Short-term venoarterial extracorporeal membrane oxygenation for massive endobronchial hemorrhage after pulmonary endarterectomy

Pulmonary Thromboendarterectomy: The Potentially Curative Treatment of Choice for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a consequence of unresolved organized thromboembolic obstruction of the pulmonary arteries, which can cause pulmonary hypertension and right ventricular failure. Owing to its subtle signs, determining its exact incidence and prevalence is challenging. Furthermore, CTEPH may also present without any prior venous thromboembolic history, contributing to underdiagnosis and undertreatment. Diagnosis requires a high degree of suspicion and is ruled out by a normal ventilation/perfusion ratio scintigraphy. Additional imaging by computed tomography and/or conventional angiography, as well as right heart catheterization, are required to confirm CTEPH and formulate treatment plans. Pulmonary thromboendarterectomy is the treatment of choice for eligible patients and can be potentially curative. Pulmonary thromboendarterectomy has a low mortality rate of 1% to 2% at expert centers and offers excellent long-term survival. Furthermore, recent advances in the techniques allow distal endarterectomy with comparable outcomes. Alternative treatment options are available for those who may not be operable or have prohibitive risks, providing some benefit. However, CTEPH is a progressive disease with low long-term survival rates if left untreated. Given excellent short- and long-term outcomes of surgery, as well as the benefits seen with other treatment modalities in noncandidate patients, it is crucial that precapillary pulmonary hypertension and CTEPH are ruled out in any patient with dyspnea of unexplained etiology. These patients should be referred to expert centers where accurate operability assessment and appropriate treatment strategies can be offered by a multidisciplinary team.

Chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary hypertension is a complication of pulmonary embolism and a treatable cause of pulmonary hypertension. The pathology is a unique combination of mechanical obstruction due to failure of clot resolution, and a variable degree of microvascular disease, that both contribute to pulmonary vascular resistance. Accordingly, multiple treatments have been developed to target the disease components. However, accurate diagnosis is often delayed. Evaluation includes high-quality imaging modalities, necessary for disease confirmation and for appropriate treatment planning. All patients with chronic thromboembolic pulmonary disease, and especially those with pulmonary hypertension, should be referred to expert centres for multidisciplinary team decision on treatment. The first decision remains assessment of operability, and the best improvement in symptoms and survival is achieved by the mechanical therapies, pulmonary endarterectomy and balloon pulmonary angioplasty. With the advances in multimodal therapies, excellent outcomes can be achieved with 3-year survival of >90%.

How Would I Treat My Own Chronic Thromboembolic Pulmonary Hypertension in the Perioperative Period?

Chronic thromboembolic pulmonary hypertension (CTEPH) results from an incomplete resolution of acute pulmonary embolism, leading to occlusive organized thrombi, vascular remodeling, and associated microvasculopathy with pulmonary hypertension (PH). A definitive CTEPH diagnosis requires PH confirmation by right-heart catheterization and evidence of chronic thromboembolic pulmonary disease on imaging studies. Surgical removal of the organized fibrotic material by pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest represents the treatment of choice. One-third of patients with CTEPH are not deemed suitable for surgical treatment, and medical therapy or interventional balloon pulmonary angioplasty presents alternative treatment options. Pulmonary endarterectomy in patients with technically operable disease significantly improves symptoms, functional capacity, hemodynamics, and quality of life. Perioperative mortality is <2.5% in expert centers where a CTEPH multidisciplinary team optimizes patient selection and ensures the best preoperative optimization according to individualized risk assessment. Despite adequate pulmonary artery clearance, patients might be prone to perioperative complications, such as right ventricular maladaptation, airway bleeding, or pulmonary reperfusion injury. These complications can be treated conventionally, but extracorporeal membrane oxygenation has been included in their management recently. Patients with residual PH post-PEA should be considered for medical or percutaneous interventional therapy.

