Study of Bard Vena Cava Filters finds Fracture Risk
The majority of vena cava filters used by the medical community to stop blood clots from traveling to the lungs are made by Bard. Accordingly, the Bard Recovery and Bard G2 vena cava filters were included in a study which determined that both of these filters are prone to fracturing inside the body. The study will be available to the general public in the November print issue of the Archives of Internal Medicine. This study reports that in several cases the fractured pieces of the broken filter travelled to the heart causing life threatening problems and sudden death.
Vena Cava filters are also known as IVC filters and have been available from Bard since April of 2003 as the Recovery filter. In October of 2005, Bard redesigned the original device as a result of reports of broken filters in several patients. The redesign was named the Bard G2 vena cava filter and was supposed to be better resistant to fracture. Since the G2 was introduced it has been implanted in roughly 65,000 patients. These filters are placed inside a large vein that returns blood to the heart from the lower body. The purpose of these devices was to trap clots before they enter the lungs.
The Archives of Internal Medicine study involved researchers evaluating patients who received either one of the Bard filters at York Hospital between 2004 and 2009. Of the 80 participating patients, 13 had at least one fracture from their filter. Seven of these cases were patients who had the first generation Recovery filter. In 5 of the 7 cases the fragment had traveled to the heart causing rapid heartbeat, fluid buildup and one case of sudden death.
Researchers also found that the patients receiving the Bard G2 filters experienced breakage. Six out of 52 patients had fractures. Two of the 6 experienced blocked blood flow, one leading to the liver and one in the lungs. In the other four patients, the fragments remained near the device.
The initial results seemed to show that the G2 was more reliable and less prone to fracture than the Recovery filter. However researchers pointed out that the assessment is not quite as black and white as it may seem. The Recovery filter had been implanted for an average of 50 months in those patients, and the Bard G2 filter had only been implanted for around 24 months. When the time frames were dissected, it appears that the time intervals for fracture of filters were about the same between the Recovery and the G2.
The study and researchers indicate that physicians and their patients should be educated and advised as well as work together to form a benefit risk evaluation before implanting an IVC filter. They should also discuss the possibility of removing the filter when the risk of blood clotting is resolved.