Portal Vein Thrombosis

50 year old with cirrhosis and ascites. Diagnosis? • Xray of the Week

Figure 1. What are the important findings?

Figure 2.

A: Contrast enhanced coronal CT scan showing thrombus in the portal vein (yellow arrow) as well as a cirrhotic liver with nodular surface (red arrow) surrounded by ascites (green arrow).

B and C: Contrast enhanced axial CT images showing ascites (green arrows) as well as confirmation of the occlusion of the hepatic portal vein (yellow arrows).

Figure 3.

A: Color doppler ultrasound of portal vein thrombosis in a different patient. Note the echogenic thrombus in the dilated portal vein (PV). Color doppler shows no flow in the portal vein. https://www.slideshare.net/shaffar75/doppler-ultrasound-of-portal-vein-thrombosis

Discussion:

Portal vein thrombosis (PVT) (Figs. 1,2) is a common complication in patients with liver cirrhosis and is also associated with malignancies and inherited thrombophilia disorders [1]. The pathophysiology of hepatic PVT can be explained by the well-known Virchow’s triad, which explains the causes of thrombosis including stasis, endothelial injury and hypercoagulability. Hepatic PVT in liver cirrhosis patients typically is the result of portal hypertension and stagnation of blood in the portal system leading to partial or complete thrombosis of the portal vein [2]. Up to 43% of patients may be asymptomatic; however, many present with abdominal pain due to bowel ischemia and/or gastrointestinal bleeding due to varices [3]. Due to the high proportion of asymptomatic patients, PVT is often a missed diagnosis or an incidental finding, and when it becomes symptomatic can lead to deadly consequences. Therefore, it is important to diagnose PVT with imaging as early as possible.

PVT is usually evaluated first by ultrasound which has a sensitivity and specificity greater than 80%. Ultrasound evaluation of PVT typically shows hyperechoic material in the portal vein and diminished flow with doppler (Fig. 3). Contrast CT and MRI can also be used in the evaluation of PVT and can provide additional information such as bowel ischemia, portal hypertension, portal hypertension, including ascites, splenomegaly, and portosystemic shunts [4-6]. On CT scan, PVT is depicted as a non-enhancing filling defect (Figs. 1, 2). Similar to CT, MR demonstrates abnormal signal within the lumen of the portal vein; however, signal intensity depends on the age of the clot [5,6]. Linear regions of calcification within the clot indicate chronic thrombosis [6].

Treatment of PVT depends on the cause of the PVT. Options for treatment of PVT can include observation, anticoagulation, shunt placement, and thrombectomy. Treatment of PVT in patients with liver cirrhosis is controversial due to lack of clinical trials. Some studies support the use of anticoagulants while others support the use of transjugular intrahepatic portosystemic shunts (TIPS). These both have risks including bleeding with anticoagulants and hepatic encephalopathy with TIPS [7]. When treating PVT in a liver cirrhosis patient, it is also important to evaluate for other life-threatening consequences including esophageal varices with endoscopy [4].

References:

1. Nery F, Chevret S, Condat B, et al. Causes and consequences of portal vein thrombosis in 1,243 patients with cirrhosis: results of a longitudinal study. Hepatology. 2015;61(2):660-667. doi:10.1002/hep.27546

2. Intagliata NM, Caldwell SH, Tripodi A. Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis. Gastroenterology. 2019;156(6):1582-1599.e1. doi:10.1053/j.gastro.2019.01.265

3. Amitrano L, Guardascione MA, Brancaccio V, et al. Risk factors and clinical presentation of portal vein thrombosis in patients with liver cirrhosis. J Hepatol. 2004;40(5):736-741. doi:10.1016/j.jhep.2004.01.001

4. Chawla YK, Bodh V. Portal vein thrombosis. J Clin Exp Hepatol. 2015;5(1):22-40. doi:10.1016/j.jceh.2014.12.008

5. Parvey HR, Raval B, Sandler CM. Portal vein thrombosis: imaging findings. AJR Am J Roentgenol. 1994;162(1):77-81. doi:10.2214/ajr.162.1.8273695

6. Jha RC, Khera SS, Kalaria AD. Portal Vein Thrombosis: Imaging the Spectrum of Disease With an Emphasis on MRI Features. AJR Am J Roentgenol. 2018 Jul;211(1):14-24. doi:10.2214/AJR.18.19548

7. Sharma AM, Zhu D, Henry Z. Portal vein thrombosis: When to treat and how?. Vasc Med. 2016;21(1):61-69. doi:10.1177/1358863X15611224

Sai Kilaru is a medical student at Central Michigan University College of Medicine and plans to pursue a residency in diagnostic radiology. Sai first realized his interest in radiology while he was conducting research in radiomics at the University of Michigan, where he graduated from in 2018 with a Bachelor of Science degree in Neuroscience. As he progressed through his third year of medical school, Sai realized the very important role that radiology has in medicine and decided to take on the challenge of diagnosing patients in the future. Sai is also a member of the Gold Humanism Honor Society and is involved with giving back to the community at a local free clinic as a medical assistant. In his spare time, Sai enjoys playing basketball, board games, spending time with friends, and exploring new restaurants.

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Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.

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