Technical efficiency, short-term clinical results and safety of a large-bore aspiration catheter in acute pulmonary embolism - A retrospective case study

Comparison of Safety and Efficacy of Aspiration Thrombectomy and Ultrasound Accelerated Thrombolysis for Management of Pulmonary Embolism: A Systematic Review and Meta-Analysis

PURPOSE

To compare the safety and efficacy of mechanical thrombectomy (MT) and ultrasound-accelerated thrombolysis (USAT) in pulmonary embolism (PE) management by performing a systematic review of the literature.

MATERIALS AND METHODS

The PubMed database was searched to identify articles on Inari's FlowTriever and Penumbra's Indigo mechanical thrombectomy devices (Group A) and the Ekos Endovascular system (Group B). Outcomes variables analyzed include pre- and post-procedure RV/LV ratio, pre- and post-procedure pulmonary artery pressure, hospital length of stay, technical success, specific complications, and mortality rate. Mean values were calculated using the weighted mean approach. RevMan Version 5.4 (Cochrane Collaboration) was used to perform the meta-analysis for this study. Cochrane Collaboration's Risk of Bias (RoB 2.0) approach was used to perform a quality assessment of the included articles in order to verify the validity and reliability of the research.

RESULTS

27 studies were in Group A and 28 studies pertained to Group B. There were 1662 patients in Group A and 1273 patients in Group B. Both groups had similar technical success (99.6% vs 99.4%). Thrombectomy showed longer mean procedure time (73.03 ± 14.57 min vs 47.35 ± 3.15 min), lower mean blood loss (325.20 ± 69.15 mL vs 423.05 ± 64.95 mL), shorter mean ICU stay (2.35 ± 1.64 days vs 3.22 ± 1.27 days), and shorter mean overall hospital stay (6.94 ± 4.38 days vs 7.23 ± 2.31 days). EKOS showed greater mean change in Miller Index (9.05 ± 3.35 vs 4.91 ± 3.70) and greater mean change in pulmonary artery pressure (14.17 ± 6.35 mmHg vs 8.11 ± 4.39 mmHg).

CONCLUSION

Ultrasound accelerated thrombolysis and percutaneous mechanical thrombectomy are effective therapies for pulmonary embolism with comparable clinical outcomes.

Catheter-directed therapy with the FlowTriever system for intermediate-high and high-risk pulmonary embolism: a single-centre experience

BACKGROUND

Pulmonary embolism is an important cause of preventable mortality. Treatment strategies depend on risk stratification. High-risk patients, and some intermediate-high-risk patients, require urgent reperfusion therapy. Systemic thrombolysis (ST) is the effective first-choice treatment in these patients; however, the high risk of bleeding complications is a major drawback. In this single-centre retrospective cohort study, we report our experience with the FlowTriever thrombosuction system as an alternative or adjunct to ST in intermediate-high and high-risk pulmonary embolism.

METHODS

Demographic and clinical data of all patients treated with the FlowTriever system from December 2021 until March 2024 were retrieved from the electronic medical records. Primary outcomes were technical success rate, 30-day all-cause mortality and major bleeding.

RESULTS

Twenty-one patients were treated with the FlowTriever system, 14 of whom were considered high risk. The technical success rate was 100%. Thirty-day all-cause mortality was 29% and major bleeding was recorded in 5 patients (24%), of which one bleeding event was related to the FlowTriever procedure. A significant reduction was seen in mean pulmonary arterial pressure and right ventricular end-diastolic dimension.

CONCLUSION

In intermediate-high and high-risk pulmonary embolism patients with ST treatment failure or a contraindication for ST, the FlowTriever thrombosuction system seems to be a minimally invasive alternative treatment modality with low complication rates.

