Bronchiolitis obliterans is not the primary cause of death in pediatric living donor lobar lung transplant recipients

Living-donor lobar lung transplantation

Living-donor lobar lung transplantation (LDLLT) is indicated for critically ill patients who would not survive the waiting period in the case of severe brain-dead donor shortage. It is essential to confirm that potential donors are willing to donate without applying psychological pressure from others. In standard LDLLT, the right and left lower lobes donated by 2 healthy donors are implanted into the recipient under cardiopulmonary support. LDLLT can be applied to various lung diseases including restrictive, obstructive, infectious, and vascular lung diseases in both adult and pediatric patients if size matching is acceptable. Functional size matching by measuring donor pulmonary function and anatomical size matching by 3-dimensional computed tomography volumetry are very useful. When 2 donors with ideal size matching are not available, various transplant procedures, such as single lobe, segmental, recipient lobe-sparing, and inverted lobar transplants are valuable options. There seems to be immunological advantages in LDLLT as compared to cadaveric lung transplantation (CLT). Unilateral chronic allograft dysfunction is a unique manifestation after bilateral LDLLT, which may contribute to better prognosis. The growth of adult lung graft implanted into growing pediatric recipients is suggested by radiologic evaluation. Although only 2 lobes are implanted, postoperative pulmonary function is equivalent between LDLLT and CLT. The long-term outcome after LDLLT is similar to or better than that after CLT. The author has performed 164 LDLLTs resulting in 71.6% survival rate at 10 years. All living-donors returned to their previous life styles. Because of possible serious morbidity in donors, LDLLT should be applied only for critically ill patients.

Paediatric lung transplantation: the impact of age on the survival

OBJECTIVES

We herein review the outcomes of paediatric lung transplantation (LTx) and analyse subgroups divided by age.

METHODS

We retrospectively reviewed 43 consecutive paediatric LTx recipients (< 18 years old: cadaveric LTx [n = 9], living-donor lobar LTx [n = 34]). We also analysed subgroups of patients 1-6 years old (n = 10) and 7-17 years old (n = 33).

RESULTS

The 1-, 5- and 10-year overall survival (OS) rates in paediatric recipients were 93%, 82% and 67%, respectively. The 1-, 5- and 10-year graft dysfunction (GD)-free survival rates in paediatric recipients were 85%, 59% and 31%, respectively. The 1- and 5-year OS in the 1- to 6-year-old vs. 7- to 17-year-old groups were 70% vs. 100% and 48% vs. 93%, respectively (p < 0.0001). The 1- and 5-year GD-free survival rates in the 1- to 6-year-old vs. 7- to 17-year-old groups were 60% vs. 93% and 24% vs. 69%, respectively (p = 0.024). The 1- to 6-year-old group showed higher rates of non-standard LTx (p = 0.0001), interstitial pneumonia (p = 0.004) and ventilator dependency (p = 0.007) than the 7- to 17-year-old group.

CONCLUSION

Paediatric recipients under 7 years old seemed to have a higher risk of mortality and GD than those 7 years old and older.

Pediatric Recipients of Living Donor Lobar Lung Transplants: Postoperative Care

Bilateral living donor lobar lung transplantation is a treatment option for selected children and adults with end-stage lung disease. Careful donor evaluation, skilled intraoperative management and surgical technique, and diligent immediate postoperative care and follow-up all contribute to better outcomes. Although medical management of whole lung transplant recipients in the immediate postoperative period is similar to that of lobar lung transplant recipients, there are specific differences. Anatomical distinctions, such as the entire cardiac output flowing to 2 lobes instead of 5, and thoracic space issues with simultaneous mechanical ventilation and chest tube suction, contribute to these differences. Early postoperative care, including initial postoperative stabilization, ventilation, fluid management, rejection/infection surveillance and prophylaxis, and beginning rehabilitation, can be adapted to ensure successful outcomes in these patients.

