Effectiveness of Inferior Vena Cava Filter Departmental Follow-Up Form to Improve Filter Retrieval Rates: a Single-Center Experience

Background: Inferior vena cava (IVC) filter is a device inserted in patients who are prone to develop pulmonary embolism (PE) and deep venous thrombosis (DVT). PE and DVT are one of the most common medical conditions present in patients who have venous thromboembolism. Venous thromboembolism begins as DVT in the lower limbs which detaches and travels through IVC. The clot ends up as PE blocking the heart and lung circulation. One in 10,000 people are diagnosed with PE and increases to 5 in 1000 by the age of 80 annually. PE leads to hypopnea, chest pain, tachycardia, and in severe cases heart failure, loss of consciousness, and death. In the United States, 25%–40% of cases reported with sudden death. The first line of the treatment is anticoagulants and blood thinning medications. Some neurological and cardiovascular conditions limit the efficacy of anticoagulants. Therefore, IVC filters are used as second-line treatment. In 1973, the first filter was used to replace surgical interventions to prevent thrombosis. The IVC filter has a conical shape ending with hooks to anchor it to the IVC wall. An effective filter has easy placement and can trap all thrombi to prevent new or recurrent PE without migration or perforation of IVC. IVC filter is mainly indicated when anticoagulation therapy is not effective, as in patients with trauma, hemorrhage, and other cardiac problems. However, it cannot be used in severe uncorrectable coagulopathy, prothrombotic state, and active bacteremia. IVC filters are designed with different durability, permanent, and retrievable, according to the patients' conditions. Permanent filters were mainly used in the past until retrievable filters were approved by the Food and Drug Administration (FDA) in 2003. Although retrievable filters are designed to be removed, in some cases, they become permanent due to lack of patient's compliance or poor monitoring. In Wellington Hospital, out of 5000 patients with IVC filters only 12%–45% of filters were retrieved. No local studies, in Saudi Arabia, are available. Leaving the filter longer than necessary may lead to several complications. The longer the filters are left in the body, the greater the chances that migration and malposition will occur. This tilting, or malpositioning, can result, in less common cases, in filter fracture. Failed retrieval can also be caused by a trapped clot. When more than 25% of the filter is filled with a clot, it cannot be removed. Instead, the patient is given anticoagulants for the following 1–2 months, the filter removal attempt is then repeated. Other long-term complications include IVC perforation, IVC occlusion, and developing DVT. To prevent further long-term placement complications that counter-affect the main purpose of inserting filters, the FDA urged health institutions to maximize the retrieval rates. At King Abdulaziz Medical City, the Vascular and Interventional Radiology department established a departmental form in January 1, 2015, to improve retrieval rates of IVC filters. The purpose of the study to compare retrieval rates before and after implementing the form to access its effectiveness. Methods: This is a case–control retrospective study of all patients who had retrievable IVC filter insertion 2 years before and after implementation of a departmental follow-up from June 2015. The departmental follow-up form includes the following information: Patient's name, age, sex, and medical record number. It also contains most responsible physician badge number and pager. IVC filter date of insertion and removal, filter type, and implementing physician name are also included. Subjects were retrospectively analyzed based on age, gender, indication, type of filter, date of filter insertion, location of insertion, date of retrieval, dwelling time, and previous attempts of retrieval. Results: Between June 2013 and May 2017, a total of 307 filters were inserted in 183 males (59.61%) and 124 females (40.39%) with mean age of 59 (SD 17.24). Of these filters, 296 (96.42%) were placed in an infrarenal location and 11 (3.58%) were placed as suprarenal filters. The types of the filters were as follows: 167 Optease (54.40%), 33 Option Elite (10.75%), 78 Denali (25.41%), 2 Capturex (0.65%), and 27 Celect (8.79%). A total of 148 (48.21%) filters were inserted before establishing the follow-up form, and 159 (51.79%) were inserted after the form. A total of 53 (35.81%) of those filters inserted before the form were retrieved, while 61 filters (38.36%) of those inserted after the form were. The mean dwelling time of retrieved filters before the form was 32 days and 48 days for the 2 years after the form implementation, with a standard deviation of 49.42. This increase was explained by the use of filters with longer dwelling time. Filter retrieval was successful in 110 patients (96.49%) from the first attempt and four patients (3.51%) required more than one attempt Conclusion: The departmental follow-up of patients who undergo IVC filters results in improvement of the retrievability rates.

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Artikel online veröffentlicht:
11. Mai 2021