Portal Vein Obstruction Workup
- Author: Adnan Said, MD, MSPH; Chief Editor: BS Anand, MD more...
Liver function test results are only mildly elevated in the absence of underlying cirrhosis or massive hepatic malignancy.
Inherited coagulation disorders, such as activated protein C resistance, are listed in the image below. Tests for these disorders should be ordered in any case of portal vein thrombosis in which the diagnosis is unclear.
In the presence of underlying hepatic insufficiency, levels may be low, presumably secondary to decreased production in the liver. Caution is therefore needed in making the diagnosis of an inherited thrombophilic disorder in this scenario.
Some authors suggest checking for an inherited coagulation disorder even when a local factor for portal vein thrombosis is obvious and, conversely, also checking for local factors even in the presence of inherited coagulation disorders because more than one risk factor may be present in a single patient.
Ultrasonography is the first-line diagnostic modality because of its accuracy, affordability, and noninvasiveness. Note the following:
The thrombus is observed as an echogenic lesion within the portal vein, though a recently formed thrombus may be anechoic (ie, not observable on standard grey-scale ultrasound).
The addition of color Doppler imaging is especially helpful in the detection of portal vein flow and the diagnosis of portal vein obstruction.
The sensitivity is around 70-90%, with a specificity of 99%. With Doppler, the false-positive rate is 9% in patients with cirrhosis because of sluggish or turbulent portal vein flow.
Major limitations are obesity and nonvisualization secondary to bowel gas. 
The presence of pulsatile, arterial flow in the thrombus correlates with a malignant, not bland, thrombus.
Endoscopic ultrasonography (EUS)
Although not a common diagnostic modality, EUS has recently been found to be 81% sensitive and 93% specific in patients with portal vein thrombosis as compared to patients with thrombus confirmed by contrast-enhanced CT scan or surgery.
MRI and magnetic resonance angiography (MRA)
MRI/MRA is the next step if further portal venous information is needed. MRI is helpful if hepatic parenchymal detail is required (in hepatic malignancies), and, unlike CT scan, MRI can also quantitate portal and hepatic vessel flow, which is required in the planning of interventions, such as shunt surgery, transjugular intrahepatic portosystemic shunt (TIPS), or liver transplantation. Note the following:
Acute clot (<5 wk) appears hyperintense on both T1- and T2-weighted images, whereas older clots appear hyperintense only on T2-weighted images. Tumor thrombi can be differentiated from bland thrombi because they appear more hyperintense on T2-weighted images and enhance with gadolinium.
The overall sensitivity, specificity, and accuracy of the MRA are 100%, 98%, and 99%, respectively. There is a high sensitivity for the detection of submucosal, serosal, paraesophageal collaterals.
Contrast-enhanced CT scanning shows a thrombus as a nonenhanced intraluminal-filling defect. (See the images below.) This imaging modality has the advantage over ultrasonography in displaying varices (sensitivity, 65-85%) and parenchymal hepatic abnormalities.
The combination of CT scan and Doppler ultrasonography is common in the evaluation of portal vein obstruction.
Angiography is not usually required to confirm the diagnosis of portal vein thrombosis in the presence of CT scan or MRI. Angiography's major value lies in preoperative planning before shunt surgery or liver transplantation; however, it is not a prerequisite, and many transplant centers use MRI/MRA for this purpose.
Even angiography can provide false-positive results in portal hypertension in the presence of extensive portosystemic collaterals in which the mesenteric flow is directed away from a patent portal vein.
Usually, no specific alterations are observed at the histologic examination. In rats, apoptosis has been described in the underperfused portion, with increased mitotic activity in the remaining well-perfused liver.
Chawla Y, Dhiman RK. Intrahepatic portal venopathy and related disorders of the liver. Semin Liver Dis. 2008 Aug. 28(3):270-81. [Medline].
Abd El-Hamid N, Taylor RM, Marinello D, Mufti GJ, Patel R, Mieli-Vergani G, et al. Aetiology and management of extrahepatic portal vein obstruction in children: King's College Hospital experience. J Pediatr Gastroenterol Nutr. 2008 Nov. 47(5):630-4. [Medline].
