Portal Vein Thrombosis as a Complication of COVID-19 Infection – A Case Study

COVID-19 and Thrombosis

SARS-CoV-2 infection is accompanied by an increased risk of a hypercoagulable state, and according to data from the available literature, up to 30% of critically ill patients develop deep vein thrombosis (DVT) or pulmonary embolism (PE). Arterial thromboembolism is considerably less common. Splanchnic vein thrombosis is relatively rare, but it has also been reported in patients with mild COVID-19 who presented primarily with respiratory symptoms. In portal vein thrombosis (PVT), there is a risk of rapid clot progression, which can extend to the mesenteric veins and cause intestinal ischemia. Authors from the gastroenterology/hepatology department of the State University of New York hospital in Brooklyn published a unique case in the World Journal of Clinical Cases of a patient with simultaneous portal vein thrombosis (PVT) and splenic artery thrombosis.

Case Description

The patient, a 77-year-old man with no prior liver disease, presented to the emergency department with a three-day history of left-sided abdominal pain. A week earlier, he had been diagnosed with COVID-19 with mild symptoms, treated with nirmatrelvir/ritonavir. On physical examination, mild tenderness was noted in the right and left lower quadrants of the abdomen, without other abnormalities. Laboratory tests revealed leukocytosis (12.5 × 10^9/l), hyperbilirubinemia (27.36 μmol/l), and elevated ALT levels (1.04 μkat/l). A computed tomography (CT) scan of the abdomen and pelvis revealed acute PVT, with a thrombus extending from the distal portion of the portal vein into both the left and right branches. Another thrombus was found in the distal part of the splenic artery, and a developing splenic infarction was detected. An abnormal soft tissue mass of approximately 2.5 cm was seen at the splenic hilum, likely reflecting inflammatory changes, although an exophytic pancreatic lesion could not be ruled out. As part of the diagnostic work-up, additional tests for hypercoagulable disorders (prothrombin gene mutation, factor V Leiden mutation, antiphospholipid antibodies, JAK2 mutation) were performed, all with negative results. Anticoagulant therapy with full-dose enoxaparin was immediately initiated. After three days, the patient reported complete resolution of his abdominal pain and was discharged for home care with six months of oral anticoagulation treatment with apixaban. Follow-up magnetic resonance imaging (MRI) eight weeks after discharge showed reperfusion of the portal vein. The previously observed poorly defined mass in the splenic hilum was no longer present, ruling out a pancreatic lesion.

Discussion and Conclusion

Although the risk of thrombotic complications generally correlates with the severity of COVID-19, thrombosis has also been reported in patients with mild or asymptomatic cases of the disease, and the risk persists even after respiratory and other symptoms have resolved. The mortality rate associated with PVT in COVID-19 patients can reach up to 16%, making early diagnosis and treatment crucial. Clinical symptoms typically include abdominal pain but are otherwise nonspecific. Therefore, imaging techniques are essential for diagnosis. Prompt initiation of anticoagulant therapy is key, with low molecular weight heparins (LMWH) usually the first-line treatment. LMWH is preferred over direct oral anticoagulants (DOACs) due to the low likelihood of interactions between LMWH and concomitant medications, particularly antiviral agents. Although a relatively rare complication, splanchnic vein thrombosis should be considered in the differential diagnosis of patients with abdominal pain during the course of COVID-19.

(Source: Abramowitz B. R., Coles M., Aytaman A. et al. Simultaneous portal vein thrombosis and splenic vein thrombosis in a COVID-19 patient: a case report and review of literature. World J Clin Cases 2024 Jun 26; 12 (18): 3561−3566, doi: 10.12998/wjcc.v12.i18.3561.)