|LETTER TO THE EDITOR
|Year : 2016 | Volume
| Issue : 3 | Page : 131-132
Intramural inferior vena cava occlusion: The minaret sign
Shaileshkumar S Garge MD, DNB , Shyamkumar N Keshava
Department of Radiology, Christian Medical College, Vellore, India
|Date of Submission||11-May-2016|
|Date of Acceptance||21-Jun-2016|
|Date of Web Publication||27-Feb-2017|
Shaileshkumar S Garge
FVIR Interventional Radiology, Radiology Office, Department of Radiology, Christian Medical College, Vellore 632004
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Garge SS, Keshava SN. Intramural inferior vena cava occlusion: The minaret sign. Egypt J Intern Med 2016;28:131-2
| Introduction|| |
We describe an interesting imaging finding in a patient with inferior vena cava (IVC) occlusion or severe stenosis due to an intramural cause as the ‘Minaret sign’. This appearance in IVC occlusion or severe stenosis is due to caudal dilation of the IVC and the progressive merging of the IVC wall cranially at one point as observed in the IVC ultrasound (US) ([Figure 1]a) and the IVC digital subtraction venogram (DSV) ([Figure 1]b), resembling the appearance of a Minaret, that is, ‘the Minaret sign’.
|Figure 1 IVC occlusion causing caudal dilation of the IVC and progressive merging of the IVC wall cranially at one point as observed in the sagittal IVC ultrasound (a) and the IVC digital subtraction venogram (b), resembling the appearance of a Minaret. IVC, inferior vena cava.|
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| Case|| |
A 42-year-old male patient presented with abdominal pain, ascites, and pedal edema. The complete blood count, the liver function test, and renal function tests were normal. An US and Doppler of the abdomen revealed a short segment of occluded intrahepatic IVC at the level of hepatic venous confluence, caudal dilation of the IVC with convex outer margins, and progressive merging of the IVC wall till the point of occlusion. DSV confirmed the US and Doppler findings. No obvious cause of occlusion could be identified. Balloon angioplasty of the occlusion was performed. The patient improved significantly with complete resolution of abdominal pain, ascites, and pedal edema. Informed consent was obtained from the patient.
| Discussion|| |
IVC occlusion is not an uncommon condition and is often associated with debilitating symptoms that vary depending on collateral venous drainage . The causes of IVC occlusion can be divided into extramural/extrinsic, intramural, and intraluminal. US, Doppler, computed tomography venogram, magnetic resonance venogram, and DSV can be used in the imaging of IVC occlusion . The imaging appearance of IVC occlusion can vary depending on the cause, such as narrowing/occlusion, caudal dilation, collaterals veins, membrane, etc.
Membranous obstruction of the intrahepatic IVC accounts for most cases of primary Budd–Chiari syndrome (BCS) in Asia. It is typically a disease of adulthood with an insidious onset and a chronic course that eventually leads to congestive cirrhosis . In contrast, in most western nations, BCS results from hepatic venous thrombosis due to an underlying prothrombotic state, has an acute onset, and is often fatal. The cause of membranous obstruction of the intrahepatic IVC remains unclear in the majority of the cases; however, there is mounting evidence that it is a sequelae of IVC thrombosis . England et al.  reported cases of benign external compression of the IVC associated with thrombus formation, where the extrinsic compression on the IVC had a ‘slit-like’ appearance. This report provides much enlightenment on uncommon causes of IVC compression and thrombus formation.
We emphasize that the ‘Minaret sign’ helps differentiate intramural causes from other extramural/extrinsic causes such as a hypertrophied caudate lobe ([Figure 2]) in BCS, where we expect to notice concave outer margins with a slit-like lumen as interventional options in BCS can vary depending on the cause .
|Figure 2 Caudate lobe hypertrophy causing side-to-side narrowing of the intrahepatic IVC. (a) The axial ultrasonography image showing the side-to-side slit-like narrowing of the hepatic IVC. (b) Sagittal Doppler with a spectral waveform showing continuous phasic flow in IVC. (c) A digital subtraction venogram showing a slit-like narrowing of the hepatic IVC with no caudal dilation. IVC, inferior vena cava.|
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| Learning point|| |
The ‘Minaret sign’ helps differentiate intramural causes from other extramural/extrinsic causes such as a hypertrophied caudate lobe in BCS, where we expect to notice concave outer margins with a slit-like lumen as interventional treatment options in BCS can vary depending on the cause.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
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Terabayashi H, Okuda K, Nomura F, Ohnishi K, Wong P. Transformation of inferior vena caval thrombosis to membranous obstruction in a patient with the lupus anticoagulant. Gastroenterology 1986; 91:219–224.
England RA, Wells IP, Gutteridge CM. Benign external compression of the inferior vena cava associated with thrombus formation. Br J Radiol 2005; 78:553–557.
Keshava SN, Moses V, Surendrababu NR. Cannula-assisted and transabdominal ultrasound-guided hepatic venous recanalization in Budd Chiari syndrome: a novel technique to avoid percutaneous transabdominal access. Cardiovasc Intervent Radiol 2009; 32:1257–1259.
[Figure 1], [Figure 2]