P110 | Use of DOACs in the treatment of deep vein thrombosis secondary to inferior vena cava agenesis: A case study from the Provincial Health Services Company of Trento

N. Osti¹, V. Racanelli², A. Maino³ | ¹UO di Medicina Interna, Ospedale Valli del Noce, Azienda Provinciale per i Servizi Sanitari di Trento, ²CISMed, Università degli Studi di Trento, ³UO di Medicina Interna, Ospedale Santa Chiara, Azienda Provinciale per i Servizi Sanitari di Trento, Italy

Background: Inferior vena cava agenesis (IVCA) is a rare congenital anomaly (estimated prevalence 0.0005-1%), and represents an underestimated cause of deep vein thrombosis (DVT), particularly in young individuals. Data on the efficacy and safety of using DOACs in this particular clinical context are scarce.
Description of the case series: We report three consecutive cases of DVT in AVCI (mean age 32 years) treated with DOACs, referred to our service since 2016. Case 1, a 23-year-old male, presented in 2023 with a thrombosis of the venous collaterals of the right renal vein, which began with ipsilateral hydronephrosis. I was placed on rivaroxaban 20 mg daily, which is still ongoing. Case 2, a 34-year-old woman, developed extensive bilateral iliofemoral-popliteal venous thrombosis with caval involvement in 2008. Since 2016, he has been on prophylactic therapy with apixaban 2.5 mg twice daily (8 years). Case 3 is a 42-year-old man with a first right iliofemoral DVT in 1999, which recurred after warfarin was discontinued in 2010. Since 2019, he has been on rivaroxaban therapy (20 mg daily until 2021, then 10 mg daily). After a mean follow-up of 4.6 years, there have been no thromboembolic recurrences or bleeding complications to date.
Conclusions: AVCI is a rare condition, but it should always be considered as a cause of DVT in young individuals. The results of our experience seem to support the use of DOACs in the treatment of DVT secondary to AVCI, both in terms of efficacy and safety.