PORTAL VEIN THROMBOSIS
Epidemiology: Rare (0.05-0.5% in autopsy studies), but leading cause of portal HTN in non-cirrhotics in West. Often assx until variceal bleeding occurs. WIDE variety of etiologies.
Etiologies: Virchow’s Triad
1. Cirrhosis (24-32%): decreased portal flow, periportal lymphangitis
2. Neoplasm (21-24%): direct invasion, extrinsic compression
a. most common: pancreatic (11-12%), primary hepatocellular (5-6% in Western, much higher elsewhere)
b. others associated: lung, stomach, prostate, uterus, kidney, cholangioca, carcinoid, primary liver lymphoma
1. Infection (10-25%- most common cause in children): portal pyemia- often secondary to apendicitis, biliary tract infections, sepsis, amoebic colitis, diverticulitis
2. Inflammatory: pancreatitis (3-5%), appendicitis, cholecystitis, EtOH hepatitis, perforated DU.
3. Myeloproliferative disorders (3-12%): may be responsible for many “idiopathic” cases.
4. Hypercoagulable states
a. inherited: ProC, ProS, AT III
b. acquired: nephrotic syndrome, DIC, IBD, malignancy, estrogen use.
1. Other: non-cirrhotic portal fibrosis, trauma, post-surgical (esp. post-splenectomy).
Clinical features: Hematemesis/melena from ruptured varices is most common presentation.
1. SXS/SNS: increased abd girth, pain, N/V, anorexia, weight loss, diarrhea
2. EXAM: splenomegaly (75-100%), mild hepatomegaly, abd tenderness. Ascites less common, mild, transient.
LABS: may be mild elevations of transaminases, alk phos, bilis.
*may be differentiated from Budd-Chiari by hepatomegaly,
ascites, hepatocellular dysfunction seen in Budd-Chiari..
Imaging: Start with ultrasound, MR if available
1. Venogram: gold standard.
2. US: highly sensitive (>90%), but operator dependent.
3. CT: less sensitive (75%), highly specific.
4. MR: highly sensitive and specific.
1. Variceal hemorrhage: average 5 episodes/pt.
2. Hepatic encephalopathy: uncommon unless coexisting cirrhosis or shunt surgery.
3. Small bowel infarction: extension of thrombus to SMV
a. Control acute bleeding: correct coagulopathy, transfuse, SB balloon, vasopressin, endoscopic sclerotherapy, surgery.
b. Catheter directed thrombolysis: some anecdotal successes.
a. Treat underlying etiology.
b. Prophylactic sclerotherapy/banding of varices.
c. Surgical shunt: usually spenorenal, very effective for non-cirrhotics.
d. Anticoagulation: no clear benefit unless underlying hypercoagulable state.
Cohen, et al. Am J Med. Feb 1992, 92: 73-182.