Buying time: The use of extracorporeal membrane oxygenation as a bridge to lung transplantation in pediatric patients

To describe our experience to date of four children with end-stage lung disease who have been bridged with ECMO to successful lung transplantation in our institution. Between March 2006 and June 2012, a total of 21 pediatric patients successfully underwent lung transplantation within The Alfred's lung transplantation program. This included four children who were bridged on ECMO prior to transplantation according to the "ECMO bridge to transplant" protocol and whose clinical notes and outcomes were reviewed. Lung transplantation is an established life-saving treatment for patients with severe lung disease, but remains limited due to scarcity of suitable donor organs. This is a particular issue in the pediatric setting, where the smaller child waits disproportionately longer compared with adult patients for size-matched donor lungs. As ECMO has become more widely accepted, its use as a bridge to lung transplantation in pediatric patients with severe acute lung injury or end-stage chronic lung disease has been considered. The medical notes from the four pediatric patients were retrospectively reviewed. Our report describes excellent short- and medium-term outcomes in a small number of children who have been bridged to transplant on ECMO.

Overview of lung transplantation

Although significant gains have been made in improving lung function and survival in cystic fibrosis (CF), ultimately respiratory failure is the leading cause of mortality in these patients. For CF patients with end stage lung disease, lung transplantation is an option for treatment. The field of lung transplantation has progressed markedly in the last 20 years. Nonetheless it remains a technically complex and challenging procedure, and patients are at risk for numerous short term and long term complications. Potential transplant recipients must be physically and psychologically prepared for the arduous process involved in lung transplantation. This article will review the history of lung transplantation, indications for transplantation, surgical techniques, and complications of transplantation.

A national conference to determine research priorities in pediatric solid organ transplantation

The need for evidence-based practice guidelines requires high quality, carefully controlled clinical research trials. This multidisciplinary conference attempted to: identify urgent clinical and research issues, identify obstacles to performing clinical trials, develop concepts for organ-specific and all-organ research and generate a report that would serve as a blueprint for future research initiatives. A few themes became evident. First, young children present a unique immunologic environment which may lead to tolerance, therefore, including young children in immunosuppression withdrawal and tolerance trials may increase the potential benefits of these studies. Second, adolescence poses significant barriers to successful transplantation. Non-adherence may be insufficient to explain poorer outcomes. More studies focused on identification and prevention of non-adherence, and the potential effects of puberty are required. Third, the relatively naive immune system of the child presents a unique opportunity to study primary infections and alloimmune responses. Finally, relatively small numbers of transplants performed in pediatric centers mandate multicenter collaboration. Investment in registries, tissue and DNA repositories will enhance productivity. The past decade has proven that outcomes after pediatric transplantation can be comparable to adults. The pediatric community now has the opportunity to design and complete studies that enhance outcomes for all transplant recipients.

Mechanisms of chronic rejection in cardiothoracic transplantation

Despite significant improvements in early post-transplantation survival rates, long-term patient and graft survival have remained poor, due in large part to the vexing problem of chronic allograft rejection. Attempts to combat this problem with intensification of immunosuppression have led to concomitant increases in the rates of fatal malignancies and infections. In cardiac transplantation, chronic rejection is manifested primarily by a disease entity known as cardiac allograft vasculopathy, an occlusive narrowing of the coronary vessels. In lung transplantation, chronic rejection is typified by obliterative bronchiolitis, an airflow limiting narrowing of the bronchioles. From an immunologic standpoint, chronic rejection is believed to be the end result of repeated immune and non-immune insults to the graft. This review examines the pathophysiology of heart and lung chronic, with emphasis on both immune and non-immune causes.

Lung transplantation for cystic fibrosis: Current concepts and one center's experience

BACKGROUND

Although new approaches to the treatment of patients with cystic fibrosis (CF) are significantly prolonging their lives, most patients will eventually develop respiratory failure due to progressive bronchiectasis caused by chronic lung infection and inflammation and die from to respiratory failure. We examined our center's (University of Wisconsin Hospital and Clinics) experience with lung transplantation for patients with CF and reviewed the literature to examine current and evolving approaches to transplantation for this indication.

METHODS

We reviewed all published literature pertaining to lung transplantation for CF through 2006, and we reviewed all aspects of transplantation for patients with CF at our institution from 1994 to 2005.

