Rationale for catheter directed therapy in pulmonary embolism

Catheter-directed thrombolysis compared with systemic thrombolysis and anticoagulation in patients with intermediate- or high-risk pulmonary embolism: systematic review and network meta-analysis

BACKGROUND

Therapeutic options for intermediate- or high-risk pulmonary embolism (PE) include anticoagulation, systemic thrombolysis and catheter-directed thrombolysis (CDT); however, the role of CDT remains controversial. We sought to compare the efficacy and safety of CDT with other therapeutic options using network meta-analysis.

METHODS

We searched PubMed (MEDLINE), Embase, ClinicalTrials.gov and Cochrane Library from inception to Oct. 18, 2022. We included randomized controlled trials and observational studies that compared therapeutic options for PE, including anticoagulation, systemic thrombolysis and CDT among patients with intermediate- or high-risk PE. The efficacy outcome was in-hospital death. Safety outcomes included major bleeding, intracerebral hemorrhage and minor bleeding.

RESULTS

We included data from 44 studies, representing 20 006 patients. Compared with systemic thrombolysis, CDT was associated with a decreased risk of death (odd ratio [OR] 0.43, 95% confidence interval [CI] 0.32-0.57), intracerebral hemorrhage (OR 0.44, 95% CI 0.29-0.64), major bleeding (OR 0.61, 95% CI 0.53-0.70) and blood transfusion (OR 0.46, 95% CI 0.28-0.77). However, no difference in minor bleeding was observed between the 2 therapeutic options (OR 1.11, 95% CI 0.66-1.87). Compared with anticoagulation, CDT was also associated with decreased risk of death (OR 0.36, 95% CI 0.25-0.52), with no increased risk of intracerebral hemorrhage (OR 1.33, 95% CI 0.63-2.79) or major bleeding (OR 1.24, 95% CI 0.88-1.75).

INTERPRETATION

With moderate certainty of evidence, the risk of death and major bleeding complications was lower with CDT than with systemic thrombolysis. Compared with anticoagulation, CDT was associated with a probable lower risk of death and a similar risk of intracerebral hemorrhage, with moderate certainty of evidence. Although these findings are largely based on observational data, CDT may be considered as a first-line therapy in patients with intermediate- or high-risk PE.

PROTOCOL REGISTRATION

PROSPERO - CRD42020182163.

How we dealt with the double whammy! Acute pulmonary embolism with abdominal aortic clot and renal infarcts

Pulmonary embolism (PE) is the third most common cause of cardiovascular mortality in the United States, and the submassive PE accounts for 20%-25% of all acute PE. In the last decade, endovascular therapy with catheter-directed thrombolysis (CDT) intervention has shown great success in the treatment of submassive PE. There is limited data regarding using these devices to treat patients with concomitant abdominal aortic and renal vessel clots. Herein, we present a case of a 23-year-old male who presented with submassive PE associated with abdominal aortic thrombosis and renal infarcts. The patient was successfully treated with CDT with complete resolution of pulmonary and bilateral renal artery clots.

Advances in Percutaneous Management of Pulmonary Embolism

Acute pulmonary embolism (PE) is a leading cause of morbidity and mortality worldwide. Systemic anticoagulation remains the recommended treatment for low-risk PE. Systemic thrombolysis is the recommended treatment for PE with hemodynamic compromise (massive/high-risk PE). A significant number of patients are not candidates for systemic thrombolysis due to the bleeding risk associated with thrombolytics. Historically, surgical pulmonary embolectomy (SPE) was recommended for massive PE with hemodynamic compromise for these patients. In the last decade, catheter-directed thrombolysis (CDT) has largely replaced SPE in the patient population with intermediate risk PE (submassive), defined as right heart strain (as evidenced by right ventricle enlargement on echocardiogram and/or computed tomography, usually along with elevation of troponin or B-type natriuretic peptide). Use of CDT increased in the last few years due to high incidence of PE in hospitalized patients with coronavirus disease 2019 pneumonia, and the use of mechanical thrombectomy (initially reserved for those with contraindications to thrombolysis) has also grown. In this article, we discuss the value of the PE response team, our approach to management of submassive (intermediate risk) and massive (high risk) PE with systemic thrombolytics, CDT, mechanical thrombectomy, and surgical embolectomy.

