Extracorporeal circulatory support for lung transplantation: institutional experience

Intraoperative extracorporeal membrane oxygenation for lung transplantation in cystic fibrosis patients: Predictors and impact on outcome

BACKGROUND

Predictors and outcomes of intraoperative extracorporeal membrane oxygenation (ECMO) during lung transplantation (LUTX) for cystic fibrosis (CF) are unknown.

METHODS

We retrospectively collected the clinical data at enlistment of the CF patients who underwent double LUTX from January 2013 to December 2018 at an Italian tertiary referral center. We compared blood transfusions, incidence of primary graft dysfunction (PGD), duration of mechanical ventilation, intensive care unit (ICU) length of stay (LOS), hospital LOS and survival of ECMO and non-ECMO patients. Chi-square, Kruskal-Wallis, and log-rank tests were used.

RESULTS

Twenty-eight (40%) of the 70 included patients needed intraoperative central veno-arterial ECMO with postoperative veno-venous prolongation in 6 subjects. Lower right ventricle ejection fraction (p = 0.013, OR 0.92(0.86-0.98)), higher oxygen requirement (p = 0.026, OR 1.39(1.01-1.90)), lower body surface area (p = 0.044, OR 0.05(0.00-1.03)), and CF-related diabetes (p = 0.044, OR 2.81(1.03-7.66)) were associated with intraoperative ECMO. Compared to non-ECMO patients, ECMO patients needed almost fivefold intraoperative transfusion (2227 mL vs. 570 mL, p<0.001) and had PGD grade > 0 at 72 h more frequently (16/57% vs. 12/28%, p = 0.017, OR 3.33(1.22-9.09)). Mechanical ventilation, ICU LOS and hospital LOS were significantly longer in ECMO patients. Survival at follow-up (651(326-1277) days) of ECMO and non-ECMO patients was 78% vs. 83%, respectively (OR 0.73 (0.21-2.46), p = 0.616, log-rank test p = 0.498).

CONCLUSION

Pre-operative risk assessment and clinical planning should be done according to the predictors above. While undeniably useful as a life-saving procedure, ECMO during LUTX for CF is associated with worsened short-term outcomes. ECMO should be implemented weighing its risk and benefits.

Pulmonary Hypertension and Polycythemia Secondary to Pulmonary Alveolar Microlithiasis Treated with Sequential Bilateral Lung Transplant: A Case Study and Literature Review

Patient: Male, 49

Final Diagnosis: Pulmonary alveolar microlithiasis

Symptoms: Coughing • shortness of breath

Medication: —

Clinical Procedure: —

Specialty: Surgery

Extracorporeal Circulation During Lung Transplantation Procedures: A Meta-Analysis

Extracorporeal circulation (ECC) is an invaluable tool in lung transplantation (lutx). More than the past years, an increasing number of centers changed their standard for intraoperative ECC from cardiopulmonary bypass (CPB) to extracorporeal membrane oxygenation (ECMO) - with differing results. This meta-analysis reviews the existing evidence. An online literature research on Medline, Embase, and PubMed has been performed. Two persons independently judged the papers using the ACROBAT-NRSI tool of the Cochrane collaboration. Meta-analyses and meta-regressions were used to determine whether veno-arterial ECMO (VA-ECMO) resulted in better outcomes compared with CPB. Six papers - all observational studies without randomization - were included in the analysis. All were considered to have serious bias caused by heparinization as co-intervention. Forest plots showed a beneficial trend of ECMO regarding blood transfusions (packed red blood cells (RBCs) with an average mean difference of -0.46 units [95% CI = -3.72, 2.80], fresh-frozen plasma with an average mean difference of -0.65 units [95% CI = -1.56, 0.25], platelets with an average mean difference of -1.72 units [95% CI = -3.67, 0.23]). Duration of ventilator support with an average mean difference of -2.86 days [95% CI = -11.43, 5.71] and intensive care unit (ICU) length of stay with an average mean difference of -4.79 days [95% CI = -8.17, -1.41] were shorter in ECMO patients. Extracorporeal membrane oxygenation treatment tended to be superior regarding 3 month mortality (odds ratio = 0.46, 95% CI = 0.21-1.02) and 1 year mortality (odds ratio = 0.65, 95% CI = 0.37-1.13). However, only the ICU length of stay reached statistical significance. Meta-regression analyses showed that heterogeneity across studies (sex, year of ECMO implementation, and underlying disease) influenced differences. These data indicate a benefit of the intraoperative use of ECMO as compared with CPB during lung transplant procedures regarding short-term outcome (ICU stay). There was no statistically significant effect regarding blood transfusion needs or long-term outcome. The superiority of ECMO in lutx patients remains to be determined in larger multi-center randomized trials.

A rare indication for lung transplantation - pulmonary alveolar microlithiasis: institutional experience of five consecutive cases

BACKGROUND

Pulmonary alveolar microlithiasis (PAM) is a rare lung disease caused by calcifications within the alveolar space. The only known effective treatment for an end-stage PAM is lung transplantation (LuTX).

METHODS

We performed a retrospective chart review of all individuals that underwent lung transplantation at our center between 1989 and 2013. Five consecutive patients with PAM were identified.

RESULTS

Four females and one male with a mean age of 46.3 yr were identified. Extracorporeal membrane oxygenation (ECMO) support was required intraoperatively in four cases and post-operatively in one case. Mean post-operative intubation time was 3.3 (range, 2-5) d and mean intensive care unit (ICU) stay was 8.3 (range, 4-12) d. No intraoperative complications were observed. One early patient (operated in 1995) underwent acute re-transplantation on the second post-operative day (POD) and died from sepsis on the 11 POD. In one patient reperfusion edema was observed requiring a prolonged weaning process. No other severe perioperative complications were observed. Four of five patients are currently still alive with normal follow-up parameters. No recurrence of PAM was observed.

