CASE 14201 Published on 14.11.2016

Malposition of IVC filter with perforation

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Priya Sarv, M. D., Aghayev Ayaz, M. D.

Department of Non-Invasive Cardiovascular Imaging, Brigham & Women's Hospital, Boston, MA, Email:spriya1@partners.org
Patient

80 years, male

Categories
Area of Interest Cardiovascular system ; Imaging Technique CT-Angiography
Clinical History
Case 1: 79-year-old man with history of hereditary hemorrhagic telangiectasias, atrial fibrillation, right calf DVT, with placement of Gunther Tulip IVC filter.

Case 2: 62-year-old female with a history of graft versus host disease, bilateral popliteal vein, and left tibial vein thrombosis, with placement of Cook Celect IVC filter.
Imaging Findings
Case 1: The IVC filter was seen in infrarenal part approximately 2 to 2.5 cm below the left renal artery draining into inferior vena cava. The IVC filter was tilted with its apex protruding outside the lumen of IVC and directed posteriorly and towards the left reaching behind the infrarenal aorta. No pseudoaneurysm or direct invasion into the aorta was seen. No retroperitoneal hematoma or strut fracture was seen.

Case 2: Axial and coronal reformatted CT image shows horizontal alignment of one of the strut of IVC filter that is projecting outside the wall of IVC and reaching upto the wall of aorta. No surrounding hematoma/thrombus was seen.
Discussion
The incidence of complications related to IVC filter placement varies from 4-11% [1]. The various early complications include tilting, malpositioning or abnormal deployment. Late complications include perforation, thrombosis, migration, fracture or recurrent pulmonary embolism. Majority of complications that are seen are found to be incidentally noted on CT scans done for other clinical reasons [2]. At our institution, CT scan is performed after administration of 125 mL of iodinated contrast agent (370 mg I/mL) at 100 and 180 seconds, with reconstruction at 1-mm slice thickness at 0.5-mm increments. Data is processed in a 3-D workstation using MPRs, MIPs, and volume-rendered images for the assessment of the site and associated complications. Ideally, the tip of the filter should be at the level of renal vein [3]. Additionally, the filter can be placed in a suprarenal location in patients with renal vein thrombosis or mega IVC (diameter > 28mm) [2, 4]. The filter may be malpositioned in other sites like renal veins, iliac veins or aorta. Preoperative CT is also important to look for venous anatomy like retroaortic or circumaortic left renal vein. The change in position of filter more than 2 cm either cranial or caudal to the normal position is defined as migration [5]. If the filter is displaced distant to the site of deployment e.g. in right atrium, it is termed as embolization [5]. Filter migration/embolization may result in patients with mega IVC [6]. Venous complications include caval thrombosis that may be due to extension of thrombus into IVC filter or due to metastasis extending into IVC. Perforation of filter is defined as strut seen extending more than or equal to 3 mm outside wall of IVC as seen on imaging, and may involve adjacent muscle or vertebrae [5]. Pulsation of the aorta and respiratory motion has been postulated as the main cause of caval perforation by the filter leg.[7] The loss of structural integrity of filter fragments is termed as fracture. It may result from excessive stress on a fragment if placed adjacent to vertebral osteophyte [8]. Tilting is defined as angulation of the filter by more than 15° in relation to the longitudinal axis of IVC. Take home point: Use of appropriate MDCT techniques with advanced imaging workstation provides an advantage in defining the abnormal pathology. Radiologists must keep a high level of suspicion even in asymptomatic patients to look for potential complications and subsequently advise a serial follow up whenever deemed necessary.
Differential Diagnosis List
Malpositioned IVC filter
Malpositioning of IVC filter
IVC Filter fracture
Final Diagnosis
Malpositioned IVC filter
Case information
URL: https://www.eurorad.org/case/14201
DOI: 10.1594/EURORAD/CASE.14201
ISSN: 1563-4086
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