EkoSonic™ Endovascular System-Directed Thrombolysis in a Patient With COVID-19 Infection Presenting With Bilateral Large Pulmonary Embolism Causing Right Ventricular Strain: A Case Report

We discuss a case of a 31-year-old male patient who presented to the accident and emergency department with shortness of breath and chest pain since the morning of the day of presentation. His polymerase chain reaction (PCR) test had returned positive for severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), which causes coronavirus disease 2019 (COVID-19), two weeks ago and his main symptoms had been shortness of breath, dry cough, generalized body pain, and fever. He was not vaccinated against the COVID-19 virus. He had not required hospitalization for COVID-19 and his symptoms had improved on day 10 from the date of diagnosis; however, he developed pleuritic chest pain with shortness of breath on the day of presentation. He was found to have tachypnoea, hypoxia, and tachycardia on assessment. His electrocardiogram showed a right bundle branch block with sinus tachycardia. He underwent a CT pulmonary angiography (CTPA) that showed bilateral large pulmonary emboli extending from the main pulmonary arteries bilaterally extending to the sub-segmental level. There was evidence of right heart strain on the scan. He also had a bedside echocardiogram performed after the CT scan, which showed an enlarged right ventricle but no left ventricular thrombus.

His blood results showed D-dimer levels of 14,000 ng/mL and troponin T of 255 ng/L. He received treatment with low molecular weight heparin (LMWH) and underwent emergency EkoSonic™ Endovascular System (EKOS) thrombolysis (Boston Scientific, Marlborough, MA). He remained on ultrasound-accelerated thrombolysis (USAT) for the next 12 hours and showed significant improvement and was taken off oxygen post-EKOS thrombolysis. He was discharged home on oral rivaroxaban after 48 hours of hospital stay; follow-up after two months showed normal-sized right ventricle with no evidence of pulmonary hypertension.

Peripheral Arteriovenous Malformations: Imaging and Endovascular Management Strategies

The peripheral high-flow vascular malformation (HFVM) comprises arteriovenous malformation (AVM) and fistula (AVF), shows varied clinical presentation (ranging from subtle skin lesion to life-threatening congestive heart failure), and frequently poses diagnostic and therapeutic challenges. Importance of assigning a specific diagnosis to the vascular malformation cannot be overstated, as the treatment strategy is based on the type of vascular anomaly. Although the International Society for the Study of Vascular Anomalies (ISSVA) classification system is the most commonly accepted system for classifying congenital vascular anomalies in clinical practice, the Cho–Do et al classification is of utmost help in guiding optimal mode of treatment in peripheral AVM. Although transarterial approach remains the most commonly employed route for peripheral AVM embolization, the role of transvenous and direct percutaneous approach is ever increasing and the final decision on the approach depends on angioarchitecture of the AVM. In this article, we review various commonly employed classification systems for congenital vascular anomalies, and describe clinical features, imaging and treatment strategies for peripheral arteriovenous malformation (PAVM).

Management of Acute Pulmonary Embolism in a Patient with Sickle Cell Anemia Using Catheter-Directed Thrombolysis

The efficacy of thrombolytic therapy in submassive pulmonary embolism (PE) management is lacking, particularly in specific patient subgroups. The current case report demonstrates the use of catheter-directed thrombolysis (CDT) therapy in conjunction with standard systemic anticoagulation in a patient with sickle cell disease presenting with a submassive PE and chronic thrombus burden. CDT may potentially play a role in the management of submassive PE in sickle cell patients.

