Successful resuscitation of acute massive pulmonary embolism with extracorporeal membrane oxygenation and open embolectomy

Interventional therapies in acute pulmonary embolus-current trends and future directions

Venous thromboembolic disease presenting with acute pulmonary embolus (PE) can be treated in a variety of ways from anticoagulation as an outpatient to surgical embolectomy with many new interventional therapies being developed. Mortality in these patients can be as high as 50% and many of these treatments are also considered to be high risk. Early involvement of a multidisciplinary team and patient risk stratification can aid management decisions in these complex patients who can suddenly deteriorate.In this review, we summarise the evidence behind new and developing interventional therapies in the treatment of high and intermediate-high risk PE including catheter-directed thrombolysis, pharmacomechanical thrombolysis, thromboaspiration and the growing role of extracorporeal membrane oxygenation in the stabilisation and management of this cohort of patients.

Successful thrombolysis with low dose thrombolytic agent in a patient with acute life-threatening massive pulmonary thromboembolism: A case report

Introduction

and importance: Acute massive pulmonary thromboembolism is a potentially life-threatening condition requiring urgent management to decrease mortality. Although the standard dose of systemic thrombolysis with alteplase is 100 mg, half the dose of alteplase can be used to break up clots successfully, especially if bleeding is a concern.

Case presentation

We report a case of massive pulmonary thromboembolism presenting with cardiopulmonary arrest, successfully managed with advanced cardiac life support, anticoagulants, and low-dose thrombolytics.

Clinical discussion

Management of massive pulmonary thromboembolism includes medical thrombolysis along with maintenance of hemodynamic stability. Our patient was successfully managed with low-dose thrombolytics and was continued with standard oral anticoagulants for 6 months.

Conclusion

In patients of acute massive pulmonary thromboembolism, a low dose of the thrombolytic agent can achieve complete resolution of the thrombus with less bleeding risk.

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Acute massive pulmonary thromboembolism is a life-threatening condition requiring urgent diagnosis and management.

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Management of massive pulmonary thromboembolism includes hemodynamic stability and medical thrombolysis.

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Successful thrombolysis can be achieved with low-dose thrombolytics in patients with higher risk of bleeding complications.

Acoustic pulse thrombolysis complemented by ECMO improved survival in patients with high-risk pulmonary embolism

BACKGROUND

The optimal treatment of high-risk pulmonary embolism (PE) with cardiac arrest is still controversial although various treatment approaches have been developed and improved. Here, we present a serie of patients with high-risk PE showing hemodynamic collapse, who were successfully treated with extracorporeal membrane oxygenation (ECMO) as an adjunct to EKOS™ acoustic pulse thrombolysis (APT).

METHODS

From April 2016 to June 2020, 29 patients with high-risk PE with cardiac arrest were retrospectively included. The mean age was 55.3 ± 9.2 years. A total of 12 (41.3%) patients were female. All patients had cardiac arrest, either as an initial presentation or in-hospital after presentation. All patients exhibited acute symptoms, computed tomography evidence of large thrombus burden, and severe right ventricular dysfunction. Primary outcome was all-cause 30-day mortality.

RESULTS

Twenty-two patients survived to hospital discharge, with a mean intensive care unit stay of 9.9 ± 1.6 days (range: 7-22 days) and mean length of hospital stay of 23.7 ± 8.5 days (range: 11-44 days). Six patients died from refractory shock. Ninety-day mortality was 24.1% (7/29). The Mean ECMO duration was 3.5 ± 1.1 days and the mean RV/LV ratio decreased from 1.31 ± 0.17 to 0.92 ± 0.11 in patients who survived to discharge. The mean tissue plasminogen activator dose for survivor patients was 20.5 ± 1.6 mg.

CONCLUSION

Patients with high-risk pulmonary embolism who suffer a cardiac arrest have high morbidity and mortality. APT complemented by ECMO could be a successful treatment option for the patients who have high-risk PE with circulatory collapse.

Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review

OBJECTIVE

Management of patients experiencing massive pulmonary embolism-related cardiac arrest is controversial. Venoarterial extracorporeal membranous oxygenation has emerged as a potential therapeutic option for these patients. We performed a systematic review assessing survival and predictors of mortality in patients with massive PE-related cardiac arrest with venoarterial extracorporeal membranous oxygenation use.