Acute Appendicitis Due to Enterobius vermicularis Infestation: A Case Report

Acute appendicitis is the most frequent abdominal surgical emergency worldwide. While luminal obstruction due to fecaliths and lymphoid hyperplasia is a common cause, parasitic infections are a rare but significant contributor. Enterobius vermicularis, the most common helminthic infection in developed countries, can trigger appendiceal inflammation through a mechanical obstruction or immune response. This report presents a case of a 16-year-old male with acute appendicitis secondary to E. vermicularis infestation. The patient presented with typical appendicitis symptoms, and laparoscopic appendectomy revealed the parasitic involvement, confirmed by histopathology. Postoperative recovery was uneventful following surgical intervention and anti-helminthic treatment. E. vermicularis is often an incidental finding in appendectomy specimens but may play a pathogenic role in some cases of appendicitis. This case underscores the importance of considering parasitic infections in patients with atypical presentations of appendicitis and highlights the value of histopathological examination in appendectomy cases.

Episode Care Costs Following Catheter-Directed Reperfusion Therapies for Pulmonary Embolism: A Literature-Based Comparative Cohort Analysis

This analysis aimed to estimate 30-day episode care costs associated with 3 contemporary endovascular therapies indicated for treatment of pulmonary embolism (PE). Systematic literature review was used to identify clinical research reporting costs associated with invasive PE care and outcomes for ultrasound-accelerated thrombolysis (USAT), continuous-aspiration mechanical thrombectomy (CAMT), and volume-controlled-aspiration mechanical thrombectomy (VAMT). Total episode variable care costs were defined as the sum of device costs, variable acute care costs, and contingent costs. Variable acute care costs were estimated using methodology sensitive to periprocedural and postprocedural resource allocation unique to the 3 therapies. Contingent costs included expenses for thrombolytics, postprocedure bleeding events, and readmissions through 30 days. Through February 28, 2023, 70 sources were identified and used to inform estimates of 30-day total episode variable costs. Device costs for USAT, CAMT, and VAMT were the most expensive single component of total episode variable costs, estimated at $5,965, $10,279, and $11,901, respectively. Costs associated with catheterization suite utilization, intensive care, and hospital length of stay, along with contingent costs, were important drivers of total episode costs. Total episode variable care costs through 30 days were $19,146, $20,938, and $17,290 for USAT, CAMT, and VAMT, respectively. In conclusion, estimated total episode care costs after invasive treatment for PE are heavily influenced by device expense, in-hospital care, and postacute care complications. Regardless of device cost, strategies that avoid thrombolytics, reduce the need for intensive care unit care, shorten length of stay, and reduce postprocedure bleeding and 30-day readmissions contributed to the lowest episode costs.

Mechanical thrombectomy is associated with shorter length of hospital stay and lower readmission rates compared with conservative therapy for acute submassive pulmonary embolism: a propensity-matched analysis

PURPOSE

To determine if mechanical thrombectomy (MT) for submassive pulmonary embolism (PE) positively impacts length of hospital stay (LOS), intensive care unit stay (ICU LOS), readmission rate, and in-hospital mortality compared with conservative therapy.

METHODS

This was a retrospective review of all patients with submassive PE who either underwent MT or conservative therapy (systemic anticoagulation and/or inferior vena cava filter) between November 2019 and October 2021. Pediatric patients (age <18) and those with low-risk and massive PEs were excluded from the study. Patient characteristics, comorbidities, vitals, laboratory values (cardiac biomarkers, hospital course, readmission rates, and in-hospital mortality) were recorded. A 2:1 propensity score match was performed on the conservative and MT cohorts based on age and the PE severity index (PESI) classification. Fischer's exact test, Pearson's χ2 test, and Student's t-tests were used to compare patient demographics, comorbidities, LOS, ICU LOS, readmission rates, and mortality rates, with statistical significance defined as P < 0.05. Additionally, a subgroup analysis based on PESI scores was assessed.

