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Outcomes after surgical pulmonary embolectomy for acute submassive and massive pulmonary embolism: A single-center experience

Open ArchivePublished:December 06, 2017DOI:https://doi.org/10.1016/j.jtcvs.2017.10.139

      Abstract

      Objectives

      Ideal treatment strategies for submassive and massive pulmonary embolism remain unclear. Recent reports of surgical pulmonary embolectomy have demonstrated improved outcomes, but surgical technique and postoperative outcomes continue to be refined. The aim of this study is to describe in-hospital survival and right ventricular function after surgical pulmonary embolectomy for submassive and massive pulmonary embolism with excessive predicted mortality (≥5%).

      Methods

      All patients undergoing surgical pulmonary embolectomy (2011-2015) were retrospectively reviewed. Patients with pulmonary embolism were stratified as submassive, massive without arrest, and massive with arrest. Submassive was defined as normotensive with right ventricular dysfunction. Massive was defined as prolonged hypotension due to the pulmonary embolism. Preoperative demographics, intraoperative variables, and postoperative outcomes were compared.

      Results

      A total of 55 patients were identified: 28 as submassive, 18 as massive without arrest, and 9 as massive with arrest. All patients had a right ventricle/left ventricle ratio greater than 1.0. Right ventricular dysfunction decreased from moderate preoperatively to none before discharge (P < .001). In-hospital and 1-year survival were 93% and 91%, respectively, with 100% survival in the submassive group. No patients developed renal failure requiring hemodialysis at discharge or had a postoperative stroke.

      Conclusions

      In this single institution experience, surgical pulmonary embolectomy is a safe and effective therapy to treat patients with a submassive or massive pulmonary embolism. Although survival in this study is higher than previously reported for patients treated with medical therapy alone, a prospective trial comparing surgical therapy with medical therapy is necessary to further elucidate the role of surgical pulmonary embolectomy in the treatment of pulmonary embolism.

      Key Words

      Abbreviations and Acronyms:

      AHA (American Heart Association), LV (left ventricular), PE (pulmonary embolism), PESI (Pulmonary Embolism Severity Index), RIETE (Computerized Registry of Patients with Venous Thromboembolism), RV (right ventricular), STS (Society of Thoracic Surgeons)
      Figure thumbnail fx1
      Kaplan–Meier survival curve for patients undergoing surgical pulmonary embolectomy.
      Surgical pulmonary embolectomy is a safe and effective treatment for submassive and massive PE.
      This series demonstrates that surgical pulmonary embolectomy is a safe and effective therapy for patients with a submassive or massive PE. Although survival in this study is higher than previously reported with medical therapy, a prospective trial comparing surgical with medical therapy is needed to elucidate the role of surgical pulmonary embolectomy in the treatment of PE.
      See Editorial Commentary page 1107.
      See Editorial page 1082.
      Acute pulmonary embolism (PE) is estimated to cause 100,000 to 180,000 deaths per year.
      Office of the Surgeon General (US); National Heart, Lung, and Blood Institute
      Section I: deep vein thrombosis and pulmonary embolism as major public health problems.
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      The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group
      Tissue plasminogen activator for acute ischemic stroke.
      According to the American Heart Association (AHA), recommendation for surgical pulmonary embolectomy is limited to patients with a massive PE who have a contraindication to thrombolysis.
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      Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension.
      Much of the data leading to these recommendations are based on historical surgical series in which patients were taken to the operating room in extremis. As such, mortality rates for embolectomy have been reported between 20% and 50%.
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      Still, perioperative factors, surgical timing, and operative technique continue to be refined as experience with this operation grows. Moreover, the severity of RV dysfunction before the operation and recovery postembolectomy have yet to be well defined. In this single institution cohort, we aimed to analyze in-hospital survival and RV function after surgical pulmonary embolectomy for submassive and massive PE.

