Liver Fibrosis

Introduction

Any hepatic injury of a moderate degree or more, is going to cause a degree of fibrosis when the lesion has resolved. Fibrosis occurs due to proliferation of the supportive connective tissue in the liver. Fibrosis isolates the liver cells by effectively changing the sinusoids into capillaries and when a certain amount of fibrosis occurs, it can be self-perpetuating, the end result is a small scarred liver with functional failure.

Types of fibrosis

Periacinar fibrosis

In this type of fibrosis, the fibrous area surrounds the hepatic venule (centrilobular vein). This can be seen when there is chronic passive congestion with atrophy of the surrounding periacinar hepatocytes and condensation of the remaining connective tissue.

Biliary fibrosis

This usually occurs along with another type of fibrosis and will accompany inflammation centered on the portal triads.

Post necrotic scarring

This type of fibrosis occurs following massive necrosis where the necrotic cells are removed and the defect is repaired by fibrosis. It is seen histopathologically as bands of fibrous tissue.

Diffuse fibrosis

This occurs after repeated damage to one or more zones. The fibrosis generated proliferates throughout to involve all the tissue.

References

Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition), Elsevier Science.
Ettinger, S.J. and Feldman, E. C. (2000)Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition), W.B. Saunders Company.
Smyth, B (2008) Alimentary System Study Guide, Royal Veterinary College.