Perioperative extracorporeal membrane oxygenation support for pulmonary endarterectomy: A 17-year experience from the UK national cohort

BACKGROUND

Pulmonary endarterectomy (PEA) is the guideline-recommended treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, some patients develop severe cardiopulmonary compromise before surgery, intraoperatively, or early postoperatively. This may result from advanced CTEPH, reperfusion pulmonary edema, massive endobronchial bleeding, or right ventricular (RV) failure secondary to residual pulmonary hypertension. Conventional cardiorespiratory support is ineffective when these complications are severe. Since 2005, we used extracorporeal membrane oxygenation (ECMO) as a rescue therapy for this group. We review our experience with ECMO support in these patients.

METHODS

This study was a retrospective analysis of patients who received perioperative ECMO for PEA from a single national center from August 2005 to July 2022. Data were prospectively collected.

RESULTS

One hundred and ten patients (4.7%) had extreme cardiorespiratory compromise requiring perioperative ECMO. Nine were established on ECMO before PEA. Of those who received ECMO postoperatively, 39 were for refractory reperfusion lung injury, 20 for RV failure, 31 for endobronchial bleeding, and the remaining 11 were for "other" reasons, such as cardiopulmonary resuscitation following late tamponade and aspiration pneumonitis. Sixty-two (56.4%) were successfully weaned from ECMO. Fifty-seven patients left the hospital alive, giving a salvage rate of 51.8%. Distal disease (Jamieson Type III) and significant residual pulmonary hypertension were also predictors of mortality on ECMO support. Overall, 5- and 10-year survival in patients who were discharged alive following ECMO support was 73.9% (SE: 6.1%) and 58.2% (SE: 9.5%), respectively.

CONCLUSIONS

Perioperative ECMO support has an appropriate role as rescue therapy for this group. Over 50% survived to hospital discharge. These patients had satisfactory longer-term survival.

Review of anticoagulation considerations in extracorporeal membrane oxygenation support

Since its first success in 1975, extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency for pulmonary and cardiopulmonary bypass. Use in adults has increased exponentially since the early 2000s, but despite thousands of international cannulations using both veno-arterial (VA) and veno-venous (VV) ECMO, there are still significant hemocompatibility-related adverse events. Current management of anticoagulation has been based on the Extracorporeal Life Support Organization guidance published in 2014 with recent updates published in 2022. Despite this guidance, there is still limited international consensus on how to manage anticoagulation in ECMO. For this review, we completed a comprehensive search of multiple electronic databases to identify studies pertaining to anticoagulation of adult patients on VV or VA-ECMO. The highest priority was given to sources that were prospective, randomized, controlled studies, but in the absence of such resources, observational studies, retrospective uncontrolled studies, and case series/reports were considered for inclusion. This document serves to provide a comprehensive review of the current understanding of management pertaining to anticoagulation relating to ECMO.

Extracorporeal Life Support in Pulmonary Hypertension: Practical Aspects

Extracorporeal life support (ECLS), in particular veno-arterial extracorporeal membrane oxygenation, has emerged as a potentially life-saving treatment modality in patients presenting with pulmonary hypertension and right heart failure refractory to conventional treatment. Used mainly as a bridge to lung transplantation, ECLS is also being used occasionally as a bridge to recovery in patients with treatable causes of right heart failure. This review article describes indications, contraindications, techniques, and outcomes of the use of ECLS in patients with PH, focusing on practical aspects in the management of such patients.

Highlights from the International Chronic Thromboembolic Pulmonary Hypertension Congress 2021

