Living-donor lobar lung transplantation experience: intermediate results

Effects of Growth Factors on the Differentiation of Murine ESC into Type II Pneumocytes

We have previously shown that embryonic stem cells (ESC) can be directed to differentiate into alveolar type II cells by provision of a serum-free medium designed for in vitro maintenance of mature alveolar epithelial cells (small airway growth medium: SAGM), although the target cell yield was low. SAGM comprises a basal serum-free medium (SABM) plus a series of defined supplements. In order to try increase the proportion of pneumocytes in differentiated cultures, we aimed in this study to determine the effects on murine ESC of each of the individual growth factors in SAGM. In accordance with our previous reports, expression of surfactant protein C (SPC) and its mRNA was used to monitor differentiation of type II pneumocytes. Surprisingly, we found that addition of each factor separately to SABM decreased the expression of SPC mRNA when compared with the effect of SABM alone. Thus, it seems that the observed enhancement by SAGM of pneumocyte differentiation from murine ESC can, in fact, be attributed to the provision of a serum-free environment.

Long-term Improvement in Pulmonary Function After Living Donor Lobar Lung Transplantation

BACKGROUND

As an alternative to cadaveric transplantation, living donor lobar lung transplantation (LDLLT) has been applied in critical patients with end-stage pulmonary disease because of the mismatch between the supply and demand of lungs for transplantation. However, it is unclear whether two pulmonary lobes can provide adequate long-term pulmonary function and satisfactory clinical outcome in recipients.

METHODS

Between October 1998 and September 2004, 28 females and 3 males, including 5 children, underwent LDLLT at Okayama University Hospital. Their mean age was 31.8 years, and the mean observation period was 53.8 months. One patient who underwent single-lung transplantation and another who died peri-operatively were excluded from further analyses.

RESULTS

The most common indication for transplantation was pulmonary arterial hypertension (32.3%). The overall survival rate was 93.6%. Seven recipients (22.6%) developed bronchiolitis obliterans syndrome after LDLLT. The mean percent predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) improved between 12 and 24 months after transplantation (71.8 +/- 12.9% and 65.8 +/- 17.2% at 12 months vs 77.4 +/- 16.6% and 72.8 +/- 14.6% at 24 months; p < 0.005 and p < 0.05, respectively). The actual recipient FVC ultimately reached 123.0% of the estimated graft FVC of two donor lobes (calculated based on the donor FVC and number of segments implanted) at 36 months after LDLLT.

CONCLUSIONS

Although LDLLT may be associated with the limitation of size mismatch, it holds promise for providing well-functioning pulmonary lobar grafts to critically ill patients with poor life expectancy.

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.

Bilateral native lung–sparing lobar transplantation in a canine model

OBJECTIVE

Bilateral living-donor lobar lung transplantation has become an accepted approach in response to the cadaveric lung donor shortage. Because only one lobe is implanted in each chest cavity, this procedure is usually confined to patients of small size. The purpose of this study was to develop a technique of bilateral native lung-sparing lobar transplantation that can be applied to large adult patients.

METHODS

Bilateral native lung-sparing lobar transplantation was performed in 12 pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the natural anatomic position with sparing native right upper, left upper, and middle lobes. In an acute study (n = 6), transplanted graft function was assessed for 3 hours after ligation of the pulmonary artery branches to the native spared lobes. In a chronic study (n = 6) the immunosuppressed recipients were observed for 3 weeks to assess the quality of bronchial healing and long-term pulmonary function.

RESULTS

Morphologic adaptation of the 2 grafts was found to be excellent. All 6 animals in the acute study showed excellent pulmonary function. Five of 6 animals in the chronic study survived for 3 weeks, with excellent pulmonary function and satisfactory bronchial healing.

CONCLUSION

Bilateral native lung-sparing lobar transplantation was technically possible and associated with excellent pulmonary function and good bronchial healing in a canine experimental model.

Derivation of distal airway epithelium from human embryonic stem cells

The pluripotency of embryonic stem cells (ESC) is offering new opportunities in tissue engineering and cell therapy. We have shown previously that alveolar epithelial cells, specifically type II pneumocytes, can be derived from murine ESC and hypothesized that a similar protocol could be used successfully on human ESC. Undifferentiated human ESC were induced to form embryoid bodies that were transferred into adherent culture conditions and grown in a medium designed for the maintenance of mature small airway epithelium. On inverted microscopy, the generated cells showed the cobblestone-like morphology of epithelium. The presence of surfactant protein C, a specific marker of type II pneumocytes, and its corresponding RNA were demonstrated by immunostaining and reverse transcription polymerase chain reaction, respectively. Electron microscopy revealed frequent cells with the typical ultrastructure of type II pneumocytes. This study provides evidence for in vitro induction of the differentiation from human ESC of alveolar type II cells, which have the potential for therapeutic use or construction of an in vitro model of human lung.

