Experience with pediatric lung transplantation

Long-term outcomes of patients with pulmonary arteriovenous malformations considered for lung transplantation, compared with similarly hypoxaemic cohorts

INTRODUCTION

Pulmonary arteriovenous malformations (PAVMs) may not be amenable to treatment by embolisation or surgical resection, and many patients are left with significant hypoxaemia. Lung transplantation has been undertaken. There is no guidance on selection criteria.

METHODS

To guide transplantation listing assessments, the outcomes of the six patients who had been considered for transplantation were compared with a similarly hypoxaemic patient group recruited prospectively between 2005 and 2016 at the same UK institution.

RESULTS

Six patients had been formally considered for lung transplantation purely for PAVMs. One underwent a single lung transplantation for diffuse PAVMs and died within 4 weeks of surgery. The other five were not transplanted, in four cases at the patients' request. Their current survival ranges from 16 to 27 (median 21) years post-transplant assessment. Of 444 consecutive patients with PAVMs recruited between 2005 and 2016, 42 were similarly hypoxaemic to the 'transplant-considered' cohort (SaO2 <86.5%). Hypoxaemic cohorts maintained arterial oxygen content (CaO2) through secondary erythrocytosis and higher haemoglobin. The 'transplant-considered' cohort had similar CaO2 to the hypoxaemic comparator group, but higher Medical Research Council (MRC) dyspnoea scores (p=0.023), higher rates of cerebral abscesses (p=0.0043) and higher rates of venous thromboemboli (p=0.0009) that were evident before and after the decision to list for transplantation.

CONCLUSIONS

The non-transplanted patients demonstrated marked longevity. Symptoms and comorbidities were better predictors of health than oxygen measurements. While a case-by-case decision, weighing survival estimates and quality of life will help patients in their decision making, the data suggest a very strong case must be made before lung transplantation is considered.

Mortality after pediatric lung transplantation: autopsies vs. clinical impression

Appreciable mortality accompanies pediatric lung and heart-lung transplantation. The objective of this investigation was to compare the clinical impression of causes of death with autopsy findings in all pediatric lung or heart lung transplant recipients who had an autopsy performed between 1985-2002 at the Children's Hospital of Pittsburgh. Medical records and autopsy findings were reviewed. Thirty recipients with autopsies had 33 transplant procedures: heart-lung (16), double lung (14), repeat lung (2), and repeat heart-lung (1). Perioperative deaths occurred in 8 children, most often precipitated by graft dysfunction. Early deaths (2 weeks-1 year) occurred in 12 children resulting from infection. Late deaths (greater than 1 year) occurred in 10 children. Bronchiolitis obliterans complicated by infection was the major cause of death in these recipients. An autopsy confirmed the clinical impression of cause of death in 29/30 and added significant supplemental information in 16 cases. Unsuspected factors contributing to death included donor lung abnormalities, concurrent infection, and cardiovascular disease. Postmortem examination remains a critical component to augment the understanding of causes of death following pediatric thoracic transplantation.

Burkholderia cepacia complex: a contraindication to lung transplantation in cystic fibrosis?

Previous studies have indicated that pulmonary infection with Burkholderia cepacia is associated with poor clinical outcome after lung transplantation in cystic fibrosis (CF). Many treatment centers consider B. cepacia infection an absolute contraindication to lung transplantation. However, the B. cepacia complex actually consists of several closely related bacterial species. Although each of these has been isolated from CF sputum culture, certain species are much more frequently recovered than others, and it is not yet clear whether all species have the same potential for virulence in CF. Additional study is needed to better define the relative risks associated with each species of the B. cepacia complex.

Airway complications following pediatric lung and heart-lung transplantation

Obstruction at the airway anastomosis is a recognized complication of adult heart-lung transplantation (HLT) and lung transplantation (LT). Data for pediatric transplantation have been scarce. We reviewed our experience in pediatric HLT and LT to determine the frequency of airway complications and to document the therapeutic modalities used for their treatment. Fifty-three patients (median age: 13.8 yr; range: 1.3 to 28.2 yr) underwent HLT (n = 25), SLT (n = 3), DLT (n = 25), or repeat DLT (n = 3) and survived for more than 72 h. Major anastomotic airway complications requiring intervention affected one of the 25 HLT (4%) and seven of the 28 LT (SLT + DLT) patients (25%) (p = 0.05). Four patients with granulation tissue occluding the airway were treated with forceps resection, laser ablation, or balloon dilatation. Three patients with fibrotic strictures received silicone stents, laser ablation, or balloon dilatation. Two patients with bronchomalacia or diffuse stricture below the anastomosis underwent metal stent placement. Five of seven patients who were treated for anastomotic complications had satisfactory relief of airway obstruction. As compared with previously studied adults, pediatric heart-lung transplant recipients had the same or a lower frequency, and pediatric lung transplant recipients had a higher frequency of major anastomotic airway complications. A variety of treatment modalities were necessary to achieve adequate relief of airway obstruction.