DATA SOURCES

A literature search was started on February 16, 2020, and completed on March 16, 2020, using PubMed, Embase, Cochrane Central, Cinahl, and Web of Science.

STUDY SELECTION

We included all available literature that reported survival to discharge in patients managed with venoarterial extracorporeal membranous oxygenation for massive PE-related cardiac arrest.

DATA EXTRACTION

We extracted patient characteristics, treatment details, and outcomes.

DATA SYNTHESIS

About 301 patients were included in our systemic review from 77 selected articles (total screened, n = 1,115). About 183 out of 301 patients (61%) survived to discharge. Patients (n = 51) who received systemic thrombolysis prior to cannulation had similar survival compared with patients who did not (67% vs 61%, respectively; p = 0.48). There was no significant difference in risk of death if PE was the primary reason for admission or not (odds ratio, 1.62; p = 0.35) and if extracorporeal membranous oxygenation cannulation occurred in the emergency department versus other hospital locations (odds ratio, 2.52; p = 0.16). About 53 of 60 patients (88%) were neurologically intact at discharge or follow-up. Multivariate analysis demonstrated three-fold increase in the risk of death for patients greater than 65 years old (adjusted odds ratio, 3.08; p = 0.03) and six-fold increase if cannulation occurred during cardiopulmonary resuscitation (adjusted odds ratio, 5.67; p = 0.03).

CONCLUSIONS

Venoarterial extracorporeal membranous oxygenation has an emerging role in the management of massive PE-related cardiac arrest with 61% survival. Systemic thrombolysis preceding venoarterial extracorporeal membranous oxygenation did not confer a statistically significant increase in risk of death, yet age greater than 65 and cannulation during cardiopulmonary resuscitation were associated with a three- and six-fold risks of death, respectively.

Venoarterial extracorporeal membrane oxygenation is an effective management strategy for massive pulmonary embolism patients

OBJECTIVE

Treatment of massive pulmonary embolism (MPE) is controversial, with mortality rates ranging from 25% to 65%. Patients commonly present with profound shock or cardiac arrest. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used as a form of acute cardiopulmonary support in critically ill patients. We reviewed our institution's pulmonary embolism response team experience using VA-ECMO for patients presenting with advanced shock and/or cardiac arrest from MPE.

METHODS

From March 2017 to July 2019 we retrospectively reviewed 17 consecutive patients at our institution with MPE who were placed on VA-ECMO for initial hemodynamic stabilization.

RESULTS

The mean patient age and body mass index was 55.8 years and 31.8, respectively. Ten of 17 patients (59%) required cardiopulmonary resuscitation before or during VA-ECMO cannulation. All patients had evidence of profound shock with a mean initial lactate of 8.95 mmol/L, a mean pH of 7.10, and a mean serum creatinine of 1.78 mg/dL. Seventeen of 17 cannulations (100%) were performed percutaneously, with 41% (n = 7) of patients placed on VA-ECMO while awake and using local analgesia. Five of 17 patients (29%) required reperfusion cannulas, with 0% incidence of limb loss. Overall survival was 13 of 17 patients (76%), with causes of death resulting from anoxic brain injury (n = 2), septic shock (n = 1), and cardiopulmonary resuscitation-induced hemorrhage from liver laceration (n = 1). In survivors, 12 of 13 patients (92%) were discharged without evidence of neurologic insult. The median duration of the VA-ECMO run for survivors was 86 hours (range, 45-218 hours). In survivors, the median length of time from ECMO cannulation to lactate clearance (<2.0 mmol/L) was 10 hours and the median length of time from ECMO cannulation to freedom from vasopressors was 6 hours. Three of 13 patients (23%) required concomitant percutaneous thrombectomy and catheter-directed thrombolysis to address persistent right heart dysfunction, with the remaining survivors (77%) receiving VA-ECMO and anticoagulation alone as definitive therapy for their MPE. The median intensive care and hospital length of stay for survivors was 9 and 13 days, respectively.

CONCLUSIONS

VA-ECMO was effective at salvaging highly unstable patients with MPE. Survivors had rapid reversal of multiple organ failure with ECMO as their primary therapy. The majority of survivors required ECMO and anticoagulation alone for definitive therapy of their MPE.

