Cardiopulmonary Bypass and Extracorporeal Life Support for Emergent Intraoperative Thoracic Situations

Extracorporeal Membrane Oxygenation-Supported Patient Outcome Undergoing Transcatheter Aortic Valve Replacement

The efficacy and safety of extracorporeal membrane oxygenation (ECMO) support during transcatheter aortic valve replacement (TAVR) remains unknown. We conducted a meta-analysis to compare benefit and risk of ECMO in TAVR patients. Bibliographic databases were searched from inception to January 1, 2024. Included studies involved patients ≥18 years old undergoing TAVR and using ECMO emergently or prophylactically. Mortality and procedure success were primary outcomes. Peri- or postoperative complications were the secondary outcomes. We identified 11 observational studies, including 2,275 participants (415 ECMO and 1,860 non-ECMO). The unadjusted mortality risk in ECMO-supported patient was higher than non-ECMO patients (odds ratio [OR] 1.73). The mortality unadjusted risk remained high (OR 3.89) and statistically significant for prophylactic ECMO. Prophylactic ECMO had lower mortality risk compared with emergent ECMO (OR 0.17). Extracorporeal membrane oxygenation-supported patients had lower procedural success rate (OR 0.10). Extracorporeal membrane oxygenation patients undergoing TAVR had significantly increased risk of bleeding (OR 3.32), renal failure (OR 2.38), postoperative myocardial infarction (OR 1.89), and stroke (OR 2.32) compared with non-ECMO patients. Clinical results are not improved by ECMO support in patients with high-risk TAVR. Prophylactic ECMO outperforms emergent. Overall, ECMO support increases mortality and postoperative complications. Transcatheter aortic valve replacement outcomes may improve with prophylactic ECMO in high-risk situations.

Pediatric Lung Transplantation for Pulmonary Vascular Diseases: Recent Advances and Challenges

Pediatric lung transplantation for pulmonary vascular diseases has seen notable advancements and trends. Medical therapies, surgical options, and bridging techniques like extracorporeal membrane oxygenation and different forms of transplants have expanded treatment possibilities. Current challenges include ensuring patient adherence to post-transplant therapies, addressing complications like primary graft dysfunction and rejection, and conducting further research in less common conditions like pulmonary veno-occlusive disease and pulmonary vein stenosis. In this review article, the authors will explore the advancements, emerging trends, and persistent challenges in pediatric lung transplantation for pulmonary vascular diseases.

Managing pulmonary arterial hypertension: how to select and facilitate successful transplantation

PURPOSE OF REVIEW

Despite improvements in available medical therapies, pulmonary arterial hypertension (PAH) remains a progressive, ultimately fatal disorder. Lung transplantation is a viable treatment option for PAH patients with advanced disease.

RECENT FINDINGS

Recent guidelines from the International Society of Heart and Lung Transplantation (ISHLT) have updated recommendations regarding time of referral and listing for lung transplantation in PAH. The new guidelines emphasize earlier referral for transplant evaluation to ensure adequate time for proper evaluation and listing. They also incorporate objective risk stratification criteria to assist in decision-making regarding timing of referral and listing. With regards to the transplant procedure, bilateral lung transplantation has largely supplanted heart-lung transplantation as the procedure of choice for transplantation for advanced PAH. Exceptions to this include patients with PAH because of congenital heart disease and those with concurrent LV dysfunction. Use of mechanical support via venoarterial ECMO initiated before transplantation and continued into the early postoperative period is emerging as a standard of care and may help to reduce early posttransplant mortality in this population. There has been increased recognition of the importance of WHO Group 3 pulmonary hypertension. Many of the lessons learned from PAH may be applied when transplanting patients with severe WHO Group 3 pulmonary hypertension.

SUMMARY

Patients with PAH present unique challenges with regards to transplantation that require a therapeutic approach distinct from other lung disorders. Lung transplantations for PAH are high-risk endeavors best performed at centers with expertise in management of both PAH and extracorporeal support.

Intraoperative support during lung transplantation

The role of intraoperative mechanical support during lung transplantation (LTx) is essential to provide a safe hemodynamic and ventilatory status during critical intraoperative events. This hemodynamic and ventilatory stability is vital to minimize the odds of suboptimal outcomes, especially considering that, due to the scarcity of donors and the fact that more and more patients with significant comorbidities are being considered for this therapy, a more aggressive approach is often needed by the transplant centers. Hence, the attenuation of any potential injury that can happen during this complex event is paramount. While a thorough assessment of the donor and optimization of postoperative care is pursued, certainly protective intraoperative management would also contribute to better outcomes. Understanding each patient’s underlying anatomy and cardiopulmonary physiology, associated with awareness of critical events during a complicated procedure like LTx, is essential for a precise indication and safe use of support. Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation (VA ECMO) have been the most common approaches used, with the latter gaining popularity more recently and we have used VA ECMO exclusively for the last decade. New technologies certainly contributed to more liberal use of VA ECMO intraoperatively, enabling a protecting and physiologic environment for the newly implanted grafts. In this setting, potential prophylactic use for lung protection during a critical period is also considered.

[Extracorporeal Lung Support in Thoracic Surgery: Basics and Pathophysiology]

Extracorporeal lung support (ECLS) is of increasing importance in general thoracic surgery. Different modes of ECLS may be applied in several situations throughout the perioperative phase and are adapted to the individual patient's needs and the planned surgical procedures. ECLS is not a static procedure and should be always evaluated according to the present condition of the patient. Therefore, it is essential to understand the pathophysiology of the disease and the different ECLS modes, as well as the different cannulation options, in order to be able to use the different escalation and de-escalation techniques in accordance with the clinical situation.

