Percutaneous Mechanical Thrombectomy for Massive Pulmonary Embolism Using a Conservative Treatment Strategy

Extracorporeal Membrane Oxygenation—First Strategy for Acute Life-Threatening Pulmonary Embolism

Background

Both venoarterial extracorporeal membrane oxygenation (VA-ECMO) and percutaneous mechanical thrombectomy (PMT) are increasingly used to treat acute life-threatening pulmonary embolism (PE). However, there are little data regarding their effectiveness. This study aimed to present the short-term outcomes after managing nine patients with acute life-threatening massive or submassive PE by VA-ECMO with or without complemented PMT and propose a preliminary treatment algorithm.

Methods

This study was a single-center retrospective review of a prospectively maintained registry. It included nine consecutive patients with massive or submassive pulmonary embolism who underwent VA-ECMO for initial hemodynamic stabilization, with or without PMT, from August 2018 to November 2021.

Results

Mean patient age was 54.7 years. Four of nine patients (44.4%) required cardiopulmonary resuscitation before or during VA-ECMO cannulation. All cannulations (100%) were successfully performed percutaneously. Overall survival was 88.9% (8 of 9 patients). One patient died from a hemorrhagic stroke. Of the survivors, the median ECMO duration was 8 days in patients treated with ECMO alone and 4 days in those treated with EMCO and PMT. Five of nine patients (55.6%) required concomitant PMT to address persistent right heart dysfunction, with the remaining survivors (44.4%) receiving VA-ECMO and anticoagulation alone. For survivors receiving VA-ECMO plus PMT, median hospital lengths of stay were 7 and 13 days, respectively.

Conclusions

An ECMO-first strategy complemented with PMT can be performed effectively and safely for acute life-threatening massive or submassive PE. VA-ECMO is feasible for initial stabilization, serving as a bridge to therapy primarily in inoperable patients with massive PE. Further evaluation in a larger cohort of patients is warranted to assess whether VA-ECMO plus PMT may offer an alternative or complementary therapy to thrombolysis or surgical thrombectomy.

Type of Research

Single-center retrospective review of a prospectively maintained registry.

Prevalence, Trends, and Outcomes of Pulmonary Embolism Treated with Mechanical and Surgical Thrombectomy from a Nationwide Inpatient Sample

Pulmonary embolism (PE) is the third most common vascular disease in the US, a frequently underdiagnosed and potentially fatal condition where embolic material blocks one or more pulmonary arteries impairing blood flow. In this study, we aim to describe the prevalence, outcomes, and predictors of mortality of PE patients treated with mechanical (MT) and surgical thrombectomy (ST). This is a retrospective study using the Agency for Healthcare Research and Quality’s HCUP NIS data from 2010−2018. We used the ninth and tenth revisions of the International Classification of Diseases clinical modification codes (ICD-9-CM and ICD-10-CM) to identify patients admitted with a primary diagnosis of PE (ICD-10-CM codes I26.02, I26.09, I26.92, I26.93, I26.94, and I26.99; ICD-9-CM codes 415.11, 415.13, and 415.19). We extracted demographics, hospital-level, and patient-level characteristics, and defined the severity of comorbid conditions using Deyo modification of the Elixhauser Comorbidity Index. The primary outcomes of interest were the utilization trends of PE (treated with MT and ST); the secondary outcomes were mortality, discharge to facility, peri-procedural complications, and length of hospital (LOS) stay; the tertiary outcome was to identify the predictors of in-hospital mortality. From 2010−2018, there were 1,627,718 hospitalizations for PE, of which 6531 (0.39%) underwent MT and 3465 (0.21%) underwent ST. The utilization trend of MT increased from 336 (0.20%) in 2010 to 1655 (0.87%) in 2018; the utilization trend of ST was 260 (0.15%) in 2010 and 430 (0.23%) in 2018. The unadjusted in-hospital mortality for MT was 9.1% with the mean LOS being 7(±0.3) days; for ST, mortality was 13.9% with a mean LOS of 13(±0.4) days. The occurrences of periprocedural complications for MT and ST were as follows: invasive mechanical ventilation was 13.8% and 32%; cardiopulmonary bypass was 3.3% and 68.3%; pulmonary embolectomy surgery was 1.7%; and bleeding complications were 1.4% and 3.4%. Predictors associated with in-hospital mortality for MT were: increasing age (OR 1.2, 95% CI 1.0−1.3, p < 0.026), female sex (OR 1.9, 95% CI 1.2−2.8, p < 0.004), large hospitals (OR 2.2, 95% 1.4−3.5, p < 0.001), and teaching hospitals (OR 1.8, 95% CI 1.1−3.1, p < 0.023). The predictor of in-hospital mortality for ST was increasing age (OR 1.2, 95% CI 1.0−1.4, p < 0.046). The number of MT procedures performed has rapidly increased over the past decade. Further studies are warranted to determine their rise and therapeutic use.