      Patients and Methods

       Patients

      With Institutional Review Board approval (HP-00066712), a retrospective review of the institutional cardiac surgery database was performed for all patients who underwent surgical pulmonary embolectomy (procedure code 33910 and 33916) for acute PE from January 1, 2011, to October 31, 2015, at the University of Maryland Medical Center. A manual review of patient charts was performed to confirm the operative procedure and obtain preoperative, perioperative, and postoperative variables and outcomes. Markers of RV dysfunction (troponin and N-terminal prohormone of brain natriuretic peptide) were recorded as the highest values before surgical intervention. Preoperative vital signs (heart rate, respiratory rate, blood pressure, oxygen saturation) were recorded at presentation. PE was identified by computed tomography angiography in all cases. RV dysfunction was recorded on the basis of preoperative and postoperative (before discharge) transthoracic echocardiograms. RV dysfunction (none to severe) was delineated by an independent cardiologist, who both quantitatively and qualitatively assessed RV function to obtain an overall assessment of dysfunction.
      Patients were stratified into 3 categories: submassive PE, massive PE without arrest, and massive PE with arrest. Submassive PE was defined, per the AHA, as patients with a systolic blood pressure greater than 90 mm Hg but with echocardiographic signs of RV dysfunction or dilation, computed tomography signs of RV dilation, or laboratory findings suggesting myocardial necrosis.
      • Jaff M.R.
      • McMurtry M.S.
      • Archer S.L.
      • Cushman M.
      • Goldenberg N.
      • Goldhaber S.Z.
      • et al.
      Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension.
      Massive PE without arrest was defined as patients with a systolic blood pressure less than 90 mm Hg for at least 15 minutes or requiring inotropic support, not due to a cause other than PE, or persistent profound bradycardia (heart rate <40 beats/min with signs or symptoms of shock),
      • Jaff M.R.
      • McMurtry M.S.
      • Archer S.L.
      • Cushman M.
      • Goldenberg N.
      • Goldhaber S.Z.
      • et al.
      Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension.
      without the presence of a cardiac arrest. Massive PE with arrest was defined similarly, but included only patients with a loss of pulse requiring cardiopulmonary resuscitation.

       Indications for Operation

      Among patients who were referred for surgical pulmonary embolectomy with a diagnosis of submassive or massive PE, surgical intervention was offered if their predicted risk of 30-day mortality was greater than or equal to 5%. Predicted risk of mortality associated with PE was estimated for all patients at the time of referral for surgical treatment. There are 2 internally and externally validated risk models for mortality associated with PE: the Bova score, which is valid only for high-risk normotensive (submassive PE) patients, and the Pulmonary Embolism Severity Index (PESI) score, which applies to all patients with PE. Although the Bova score accounts for only physiologic measures, the PESI score includes patient vital signs along with patient variables such as age, sex, and comorbidities (Figure 1). Predicted mortality was based on the Bova score, PESI score, and cardiac biomarkers.
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      Patients with comorbid conditions were only denied surgical intervention when estimated survival was less than 1 year, independent of the PE.
      Figure thumbnail gr1
      Figure 1Scoring and predicted mortality based on PESI score and Bova score.
      Patients with a predicted 30-day mortality rate less than 5% were treated with medical therapy and observed. If signs or symptoms of progressive RV or cardiovascular failure manifested, patients were reevaluated for surgical pulmonary embolectomy. All patients in this series had a predicted mortality rate greater than or equal to 5% on initial presentation.
      Timing of surgery, even in situations in which previous thrombolytic therapy was given or the patient was placed on venoarterial extracorporeal membrane oxygenation, was left to the surgeon's discretion (median time from admission to operating room was 4 hours). Patients were not screened on the basis of the location of thrombus. Patients with central or distal thrombus were evaluated equally for surgical intervention.

       Operative Technique and Postoperative Management

      Before induction of anesthesia, all patients were prepped and prepared for incision, in case the patient became unstable on induction. All patients were placed on cardiopulmonary bypass with mild hypothermia via median sternotomy. Central aortic and bicaval venous cannulation was used. Separate incisions were made in the right and left main pulmonary artery. By using a combination of forceps and suction extraction, the thrombus was gently and carefully removed, in its entirety, up to the subsegmental level. Intermittent, 15- to 30-second circulatory arrest periods were initiated as necessary. The operation was routinely performed on a beating heart without placement of an aortic crossclamp.
      In cases in which the patient was placed on venoarterial extracorporeal membrane oxygenation before the operation, the existing venous cannula in the femoral vein was used as the inferior vena cava cannula and the existing arterial cannula in the femoral artery was used as the aortic cannula. A separately placed superior vena cava cannula was then added in a “Y” fashion to the venous line.
      Postoperatively, anticoagulation was restarted after the total chest tube output was less than 30 mL/h for 3 consecutive hours, initially with a partial thromboplastin time of 45 to 55 seconds for 24 hours and then to a partial thromboplastin time of 60 to 80 seconds. All patients received an inferior vena cava filter, and transthoracic echocardiogram was performed before discharge.

