Cardiopulmonary bypass for bilateral sequential lung transplantation in patients with chronic obstructive pulmonary disease without adverse effect on lung function or clinical outcome

Which strategy is better for lung transplantation: Cardiopulmonary bypass or extracorporeal membrane oxygenation?

Background: In lung transplantation surgery, extracorporeal life support (ECLS) is essential for safety. Various support methods, including cardiopulmonary bypass (CPB) and off-pump techniques, are used, with extracorporeal membrane oxygenation (ECMO) gaining prominence. However, consensus on the best support strategy is lacking.Purpose: This article reviews risks, benefits, and outcomes of different support strategies in lung transplantation. By consolidating knowledge, it aims to clarify selecting the most appropriate ECLS modality.Research Design: A comprehensive literature review examined CPB, off-pump techniques, and ECMO outcomes in lung transplantation, including surgical results and complications.Study Sample: Studies, including clinical trials and observational research, focused on ECLS in lung transplantation, both retrospective and prospective, providing a broad evidence base.Data Collection and/or Analysis: Selected studies were analyzed for surgical outcomes, complications, and survival rates associated with CPB, off-pump techniques, and ECMO to assess safety and effectiveness.Results: Off-pump techniques are preferred, with ECMO increasingly vital as a bridge to transplant, overshadowing CPB. However, ECMO entails hidden risks and higher costs. While safer than CPB, optimizing ECMO postoperative use and monitoring is crucial for success.Conclusions: Off-pump techniques are standard, but ECMO's role is expanding. Despite advantages, careful ECMO management is crucial due to hidden risks and costs. Future research should focus on refining ECMO use and monitoring to improve outcomes, emphasizing individualized approaches for LT recipients.

Current and future role of double-lung transplantation for bilateral lung cancer

Technological advances have progressively enhanced the survival rate of lung transplant recipients and expanded its indications for various diseases, including the recent coronavirus disease 2019 (COVID-19). However, according to the International Society for Heart and Lung Transplantation, lung cancer constituted a mere 0.1% of the indications for lung transplantation over the past two decades. This statistic has remained stagnant, and numerous lung cancer patients continue to be excluded from lung transplantation candidacy. Contrary to the general exclusion of lung cancer patients from transplantation, the post-transplant survival rate for these patients is not inferior to that of patients with non-cancerous diseases. Furthermore, lung transplantation may offer curative treatment for patients with bilateral lung cancer whose respiratory insufficiency has advanced independently of cancer progression. This review aims to elucidate and examine the role of double lung transplantation (DLT) in bilateral lung cancer. We summarize the established indications for lung transplantation, appropriate histologic or molecular subtypes of lung cancer for transplantation, technical advances to minimize recurrence, post-DLT survival outcomes for lung cancer patients, and related translational research. We suggest that although DLT for bilateral lung cancer presents challenges, it may be considered a potential treatment option in select circumstances.

Primary Graft Dysfunction

Primary graft dysfunction (PGD) is a form of acute lung injury after transplantation characterized by hypoxemia and the development of alveolar infiltrates on chest radiograph that occurs within 72 hours of reperfusion. PGD is among the most common early complications following lung transplantation and significantly contributes to increased short-term morbidity and mortality. In addition, severe PGD has been associated with higher 90-day and 1-year mortality rates compared with absent or less severe PGD and is a significant risk factor for the subsequent development of chronic lung allograft dysfunction. The International Society for Heart and Lung Transplantation released updated consensus guidelines in 2017, defining grade 3 PGD, the most severe form, by the presence of alveolar infiltrates and a ratio of PaO₂:FiO₂ less than 200. Multiple donor-related, recipient-related, and perioperative risk factors for PGD have been identified, many of which are potentially modifiable. Consistently identified risk factors include donor tobacco and alcohol use; increased recipient body mass index; recipient history of pulmonary hypertension, sarcoidosis, or pulmonary fibrosis; single lung transplantation; and use of cardiopulmonary bypass, among others. Several cellular pathways have been implicated in the pathogenesis of PGD, thus presenting several possible therapeutic targets for preventing and treating PGD. Notably, use of ex vivo lung perfusion (EVLP) has become more widespread and offers a potential platform to safely investigate novel PGD treatments while expanding the lung donor pool. Even in the presence of significantly prolonged ischemic times, EVLP has not been associated with an increased risk for PGD.