Ex Vivo Evaluation of Human Lungs for Transplant Suitability

BACKGROUND

If lungs could be retrieved from non-heart-beating donors, the critical shortage of lungs for transplant could be alleviated. An obstacle to this approach is the inability to predict these lungs' suitability for transplant. We used human lungs deemed unsuitable for transplant to develop a method to perfuse and ventilate human lungs ex vivo to assess gas exchange and vascular resistance, and to perform bronchoscopic inspection and radiographic evaluation.

METHODS

Lungs were retrieved from six brain-dead organ donors after cold Perfadex (Vitrolife, Kungsbacka, Sweden) flush, stored cold for 6 to 13 hours (mean, 8.7 hours) then perfused and rewarmed in a modified cardiopulmonary bypass circuit. Circuit perfusate was buffered colloid-crystalloid containing type-specific leukocyte-filtered blood (hematocrit of 10%-12%), circulated through a membrane oxygenator ventilated with CO2 and nitrogen to deoxygenate it. Lungs were ventilated with fraction of inspired oxygen (Fio2) 0.5 when 32 degrees C was reached. Gas exchange and vascular resistance was assessed at 5 L/minute flow at 37 degrees C, Fio2 0.5 and 1.0. Bronchoscopy, plain radiographs, and spiral computed tomographic (CT) scans were performed. Lung biopsies were obtained pre- and post-reperfusion.

RESULTS

Ex vivo perfusion did not cause increased wet to dry ratio, or major abnormalities by microscopy but was associated with elevated tissue levels of conjugated dienes. The alveolar-arterial difference in partial pressure of oxygen (Pao2)/Fio2 ratio in the ex vivo circuit was generally higher than in the six donors. Ex vivo radiographs and CT scans were abnormal in all lungs, confirming unsuitability of these lungs for transplant.

CONCLUSIONS

Ex vivo evaluation of human lungs is feasible and may be useful to evaluate transplant suitability of lungs retrieved after circulatory arrest from non-heart-beating donors.

Living-donor lobar lung transplantation for bronchiolitis obliterans after bone marrow transplantation

We report a successful case of living-donor lobar lung transplantation (LDLLT) for severe bronchiolitis obliterans (BO) after bone marrow transplantation (BMT). The patient is a 29-year-old woman who underwent BMT because of aplastic anemia in 1995. In 1996, BO developed in the patient because of chronic graft-versus-host disease. In May 2000, a LDLLT was performed. Pulmonary function tests showed improvement of both vital capacity and forced expiratory volume in 1 second. At present, 91 months after BMT and 38 months after lung transplantation, the patient is in good health. LDLLT may offer a therapeutic option for the treatment of BO after BMT.

A new treatment strategy for advanced idiopathic interstitial pneumonia: living-donor lobar lung transplantation

BACKGROUND

Among patients awaiting cadaveric lung transplantation, patients with idiopathic interstitial pneumonia (IIP) have been demonstrated to have the highest mortality rate. Contraindications to cadaveric lung transplantation include current high-dose systemic corticosteroid therapy because it may increase airway complications and various types of infection.

STUDY OBJECTIVES

To analyze the effect of living-donor lobar lung transplantation (LDLLT) for patients with advanced IIP including those receiving high-dose systemic corticosteroids.

DESIGN

Retrospective analysis.

SETTING

Okayama University Hospital and Okayama Medical Center.

PATIENTS

We report on the first nine patients (seven female and two male; age range, 13 to 55 years) with advanced IIP receiving LDLLT. All nine patients had a very limited life expectancy, and eight patients were dependent on systemic corticosteroid therapy as high as 50 mg/d of prednisone. LDLLT was performed under cardiopulmonary bypass using two lower lobes donated by two healthy relatives.

RESULTS

There were no airway complications in the 18 bronchial anastomoses. There was one early death (11%) due to severe acute rejection. Eight patients (89%) are currently alive with a follow-up period of 10 to 48 months. Their vital capacity reached 2.03 +/- 0.20 L (mean +/- SEM), 71.4% of predicted at 1 year. All 18 donors have returned to their previous lifestyles. Excised lungs were pathologically diagnosed as usual interstitial pneumonia (UIP) in six cases and fibrotic nonspecific interstitial pneumonia (NSIP) in three cases.

CONCLUSIONS

These early follow-up data support the option of LDLLT in patients with advanced IIP, including UIP and fibrotic NSIP, who would die soon otherwise. Current high-dose systemic corticosteroid therapy is not a contraindication in LDLLT.

Lung transplantation: opportunities for research and clinical advancement

Lung transplantation is the only definitive therapy for many forms of end-stage lung diseases. However, the success of lung transplantation is limited by many factors: (1) Too few lungs available for transplantation due to limited donors or injury to the donor lung; (2) current methods of preservation of excised lungs do not allow extended periods of time between procurement and implantation; (3) acute graft failure is more common with lungs than other solid organs, thus contributing to poorer short-term survival after lung transplant compared with that for recipients of other organs; (4) lung transplant recipients are particularly vulnerable to pulmonary infections; and (5) chronic allograft dysfunction, manifest by bronchiolitis obliterans syndrome, is frequent and limits long-term survival. Scientific advances may provide significant improvements in the outcome of lung transplantation. The National Heart, Lung, and Blood Institute convened a working group of investigators on June 14-15, 2004, in Bethesda, Maryland, to identify opportunities for scientific advancement in lung transplantation, including basic and clinical research. This workshop provides a framework to identify critical issues related to clinical lung transplantation, and to delineate important areas for productive scientific investigation.