RESULTS

After matching, 123 patients were analyzed in the study, 41 in the MT cohort and 82 in the conservative therapy cohort. There was no significant difference in patient demographics, comorbidities, or PESI classification between the cohorts, except for increased incidence of obesity in the MT cohort (P = 0.013). Patients in the MT cohort had a significantly shorter LOS compared with the conservative therapy cohort (5.37 ± 3.93 vs. 7.76 ± 9.53 days, P = 0.028). However, ICU LOS was not significantly different between the cohorts (2.34 ± 2.25 vs. 3.33 ± 4.49, P = 0.059). There was no significant difference for in-hospital mortality (7.31% vs. 12.2%, P = 0.411). Of those that were discharged from the hospital, there was significantly lower incidence of 30-day readmission in the MT cohort (5.26% vs. 26.4%, P < 0.001). A subgroup analysis did not demonstrate that the PESI score had a significant impact on LOS, ICU LOS, readmission, or in-hospital mortality rates.

CONCLUSION

MT for submassive PE can reduce the total LOS and 30-day readmission rates compared with conservative therapy. However, in-hospital mortality and ICU LOS were not significantly different between the two groups.

Cardiovascular collapse during mechanical thrombectomy for acute pulmonary embolism and the role of extracorporeal membrane oxygenation in patient rescue

BACKGROUND

Driven by the ability to avoid thrombolytics and provide a one stop procedure with immediate hemodynamic improvement, there has been a dramatic increase in the use of mechanical thrombectomy (MT) devices for the treatment of intermediate-to-high risk pulmonary embolism (PE). This study investigated the incidence and outcomes of cardiovascular collapse during MT procedures and demonstrates the role of extracorporeal membrane oxygenation (ECMO) in salvaging patients.

METHODS

This single-center retrospective review included patients with PE undergoing MT with the FlowTriever device between 2017 and 2022. Patients presenting periprocedural cardiac arrest were identified and their perioperative characteristics and postoperative outcomes were evaluated.

RESULTS

A total of 151 patients with a mean age of 64 ± 14 years who presented with intermediate-to-high risk PE received LBAT procedures during the study period. The simplified PE severity score was ≥1 in 83% of cases and the average RV/LV ratio was 1.6 ± 0.5, with and elevated troponin in 84%. Technical success was achieved in 98.7% and a significant decrease in pulmonary artery systolic pressure (PASP) was observed (37 mm Hg vs 56 mm Hg; P < .0001). Intraoperative cardiac arrest occurred in nine patients (6%). These patients were more likely to present PASP of ≥70 mm Hg (84% vs 14%; P < .001), were more hypotensive upon admission (systolic of 94 ± 14 mm Hg vs 119 ± 23 mm Hg; P = .004), presented lower oxygen saturation levels (87 ± 6% vs 92 ± 6%; P = .023) and were more likely to present with a history of recent surgery (67% vs 18%; P = .004). Four patients were rescued successfully with ECMO and their residual PE was subsequently removed before discharge by surgical embolectomy in two of the four cases and repeat MT in the other two. All five patients (3%) who did not receive ECMO support expired intraoperatively. The overall 30-day mortality was 8% with no death occurring in patients who were salvaged with ECMO.

CONCLUSIONS

Large-bore aspiration thrombectomy for acute PE is associated with favorable technical outcomes, but the concern for acute cardiac decompensation is non-negligible in patients presenting with high-risk features and a PASP of ≥70 mm Hg. ECMO can help to salvage some of these patients and should be considered in the treatment algorithms of patients deemed at high risk.

Percutaneous thrombectomy in patients with intermediate- and high-risk pulmonary embolism and contraindications to thrombolytics: a systematic review and meta-analysis

