Percutaneous rheolytic thrombectomy for large pulmonary embolism: A promising treatment option

Intracoronary microcatheter indwelling for continuous pumping of low-dose thrombolytic drugs: A new approach to reperfusion in acute myocardial infarction

Reperfusion therapy of acute myocardial infarction (AMI) refers to physical or chemical recanalization and restoration of blood flow to an occluded coronary artery, and current techniques for reperfusion therapy include intravenous thrombolysis, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The number of patients receiving emergency CABG in the real world is decreasing due to the disadvantages of CABG and the improvement in PCI procedures. Thrombolytic therapy has some disadvantages such as low recanalization rate, high risk of reocclusion and bleeding, and short time window. On the other hand, intracoronary interventional therapy may meet the requirements of "early, complete and persistent" patency of coronary arteries at different time points. However, in the emergency PCI, although thrombus aspiration via a catheter or balloon dilation is performed, residual thrombus with heavy or low TIMI (thrombolysis in myocardial infarction) myocardial perfusion grading is still observed in some patients, suggesting disordered microcirculation. Currently, the treatment of microcirculatory disturbance in emergency PCI mainly employed injection of tirofiban, adenosine, thrombolytic agent or other drugs into the local area via a microcatheter in a short time, all of which can significantly reduce the thrombus load and improve TIMI perfusion. Herein, we report that a microcatheter was indwelled in the coronary artery for continuous pumping of low-dose thrombolytic drugs as reperfusion therapy in 12 patients with acute and subacute MI.

Percutaneous Management of High-Risk Pulmonary Embolism

Acute pulmonary embolism (PE) leads to an abrupt increase in pulmonary vascular resistance and right ventricular afterload, and when significant enough, can result in hemodynamic instability. High-risk PE is a dire cardiovascular emergency and portends a poor prognosis. Traditional therapeutic options to rapidly reduce thrombus burden like systemic thrombolysis and surgical pulmonary endarterectomy have limitations, both with regards to appropriate candidates and efficacy, and have limited data demonstrating their benefit in high-risk PE. There are growing percutaneous treatment options for acute PE that include both localized thrombolysis and mechanical embolectomy. Data for such therapies with high-risk PE are currently limited. However, given the limitations, there is an opportunity to improve outcomes, with percutaneous treatments options offering new mechanisms for clot reduction with a possible improved safety profile compared with systemic thrombolysis. Additionally, mechanical circulatory support options allow for complementary treatment for patients with persistent instability, allowing for a bridge to more definitive treatment options. As more data develop, a shift toward a percutaneous approach with mechanical circulatory support may become a preferred option for the management of high-risk PE at tertiary care centers.

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.

Submassive pulmonary embolism

Pulmonary embolism (PE) is a common diagnosis in critical care. Depending on the severity of clot burden, the clinical picture ranges from nearly asymptomatic to cardiovascular collapse. The signs and symptoms of PE are nonspecific. The clinician must have a high index of suspicion to make the diagnosis. PE is risk stratified into 3 categories: low-risk, submassive, and massive. Submassive PE remains the most challenging with regard to initial and long-term management. Little consensus exists as to the appropriate tests for risk stratification and therapy. This article reviews the current literature and a suggested approach to these patients.

Management of pulmonary embolism with rheolytic thrombectomy

BACKGROUND

Catheter thrombectomy combining thrombus destruction with local thrombolysis has been used in patients with pulmonary embolism (PE) who are unstable or have significant right heart dysfunction, but have contraindications to systemic thrombolytic therapy.

OBJECTIVES

To assess the outcomes of patients who underwent pulmonary embolectomy using a commercially available thrombectomy device.

METHODS

A retrospective chart review of patients who underwent pulmonary embolectomy between March 2007 and August 2009 was performed. Patients were classified as having clinical massive or submassive PE, and moderate or severe right ventricular dysfunction. Data collected included pre- and postprocedure shock index (heart rate divided by systolic blood pressure) and mean pulmonary artery pressure.

RESULTS

Sixteen patients with a mean (± SD) age of 54.4 ± 15.8 years underwent embolectomy. Five had clinical massive PE (two in cardiogenic shock) and three of 11 submassive cases had severe right ventricular dysfunction. All were deemed to have contraindications to systemic lysis. Both shock index (1.02 ± 33 preintervention versus 0.71 ± 0.2 postintervention [P=0.001]) and mean pulmonary artery pressure (34.5 ± 9.9 mmHg preintervention versus 27.1 ± 7.1 postintervention [P=0.01]) improved. In the massive PE group, one patient died and two survivors experienced retroperitoneal bleeding and transient renal failure. At follow-up (17.3 ± 7.8 months), two patients in the massive PE group demonstrated evidence of mild cor pulmonale.

CONCLUSION

Rheolytic thrombectomy is an effective strategy in managing massive PE, particularly in patients who have well-defined contraindications to systemic lytic therapy. The effectiveness of rheolytic thrombectomy for submassive PE is not as well defined, but warrants a comparison with systemic lytic therapy.