Equivalence of Flow Velocities Through Bilateral Pulmonary Vein Anastomoses in Bilateral Living-Donor Lobar Lung Transplantation

BACKGROUND

Intraoperative transesophageal echocardiography (TEE) during lung transplantation is useful for monitoring cardiac condition and pulmonary vascular anastomoses to detect vascular complications, but the parameters for evaluation by TEE during lung transplantation have not been established.

METHODS

We performed intraoperative TEE on 17 patients during living-donor lobar lung transplantation (LDLLT) and investigated the usefulness of measurement of peak flow velocities through bilateral pulmonary vein (PV) anastomoses and evaluation of the equivalence.

RESULTS

The peak flow velocities through bilateral PV anastomoses were almost equivalent in 14 patients without complications and were not equivalent in 3 patients with complications such as vascular stenosis and peripheral atelectasis.

CONCLUSIONS

The flow velocities through the bilateral PV anastomoses are shown to be nearly equivalent during bilateral LDLLT, and the equivalence may be one factor for predicting the success of LDLLT.

Use of Lung Transplantation Survival Models to Refine Patient Selection in Cystic Fibrosis

Lung transplantation in cystic fibrosis may improve survival for patients with low 5-year predicted survival. Identifying characteristics that affect post-transplantation survival may improve patient selection and survival benefit. Using Cystic Fibrosis Foundation Patient Registry and United Network for Organ Sharing data, we identified 845 lung transplant recipients from 1991-2001, and 12,826 control patients from 1997. We used Cox proportional hazards models to identify variables that influence post-transplantation survival. To estimate the survival benefit of transplantation for patients affected by identified variables, we compared Kaplan-Meier survival curves of transplanted and control patients stratified by 5-year predicted survival. Post-transplantation survival improved annually. Youth, Burkholderia cepacia, and cystic fibrosis-related arthropathy increased the post-transplantation hazard of death. Compared with control subjects, transplanted adults with a 5-year predicted survival of less than 50% without B. cepacia or arthropathy have improved survival. Transplanted adults with B. cepacia, arthropathy, or a 5-year predicted survival of greater than 50% have decreased survival. Transplantation never improves survivorship for pediatric patients. Patients with arthropathy, B. cepacia infection, or younger age derive no aggregate survival benefit and must appraise carefully the high risk of decreased post-transplantation survival. Adult patients with low 5-year predicted survival without B. cepacia infection should receive priority for lung transplantation.

Effects of postmortem heparinization in canine lung transplantation with non–heart-beating donors

OBJECTIVE

Microthrombus formation appears to be one of the major detrimental factors in lung transplantation from non-heart-beating donors. The purpose of this study was to evaluate the effects of postmortem heparinization by closed-chest cardiac massage in a canine model of left single-lung allotransplantation from non-heart-beating donors.

METHODS

Left lung transplantation was performed in 18 weight-matched pairs of mongrel dogs. Donors were killed with an intravenous injection of potassium chloride and left at room temperature for 2 hours. The cadaveric donors were assigned randomly to one of the three groups. In group 1 (n = 6), no heparin was given as a control. In group 2 (n = 6), heparin sodium (1000 U/kg) was administered intravenously before cardiac arrest. In group 3 (n = 6), heparin sodium (1000 U/kg) was administered intravenously 10 minutes after death, then closed-chest cardiac massage was performed for 2 minutes. After 2 hours of cardiac arrest, donor lungs were flushed with low-potassium dextran-glucose solution and preserved for 60 minutes. After left lung transplantation, the right pulmonary artery was ligated, and recipient animals were followed up for 3 hours. Univariate and multivariate repeated analyses were used for statistics.

RESULTS

Both groups 2 and 3 had significantly better gas exchange and lower pulmonary vascular resistance than group 1. Changes in thrombin-antithrombin III complex concentration during the warm ischemia indicated that postmortem heparinization suppressed clotting activation in the donor.

CONCLUSIONS

Postmortem heparinization by cardiac massage is beneficial in lung transplantation from non-heart beating donors by preventing microthrombus formation.

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.

Bilateral living-donor lobar lung transplantation

Bilateral living-donor lobar lung transplantation is a procedure for patients considered too ill to await cadaveric transplantation. In this relatively new procedure, right and left lower lobes from two healthy donors are implanted in the recipient in place of the whole right and left lungs, respectively. The surgical aspects of the right and left donor lobectomy, the donor lobe back-table preservation technique, and the recipient bilateral pneumonectomy and bilateral lobar implantation under cardiopulmonary bypass are shown.

Lung transplantation for interstitial lung disease

Lung transplantation remains the only therapeutic option shown to improve survival for many end-stage interstitial lung diseases. Although idiopathic pulmonary fibrosis is the most common indication, transplantation has been performed for many other diseases. This article reviews the current indications and outcomes for the procedure and problems encountered in lung transplantation for interstitial lung diseases. The role of transplant for specific diseases also is discussed.

