Greenfield caval filters: long-term radiographic follow-up study

Area of Science:

• Vascular Surgery
• Radiology
• Medical Device Evaluation

Background:

• Inferior vena cava (IVC) filters are used to prevent pulmonary embolism.
• Long-term stability and potential complications of IVC filters require evaluation.
• Greenfield filters are a common type of IVC filter.

Purpose of the Study:

• To assess the long-term changes in Greenfield IVC filter position, span, and angle.
• To identify potential complications associated with filter migration or altered span.
• To evaluate the utility of abdominal radiography for IVC filter follow-up.

Main Methods:

• Retrospective analysis of 69 patients with Greenfield IVC filters.
• Evaluation using supine abdominal radiographs over 1-9 years.
• Assessment of filter span diameter, migration (caudad and cephalad), and angle from vertical.

Main Results:

• 32% of filters showed increased span (3-11 mm), 9% showed decreased span (3-18 mm).
• 29% experienced caudad migration (3-18 mm), 6% experienced cephalad migration.
• 7% of filters were tilted >16 degrees; potential complications include IVC occlusion and caval wall penetration.

Conclusions:

• Abdominal radiography is valuable for monitoring Greenfield IVC filters.
• Changes in filter span and angle can indicate potential complications.
• Regular radiographic follow-up is recommended to detect adverse events.