Portal Hypertension Flashcards
Describe the drainage of blood from the superior hemorrhoidal vein.
To the IMV, the splenic vein, then the portal vein
Where does blood grain into from the IMV?
Into the splenic vein
Where does the portal vein begin?
At the confluence of the splenic vein and the SMV
What are the 6 potential routes of portal-systemic collateral blood flow?
- Umbilical vein
- Coronary vein to esophageal varices
- Retroperitoneal veins (veins of Retzius)
- Diaphragm veins (veins of Sappey)
- Superior hemorrhoidal vein to middle and inferior hemorrhoidal veins and then iliac vein
- Splenic veins to the short gastric veins
What is the pathophysiology of portal hypertension?
Elevated portal pressure resulting from resistance to portal flow
What level of portal pressure is normal?
< 10 mmHg
What is the etiology of portal hypertension?
- Prehepatic (e.g. thrombosis of portal vein, atresia of portal vein)
- Hepatic (e.g. distortion of normal parenchyma, hepatocellular carcinoma)
- Posthepatic (e.g. Budd-Chiari syndrome, thrombosis of hepatic veins)
What is the most common cause of portal hypertension in the US?
Cirrhosis
How many patients with alcoholism develop cirrhosis?
< 20%
What percentage of patients with cirrhosis develop esophageal varieces?
40%
How many patins with cirrhosis develop portal hypertension?
66%
What is the most common physical finding in patients with portal hypertension?
Splenomegaly
What are the 4 associated clinical findings in portal hypertension?
- Esophageal varices
- Splenomegaly
- Caput medusae
- Hemorrhoids
What is the name of the periumbilical bruit heard with caput medusae?
Cruveilhier-Baumgarten bruit
What is the portal-systemic collateral circulation involved in esophageal varices?
Coronary vein backing up into the azygous system
What is the portal-systemic collateral circulation involved in caput medusae?
Umbilical vein draining into the epigastric veins
What is the portal-systemic collateral circulation involved in retroperitoneal varices?
Small mesenteric veins (veins of Retzius) draining retroperitoneally into lumbar veins
What is the portal-systemic collateral circulation involved in hemorrhoids?
SVC backing up into the middle and inferior hemorrhoidal veins
What are possible causes of portal hypertension?
Cirrhosis, schistosomiasis, hepatitis, Budd-Chiari syndrome, hemochromatosis, Wilson’s disease, portal vein thrombosis, tumors, splenic vein thrombosis
What is the most common cause of portal hypertension outside of the US?
Schistosomiasis
What is Budd-Chiari syndrome?
Thrombosis of the hepatic veins
What is the most feared complication of portal hypertension?
Bleeding from esophageal varices
What are esophageal varices?
Engorgement of the esophageal venous plexuses secondary to increased collateral blood flow from the portal system as a result of portal hypertension
What is the “rule of 2/3” of portal hypertension?
2/3 of patients with cirrhosis will develop portal hypertension.
2/3 of patients with portal hypertension will develop esophageal varices.
2/3 of patients with esophageal varices with bleed from the varices.
In patients with cirrhosis and known varices who are suffering from upper GI bleeding, how often does that bleeding result from varices?
50%
What are the signs and symptoms of esophageal varices?
Hematemesis, melena, hematochezia
What is the mortality rate from an acute esophageal variceal bleed?
50%
What is the initial treatment of variceal bleeding?
2 large bore IVs; IVF; Foley; T&C; labs; correct coagulopathy (vit K, FFP), +/- intubation
What is the diagnostic test of choice for esophageal varices?
EGD
If esophageal varices cause bleeding, what are the EGD treatment options?
- Emergent endoscopic sclerotherapy
2. Endoscopic band ligation
What is endoscopic sclerotherapy?
Injection of sclerosing substance into esophageal varices under direct endoscopic vision
What are the pharmacologic options for esophageal varices?
Somatostatin or IV vasopressin (and nitroglycerin); if bleeding continues: Sengstaken-Blakemore tube, beta-blockers
What is a Sengstaken-Blakemore tube?
Tube with a gastric and esophageal balloon for tamponading an esophageal bleed
What is the next therapy after the bleeding from esophageal varices is controlled?
Repeat endoscopic sclerotherapy or banding
What are the options if sclerotherapy and conservative methods fail to stop variceal bleeding or bleeding recurs?
- Repeat sclerotherapy or banding and treat conservatively
- TIPS
- Surgical shunt (selective or partial)
- Liver transplant
What is a selective shunt, as used in the treatment of esophageal varices?
Shunt that selectively decompresses the varices without decompressing the portal vein
What is TIPS?
Transjugular Intrahepatic Portosystemic Shunt
What is a TIPS procedure?
Angiographic radiologist places a small tube stent intrahepatically between the hepatic vein and a branch of the portal vein via a percutaneous jugular vein route
What is a partial shunt, as used in the treatment of esophageal varices?
Shunt that directly decompresses the portal vein, but only partially
What is a Warren shunt?
Distal splenorenal shunt with ligation of the coronary vein.
Elective shunt procedure associated with low incidence of encephalopathy in patients post-op because only the splenic flow is diverted to decompress the varices
What is the contraindication to the Warren shunt?
Ascites
What is an end-to-side portocaval shunt?
A total shunt: portal vein (end) to IVC (side)
What is a side-to-side portocaval shunt?
Side of the portal vein is anastomosed to side of the IVC, partially preserving portal flow
What is a synthetic portocaval shunt?
A partial shunt: synthetic tube graft from the portal vein to the IVC
What is a synthetic mesocaval shunt?
A synthetic graft from the SMV to the IVC
What is the most common perioperative cause of death following a hepatic shunt procedure?
Hepatic failure secondary to decreased blood flow
What is the major postoperative morbidity after a hepatic shunt procedure?
Increased incidence of hepatic encephalopathy because of decreased portal blood flow to the liver and decreased clearance of toxins and metabolites from the blood
What medication is infused to counteract the coronary artery vasoconstriction of IV vasopressin?
Nitroglycerin IV drip
What lab value roughly correlates with degree of hepatic encephalopathy?
Serum ammonia level
What medications are used to treat hepatic encephalopathy?
Lactulose PO, +/- neomycin PO
