin-fixed specimen) resembles the cut surface of a nutmeg, and is referred to as ''''nutmeg'''' [[Liver - Anatomy & Physiology|liver]]
**at this stage the [[Liver - Anatomy & Physiology|liver]] may have returned to normal size or be slightly smaller than normal
*fibrosis can develop in the congested centrilobular zones and the liver becomes firm to section, ie cardiac fibrosis
====Microscopically====
*the red areas are engorged and dilated hepatic venules which may show a substantial increase in perivenular fibrous tissue due to atrophy and loss of adjacent hepatocytes
*the yellowish areas are the midzonal and perhaps periportal hepatocytes in very long standing cases which have undegone fatty change due to hypoxia and malnutrition
*the Kuppfer cells may contain considerable haemosiderin pigment
**golden brown in H&E sections
**blue with Perls' Prussian blue stain (specific for haemosiderin)
==Thrombosis==
*uncommon total obstruction
===hepatic artery===
*will result in [[Liver - Anatomy & Physiology|liver]] necrosis
===portal vein===
*''no'' hepatic change
*will cause infarction of the intestine
*if prolonged, it will diminish the supply of nutrient to the [[Liver - Anatomy & Physiology|liver]] causing a reduction in organ size
NB: 70% of the blood supplied to the [[Liver - Anatomy & Physiology|liver]] is via the portal vein but the hepatic arterial blood is the most important for [[Liver - Anatomy & Physiology|liver]] cell survival
[[Category:Liver_-_Pathology]]