Massive Fatal Pulmonary Embolism While on Therapeutic Heparin Drip

Venous thromboembolism (VTE) includes deep venous thrombosis (DVT) and pulmonary embolism (PE). In this article, we present a case of a patient with an acute DVT who was treated with a therapeutic heparin drip, then developed syncope while in the hospital and found to have massive bilateral PEs. This case aims to arouse the medical staff’s awareness of the VTE diagnosis even if the patient is fully anticoagulated. We review the indications for DVT hospitalization, heparin infusion monitoring, risk factors for developing PE from DVT, mechanisms of developing PE from DVT while on therapeutic anticoagulation, and signs and treatment of massive PE.

Cardiac arrest from massive PE in nephrotic syndrome successfully treated with embolectomy and ECMO

Pulmonary emboli (PE) are commonly encountered events with presentations ranging from benign incidental findings to obstructive shock. We present a case of a 20 year old male with nephrotic syndrome who suffered complete cardiovascular collapse with cardiac arrest in the setting of a massive PE, requiring open surgical embolectomy and ECMO support. We reviewed the literature on massive PE's focusing on the use of ECMO and success of the rarely performed open embolectomy for the treatment of obstructive shock from a massive PE.

Saddle pulmonary embolus resulting in cardiovascular collapse requiring extracorporeal membrane oxygenation in a postoperative patient with endometrial cancer

Background

Venous thromboembolism after open gynecologic surgery is not uncommon, especially in the presence of other risk factors such as obesity, prolonged surgical time or gynecologic malignancy.

Case

We present the case of a 62 y.o. patient who underwent open hysterectomy and surgical staging for uterine serous carcinoma. She was readmitted with lower extremity edema. During her workup, she underwent cardiovascular arrest secondary to saddle pulmonary embolus requiring cardiopulmonary resuscitation and extracorporeal membrane oxygenation. After systemic and catheter directed thrombolysis, and a long hospitalization, she was discharged home in stable condition.

Conclusion

Saddle pulmonary embolus is a potentially catastrophic and fatal postoperative complication. This case demonstrates a successful implementation of directed thrombolysis, veno-arterial extracorporeal membrane oxygenation and multidisciplinary management in a case of postoperative saddle pulmonary embolus.

Précis

We report a case of an endometrial cancer patient who sustained a massive postoperative pulmonary embolus and was successfully resuscitated using extracorporeal membrane oxygenation.

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Extracorporeal membrane oxygenation can help stabilize patients with massive embolus.

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Catheter directed alteplase may reduce risk of bleeding compared to systemic therapy.

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A multidisciplinary approach to massive saddle embolus may improve patient outcomes.

Surgical Embolectomy for Massive and Submassive Pulmonary Embolism and Pulmonary Thromboendarterectomy for Chronic Thromboembolic Pulmonary Hypertension

Surgical therapy for massive acute pulmonary embolism has improved with the use of rapid response teams and selective bedside extracorporeal membrane oxygenation initiation. The chronic consequence of unresolved pulmonary embolism is a treatable form of pulmonary hypertension. Pulmonary thromboendarterectomy is a curative operation in selected cases, operated upon in an experienced center with the multidisciplinary team including imaging, pulmonary medicine, and cardiothoracic surgery.

Successful Management of Intraoperative Acute Bilateral Pulmonary Embolism in a High Grade Astrocytoma Patient

Patient: Female, 39

Final Diagnosis: Acute bilateral pulmonary embolism

Symptoms: Headache • amnesia • seizure • urinary incontinence

Medication: —

Clinical Procedure: —

Specialty: Anesthesiology

Extracorporeal membrane oxygenation in acute massive pulmonary embolism: a systematic review

Massive pulmonary embolism (PE) can present with extreme physiological dysfunction, characterised by acute right ventricular failure, hypoxaemia unresponsive to conventional therapy and cardiac arrest. Consensus regarding the management of patients with persistent shock following thrombolysis is lacking. Our primary objective was to describe the application of extracorporeal membrane oxygenation (ECMO) in the treatment of acute massive PE. We were unable to identify any randomised controlled trials (RCTs) comparing ECMO with other support systems in the setting of massive PE. We reviewed case reports and case series published in the past 20 years to evaluate the mortality rate and any poor prognostic factors. Overall survival was 70.1% and none of the definitive treatment modalities was associated with a higher mortality (thrombolysis - OR - 0.99, P - 0.9, catheter embolectomy - OR - 1.01, P - 0.99, surgical embolectomy - OR - 0.44, P - 0.20). Patients who had ECMO instituted whilst in cardiorespiratory arrest had a higher risk of death. (OR - 16.71, P - 0.0004). When compared with other causes of cardiac arrest, patients who survived a massive PE presented a good neurological outcome (cerebral performance category 1 or 2).