Cardiopulmonary Bypass in Non-Cardiac Surgery

BACKGROUND

Cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO) are used to facilitate circulatory support in standard cardiac surgery and emergency intervention, but CPB and ECMO are not used routinely in non-cardiac surgery involving the thorax and major vessels. The primary aim of this study was to identify the type of non-cardiac procedures and bypass used in our institution and review the patient outcomes including perioperative and bypass complications.

METHODS

A retrospective study was performed within the Royal Adelaide Hospital Cardiothoracic Surgery Unit (CTSU) that examined all operations between 2006 and 2014. There were 1,816 non-cardiac cases, of these nine used CPB or ECMO. Cases excluded from the study were those that required cardiac surgical management with the use of CPB or ECMO.

RESULTS

Twelve (12) non-cardiac surgery cases were reviewed, with three, and nine cases, respectively, using ECMO and CPB standby or support. The non-cardiac surgical procedures included eight thoracic cases, two renal cases and two tracheal cases. Of the thoracic cases, five were elective, two were bailout and one was an emergency. Both renal cases were bailout (with one as major vessel support and one as standby). Both tracheal cases were bailout (one as an emergency and one as standby). Intraoperative complications included severe haemorrhage in three cases. General postoperative complications included increased analgesia requirement, atelectasis, fever; and prolonged ECMO support and ICU stay which occurred in seven cases. No direct complications of CPB or ECMO are reported. Four of the 12 cases that encompassed thoracic, renal and tracheal surgery are discussed in detail.

CONCLUSIONS

Our review of 12 cases managed under the CTSU has shown that extracorporeal circulatory support can be used in a range of thoracic, renal and tracheal surgery. These surgical procedures have involved the management of haemodynamically unstable patients. Patient outcomes have been encouraging with few complications. With further research including the use of a larger sample size and control groups, more definitive conclusions could be made on the benefit of CPB and ECMO to patients in non-cardiac surgery.

Principles and indications of extracorporeal life support in general thoracic surgery

The role of extracorporeal life support (ECLS) has expanded rapidly over the past 15 years to become an important tool in advanced general thoracic surgery practice. Intra-operative and in some cases continued post-operative ECLS is redefining the scope of complex surgical care. ECLS encompasses a spectrum of temporary mechanical support that may remove CO₂, oxygenate or provide hemodynamic support or a combination thereof. The most common modalities used in general thoracic surgery include extracorporeal membrane oxygenation (ECMO), interventional lung assist device (iLA^® Novalung^®, Heilbronn, Germany), and extracorporeal CO₂ removal (ECCO₂R). The ECMO and Novalung^® devices can be used in different modes for the short term or long-term support depending on the situation. In this review, the principles and current applications of ECLS in general thoracic surgery are presented.

Advanced pulmonary arterial hypertension: mechanical support and lung transplantation

The development of targeted therapies has transformed the outlook for patients with pulmonary arterial hypertension (PAH); however, some patients fail to achieve an adequate clinical response despite receiving maximal treatment. For these patients, lung transplantation remains an important therapeutic option, and recommendations for transplantation are included in the current European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of pulmonary hypertension. Although lung transplantation is not without risk, overall long-term survival rates are good and substantial improvements in quality of life have been reported for lung transplant recipients. In this review, we describe the important considerations prior to, during and after transplantation, including the role of mechanical support, in patients with advanced PAH.

Lung transplantation and mechanical support play key therapeutic roles in patients with advanced PAHhttp://ow.ly/mqfG30gMcMd

Outcomes of perioperative extracorporeal membrane oxygenation use in patients undergoing lung transplantation

Background

The aim of this single-center study is to review the transplant outcomes of patients receiving lung transplantation (LTx) using intraoperative extracorporeal membrane oxygenation (ECMO) according to the perioperative use of ECMO.

Methods

We retrospectively reviewed the transplant outcomes of 107 consecutive patients who underwent LTx using intraoperative ECMO between March 2013 and August 2016 at Severance Hospital of Yonsei University (Seoul, Korea).

Results

Patients were divided into the following three groups according to the use of perioperative ECMO: only intraoperative ECMO (n=47) or extended post-operative ECMO but no bridging and no postoperative ECMO re-implantation (secondary ECMO; n=28) as Group A (n=75); bridging ECMO without secondary ECMO (n=14) as Group B; and secondary ECMO with (n=7) or without (n=11) bridging as Group C. Baseline demographics were comparable among the three groups. The mean duration of preoperative ECMO bridging was 16.4±15.6 (n=21). After a median of 17.7 months (range, 3.1-40.9 months) for survivors, the one year overall survival (OS) rates after LTx for the three groups were 76.3%±5.2% for Group A, 59.9%±14.3% for Group B, and 14.0%±9.0% for Group C (P<0.0001). The secondary ECMO (Group C) was established a mean of 7.9±5.3 days after LTx. The main cause of secondary ECMO was acute respiratory failure from pneumonia, and the main cause of death was infection-related events.

Conclusions

Our data suggests that the use of perioperative ECMO, including its extended postoperative use during LTx, is feasible and has favorable outcomes. However, as shown by the poor survival outcome after secondary ECMO, the development of solid strategy to reduce the need for secondary ECMO implantation after LTx seems important.