doi: 10.1161/01.CIR.0000012526.21603.25
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(Circulation. 2002;105:1416.)
© 2002 American Heart Association, Inc.
Acute Pulmonary Embolectomy
A Contemporary Approach
From the Departments of Surgery (L.A., J.G.B.) and Medicine (C.S.W., S.Z.G.), Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass.
Corresponding to Samuel Z. Goldhaber, MD, Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115. E-mail sgoldhaber{at}partners.org
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Abstract |
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Background— Acute pulmonary embolism confers a high mortality rate despite advances in diagnosis and therapy. Thrombolysis is often effective but has a high frequency of major bleeding complications, especially intracranial hemorrhage. Therefore, we liberalized our criteria for acute pulmonary embolectomy and considered operating on patients with anatomically extensive pulmonary embolism and concomitant moderate to severe right ventricular dysfunction despite preserved systemic arterial pressure.
Methods and Results— We report 29 (17 men and 12 women) consecutive patients who underwent embolectomy from October 1999 through October 2001. Twenty-six patients (89%) survived surgery and were alive more than 1 month postoperatively. Median follow-up is 10 months.
Conclusion— The high survival rate of 89% can be attributed to improved surgical technique, rapid diagnosis and triage, and careful patient selection. We hope that other tertiary centers will evaluate pulmonary embolism patients with an algorithm that includes surgical embolectomy as one of several therapeutic options. Our contemporary approach to pulmonary embolectomy no longer confines this operation to a treatment of last resort reserved for clinically desperate circumstances.
Key Words: embolism • surgery • thrombolysis • thrombosis • thrombus
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Introduction |
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Acute pulmonary embolism (PE) continues to have a high mortality rate despite advances in diagnosis and therapy. In the International Cooperative PE Registry of 2454 consecutively enrolled patients, 17.4% died within 90 days of follow-up. This Registry also demonstrated a surprisingly high intracranial hemorrhage rate of 3.0% among PE patients treated with thrombolytic therapy.1 A high frequency of major bleeding complications with thrombolysis was also reported in 2 smaller contemporary PE registries.2,3 These disturbing observations prompted us to consider alternatives to thrombolysis among patients at high risk for adverse outcomes if treated only with anticoagulation and insertion of an inferior vena caval filter.4
Prior to October 1999, we had performed 1 to 3 embolectomies per year at Brigham and Women’s Hospital. The usual indication was cardiogenic shock despite pressors and maximal anticoagulation. We subsequently reevaluated our practice and liberalized our indications. We began considering for embolectomy patients with anatomically extensive PE and moderate to severe right ventricular dysfunction despite preserved hemodynamics.
We now report a series of 29 patients who underwent embolectomy from October 1999 through October 2001. We describe demographics, risk factors, indications for surgery, and outcomes, including survival in 26 of 29 patients.
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Methods |
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After full median sternotomy and pericardiotomy, patients were heparinized and cannulated for cardiopulmonary bypass. The procedure was performed under normothermia without cardioplegic arrest. Through a transverse arteriotomy in the main pulmonary artery, the clot was gently extracted, en bloc if possible, under direct vision using simple gallbladder stone forceps. Vacuum-assisted venous drainage permitted rapid right atrial exploration if indicated by transesophageal echocardiography. In most patients, an inferior vena caval filter was inserted directly through the right atrial pursestring prior to sternal closure. Residual right ventricular stunning was common and, as a result, inotropic support was frequently necessary to wean from cardiopulmonary bypass.5
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Results |
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During a 25-month period, 29 patients (17 men and 12 women) underwent emergency embolectomy to treat acute PE (Table). All but 5 had perioperative placement of an inferior vena caval filter. Eleven of the 29 underwent concomitant cardiac surgical procedures: 3 had repair of a patent foramen ovale after paradoxical embolism, 7 had excision of right atrial thrombi identified preoperatively, and 1 had resection of a left atrial myxoma. The average age (±SD) was 61±15 years (median 61, range 34 to 86 years).
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The preoperative diagnosis of PE was established by lung scan or chest computed tomography (CT) scan; only 5 patients underwent conventional contrast pulmonary angiography. One patient who presented with cardiac arrest was taken directly to the Operating Room without preoperative imaging. All patients had large central emboli in the right and/or left pulmonary artery and many presented with a true saddle embolism. All 26 patients who underwent preoperative echocardiography had moderate or severe right ventricular dysfunction.
