Pocket Medicine

GASTROENTEROLOGY

HEPATIC VASCULAR DISEASE

Portal vein thrombosis (PVT) (Al Phar Ther 2009;30:881; J Hepatol 2012;56:S1)

•  Definition: thrombosis, constriction or invasion of portal vein → portal HTN → varices. Isolated splenic vein thrombosis (eg, 2° to pancreatitis) → isolated gastric varices.

•  Etiologies: cirrhosis, neoplasm (pancreas, HCC), abdominal infxn → pylephlebitis (infected thrombosis of PVT), hypercoag state (incl MPS), pancreatitis, IBD, surgery, trauma

•  Clinical manifestations

acute PVT: can p/w pain; often asx and dx as incidental finding on U/S or CT if mesenteric vein involved may p/w intestinal infarct; if fever consider pylephlebitis

chronic PVT: asx/incidental finding; may p/w s/s of portal HTN → hematemesis 2° variceal bleeding, splenomegaly, mild enceph; ascites uncommon unless cirrhosis

•  Diagnostic studies: LFTs usually normal; U/S w/ Doppler, MRA, CT (I+), angiography;

“portal cavernoma” network of hepatopedal collaterals in chronic PVT—can rarely cause biliary obstruction and cholestatic LFTs = portal cholangiopathy (may require surgery)

•  Treatment: eval for underlying cause (cirrhosis, MDS, hypercoag); if cirrhotic, Rx less clear

acute: LMWH → warfarin × 6 mo, or indefinitely if irreversible cause (except cirrhosis),

chronic: anticoag if noncirrhotic or hypercoag state; unclear if benefit > bleed risk

ppx: LMWH may prevent PVT & liver decomp in advanced cirrhosis (Gastro 2012;143:1253)

Varices: screen at dx; no evidence for 1° ppx of bleed; if bleed endoscopic Rx and bB. If refractory bleed consider TIPS, shunt. Isolated gastric varices 2° splenic vein thrombosis: splenectomy is curative.

Budd-Chiari syndrome (J Hepatol 2012;56:S1)

•  Occlusion of hepatic vein(s) or IVC → sinusoidal congestion and portal HTN

•  Etiol: ~50% due to myeloproliferative disorder a/w JAK2 mutations (esp. P. vera), other hypercoag state, tumor invasion (HCC, renal, adrenal), IVC webs, trauma, 1/4 idiopathic

•  Symptoms: hepatomegaly, RUQ pain, ascites, dilated venous collaterals

•  Dx: ± ↑ aminotransferases & AΦ; Doppler U/S of hepatic veins (85% Se & Sp); CT (I+) or MRI/MRV → vein occlusion or ↑ caudate lobe (separate venous drainage); “spider- web” pattern on hepatic venography; liver bx showing congestion (r/o right-sided CHF)

•  Treatment: anticoag (LMWH → warfarin); consider thrombolysis acutely; if short stenosis stent may be possible; consider TIPS (↑ occlusion risk c/w side-to-side portocaval shunt); liver transplant if hepatic failure or failed shunt (J Gastro Surg 2012;16:286)

Sinusoidal obstruction syndrome (SOS) (J Hepatol 2012;56:S1)

•  Occlusion of hepatic venules and sinusoids (formerly veno-occlusive disease)

•  Etiologies: HSCT, chemo (esp. cyclopho), XRT, Jamaican bush tea

•  Clinical manifestations: hepatomegaly, RUQ pain, ascites, weight gain, ↑ bilirubin

•  Dx: U/S w/ reversal of portal flow, but often not helpful; dx made clinically (↑ bili, wt gain/ascites and RUQ pain) or, if necessary, by liver bx or HVPG (>10 mmHg)

•  Treatment (20% mortality): supportive; ? defibrotide (adenosine agonist ↑ TPA levels)

•  Ppx: defibrotide; ursodeoxycholic acid for high-risk HSCT pop; ? use of low-dose heparin

Figure 3-8 Hepatic vasculature