Percutaneous mechanical thrombectomy in patients with high-risk pulmonary embolism and contraindications for thrombolytic therapy

Background High-risk pulmonary embolism is associated with a high early mortality rate. We report our experience with percutaneous mechanical thrombectomy in patients with high-risk pulmonary embolism and contraindications for thrombolytic therapy. Patients and methods This was a retrospective analysis of consecutive patients with high-risk pulmonary embolism and contraindications to thrombolytic therapy. They were treated with percutaneous mechanical thrombectomy which included thrombectomy and additional thrombus aspiration when needed. Clinical parameters and survival to discharge were measured. Results From November 2005 to September 2015 we treated 25 patients with a mean age of 62.6 ± 12.7 years, 64% were men. Mean simplified Pulmonary Embolism Severity Index was 2.9. Mean maximum lactate levels were 7.8 ± 6.6 mmol/L, vasopressors were used in 77%, and 59% needed mechanical ventilation. Mechanical treatment included thrombus fragmentation complemented with aspiration (56%) and aspiration using Aspirex®S catheter (44%). Local (5 patients; 20%) and systemic (3 patients; 12%) thrombolytics were used as a salvage therapy. We observed nonsignificant improvements in systemic blood pressure (100 ± 41 mm Hg vs 119 ± 34; p = 0.100) and heart frequency (99 ± 35 min-1 vs 87 ± 31 min-1; p = 0.326) before and after treatment, respectively. Peak systolic tricuspid pressure gradient was significantly lower after treatment (57 ± 14 mm Hg vs 31 ± 3 mm Hg; p = 0.018). Overall the procedure was technically successful in 20 patients (80%) and 17 patients (68%) survived to hospital discharge. Conclusions In patients with high-risk pulmonary embolism who cannot receive thrombolytic therapy, percutaneous mechanical thrombectomy is a promising alternative to reduce pulmonary artery pressure.

Successful percutaneous thrombectomy in an elderly patient with massive pulmonary embolism with cardiogenic shock

We report on an 80-year-old woman with cardiogenic shock due to massive pulmonary embolism who was successfully treated with percutaneous thrombectomy using a conventional angiographic guide wire and catheters combined with systemic thrombolysis. We successfully treated the patient without a ventilator or extracorporeal life support. We report that percutaneous thrombectomy can provide rapid improvement of hemodynamic instability and can be used as an effective adjuvant therapy for systemic thrombolysis in patients with massive pulmonary embolism. Percutaneous thrombectomy is a less invasive and reasonable alternative to surgical embolectomy for patients with massive pulmonary embolism with cardiogenic shock.

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.

