Reply: Immortal time bias and the use of IVC filters (original) (raw)

Ins and outs of inferior vena cava filters in patients with venous thromboembolism: the experience at Monash Medical Centre and review of the published reports

Internal Medicine Journal, 2007

Background: Inferior vena cava (IVC) filters are an alternative management strategy to anticoagulation in patients with venous thromboembolism (VTE). However, an IVC filter has its own inherent risks and complications and may not be the best management strategy. The aims of this study were to evaluate our institution’s practice of permanent Vena Tech (B. Braun Medical S.A., Boulogne, France) and retrievable Gunther Tulip (William Cook Europe, Bjaeverskov) IVC filters and to review the available published reports.Methods: Retrospective single centre audit from the medical record.Results: Eighty-three and 42 patients had a VT and GT filter inserted, respectively. Median age was 57 years for VT and 63 years for GT. The majority (75% for VT and 83% for GT) was inserted for acute VTE and contraindication to anticoagulation. Both filters were efficacious at preventing pulmonary embolism (PE) and there was a low rate of recurrent deep venous thrombosis in both groups. Insertion-related complications were low in both groups. Of the GT filters (n = 42), 16 were deemed an ongoing requirement, and thus, removal was not planned. In a further six patients, there was insufficient documentation as to why removal was not planned. Removal was attempted in 19 patients and was successful in 11. Failure of removal was as a result of clot in the filter (n = 7) or inability to snare it (n = 1).Conclusions: Both the permanent and retrievable filters are efficacious at preventing PE and are associated with a low complication rate. Planned removal of the GT filter may not be possible in a significant proportion of cases.

High variation between hospitals in vena cava filter use for venous thromboembolism

JAMA internal medicine, 2013

The extent to which vena cava filter (VCF) use varies between hospitals in the management of acute venous thromboembolism (VTE) is not clear. We conducted a retrospective observational study that compared the frequency of VCF use among California hospitals from January 1, 2006, through December 31, 2010. Using administrative hospital discharge data, we followed explicit criteria to identify nontrauma patients with acute VTE, and determined the frequency of VCF placement in each of the hospitals that admitted more than 55 VTE patients. Multivariable hierarchical regression models to predict VCF use included important clinical and demographic variables as fixed effects and hospital as a random effect. Among the 263 hospitals included, 130 643 acute VTE hospitalizations occurred with the placement of 19 537 VCFs (14.95%). Variation in the percentage of acute VTE hospitalizations that included VCF placement was very high, from 0% to 38.96% (interquartile range, 6.23%-18.14%), with 18.49...

Indications and prognostic outcome of inferior vena cava filter: Almoosa Hospital's experience

Background An inferior vena cava (IVC) filter is useful in patients with venous thromboembolism (VTE) who have any of the following conditions: contraindications to anticoagulants, recurrent pulmonary embolism (PE) despite anticoagulants or complications related to anticoagulants, and low cardiopulmonary reserve. This study aimed to assess indications, efficacy, and outcome of IVC filter insertion for patients with VTE. Patients and methods A retrospective study was conducted at Almoosa Hospital, Al Alhsa, Kingdom of Saudi Arabia, in the period between August 2017 and September 2020. All adult patients who underwent IVC filter were included. Results The study included 1350 cases. The patients were divided into two groups: group 1 included 1310 patients who had VTE without the need for an IVC filter, and group 2 included 40 patients, 39 of whom had VTE and required an IVC filter, and one patient with polytrauma (cerebral hemorrhage, pelvic hematoma) in whom an IVC filter was used prophylactically. A total of 40 IVC filters were used. Thirty (75%) patients had submassive PE with pulmonary hypertension and low pulmonary vascular reserve, nine (22.5%) patients had VTE with contraindications for an anticoagulant (due to gastrointestinal bleeding, cerebral hemorrhage, or major trauma), while one (2.5%) patient had an IVC filter inserted prophylactically although no VTE was present. The rate of IVC removal was 30% (12 cases), with no reported complications of IVC insertion or removal, except in one case where the filter was removed in two separate sessions. Conclusion IVC filter insertion, when used correctly, is a safe and effective method of preventing a potentially fatal PE by blocking the passage of thrombi from the lower extremities and pelvis to the lungs when used correctly.