Extracorporeal life support (ECLS) for cardiopulmonary resuscitation (CPR) with pulmonary embolism in surgical patients – a case series

Background:

Extracorporeal life support (ECLS) devices maintain the circulation and oxygenation of organs during acute right ventricular failure and cardiogenic shock, bypassing the lungs. A pulmonary embolism can cause this life-threatening condition. ECLS is a considerably less invasive treatment than surgical embolectomy. Whether to bridge embolectomy or for a therapeutic purpose, ECLS is used almost exclusively following failure of all other therapeutic options.

Methods:

From January 1, 2008 to June 30, 2014, five patients in cardiac arrest and with diagnosed pulmonary embolism (PE) were cannulated with the ECLS system.

Results:

PE was diagnosed using computer tomography scanning or echocardiography. Cardiac arrest was witnessed in the hospital in all cases and CPR (cardiopulmonary resuscitation) was initiated immediately. Cannulation of the femoral vein and femoral artery was always performed under CPR conditions. Right heart failure regressed during the ECLS therapy, usually under a blood flow of 4-5 L/min after 48 hours. Three patients were weaned from ECLS and one patient became an organ donor. Finally, two of the five PE patients treated with ECLS were discharged from inpatient treatment without neurological dysfunction. The duration of ECLS therapy depends on the patient’s condition. Irreversible damage to the organs after hypoxemia limits ECLS treatment and leads to futile multiorgan failure. Hemorrhages after thrombolysis and cerebral dysfunction were further complications.

Conclusions:

Veno-arterial cannulation for ECLS can be feasibly achieved and should be established during active CPR for cardiac arrest. In the case of PE, the immediate diagnosis and rapid implantation of the system are decisive for therapeutic success.

Pig Model of Pulmonary Embolism: Where Is the Hemodynamic Break Point?

Early recognition of collapsing hemodynamics in pulmonary embolism is necessary to avoid cardiac arrest using aggressive medical therapy or mechanical cardiac support. The aim of the study was to identify the maximal acute hemodynamic compensatory steady state. Overall, 40 dynamic obstructions of pulmonary artery were performed and hemodynamic data were collected. Occlusion of only left or right pulmonary artery did not lead to the hemodynamic collapse. When gradually obstructing the bifurcation, the right ventricle end-diastolic area expanded proportionally to pulmonary artery mean pressure from 11.6 (10.1, 14.1) to 17.8 (16.1, 18.8) cm2 (p<0.0001) and pulmonary artery mean pressure increased from 22 (20, 24) to 44 (41, 47) mmHg (p<0.0001) at the point of maximal hemodynamic compensatory steady state. Similarly, mean arterial pressure decreased from 96 (87, 101) to 60 (53, 78) mmHg (p<0.0001), central venous pressure increased from 4 (4, 5) to 7 (6, 8) mmHg (p<0.0001), heart rate increased from 92 (88, 97) to 147 (122, 165) /min (p<0.0001), continuous cardiac output dropped from 5.2 (4.7, 5.8) to 4.3 (3.7, 5.0) l/min (p=0.0023), modified shock index increased from 0.99 (0.81, 1.10) to 2.31 (1.99, 2.72), p<0.0001. In conclusion, instead of continuous cardiac output all of the analyzed parameters can sensitively determine the individual maximal compensatory response to obstructive shock. We assume their monitoring can be used to predict the critical phase of the hemodynamic status in routine practice.

[Arteriovenous extracorporeal membrane oxygenation (ECMO). A therapeutic option for fulminant pulmonary embolism]

According to the guidelines of the European (2008) and German Societies of Cardiology (2009) thrombolysis is recommended for patients with pulmonary embolisms presenting with cardiogenic shock (recommendation level I, evidence level A). If there are contraindications or thrombolysis is not successful surgical embolectomy should be considered (recommendation level I, evidence level C). Additional options are catheter-based therapies in the proximal pulmonary artery (recommendation level IIb, evidence level C). The use of arteriovenous extracorporeal membrane oxygenation ( ECMO) was not included in these guidelines. A literature search in PubMed resulted in some case reports of the successful use of arteriovenous ECMO for resuscitation in patients with severe pulmonary embolisms following failed thrombolysis. In this article we present the case report of a patient who developed fulminant pulmonary embolism immediately after surgery. The patient was still in cardiogenic shock despite thrombolysis but the condition was stable following implementation of an arteriovenous ECMO. Acute heart failure and hypoxemia of all organs are the main symptoms of massive pulmonary embolisms. The use of arteriovenous ECMO represents a therapeutic option for life-threatening pulmonary embolism. A decisive factor for success is immediate diagnosis and rapid implementation of the system.