A comparison of cardiopulmonary bypass versus extracorporeal membrane oxygenation: Does intraoperative circulatory support strategy affect outcomes in pediatric lung transplantation?

OBJECTIVE

Data on adult lung transplantation suggest perioperative benefits of intraoperative extracorporeal membrane oxygenation (ECMO) compared to cardiopulmonary bypass (CPB). Information regarding their pediatric counterparts, however, is limited. This study compares outcomes of intraoperative ECMO versus CPB in pediatric lung transplantation.

METHODS

We reviewed all pediatric lung transplants at our institution from 2014 to 2019 and compared those supported intraoperatively on ECMO (n = 13) versus CPB (n = 22), plus a conditional analysis excluding re-transplantations (ECMO [n = 13] versus CPB [n = 20]). We evaluated survival, surgical times, intraoperative transfusions, postoperative support, complications, and duration of hospitalization.

RESULTS

Total time on ECMO support was significantly less than that of CPB support (P = .018). Intraoperatively, the ECMO group required fewer transfusions of fresh-frozen plasma (8.9 [5.8-22.3] vs 16.6 [11.4-39.0] mL/kg, P = .049) and platelets (4.2 [0.0-6.7] vs 8.0 [3.5-14.0] mL/kg, P = .049). When excluding re-transplantations, patients on ECMO required fewer packed red blood cells intraoperatively (12.6 [2.1-30.7] vs 28.2 [14.0-54.0] mL/kg, P = .048). There were no differences in postoperative support requirements, complications, or mortality at one, six, and twelve months.

CONCLUSIONS

Intraoperative ECMO support during pediatric lung transplantation appears to decrease intraoperative transfusion requirements when compared to CPB. Data from additional institutions may strengthen these observations.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Lung transplantation via cardiopulmonary bypass: excellent survival outcomes from extended criteria donors

OBJECTIVES

The role of intraoperative cardiopulmonary bypass (CPB) in lung transplant (LTx) surgery is controversial. CPB enables slow pulmonary reperfusion and initial ventilation with low oxygen concentrations, both theoretically protective of transplanted lungs. In this study, we explored clinical outcomes following extended criteria donor LTx surgery implementing a thoroughly protective allograft reperfusion strategy using CPB.

METHODS

Thirty-nine consecutive adult patients who underwent bilateral LTx with elective CPB and protective allograft reperfusion were reviewed. Bilaterally implanted lungs were reperfused simultaneously, via slow CPB flow reduction and initial ventilation with 21% oxygen and nitric oxide, followed by a brief modified ultrafiltration. During weaning from CPB, mean pulmonary arterial pressure was strictly maintained at 10-15 mmHg by controlling CPB and pulmonary flow. The clinical outcomes in 23 patients who received lungs from extended criteria donors (ECD group) were elucidated and compared to 16 patients undergoing LTx from standard criteria donors (SCD group).

RESULTS

No life-threatening deterioration was observed to graft functionality during the first 72 h after LTx in the ECD group; however, only one patient required post-transplant extracorporeal membrane oxygenation. In three of 23 ECD LTx patients (12%), surgical revision for bleeding was required. Survival outcomes for the ECD group were favorable, with 100% survival at 6-months, 87.0% at 1-year, and 80.7% at 5-years. Outcomes in the ECD group were comparable to those in the SCD group.

CONCLUSIONS

Despite a certain extent of risk associated with full-dose heparinization, use of CPB does not undermine survival outcomes after ECD LTx surgery if protective allograft reperfusion is securely performed.

Single- and Double-Lung Transplantation: Results of an Initial Experience of 39 Cases in Ceará (Northeast Brazil)

INTRODUCTION

The lung transplantation (LTx) program began in Ceará in 2011 and the first LTx was performed on June 11, 2011. The aim of this study was to present the initial results of the 6-year experience of our program.

METHODS

We retrospectively reviewed our experience on LTx from June 2011 to August 2017. Data on recipients and transoperative and postoperative outcomes were recorded in a database.