CONCLUSIONS

Lung transplantation is a feasible therapy option in patients with end-stage PAM showing good post-operative results comparable to other indications for LuTX.

Mechanical circulatory support in lung transplantation: Cardiopulmonary bypass, extracorporeal life support, and ex-vivo lung perfusion

Lung transplant is the standard of care for patients with end-stage lung disease refractory to medical management. There is currently a critical organ shortage for lung transplantation with only 17% of offered organs being transplanted. Of those patients receiving a lung transplant, up to 25% will develop primary graft dysfunction, which is associated with an 8-fold increase in 30-d mortality. There are numerous mechanical lung assistance modalities that may be employed to help combat these challenges. We will discuss the use of mechanical lung assistance during lung transplantation, as a bridge to transplant, as a treatment for primary graft dysfunction, and finally as a means to remodel and evaluate organs deemed unsuitable for transplant, thus increasing the donor pool, improving survival to transplant, and improving overall patient survival.

Low-Flow Veno-Venous Extracorporeal CO2 Removal: First Clinical Experience in Lung Transplant Recipients

Background

Low-flow extracorporeal CO2 removal devices are easy to setup and manage and may provide valuable ventilation support.

Methods

We employed a new device (ProLUNG) recently introduced into the clinical arsenal that exploits a simple hemoperfusion technique sustained by blood flows lower than 500 ml/min to remove CO2 from the venous blood. It was used as an adjunctive support to mechanical ventilation during and after four lung transplantations in our center.

Results

Two patients with cystic fibrosis, one with pulmonary fibrosis, and one with emphysema were included. They underwent lung transplantation and presented hypercapnia and respiratory acidosis before, during, or after the surgical procedure. After 1 h of treatment with the ProLUNG circuit, all patients showed reduced CO2 levels and increased pH; these variables remained stable until the end of treatment.

Conclusions

Our data suggest that this new device is effective in removing CO2 and stabilizing the pH.

Extracorporeal membrane oxygenation as a bridge to lung transplantation in the United States: an evolving strategy in the management of rapidly advancing pulmonary disease

OBJECTIVE

Improvements in technology have led to a resurgence in the use of extracorporeal membrane oxygenation as a bridge to lung transplantation. By using a national registry, we sought to evaluate how short-term survival has evolved using this strategy.

METHODS

With the use of the United Network for Organ Sharing database, we analyzed data from 12,458 adults who underwent lung transplantation between 2000 and 2011. Patients were categorized into 2 cohorts: 119 patients who were bridged to transplantation using extracorporeal membrane oxygenation and 12,339 patients who were not. The study period was divided into four 3-year intervals: 2000 to 2002, 2003 to 2005, 2006 to 2008, and 2009 to 2011. With Kaplan-Meier analysis, 1-year survival was compared for the 2 cohorts of patients in each of the time periods. A propensity score-adjusted Cox regression model was used to estimate the risk of 1-year mortality.

RESULTS

Of the total number of recipients, 4 (3.4%) were bridged between 2000 and 2002, 17 (14.3%) were bridged between 2003 and 2005, 31 (26.1%) were bridged between 2006 and 2008, and 67 were bridged (56.3%) between 2009 and 2011. Recipients bridged using extracorporeal membrane oxygenation were more likely to be younger and diabetic and to have higher serum creatinine and bilirubin levels. The 1-year survival for those bridged with extracorporeal membrane oxygenation was significantly lower in subsequent periods: 25.0% versus 81.0% (2000-2002), 47.1% versus 84.2% (2006-2008), and 74.4% versus 85.7% (2009-2011). However, this survival progressively increased with each period, as did the number of patients bridged using extracorporeal membrane oxygenation.

CONCLUSIONS

Short-term survival with the use of extracorporeal membrane oxygenation as a bridge to lung transplantation has significantly improved over the past few years.

Lung transplantation for cystic fibrosis: outcome of 101 single-center consecutive patients

Bilateral sequential lung transplantation (BSLT) is nowadays considered a valid therapeutic option for patients with end stage cystic fibrosis. We report our experience with 104 BSLTs in 101 patients. The overall survivals at 1, 3, 5, 10 years were 79%, 65%, 58%, and 42%, respectively. Perioperative mortality was 14.8% (n = 15). The leading causes of perioperative mortality were primary graft dysfunction and sepsis. Three patients were retransplanted owing to obliterative bronchiolitis. In 70 cases (69%), patients displayed ≥ 1 additional risk factors: previous lung resections, colonization by Burkholderia cepacia, diabetes, pneumothorax, or noninvasive ventilatory support. The mean preoperative 1-second forced expiratory volume of 0.69 ± 0.2 L (22%) increased to 85% at 1 year after the operation. The mean time on the waiting list was 12 ± 5 months. The 5 patients treated with extracorporeal membrane oxygenation before urgent transplantation were operated after 3, 5, 6, 30, and 3 days respectively. During the procedure, cardiopulmonary bypass was required in 33 patients (32%). Lung transplantation represents a unique opportunity to ameliorate the quality and improve the survival of patients affected by cystic fibrosis. Timing of referral and patient selection remain crucial for success.

Lung transplantation for cystic fibrosis after thoracic surgical procedures

During their life, cystic fibrosis (CF) patients may require thoracic surgical procedures for a number of reasons before undergoing lung transplantation. In the past, this has been considered to be a contraindication to lung transplantation. However, a meticulous surgical technique and careful intraoperative management allows one to perform the transplantation safely. Herein we have reported our experience with CF patients undergoing lung transplantation after previous surgical treatment for pneumothorax or bronchiectasis.