Aneurysmen der Visceralarterien

Visceral artery aneurysms are abnormal focal dilatations of arteries supplying abdominal organs. Visceral artery aneurysms include both true aneurysms and pseudoaneurysms.

Owing to different clinical manifestations and a unique, specific, pathology, renal artery aneurysms are discussed separately.

Epidemiology

The reported incidence of visceral artery aneurysms is approximately 0.01% to 2% on autopsy and angiographic studies , with over half the cases involving splenic artery aneurysms.

Clinical presentation 

Most patients are asymptomatic and these aneurysms are usually discovered incidentally. Less frequently they are associated with abdominal pain or are palpable as a pulsatile mass in the abdomen.

Up to 25% may be complicated by rupture . In these cases, patients present with acute abdominal pain and bleeding that is associated with a high rate of morbidity and mortality .

Pathology

Etiology

Visceral artery aneurysms are usually degenerative and related to a deficiency of the arterial media with loss of elastic fibers and reduced smooth muscle. Other possible causes are atherosclerosis, fibromuscular dysplasia, collagen disorders, trauma, inflammation, infection, or vasculitis . Pancreatitis may promote the destruction of the arterial wall resulting in pseudoaneurysms of related visceral arteries. Segmental arterial mediolysis is also an increasingly recognized cause.

Distribution

Multiple aneurysms are present in approximately one-third of the cases . The distribution among visceral arteries is :

Treatment and prognosis

Follow-up and treatment recommendations vary somewhat for different types of visceral artery aneurysms, and are discussed in more detail in their respective articles.

In general, treatment for visceral artery aneurysms is generally recommended when they are >2 cm in diameter.

Follow-up recommendations some types of visceral artery aneurysms is not established. Patients with pancreaticoduodenal aneurysms (e.g. post-Whipple procedure patients) are thought to be at higher risk of rupture than other visceral artery aneurysms. If the aneurysm is thought to be a pseudoaneurysm, it would probably be prudent to have a shorter follow-up interval.

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