RESULTS

Twenty-two (56.4%) were single LTx, 15 (38.5%) were double, and 2 (5.1%) bilateral lobar. The mean age was 47.5 ± 15 years, and 26 (66.7%) were men. Twenty-eight (71.8%) had pulmonary fibrosis; 5 (12.8%) had pulmonary emphysema, 3 (7.7%) had bronchiectasis; 2 (5.1%) had pulmonary hypertension, and 1 (2.6%) had lymphangioleiomyomatosis. Complications occurred in 82% (32/39) and in-hospital mortality was 30.8% (single LTx = 27.8% and double LTx = 33.3%). The main complications were infection in 17 (43.5%) cases and primary graft dysfunction in 7 (17.9%). There was a significant improvement in pulmonary function in the first year of follow-up (forced expiratory volume pre-LTx = 37% ± 16% and 12 months post-LTx = 72% ± 22%, P = .001); and overall survival at 36 months was 59.0%, with no difference between single- and double-lung transplants.

CONCLUSIONS

Idiopathic pulmonary fibrosis was the most common underlying disease and single LTx was the most commonly performed operation. There was a high incidence of postoperative complications and in-hospital mortality, but the 36-month follow-up showed a marked improvement in lung function and a global survival similar to the literature.

Lung Transplantation in Cystic Fibrosis and the Impact of Extracorporeal Circulation

INTRODUCTION

Lung disease is the major cause of death among cystic fibrosis (CF) patients, affecting 80% of the population. The impact of extracorporeal circulation (ECC) during transplantation has not been fully clarified. This study aimed to evaluate the outcomes of lung transplantation for CF in a single center, and to assess the impact of ECC on survival.

METHODS

We performed a retrospective observational study of all trasplanted CF patients in a single center between 1992 and 2011. During this period, 64 lung transplantations for CF were performed.

RESULTS

Five- and 10-year survival of trasplanted patients was 56.7% and 41.3%, respectively. Pre-transplantation supplemental oxygen requirements and non-invasive mechanical ventilation (NIMV) do not seem to affect survival (P=.44 and P=.63, respectively). Five- and 10-year survival among patients who did not undergo ECC during transplantation was 75.69% and 49.06%, respectively, while in those did undergo ECC during the procedure, 5- and 10-year survival was 34.14% and 29.87%, respectively (P=.001). PaCO₂ is an independent risk factor for the need for ECC.

CONCLUSIONS

The survival rates of CF patients undergoing lung transplantation in our hospital are similar to those described in international registries. Survival is lower among patients receiving ECC during the procedure. PaCO₂ is a risk factor for the need for ECC during lung transplantation.

Primary Graft Dysfunction After Lung Transplantation

Primary graft dysfunction is a form of acute injury after lung transplantation that is associated with significant short- and long-term morbidity and mortality. Multiple mechanisms contribute to the pathogenesis of primary graft dysfunction, including ischemia reperfusion injury, epithelial cell death, endothelial cell dysfunction, innate immune activation, oxidative stress, and release of inflammatory cytokines and chemokines. This article reviews the epidemiology, pathogenesis, risk factors, prevention, and treatment of primary graft dysfunction.

Pathophysiology and classification of primary graft dysfunction after lung transplantation

The term primary graft dysfunction (PGD) incorporates a continuum of disease severity from moderate to severe acute lung injury (ALI) within 72 h of lung transplantation. It represents the most significant obstacle to achieving good early post-transplant outcomes, but is also associated with increased incidence of bronchiolitis obliterans syndrome (BOS) subsequently. PGD is characterised histologically by diffuse alveolar damage, but is graded on clinical grounds with a combination of PaO2/FiO2 (P/F) and the presence of radiographic infiltrates, with 0 being absence of disease and 3 being severe PGD. The aetiology is multifactorial but commonly results from severe ischaemia-reperfusion injury (IRI), with tissue-resident macrophages largely responsible for stimulating a secondary 'wave' of neutrophils and lymphocytes that produce severe and widespread tissue damage. Donor history, recipient health and operative factors may all potentially contribute to the likelihood of PGD development. Work that aims to minimise the incidence of PGD in ongoing, with techniques such as ex vivo perfusion of donor lungs showing promise both in research and in clinical studies. This review will summarise the current clinical status of PGD before going on to discuss its pathophysiology, current therapies available and future directions for clinical management of PGD.