Catheter-directed interventions have slowly been gaining ground in the treatment of pulmonary embolism (PE), especially in patients with increased risk of bleeding. The goal of this study is to summarize the evidence for the efficacy and safety of percutaneous thrombectomy (PT) in patients with contraindications to systemic and local thrombolysis. We performed a systematic review and meta-analysis using MEDLINE, Cochrane, Scopus and the Web of Science databases for studies from inception to March 2022. We included patients with intermediate- and high-risk PE with contraindications to thrombolysis; patients who received systematic or local thrombolysis were excluded. Primary endpoint was in-hospital and 30-day mortality, with secondary outcomes based on hemodynamic and radiographic changes. Major bleeding events were assessed as a safety endpoint. Seventeen studies enrolled 455 patients, with a mean age of 58.6 years and encompassing 50.4% females. In-hospital and 30-day mortality rates were 4% (95% CI 3-6%) and 5% (95% CI 3-9%) for all-comers, respectively. We found a post-procedural reduction in systolic and mean pulmonary arterial pressures by 15.4 mmHg (95% CI 7-23.7) and 10.3 mmHg (95% CI 3.1-17.5) respectively. The RV/LV ratio and Miller Index were reduced by 0.42 (95% CI 0.38-46) and 7.8 (95% CI 5.2-10.5). Major bleeding events occurred in 4% (95% CI 3-6%). This is the first meta-analysis to report pooled outcomes on PT in intermediate- and high-risk PE patients without the use of systemic or local thrombolytics. The overall mortality rate is comparable to other contemporary treatments, and is an important modality particularly in those with contraindications for adjunctive thrombolytic therapy. Further studies are needed to understand the interplay of anticoagulation with PT and catheter-directed thrombolysis.

Successful percutaneous catheter-directed treatment of high-risk pulmonary embolism: a case report

Background

Pulmonary embolism (PE) is an acute cardiovascular syndrome characterized by high incidence and mortality. The therapy of this condition is based on anticoagulation and hemodynamic support, but in case of high-risk mortality, the European Society of Cardiology (ESC) guidelines recommend systemic thrombolytic therapy and surgical embolectomy if thrombolysis is contraindicated or has failed; nowadays several percutaneous catheter-directed treatments for local thrombolysis or mechanical embolectomy are available, but they have IIa class of recommendation, because of lack of robust scientific evidence favoring their use.

Case Description

We described a case of high-risk PE treated with a novel percutaneous system for mechanical embolectomy, which consists of a large aspiration catheter that was advanced in the pulmonary artery, capturing and removing a vast thrombus, of 15 centimeters in length. This therapeutic strategy avoided the risk of hemorrhagic complications related to systemic thrombolysis, exiting in the achievement of fast patient hemodynamic stabilization and symptoms resolution, without complications. Computed tomography (CT) pulmonary angiography after 10 days from the intervention revealed the complete resolution of pulmonary artery filling defects, and the patient was discharged asymptomatic.

Conclusions

Percutaneous catheter-directed treatments represent an effective alternative therapy for PE, but further studies are needed to demonstrate safety and superiority over the actually recommended therapy.

Mechanical aspiration thrombectomy for the treatment of pulmonary embolism: A systematic review and meta-analysis

INTRODUCTION

There are no randomized trials studying the outcomes of mechanical aspiration thrombectomy (MAT) for management of pulmonary embolism (PE).

METHODS

We performed a systematic review and meta-analysis of existing literature to evaluate the safety and efficacy of MAT in the setting of PE. Inclusion criteria were as follows: studies reporting more than five patients, study involved MAT, and reported clinical outcomes and pulmonary artery pressures. Studies were excluded if they failed to separate thrombectomy data from catheter-directed thrombolysis data. Databases searched include PubMed, EMBASE, Web of Science until April, 2021.

RESULTS

Fourteen case series were identified, consisting of 516 total patients (mean age 58.4 ± 13.6 years). Three studies had only high-risk PE, two studies had only intermediate-risk PE, and the remaining nine studies had a combination of both high-risk and intermediate-risk PE. Six studies used the Inari FlowTriever device, five studies used the Indigo Aspiration system, and the remaining three studies used the Rotarex or Aspirex suction thrombectomy system. Four total studies employed thrombolytics in a patient-specific manner, with seven receiving local lysis and 17 receiving systemic lysis, and 40 receiving both. A random-effects meta-analyses of proportions of in-hospital mortality, major bleeding, technical success, and clinical success were calculated, which yielded estimate pooled percentages [95% CI] of 3.6% [0.7%, 7.9%], 0.5% [0.0%, 1.8%], 97.1% [94.8%, 98.4%], and 90.7% [85.5%, 94.3%].

