The Triple Challenge of Managing Anticoagulant Therapy in a Patient with Concurrent Colorectal Cancer, Thromboembolism, and Renal Failure: A Case Report

Introduction: The management of anticoagulation in patients with gastrointestinal cancer is complicated by the elevated risk of bleeding, which is amplified by concomitant renal failure affecting the pharmacokinetics of anticoagulant drugs. This case report illustrates the complexities of selecting a safe and effective anticoagulant regimen in this high-risk scenario. Case Presentation: A 77-year-old male patient with a history of colorectal cancer and chronic kidney disease (creatinine level 2.3 mg/dL) presented with acute dyspnea. Doppler ultrasound confirmed deep vein thrombosis in the left femoral vein. Due to renal impairment, computed tomography pulmonary angiography was contraindicated; a ventilation-perfusion (V/Q) lung scan was performed instead, which diagnosed pulmonary embolism. The primary dilemma was selecting an appropriate anticoagulant that could balance the high risk of recurrent thromboembolism against the heightened risks of drug accumulation and catastrophic gastrointestinal bleeding. The selection of the therapeutic regimen required a multidisciplinary evaluation involving cardiology, nephrology, and clinical pharmacy experts. To mitigate the risk of drug accumulation while ensuring efficacy, subcutaneous enoxaparin was initiated at a renal-adjusted dose of 60 mg subcutaneously once daily. This approach aimed to provide effective treatment for cancer-associated thrombosis while carefully monitoring the patient’s clinical status in the setting of severe renal impairment. The patient was discharged on this regimen and completed a full 6-month course of enoxaparin without any thromboembolic or bleeding complications. At the 9-month follow-up, the patient remains asymptomatic and off anticoagulants. Based on recent colonoscopy findings showing no active disease or residual mass, the patient requires no further surgical intervention or anticoagulant therapy, demonstrating an excellent clinical outcome. Conclusion: This case underscores the need for a tailored, multidisciplinary approach to anticoagulation in patients with gastrointestinal cancer, thromboembolic disease, and renal insufficiency. Low-molecular-weight heparin (LMWH), alongside careful dose adjustment and continuous monitoring, represents a viable therapeutic option in this complex patient population.