       Clinical Outcomes

      The primary outcomes of this study were in-hospital survival and postoperative RV dysfunction. Secondary outcomes included 30-day survival, 1-year survival, postoperative stroke, acute kidney injury as defined by the Society of Thoracic Surgeons (STS) (increase of serum creatinine to ≥4.0 mg/dL or 3× the most recent preoperative creatinine level (acute increase must be at least 0.5 mg/dL), a new requirement for dialysis postoperatively), new hemodialysis at discharge, pneumonia, prolonged intubation (>24 hours postoperatively), tracheostomy, deep sternal wound infection, and sepsis.

       Statistical Analysis

      Continuous variables are presented as median with interquartile range and were compared using the Kruskal–Wallis test. Post hoc, pairwise comparisons were performed using Dunn's test with the Bonferroni correction for multiple comparisons. Categoric variables are presented as N (%) and were compared using the Fisher exact test, with post hoc analysis using the Fisher exact test with the Bonferroni correction. Pairwise significance is indicated by paired asterisks (*) or daggers (†) within a row. For analysis and presentation purposes, the descriptive terms used by the echocardiographer were converted to numeric values according to the following rubric: none – 0, mild – 1, moderate – 2, and severe – 3. In addition to reporting the appropriate medians, paired preoperative and postoperative measurements of RV dysfunction were compared using the test of marginal homogeneity. Survival was calculated as time from surgery to death and was censored for loss to follow-up using the Kaplan–Meier method. Censoring was performed per standard practice if the last confirmed follow-up occurred before the end of the study or if patients were still alive at the end of the study. The number of patients at risk at each time point was recorded. The differences in survival curves were assessed using the log-rank test.

      Results

       Patient Demographics and Risk Factors for Pulmonary Embolism

      A total of 55 patients underwent surgical pulmonary embolectomy during the study time period: 28 (51%) were submassive, 18 (33%) were massive without arrest, and 9 (16%) were massive with arrest. Outside of an increased incidence of recent surgery in the massive without arrest cohort compared with the submassive cohort, there were no significant differences in risk factors or comorbidities among the 3 groups (Tables 1, E1, and E2).
      Table 1Patient demographics and risk factors for pulmonary embolism
      Overall (n = 55)Submassive (n = 28)Massive without arrest (n = 18)Massive with arrest (n = 9)P value
      Age (y)53 (44-64)50 (41-63)55 (46-63)57 (43-67)NS
      Male33 (60%)17 (61%)10 (55%)6 (67%)NS
      RaceNS
       African-American21 (38%)12 (43%)7 (39%)2 (22%)
       White30 (55%)14 (50%)9 (50%)7 (78%)
       Other4 (7%)2 (7%)2 (11%)0 (0%)
      Medical history
       Chronic lung disease5 (9%)2 (7%)2 (11%)1 (11%)NS
       CHF1 (2%)1 (4%)0 (0%)0 (0%)NS
       DVT44 (80%)22 (79%)14 (78%)8 (89%)NS
       Malignancy8 (15%)3 (11%)3 (17%)2 (22%)NS
       Obesity34 (62%)15 (54%)13 (72%)6 (67%)NS
       Prior PE3 (6%)0 (0%)3 (17%)0 (0%)NS
      Recent surgery (<1 mo)21 (38%)6 (21%)
      Denotes significance between 2 starred groups.
      11 (61%)
      Denotes significance between 2 starred groups.
      4 (44%).024
      Surgery type
       General surgery3 (14%)1 (17%)2 (18%)0 (0%)NS
       Neurosurgery3 (14%)0 (0%)2 (18%)1 (25%)NS
       Orthopedic10 (48%)3 (50%)4 (36%)3 (75%)NS
       Other5 (24%)2 (33%)3 (27%)0 (0%)NS
      NS, Not significant; CHF, congestive heart failure; DVT, deep vein thrombosis; PE, pulmonary embolism.
      Denotes significance between 2 starred groups.