Improved survival after living-donor lobar lung transplantation

OBJECTIVE

Survival after living-donor lobar lung transplantation has been reported to be similar to that after cadaveric lung transplantation. The purpose of this study was to summarize our 5-year experience of living-donor lobar lung transplantation for critically ill patients.

METHODS

Between October 1998 and April 2004, we performed living-donor lobar lung transplantation in 30 critically ill patients with various lung diseases, including 5 (17%) patients on a ventilator. Mean age was 30.4 years (range, 8-55 years). Postoperative management included slow weaning from a ventilator, relatively low-dose immunosuppressants, and careful rejection monitoring on the basis of radiographic and clinical findings without transbronchial lung biopsy.

RESULTS

The average duration of mechanical ventilation was 15.4 days, intensive care unit stay was 23.5 days, and hospital stay was 64.6 days. Clinically judged acute rejection occurred at an average rate of 1.5 episodes per patient, but infection occurred in only one patient during the first month. In spite of the complicated postoperative course, all patients were discharged without oxygen inhalation. Four patients had unilateral bronchiolitis obliterans syndrome, but the decrease in their forced expiratory volume in 1 second values stopped within 9 months. All 30 recipients are currently alive, with a follow-up period of 1 to 66 months. All donors have returned to their previous lifestyles.

CONCLUSIONS

Living-donor lobar lung transplantation can be applied to both pediatric and adult patients with very limited life expectancies. It might provide better survival than conventional cadaveric lung transplantation.

A decade of living lobar lung transplantation: perioperative complications after 253 donor lobectomies

Living lobar lung transplantation places two donors at risk for each recipient. We examined the perioperative outcomes associated with the 253 donor lobectomies performed at our institution during our first decade of living lobar lung transplantation. There have been no perioperative or long-term deaths. 80.2% of donors (n = 203) had no perioperative complications, while fifty (19.8%) had one or more complication. The incidence of intraoperative complications was 3.6%. Complications requiring reoperation occurred in 3.2% of donors. 15.0% of donors had other perioperative complications; the most serious were two donors who developed pulmonary artery thrombosis, while the most common was the need for an additional thoracostomy tube or a thoracostomy tube for >/=14 d for persistent air leaks and/or drainage. Right-sided donors were more likely to have a perioperative complication than left-sided donors (odd ratio 2.02, p = 0.04), probably secondary to right lower and middle lobe anatomy. This experience has shown donor lobectomy to be associated with a relatively low morbidity and no mortality, and is important if this procedure is to be considered an option at more pulmonary transplant centers, given continued organ shortages and differences in philosophical and ethical acceptance of live

Management of an ABO-incompatible lung transplant

A 24-year-old woman with cystic fibrosis underwent bilateral sequential lung transplantation and unintentionally received an ABO incompatible graft (blood type A(1) graft into a type O recipient). The recipient had a high titer of IgG anti-A antibody (256 by the indirect antiglobulin test). Emergency treatment included antibody removal by plasmapheresis and additional immunosuppression with mycophenolate, rabbit antithymocyte globulin and polyspecific intravenous immunoglobulin. Subsequently, immunoadsorption and the anti-CD20 antibody rituximab were used to remove anti-A antibody and inhibit its resynthesis. Early graft function was good; one episode of rejection at Day 46 responded promptly to treatment with methylprednisolone. Subsequently, graft function continued to improve and anti-A antibody titers remained low. No infectious or other complications were encountered. The treatment regimen that we adopted may prove useful in other cases of unplanned ABO-incompatible organ transplants. The successful outcome suggests that planned ABO-incompatible lung transplants may be possible.

Anastomosis of an anomalous segmental vein with the azygos vein in living-donor lobar lung transplantation

We report the case of a living-donor lobar lung transplantation in which we found an abnormal segmental vein in the right lower lobe of the donor lung. The abnormal vein was anastomosed to the azygos vein of the recipient so that lung edema and congestion could be avoided. This alternative technique is effective in living-donor lobar lung transplantation when the superior segmental vein in the right lower lobe of the donor drains into the superior vein.

How to predict forced vital capacity after living-donor lobar-lung transplantation

BACKGROUND

Living-donor lobar-lung transplantation (LDLLT) has evolved from a rarely performed experimental procedure to an accepted therapy for selected patients who are unlikely to survive the long wait for cadaveric lungs. However, a convincing study has not been performed that shows the effects of small grafts and of pre-operative variables in predicting functional outcome of recipients after LDLLT.

METHODS

From October 1998 to March 2002, 2 male and 11 female patients underwent LDLLT. Mean age was 27.3 years (range, 8-53 years). Diagnoses included primary pulmonary hypertension (n = 5), idiopathic interstitial pneumonia (n = 2), bronchiolitis obliterans (n = 2), bronchiectasis (n = 2), lymphangioleiomyomatosis (n = 1), and cystic fibrosis (n = 1). Donors included 12 men and 14 women with a mean age of 40 years. Given that the right lower lobe consists of 5 segments, the left lower lobe of 4, and the whole lung of 19, we estimated the graft forced vital capacity (FVC) based on the donor's measured FVC and compared this with the recipient's FVC measured after LDLLT.

