Portomesenteric Venous Thrombosis As First Presentation of Thrombophilic Disorders in Adolescents
Authors: Boiko Julie R. , Cooper James D. 
Published: October 2019

Abstract
Introduction
Portomesenteric venous thrombosis is rare in children and adolescents. Rapid recognition of this uncommon phenomenon is essential to prevent resultant bowel ischemia and necrosis. Prior studies have shown that most cases are associated with central venous lines, abdominal trauma, autoimmunity, malignancy, or inflammatory bowel disease. Here we present a series of four adolescent patients with no significant past medical history or previously identified thrombophilia who presented with subacute abdominal pain and were ultimately found to have portomesenteric venous thrombosis.
Methods
We conducted a retrospective analysis of adolescent patients diagnosed with portomesenteric venous thrombosis at our center between July 2012 and July 2014. We evaluated baseline demographics, diagnostic workup, radiologic findings, therapy, and clot resolution.
Results
We identified four patients (3 female, 1 male) with a median age of 15 years (range 14-17). No patients had history of clots, known thrombophilias, or predisposing conditions. All patients had presented to the general pediatric inpatient service with the chief complaint of acute to subacute abdominal pain originating 2-4 weeks prior and accompanied by diarrhea and/or constipation, anorexia, and nausea/emesis. After extensive preliminary diagnostic investigations, three patients’ clots were eventually discovered on computed tomography, and one patient’s clot was found on ultrasound. The thrombosis sites among the four patients were superior mesenteric (n=4), portal (n=3), splenic (n=2), inferior mesenteric (n=1), hepatic (n=1), inferior vena cava (n=1), and renal (n=1) veins. Two patients' clots were completely occlusive; however, no patients had bowel necrosis requiring surgical intervention.
All patients were treated with standard anticoagulation while inpatient. One patient additionally underwent direct tPA thrombolysis and thrombectomy and required repeat direct thrombolysis and continuous tPA infusion due to clot extension. All patients were discharged on therapeutic anticoagulation with at least partial resolution of their clots. Median followup was 7 months (4-9 months). One patient later developed an upper extremity deep vein thrombosis associated with a peripheral line inserted for heparin delivery; no other patients developed clots at new sites or experienced extension of their original clots. All workups remained negative for inflammatory bowel disease, malignancies, and rheumatologic conditions.
All patients were evaluated for underlying thrombophilic conditions, each undergoing a variable set of laboratory tests during hospitalization and followup. One patient had a durable protein C deficiency. Another patient was heterozygous for the factor V Leiden mutation and had a transient lupus anticoagulant during and until four months after hospitalization. A third patient who smoked had no detectable thrombophilia during hospitalization but experienced elevated fibrinogen and anti-β2-glycoprotein I antibodies four months after initial presentation. A fourth patient who smoked as well as had initiated an estrogen patch within the past month had a positive hexagonal lipid neutralization during early hospitalization.
Conclusion
We demonstrate that portomesenteric venous thrombosis can be the first presentation of a thrombophilic disorder in previously healthy adolescents. As it is a rare diagnosis with significant long-term complication potential, future work should standardize diagnostic approaches to adolescent subacute abdominal pain to enable rapid thrombosis recognition and prompt anticoagulation initiation. Furthermore, given the prevalence of thrombophilias identified in our patients despite variable laboratory testing regimens, it is imperative to develop a systematic approach for comprehensive thrombophilic testing in adolescents diagnosed with portomesenteric venous thrombosis.

Disclosures
No relevant conflicts of interest to declare.