Endovascular therapy for acute pulmonary embolism

Acute pulmonary embolism (PE) is the third most common cause of death among hospitalized patients. Treatment escalation beyond anticoagulation therapy is necessary in patients with massive PE (defined by hemodynamic shock) as well as in many patients with submassive PE (defined by right ventricular strain). The best current evidence suggests that modern catheter-directed therapy to achieve rapid central clot debulking should be considered as an early or first-line treatment option for patients with acute massive PE; and emerging evidence suggests a catheter-directed thrombolytic infusion should be considered as adjunctive therapy for many patients with acute submassive PE. This article reviews the current approach to endovascular therapy for acute PE in the context of appropriate diagnosis, risk stratification, and management of acute massive and acute submassive PE.

Fibrinolysis for acute pulmonary embolism

Acute pulmonary embolism (PE) presents as a constellation of clinical syndromes with a variety of prognostic implications. Patients with acute PE who have normal systemic arterial blood pressure and no evidence of right ventricular (RV) dysfunction have an excellent prognosis with therapeutic anticoagulation alone. Normotensive acute PE patients with evidence of RV dysfunction are categorized as having submassive PE and comprise a population at intermediate risk for adverse events and early mortality. Patients with massive PE present with syncope, systemic arterial hypotension, cardiogenic shock, or cardiac arrest and have the highest risk for short-term mortality and adverse events. The majority of deaths from acute PE are due to RV pressure overload and subsequent RV failure. The goal of fibrinolysis in acute PE is to rapidly reduce RV afterload and avert impending hemodynamic collapse and death. Although generally considered to be a life-saving intervention in massive PE, fibrinolysis remains controversial for submassive PE. Successful administration of fibrinolytic therapy requires weighing benefit versus risk. Major bleeding, in particular intracranial hemorrhage, is the most feared complication of fibrinolysis. Alternatives to fibrinolysis for acute PE, including surgical embolectomy, catheter-assisted embolectomy, and inferior vena cava (IVC) filter insertion, should be considered when contraindications exist or when patients have failed to respond to an initial trial of fibrinolytic therapy. Patients with massive and submassive PE may be best served by rapid triage to specialized centers with experience in the administration of fibrinolytic therapy and the capacity to offer alternative advanced therapies such as surgical and catheter-assisted embolectomy.

Successful percutaneous mechanical thrombectomy in a haemodynamically unstable patient with massive pulmonary embolism

Massive pulmonary embolism with haemodynamic instability has a high mortality. Traditionally these patients are treated with i.v. thrombolytic therapy. When this therapeutic approach is contraindicated, surgical embolectomy and most recently, percutaneous mechanical interventions are alternative treatment options. This case report presents a 73-year-old female with a residual hemiparesis secondary to a meningioma resection 45 days previously, who presented with progressive shortness of breath, accompanied by oppressive chest pain, hypotension, tachycardia and severe hypoxaemia. CT pulmonary angiogram confirmed a massive pulmonary embolism extending into the lobar branches bilaterally. The patient was treated with percutaneous mechanical thrombectomy with excellent haemodynamic and clinical outcomes.

Catheter-directed therapy for the treatment of massive pulmonary embolism: systematic review and meta-analysis of modern techniques

PURPOSE

Systemic thrombolysis for the treatment of acute pulmonary embolism (PE) carries an estimated 20% risk of major hemorrhage, including a 3%-5% risk of hemorrhagic stroke. The authors used evidence-based methods to evaluate the safety and effectiveness of modern catheter-directed therapy (CDT) as an alternative treatment for massive PE.

MATERIALS AND METHODS

The systematic review was initiated by electronic literature searches (MEDLINE, EMBASE) for studies published from January 1990 through September 2008. Inclusion criteria were applied to select patients with acute massive PE treated with modern CDT. Modern techniques were defined as the use of low-profile devices (< or =10 F), mechanical fragmentation and/or aspiration of emboli including rheolytic thrombectomy, and intraclot thrombolytic injection if a local drug was infused. Relevant non-English language articles were translated into English. Paired reviewers assessed study quality and abstracted data. Meta-analysis was performed by using random effects models to calculate pooled estimates for complications and clinical success rates across studies. Clinical success was defined as stabilization of hemodynamics, resolution of hypoxia, and survival to hospital discharge.

RESULTS

Five hundred ninety-four patients from 35 studies (six prospective, 29 retrospective) met the criteria for inclusion. The pooled clinical success rate from CDT was 86.5% (95% confidence interval [CI]: 82.1%, 90.2%). Pooled risks of minor and major procedural complications were 7.9% (95% CI: 5.0%, 11.3%) and 2.4% (95% CI: 1.9%, 4.3%), respectively. Data on the use of systemic thrombolysis before CDT were available in 571 patients; 546 of those patients (95%) were treated with CDT as the first adjunct to heparin without previous intravenous thrombolysis.

CONCLUSIONS

Modern CDT is a relatively safe and effective treatment for acute massive PE. At experienced centers, CDT should be considered as a first-line treatment for patients with massive PE.