RESULTS

Currently, all patients are alive, with a mean follow-up of 22.2 months (range, 10-51 months). The recipients' FVC measured at 6 months (1,813 +/- 86 ml) correlated well with the graft FVC (1,803 +/- 70 ml), estimated based on the donors' measured FVC (r = 0.802, p = 0.00098).

CONCLUSIONS

Recipient FVC after LDLLT can be predicted by measuring donor FVC before surgery regardless of the diagnosis of the 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.

Experience with cyclosporine in living-donor lobar lung transplantation

Living-donor lobar lung transplantation is an alternative to conventional cadaveric lung transplantation for both pediatric and adult patients. In 16 patients, postoperative immunosuppression included cyclosporine, azathioprine, and corticosteroids. Cyclosporine delivery began during the first few postoperative hours via a nasal feeding tube inserted to the proximal jejunum. The dosage was adjusted to maintain trough levels in the target range of 250 to 350 ng/dL during the first 3 months; however, it was often reduced when renal dysfunction was suspected. We judged acute rejection on the basis of radiographic and clinical findings without lung biopsy. During the first month, 15 of 16 patients experienced at least one episode of acute rejection with an average of 1.7 episodes/patient. Cyclosporine was switched to tacrolimus in four patients (25%) due to repeated episodes of acute rejection. No patients experienced infectious complications during the first months. All 16 patients are currently alive with a follow-up period of 3 to 59 months. Three patients (19%) have developed unilateral bronchiolitis obliterans. Cyclosporine-based immunosuppression can be safely given to the recipients of LDLLT without significant adverse effects but the incidence of acute rejection is relatively high. The optimal long-term immunosuppressive regimen remains to be established.

The technique of unilateral double lobar lung transplantation in a canine model

OBJECTIVE

Bilateral living-donor lobar lung transplantation has become an accepted alternative to cadaveric lung transplantation. Because only one lobe is implanted in each chest cavity, this procedure seems to be best suited for children and small adults. The purpose of this study was to develop a technique of unilateral double lobar lung transplantation that can be applied to large adult patients.

METHODS

Unilateral double lobar lung transplantation was performed in 6 weight-matched pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the right hemithorax after right pneumonectomy. The left graft was implanted as a right upper lobe, having been rotated 180 degrees along the vertical axis and then 180 degrees along the horizontal axis. The right graft was implanted in the natural anatomic position. Function of the transplanted grafts was assessed for 3 hours after ligation of the left main pulmonary artery while the animals were ventilated with 100% oxygen.

RESULTS

Morphologic adaptation of the 2 grafts in the right hemithorax was found to be excellent. All 6 animals survived the assessment period with excellent pulmonary function. At the end of the 3-hour assessment period, the arterial oxygen tension was 519 +/- 31 mm Hg, and the mean pulmonary artery pressure was 30.5 +/- 1.7 mm Hg.

CONCLUSIONS

Unilateral double lobar lung transplantation was technically possible and associated with satisfactory early pulmonary function in a canine experimental model.

Non-heart-beating donors in thoracic transplantation

Access to lung transplantation is severely limited by a scarcity of suitable donors, resulting in increasing numbers of deaths on the heart and lung transplant waiting lists, and strict selection criteria for recipients. Unlike some other solid organs, the lung may be ideally suited to retrieval for transplant following substantial intervals after circulatory arrest. This may be because lung parenchymal cells do not rely on perfusion for cellular respiration. This review outlines the relevant published experimental data that addresses the concept that lungs might be suitable for transplant even if retrieved from non-heart-beating donors (NHBDs), and the small published clinical experience with NHBDs as lung donors. Aspects of reperfusion injury in this setting are reviewed. The prospect of heart transplant from NHBDs is addressed. The impact of the routine use of NHBDs on lung transplantation is discussed.

Technical considerations in lung transplantation

The technical aspects of lung transplantation have been refined over the past two decades. Anomalous donor anatomy and suboptimal harvests do not preclude transplantation, but they must be appropriately dealt with to ensure good outcomes. New techniques have been developed to increase the donor pool. Techniques for recipient pneumonectomy and graft implantation have been optimized, and ways of dealing with difficult exposures and anatomic variants have been designed. Novel methods for prevention of ischemia-reperfusion injury have been developed based on experimental studies, but more complete clinical scrutiny is needed to determine their impact.

Living-donor lobar lung transplantation for various lung diseases

OBJECTIVE

We report on our early experience in living-donor lobar lung transplantation for patients with various lung diseases including restrictive, obstructive, septic, and hypertensive lung diseases.

METHODS

From October 1998 to March 2002, living-donor lobar lung transplantation was performed in 14 patients with end-stage lung diseases. There were 11 female patients and 3 male patients, with ages ranging from 8 to 53 years, including 4 children and 10 adults. Diagnoses included primary pulmonary hypertension (n = 6), idiopathic interstitial pneumonia (n = 2), bronchiolitis obliterans (n = 2), bronchiectasis (n = 2), lymphangioleiomyomatosis (n = 1), and cystic fibrosis (n = 1). Bilateral living-donor lobar lung transplantation was performed in 13 patients and right single living-donor lobar lung transplantation was performed for a 10-year-old boy with primary pulmonary hypertension.