Successful use of extracorporeal membrane oxygenation in a patient with combined pulmonary and systemic embolisation

We present a highly unusual case of massive pulmonary embolism with secondary paradoxical systemic embolisation that was successfully resuscitated with veno-arterial extracorporeal membrane oxygenation (ECMO). This enabled subsequent successful bridging to pulmonary embolectomy.

Improved outcome of surgical pulmonary embolectomy by aggressive intervention for critically ill patients

BACKGROUND

Acute massive pulmonary thromboembolism is a life-threatening disorder, and prompt treatment is necessary. We analyzed the outcome of pulmonary embolectomy for massive pulmonary embolism.

METHODS

Nineteen patients who underwent pulmonary embolectomy were retrospectively investigated. Average age of patients was 59 years, and 79% were female. Most patients had massive or submassive pulmonary thromboemboli dislodging into the main pulmonary trunk or bilateral main pulmonary arteries. Hemodynamics of most patients were unstable. Two patients required percutaneous cardiopulmonary support before embolectomy, and 4 required cardiopulmonary resuscitation. In 6 patients, thrombolysis was ineffective.

RESULTS

All patients underwent emergent pulmonary embolectomy. Operative mortality was 5.3%. No patients exhibited newly developed neurologic damage. Ten-year survival rate was 83.5% ± 8.7%.

CONCLUSIONS

Pulmonary embolectomy saves critically ill patients having acute massive pulmonary thromboembolism. We must evaluate pulmonary embolism patients with an algorithm that includes surgical embolectomy as one of several therapeutic options.

Successful Treatment of Peripartum Massive Pulmonary Embolism with Extracorporeal Membrane Oxygenation and Catheter-Directed Pulmonary Thrombolytic Therapy

Chronic thromboembolic pulmonary hypertension during pregnancy is uncommon but is associated with maternal mortality in excess of 35%. We report a case of decompensated thromboembolic pulmonary hypertension requiring emergency caesarean section and postpartum treatment with extracorporeal membrane oxygenation and thrombolytic therapy with urokinase. The use of extracorporeal membrane oxygenation, catheter-directed pulmonary thrombolytic therapy and other pulmonary vasodilators for management of this life-threatening disease is discussed.

Anaesthesia and right ventricular failure

Acute right ventricular (RV) failure has until recently received relatively little attention in the cardiology, critical care or anaesthesia literature. However, it is frequently encountered in cardiac surgical cases and is a significant cause of mortality in patients with severe pulmonary hypertension who undergo non-cardiac surgery. RV dysfunction may be primarily due to impaired RV contractility, or volume or pressure overload. In these patients, an increased pulmonary vascular resistance (PVR) or a decreased aortic root pressure may lead to RV ischaemia, resulting in a rapid, downward haemodynamic spiral. The key aspects of 'RV protection' in patients who are at risk of perioperative decompensation are prevention, detection and treatment aimed at reversing the underlying pathophysiology. Minimising PVR and maintaining systemic blood pressure are of central importance in the prevention of RV decompensation, which is characterised by a rising central venous pressure and a falling cardiac output. Although there are no outcome data to support any therapeutic strategy for RV failure when PVR is elevated, the combination of inhaled iloprost or intravenous milrinone with oral sildenafil produces a synergistic reduction in PVR, while sparing systemic vascular resistance. Levosimendan is a promising new inotrope for the treatment of RV failure, although its role in comparison to older agents such as dobutamine, adrenaline and milrinone has yet to be determined. This is also the case for the use of vasopressin as an alternative pressor to noradrenaline. If all else has failed, mechanical support of the RV should be considered in selected cases.

A porcine model of massive, totally occlusive, pulmonary embolism

BACKGROUND

A reliable, animal model of massive, totally occlusive, pulmonary embolism (PE) is lacking.

OBJECTIVES

To design an animal model of totally occlusive PE and to challenge the model by a plasminogen activator.