Catheter-Directed Thrombectomy for Pulmonary Embolism in the Setting of Acute Stroke

A 79-year-old male presented with an acute stroke and was treated with tissue plasminogen activator (tPA). His neurological symptoms improved, but he subsequently developed hemodynamic instability requiring intubation and vasopressors. Imaging studies revealed a massive pulmonary embolism as the cause of his worsening clinical picture. Mechanical thrombectomy using traditional devices was deemed too risky as the patient could not safely tolerate the usual anticoagulation dosage these devices require. The Penumbra Indigo® system (Alameda, CA, USA) was thus chosen for its ability to achieve thrombus aspiration within a lower therapeutic heparin range. Pulmonary artery aspiration thrombectomy was done using the device, and three days after the procedure, he was extubated and weaned completely off vasopressors. The therapy’s efficacy despite the patient’s unique life-threatening conditions demonstrates a novel application of the state-of-the-art pulmonary embolism treatment currently in research.

The Role of EkoSonic Endovascular System or EKOS® in Pulmonary Embolism

Pulmonary embolism has become a cause of great concern to health care professionals. Despite strides in research and availability of sensitive diagnostic tests, the mortality and morbidity related to this entity continues to cause tremendous economic burden. Patients present with an array of symptoms ranging from mild dyspnea to hemodynamic instability and even death. Prompt recognition of symptoms along with early risk stratification can be lifesaving. Management focuses on achieving hemodynamic stability and reducing clot burden. Approved treatment modalities include anticoagulation, systemic or catheter directed thrombolytic therapy and surgical embolectomy. In this article we will review catheter-directed thrombolytic therapy, specifically the EKOS® or the EkoSonic endovascular system. EKOS® uses ultrasound-facilitated catheter-directed thrombolysis. The rationale behind this therapy is using shorter infusion times and lower dosage of the thrombolytic therapy, thereby reducing the complications associated with their use.

Outcome Measures for Acute Submassive Pulmonary Embolisms at a Community-Based Hospital Using Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis

PURPOSE

Ultrasound-facilitated, catheter-directed, low-dose fibrinolysis (USAT) appears to provide promising results for the management of acute submassive pulmonary embolisms (ASMPEs) at tertiary care centers. This study assessed outcome measures at a community-based hospital systems and compared results to known studies.

MATERIALS AND METHODS

This is a single-center, retrospective study assessing clinical outcomes of the EkoSonic Endovascular System intervention for ASMPEs performed by three surgical 3 subspecialties (interventional radiology, interventional cardiology, and vascular surgery) part of a pulmonary embolism response team (PERT). We reviewed 146 PERT activations from June 2013 to December 2017. Eighty-three patients with ASMPEs underwent USAT.

RESULTS

Our study showed greater differences (P = .01) between baseline and follow-up pulmonary artery systolic pressures (20.9 ± 9.8 mm Hg [n = 14]) compared to the ULTIMA study (12.3 ± 10 mm Hg [n = 30]). Our length-of-stay measures were shorter (6.1 ± 5.1 [n = 83]; P = .0001) compared to the SEATTLE II study (8.8 ± 5.0 [n = 150]). Preprocedure transthoracic echocardiograms (TTEs) were performed for 54 (65%) of 83 patients. Postprocedure TTEs at 48 hours was performed for 52 (62%) of 83 patients. Use of TTEs before and after intervention did not change outcomes. Intracranial hemorrhage was not observed in our patient population. There was no difference in outcomes between the three subspecialties in our study.

CONCLUSIONS

Use of USAT in a community-based hospital PERT has similar outcomes to tertiary care centers. Furthermore, similar outcomes were observed between the three subspecialties suggesting development of a comprehensive care team for management of ASMPEs.

The Use of Transarterial Approaches in Peripheral Arteriovenous Malformations (AVMs)

Arteriovenous malformations (AVMs) are a subset of congenital vascular malformations (CVMs). They comprise abnormal connections between arterial and venous circulation; treatment approaches are dependent on the angioarchitecture of the AVM, specifically the number and arrangement of the feeder arteries and outflow veins. Various imaging modalities can be used to diagnose and plan treatment. Here we will review the use of transarterial approaches to treat AVMs.