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. It is caused by persistent obstruction of pulmonary arteries by chronic organised fibrotic clots, despite adequate anticoagulation. The pulmonary hypertension is also caused by concomitant microvasculopathy which may progress without timely treatment. Timely and accurate diagnosis requires the combination of imaging and haemodynamic assessment. Optimal therapy should be individualised to each case and determined by an experienced multidisciplinary CTEPH team with the ability to offer all current treatment modalities. This report summarises current knowledge and presents key messages from the International CTEPH Conference, Bad Nauheim, Germany, 2021. Sessions were dedicated to 1) disease definition; 2) pathophysiology, including the impact of the hypertrophied bronchial circulation, right ventricle (dys)function, genetics and inflammation; 3) diagnosis, early after acute pulmonary embolism, using computed tomography and perfusion techniques, and supporting the selection of appropriate therapies; 4) surgical treatment, pulmonary endarterectomy for proximal and distal disease, and peri-operative management; 5) percutaneous approach or balloon pulmonary angioplasty, techniques and complications; and 6) medical treatment, including anticoagulation and pulmonary hypertension drugs, and in combination with interventional treatments. Chronic thromboembolic pulmonary disease without pulmonary hypertension is also discussed in terms of its diagnostic and therapeutic aspects.

Preoperative pulmonary vascular resistance and neutrophil-to-lymphocyte ratio predict the demand of extracorporeal membrane oxygenation after pulmonary endarterectomy

BACKGROUND

Acute respiratory and circulatory collapse might occasionally happen after pulmonary endarterectomy (PEA). We aimed to investigate the utilization of extracorporeal membrane oxygenation (ECMO) after PEA and potential risk factors.

METHODS

Demographic characteristics, clinical and surgical data were collected for all patients who underwent PEA from December 2016 to June 2022. All factors were compared between patients in the ECMO group and those in the other group. The most characteristic risk factors were obtained by least absolute shrinkage and selection operator regression and support vector machine machine learning, and receiver operating characteristics (ROC) Curve analysis was performed to verify the diagnostic value of the obtained risk factors.

RESULTS

A total of 117 patients underwent PEA, and 8 (6.8%) of them received ECMO treatment intraoperatively or postoperatively. There were significant differences between the two groups in terms of cardiac function, pulmonary vascular resistance (PVR), preoperative inflammation and cardiopulmonary bypass time. The PVR and neutrophil-to-lymphocyte ratio (N/L ratio) were the most characteristic risk factors with an area under the ROC curve of 0.847 (95% confidence interval [CI] = 0.7517-0.9420, p = .005) and 0.896 (95% CI = 0.803-0.989, p = .001), respectively. The ECMO group had higher PVR (1549.4 ± 600.7 vs. 952.9 ± 466.9 dyn.s.cm^-5 , p = .004) and N/L ratio (6.3 ± 5.6 vs. 2.4 ± 1.7, p = .001).

CONCLUSIONS

PVR and N/L ratio can correctly predict who is likely to receive ECMO treatment after PEA. Therefore, addressing the preoperative inflammatory status might be beneficial but further research is needed.

Does Age Matter? Pulmonary Endarterectomy in the Elderly Patient with CTEPH

BACKGROUND

The gold standard treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA). Little is known about the influence of advanced age on surgical outcome. Therefore, the aim of this study was to investigate the impact of patient's age on postoperative morbidity, mortality, and quality of life in a German referral center.

METHODS

Prospectively collected data from 386 consecutive patients undergoing PEA between 01/2014 and 12/2016 were analyzed. Patients were divided into three groups according to their age: group 1: ≤ 50 years, group 2: > 50 ≤ 70 years, group 3: > 70 years.

RESULTS

After PEA, distinct improvements in pulmonary hemodynamics, physical capacity (World Health Organization [WHO] functional class and 6-minute walking distance) and quality of life were found in all groups. There were more complications in elderly patients with longer time of invasive ventilation, intensive care, and in-hospital stay. However, the in-hospital mortality was comparable (0% in group 1, 2.6% in group 2, and 2.1% in group 3 [p = 0.326]). Furthermore, the all-cause mortality at 1 year was 1.1% in group 1, 3.2% in group 2, and 6.3% in group 3 (p = 0.122).

CONCLUSIONS

PEA is an effective treatment for CTEPH patients of all ages accompanied by low perioperative and 1-year mortality. CTEPH patients in advanced age carefully selected by thorough preoperative evaluation should be offered PEA in expert centers to improve quality of life, symptoms, and pulmonary hemodynamics.