RESULTS

All the 14 patients are currently alive with a follow-up period of 4 to 45 months. Although their forced vital capacity (1327 +/- 78 mL, 50.2% of predicted) was limited at discharge, arterial oxygen tension on room air (98.5 +/- 1.8 mm Hg) and systolic pulmonary artery pressure (24.8 +/- 1.6 mm Hg) were excellent. Forced vital capacity improved gradually and reached 1894 +/- 99 mL, 67.4% of predicted, at 1 year. All donors have returned to their previous lifestyles.

CONCLUSIONS

Living-donor lobar lung transplantation can be applied to restrictive, obstructive, septic, and hypertensive lung diseases. This type of procedure can be an alternative to conventional cadaveric lung transplantation for both pediatric and adult patients who would die soon otherwise.

Living lobar transplantation

Although cadaveric transplantation remains the preferred option for patients who have end-stage lung disease, living lobar transplantation provides organ availability that can be life saving in severely ill pediatric and adult patients who will either die or become unsuitable recipients before a cadaveric organ becomes available. In addition, living lobar transplantation provides acceptable long-term survival when compared with recipients of cadaveric grafts; however, because this procedure presents risks to two healthy donors, appropriate recipient and donor selection and timing of transplantation are critical to minimize the morbidity to the donor and maximize the chance of a successful outcome in the recipient. The results of the authors' experience have demonstrated that the donor procedure is safe, well tolerated physiologically, and that the great majority of donors are extremely satisfied with their decision to donate. Although there have been no deaths in the donor cohort, a risk of death between 0.5% to 1% should be quoted pending further data. These encouraging results are important if this procedure is to be considered as an option at more pulmonary transplant centers in view of the institutional, regional, and intra- and international differences in the philosophical and ethical acceptance of the use of live organ donors for transplantation.

Selection of patients with cystic fibrosis for lung transplantation

Lung transplantation is the most aggressive therapy available for end-stage lung disease from cystic fibrosis (CF). A new predictive survival model of CF uses demographic, FEV1, nutritional, microbiologic, and acute exacerbation data to produce precise estimates of 5-year survival. The model improves the ability to select patients most likely to have survival benefit from transplantation. We discuss potential application of the survival model to four distinct groups of patients with CF: (1) candidates for cadaveric transplantation, (2) potential living donor recipients, (3) patients infected with multiply-resistant organisms such as Burkholderia cepacia, and (4) patients critically ill and dependent on mechanical ventilation. Measuring the impact of transplantation on quality of life remains a difficult task, and further studies are needed to determine whether lung-transplantation-derived survival benefit implies quality-of-life benefit. However, judicious use of the survival model to select patients for transplantation is likely to improve survival outcomes.

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.

Attitudes regarding organ donation from non-heart-beating donors

PURPOSE

To determine the attitudes toward organ donation from non-heart-beating cadaver donors in a sample of the general public and health care workers.

MATERIALS AND METHODS

A moderator-administered questionnaire was completed by members of the general public, recruited randomly from a professional consumer research group's database, and health care workers recruited from the same database, family practice clinics, and local hospitals. Two primary scenarios were tested: (1) patient in coma, not going to survive intensive care unit (ICU), and (2) patient lapsing in and out of consciousness, lifetime institutional care.

RESULTS

Sixty members of the general public and 68 health care workers completed the questionnaire. The majority of both groups were aware life support could be withdrawn in Scenario 1, however, significantly fewer were aware life support could also be withdrawn in Scenario 2 (83% general public vs 34% general public, P <.001 and 94% health care workers vs 78% health care workers, P =.012). Uncertainty in prognosis was cited as the primary concern. The issue of organ donation was directly linked with withdrawal of life support. The majority of both groups believed that organ donation would be permissible if further life support were deemed to be not in the patient's best interest because of poor short-term prognosis (94% health care workers and 98% general public for Scenario 1 and 87% health care workers and 81% general public for Scenario 2). The greatest difficulty arose in defining futility of care. Expected quality of life, patient's and family's values, opinions, and religious beliefs were felt to be most important in determining decisions regarding futility and withdrawal of life support. Physician beliefs and values were felt to influence decisions more than they should.

CONCLUSIONS

Both the general public and health care workers support the use of non-heart-beating cadaver donors once a decision has been made to withdraw life support. However, both groups raised concerns regarding how the decision to withdraw life support is made.

Contrasting natures of lung growth after transplantation and lobectomy

OBJECTIVE

We hypothesized that posttransplantation lung growth in an immature recipient and postlobectomy compensatory lung growth are two distinct processes.