RESULTS

Major complications following lung transplantation include acute rejection, bacterial infection, and bronchiolitis obliterans. Five-year survival at UWHC (Kaplan-Meier) is 67%, and survival was not adversely affected by transplanting patients receiving mechanical ventilation. The major cause of death for transplant recipients was bronchiolitis obliterans syndrome (BOS).

CONCLUSIONS

Lung transplantation for CF is associated with acceptable survival rates and can improve quality of life. Lung transplant should be offered to all patients with advanced CF lung disease if they meet currently accepted inclusion and exclusion criteria.

American Society of Transplantation executive summary on pediatric lung transplantation

Lung transplantation in children poses distinctly different challenges from those seen in the adult population. This consensus statement reviews the experience in the field of pediatric lung transplantation and highlights areas that deserve further investigation.

Pediatric living donor lobar lung transplantation

Living donor lobar lung transplantation (LDLLT) was developed in order to mitigate the growing competition for deceased donor (DD) lungs and resultant increase in waiting list mortality. Because each of the two donor lobes serves as an entire lung for the recipient, donors who are taller than the recipient are preferred. Therefore LDLLT is particularly well suited for pediatric recipients for whom adults serve as donors. Although long-term outcomes after LDLLT reported by the Organ Procurement and Transplantation Network (OPTN) are worse compared with DD recipients, overall pediatric outcomes as well as single center reports from the most experienced programs are more promising. Particularly encouraging are the findings that bronchiolitis obliterans (OB) is less frequent or less severe in LDLLT recipients in comparison to DD recipients. Moreover, outcomes may be improved by careful selection of donors to ensure adequately sized donor lobes and minimization of infectious risks. Although no donor deaths have been reported, there is a moderate risk of significant short-term complications. Long-term follow-up has not been reported. The use of LDLLT has decreased in recent years, and the recent change by the OPTN to an urgency/benefit allocation system for DD lungs in patients 12 yr and older may further reduce the demand. Nonetheless, we anticipate that LDLLT will continue to be utilized in select circumstances, particularly in children under 12 where access to DD organs remains challenging.

Anesthesia Considerations for Pediatric Thoracic Solid Organ Transplant

This article discusses the indications, perioperative management, postoperative complications, and patient outcome of pediatric heart transplantation and pediatric lung transplantation. Special emphasis is placed on the anesthetic considerations relevant for children who are undergoing or have received a solid thoracic organ transplant.

Living Donor Lobar Lung Transplantation: Current Status and Future Directions

Living lobar lung transplantation was developed as a procedure for adult and pediatric patients considered too ill to await cadaveric transplantation. One hundred thirty-eight living lobar transplants have been performed in 133 patients at our institution between January 1993 and September 2004. Actuarial 1-, 3-, and 5-year survival are similar to ISHLT registry data. There has been no donor mortality, and morbidity has been relatively low. Long-term postoperative pulmonary function studies demonstrate the relatively smaller-sized lobes can provide similar pulmonary function and exercise capacity to bilateral cadaveric lung transplants. Living lobar lung transplantation should be considered a viable option in patients with end-stage lung disease deemed unable to await a cadaveric organ and in those patients in which further deterioration would make cadaveric transplantation inappropriate.

The Ethics of Living Donor Lung Transplantation

A constant awareness of the risk to the living donors must be maintained with any living donor organ transplantation program, and comprehensive short- and long-term follow-up should be strongly encouraged to maintain the viability of these potentially life-saving procedures. There has been no perioperative or long-term mortality following lobectomy for living lobar lung transplantation, and perioperative risks associated with donor lobectomy seem to be similar to those seen with standard lung resections. These risks might increase, however, if the procedure is offered on an occasional basis and not within a well-established program. The long-term outcomes and functional effects of lobar donation raise important questions that are unanswered. This has proved difficult to follow closely, because of the fact that many donors live far from the transplant medical center and are reluctant to return for routine follow-up evaluation. The death of a recipient can further exacerbate this situation, because there is reluctance to insist on further routine examinations for a grieving donor. Prospective donors must be informed of the morbidity associated with lobectomy and the potential for mortality, and for potential negative recipient outcomes in regard to life expectancy and quality of life after transplantation. Although cadaveric transplantation must be considered because of the risk to the donors, living lobar lung transplantation should continue to be used under properly selected circumstances. The results reported by the authors' group and others are important if this procedure is to be considered as an option at more pulmonary transplant centers in view of the institutional, regional, and international differences in the philosophic and ethical acceptance of the use of living organ donors for transplantation. The integration of ethical discussion into topics that are relevant and of interest to thoracic surgeons, such as living lung donation, is a recent and welcome event. Many of the clinical situations that thoracic surgeons deal with on a daily basis have important and complex ethical implications, and there has been little training to deal effectively with these issues. This is changing as invited discussions on ethically compelling topics are finding their way into journals and the programs of national meetings. What may be of more importance, however, is the development of an ethics curriculum for those training in the specialty. The core curriculum recommended by the Thoracic Surgical Directors Association (which represents the leadership of the 89 approved residency training programs in the United States) has one lecture pertaining to ethics out of the several hundred offerings in its requisite curriculum. It is hoped that this will change in the near future.

