•PH is defined as pathological increase in portal pressure which is usually expressed as portal pressure gradient (gradient between portal pressure & IVC pressure). PH is defined as an elevation of portal pressure above mm Hg is usually manifested by splenomegaly & bleeding from esophageal varices. (Normal portal pressure is 5-10 mmHg, Avg 7 mm Hg)
PATHOPHYSIOLOGY
•In general, PH is the result of combination of increased portal blood flow & increased portal resistance. The portal resistance is lowered by development of porto-systemic shunting. Through collaterals, the portal hypertension is manifested by increased in blood flow in the portal system by tachycardia. An increased in cardiac output (CO) & splanchnic vasodilatation. All these is an increase in total portal flow (hepatic & collaterals). The actual portal flow reaching the liver is reduced. The major pathological effect from portal hypertension occurs due to shunting of blood through collateral from venous system to the systemic circulation.
ETIOLOGY
•Portal vein thrombosis is the commonest (60%) cause in children. Portal hypertension. Portal HTN can be due to increased portal blood flow or due to increased resistance to flow.
A.Intrahepatic portal HTN :
1.Hepatocellular disease –
•Acute or chronic viral hepatitis, cirrhosis
•Wilson disease, α1-AT deficiency
•Glycogen storage disease type IV
•Hepatotoxicity – MTX, TPN
2.Biliary tract disease : Extrahepatic biliary atresia, Choledocal cyst Intrahepatic biliary paucity, cystic fibrosis
3.Post sinusoidal :
Budd-chiare syndrome Venoocclusive disease
4.Idiopathic portal HTN.
B.Extrahepatic portal HTN :
Portal vein agenesis, atresia, stenosis
PV thrombosis or cavernous transformation
Splenic vein thrombosis
Increased portal flow
Atriovenous fistula
CLINICAL FEATURE
•History
1.Relevant to cirrhosis or chronic hepatitis
2.Gastrointestinal bleeding Hematemesis – commonest presentation Anorectal bleeding – found in 44% patient.
3.Patient history – Hepatitis B, Hepatitis C, blood transfusion, Umbilical catheterization.
EXAMINATION
1.Abdominal wall veins Caput Medusae – Prominent collateral veins radiating from umbilicus & flow is away from umbilicus.
2.Splenomegaly – Single most important diagnostic sign of PH.
3.Hepatomegaly - Soft liver – extrahepatic portal venous obstruction Firm liver – cirrhosis
4.Ascitis – Ascitis in PH always indicates liver cell failure in addition to PH. Ascitis is rarely due to PH done.
5.Rectal examination – Anorectal varices
6.Features of causative disease - eg. Cirrhosis – stigmata of cirrhosis
INVESTIGATION
1.Ba-swallow : Filling defect in the regular contour of the esophagus. They are most often in the lower third of the esophagus. Gastric varices pass through the cardia, line The fundus in a wormlike fashion.
2.Doppler ultrasound : Demonstrate the anatomy of PV & hepatic artery, presence of esophageal varices, portal systemic shunt patency & portal blood flow. A large PV with collateral confirm PH. Doppler US as accurately as by angiography providing optimal technical expertise.
3. Endoscopy : It always direct visualization of esophageal varices & confirming the PH. The size of varices must graded. (Cones grading)
i.Grade – 1 =Varices can be depressed by the endoscope
ii.Grade – 2= Varices can not be depressed.
iii.Grade – 3 = Varices are confluent around the circumference of the esophagus.
4.MRI & CT (With IV contrast) : are very sensitive methods for detection of collateral circulation of PH. They give better definition of PV. Those have largely been replaced by endoscopy.
5.Portal venography : With the advent of modern technology this is rarely done now a days.
6.Etiologic investigations for viral hepatitis (HBV, HEV, HDV), Wilson disease, galactosaemia, TORCH infection.
TREATMENT
•The therapy of PH is two fold :
A.Emergency treatment of potentially life threatening hemorrhage.
B.Prevention of bleeding.
A.Management of acute variceal bleeding :
1)Patient with variceal bleeding must focus on fluid restriction - Initially crystalloid fluid followed by transfusion of RBC.
2)Correction of coagulopathy : Administration of Vit-K or the infusion of Platelets or fresh frozen plasma or both may be required.
3)A NG tube should be placed to document the presence of blood within the stomach & to monitor the ongoing bleeding.
4)An H2-blocker should be given IV to reduce the risk of bleeding from gastric erosion. In most patients, particularly those with extrahepatic PH & with normal hepatic synthetic function bleeding usually stops spontaneously.
5)Pharmacological therapy :
a)Vasopressin, one of its analog is commonly used. It increases splanchnic vascular tone & thus decreasing portal blood flow. 0.33 U/kg over 20 minutes followed by continued infusion of 0.2 U/1.73 m²/min. side effects – vasoconstriction, which can impair cardiac function & perfusion to the heart, bowel & kidneys & may also exacerbate fluid retention.
b)Nitroglycerine with vasopressin
c)Somatostatin
6)If bleeding can not be controlled –
a)Endoscopic sclerosis or
b)Elastic bond ligation of esophageal varices are important options.
7) If bleeding continues despite pharmacologic & endoscopic measures -
a)Introduce a Sengstaken-Blackmore tube
b)Portocaval shunt
c)Orthotopic liver transplantation – in intrahepatic disease
d)TIPS (Transjugular intrahepatic portosystemic shunt) – A shunt is placed by an interventional radiologist between right hepatic vein & the rt. Or lt.branch of the PV.
8)Bacterial infection is associated with failure of control of bleeding. Prophylaxis with antibiotic eg. Ciprofloxacin significantly increases the patients long term survival.
9)Hepatic encephalopathy is prevented by
- Lactulose
- Phosphate enema
- Neomycin (can cause nephrotoxicity)
10) If ascitis is tense – Paracentesis may be done with caution & spironolactone may be used.
11)Sedatives should be avoided by oxazepum may be used when necessary.
B.Prevention of bleeding & prophylaxis against bleeding :
1)Improvement of liver function by removing the inflicting causative agent or by treatment.
2)Aspirin & NSAID should be avoided.
3)No protection comes from avoiding certain folds such as spices or from taking ling-term H2-blocker.
4)Propanolol (a beta blocker) :
Reduces portal pressure by splanchnic – vasoconstriction & to a lesser extent, by reducing CO. Hepatic arterial flow is reduced. A therapeutic effect s thought to result when the pulse rate is reduced by at least 25% or blood pressure by 15 mm Hg.
5) Nitrates : Isosorbide (Reduce portal pressure).
6) Endoscopic sclerotherapy
7) Endoscopic venoligation.
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