In the 18 patients who did not require concomitant cardiac surgical procedures, nonsurgical management strategies were initially considered. Two patients developed progressive systemic hypotension and hypoxemia despite administration of alteplase. Of the remaining 16 patients, 12 had contraindications to thrombolysis including: 6 with recent surgery, 3 with recent stroke, 1 with a lung mass presumed to be cancerous, 1 with a brain tumor, and 1 with a cavernous hemangioma. Four patients underwent embolectomy without contraindications to thrombolysis. One of these 4 patients was profoundly hypotensive and was receiving high-dose dopamine preoperatively. Seventeen patients (59%) underwent embolectomy as weekend emergency cases, equally distributed with 6 on Friday evening, 6 on Saturday, and 5 on Sunday.
Twenty-six patients (89%) survived surgery and were alive more than 1 month postoperatively. Median long-term follow-up is 10 months. One late death occurred 5 months postoperatively due to newly diagnosed hepatocellular carcinoma. The 4th patient in our series, a 50-year-old man, died of intractable right ventricular failure after recurrent PE postoperatively. We had not initially placed an inferior vena caval filter in this patient. Reoperative embolectomy with filter placement was not successful. The 14th patient, a 34-year-old man who had undergone knee arthroscopy, was in full cardiac arrest on arrival. Although he recovered hemodynamically, he did not regain consciousness and was declared brain dead on the second postoperative day. The 27th patient, an 84-year-old woman, had failed thrombolysis and presented for embolectomy with worsening hypoxia. She suffered an extensive aortic dissection during cannulation for cardiopulmonary bypass. Although this was repaired, she could not be weaned from bypass as a result of intractable bleeding. The 21st patient suffered cardiac tamponade within hours of surgery. This complication was successfully managed by reopening his sternal incision in the Cardiac Surgical Intensive Care Unit and draining the hemorrhagic fluid that had accumulated in his mediastinum.
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Discussion |
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We report the largest single-center contemporary experience with emergency pulmonary embolectomy in a 2-year period. The high survival rate of 89% is, in our opinion, attributable to specific aspects of the surgical technique, rapid diagnosis and treatment, and careful patient selection.
We have incorporated lessons derived from the postoperative courses of the 3 patients who did not survive. First, we now routinely place vena caval filters perioperatively to prevent recurrent PE. Second, we now recognize that no patient with out-of-hospital cardiac arrest has ever survived emergency embolectomy if a spontaneous heart rate could not be restored preoperatively. Third, we will not consider octogenarians as suitable candidates for embolectomy if they have relative contraindications (such as failed thrombolysis) to surgery in addition to age.
Widespread availability of chest CT scanning facilitated rapid noninvasive detection of central PE amenable to embolectomy in many of our patients,6 thus avoiding potential complications and the hypotensive effects of conventional contrast pulmonary angiography. Rapid transport to the operating room despite apparent hemodynamic stability was a cornerstone of our management strategy. Therefore, out-of-hospital patients were usually transferred by helicopter rather than by ground ambulance.
Our success hinged on having established a multidisciplinary evaluation team with a widespread reputation for 24-hour availability, 7 days per week. Indeed, more than half underwent surgery during the weekend, a time notorious for increased in-hospital mortality from many diseases, including PE.7
Careful patient selection was also important. On average, our patients were not as critically ill as those reported in previous series where the operative mortality has averaged 30%.5 In particular, only 1 of our patients had suffered a preoperative cardiac arrest, the strongest predictor of operative mortality. We recognized that right ventricular hypokinesis and dilatation are associated with an increased rate of mortality and recurrent PE.8 Consequently, we decided to operate on most patients in our series when they demonstrated impending hemodynamic instability with moderate or severe right ventricular dysfunction despite preserved systemic arterial pressure.9
Specific aspects of the surgical technique minimized perioperative morbidity and mortality. The procedure was performed without aortic cross-clamping, cardioplegic, or fibrillatory arrest on a warm, beating heart. Avoiding ischemic injury to the stunned right ventricle decreases postoperative right heart dysfunction. Keeping the heart unloaded and well-perfused during the embolectomy aids the resuscitation of the stunned right ventricle, most likely by regenerating depleted energy stores. Another key component of our surgical approach is the complete avoidance of blind instrumentation of the fragile pulmonary arteries. Such maneuvers can be traumatic and may lead to fatal pulmonary hemorrhage. Instead, we limited extraction to directly visible clot, which we were always able to extract from segmental arteries.