Human leukocyte antigen-DR expression on peripheral blood monocytes and the risk of pneumonia in pediatric lung transplant recipients

BACKGROUND

Pneumonia is the leading cause of morbidity and mortality after living lobar lung transplantation (LT). Low levels of human leukocyte antigen-DR (HLA-DR) expression on peripheral blood monocytes, have been demonstrated to correlate with risk of infection in surgical, trauma, and adult transplant patients. In addition, interleukin (IL)-10 has been shown to be a negative regulator of HLA-DR expression. This study investigates whether HLA-DR expression and serum IL-10 levels correlate with the development of pneumonia after pediatric LT.

METHODS

Thirteen LT recipients were prospectively monitored with blood samples obtained pre-LT (baseline) and post-LT weeks 1-4. Mean fluorescence intensity (MFI) of HLA-DR on CD14+ monocytes was measured by flow cytometry. IL-10 levels were determined by ELISA from frozen serum collected at the same time points as monocyte HLA-DR expression. Correlates of pneumonia were abstracted from the medical record.

RESULTS

Monocyte HLA-DR expression declined in 11 of 13 patients in the first week post-LT. Two patients without an initial decline and four others whose HLA-DR expression recovered by week 2 post-LT, did not develop pneumonia or other infection or rejection. Pneumonia was observed in seven patients, six of whom failed to recover their monocyte HLA-DR expression by 2 weeks post-LT. Six of seven patients with pneumonia recovered, and one patient died of aspergillosis. During weeks 1-4, a statistically significant difference was seen in the profile of mean monocyte HLA-DR expression levels, analyzed as percent of baseline, between the patients with and without pneumonia (P=0.002). The greatest difference between groups over time was seen from post-LT weeks 1-2 (P=0.003). In addition, when comparing the values at each week, a significant difference was seen between the two groups at post-LT week 2 (P=0.006) and week 4 (P=0.05). Analysis of IL-10 concentrations revealed that the overall difference between the groups (patients with and without pneumonia) was statistically significant (P=0.014), with a paradoxical positive correlation between HLA-DR expression at post-LT week 4 and IL-10 concentrations.

CONCLUSIONS

Persistent low monocyte HLA-DR expression was associated with the risk of post-LT pneumonia in these patients. This measurement may be useful for monitoring risk of infection and stratifying patients into higher and lower risk groups. Increased IL-10 levels may be protective for infection in this group of patients. At present it is unknown whether the predictive power of HLA-DR expression is indicative of a global defect in monocytic function or a specific abnormality.

Long-term Pulmonary Function After Living-donor Lobar Lung Transplantation in Adults

BACKGROUND

Living-donor lobar lung transplantation was developed as an alternative to cadaveric transplantation. However, whether two pulmonary lobes provide comparable intermediate and long-term pulmonary function to full-sized bilateral cadaveric grafts in adults is unknown.

METHODS

An analysis of the pulmonary functions of 59 bilateral lobar and 43 bilateral cadaveric adult lung transplant recipients who survived more than 3 months after transplantation was performed.

