The following is a summary ofOptimal reperfusion strategy in acute high-risk pulmonary embolism requiring extracorporeal membrane oxygenation support: a systematic review and meta-analysis” published in the November 2022 issue of Respiratory by Chopard et al.

When a patient has a high-risk pulmonary embolism (PE) and needs extracorporeal membrane oxygenation (ECMO) implantation, the best approach of revascularizing the lungs is debatable. researchers compared the mortality and bleeding outcomes of patients treated with mechanical embolectomy to those treated with other techniques, such as systemic thrombolysis, catheter-directed thrombolysis, or ECMO as monotherapy.

There were 835 studies found, but only 17 were included, with a total of 327 individuals with PE. Mechanical pulmonary reperfusion was used to treat 32.4% of patients (among whom 85.9% underwent surgical embolectomy), whereas other techniques were used to treat 67.6%. Comparing the mortality rates of the mechanical reperfusion group and the “other techniques” group, investigators find that the former had a rate of 22.6% and the latter 42.8%. When compared to alternative reperfusion techniques, the pooled odds ratio for mortality with mechanical reperfusion was 0.439 (95% CI 0.237-0.816) (P=0.009; I2 =35.2%), and when compared to thrombolysis, the odds ratio for surgical embolectomy was 0.368 (95% CI 0.185-0.733) (P=0.004; I2=32.9%). When comparing the 2 groups of ECMO patients, those receiving mechanical reperfusion had a higher incidence of bleeding (22.2%) than those receiving “other techniques” (19.1%) (OR 1.27, 95% CI 0.54-2.96; I2=7.7%). 

In the meta-regression model, the covariates “more than one pulmonary reperfusion therapy,” “ECMO implantation before pulmonary reperfusion,” “clinical presentation of PE,” and “cancer-associated PE” were not shown to have any correlation with the outcomes of interest. The current meta-analysis and meta-regression results suggest that mechanical reperfusion, particularly by surgical embolectomy, may yield favorable results regardless of the timing of ECMO implantation in the reperfusion timeline, independent of the administration of thrombolysis or the presentation of cardiac arrest.