Notice in this picture the greenish material accumulated In the wall of a portal arteriole. The deposition may be concentric or patchy. Sulfated alcian blue stain. Click on picture to enlarge 3-Aneurysms. They may involve extra and intrahepatic arteries.
Extrahepatic aneurysms are more common.
They are rare. Sixty per cent are caused by polyarteritis nodosa and are radiographically detectable. They may rupture and bleed intraperitoneally or into the bile ducts. Very few dissecting aneurysms have been reported. In intra hepatic fistulae between hepatic artery and portal vein will cause portal hypertension.