Discussion
IVC aneurysms are uncommon. It is only 54 cases reported in English
medical literature (1).The etiologies of IVC aneurysms remain unclear,
but in some acquired cases of IVC aneurysms trauma and inflammatory
processes are involved as causative factor. In addition, longstanding
systemic venous hypertension secondary to right side heart failure,
tricuspid valve lesions, cardiomyopathy, and constrictive pericarditis
may also contribute to the formation of IVC aneurysms. Moreover, IVC
aneurysms have been associated with embryogenic malformation such as
tetralogy of Fallot, azygous agenesis, membranous IVC obstruction and
left side IVC (1, 2, 4).
An aneurysm of IVC may present with the symptoms related to
complications such as thromboembolism or IVC syndrome or may have some
nonspecific abdominal or back pain. Although, uncomplicated aneurysm of
IVC may have no symptoms (1, 2, 4, 6). In our case, it was the diarrhea,
abdominal pain and lower extremity venous insufficiency which lead us to
the diagnosis. Imaging studies such as MRI angiography, CT angiography
and venography are diagnostic (2, 3, 4). Duplex ultrasonography is also
helpful. According to Gradman and Steinberg classification of IVC
aneurysms our case is a type III IVC aneurysm (5). Type II-IV IVC
aneurysms have high rate of complications such as thromboembolism and
rupture (1, 2, 3).
Management of IVC aneurysms entirely depends on their nature and
presence of complications (1, 3, 6). In our case we proceeded to perform
surgical resection of aneurysm because there was a high risk of
complications and there was a low probability of surgical complications.
The endovascular approach was discussed but was rejected because of the
risk of IVC rupture in case of huge oversizing of the endograft (in
order to avoid any endoleak). Moreover, a septic cause of the pseudo
aneurysm was not excluded.
In our case we did not find any past history of trauma. Additionally,
histopathologic and bacteriologic examinations of aneurysmal tissue
biopsy did not find any particular abnormality in favor of inflammatory
process and complementary examinations did not find any associated
congenital malformation. Therefore we presumed our case as spontaneous
(idiopathic).