What is segmental arterial Mediolysis?
Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly.
What is segmental arteritis?
Segmental arterial mediolysis (SAM) is a rare but serious nonatherosclerotic, noninflammatory vasculopathy of un-known etiology. It is characterized by lysis of the medial layer of the arterial wall, often resulting in dissection, aneurysm, occlusion, or stenosis.
How rare is segmental arterial Mediolysis?
Epidemiology. Since it was first reported in 1976 there have been 101 documented cases of Segmental Arterial Mediolysis. Although typically seen in older patients with an average age of 57 years old, it can affect patients of any age and does not favor one gender or the other.
What causes segmental arterial Mediolysis?
Does polyarteritis nodosa go away?
After diagnosis, patients are treated with high doses of corticosteroids. Other immunosuppressive drugs are also added for patients who are especially ill. In most cases of PAN now, if diagnosed early enough the disease can be controlled, and often cured.
What is a splanchnic artery?
The splanchnic circulation consists of the blood supply to the gastrointestinal tract, liver, spleen, and pancreas. It consists of two large capillary beds partially in series. The small splanchnic arterial branches supply the capillary beds, and then the efferent venous blood flows into the PV.
What is meant by splanchnic vasodilation?
Splanchnic vasodilation is responsible for the hypoperfusion of the renal system which leads to the activation of the renin-angiotensin-aldosterone system and to fluid retention. Diuretics are the pivotal drugs in the control of ascites.
How does splanchnic vasodilation cause portal hypertension?
An increase in splanchnic blood flow in portal hypertension is the result of a marked vasodilation of arterioles in splanchnic organs, which drain blood into the portal venous system[35].
What are the three splanchnic nerves?
Thoracic splanchnic nerves (greater, lesser, and least) Lumbar splanchnic nerves. Sacral splanchnic nerves.
Are splanchnic nerves sympathetic or parasympathetic?
Splanchnic nerves are bilateral visceral autonomic nerves. The thoracic, lumbar and sacral splanchnic nerves are sympathetic in function while the pelvic splanchnic nerves are parasympathetic. These nerves have connections to the celiac, aortic, mesenteric, hypogastric and pelvic plexuses.
How does propranolol decrease portal hypertension?
Propranolol is a noncardioselective beta-blocker that reduces portal pressure through the reduction of portal and collateral blood flow. It competes with adrenergic neurotransmitters (eg, catecholamines) at sympathetic receptor sites.
Is the vagus nerve A splanchnic nerve?
In contrast to the vagus nerve, most fibers present in the splanchnic nerves are motor or efferent (80–90%). These nerve fibers travel along the branches of the vagus nerve and blood vessels to get to the wall of esophagus.