RESULTS

Mean follow-up was 3.8 +/- 2.8 years. In lobar recipients, mean percent predicted forced vital capacity and forced expiratory volume in 1 second improved between 1 and 6 months after transplantation (42.5% +/- 13.4% and 46.9% +/- 14.0% at 1 month versus 63.6% +/- 14.1% and 64.5% +/- 13.7% at 6 months; p < 0.001 and <0.001, respectively). In cadaveric recipients, mean percent predicted forced vital capacity improved after transplantation (54.3% +/- 14.5% at 1 month versus 74.2% +/- 21.3% at 12 months; p < 0.01). As compared with the cadaveric group, mean percent predicted forced vital capacity and forced expiratory volume in 1 second were lower 1 and 3 months after transplantation in the lobar recipients (p = 0.001 at both times); however, by 6 months after transplantation, these values were comparable and remained so throughout the follow-up period. In a subset of lobar and cadaveric recipients, maximal exercise, heart rate, peak oxygen consumption, anaerobic oxygen consumption threshold, and ability to maintain oxygen saturation were also comparable.

CONCLUSIONS

In those adult recipients surviving more than 3 months after transplantation, lobar lung transplantation provides comparable intermediate and long-term pulmonary function and exercise capacity to bilateral cadaveric lung transplantation.

Donor brain death aggravates chronic rejection after lung transplantation in rats

BACKGROUND

Many recipients of lung transplants from brain-dead donors develop bronchiolitis obliterans, a manifestation of chronic rejection. It has been shown that brain death increases inflammatory mediators and accelerates acute rejection in kidney, liver, and heart transplants. In this study, the authors investigated the hypothesis that brain death increases inflammatory mediators in the donor lung and subsequently aggravates chronic rejection of the lungs after transplantation in rats.

METHODS

Brain death was induced in F344 rats by inflation of a subdurally placed balloon catheter. After 6 hr, donor lungs were assessed for influx of leukocytes, expression of cell adhesion molecules, and cytokine mRNA expression. For assessment of the lung after transplantation, lungs from brain-dead F344 rats were transplanted into WKY rats. Lung function after transplantation was monitored by chest radiographs during an observation period of 100 days. At the end of this period, the lungs were histologically examined; also, cytokine mRNA expression was measured. Lungs from ventilated living donors and living donors served as controls.

RESULTS

After 6 hr of brain death, influx of polymorphonuclear cells and macrophages and expression of vascular cell adhesion molecule-1 in the donor lungs was increased. After transplantation at postoperative day 100, the lung function was significantly decreased compared with allografts from living donors. In the lung allografts from brain-dead donors, histologic symptoms of chronic rejection were obvious, including severe intimal hyperplasia but without bronchiolitis obliterans. Interleukin-2 mRNA was significantly increased in allografts from brain-dead donors compared with living donors.

CONCLUSIONS

This study shows that brain death induces an inflammatory response in the donor lung and subsequently aggravates chronic rejection after transplantation. This may explain the clinical difference in long-term function between lungs from cadaveric donors and living donors.

An overview of paediatric lung transplantation

Paediatric lung transplantation is indicated in selected children with end-stage lung disease that is not amenable to conventional medical or surgical therapy. The indications and complications differ from adult lung transplant patients. Due to the long waiting times for suitable cadaveric lungs, other types of lung transplantation, such as living donor lobar and split-lung procedures, have been utilised in paediatric patients. Unlike adult candidates, cystic fibrosis and primary pulmonary hypertension are the primary indications. Most recipients are in the adolescent age group. Complications that occur with greater frequency in paediatric lung recipients include somatic growth and graft function, post-transplant lymphoproliferative disease and medical non-adherence. While long-term outcome remains similar between adult and paediatric lung transplant recipients, there is a lower risk of bronchiolitis obliterans in very young recipients and in those who receive living donor lobar lung transplantation. Research into these clinical problems is hampered by the fact that only a small number of paediatric transplants are performed at each centre. Hence, improvement in outcome for these children will be dependent on developing methods to produce better tolerance, understanding the mechanisms/treatment of bronchiolitis obliterans and multi-centre studies that focus on the problems that primarily affect the paediatric lung transplant recipient.

A decade of living lobar lung transplantation: recipient outcomes

OBJECTIVE

Living lobar lung transplantation was developed as a procedure for patients considered too ill to await cadaveric transplantation.