       Predicted Mortality and Preoperative Variables

      Patients in all groups had significant RV dysfunction, evaluated by an elevated troponin, elevated N-terminal prohormone of brain natriuretic peptide, and transthoracic echocardiographic evidence of RV dysfunction (Table 2). Contraindications to thrombolysis were identified in 16% of patients (9/55). The median PESI (all 3 groups) and median Bova (submassive only) scores placed all patients in the highest mortality risk class. On the basis of PESI score, median predicted 30-day mortality range for all 3 cohorts was 10% to 25.5%. Specifically in the submassive group, the Bova score predicted a median 30-day mortality rate of 15.5% (Table 3).
      Table 2Preoperative clinical variables
      Overall (n = 55)Submassive (n = 28)Massive without arrest (n = 18)Massive with arrest (n = 9)P value
      Troponin (ng/mL)0.45 (0.20-1.01)0.39 (0.19-0.98)0.31 (0.11-1.01)0.59 (0.44-0.93)NS
      NT-proBNP (pg/mL)2990 (489-4185)2590 (489-4835)2995 (905-3503)NS
      RV dysfunctionNS
       None2 (4%)1 (4%)1 (6%)0 (0%)
       Mild5 (9%)3 (11%)1 (6%)1 (11%)
       Moderate20 (36%)14 (50%)5 (28%)1 (11%)
       Severe17 (31%)7 (25%)8 (45%)2 (22%)
      Heart rate (beats/min)120 (104-132)121 (110-130)121 (100-143)111 (92-128)NS
      SBP (mm Hg)93 (80-114)108 (98-128)79 (67-89)80 (66-90)NS
      Respiratory rate (beats/min)29 (26-34)29 (25-34)28 (26-33)32 (28-35)NS
      Fio2 (%)50 (30-100)37 (27-53)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      100 (40-100)
      Denotes significance between 2 starred groups.
      100 (100-100)
      Denotes significance between 2 daggered groups.
      .001
      VA-ECMO6 (11%)0 (0%)
      Denotes significance between 2 starred groups.
      4 (22%)2 (22%)
      Denotes significance between 2 starred groups.
      .003
      NS, Not significant; NT-proBNP, N-terminal prohormone of brain natriuretic peptide; RV, right ventricular; SBP, systolic blood pressure; Fio2, inspired oxygen fraction; VA-ECMO, venoarterial extracorporeal membrane oxygenation.
      Denotes significance between 2 starred groups.
      Denotes significance between 2 daggered groups.
      Table 3Surgical groups and predicted risk scores
      Submassive (n = 28)Massive without arrest (n = 18)Massive with arrest (n = 9)P value
      Bova score5 (4-7)
      Bova class
       I0 (0%)
       II7 (25%)
       III21 (75%)
      PESI score135 (111-159)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      181 (130-201)
      Denotes significance between 2 starred groups.
      186 (143-207)
      Denotes significance between 2 daggered groups.
      .003
      PESI classNS
       I1 (4%)0 (0%)0 (0%)
       II0 (0%)0 (0%)0 (0%)
       III4 (14%)0 (0%)0 (0%)
       IV6 (21%)2 (11%)0 (0%)
       V17 (61%)16 (89%)9 (100%)
      PESI, Pulmonary Embolism Score Index; NS, not significant.
      Denotes significance between 2 starred groups.
      Denotes significance between 2 daggered groups.