METHODS

Mature swine underwent left upper lobectomy, and growth of the left lower lobe was studied after 2 weeks and after 3 months. Left lower lobes from another set of mature pigs were transplanted into immature animals, and growth of the transplanted lobe was then studied after 2 weeks and after 3 months. Left lower lobes from mature animals that did not undergo operation were used as normal control lobes. The lobes were weighed on removal and fixed intrabronchially. Sections stained with hematoxylin and eosin were used to determine alveolar surface density and percentage volume of respiratory region. Immunostaining for 5-bromo-2'-deoxyuridine was used to determine alveolar cell proliferation index, and epidermal growth factor receptor expression was detected by Western blot.

RESULTS

Postlobectomy lung growth (increase in lobe weight) reached statistical significance at 2 weeks, with a concomitant rise in cell proliferation index. The transplanted lobe, in contrast, exhibited a gradual growth response, with a statistically significant increase in cell proliferation index at 3 months. Volume of respiratory region was noted to increase only in the transplanted lobe at 3 months. Epidermal growth factor receptor expression was upwardly regulated relative to that in normal control lobes in the 2-week postlobectomy and 3-month posttransplantation lobes.

CONCLUSIONS

Postlobectomy lung growth appears to be regulated by a different mechanism than is posttransplantation lung growth and is a more rapid and restorative process. The growth peaks in both processes correlate with upward regulation of cell proliferation index and epidermal growth factor receptor expression.

Intrathoracic cooling of cadavers before lung transplantation using cold air: an experimental study

OBJECTIVE

In an attempt to identify an effective method of harvesting adequately functioning donor lungs from a cadaver, we devised an intrathoracic cooling method utilizing cold air that resulted in successful experimental lung transplantation.

METHODS

The lungs of donor mongrel dogs were inflated with 100% oxygen after death. The animals in group I (n=5) were left at room temperature for 2 hr, whereas those in group II (n=5) were left for 2 hr with their left thoraces filled with cold air cooled by dry ice. The lungs were subsequently flushed with cold Euro-Collins solution, harvested, and stored inflated in a cold saline solution for a further 2 hr. Left lung allotransplantation was then performed. Transplanted left lung function was examined by inducing occlusion of the native right bronchus and pulmonary artery for 10 min while the left lung was ventilated with 100% oxygen.

RESULTS

There was a slow decline in intrathoracic, lung surface, and endobronchial temperatures toward room temperature in group I. In contrast, all three temperatures dropped to approximately 10 degrees C within 30 min in group II. In group I, all recipient dogs died immediately after occlusion was induced, whereas four of the five dogs in group II survived to show satisfactory lung function.

CONCLUSIONS

(1) Intrathoracic topical cooling of a cadaver by cold air is efficacious in decreasing lung temperature and thus preserving lung tissue function. (2) Transplantation of cadaver lungs harvested using this novel method might be clinically feasible.

Experimental study on size matching in a canine living-donor lobar lung transplant model

OBJECTIVE

In an effort to address the donor-shortage issue, living-donor lobar lung transplants have been performed with satisfactory results. The use of small grafts is potentially problematic because it could cause high pulmonary artery pressure, resulting in lung edema. The purpose of this study was to evaluate the effect of small grafts on early pulmonary function and to identify the predictor for acceptable size discrepancy.

METHODS

Seventeen pairs of mongrel dogs with various donor-recipient sizes were used. Body weight, height, chest circumference, and lung weight were measured as size parameters. Right middle, lower, and cardiac lobes were implanted as a right lung of the recipient and the left lower lobe was implanted as a left lung without use of cardiopulmonary bypass. Pulmonary function of the recipient was measured for 6 hours after reperfusion.

RESULTS

A significant negative correlation was found between donor/recipient body-weight ratio and mean pulmonary artery pressure at 1 hour (r = -0.594, P =.025). A significant correlation was found between donor/recipient body-weight ratio and PaO(2) at 6 hours (r = 0.704; P =.007). There was no significant correlation between the other 3 size parameters and postoperative pulmonary function. All 8 recipients with a donor/recipient body-weight ratio of 1.2 or greater survived the 6-hour assessment period, and their PaO(2) exceeded 500 mm Hg at 6 hours.

CONCLUSIONS

Donor/recipient weight ratio is an important predictor of early pulmonary function in a canine living-donor lobar lung transplant model.

Survival effect of lung transplantation among patients with cystic fibrosis

CONTEXT

Patients with cystic fibrosis (CF) are the second largest group of lung transplant recipients in the United States. The survival effect of transplantation on a general CF population has not previously been measured.

OBJECTIVE

To determine the impact of bilateral lung transplantation on survival in patients with CF.

DESIGN, SETTING, AND PATIENTS

Retrospective observational cohort study of 11 630 CF patients who did not undergo lung transplantation (controls) and 468 transplant recipients with CF from 115 CF centers in the United States, 1992-1998. Patients were stratified into 5 groups based on a 5-year survival prediction model (survival group 1: <30%; survival group 2: 30 to <50%; survival groups 3-5: 50 to <100%.)

MAIN OUTCOME MEASURE

Five-year survival from date of transplantation in 1992-1997 in the transplant group and from January 1, 1993, in the control group.

