Nutcracker syndrome complicated by left renal vein thrombosis in a patient with protein S deficiency: a case report

초록

Aims/Purpose: Nutcracker syndrome, characterized by the compression of the left renal vein between the aorta and the superior mesenteric artery, is typically benign and self-limiting. However, prolonged venous stasis can increase the risk of renal vein thrombosis, although this complication is rare. Methods: We report the case of a patient who presented with flank pain and was diagnosed with both nutcracker syndrome and renal vein thrombosis. Results: Two days before hospitalization, the patient experienced sudden-onset left flank pain. A CT scan revealed left renal vein thrombosis, ipsilateral kidney enlargement, and tortuous venous collaterals in the left abdomen, consistent with nutcracker syndrome. Hematuria and proteinuria were not present, and the renal function was normal. During the workup for thrombophilia, the patient was found to have significantly reduced protein S activity (<10%). Genetic testing confirmed protein S deficiency due to a mutation in the PROS1 gene. As thrombolysis and thrombectomy were not feasible, the patient was initially treated with anticoagulation therapy, starting with heparin and transitioning to warfarin. Over time, follow-up imaging showed gradual improvement of the renal vein thrombosis, though it was not completely resolved. Ten months later, the anticoagulant was switched from warfarin to rivaroxaban (Xarelto). Given the underlying condition, the patient remained on long-term anticoagulation therapy. After four years, follow-up ultrasound confirmed complete resolution of the thrombosis, with renal function remaining stable Conclusion: Clinicians should be aware that patients with Nutcracker syndrome presenting with renal vein thrombosis require a comprehensive evaluation for underlying hypercoagulable conditions