Management of Pulmonary Hypertension in the Operating Room

Pulmonary artery hypertension is defined as persistent elevation of mean pulmonary artery pressure > 25 mm Hg with pulmonary capillary wedge pressure < 15 mm Hg or elevation of exercise mean pulmonary artery pressure > 35 mm Hg. Although mild pulmonary hypertension rarely impacts anesthetic management, severe pulmonary hypertension and exacerbation of moderate hypertension can lead to acute right ventricular failure and cardiogenic shock. Knowledge of anesthetic drug effects on the pulmonary circulation is essential for anesthesiologists. Intraoperative management should include prevention of exacerbating factors such as hypoxemia, hypercarbia, acidosis, hypothermia, hypervolemia, and increased intrathoracic pressure; monitoring and optimizing right ventricular function; and treatment with selective pulmonary vasodilators. Recent advances in pharmacology provide anesthesiologists with a wide variety of options for selective pulmonary vasodilatation. Pulmonary hypertension is a major determinant of perioperative morbidity and mortality in special situations such as heart and lung transplantation, pneumonectomy, and ventricular assist device placement.

Primary graft dysfunction: lessons learned about the first 72 h after lung transplantation

PURPOSE OF REVIEW

In 2005, the International Society for Heart and Lung Transplantation published a standardized definition of primary graft dysfunction (PGD), facilitating new knowledge on this form of acute lung injury that occurs within 72 h of lung transplantation. PGD continues to be associated with significant morbidity and mortality. This article will summarize the current literature on the epidemiology of PGD, pathogenesis, risk factors, and preventive and treatment strategies.

RECENT FINDINGS

Since 2011, several manuscripts have been published that provide insight into the clinical risk factors and pathogenesis of PGD. In addition, several transplant centers have explored preventive and treatment strategies for PGD, including the use of extracorporeal strategies. More recently, results from several trials assessing the role of extracorporeal lung perfusion may allow for much-needed expansion of the donor pool, without raising PGD rates.

SUMMARY

This article will highlight the current state of the science regarding PGD, focusing on recent advances, and set a framework for future preventive and treatment strategies.

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.

Comparison of extracorporeal membrane oxygenation versus cardiopulmonary bypass for lung transplantation

OBJECTIVE

This study compared differences in patient outcomes and operative parameters for extracorporeal membrane oxygenation (ECMO) versus cardiopulmonary bypass (CPB) in patients undergoing lung transplants.

METHODS

Between January 1, 2008, and July 13, 2013, 316 patients underwent lung transplants at our institution, 102 requiring intraoperative mechanical cardiopulmonary support (CPB, n=55; ECMO, n=47). We evaluated survival, blood product transfusions, bleeding complications, graft dysfunction, and rejection.

RESULTS

Intraoperatively, the CPB group required more cell saver volume (1123±701 vs 814±826 mL; P=.043), fresh-frozen plasma (3.64±5.0 vs 1.51±3.2 units; P=.014), platelets (1.38±1.6 vs 0.43±1.25 units; P=.001), and cryoprecipitate (4.89±6.3 vs 0.85±2.8 units; P<.001) than the ECMO group. Postoperatively, the CPB group received more platelets (1.09±2.6 vs 0.13±0.39 units; P=.013) and was more likely to have bleeding (15 [27.3%] vs 3 [6.4%]; P=.006) and reoperation (21 [38.2%] vs 7 [14.9%]; P=.009]. The CPB group had higher rates of primary graft dysfunction at 24 and 72 hours (41 [74.5%] vs 23 [48.9%]; P=.008; and 42 [76.4%] vs 26 [56.5%]; P=.034; respectively). There were no differences in 30-day and 1-year survivals.

CONCLUSIONS

Relative to CPB, the ECMO group required fewer transfusions and had less bleeding, fewer reoperations, and less primary graft dysfunction. There were no statistically significant survival differences at 30 days or 1 year.

[Lung transplantation in sporadic lymphangioleiomyomatosis: study of 7 cases]

BACKGROUND AND OBJECTIVE

Sporadic lymphangioleiomyomatosis (S-LAM) is a rare disease that affects only women. It is characterized by an abnormal proliferation of immature smooth muscle cells (LAM cells) that grow in an aberrant manner in the airway, parenchymal lung lymph and blood vessels, determining the onset of pulmonary cystic lesions. The disease has no treatment, progressing to respiratory failure, and lung transplantation (LT) may be a treatment option at this stage. Our goal was to study 7 patients undergoing LT for S-LAM.

