Effect on Mortality With Inferior Vena Cava Filters in Patients Undergoing Pulmonary Embolectomy

Inferior Vena Cava Filters and Complications: A Systematic Review

Inferior vena cava (IVC) filters have been used since the 1960s to treat patients with acute risk of pulmonary embolism (PE) to prevent migration of thrombus by trapping it within the filter. Traditional usage has been in patients with contraindication to anticoagulation that carry a significant mortality risk. In this systematic review, we sought to evaluate complications associated with placement of inferior vena cava filters based on published data from the past 20 years. A search was performed on October 6th, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, using three databases (ProQuest, PubMed and ScienceDirect) for articles published between the dates of February 1, 2002 and October 1, 2022. Results were filtered to include full-text, clinical studies, and randomized trials written in English pertaining to keywords "IVC filter AND complications", "Inferior Vena Cava Filter AND complications", "IVC filter AND thrombosis" and "Inferior Vena Cava Filter AND thrombosis". Articles identified by the three databases were pooled and further screened for relevance based on inclusion and exclusion criteria. Initial search results yielded 33,265 hits from all three databases combined. Screening criteria were applied, with 7721 results remaining. After further manual screening, including removal of duplicate hits, a total of 117 articles were selected for review. While there are no consensus guidelines for best practice, there is compelling evidence that IVC filters can provide significant protection against PE with minimal complications if the treatment window is appropriate. Increase in the variety of filter models has led to broader availability, but skepticism remains about their efficacy and safety, with ongoing controversy surrounding appropriate indications. Further research is needed to establish clear guidelines on appropriate indications for IVC placement and to determine time course of complications versus benefits for indwelling filters.

Meta-Analysis of the Usefulness of Inferior Vena Cava Filters in Massive and Submassive Pulmonary Embolism

To conduct a systematic review and meta-analysis evaluating the safety and effectiveness of inferior vena cava filter (IVCF) placement in the setting of massive and submassive pulmonary embolism (PE), Pubmed and Cochrane Library were queried to identify all clinical studies evaluating IVCF placement in patients with massive and submassive PE from database establishment to December 2019. The rate of recurrent PE, PE-related mortality, adverse events, IVCF type, additional treatment intervention, DVT status, and follow-up length were retrieved. Recurrent PE, mortality, and complication rates were pooled. Meta-analysis was performed to compare mortality rates between groups with and without IVCF placement. Subgroup analysis was performed based on whether catheter-directed therapy was used for PE intervention. Fifteen observational studies with a total of 232 patients who received IVCF for submassive or massive PE were included. The pooled overall recurrent symptomatic PE and mortality rates were 1.4% and 5.5%, respectively. A lower mortality rate among patients with IVCF was observed than those without (6.8% vs 26.3%; odds ratio [OR] 0.275 [95% confidence interval] 0.090 to 0.839], I² = 30.6%, p = 0.023). Patients who received concurrent catheter-directed therapy demonstrated a lower recurrent PE (0% vs 2.8%) and mortality rate (3.4% vs 7.8%) than those who did not. The cumulative IVCF-related complication rate was 0.63%. In conclusion, based on a limited amount of low-quality evidence, IVCF placement is associated with low recurrent PE and PE-related mortality rates among patients with massive and submassive PE, suggestive of a potential clinical benefit in this scenario. Prospectively designed studies are warranted to confirm these findings.

Adjunctive Therapy and Mortality in Patients With Unstable Pulmonary Embolism

Mortality with adjunctive therapy in patients with unstable pulmonary embolism, defined as those in shock or on ventilator support, is sparsely studied and requires further investigation. This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample, 2016. In-hospital all-cause mortality in unstable patients with acute pulmonary embolism was assessed according to treatment. Patients were identified by International Classification of Diseases-10-Clinical Modification Codes. Most unstable patients, 85%, received only anticoagulants. Their mortality was 3,080 of 6,635 (46%) without an inferior vena cava (IVC) filter, and mortality was much less with an IVC filter, 285 of 1,185 (24%) (p <0.0001). Mortality with catheter-directed thrombolysis alone, 70 of 235 (30%), did not differ significantly from mortality with anticoagulants plus an IVC filter, p = 0.07, although a trend favored the latter. Intravenous thrombolytic therapy without an IVC filter showed a mortality of 295 of 695 (42%) which tended to be lower than mortality with anticoagulants alone (p = 0.06). The addition of an IVC filter to intravenous thrombolytic therapy resulted in a mortality of 20 of 165 (12%), which was the lowest mortality with any combination of adjunctive treatments. Intravenous thrombolytic therapy, however, was associated with more adverse effects of therapy than catheter-directed thrombolysis or anticoagulants.