portal obstruction........

[attitbaskota]

Can u explain me why caput medusae that is usual manifestation of potral hypertension cannot be seen in potral obstruction??
waiting for for reply.
thanx

[CSF]

portal hypertension is the result of gradual portal obstruction, so obviously caput medusae is seen...

so where is the confusion? did you find that capute medusae is not caused by portal obstruction in any book?

The term Caput Medusae describes the appearance of distended and engorged umbilical veins which are seen radiating from the umbilicus across the abdomen to join systemic veins. It is a sign of severe portal hypertension with portal-systemic shunting through the umbilical veins. The name originates from the apparent similarity to Medusa's hair once Minerva had turned it into snakes.

[attitbaskota]

once i was in the library,i read a book,there was written that portal obstruction donot cause apperance of the caput medusae.reason was also there but now i forgot that.i only remeber there was something written abt anatomical position of liver and portal vein.i was confused too.so i asked here. portal obstruction causes portal hypertension so is it neccesary portal obstruction may have caput medusae??
if u have clear concept plz tell me.
i am eager to know abt this.thanx.

[Pal]

Caput medusae is the appearance of distended and engorged umbilical veins which are seen radiating from the umbilicus across the abdomen to join systemic veins.

Portal Vein Obstruction

Background: In the English literature, portal vein obstruction was first reported in 1868 by Balfour and Stewart, who described a patient presenting with an enlarged spleen, ascites, and variceal dilatation.

The vast majority of cases are due to primary thrombosis of the portal vein; most of the remaining cases are caused by malignant obstruction.

Pathophysiology: The portal vein forms at the junction of the splenic vein and the superior mesenteric vein behind the pancreatic head, and it can become thrombosed or obstructed at any point along its course. In cirrhosis and hepatic malignancies, the thromboses usually begin intrahepatically and spread to the extrahepatic portal vein. In most other etiologies, the thromboses usually start at the site of origin of the portal vein. Occasionally, thrombosis of the splenic vein propagates to the portal vein, most often resulting from an adjacent inflammatory process such as chronic pancreatitis.

The presence of caput medusae indicates posthepatic or intrahepatic portal hypertension because it forms by recanalization of the umbilical vein, which connects with the left hepatic branch of the portal vein. It should not be observed in isolated extrahepatic portal vein obstruction because the obstruction is below the origin of the umbilical vein.



Portal Hypertension

Background: Portal hypertension may be defined as a portal pressure gradient of 12 mm Hg or greater and is often associated with varices and ascites. Many conditions are associated with portal hypertension, of which cirrhosis is the most common cause.

The portal vein drains blood from the small and large intestines, stomach, spleen, pancreas, and gallbladder. The superior mesenteric vein and the splenic vein unite behind the neck of the pancreas to form the portal vein. The portal trunk divides into 2 lobar veins. The right branch drains the cystic vein, and the left branch receives the umbilical and paraumbilical veins that enlarge to form umbilical varices in portal hypertension. The coronary vein, which runs along the lesser curvature of the stomach, receives distal esophageal veins, which also enlarge in portal hypertension.

Pathophysiology: Two important factors exist in the pathophysiology of portal hypertension, vascular resistance and blood flow. Ohm law is V = IR, where V is voltage, I is current, and R is resistance. This can be applied to vascular flow, ie, P = FR, where P is the pressure gradient through the portal venous system, F is the volume of blood flowing through the system, and R is the resistance to flow. Changes in either F or R affect the pressure. In most types of portal hypertension, both the blood flow and the resistance to blood flow are altered.

Caput Medusae is seen in portal hypertension.

Classification of Portal Hypertension.

I guess you gusy will be clear now

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Originally Posted by Pal

[size=3][font=Times New Roman]Caput medusae is the appearance of distended and engorged umbilical veins which are seen radiating from the umbilicus across the abdomen to join systemic
I guess you gusy will be clear now

yeah i guess, hypertension and obstruction are not the same phenomenon.

[attitbaskota]

thanx for this pal.
so,hypertension and obstruction are not the same.right?if not then i got it.
keep it up guys.thanx