MATERIAL AND METHOD

We studied a series of clinical and demographic characteristics, diagnostic modality and post-transplant outcomes. We performed a descriptive analysis of the series. The Kaplan-Meier method was used to estimate survival.

RESULTS

The mean age of onset of symptoms was 35 years, the diagnosis of 37 years and that of LT 38 years. The most common symptom was dyspnea. Four patients had a history of pneumothorax and pleural effusion. The mean forced expiratory volume in one second was 32.7% and the diffusing capacity for carbon monoxide was 29%. All patients were subjected to LT and survival was 100, 85.7 and 57.1% at one, 3 and 5 years, respectively. Three died of bronchiolitis obliterans and 2 necropsies did not show evidence of disease recurrence.

CONCLUSIONS

LT is a therapeutic option in patients with S-LAM with an advanced respiratory functional impairment.

Primary graft dysfunction

Primary graft dysfunction (PGD) is a syndrome encompassing a spectrum of mild to severe lung injury that occurs within the first 72 hours after lung transplantation. PGD is characterized by pulmonary edema with diffuse alveolar damage that manifests clinically as progressive hypoxemia with radiographic pulmonary infiltrates. In recent years, new knowledge has been generated on risks and mechanisms of PGD. Following ischemia and reperfusion, inflammatory and immunological injury-repair responses appear to be key controlling mechanisms. In addition, PGD has a significant impact on short- and long-term outcomes; therefore, the choice of donor organ is impacted by this potential adverse consequence. Improved methods of reducing PGD risk and efforts to safely expand the pool are being developed. Ex vivo lung perfusion is a strategy that may improve risk assessment and become a promising platform to implement treatment interventions to prevent PGD. This review details recent updates in the epidemiology, pathophysiology, molecular and genetic biomarkers, and state-of-the-art technical developments affecting PGD.

[ECMO in lung transplantation]

New technologies have become available to minimize the adverse events of extracorporeal devices. Link to these technological improvements ECMO in lung transplantation is currently essential. Bridging to lung transplantation changes to concepts avoiding the sequels mechanical ventilation and thereby offers improvement of lung recipients prior to the transplant procedure. Its use as hemodynamic and respiratory support during the lung transplant surgery can replace conventional Cardiopulmonary bypass. And finally, ECMO is sometimes the only alternative in the most severe forms of primary graft failure.

[Place of traditional CBP in bipulmonary transplantation]

Initially double-lung transplantation (DLT) was performed with airway anastomosis at the tracheal bifurcation requiring a cardiopulmonary bypass (CBP). Complications related to ischemia of the bronchi and trachea around the carina prompted adoption of sequential single lung implantations as the method of choice for DLT. In different studies, CPB was associated with an increase in postoperative morbidity but this was probably due to the selection of more severe patients. Moreover, important progress in the technology of CPB has occurred. Therefore, the systematic use of CPB during sequential lung transplantation might have some interest by limiting the occurrence of ventilation and perfusion injuries. This article discusses the potential beneficial effects of CPB during double-lung transplantation.

Primary graft dysfunction

Primary graft dysfunction (PGD) is the most important cause of early morbidity and mortality following lung transplantation. PGD affects up to 25% of all lung transplant procedures and currently has no proven preventive therapy. Lung transplant recipients who recover from PGD may have impaired long-term function and an increased risk of bronchiolitis obliterans syndrome. This article aims to provide a state-of-the-art review of PGD epidemiology, outcomes, and risk factors, and to summarize current efforts at biomarker development and novel strategies for prevention and treatment.

Transplantation in Chronic Obstructive Pulmonary Disease

Lung transplantation is a surgical option for patients who fail optimization of medical treatment for the severe symptoms that result from COPD. This review will discuss patient selection, transplant listing, and the surgical technique for transplantation in COPD. Furthermore, it will describe transplant outcomes and its effects on recipient survival, pulmonary function, exercise capacity, respiratory muscle function, and quality of life. The respective roles of transplantation and lung volume reduction surgery as therapies for advanced disease will be outlined.

