Intra-Abdominal Venous Thrombosis: Characteristics of Pediatric and Adult Patients
Authors: Landi Daniel , Beckman Michele , Shah Nirmish , Bockenstedt Paula , Heit John A. , Kulkarni Roshni , Manco-Johnson Marilyn , Moll Stephan , Philipp Claire S. , Andersen Judith C. , Ortel Thomas L. 
Published: October 2019

Abstract
Abstract 4219

Background:
Clinical characteristics associated with abdominal vein thrombosis (including hepatic, portal, and mesenteric veins; renal veins; and inferior vena cava [IVC]) overlap with characteristics associated with deep vein thrombosis (DVT) in the legs and pulmonary embolism (PE) but also possess unique attributes. These characteristics may differ between adult and pediatric patient groups.

Methods:
Using a standardized data-collection form, demographic and baseline characteristics were prospectively collected from consecutive consenting patients enrolled within one of seven Thrombosis and Hemostasis Centers over a seven-year period, August 2003 to June 2010. Patients with intra-abdominal venous thrombosis (defined as abdominal and renal veins, and IVC) were divided into pediatric (age <18 years) and adult (age ≥18 years) groups and compared to patients in the same age ranges with lower extremity DVT and/or PE. RESULTS: As of June 2010, the Patient Registry contained a total of 3105 patients with venous thromboembolism (VTE). A total of 270 patients had intra-abdominal thrombosis (9%) compared to 2276 with lower extremity DVT and/or PE (73%). Of the intra-abdominal clots, pediatric patients were more likely to have IVC thrombus (22 of 42; 52%) than adults (38 of 228; 17%; p<0.0001); conversely, pediatric patients were less likely to have hepatic, portal, and mesenteric thrombosis (n=25; 60%) than adults (n=195; 86%, p<.0001). For adult patients, proportionately more women had abdominal thrombosis (157 of 228; 68.9%) than DVT/PE (1306 of 2140; 61%; p=0.02); in contrast, comparable numbers of female pediatric patients had abdominal thrombosis (20 of 42; 47.6%) and DVT/PE (68 of 136; 50%). The mean age for patients having abdominal thrombosis was lower than patients having DVT/PE for both adults (38.3 vs 43.0 yrs; p<0.0001) and pediatric patients (9.0 vs 11.9 yrs; p=0.014). Similarly, the mean body mass index was lower for patients having abdominal thrombosis than patients having DVT/PE for both adults (28.1 vs 30.8; p<0.0001) and pediatric patients (21.5 vs. 24.7; p=0.05). There were no relationships with race, ethnicity, or inherited thrombophilic disorders. In adults, autoimmune conditions (21.9 vs 13.6; p=0.0007) and recent surgery (14.0 vs 9.2; p=0.02) were more common in patients with abdominal thrombosis, whereas, hyperlipidemia was more frequent in patients with DVT/PE (8.3 vs 13.2; p=0.04). None of these relationships were seen in the pediatric patients, but trauma was more frequently seen in pediatric patients with DVT/PE than abdominal thrombosis. Sixty-one adult (26.8%) and 6 pediatric patients (14.3%) had another VTE elsewhere, with most occurring after the initial event (21 DVT and 7 PE). Similar proportions of adult and pediatric patients had arterial thromboembolic events for both abdominal thrombosis and DVT/PE. CONCLUSIONS: Adult patients with abdominal thrombosis are more likely female, have hepatic, portal and/or mesenteric vein thrombosis, and common co-morbid conditions include recent surgery and autoimmune disorders. Pediatric patients are evenly divided between male and female, more commonly have IVC thrombosis, and co-morbid conditions include recent trauma. Both adult and pediatric patients with abdominal thrombosis tend to be younger and have a lower BMI than patients with DVT and/or PE. We also found a high rate of concurrent thrombosis in both adult and pediatric patients with abdominal thrombosis. In summary, patients with abdominal thrombosis display different clinical characteristics when compared to those with DVT/PE, specifically in terms of gender, location of thrombosis, and associated co-morbidities. Some of these differences, such as higher rates of IVC thrombosis in pediatric patients with abdominal thrombosis, might be caused by variance between genetic and anatomic factors. Further studies are warranted to explain these differences.

Disclosures:
Kulkarni: Novo Nordisk: Membership on an entity's Board of Directors or advisory committees, Participate in clinical trials. Philipp:Baxter: Research Funding; Wyeth: Research Funding; Octapharma: Research Funding. Ortel:Sanofi-Aventis: Consultancy, Research Funding; Ortho-McNeil: Consultancy; GlaxoSmithKline: Research Funding; Eisai: Research Funding; Pfizer: Research Funding.