RESULTS

Lung transplantation increased 5-year survival of CF patients in survival group 1. Survival group 2 had equivocal survival effects, and groups 3-5 had negative survival effects from transplantation. From 1994-1997, there was a mean annual prevalence of 238 patients in survival group 1 and mean annual incidence of 154 patients entering the group, approximately 1.5 times the number of lung transplantations performed each year in CF patients (mean, 104). Use of the criterion of forced expiratory volume in 1 second of less than 30% resulted in an equivocal survival benefit and identified 1458 potential candidates for transplantation in 1993.

CONCLUSIONS

Cystic fibrosis patients in group 1 have improved 5-year survival after lung transplantation. The majority of patients with CF have equivocal or negative survival effects from the procedure. Selection of patients with CF for transplantation based on group 1 survival predictions maximizes survival benefits to individuals and may reduce the demand for scarce donor organs.

Experimental study of oversized grafts in a canine living-donor lobar lung transplantation model

BACKGROUND

For infants and small children, organ transplantation is limited by the size discrepancy between donor and recipient. To address this problem, the use of over-sized grafts from living-relative donors could potentially expand the donor pool. The aim of this experimental study was to evaluate the effect of oversized grafts on early pulmonary function and to identify an indicator for acceptable size discrepancy.

METHODS

Fourteen bilateral lobar lung allotransplant operations were performed without cardiopulmonary bypass in weight mismatched pairs of dogs. Animals were divided into 2 groups: Group I (n = 7), donor/recipient lung volume ratio < 2.85; Group II (n = 7), donor/recipient lung volume ratio >2.85. Pulmonary function of the recipient was measured before chest closure, after chest closure, and after the ventilator was removed.

RESULTS

Pulmonary vascular resistance and airway pressure significantly increased in Group II after chest closure (1493 +/- 195 dynes sec cm(-5) and 14.4 +/- 0.9 mm Hg vs 2784 +/- 140 dynes sec cm(-5) and 23.4 +/- 1.2 mm Hg, p < 0.001). After the ventilator was removed, all recipients in Group I showed PaO2 > 239 mm Hg and PaCO2 < 76 mm Hg, whereas, all recipients in Group II showed PaO2 < 116 mm Hg and PaCO2 > 169 mm Hg. The donor/recipient chest circumference ratio was less than 1.3 in all but 1 dog in Group I.

CONCLUSIONS

Acceptable, oversized grafts provide adequate pulmonary function, although excessively oversized grafts cause significant impairment in pulmonary function after chest closure. Chest circumference provides useful size-match criteria when oversized grafts are used in this canine experimental model.

Living-donor lobar lung transplantation for primary ciliary dyskinesia

A ventilator-dependent patient with primary ciliary dyskinesia underwent successful living-donor lobar lung transplantation. The case was a 24-year-old woman who had developed recurrent lower respiratory infection and became ventilator-dependent due to severe bronchiectasis. Transmission electron microscopy of the resected bronchus demonstrated inner dynein arm deficiency.

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

BACKGROUND

Obliterative bronchiolitis (OB) is the chief cause of mortality in cadaveric lung transplant patients (CL). But, is OB the primary cause of mortality for living donor lobar recipients? To answer this question, we reviewed the causes of mortality in our pediatric patients who underwent living donor lobar lung transplantation (LD) and compared them with our pediatric patients who received whole cadaveric lungs (CL).

METHODS

Data collected included demographics, transplant type, hospital days, immunosuppression regimen, and cause of death. Statistical analysis was done using Fisher's Exact test and Student's t-test (mean +/- SD).

RESULTS

From May 1993 to December 1999, 53 patients underwent lung transplantation (21 males, 32 females; mean age 12.4 +/- 5.4 years). Twenty-nine patients had LD procedures (12 males, 17 females; mean age 14.4 +/- 3.6 years) and 24 patients had CL surgery (9 males, 15 females; p = .78 [not significant]; mean age 9.8 +/- 6.3 years; p =.001). All patients received triple immunosuppression without induction. During the study period, 9 LD (6 males, 3 females; mean age 15.7 +/- 5.0 years) and 14 CL (3 males, 11 females; mean age 11.3 +/- 6.9 years) patients died. There was no significant difference between patients in the LD and CL groups who died with regard to gender (p = .08), age at the time of death (p = .12), mortality rate (p = .06), number of hospital days (p = .09), immunosuppressive medications (p > .08), incidence of non-specific graft failure (p = .26), or incidence of infection (p = .18). However, there was a significant difference in the incidence of OB between LD and CL recipients (p = .002).

CONCLUSIONS

OB was not found to be the chief cause of mortality in pediatric LD recipients. We speculate that prevention of infections, possibly by a modest reduction in immunosuppressive therapy and aggressive antimicrobial therapy, may improve long-term survival in pediatric living donor lobar lung transplant recipients.

Inhaled nitric oxide ameliorates postoperative acute graft dysfunction after living-donor lobar lung transplantation

Inhaled nitric oxide, a selective pulmonary vasodilator, decreases mean pulmonary artery pressure and pulmonary vascular resistance and improves oxygenation in previously unobtainable ways without significant changes in systemic hemodynamics. We report successful treatment of a patient with acute graft dysfunction after living-donor lobar lung transplantation using nitric oxide inhalation.