       Perioperative Variables and Outcomes

      Overall, in-hospital survival was 93% with 100% survival in patients with a submassive PE (Table 4). Kaplan–Meier survival curves for each cohort are presented in Figure 2. In the massive PE without arrest cohort, there were 2 deaths: Both patients had significant preoperative strokes, and care was withdrawn because of poor neurologic prognosis. In the massive PE with arrest cohort, there were 2 in-hospital deaths: 1 patient with a significant preoperative stroke leading to withdrawal of care and 1 patient with preoperative multisystem organ failure who developed diffuse coagulopathy postoperatively with progression of organ failure (Figure E1). In-hospital survival was equivalent to 30-day survival, and there was 98% survival from discharge to 1 year. The 1 death was an 85-year-old woman who died of complications after a stroke 4 months postdischarge.
      Table 4Operative and postoperative outcomes
      Overall (n = 55)Submassive (n = 28)Massive without arrest (n = 18)Massive with arrest (n = 9)P value
      CPB time (min)66 (53-96)64 (56-89)64 (49-90)98 (58-141)NS
      Operative time (min)183 (154-235)173 (149-223)177 (154-197)238 (183-264)NS
      Ventilator time (h)23 (9-59)15 (5-25)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      42 (24-166)
      Denotes significance between 2 starred groups.
      181 (23-298)
      Denotes significance between 2 daggered groups.
      .004
      Prolonged intubation26 (47%)7 (25%)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      12 (67%)
      Denotes significance between 2 starred groups.
      7 (88%)
      Denotes significance between 2 daggered groups.
      <.001
      Tracheostomy4 (7%)0 (0%)2 (11%)2 (22%).037
      ICU LOS (d)4 (3-7)3 (2-4)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      5 (3-8)
      Denotes significance between 2 starred groups.
      12 (9-29)
      Denotes significance between 2 daggered groups.
      .002
      Hospital LOS (d)8 (5-11)7 (5-10)
      Denotes significance between 2 starred groups.
      7 (5-9)
      Denotes significance between 2 daggered groups.
      13 (10-43)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      .026
      RV dysfunction (predischarge)NS
       None32 (59%)15 (53%)12 (67%)5 (56%)
       Mild9 (16%)5 (18%)1 (6%)3 (33%)
       Moderate1 (2%)1 (4%)0 (0%)0 (0%)
       Severe0 (0%)0 (0%)0 (0%)0 (0%)
      Acute kidney injury5 (9%)2 (7%)2 (1%)1 (11%)NS
      New dialysis0 (0%)0 (0%)0 (0%)0 (0%)-
      Pneumonia5 (9%)1 (4%)2 (11%)2 (22%)NS
      Stroke0 (0%)0 (0%)0 (0%)0 (0%)NS
      DSWI1 (2%)0 (0%)0 (0%)1 (11%)NS
      Sepsis1 (2%)1 (4%)0 (0%)0 (0%)NS
      In-hospital and 30-d survival51 (93%)28 (100%)16 (88%)7 (78%).033
      1-y survival91%100%
      Denotes significance between 2 starred groups.
      88%67%
      Denotes significance between 2 starred groups.
      .009
      Prolonged intubation: >24 hours postoperatively. CPB, Cardiopulmonary bypass; NS, not significant; ICU, intensive care unit; LOS, length of stay; RV, right ventricular; DSWI, deep sternal wound infection.
      Denotes significance between 2 starred groups.
      Denotes significance between 2 daggered groups.
      Figure thumbnail gr2
      Figure 2A, Stacked graph representing RV function preoperatively and postoperatively. B, Change in RV dysfunction after surgical pulmonary embolectomy.
      In subanalysis of the last 3 years of the study period (N = 46/55), improved survival was noted with only 1 death (2%) during the modern era. The 1 death was a 76-year-old woman who presented after multiple syncopal episodes and hypoxia leading to a preoperative stroke and withdrawal of care postoperatively.
      Overall, RV dysfunction significantly decreased postoperatively with all patients but 1 with no or mild RV dysfunction (Table 4, Figure 3) (P < .001). In the 1 patient whose RV dysfunction improved from severe preoperatively to only moderate postoperatively, significant chronic thromboembolic disease was identified at the time of the operation but was not able to be thoroughly addressed.
      Figure thumbnail gr3
      Figure 3Kaplan–Meier survival curves for submassive (dark blue), massive without arrest (light blue), and massive with arrest (red) in patients undergoing surgical pulmonary embolectomy.
      Nine percent of patients (5/55) developed acute kidney injury postoperatively. However, no patients required hemodialysis by discharge or had a new cerebrovascular accident. One patient had a deep sternal wound infection, and 1 patient developed sepsis postoperatively.

