Single Institution Experience with Inferior Vena Cava Filters.
Authors: Bhalla Nikhil , Bulgaru Anca , Church Lynn , Kapur Dinesh , Lustberg Herb , Slater Dennis E. , Dhami Mandeep S. 
Published: April 2020

Abstract
Inferior vena cava (IVC) filters are used in patients (pts.) with Deep Venous Thrombosis (DVT) to prevent pulmonary embolism (PE) when anticoagulation cannot be administered. The purpose of this study was to analyze the use and outcomes of IVC filters in a community hospital. We reviewed the medical records of all pts. who had IVC filters implanted at William W. Backus Hospital between May 2003 and May 2005. Follow up information was obtained up to August 2005 by mailings from the attending physicians. 125 IVC filters were implanted in 121 pts., ages 18 to 93, with 61 males and 60 females. The indications for implantation were contraindication as follows: to anticoagulation in 72 pts. (58%), up coming surgical procedures in 33 pts. (26%), and severity of clot burden in 20 pts. (16%). 123 (98%) filters were deployed into an infrarenal position and 2 into a suprarenal position due to extensive clot in the IVC. Of the 105 filters that were not retrieved 60 were Gunther Tulip (GT) retrievable IVC filters, 42 were Cordis Trapease (CT) permanent IVC filters, 2 were stainless steel Greenfield IVC filters, and 1 was a Cordis Optease (CO) IVC filter. Of the 20 retrieved filters 19 were GT retrievable IVC filters and 1 was a CO IVC filter. Of the 125 filters, 74 were intended to be permanent filters (59%) and 51 (41%) were inserted with intention of retrieval. 31/51 (60%) were eventually not retrieved because of various reasons: need for additional surgery (12), poor pulmonary reserve (5), high-risk of bleeding (5), severity of clot burden (4), short life expectancy (4), and extremely high risk of recurrent DVT (1). Short-term and long-term anticoagulation was used in conjunction with the IVC filters in 21 and 81 pts. respectively. 38 (31%) of the 121 pts. experienced recurrent venous thromboembolism (VTE), 37 developed symptomatic DVT and 1 had a symptomatic PE. 3/20 (15%) of the pts. who had their filters retrieved developed recurrent DVT (18, 22, and 76 days after filter retrieval) compared with 34/105 (32%) pts. who had permanent filters. The only objectively documented symptomatic PE occurred in a pt. with a permanent filter. This pt. had a recurrent PE 7 months post GT IVC filter insertion diagnosed by chest CT scan with PE protocol. Complications were as follows: 1 pt. had transient hypertension immediately after IVC insertion and 1 pt. developed a transient low-grade fever after retrieval. 1 pt. developed retroperitoneal hematoma upon retrieval 75 days after implantation as documented by an IVC Gram and this pt. recovered without need for any intervention and there were no adverse clinical consequences. The implantation periods ranged from 2 to 104 days in the 20 retrieved filters with mean/median of 20/9 days. 4 of the 20 retrieved filters (20%) contained trapped emboli and none of these pts. subsequently developed PE. The GT retrievable IVC filter is now the filter of choice at our institution and can be implanted permanently or with retrieval in mind. Conclusion: Retrievable filters were removed up to 104 days post insertion in this series of pts. and the incidence of complications was negligible. Retrievable IVC filters may be substituted for permanent IVC filters to preserve the option of retrieval, and retrieval of filters beyond 3 months post implantation is feasible and should be studied further.