Pathogenesis, management, and consequences of primary graft dysfunction

Primary graft dysfunction continues to be a major contributing factor to morbidity and mortality after lung transplantation. This condition is presumed to be the result of ischemia-reperfusion injury, which is associated with the release of endogenous substances that can activate the innate immune system. Primary graft dysfunction has been shown to be an independent risk factor for the development of bronchiolitis obliterans syndrome indicating that it can shape alloimmune responses. In this review, we focus on the classification, pathogenesis, possible prevention strategies, management and consequences of primary graft dysfunction.

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.

Influence of normothermic cardiopulmonary bypass on body oxygen metabolism during lung transplantation

Studies have demonstrated that cardiopulmonary bypass (CPB) adversely affects pulmonary circulation, which is involved in metabolism in the lung, and that pulmonary circulation after CPB can restore the prostaglandin E2 (PGE2) level mainly standing for levels of key vasostimulators augmented during CPB, which may influence systemic tissue perfusion and body oxygen metabolism. However, in lung transplantation (Lx), pulmonary circulation is restored to the graft, which might induce another CPB reaction. We prospectively examined the influence of CPB on body oxygen metabolism in Lx. Left Lx was successfully performed on 10 dogs (group-on: with normothermic CPB without cardiac arrest, group-off: without CPB; n = 5 vs. 5). At 30 minutes after graft perfusion, the right pulmonary artery and bronchus were clamped. Body weight, donor-to-recipient body weight ratio, and clinical parameters were comparable between the two groups, except for the hematocrit level during CPB. At 90 minutes after graft perfusion, mixed venous oxygen saturation (SvO2) was lower (p < 0.01) and O2 extraction rate (p < 0.01), PGE2 (p = 0.025), and arterial blood ketone body ratio (KBR) (p < 0.01) were higher in group-on than in group-off, whereas these parameters were comparable before graft perfusion between the two groups. O2 consumption and acetic acid were higher in group-on than in group-off, whereas O2 delivery and 3-hydroxy propioic acid were comparable between the groups. In conclusion, Lx during CPB may induce a new inflammatory reaction and influence body oxygen metabolism, contrary to the restoration of pulmonary circulation after CPB.

Ultrafiltration attenuates cardiopulmonary bypass-induced acute lung injury in a canine model of single-lung transplantation

OBJECTIVE

The purpose of this study was to investigate the effects of cardiopulmonary bypass and ultrafiltration on graft function in a canine single-lung transplantation model.

METHODS

Fifteen left single-lung transplantations were done in weight-mismatched canine pairs. The animals were divided into 3 groups: group 1, in which transplantation was done without cardiopulmonary bypass; group 2, in which transplantation was done with cardiopulmonary bypass and in which the cardiopulmonary bypass flow was decreased slowly with controlled pulmonary artery pressure; and group 3, in which transplantation was done with cardiopulmonary bypass and ultrafiltration. Hemodynamic parameters and lung function were monitored for 6 hours after reperfusion. The grafts were harvested for histologic studies, myeloperoxidase assay, and real-time quantitative reverse transcription-polymerase chain reaction of mRNA encoding interleukin 6.

RESULTS

The hemodynamic parameters were similar among the 3 groups. In group 1 PaO2 and alveolar to arterial gradient for O2 levels were excellent throughout the 6-hour observation period, but in group 2 they progressively deteriorated. However, ultrafiltration significantly (P = .02) improved the PaO2 level in group 3. On histology, interstitial edema and polynuclear cell infiltration were most marked in group 2 and significantly worse than in groups 1 and 3. Myeloperoxidase assay and real-time quantitative reverse transcription-polymerase chain reaction showed increased myeloperoxidase activity and interleukin 6 gene expression in group 2 grafts compared with group 1 grafts. Myeloperoxidase activity and interleukin 6 gene expression were suppressed with ultrafiltration.

CONCLUSIONS

Cardiopulmonary bypass had negative effects on the graft, but ultrafiltration attenuated acute lung dysfunction by reducing the inflammatory response.

Cardiopulmonary bypass for lung transplantation in cystic fibrosis: pilot evaluation of perioperative outcome

OBJECTIVE

The purpose of this study was to determine whether cardiopulmonary bypass (CPB) reduces the incidence of perioperative graft infection after lung transplantation in adults with cystic fibrosis (CF).

DESIGN

Retrospective and observational.

SETTING

University hospital.