      Discussion

      In this study, we sought to analyze in-hospital survival and RV dysfunction after surgical pulmonary embolectomy for acute submassive and massive PE. We found excellent survival, near normalization of RV function, and minimal morbidity in this series. Our in-hospital survival was 93% with 100% survival in patients with submassive PE. Furthermore, there was only 1 death at midterm follow-up in this series (Video 1).
      Figure thumbnail fx2
      Video 1The study's lead author discusses the article and importance of this research. Video available at: http://www.jtcvsonline.org/article/S0022-5223(17)32768-X/fulltext.
      Currently, the AHA and American College of Chest Physicians recommend systemic thrombolysis as first-line therapy in patients with a massive PE and consideration of thrombolysis in patients with a submassive PE.
      • Jaff M.R.
      • McMurtry M.S.
      • Archer S.L.
      • Cushman M.
      • Goldenberg N.
      • Goldhaber S.Z.
      • et al.
      Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension.
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      • et al.
      Antithrombotic therapy for VTE disease: CHEST guideline and expert panel report.
      These recommendations are based, in part, on large, nonrandomized registry data, including International Cooperative Pulmonary Embolism Registry, the Computerized Registry of Patients with Venous Thromboembolism (RIETE), and Multicenter Emergency Medicine Pulmonary Embolism in the Real World Registry, which have shown a trend toward lower mortality. However, when analyzing the studies individually, none of these reports show a statistically significant difference in mortality after thrombolysis for even massive PE.
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      Massive pulmonary embolism.
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      • et al.
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      In fact, both the RIETE and the Multicenter Emergency Medicine Pulmonary Embolism in the Real World Registry suggest an increase in overall mortality in a propensity-matched analysis of patients with submassive PE.
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      • et al.
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      Furthermore, several randomized control trials, comparing anticoagulation alone with anticoagulation and fibrinolytics for patients with a submassive PE, showed no statistically significant difference in mortality.
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      • et al.
      Bolus tenecteplase for right ventricle dysfunction in hemodynamically stable patients with pulmonary embolism.
      • Kline J.A.
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      • Courtney D.M.
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      • Jones A.E.
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      • et al.
      Treatment of submassive pulmonary embolism with tenecteplase or placebo: cardiopulmonary outcomes at 3 months: multicenter double-blind, placebo-controlled randomized trial.
      This was maintained even in 2 of the 3 major meta-analyses.
      • Xu Q.
      • Huang K.
      • Zhai Z.
      • Yang Y.
      • Wang J.
      • Wang C.
      Initial thrombolysis treatment compared with anticoagulation for acute intermediate-risk pulmonary embolism: a meta-analysis.
      • Marti C.
      • John G.
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      • Combescure C.
      • Sanchez O.
      • Lankeit M.
      • et al.
      Systemic thrombolytic therapy for acute pulmonary embolism: a systematic review and meta-analysis.
      • Chen H.
      • Ren C.
      • Chen H.
      Thrombolysis versus anticoagulation for the initial treatment of moderate pulmonary embolism: a meta-analysis of randomized controlled trials.
      Moreover, fibrinolysis was associated with a rate of major hemorrhage up to 11.4%.
      • Meyer G.
      • Vicaut E.
      • Danays T.
      • Agnelli G.
      • Becattini C.
      • Beyer-Westendorf J.
      • et al.
      Fibrinolysis for patients with intermediate-risk pulmonary embolism.
      • Konstantinides S.
      • Geibel A.
      • Heusel G.
      • Heinrich F.
      • Kasper W.
      • et al.
      Heparin plus alteplase compared with heparin alone in patients with submassive pulmonary embolism.
      • Becattini C.
      • Agnelli G.
      • Salvi A.
      • Grifoni S.
      • Pancaldi L.G.
      • Enea I.
      • et al.
      Bolus tenecteplase for right ventricle dysfunction in hemodynamically stable patients with pulmonary embolism.
      • Kline J.A.
      • Nordenholz K.E.
      • Courtney D.M.
      • Kabrhel C.
      • Jones A.E.
      • Rondina M.T.
      • et al.
      Treatment of submassive pulmonary embolism with tenecteplase or placebo: cardiopulmonary outcomes at 3 months: multicenter double-blind, placebo-controlled randomized trial.
      Although this study is retrospective in nature and has no comparison group, the median estimated mortality for our submassive PE cases was 15.5%, based on the Bova score.
      • Bova C.
      • Sanchez O.
      • Prandoni P.
      • Lankeit M.
      • Konstantinides S.
      • Vanni S.
      • et al.
      Identification of intermediate-risk patients with acute symptomatic pulmonary embolism.
      • Fernandez C.
      • Bova C.
      • Sanchez O.
      • Prandoni P.
      • Lankeit M.
      • Konstantinides S.
      • et al.
      Validation of a model for identification of patients at intermediate to high risk for complications associated with acute symptomatic pulmonary embolism.
      This is consistent with a 10% to 24.5% median estimated mortality range based on the PESI scores for the submassive PE cases.
      • Aujesky D.
      • Obrosky D.S.
      • Stone R.A.
      • Auble T.E.
      • Perrier A.
      • Cornuz J.
      • et al.
      Derivation and validation of a prognostic model for pulmonary embolism.
      • Weeda E.R.
      • Kohn C.G.
      • Fermann G.J.
      • Peacock W.F.
      • Tanner C.
      • McGrath D.
      • et al.
      External validation of prognostic rules for early post-pulmonary embolism mortality: assessment of a claims-based and three clinical-based approaches.
      Although these prediction models have inherent limitations and should not serve as a direct comparator to our results, the estimated 15.5% mortality provides a reference point to gauge the safety of this surgical therapy. The 0% mortality in the submassive PE cohort supports the notion that surgical pulmonary embolectomy is a safe treatment for patients with a submassive PE.
      In the massive PE cohorts, the median estimated mortality ranged from 10% to 24.5%, based on the PESI score, and 55.1%, based on the International Cooperative Pulmonary Embolism Registry.
      • Kucher N.
      • Rossi E.
      • De Rosa M.
      • Goldhaber S.Z.
      Massive pulmonary embolism.
      In patients who require cardiopulmonary resuscitation, the Moderate Pulmonary Embolism Treated with Thrombolysis trial demonstrated a mortality rate of 64.8%.
      • Kasper W.
      • Konstantinides S.
      • Geibel A.
      • Olschewski M.
      • Heinrich F.
      • Grosser K.D.
      • et al.