Pulmonary endarterectomy: technique and pitfalls

Chronic thromboembolic pulmonary hypertension (CTEPH) remains a rare and underdiagnosed disease. After one or several episodes of acute pulmonary embolism, around 3% of patients develop CTEPH and two-thirds of these patients are potential surgical candidates. Besides surgery, additional treatment modalities are pulmonary arterial hypertension medication and balloon pulmonary angioplasty. Patients should be evaluated in CTEPH expert centers to ensure the most appropriate therapy. Pulmonary endarterectomy (PEA) is a complex, but standardized surgical procedure aiming to clear the obstructed pulmonary arteries completely. For optimal visualization, deep hypothermic circulatory arrest is a prerequisite. This article will give an overview of the evaluation, indication and surgical management of patients with CTEPH.

Pulmonary endarterectomy

Chronic thromboembolic pulmonary hypertension is an underdiagnosed condition. Patients typically present with the symptoms of right heart failure. Diagnosis is usually done by radionuclide ventilation/perfusion (VQ) scan, high-quality multidetector computed tomography (CT) or pulmonary angiography at expert centers. Pulmonary endarterectomy remains the corner stone in management of chronic thromboembolic pulmonary hypertension. Deep hypothermic circulatory arrest is commonly used for the operation at most centers. In-hospital mortality ranges from 1.7 to 14.2%. Pulmonary hemorrhage, reperfusion lung injury, and right ventricular failure remain major early post-operative concerns. Five-year survival is reported to be 76 to 89%. Long-term outcome depends on residual pulmonary hypertension. Balloon pulmonary angioplasty and medical management play an adjunctive role. Here, we provide a comprehensive review on surgical management of chronic thromboembolic pulmonary hypertension.

Experience with pulmonary endarterectomy: Lessons learned across 17 years

BACKGROUND

Pulmonary endarterectomy is potential curative therapy for chronic thromboembolic pulmonary hypertension patients. Here, we present our experience with pulmonary endarterectomy spanning 17 years and detail our management strategy.

METHODS

This is a single-centre retrospective study conducted on chronic thromboembolic pulmonary hypertension patients who underwent pulmonary endarterectomy at our centre across 17 years.

RESULTS

Between 2004 and 2020, 591 patients underwent pulmonary endarterectomy. Amongst them 429 (72.4%) were males with a male to female ratio of 2.6:1, the median age was 38 (range, 14-73) years. The median length of hospital stay was 11 days (IQR, 8-16). Extra corporeal membranous oxygenation was used in 82 (13.9%) patients during/after surgery, out of whom 28 (34.1%) survived. There were 70 (11.8%) in-hospital deaths. Female gender (p < 0.01), pulmonary artery systolic pressure >100 mmHg (p < 0.05) and use of extra corporeal membrane oxygenation (p < 0.001) were significant risk factors for in-hospital mortality. The mortality in the first period (2004-2012) was 15.7% which reduced to 9.1% in the later period (2013-2020). The reduction in mortality rate was 42% (p < 0.05). Following pulmonary endarterectomy, there was a significant reduction in pulmonary artery systolic pressure (86.68 ± 24.38 vs. 39.71 ± 13.13 mmHg; p < 0.001) and improvement in median walk distance as measured by 6-min walk test on follow-up (300 vs. 450 meters; p < 0.001). The median duration of follow-up was 8 months (inter-quartile range: 2-24).

CONCLUSIONS

pulmonary endarterectomy has a learning curve, high pulmonary vascular resistance alone is not a contraindication for surgery. Patients following surgery have improved survival and quality of life.