Four of the patients could have undergone thrombolysis rather than embolectomy. These patients would have been suitable for enrollment in a clinical trial comparing the efficacy and safety of these 2 approaches. A previous nonrandomized comparison examined outcomes in 37 patients of whom 24 received thrombolysis and 13 underwent embolectomy.10 The survival rate was 67% in the thrombolysis group compared with 77% in the embolectomy group. Those receiving thrombolysis had a higher rate of major hemorrhage and recurrent PE than those undergoing embolectomy.
The precise indications for embolectomy will probably never be based on a randomized clinical trial. Clinical trials for management of critically ill PE patients have been dauntingly difficult to organize. Even the indications for PE thrombolysis have not been well established, and a large-scale definitive clinical trial to study thrombolysis is long overdue.11 Furthermore, the optimal role for catheter embolectomy remains uncertain.12
Several factors may lead one to question the degree to which our results can be generalized to other centers. The current series is observational, not randomized. Medical evaluation was spearheaded by a single cardiologist (S.Z.G.), and only 2 surgeons (L.A. and J.B.) with a special interest in embolectomy performed all of the procedures.
Nonetheless, we hope that our encouraging results will stimulate other tertiary centers to organize similar programs for evaluation of PE patients with an algorithm that includes surgical embolectomy as one of several available treatment modalities and not merely as a treatment of last resort to be reserved for desperate situations. A critical mass of severely ill PE patients and devoted personnel with adequate resources are fundamental requirements for a successful effort in surgical embolectomy.
Received December 20, 2001; revision received January 28, 2002; accepted January 28, 2002.
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References |
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TopAbstractIntroductionMethodsResultsDiscussionReferences |
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1. Goldhaber SZ, Visani L, De Rosa M. Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER). Lancet. 1999; 353: 1386–1389.[CrossRef][Medline] [Order article via Infotrieve]
2. Meyer G, Gisselbrecht M, Diehl JL, et al. Incidence and predictors of major hemorrhagic complications from thrombolytic therapy in patients with massive pulmonary embolism. Am J Med. 1998; 105: 472–477.[CrossRef][Medline] [Order article via Infotrieve]
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Hamel E, Pacouret G, Vincentelli D, et al. Thrombolysis or heparin therapy in massive pulmonary embolism with right ventricular dilation: results from a 128-patient monocenter registry. Chest. 2001; 120: 120–125.
4. Goldhaber SZ. Thrombolysis in pulmonary embolism: a debatable indication. Thromb Haemost. 2001; 86: 444–451.[Medline] [Order article via Infotrieve]
5. Aklog L. Emergency surgical pulmonary embolectomy. Semin Vasc Med. 2001; 1: 235–246.[CrossRef][Medline] [Order article via Infotrieve]
6. Costello P, Gupta KB. Pulmonary embolism: imaging modalities—V/Q scan, spiral (helical) CT, and MRI. Semin Vasc Med. 2001; 1: 155–163.[CrossRef][Medline] [Order article via Infotrieve]
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Bell CM, Redelmeier DA. Mortality among patients admitted to hospitals on weekends as compared with weekdays. N Engl J Med. 2001; 345: 663–668.
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Grifoni S, Olivotto I, Cecchini P, et al. Short-term clinical outcome of patients with acute pulmonary embolism, normal blood pressure, and echocardiographic right ventricular dysfunction. Circulation. 2000; 101: 2817–2822.
9. Cannon CP, Goldhaber SZ. Cardiovascular risk stratification of pulmonary embolism. Am J Cardiol. 1996; 78: 1149–1151.[Medline] [Order article via Infotrieve]
10. Gulba DC, Schmid C, Borst HG, et al. Medical compared with surgical treatment for massive pulmonary embolism. Lancet. 1994; 343: 576–577.[CrossRef][Medline] [Order article via Infotrieve]
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Goldhaber SZ. Thrombolysis in pulmonary embolism: a large-scale trial is overdue. Circulation. 2001; 104: 2876–2878.
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Goldhaber SZ. Integration of catheter thrombectomy into our armamentarium to treat acute pulmonary embolism. Chest. 1998; 114: 1237–1238.
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