METHODS

In eight anaesthetized pigs (approximately 90 kg) a massive preformed autologous thrombus was injected into the caval vein. One animal was autopsied to assess the extent of injected clot, whereas in the other animals extracorporeal life support (ECLS) was initiated and continued for three hours. These animals received 100 mg rt-PA. Blood gases, coagulation tests, creatine kinase (CK), lactate dehydrogenase (LDH), end-tidal CO2, systemic and pulmonary artery blood pressures and flow were registered.

RESULTS

All animals went into circulatory arrest within 2 minutes after injection of the thrombus. In the animal where ECLS was not started, autopsy relieved a totally occlusive embolus of the pulmonary artery. The ECLS maintained a systemic blood flow of 6-8 L/min with adequate oxygenation and CO2-removal. However, lactate increased and base-excess became negative. Ddimer increased, fibrinogen decreased, and CK and LDH increased. All seven animals were weaned from ECLS. Despite the rt-PA treatment, the animals had at that time low end tidal CO2/PaCO2 ratio and increased mean pulmonary arterial pressure, suggesting a significant amount of embolic material remaining in the pulmonary artery.

CONCLUSION

This model of massive, totally occlusive, pulmonary embolism mimics well fatal PE seen in the clinic, and has the potential for use in testing of new therapeutic interventions.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

Extracorporeal membrane oxygenation with danaparoid sodium after massive pulmonary embolism

During extracorporeal membrane oxygenation, anticoagulation therapy is usually achieved with unfractionated heparin. We report on an extracorporeal membrane oxygenation with danaparoid sodium for a patient with severe respiratory failure due to massive pulmonary embolism and suspected type 2 heparin-induced thrombocytopenia. Danaparoid, a low molecular weight heparinoid, is an alternative to heparin for patients who develop type 2 heparin-induced thrombocytopenia. Danaparoid was given at 400 IU/h with an objective of antifactor Xa activity of 0.6-0.8 U/mL, which was monitored twice a day. No excessive bleeding or clotting of the circuit was noted. The patient was weaned from extracorporeal membrane oxygenation after 9 days of treatment.

Cardiopulmonary bypass as an adjunct for the noncardiac surgeon

The use of cardiopulmonary bypass (CPB) in noncardiac surgical settings has been increasingly developed and has greatly benefited noncardiac surgeon. A few years after the advent of CPB as well as profound hypothermic circulatory arrest in the early years, it was employed by neurosurgeons in cerebrovascular surgery and by general thoracic surgeons in carinal tumor resection. Indications for CPB were extended and modified year after year. It has facilitated not only the surgical management by surgeons of lesions that cannot be managed safely and effectively by conventional techniques, or conventional techniques carry significant risks to the patient, but also the preservation of the viability of multiple organ procurement, the practice of isolated limb perfusion for the treatment of malignancies of the extremities, and emergent cardiopulmonary resuscitation. Owing to the complications arising from CPB and profound hypothermic circulatory arrest, such as postoperative bleeding, coagulopathy, and neurologic deficits, efforts have been made to avoid these common hazards. Thus, innovative techniques including extracorporeal membrane oxygenation, percutaneous cardiopulmonary support, venovenous bypass, normothermic CPB, and minimally invasive approaches have emerged and played an important role as alternatives of standard CPB in decreasing morbidity and mortality and improving survival.

Off-Pump Open Pulmonary Embolectomy for Patients with Major Pulmonary Embolism

Acute major pulmonary artery embolism (AMPE) requires rapid diagnosis and early intensive treatment to optimize patient outcomes. Most patients with AMPE and hemodynamic instability need open pulmonary embolectomy (OPE). We modified the technique of OPE to include a minimally invasive procedure without the use of cardiopulmonary bypass (CPB). From March 1988 to April 2006, we performed OPE on a total of 12 patients (21 sides) with AMPE. Seven patients (13 sides) underwent conventional OPE with CPB and 5 patients underwent off-pump OPE (OPPE), 4 (8 sides) with AMPE and 1 with catheter embolus with thrombosis. In patients who underwent conventional OPE, there was 1 hospital death in a patient with severe right ventricle dysfunction and 2 significant cases of airway bleeding. In patients who underwent OPPE, there was 1 case of minimal airway bleeding. Mean systolic pulmonary artery pressure in conventional OPE and OPPE patients, respectively, decreased from 50.3 +/- 14 mmHg and 35.4 +/- 6.6 mmHg pre-operatively to 41.7 +/- 20 and 28 +/- 3 mmHg postoperatively. During the long-term follow-up, there were 2 cancer-related deaths but no recurrence of PE. All surviving patients maintained functional class I (n = 10) or II (n = 1). Compared with conventional OPE, OPPE was effective for treating AMPE in our selected cases. Modification of conventional CPB and systemic full heparinization to minimal use of systemic heparinization without CPB may be helpful in treating selected patients with AMPE.

