Discussion
Inferior vena cava thrombosis (IVCT) in a congenitally normal patient is rare and is usually a result of a predisposing hypercoagulable state along with an acquired pathology in the IVC or one of its adjacent structures.8-11 Etiologically, there are prothrombotic factors such as thrombophilia, malignancy, oral contraceptives, smoking, obesity, pregnancy, hormonal replacement therapy, and nephrotic syndrome. Besides these, there are abdominal pathologies such as renal cell tumor, abdominal masses producing extrinsic compression such as a very large uterine fibroid, Budd-Chiari syndrome, abdominal trauma/surgery, May-Thurner syndrome, and thrombotic occlusion of an IVC filter. Meanwhile, a recent study has shown local problems such as IVC anomalies contribute 11.3 percent, external venous compression contributes 11.3 percent, malignancy contributes 17.0 percent, and the presence of lupus anticoagulants contributes 10.9 percent to the risk of IVCT.12 There are some interesting clinical aspects in our case report. He was a congenitally normal IVCT patient who didn’t relate to the aforementioned etiologies and differed from them in all aspects. He had a sudden onset of symptoms related to venous thromboembolism. The only medical history he had was of hypertension, which was well managed by anti-hypertensive medication. We observed a high level of serum homocysteine, which was a new observation for us.
The association between deep vein thrombosis and hyperhomocystinemia was first reported in 1991, and since then a large number of prospective and retrospective trials have established a relation between hyperhomocysteinemia and deep vein thrombosis.13 Mild hyperhomocysteinemia appears to be an independent risk factor for arterial vascular disease and thromboembolic risk factors.14 Homocysteine levels can be raised by altered methionine metabolism, which can occur as a result of genetic defects affecting transcription of enzymes responsible for homocysteine metabolism. Many other factors, such as age, smoking, renal impairment, diabetes mellitus, hypothyroidism, and other nutritional deficiencies of folic acid, vitamin B6, and vitamin B12, and drugs such as phenytoin, carbamazepine, and methotrexate, may be linked to hyperhomocystinemia.13,15Interestingly, we describe a rare case of IVCT with no identifiable risk factors contributing to IVCT except hyperhomocysteinemia, which captures the attention.