Portal Hypertension, C53 P357-363 Flashcards
Identify the anatomy of the
portal venous system:
P357 (picture)
- Portal vein
- Coronary vein
- Splenic vein
- IMV (inferior mesenteric vein)
- SMV (superior mesenteric vein)
- Superior hemorrhoidal vein
Describe drainage of
blood from the superior
hemorrhoidal vein.
P358
To the IMV, the splenic vein, and then
the portal vein
Where does blood drain into
from the IMV?
P358
Into the splenic vein
Where does the portal vein
begin?
P358
At the confluence of the splenic vein and
the SMV
What are the (6) potential routes of portal–systemic collateral blood flow (as seen with portal hypertension)? P358
- Umbilical vein
- Coronary vein to esophageal venous
plexuses - Retroperitoneal veins (veins of Retzius)
- Diaphragm veins (veins of Sappey)
- Superior hemorrhoidal vein to middle
and inferior hemorrhoidal veins and
then to the iliac vein - Splenic veins to the short gastric
veins
What is the pathophysiology
of portal hypertension?
P358
Elevated portal pressure resulting from
resistance to portal flow
What level of portal
pressure is normal?
P358
<10 mm Hg
What is the etiology?
P358
Prehepatic—Thrombosis of portal vein/ atresia of portal vein Hepatic—Cirrhosis (distortion of normal parenchyma by regenerating hepatic nodules), hepatocellular carcinoma, fibrosis Posthepatic—Budd-Chiari syndrome: thrombosis of hepatic veins
What is the most common
cause of portal hypertension
in the United States?
P358
Cirrhosis (>90% of cases)
How many patients with
alcoholism develop
cirrhosis?
P358
Surprisingly, < 1 in 5
What percentage of patients
with cirrhosis develop
esophageal varices?
P359
≈40%
How many patients with
cirrhosis develop portal
hypertension?
P359
Approximately two thirds
What is the most common
physical finding in patients
with portal hypertension?
P359
Splenomegaly (spleen enlargement)
What are the associated
CLINICAL findings in
portal hypertension (4)?
P359 (picture)
- Esophageal varices
- Splenomegaly
- Caput medusae (engorgement of
periumbilical veins) - Hemorrhoids
What other physical findings
are associated with cirrhosis
and portal hypertension?
P359
Spider angioma, palmar erythema,
ascites, truncal obesity and peripheral
wasting, encephalopathy, asterixis (liver
flap), gynecomastia, jaundice
What is the name of the
periumbilical bruit heard
with caput medusae?
P359
Cruveilhier-Baumgarten bruit
What constitutes the portal– systemic collateral circulation in portal hypertension in the following conditions: Esophageal varices? P360
Coronary vein backing up into the
azygous system
What constitutes the portal– systemic collateral circulation in portal hypertension in the following conditions: Caput medusae? P360
Umbilical vein (via falciform ligament) draining into the epigastric veins
What constitutes the portal– systemic collateral circulation in portal hypertension in the following conditions: Retroperitoneal varices? P360
Small mesenteric veins (veins of Retzius)
draining retroperitoneally into lumbar veins
What constitutes the portal– systemic collateral circulation in portal hypertension in the following conditions: Hemorrhoids? P360
Superior hemorrhoidal vein (which
normally drains into the inferior mesenteric
vein) backing up into the middle
and inferior hemorrhoidal veins
What is the etiology?
P360
Cirrhosis (90%), 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 North America?
P360
Schistosomiasis
What is Budd-Chiari
syndrome?
P360
Thrombosis of the hepatic veins
What is the most feared
complication of portal
hypertension?
P360
Bleeding from esophageal varices
What are esophageal
varices?
P360
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?
P360
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 will 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? P361
Only ≈50% of the time
What are the signs/symptoms?
P361
Hematemesis, melena, hematochezia
What is the mortality rate
from an acute esophageal
variceal bleed?
P361
≈50%
What is the initial treatment
of variceal bleeding?
P361
As with all upper GI bleeding: large bore IVs x 2, IV fluid, Foley catheter, type and cross blood, send labs, correct coagulopathy (vitamin K, fresh frozen plasma), +/ – intubation to protect from aspiration
What is the diagnostic test
of choice?
P361
EGD (upper GI endoscopy)
Remember, bleeding is the result of
varices only half the time; must rule
out ulcers, gastritis, etc.
If esophageal varices cause
bleeding, what are the EGD
treatment options?
P361
- Emergent endoscopic
sclerotherapy: a sclerosing substance
is injected into the esophageal varices
under direct endoscopic vision - Endoscopic band ligation: elastic
band ligation of varices
What are the pharmacologic
options?
P361
Somatostatin (Octreotide) or IV
vasopressin (and nitroglycerin, to
avoid MI) to achieve vasoconstriction of the
mesenteric vessels; if bleeding continues,
consider balloon (Sengstaken-Blakemore
tube) tamponade of the varices, -blocker
What is a Sengstaken-
Blakemore tube?
P361
Tube with a gastric and esophageal
balloon for tamponading an esophageal
bleed (see page 268)
What is the next therapy after
the bleeding is controlled?
P361
Repeat endoscopic sclerotherapy/banding
What are the options if sclerotherapy and conservative methods fail to stop the variceal bleeding or bleeding recurs? P362
Repeat sclerotherapy/banding and treat conservatively TIPS Surgical shunt (selective or partial) Liver transplantation
What is a “selective” shunt?
P362
Shunt that selectively decompresses the
varices without decompressing the portal
vein
What does the acronym
TIPS stand for?
P362
Transjugular Intrahepatic Portosystemic
Shunt
What is a TIPS procedure?
P362
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”?
P362
Shunt that directly decompresses the
portal vein, but only partially
What is a Warren shunt?
P362 (picture)
Distal splenorenal shunt with ligation of the
coronary vein—elective shunt procedure
associated with low incidence of
encephalopathy in patients postoperatively
because only the splenic flow is diverted
to decompress the varices
What is a contraindication to
the Warren “selective”
shunt?
P363
Ascites
Define the following shunts:
End-to-side portocaval shunt
P363
“Total shunt”—portal vein (end) to IVC
side
Define the following shunts:
Side-to-side portocaval
shunt
P363
Side of portal vein anastomosed to side of
IVC—partially preserves portal flow
(“partial shunt”)
Define the following shunts:
Synthetic portocaval
H-graft
P363
“Partial shunt”—synthetic tube graft from the portal vein to the IVC (good option for patients with alcoholism; associated with lower incidence of encephalopathy and easier transplantation later)
Define the following shunts:
Synthetic mesocaval
H-graft
P363
Synthetic graft from the SMV to the IVC
What is the most common
perioperative cause of death
following shunt procedure?
P363
Hepatic failure, secondary to decreased
blood flow (accounts for two thirds of
deaths)
What is the major
postoperative morbidity
after a shunt procedure?
P363
Increased incidence of hepatic encephalopathy because of decreased portal blood flow to the liver and decreased clearance of toxins/metabolites from the blood
What medication is infused to counteract the coronary artery vasoconstriction of IV vasopressin? P363
Nitroglycerin IV drip
What lab value roughly
correlates with degree of
encephalopathy?
P363
Serum ammonia level (Note: Thought
to correlate with but not cause
encephalopathy)
What medications are used to
treat hepatic encephalopathy?
P363
Lactulose PO, with or without
neomycin PO