      Management strategies and determinants of outcome in acute major pulmonary embolism: results of a multicenter registry.
      In the current study, the 12% mortality rate in massive PE cases without arrest and 22% mortality rate in massive PE cases with arrest suggests the safety of surgical therapy for patients with a massive PE.
      Over the past decade, catheter-directed thrombolysis with and without ultrasound therapy has gained popularity and has been proposed as a minimally invasive alternative to surgical pulmonary embolectomy.
      • Bagla S.
      • Smirniotopoulos J.B.
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      Ultrasound-accelerated catheter-directed thrombolysis for acute submassive pulmonary embolism.
      • Engelberger R.P.
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      • et al.
      Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate and high-risk pulmonary embolism.
      However, the data thus far have been limited to 1 randomized trial along with small prospective and retrospective series. The Ultrasound-Assisted Thrombolysis of Pulmonary Embolism randomized trial compared ultrasound-assisted catheter-directed thrombolysis with heparin alone in patients with a submassive PE.
      • Kucher N.
      • Boekstegers P.
      • Müller O.J.
      • Kupatt C.
      • Beyer-Westendorf J.
      • Heitzer T.
      • et al.
      Randomized, controlled trial of ultrasound-assisted catheter-directed thrombolysis for acute intermediate-risk pulmonary embolism.
      Although there were no mortalities in the catheter-based arm of the study, the mean RV/left ventricular (LV) ratio was still greater than 0.9 by 90 days. This study was followed by the SEATTLE II trial, which analyzed 149 patients who underwent ultrasound-assisted catheter-directed thrombolysis for a massive or submassive PE.
      • Piazza G.
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      • Ouriel K.
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      • Sterling K.M.
      • et al.
      A prospective, single-arm, multicenter trial of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis for acute massive and submassive pulmonary embolism: the SEATTLE II Study.
      The primary end point in this study was RV/LV ratio, which again remained considerably elevated at 48 hours postprocedure. In addition, patients received a follow-up computed tomography scan to quantify the amount of remaining pulmonary artery occlusion, which demonstrated that 70% of the original occlusion, based on the Miller Index, still remained present. Moreover, previous studies have shown other catheter-based therapies to be associated with clot fragmentation and late pulmonary hypertension.
      • Goldhaber S.Z.
      Integration of catheter thromboembolectomy into our armamentarium to treat acute pulmonary embolism.
      In contrast, in this study, only 1 patient (1.8%) remained with an RV/LV ratio greater than 0.9. In that patient, who also remained with moderate RV dysfunction, significant chronic thromboembolic disease was identified intraoperatively. However, this was early in our center's experience. We have subsequently made significant efforts to identify these patients preoperatively and address this problem. These include historical factors, such as history of venous thromboembolism or progressive development of dyspnea or exercise intolerance over months to years, along with careful review of imaging, looking specifically for an enlarged pulmonary artery to aorta ratio and webbing or moth-eaten distal pulmonary vasculature. The data in the present study support the notion that surgical pulmonary embolectomy is an effective treatment for submassive and massive PE.
      Multiple reports over the past decade, including surgical pulmonary embolectomy series by Neely and colleagues
      • Neely R.C.
      • Byrne J.G.
      • Gosey I.
      • Cohn L.H.
      • Javed Q.
      • Rawn J.D.
      • et al.
      Surgical embolectomy for acute massive and submassive pulmonary embolism in a series of 115 patients.
      and Keeling and colleagues,
      • Keeling W.B.
      • Leshnower B.G.
      • Lasajanak Y.
      • Binongo J.
      • Guyton R.A.
      • Halkos M.E.
      • et al.
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      have demonstrated outstanding outcomes for patients with a submassive and massive PE.
      • Leacche M.
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      • Azari A.
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      Similar to our series, Neely and colleagues
      • Neely R.C.
      • Byrne J.G.
      • Gosey I.
      • Cohn L.H.
      • Javed Q.
      • Rawn J.D.
      • et al.
      Surgical embolectomy for acute massive and submassive pulmonary embolism in a series of 115 patients.
      report an overall mortality rate of 7%, and Keeling and colleagues
      • Keeling W.B.
      • Leshnower B.G.
      • Lasajanak Y.
      • Binongo J.
      • Guyton R.A.
      • Halkos M.E.
      • et al.
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      report only 1 death in their series of 44 patients. We believe that the present study adds a modern cohort to the published reports and further suggests that surgical pulmonary embolectomy can be performed with low morbidity and mortality. These series over the past decade challenge the previously published data from the Nationwide Inpatient Sample, which showed an overall mortality rate of 27.2% for surgical embolectomy.
      • Kalra R.
      • Bajaj N.
      • Ather S.
      • Guichard J.
      • Lancaster W.
      • Raman F.
      • et al.
      Nationwide outcomes of surgical embolectomy for acute pulmonary embolism.
      This series is limited by the retrospective nature of the study. There is no control group to compare outcomes; therefore, mortality and morbidity can be assessed only in relation to historical data. However, our analysis does provide an estimated mortality rate for the study population based on 2 internally and externally validated prediction models. Although there was a younger median patient age in our study compared with the Bova model (53 vs 72 years), age was not found to be a predictor of outcome in the model or in our experience.
      The data in this study are the first large surgical series of pulmonary embolectomy to detail patient presentation, both by vital signs and by RV dysfunction. Furthermore, this study adds a modern cohort of patients suggesting that pulmonary embolectomy is safe and effective. Still, over the 5 years of the study, we rapidly improved our surgical timing, perioperative management, and operative procedure in these patients. Given that the majority of deaths in this study were secondary to devastating preoperative neurologic injuries, we no longer advocate to take these patients directly to the operating room for surgical pulmonary embolectomy and believe that other tools should be used in this cohort. Over the last 3 years of the study period, there has only been only 1 death in 46 patients who received surgical pulmonary embolectomy, secondary to a preoperative neurologic event. We attribute the increased success over time to a greater familiarity with the diverse presentation of these patients, better perioperative management and triage, and an improved, standardized surgical technique.

