There have been few case reports with IVC anomalies and development of deep vein thrombosis. In our comprehensive English language literature review, the earliest reported case of duplication of the inferior vena cava was reported in 1912 in the journal, The Anatomical Record. [6] Over the last 100 years, case series involving IVC duplication in association with venous thromboembolism number less than 10.
This observation was made following an extensive PubMed literature search encompassing the following keywords: inferior vena cava, congenital, deep venous thrombosis, and pulmonary embolism. From an anatomical standpoint in adults, IVC has 3 segments of different embryologic origin: pre-renal, renal, and post-renal. This type of fusion and partial re-absorption of three pairs of vessels is dependent upon the posterior cardinal veins in the embryo. This complicated evolutionary process can give rise to anatomic malformations that impede vein drainage and favor the development of thrombosis. [7, 8]
Duplication of the IVC, the prominent manifestation in our case report, occurs because the left supracardinal vein fails to regress early in gestation resulting in large veins on both sides of the Aorta that usually joins anterior to the level of the renal arteries to become the suprarenal IVC. [9] When incidentally found, treatment options include observation, placing filters in either systems, or coil-embolization of the duplicated segment plus placing a filter in the right IVC.
Furthermore, radiographic duplication of the IVC can be confused with saccular aortic aneurysms, aorto-lumbar lymphadenopathy, left pyeloureteric dilatation, retroperitoneal cysts, and loops of small bowel. [10] As a result it is imperative to consider this anomaly both in an acute presentation of venous thromboembolism in a younger individual, and with the above-mentioned disorders as well. A schematic diagram of the observed abnormality is shown in Figure 4.
As noted in our literature search, there were a few case reports of thromboembolic disease in patients with a duplicated IVC. In patients with DVT of the legs in this setting, the treatment paradigm protocol changes, caval interruption becomes paramount. The failure to interrupt both the right- and left-sided IVC can result in recurrent pulmonary embolism. [10] Physicians need to be reminded that such anomalies of the IVC exist and that they may influence decision-making in patients with an acute presentation of thromboembolic disease.
In all studies, age of presentation of first thrombosis has been less than 30 years of age and incidence is similar in men and women. Few studies [10–12] consider double inferior vena cava to be the cause of DVT, perhaps because it causes retrograde stasis less often. Compensatory drainage thru the thoracic-lumbar, pelvic, and abdominal veins can cause symptoms in the thorax, hypogastrium, lumbar, and genital regions, prior to those typical of DVT of the lower extremities. Early detection could warn of the presence of cava malformations in young patients. For instance our patient presented complaining of chest and abdominal pain, with associated discoloration of her left lower limb.
Some authors believe cava malformation alone can provoke DVT, [13] but the fact that lifelong asymptomatic malformations occur, [12] the findings in the case report and the status of thrombosis as a multifactorial illness, [14] suggest the presence of associated factors, both congenital and acquired. The complementary entities of the patient's heterozygosity for the Factor V Leiden mutation, and her use of an oral contraceptive intrauterine device, could invariably have been adjunctive triggers in her clotting cascade.
Ultimately there is currently no data available to guide the use of anticoagulation in the under 30 population who present with the additional complication of a congenital anomaly. Apparently, the most appropriate approach to treatment is for more than six months' anticoagulation while the principal factor provoking thrombosis continues. In conclusion, the possibility of recurrent thrombotic occlusion is high in these patients when anticoagulation treatment is withdrawn even when precipitating triggers such as oral contraceptives are removed.