PARTICIPANTS

Adults with CF who underwent lung transplantation (1998-2003).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cohort size was 26: group A (n = 10) who underwent CPB for implantation of both lungs, group B (n = 8) who underwent CPB only for implantation of the second lung, and group C (n = 8) who did not undergo CPB. The 3 cohort subgroups were similar (p > 0.05) in demographics, preoperative lung function, and anesthetic management. Group A had a lower incidence of perioperative pneumonia (p = 0.02). CPB exposure increased transfusion (B > A > C) of fresh frozen plasma and platelets but not packed red blood cells. There were no differences (p > 0.05) in clinical outcome as reflected by duration of mechanical ventilation, tracheal re-intubation, re-exploration for bleeding, sepsis, primary graft dysfunction, renal dysfunction, length of stay, and mortality.

CONCLUSIONS

CPB is associated with decreased incidence of early graft infection after lung transplantation for adult CF when used for implantation of both lungs. This may be because of improved decontamination of the operative field before graft implantation.

Use of an apical heart suction device for exposure in lung transplantation

Cardiopulmonary bypass is not necessary for the performance of bilateral sequential lung transplantation in most circumstances. Inadequate exposure to the left hilum is occasionally the sole indication for institution of cardiopulmonary bypass. We report the use of a suction heart positioning device to allow lifting of the heart for improvement of left hilar exposure. This technique has decreased the need for cardiopulmonary bypass when bypass is indicated due to difficult operative exposure.

Use of cardiopulmonary bypass for lung transplantation: a 10-year experience

OBJECTIVE

The use of cardiopulmonary bypass (CPB) for lung transplantation (LTx) has been reported previously. This study reports the authors' experience of planned and unplanned use of cardiopulmonary bypass for LTx.

DESIGN

Case series.

SETTING

A university teaching hospital.

PARTICIPANTS

Patients undergoing LTx.

INTERVENTIONS

A retrospective analysis of the charts of all patients having undergone LTx over the last 10 years.

MEASUREMENTS AND MAIN RESULTS

Among 140 LTx, 23 (16%) were performed with the use of CPB. CPB was planned in 11 cases and unplanned in the 12 other cases. The use of CPB is associated with a longer period of postoperative mechanical ventilation, more pulmonary edema, more blood transfusion requirement, and an increase in postoperative mortality at 48 hours and 1 month. Surgical difficulties related to the dissection of the native left lung and acute right ventricular failure are the main reasons for unscheduled use of CPB.

CONCLUSION

Scheduled and unscheduled CPB for LTx are associated with an increased mortality at 1 month and 1 year.

Extended donor criteria in lung transplantation: Impact on organ allocation

OBJECTIVE

Some reports have documented a higher early mortality with the use of extended criteria donors in lung transplantation. None have evaluated how outcomes compare with the use of these organs for single and bilateral transplantation or whether this practice results in a higher incidence of early bronchiolitis obliterans syndrome.

METHODS

We performed a retrospective review of case notes, intensive therapy unit database, and donor details. Between January 1, 2000, and December 31, 2004, 201 patients underwent lung or heart-lung transplantation.

RESULTS

Eighty-three (41.3%) patients received organs deemed marginal on the basis of at least one of the following criteria: donor age greater than 55 years, duration of ventilation greater than 5 days, purulent secretions or inflammation at bronchoscopy, smoking of 20 or more cigarettes per day, abnormality on chest roentgenogram, or PO2/fraction of inspired oxygen ratio of less than 300 mm Hg immediately before donor organ procurement. Recipients of marginal lungs had a higher incidence of severe (grade 3) primary graft dysfunction (43.9% vs 27.4%, P = .015) and 90-day organ-specific mortality (15.7% vs 5.1%, P = .012). Bilateral transplantation carried a significantly higher 30-day mortality if performed with marginal organs (17.0% vs 2.7% with standard donor organs, P = .005). Thirty-day mortality was not significantly different for the transplantation of single marginal or standard donor lungs. Cumulative survival and survival free of bronchiolitis obliterans syndrome was not affected by marginal donor status.

CONCLUSION

Transplantation of extended criteria donor lungs leads to a higher incidence of primary graft dysfunction. Bilateral transplantation with these organs seems to confer less reserve, resulting in a higher early mortality rate. Medium-term functional outcome is, however, not adversely affected by the relaxation of donor criteria.

