Use of Rivaroxaban for Prophylaxis of Superficial Venous Thrombosis in Klippel-Trenaunay- Weber Syndrome - Case Report and Systematic Review
Authors: Qamar Hina , Wu Cynthia 
Published: October 2019

Abstract
INTRODUCTION:
We present a case of a young man with Klippel Trenaunay Weber Syndrome (KTWS) characterized by recurrent superficial vein thrombosis (SVT) complicated by an episode of disseminated intravascular coagulation (DIC) who ultimately was maintained on prophylactic rivaroxaban to prevent recurrent thrombotic events. We performed a literature search to identify similar cases and to summarize common presenting features and attempted treatment modalities.
CASE DESCRIPTION:
An 18 year old man with KTWS presented with a large vascular malformation over his left chest and arm developed acute worsening SVT post sodium tetradecyl injection. Further investigation revealed a severe DIC was also present. On exam, the venous malformation and left arm were extremely tender with significant bruising. Presenting labs: Hg 24, platelet 98, bilirubin 588 (unconjugated 212), LDH 1597, PTT 32, INR 1.9, fibrinogen 1.1, Ddimer >20. He was treated with aggressive supportive care for DIC and routine deep vein thrombosis (DVT) prophylaxis with low-molecular-weight heparin (LMWH). Symptoms improved after anticoagulation was started. Ultrasound of his left arm revealed old SVT with recanulization within the venous malformation. He subsequently developed recurrent painful crises in his arm secondary to recurrent SVT. These were usually treated with short term LMWH. Imaging studies ruled out any deep vein thrombotic events. We eventually elected to commence indefinite duration anticoagulation with rivaroxaban 10mg daily with significant decrease in further acute flares.
METHODS:
To review how thrombotic manifestations of KTWS are managed, we performed a comprehensive literature search on PubMed using MESH terms: Klippel Trenaunay Weber Syndrome, Thrombosis, DIC and Kasabach-Merritt coagulopathy.
RESULTS:
We found 99 abstracts. 87 were excluded for non thrombotic complications of KTWS. 13 case reports focusing on treatment of thrombotic manifestations of KTWS were analyzed further. These included 12 case reports reviewing management of DVT in KTWS and 1 case report reviewing management of SVT in KTWS however with no DIC. 3 of these abstracts also reviewed management of coagulopathy (DIC or local intravascular coagulopathy). Of the 12 case reports, 5 described patients with deep vein thrombosis in KTWS treated with therapeutic warfarin; 4 patients improved however 1 died of cor pulmonale. An additional 5 cases of DVT in KTWS were successfully managed with therapeutic LMWH. 2 of these cases were also complicated by DIC. One case report described use of therapeutic rivaroxaban (20mg daily) to manage DVT in KTWS. This case was also complicated by DIC. There were no case reports describing the prevention of SVT in KTWS.
CONCLUSION: To our knowledge this is the first case report to describe successful off-label use of prophylactic rivaroxaban to prevent further thrombotic events in a patient with KTWS.

Disclosures
Off Label Use: RIVAROXABAN -- PROPHYLACTIC ANTI-THROMBOSIS FOR SUPERFICIAL VEIN THROMBOSIS. Wu:Leo Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.