Extracorporeal Life Support for Massive Pulmonary Embolism

BACKGROUND

Massive pulmonary embolism is frequently lethal because of acute irreversible pulmonary and cardiac failure. Extracorporeal life support (ECLS) has been used for cardiopulmonary failure in our institution since 1988, and we reviewed our experience with its use in the management of massive pulmonary emboli.

METHODS

We reviewed our complete experience with ECLS for massive pulmonary emboli from January 1992 through December 2005. The records of 21 patients were examined and data extracted.

RESULTS

During the study period, 21 patients received ECLS for massive pulmonary emboli. All patients were on vasoactive drugs, acidemic, and hypoxic at the time of institution of ECLS. Eight were in active cardiac arrest. Five were trauma patients, eight had recently undergone an operation, and six had a hypercoagulable disorder. Nineteen of the 21 patients were cannulated for venoarterial bypass and two were placed on venovenous bypass. The average duration of support for survivors was 5.4 days, ranging from 5 hours to 12.5 days. Emboli resolved with anticoagulation in 10 of 13 survivors and 4 of 13 survivors underwent surgical pulmonary embolectomy. Catastrophic neurologic events were the most common cause of mortality in our series; four patients died from intracranial hemorrhage. The overall survival rate was 62% (13/21).

CONCLUSIONS

We conclude that emergent ECLS provides an opportunity to improve the prognosis of an otherwise near-fatal condition, and should be considered in the algorithm for management of a massive pulmonary embolism in an unstable patient.

A case report of severe tracheal obstruction requiring extracorporeal membrane oxygenation

The authors describe the case of a near-fatal airway obstruction requiring extracorporeal membrane oxygenation. The patient presented with severe respiratory distress owing to a bean impacted in the distal trachea. The foreign body could not be removed by bronchoscopy because of instability of the patient. The patient was placed on extracorporeal membrane oxygenation for temporary pulmonary support, and the foreign body was removed using a rigid bronchoscope. The patient had a full recovery and suffered no neurologic sequelae.

Percutaneous cardiopulmonary bypass for cardiac emergencies

Percutaneous cardiopulmonary support systems (PCPS) are compact, battery-powered, portable heart-lung machines that can be implemented rapidly in any area of the hospital using thin-walled cannulae inserted via the femoral vessels. PCPS provides temporary circulatory support by actively aspirating blood from the patient's venous system using a centrifugal pump and hollow fiber membrane oxygenator for gas exchange. A review of clinical reports has delineated several indications for emergent applications, with the most frequent being cardiac arrest (CA) or cardiogenic shock (CS). Survival is more likely in patients with CS (40%) compared to CA (21%). Implementation of PCPS after unwitnessed CA or cardiopulmonary resuscitation > 30 min yields a patient survival rate of < 10%. The likelihood of patient survival after emergent PCPS is most often related to the patient undergoing a definitive anatomic surgical repair such as coronary artery bypass or pulmonary embolectomy. If the need for circulatory support extends beyond 6 h, conversion to conventional long-term extracorporeal membrane oxygenation or a ventricular assist device is recommended.

Pulmonary embolism

Pulmonary embolism (PE) is a common problem for which prompt diagnosis and treatment is essential to minimize mortality. The clinical presentation is more variable than sudden dyspnea and chest pain, especially in the critical care patient. Recognition of venous thromboembolic (VTE) risk factors can help develop a good clinical suspicion for PE. A wide range of diagnostic tests are available to the clinician. The ventilation/perfusion scan, pulmonary arteriogram, and lower extremity investigations are still important for diagnosis. Other noninvasive tests such as spiral CT with venography, echocardiography, and D-dimers are becoming more accepted. Heparin is the mainstay of PE therapy, but thrombolytic treatment may be lifesaving in the unstable patient. VTE prophylaxis should be considered in all post-operative or critical care patients.