Is Routine Coronary Angiography and Revascularization Indicated Among Patients Undergoing Evaluation for Lung Transplantation?

OBJECTIVES

To review coronary artery disease (CAD) prevalence among lung transplantation (LTx) candidates, the time interval from coronary angiography (CA) to LTx/death, and post-revascularization outcomes.

BACKGROUND

CA is advised for LTx candidates because significant CAD is a contraindication for LTx.

METHODS

We monitored all LTx candidates from 1997 who underwent CA. Significant CAD was defined as stenosis > or = 70% in diameter.

RESULTS

Of 118 candidates > 40 years old (68.3% men; median age, 58 years; 25 to 75th interquartiles, 53 to 61 years), 59 patients underwent LTx, 56 patients were eligible for LTx, and 3 patients were excluded due to CAD. Significant CAD was detected in 21 patients (17.8%), nonsignificant CAD was found in 21 patients (17.8%), and no CAD was found in 76 patients (64.4%), without significant differences in the demographic/clinical profile among patients with or without significant CAD. Among 21 patients with significant CAD, 12 patients (57.1%) underwent successful percutaneous coronary intervention (PCI), 1 patient had failed to respond to PCI, and 8 patients (38.1%) had no intervention. After PCI, one patient had periprocedural infarction, one patient had stent thrombosis, and one patient had symptomatic restenosis. The median time interval CA to LTx/death/last visit among the 115 candidates was 166 days (interquartiles, 48 to 410 days). Death occurred before LTx in 30 patients (53.5%) during a follow-up of 312 days (interquartiles, 46 to 664 days) and after LTx in 14 patients (23.7%) during a follow-up of 142 days (interquartiles, 73 to 304 days), without any difference in outcome based on severity of CAD in the two groups (p = 0.7 and p = 0.6, respectively).

CONCLUSIONS

CAD prevalence among LTx candidates is low and cannot be accurately predicted by risk factors. Revascularization may be associated with complications, and the time interval between revascularization and LTx may be long. Conversely, certain patients with significant CAD underwent LTx without complications. The practice of routine CA and revascularization prior to LTx should be reconsidered, and perhaps reserved for selected patients with high-risk features.

Outcome of lung transplantation for patients requiring concomitant cardiac surgery

BACKGROUND

The clinical results of lung transplantation and concomitant cardiac surgery are unclear. The effect of cardiopulmonary bypass on the pulmonary allograft is controversial, and the effect of cardiac arrest and cardiac surgery in this setting is unknown. Our aim was to review the operative results and long-term survival in this group of patients.

METHODS

A retrospective review of all lung transplantations between 1988 and 2003 was performed. Patients who had concomitant cardiac surgery during lung transplantation were compared with those who underwent lung transplantation alone. The variables analyzed included allograft ischemic times, use of cardiopulmonary bypass, early graft dysfunction, postoperative morbidity, survival, length of mechanical ventilation, length of stay in the intensive care unit, and overall hospital stay.

RESULTS

During this period, 35 of 700 lung transplant recipients (15 single and 20 bilateral transplantations) underwent concomitant cardiac surgery. The cardiac procedures were for patent foramen ovale (n = 18), atrial septal defect (n = 9), ventricular septal defect (n = 2), coronary bypass (n = 4), and "other" (n = 2). Allograft ischemic time, use of extracorporeal membrane oxygenation, length of hospital stay, operative mortality, and survival were not significantly different between the 2 groups. Ventilator time and intensive care unit stay were longer in the cardiac surgery group.

CONCLUSIONS

Cardiac surgery at the time of lung transplantation can be performed with acceptable morbidity and mortality. The immediate and long-term survival in these patients is similar to that of other lung transplant recipients. Lung transplantation should continue to be offered to patients with normal ventricular function who require concomitant limited cardiac surgery.

Lung transplantation for emphysema

Great strides have been made in lung transplantation in the past two decades. Changes in technique, immunosuppression regimens, and treatment of infectious complications have led to improvements in survival and functional results. Current areas of discussion concern the use of single lung transplantation versus bilateral sequential lung transplantation and the criteria for allocating donor lungs. This article reviews the current state of lung transplantation for emphysema and provides insight from more than one decade of experience with Washington University's lung transplant program.