Diagnosis and management of life-threatening pulmonary embolism

Pulmonary embolus (PE) is estimated to cause 200 000 to 300 000 deaths annually. Many deaths occur in hemodynamically unstable patients and the estimated mortality for inpatients with hemodynamic instability is between 15% and 25%. The diagnosis of PE in the critically ill is often challenging because the presentation is nonspecific. Computed tomographic pulmonary angiography appears to be the most useful study for diagnosis of PE in the critically ill. For patients with renal insufficiency and contrast allergy, the ventilation perfusion scan provides an alternative. For patients too unstable to travel, echocardiography (especially transesophageal echocardiography) is another option. A positive result on lower extremity Doppler ultrasound can also aid in the decision to treat. The choice of treatment in PE depends on the estimated risk of poor outcome. The presence of hypotension is the most significant predictor of poor outcome and defines those with massive PE. Normotensive patients with evidence of right ventricular (RV) dysfunction, as assessed by echocardiography, comprise the sub-massive category and are at intermediate risk of poor outcomes. Clinically, those with sub-massive PE are difficult to distinguish from those with low-risk PE. Cardiac troponin, brain natriuretic peptide, and computed tomographic pulmonary angiography can raise the suspicion that a patient has sub-massive PE, but the echocardiogram remains the primary means of identifying RV dysfunction. The initial therapy for patients with PE is anticoagulation. Use of vasopressors, inotropes, pulmonary artery (PA) vasodilators and mechanical ventilation can stabilize critically ill patients. The recommended definitive treatment for patients with massive PE is thrombolysis (in addition to anticoagulation). In massive PE, thrombolytics reduce the risk of recurrent PE, cause rapid improvement in hemodynamics, and probably reduce mortality compared with anticoagulation alone. For patients with a contraindication to anticoagulation and thrombolytic therapy, surgical embolectomy and catheter-based therapies are options. Thrombolytic therapy in sub-massive PE results in improved pulmonary perfusion, reduced PA pressures, and a less complicated hospital course. No survival benefit has been documented, however. If one is considering the use of thrombolytic therapy in sub-massive PE, the limited documented benefit must be weighed against the increased risk of life-threatening hemorrhage. The role of surgical embolectomy and catheter-based therapies in this population is unclear. Evidence suggests that sub-massive PE is a heterogeneous group with respect to risk. It is possible that those at highest risk may benefit from thrombolysis, but existing studies do not identify subgroups within the sub-massive category. The role of inferior vena cava (IVC) filters, catheter-based interventions, and surgical embolectomy in life-threatening PE has yet to be completely defined.

Comparison of percutaneous ultrasound-accelerated thrombolysis versus catheter-directed thrombolysis in patients with acute massive pulmonary embolism

Acute massive pulmonary embolism (PE) is a life-threatening condition that requires prompt and aggressive interventions, including anticoagulation, catheter-directed thrombolysis (CDT), mechanical thrombectomy, or surgical thromboembolectomy. The aim of this study was to evaluate the treatment outcome in patients with massive PE who were treated with either ultrasound-accelerated thrombolysis using the EkoSonic Endovascular System (EKOS) or CDT intervention. During a recent 10-year period, the clinical records of all patients with massive PE undergoing catheter-directed interventions were evaluated. Patients were divided into two treatment groups: EKOS versus CDT interventions. Comparisons were made with regard to the treatment outcome between the two groups. Twenty-five patients underwent 33 catheter-directed interventions for massive PE during the study period. Among them, EKOS or CDT was performed in 15 (45%) and 18 (55%) procedures, respectively. In the EKOS group, complete thrombus removal was achieved in 100% cases. In the CDT cohort, complete or partial thrombus removal was accomplished in 7 (50%) and 2 (14%) cases, respectively. Comparing treatment success based on thrombus removal, EKOS treatment resulted in an improved treatment outcome compared with the CDT group (p < .02). The mean time of thrombolysis in EKOS and CDT group was 17.4 +/- 5.23 and 25.3 +/- 7.35 hours, respectively (p = .03). The mortality rate in the EKOS and CDT group was 9.1% and 14.2%, respectively (not significant). Treatment-related hemorrhagic complication rates in the EKOS and CDT group were 0% and 21.4%, respectively (p = .02). A significant reduction in Miller scores was noted in both groups following catheter-based interventions. No significant difference in relative Miller score improvement was observed between groups. Ultrasound-accelerated thrombolysis using the EkoSonic system is an effective treatment modality in patients with acute massive PE. When compared with CDT, this treatment modality provides similar treatment efficacy with reduced thrombolytic infusion time and treatment-related complications.

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.