Ultrasound-Assisted Catheter-Directed Thrombolysis: A Novel and Promising Endovascular Therapeutic Modality for Intermediate-Risk Pulmonary Embolism

Unmet Needs and Future Direction for Pulmonary Embolism Interventions

Venous thromboembolism (VTE) usually develops in the deep veins of the extremities. Pulmonary embolism (PE) is a type of VTE that is most commonly (∼90%) caused by a thrombus that originates from the deep veins of the lower extremities. PE is the third most common cause of death after myocardial infarction and stroke. In this review, the authors investigate and discuss the risk stratification and definitions of the aforementioned categories of PE and further explore the management of acute PE along with the types of catheter-based treatment options and their efficacy.

Management of Massive Pulmonary Embolism

Pulmonary embolism is a potentially lethal manifestation of venous thromboembolic disease. It is one of the three main causes of cardiovascular morbidity and mortality in developed countries. Over the years, better diagnostic and risk stratification measures were implemented. A generous range of new treatment options is becoming available, particularly for management of massive pulmonary embolism. Nonetheless, clinicians often face uncertainty in clinical practice due to lack of scientific support for available treatment options. The aim of this article is to review management of massive pulmonary embolism.

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.

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

BACKGROUND

Mechanical thrombectomy plays an important role in the management of acute pulmonary embolism (PE), either when rapid clot dissolution is needed or when thrombolytics are contraindicated. We describe our clinical and technical experience with the FlowTriever mechanical thrombectomy device in patients with acute PE.

MATERIALS AND METHODS

A retrospective analysis was performed on all cases of acute PE treated with the FlowTriever device at a single tertiary care hospital system during the trial period (November 2019-January 2020). Technical and clinical results, including complications, are reported.

RESULTS

Technical success was achieved in all eight successive cases (seven cases of submassive and 1 case of massive PE). Mean pulmonary artery pressure (MPAP) improved significantly after mechanical thrombectomy (27.8 ± 6.4 mmHg preprocedure; 20.5 ± 3.8 mmHg postprocedure; 7.3 ± 5.2 mmHg decrease after the procedure; P = 0.016). Hemoglobin levels did not change significantly after mechanical thrombectomy (11.8 g/dl ± 3.4 preprocedure; 9.9 g/dl ± 2.1 postprocedure; P = 0.20). Reduction in MPAP was achieved in 88% of cases (7/8) and hypoxia improved in all the nonintubated patients (7/7). Mortality observed in one patient with a massive central PE, was not related to the procedure. No mortality or procedural complications were observed in patients with submassive PE.

CONCLUSIONS

The positive initial clinical experience and safety profile using the FlowTriever in the treatment of acute PE suggests, it has the potential to fill the unmet needs of a good mechanical thrombectomy device to treat massive and submassive high-risk PE especially when thrombolytics are contraindicated.

Perioperative Acute Pulmonary Embolism: A Concise Review with Emphasis on Multidisciplinary Approach

Perioperative acute pulmonary embolism represents a relatively rare complication; however, it could be very serious and devastating in some cases. Its diagnosis could be particularly challenging, especially in the intraoperative period. Herein, we emphasize some key concepts with the aim to perform an early and appropriate risk stratification, diagnostic and therapeutic approach in a multidisciplinary fashion, a brief overview on thromboprophylaxis, with the main objective to improve outcomes and survival in these challenging patients.

Pulmonary Embolism Response Teams: A Novel Approach for the Care of Complex Patients With Pulmonary Embolism

Pulmonary embolism represents the third most common cause of cardiovascular death in the United States. Reperfusion therapeutic strategies such as systemic thrombolysis, catheter directed therapies, surgical pulmonary embolectomy, and cardiopulmonary support devices are currently available for patients with high- and intermediate-high–risk pulmonary embolism. However, deciding on optimal therapy may be challenging. Pulmonary embolism response teams have been designed to facilitate multidisciplinary decision-making with the goal to improve quality of care for complex cases with pulmonary embolism. Herein, we discuss the current role and strategies on how to leverage the strengths from pulmonary embolism response teams, its possible worldwide adoption, and implementation to improve survival and change the paradigm in the care of a potentially deadly disease.

Ultrasound-Assisted Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism

PURPOSE

Catheter-directed thrombolysis (CDT) is a relatively new therapy for pulmonary embolism that achieves the superior clot resolution compared to systemic thrombolysis while avoiding the high bleeding risk intrinsically associated with that therapy. In order to examine the efficacy and safety of CDT, we conducted a retrospective cohort study of patients undergoing ultrasound-assisted CDT at our institution.

METHODS

The charts of 30 consecutive patients who underwent CDT as a treatment of pulmonary embolism at our institution were reviewed. Risk factors for bleeding during thrombolysis were noted. Indicators of the right heart strain on computed tomography and echocardiogram, as well as the degree of pulmonary vascular obstruction, were recorded before and after CDT. Thirty-day mortality and occurrence of bleeding events were recorded.

RESULTS

Nine (30%) patients had 3 or more minor contraindications to thrombolysis and 14 (47%) had major surgery in the month prior to CDT. Right ventricular systolic pressure and vascular obstruction decreased significantly after CDT. There was a significant decrease in the proportion of patients with right ventricular dilation or hypokinesis. Decrease in pulmonary vascular obstruction was associated with nadir of fibrinogen level. No patients experienced major or moderate bleeding attributed to CDT.

CONCLUSION

Catheter-directed thrombolysis is an effective therapy in rapidly alleviating the right heart strain that is associated with increased mortality and long-term morbidity in patients with pulmonary embolism with minimal bleeding risk. Catheter-directed thrombolysis is a safe alternative to systemic thrombolysis in patients with risk factors for bleeding such as prior surgery. Future studies should examine the safety of CDT in patients with contraindications to systemic thrombolysis.