      Conclusions

      Based on the minimal morbidity and mortality, and RV recovery seen in this study, further investigation in the use of surgical pulmonary embolectomy as the definitive treatment for acute submassive and massive PE is warranted.

       Conflict of Interest Statement

      Authors have nothing to disclose with regard to commercial support.

      Supplementary Data

      Appendix

      Figure thumbnail fx3
      Figure E1Flowchart describing survival in each cohort and cause of mortalities. PE, Pulmonary embolism.
      Table E1Preoperative Pulmonary Embolism Score Index characteristics
      Overall (n = 55) (%)Submassive (n = 28) (%)Massive without arrest (n = 18) (%)Massive with arrest (n = 9) (%)P value
      Male sex33 (60)17 (61)10 (56)6 (67)NS
      History of heart failure1 (2)1 (4)0 (0)0 (0)NS
      History of chronic lung disease5 (9)2 (7)2 (11)1 (11)NS
      Saturation <90%31 (56)13 (46)13 (72)5 (56)NS
      HR ≥110 beats/min38 (69)22 (79)11 (61)5 (56)NS
      RR ≥30 beats/min30 (55)16 (57)7 (39)7 (78)NS
      Temperature <36°C13 (24)5 (18)5 (28)3 (33)NS
      Malignancy8 (15)3 (11)3 (17)2 (22)NS
      SBP <100 mm Hg37 (67)10 (36)
      Denotes significance between 2 starred groups.
      ,
      Denotes significance between 2 daggered groups.
      18 (100)
      Denotes significance between 2 starred groups.
      9 (100)
      Denotes significance between 2 daggered groups.
      <.001
      Altered mental status25 (46)8 (29)
      Denotes significance between 2 starred groups.
      12 (67)
      Denotes significance between 2 starred groups.
      5 (56).03
      NS, Not significant; HR, heart rate; RR, respiratory rate; SBP, systolic blood pressure.
      Denotes significance between 2 starred groups.
      Denotes significance between 2 daggered groups.
      Table E2Preoperative Bova characteristics for patients with submassive pulmonary embolism
      Submassive (n = 28) (%)
      SBP 90-100 mm Hg10 (36)
      Elevated cardiac troponin27 (96)
      RV dysfunction27 (96)
      Heart rate ≥110 beats/min22 (79)
      SBP, Systolic blood pressure; RV, right ventricular.

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