Extracorporeal Life Support in Hemorrhagic Conditions: A Systematic Review

Extracorporeal life support (ECLS) is indicated in refractory acute respiratory or cardiac failure. According to the need for anticoagulation, bleeding conditions (e.g., in trauma, pulmonary bleeding) have been considered a contraindication for the use of ECLS. However, there is increasing evidence for improved outcomes after ECLS support in hemorrhagic patients based on the benefits of hemodynamic support outweighing the increased risk of bleeding. We conducted a systematic literature search according to the PRISMA guidelines and reviewed publications describing ECLS support in hemorrhagic conditions. Seventy-four case reports, four case series, seven retrospective database observational studies, and one preliminary result of an ongoing study were reviewed. In total, 181 patients were identified in total of 86 manuscripts. The reports included patients suffering from bleeding caused by pulmonary hemorrhage (n = 53), trauma (n = 96), postpulmonary endarterectomy (n = 13), tracheal bleeding (n = 1), postpartum or cesarean delivery (n = 11), and intracranial hemorrhage (n = 7). Lower targeted titration of heparin infusion, heparin-free ECLS until coagulation is normalized, clamping of the endotracheal tube, and other ad hoc possibilities represent potential beneficial maneuvers in such conditions. Once the patient is cannulated and circulation restored, bleeding control surgery is performed for stabilization if indicated. The use of ECLS for temporary circulatory or respiratory support in critical patients with refractory hemorrhagic shock appears feasible considering tailored ECMO management strategies. Further investigation is needed to better elucidate the patient selection and ECLS management approaches.

Extracorporeal membrane oxygenation without systemic anticoagulation: a case-series in challenging conditions

Background

Extracorporeal membrane oxygenation (ECMO) use in patients with active bleedings or traumatic injuries may be challenging because of the risk of refractory haemorrhage related to systemic anticoagulation (SA). Technological advancements, especially heparin coated circuits, allowed ECMO application with a mild or no anticoagulation regimen in some circumstances. We herein report a limited case-series of ECMO application without anticoagulation.

Methods

ECMO without SA was established in 6 patients. Four of them received veno-arterial mode. Full heparin antagonization with protamine was provided in 3 post-cardiotomy cases. Tip-to-tip heparin-coated ECMO circuit was used in 4 patients, whereas heparin-coated tubing and no heparin-coated cannulas were applied for the remaining subjects.

Results

Mean duration of support and pump flow were 10±4 hours and 3.0±0.7 litres respectively. No ECMO related complication or oxygenator failure occurred, nor was clotting of the circuit observed at inspection. All patients were weaned from ECMO and half of them survived and were discharged.

Conclusions

Short ECMO duration without anticoagulation was feasible and provided effective cardiopulmonary support in patients with active bleeding or high hemorrhagic risk. Further investigations are needed to evaluate its benefits or limitations for a protracted time, in a wider range of clinical conditions and in larger patient populations.

Extracorporeal membrane oxygenation without therapeutic anticoagulation in adults: A systematic review of the current literature

Extracorporeal membrane oxygenation is essential for the treatment of refractory cardiopulmonary failure. Its use may be complicated by worse haemorrhagic complications exacerbated by extracorporeal membrane oxygenation–related therapeutic anticoagulation. Progressive technological advancements have made extracorporeal membrane oxygenation components less thrombogenic, potentially allowing its application with temporary avoidance of systemic anticoagulants. A systematic review of all the available experiences, reporting the use of extracorporeal membrane oxygenation without systemic anticoagulation in the published literature was performed. Only patient series were included, irrespective of the clinical indication. The survival, extracorporeal membrane oxygenation system–related dysfunction and complications rates, as well as in-hospital outcome, were analysed. Six studies were selected for the analysis. Veno-arterial extracorporeal membrane oxygenation was used in 84% of patients, while veno-venous extracorporeal membrane oxygenation was applied in the remaining cases. Anticoagulation was avoided because of the high risk of bleeding after cardiac surgery (64%), active major bleeding (23%) or presence of severe traumatic injury (9%). Duration of support ranged from 0.3 to 1128 h. Heparin was antagonized by protamine in all the post-cardiotomy cases. Successfully extracorporeal membrane oxygenation weaning was achieved in 74% of the treated cases, with a hospital discharge of 58% of patients. Rates of extracorporeal membrane oxygenation malfunctioning due to clot formation and blood transfusion requirement varied remarkably in the published series. Extracorporeal membrane oxygenation without systemic anticoagulation appears feasible in selected circumstances. Further investigations are warranted to elucidate actual aspects regarding extracorporeal membrane oxygenation system performance, related adverse events and benefits associated with this management.

