S3040 Recurrent Deep Vein Thrombosis With the Use of Direct Oral Anticoagulation in a Patient With Previous Bariatric Surgery: A Case Report

INTRODUCTION: The most common bariatric surgery, sleeve gastrectomy (SG), reduces stomach volume, which leads to weight loss (Figure 1) 1 Bariatric surgery modifies the gastrointestinal tract anatomy and absorptive surface which may impede not only the absorption of nutrition, but also of medications Many commonly used direct oral anticoagulants (DOACs) are primarily absorbed in the proximal small intestine and stomach (Figure 2) There are no studies to date on the efficacy of DOACs following bariatric surgery 1 We present a case of a patient with prior SG who had recurrent deep vein thrombosis (DVT) while on apixaban CASE DESCRIPTION/METHODS: A 54-year-old male with a history of obesity, and prior SG presented to the hospital with one week of left lower extremity (LLE) pain Two weeks prior, he was diagnosed with DVT of the popliteal and peroneal veins and was started on apixaban He endorsed medication compliance and age-appropriate cancer screening He denied DVT provoking factors Physical exam was notable for LLE edema and tenderness Work up included negative d-dimer, COVID19 RNA, lupus anticoagulant, beta 2 glycoprotein, and cardiolipin LLE ultrasound showed new, occlusive thrombus in the distal superficial femoral vein CT chest, abdomen and pelvis were negative for pulmonary embolism and malignancy He was started on a heparin drip with a bridge to warfarin on discharge DISCUSSION: DOAC absorption may be affected by bariatric surgery Bariatric surgery alters both the GI tract anatomy, as well as drug metabolism and bioavailability due to alerted gastric pH, changes in body weight and adipose tissue composition 1 Unlike warfarin, which can be monitored for effective therapeutic levels with INR, DOACs are not monitored Thus, the efficacy and safety of DOACs in patients with bariatric surgery, poses a significant challenge 2 Literature regarding DOAC efficacy and safety in patients following bariatric surgery is limited Phase II and III trials of DOACs excluded patients who had undergone bariatric surgery Further studies of the safety and efficacy of DOACs in patients after bariatric surgery are needed as non-therapeutic levels of DOACs from impaired absorption may lead to serious complications