The main function of a<unk> <unk><unk>  is to prevent death from massive pulmonary emboli. Long-term clinical follow-up studies have shown that this is accomplished in 96% of cases having a standard stainless-steel Greenfield<unk> . Abdominal radiograph shows that one of the legs (arrows) of the<unk><unk>  is pointed away from the expected IVC lumen. Axial CT image confirms that one of the legs (arrow) of the<unk><unk>  has migrated out of the IVC wall into an adjacent tissue. FDA communication In August, 2010, the FDA released an Initial Communication on the Risk and Adverse events associated with Long Term use of an<unk> . Over a period of about 5 years, they identify 921 events. While not the majority of cases, that number still represents a statistical significance of the use of long-term IVCs. Of these<unk><unk>  side effects, 328 involved device migration, 146 involved embolizations after detachment of device components, 70 involved perforation of the IVC, and 56 involved<unk>  fracture. Much of the medical community believes that this large number of adverse events is related to the heart<unk>  remaining in place for longer than necessary. Common issues relating to failure, to include death (the other 4% of cases) include: * Device-associated morbidity * Device migration *<unk>  embolization *<unk>  fracture * Insertion-site thrombosis * Perforation of the<unk> <unk>  * Recurrent DVT * Recurrent PE * Thrombotic complications *<unk> <unk>  thrombosis Less common adverse reactions While these side effects are not common (less than 10-20% of patients), many do report issues stemming from the placement and complication of the IVC while inside of the body. * 9% (12 of 132 patients) delayed<unk>  penetration of the IVC greater than 3 mm * Parts of<unk>  broke off in 2% (5 of 230 patients) *<unk> l<unk>  migrated to heart or pulmonary artery (4 patients) Numerous small published articles and case studies report describe similar issues to the above. Most notably: *<unk>  fracture: Broken struts migrate to retroperitoneum, requiring exploration. Also struts can migrate to the heart and can cause pericardial effusion and tamponade. * Perforation into the duodenum: Resulting in severe diarrhea and weight loss. * Arterial hemorrhage: Requires surgery to avoid death. * Misplaced<unk> : Causes pericardiac tamponade requiring surgery under cardiopulmonary bypass. *<unk>  Migration to Right Atrium: Resulting in acute myocardial infarction. *<unk>  Lodged in Heart: Causes life-threatening arrhythmia and often requires pacemakers to resolve condition. * Heart Migration: Requires surgery to remove<unk> rom heart. * Sudden Death: Caused by the<unk>  migrating to an active region in the heart. * Migration of<unk>  to Chest: Requires surgery. * Perforation of<unk>  strut into small-bowel: Requires surgery to repair perforation. Even though the cases above are the exception, and not the rule, most radiologists object to doing prophylactic<unk>  insertions in patients who do not have thromboembolic diseases. For the most part, whenever possible, interventional radiologists would rather start the patient on anticoagulants than use an IVC, even if requested or referred via a doctor. MRI While most<unk><unk> s are made of non-ferromagnetic materials, there are a few types that are weakly ferromagnetic. Accordingly,<unk><unk> s fall under the MRI Safe and MRI Conditional categories depending mostly on type of material used during construction. Rarely will one find an MRI Not Safe<unk><unk> , as most of the steel, and other ferromagnetic material devices have been discontinued via the FDA.<unk><unk> s are attached to the<unk> <unk>  via hooks on their ends. Some are compression springs, which compress outward onto the side wall of the<unk> <unk> ; however, they still have small hooks that retain their location. These hooks aid in the anchoring and healing process, as they allow the tissues to 'ingrow' around them, securing the IVC in place. It is unlikely, then, after 4 to 6 weeks of healing, that an MRI of 1.5 tesla, up to 3 tesla, will cause any level of dislodging to occur to the<unk><unk> . Studies of MR examination of both animals and humans, with implanted<unk><unk> s, have not reported complications or symptomatic<unk>  displacement. Several animal studies have even used "real-time" MR for the placement of<unk><unk> s to check for rotation, sheering, and other artifacts. As part of the 'routing' survey for MRI studies, patients who have<unk><unk> s will often need verification from the doctor, or medical records, to state that the IVC is safe for the MRI. Most patients with weakly or non-safe ferromagnetic implants will be given a card, which they keep on their person at all time, that can help isolate if it is safe to do an MRI. For patients who have been denied MRI scans for safety reasons, doctors usually recommend the CT scan with contrast as an alternative. Labeling and recommendations Most<unk><unk> s that have been tested have been labeled as “MRi safe”; the remainder of<unk><unk> s that have been tested are “MR conditional.” Patients who have been treated with nonferromagnetic<unk><unk> s can undergo MR examination any time after<unk>  implantation. In patients who have been treated with a weakly ferromagnetic<unk><unk>  (Gianturco bird nest<unk><unk>  Cook, stainless steel Greenfield<unk> <unk><unk>  Boston Scientific), it is advised that the patient wait at least six weeks before undergoing an MR examination (because these older devices initially may not be anchored as firmly in place as other devices discussed in the present context), unless there is a strong clinical indication to perform the MR examination sooner after implantation, and as long as there is no reason to suspect that the device is not positioned properly or that it is not firmly in place. Most studies of<unk><unk> s have generally been conducted at 1.5 tesla or less, although many<unk><unk> s have now been evaluated at 3 tesla and deemed acceptable for MR examination.
Inferior vena cava filter
Pulmonary thromboendarterectomy
Thrombectomy
Low-molecular-weight heparin
Pulmonary thrombectomy
Endarterectomy
Endovascular aneurysm repair
Carotid endarterectomy