METHODS

One hundred twenty-eight living lobar lung transplantations were performed in 123 patients between 1993 and 2003. Eighty-four patients were adults (age, 27 +/- 7.7 years), and 39 were pediatric patients (age, 13.9 +/- 2.9 years).

RESULTS

The primary indication for transplantation was cystic fibrosis (84%). At the time of transplantation, 67.5% of patients were hospitalized, and 17.9% were intubated. One-, 3-, and 5-year actuarial survival among living lobar recipients was 70%, 54%, and 45%, respectively. There was no difference in actuarial survival between adult and pediatric living lobar recipients (P =.65). There were 63 deaths among living lobar recipients, with infection being the predominant cause (53.4%), followed by obliterative bronchiolitis (12.7%) and primary graft dysfunction (7.9%). The overall incidence of acute rejection was 0.8 episodes per patient. Seventy-eight percent of rejection episodes were unilateral. Age, sex, indication, donor relationship, preoperative hospitalization status, use of preoperative steroids, and HLA-A, HLA-B, and HLA-DR typing did not influence survival. However, patients on ventilators preoperatively had significantly worse outcomes (odds ratio, 3.06, P =.03; Kaplan-Meier P =.002), and those undergoing retransplantation had an increased risk of death (odds ratio, 2.50).

CONCLUSION

These results support the continued use of living lobar lung transplantation in patients deemed unable to await a cadaveric transplantation. We consider patients undergoing retransplantations and intubated patients to be at significantly high risk because of the poor outcomes in these populations.

Pediatric lung transplantation: update 2003

In the past 15 years there have been more than 1200 pediatric lung and heart-lung transplants worldwide. This article regarding the current status of pediatric lung transplantation describes indications, outcomes, and complications, with particular emphasis on issues specific to pediatrics, including growth. Information useful to the pediatrician and pediatric pulmonologist is also included. Issues important to the future are reviewed.

Is transplant operation important in determining posttransplant risk of bronchiolitis obliterans syndrome in lung transplant recipients?

STUDY OBJECTIVES

Lung transplantation continues to be limited by the development of chronic allograft dysfunction in the form of bronchiolitis obliterans syndrome (BOS). The effect of a transplant operation on patients with BOS has not been well-studied, but patients who undergo double-lung transplantation have better long-term survival. We hypothesized that double-lung transplantation leads to decreased rates of BOS.

METHODS

A retrospective review of all lung transplant recipients at our institution, surviving for > 6 months after undergoing their transplant operation. Demographic data, information on other factors leading to the development of BOS, survival information, and data on the presence and timing of BOS were collected.

RESULTS

BOS occurred in 41.3% of the recipients (93 of 225 patients) at a median time of 4.2 years. Single-lung transplantation was associated with increased rates of BOS compared to double-lung transplantation (49.3% vs 31.7%, respectively; p = 0.007), at the time of the analysis. Single-lung and double-lung transplant recipients had different baseline characteristics, but after controlling for these factors the type of transplant remained a significant predictor of the length of time to the onset of BOS in a multivariable proportional hazard model.

CONCLUSIONS

Double-lung transplantation is associated with a reduced risk for BOS in our study population. A multicenter study with complete BOS information on all patients with a single pretransplant diagnosis would be useful to confirm the above findings. Further research is needed to determine how the type of transplant contributes to the risk for BOS.

Pediatric recipients of living donor lobar lung transplants: postoperative care

Bilateral living donor lobar lung transplantation is a treatment option for selected children and adults with end-stage lung disease. Careful donor evaluation, skilled intraoperative management and surgical technique, and diligent immediate postoperative care and follow-up all contribute to better outcomes. Although medical management of whole lung transplant recipients in the immediate postoperative period is similar to that of lobar lung transplant recipients, there are specific differences. Anatomical distinctions, such as the entire cardiac output flowing to 2 lobes instead of 5, and thoracic space issues with simultaneous mechanical ventilation and chest tube suction, contribute to these differences. Early postoperative care, including initial postoperative stabilization, ventilation, fluid management, rejection/infection surveillance and prophylaxis, and beginning rehabilitation, can be adapted to ensure successful outcomes in these patients.