Lung transplantation (LT) is a vital intervention for end-stage pulmonary diseases but is associated with high perioperative morbidity and mortality. This review analyzes the efficacy and safety of intraoperative support strategies, including veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and cardiopulmonary bypass (CPB), compared to traditional OffPump techniques. The aim is to guide optimal intraoperative management and improve patient outcomes.
The systematic review incorporated 27 studies involving 6113 patients, examining outcomes such as the need for blood product transfusions, mechanical ventilation duration, ICU length of stay, surgical duration, and mortality. Data were synthesized using Bayesian network meta-analysis methods.
Key Findings:
- Off Pump Superiority: OffPump strategies outperformed ECMO and CPB across nearly all outcomes. Patients undergoing OffPump LT experienced lower blood product requirements, shorter durations of invasive mechanical ventilation (IMV), reduced ICU stays, and better survival rates. These advantages highlight the benefits of avoiding extracorporeal support when feasible.
- Comparison of Extracorporeal Supports: Between V-A ECMO and CPB, ECMO offered superior outcomes, such as shorter IMV durations and reduced ICU stays. Despite these advantages, ECMO usage was associated with higher blood product requirements than OffPump strategies, although less than CPB.
- Mortality Analysis: OffPump surgery had the lowest mortality rates among all strategies. While ECMO showed improved survival rates compared to CPB, it still lagged behind OffPump methods.
- Demographic and Clinical Influences:
- Age: Older patients had prolonged ICU stays and higher surgical complexity, potentially due to comorbidities.
- Gender: Male patients required more blood transfusions and had longer surgeries compared to females.
- BMI: Obesity negatively influenced ICU length of stay, postoperative ECMO use, and mortality rates, reflecting challenges in managing overweight patients during LT.
- Emerging Trends: Over the last decade, evolving ECMO techniques and protocols have reduced transfusion needs and improved outcomes compared to CPB. However, heterogeneity in practices across regions and institutions remains a barrier to standardization.
Implications:
The findings suggest that avoiding extracorporeal support when feasible is optimal, as OffPump approaches consistently demonstrated superior outcomes. For cases requiring mechanical support, ECMO offers a better alternative to CPB. The study emphasizes the need for tailored intraoperative strategies, considering patient factors such as age and BMI to minimize risks.
Limitations:
This analysis was constrained by the predominance of observational studies, introducing biases and heterogeneity. Variability in institutional practices and evolving ECMO protocols also complicates comparisons. Future randomized controlled trials are necessary to validate these findings and address critical gaps, such as the long-term impact of ECMO on primary graft dysfunction (PGD).
Conclusion:
Off Pump strategies are recommended as the preferred approach for LT whenever feasible due to their superior outcomes. Among extracorporeal supports, V-A ECMO should be prioritized over CPB for complex cases. Further research is required to refine these strategies, optimize ECMO use, and standardize intraoperative protocols to improve LT outcomes.