Treatment of massive pulmonary embolism utilizing a multidisciplinary approach: a case study

Massive pulmonary embolism (PE) is associated, historically, with a high mortality rate.Treatment options include systemic anticoagulation, catheter-directed thrombolytic therapy, surgical embolectomy, fragmentation techniques, and catheter embolectomy. Extracorporeal membrane oxygenation (ECMO) repeatedly has demonstrated effectiveness in providing cardiopulmonary support for the patient with a massive PE too unstable to undergo thrombolysis or embolectomy. The present case study describes a morbidly obese patient, status post gastric bypass surgery, who presented with PE, and acute respiratory and cardiac failure. A description of the patient’s management plan, which includes a simple, rapidly deployed ECMO system (Levitronix® CentriMag® and Jostra Quadrox D), systemic- and catheter-directed thrombolytic therapy and rheolytic thrombectomy (AngioJet® Series 3000, Possis Medical, Minneapolis, MN).

Rheolytic thrombectomy in patients with massive and submassive acute pulmonary embolism

OBJECTIVES

To appraise the impact of AngioJet rheolytic thrombectomy (RT) on angiographic and clinical endpoints in patients with acute pulmonary embolism (PE).

BACKGROUND

The management of patients with acute PE and hemodynamic compromise, based mainly on anticoagulant and thrombolytic therapies, is challenging and still suboptimal in many patients. In such a setting, mechanical removal of thrombus from pulmonary circulation holds the promise of significant clinical benefits, albeit remains under debate.

METHODS

We retrospectively report on 51 patients referred to our catheterization laboratory and treated with AngioJet RT. Patients were classified according to the degree of hemodynamic compromise (shock, hypotension, and right ventricular dysfunction) to explore thoroughly the degree of angiographic pulmonary involvement (angiographic massive PE was defined as the presence of a Miller index >or= 17) and the impact on angiographic (obstruction, perfusion, and Miller indexes) and clinical (all-cause death, recurrence of PE, bleeding, renal failure, and severe thrombocytopenia) endpoints of AngioJet RT.

RESULTS

Angiographic massive PE was present in all patients with shock, whereas patients with right ventricular dysfunction and hypotension showed a similar substantial pulmonary vascular bed involvement. Technical success was obtained in 92.2% of patients, with a significant improvement in obstruction, perfusion and Miller indexes in each subgroup (all P < 0.0001). Four patients reported major bleedings and eight (15.7%) died in-hospital. Laboratory experience was significantly associated to a lower rate of major bleedings. All survivors were alive at long-term follow-up (35.5 +/- 21.7 months) except three who expired due to cancer and acute myocardial infarction.

CONCLUSIONS

In experienced hands AngioJet RT can be operated safely and effectively in most patients with acute PE, either massive or submassive, and substantial involvement of pulmonary vascular bed.

Mechanical and Enzymatic Thrombolysis of Acute Pulmonary Embolus: Review of the Literature and Cases from Our Institution

Pulmonary embolism (PE) is a major cause of morbidity and mortality in the United States. Patients with massive PE have a high mortality rate, with two of every three deaths occurring in the first hour. The mainstay of treatment for PE is anticoagulation. However, when the patient is in extremis, intravenous lysis of the clot is indicated. Recently, mechanical fragmentation with or without pharmacologic thrombolysis has been shown to have a role in therapy for patients with massive PE, as well as in those patients who have a contraindication to anticoagulation. We discuss our experience with mechanical fragmentation in the treatment of PE and review the literature.

Early and long-term clinical results of AngioJet rheolytic thrombectomy in patients with acute pulmonary embolism

Anticoagulant and thrombolytic therapies are a mainstay in the management of acute pulmonary embolism (PE), especially when hemodynamic compromise is present. However, systemic drugs cannot achieve timely and effective treatment of acute PE in all patients. In such a setting, mechanical removal of thrombus from the pulmonary circulation holds the promise of significant clinical benefits, although it remains untested. We report early and long-term outcome of patients with massive or submassive acute PE treated with rheolytic thrombectomy by means of the 6Fr Xpeedior AngioJet device at our institution. Three main groups were defined pre hoc: subjects with severe (i.e., shock), moderate, or mild hemodynamic compromise. Technical and procedural successes, obstruction, perfusion and Miller indexes, and clinical events were appraised. In total 25 patients were treated with thrombectomy (8 in severe, 12 in moderate, and 5 in mild hemodynamic compromise). Technical and procedural successes were obtained in all patients, as confirmed by the significant improvement in obstruction, perfusion and Miller indexes overall, and in each subgroup (all p values <0.001). Improvement in obstruction, perfusion, and Miller indexes at the end of the procedure could also be confirmed in patients (n = 8) treated with local fibrinolysis and in the absence of concomitant thrombolysis (n = 17, p <0.05). Four patients died in hospital, all other patients but 1 were safely discharged after an appropriate hospital stay, and all were alive at long-term follow-up (median 61 months). In conclusion, this study supports at early and long-term follow-up the effectiveness and safety of rheolytic thrombectomy for PE.