Venoarterial extracorporeal membrane oxygenation use in staged combined heart-kidney transplant

Outside of heart and lung transplantation, only few cases have been reported describing venoarterial extracorporeal membrane oxygenation (VA-ECMO) use in solid organ transplantation. We present a case of a staged combined heart-kidney transplant in which VA-ECMO was utilized after a complicated orthotopic heart transplantation to successfully complete the subsequent renal transplantation.

Extracorporeal membrane oxygenation after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

Pulmonary endarterectomy (PEA) is the treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH) but can result in respiratory and cardiac complications that may require extracorporeal membrane oxygenation (ECMO). We reviewed our experience with ECMO in patients undergoing PEA.

METHODS AND RESULTS

Between January 2012 and August 2015, 35 patients underwent PEA for CTEPH. In all, four patients (11%) required veno-arterial (V-A) ECMO support due to severe cardiac and respiratory failure, including severe reperfusion pulmonary edema and persistent pulmonary hypertension. No significant differences in preoperative characteristics were found between patients who required ECMO and those who did not require ECMO. ECMO support was associated with a significantly higher incidence of postoperative respiratory complications, a longer intensive care unit stay, increased in-hospital mortality, residual pulmonary hypertension, and postoperative balloon pulmonary angioplasty (BPA). The postoperative mean pulmonary artery pressure and pulmonary vascular resistance were significantly higher in patients requiring ECMO. All patients requiring ECMO were successfully weaned off ECMO support (100%), and three of them were discharged from the hospital alive (75%).

CONCLUSIONS

Patients with CTEPH may benefit from ECMO after PEA for cardiac and respiratory complications. A prompt decision to use V-A ECMO is critical for a successful outcome in these patients.

Role and management of extracorporeal life support after surgery of chronic thromboembolic pulmonary hypertension

Background

Pulmonary endarterectomy (PEA) is a surgical intervention reserved for patients with chronic thromboembolic pulmonary hypertension (CTEPH). In some cases, temporary circulatory support [extracorporeal life support (ECLS)] is required after PEA. Rates of ECLS requirement varies between centers. Reasons for institution of ECLS include respiratory failure, cardiac failure (or both respiratory and cardiac failure), bleeding, and reperfusion edema. This article reviews the experience of ECLS after PEA from the current literature, as well as our own institution's experience as a CTEPH multidisciplinary center.

Methods

A literature review was conducted along with a retrospective chart review from 15 years of our PEA program.

Results

The literature demonstrates many different approaches are used for mechanically supporting patients who develop complications after PEA. Variations in approach stem from differing indications such as, respiratory failure rather than hemodynamic compromise (or vice versa), time of implantation (immediately in operating room or delayed after surgery) and many other causes. In our center, 12.3% (19/154) of patients need ECLS with extracorporeal membrane oxygenator (ECMO) after PEA procedure. Implantation was mainly in the operating room before or immediately after weaning from cardiopulmonary bypass and mostly peripheral cannulation was used. ECMO lasted an average of 11±8 days. And 52.6% (10 of 19 patients) of patients were weaned from ECLS and of this, 70% (7 of 10 patients) were discharged.

Conclusions

In some cases of PEA, ECLS is needed post-operatively. Expert teams should consider this possibility pre-operatively based on predisposing characteristics. The need for ECMO shouldn't be "di per se" a contraindication to surgery but might be considered in the surgical risk estimation. The ideal setup is not fixed and depends on the center's practices as well as indication. Even though complications do occur with ECMO, in general, results are good, being a bridge to further recovery of pulmonary hypertension (PH) or also to transplantation.