Sharma P, Sharma BC, Puri V, Sarin SK. Natural history of minimal hepatic encephalopathy in patients with extrahepatic portal vein obstruction. Am J Gastroenterol. 2009 Apr. 104(4):885-90. [Medline].
Facciuto ME, Rodriguez-Davalos MI, Singh MK, Rocca JP, Rochon C, Chen W, et al. Recanalized umbilical vein conduit for meso-Rex bypass in extrahepatic portal vein obstruction. Surgery. 2009 Apr. 145(4):406-10. [Medline].
Nihal L, Bapat MR, Rathi P, Shah NS, Karvat A, Abraham P, et al. Relation of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 levels to growth retardation in extrahepatic portal vein obstruction. Hepatol Int. 2009 Mar. 3(1):305-9. [Medline]. [Full Text].
Nakao A, Kanzaki A, Fujii T, Kodera Y, Yamada S, Sugimoto H, et al. Correlation Between Radiographic Classification and Pathological Grade of Portal Vein Wall Invasion in Pancreatic Head Cancer. Ann Surg. 2011 Dec 8. [Medline].
Liu Q, Chen J, Li H, Liang B, Zhang L, Hu T. Hepatocellular carcinoma with bile duct tumor thrombi: Correlation of magnetic resonance imaging features to histopathologic manifestations. Eur J Radiol. 2009 Jun 5. [Medline].
Tritou I, Megremis S, Stefanaki E, Goumenakis M, Sfakianaki E. Sonographic detection of transient gas in the portal vein in an infant following abdominal surgery: A possible sign of adhesive small bowel obstruction. J Clin Ultrasound. 2011 Sep 26. [Medline].
Alberti D, Colusso M, Cheli M, Ravelli P, Indriolo A, Signorelli S, et al. Results of a stepwise approach to extrahepatic portal vein obstruction in children. J Pediatr Gastroenterol Nutr. 2013 Nov. 57(5):619-26. [Medline].
Guérin F, Porras J, Fabre M, Guettier C, Pariente D, Bernard O, et al. Liver nodules after portal systemic shunt surgery for extrahepatic portal vein obstruction in children. J Pediatr Surg. 2009 Jul. 44(7):1337-43. [Medline].
Arora A, Sarin SK. Multimodality imaging of primary extrahepatic portal vein obstruction (EHPVO): what every radiologist should know. Br J Radiol. 2015 Aug. 88 (1052):20150008. [Medline].
Kumar A, Sharma P, Arora A. Review article: portal vein obstruction--epidemiology, pathogenesis, natural history, prognosis and treatment. Aliment Pharmacol Ther. 2015 Feb. 41 (3):276-92. [Medline].
Wu XP, Ni JM, Zhang ZY, et al. Preoperative evaluation of malignant perihilar biliary obstruction: negative-contrast CT cholangiopancreatography and CT angiography versus MRCP and MR angiography. AJR Am J Roentgenol. 2015 Oct. 205 (4):780-8. [Medline].
Ha TY, Kim KM, Ko GY, et al. Variant meso-Rex bypass with transposition of abdominal autogenous vein for the management of idiopathic extrahepatic portal vein obstruction: a retrospective observational study. BMC Surg. 2015 Oct 17. 15:116. [Medline].
Arrive L, Hodoul M, Arbache A, Slavikova-Boucher L, Menu Y, El Mouhadi S. Magnetic resonance cholangiography: Current and future perspectives. Clin Res Hepatol Gastroenterol. 2015 Dec. 39 (6):659-64. [Medline].
Yoshimatsu R, Yamagami T, Ishikawa M, et al. Embolization therapy for bleeding from jejunal loop varices due to extrahepatic portal vein obstruction. Minim Invasive Ther Allied Technol. 2016 Feb. 25 (1):57-61. [Medline].
Sekimoto T, Maruyama H, Kobayashi K, et al. Well-tolerated portal hypertension and favorable prognosis in adult patients with extrahepatic portal vein obstruction in Japan. Hepatol Res. 2015 Aug 29. [Medline].