CONCLUSION

There is significant heterogeneity in clinical, physiologic, and angiographic data in the currently available data on MAT. RCTs with consistent parameters and outcomes measures are still needed.

FlowTriever Retrieval System for the treatment of pulmonary embolism: overview of its safety and efficacy

INTRODUCTION

Pulmonary embolism (PE) is the third leading cause of cardiovascular mortality. There has been little change in PE mortality rates over the past two decades making this an appealing area for innovation and development.

AREAS COVERED

While anticoagulation (AC) and systemic thrombolysis (ST) are the mainstay treatments for high-risk PE and intermediate-high-risk PE with decompensation, advancements in catheter- based therapies offer potential alternatives. Areas covered here will include present guidelines for PE treatment and the landscape of catheter-directed therapies with a focus on the FlowTriever (FT) Retrieval System. Available safety and efficacy data will be reviewed. An online search via Google Scholar and PubMed with the keywords INARI Flowtriever, venous thromboembolism, and pulmonary embolism, alongside bibliographies of published articles, was undertaken as a review of the literature on the FlowTriever system for this device overview.

EXPERT OPINION

The five-year outlook on the role of catheter-directed therapies in the management of PE includes continued innovation in catheter-directed therapies and a number of high-quality trials on the horizon.

In-Hospital Mortality and Related Outcomes for Elevated Risk Acute Pulmonary Embolism Treated With Mechanical Thrombectomy Versus Routine Care

PURPOSE

To compare in-hospital mortality and other hospitalization related outcomes of elevated risk patients (Pulmonary Embolism Severity Index [PESI] score of 4 or 5, and, European Society of Cardiology [ESC] classification of intermediate-high or high risk) with acute central pulmonary embolism (PE) treated with mechanical thrombectomy (MT) using the Inari FlowTriever device versus those treated with routine care (RC).

MATERIALS AND METHODS

Retrospective data was collected of all patients with acute, central PE treated at a single institution over 2 concurrent 18-month periods. All collected patients were risk stratified using the PESI and ESC Guidelines. The comparison was made between patients with acute PE with PESI scores of 4 or 5, and, ESC classification of intermediate-high or high risk based on treatment type: MT and RC. The primary endpoint evaluated was in-hospital mortality. Secondary endpoints included intensive care unit (ICU) length of stay, total hospital length of stay, and 30-day readmission.

RESULTS

Fifty-eight patients met inclusion criteria, 28 in the MT group and 30 in the RC group. Most RC patients were treated with systemic anticoagulation alone (24 of 30). In-hospital mortality was significantly lower for the MT group than for the RC group (3.6% vs 23.3%, P < .05), as was the average ICU length of stay (2.1 ± 1.2 vs 6.1 ± 8.6 days, P < .05). Total hospital length of stay and 30-day readmission rates were similar between MT and RC groups.

CONCLUSION

Initial retrospective comparison suggests MT can improve in-hospital mortality and decrease ICU length of stay for patients with acute, central PE of elevated risk (PESI 4 or 5, and, ESC intermediate-high or high risk).

Current Endovascular Treatment Options in Acute Pulmonary Embolism

Acute pulmonary embolism (PE) is a significant cause of mortality and morbidity across the globe. Over the last few decades, there have been major therapeutic advances in acute PE management, including catheter-based therapy. However, the effectiveness of catheter-based therapy in acute PE is not supported by Level I evidence, making the use of this promising treatment rather controversial and ambiguous. In this paper, we discuss the risk stratification of acute PE and review the medical and endovascular treatment options. We also summarize and review the data supporting the use of endovascular treatment options in acute PE and describe the potential role of the PE response team.