Kidney function in cyclosporine-treated paediatric pulmonary transplant recipients

BACKGROUND

Lung or heart-lung transplantation is a useful therapy in life-threatening pulmonary disorders during childhood. Cyclosporine A is a major immunosuppressive treatment but has a number of adverse effects including nephrotoxicity. There have been no reports on the long-term evolution of renal function in a large series of paediatric pulmonary transplantation recipients.

METHODS

We examined 19 patients followed up for at least 3 years after pulmonary transplantation. The mean time of follow-up was 5.36 years. Kidney function was evaluated by calculation of glomerular filtration rate (GFR) according the Schwartz formula.

RESULTS

The GFR was normal before transplantation in all patients. The short-term evolution of GFR was marked by a significant drop during the first and until the 6th month. Then, regardless of the level reached at the end of the 6th month, the GFR remained stable in all patients except one until the end of follow-up. At the end of follow-up, 31% had normal GFR, 57% had mild chronic renal failure, and 5% had advanced renal failure. Hypertension was frequent and associated with renal failure.

CONCLUSIONS

Paediatric pulmonary recipients showed evidence of long-term cyclosporine A-associated nephrotoxicity. Most of this toxicity occurred during the first 6 months.

Congenital Heart Surgery Nomenclature and Database Project: end-stage lung disease

The extant nomenclature for end-stage lung disease is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories, using synonyms where appropriate. Indications for lung transplantation are coded under a broad category called pulmonary failure. The proposed hierarchical scheme also allows classification of complications of lung transplantation under a category called status post lung transplant. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail, which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented, which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Radionuclide imaging of acute lung transplant rejection with annexin V

STUDY OBJECTIVES

Early detection and treatment of lung transplant rejection is critical for preservation of pulmonary graft function. Damage to pulmonary allografts is mediated by apoptotic cell death induced by the alloreactive T lymphocytes that infiltrate lung grafts. Previous studies demonstrate that acute cardiac allograft rejection can be visualized using radiolabeled annexin V. This study was done to determine whether this technique could visualize acute rejection in a rodent model of unilateral orthotopic lung transplantation.

DESIGN

Eighteen Sprague-Dawley ACI rats underwent removal of their left lung followed by orthotopic transplant of either an allogeneic (PVG, immunologically mismatched; N = 10) or a syngeneic (ACI, immunologically matched) pulmonary graft (N = 8). Animals were imaged 1 h after IV injection of 1 mCi (37.0 MBq) of (99m)Tc-annexin V 1 to 7 days after transplantation.

RESULTS

Lungs receiving the allograft demonstrated moderate to marked mononuclear infiltration of the perivascular, interstitial, and peribronchial tissues. No mononuclear infiltrates were noted in the native right lungs nor in the syngeneic transplants. Region of interest image analysis revealed significant (p < 0.0005) increases of transplant to normal lung activity ratios 3 to 7 days after allograft surgery. The increased annexin V uptake in these lungs was confirmed at biodistribution assay (allograft 151% greater than isograft activity, p < 0.005).

CONCLUSIONS

Acute experimental lung transplant rejection can be noninvasively identified using (99m)Tc-annexin V. Radiolabeled annexin V may be a clinically useful noninvasive screening tool for acute rejection.

Lung infections in pediatric lung transplantation: experience in 49 cases

OBJECTIVES

Pulmonary infections, and particularly cytomegalovirus (CMV) infections, are a major cause of morbidity after lung transplantation. We report here our results in 49 pediatric lung transplantations.

METHODS

Between may 1988 and 1997, we have done 49 lung transplantations in 42 children (en bloc double lung transplantation (DLT):10, HLTx:7, sequential bilateral sequential-lung transplantation (BSLT):31, single-lung transplantation (SLT): 1). In seven, it was a retransplantation. Among these, 34 were cystic fibrosis (CF) patients, all with multiresistant organisms (Pseudomonas aeruginosa, Burkholderia cepacia, Achromobacter xylososydans, Staphylococcus aureus). All patients were treated with multiantibiotic prophylaxy adapted to the preoperative cultures. Donor-recipient CMV matching was possible in only 31 cases. CMV prophylaxy and immunosuppression protocols have evolved with time, with a current protocol of IV Gancyclovir prophylaxy for 3 months and triple drug immunosuppression without post-operative rabbit anti-thymocyte globulin (RATG) induction. There was no perioperative mortality in the primary transplantations and three early deaths in the whole group (6.1%).

RESULTS

Only five patients had no pulmonary infection. The patients presented 3.2 infection episodes per year, 75% localized on the lungs, 41% during the first 3 months. Among the 13 deaths in the 1st year, 10 were directly related to infection, 60% due to CMV. After the 1st year, in all patients dying of pulmonary dysfunction or obliterative bronchiolitis (OB), bacterial infections were associated. There was no serious fungal infection. Actuarial survival at 3 months, 1, 3, 5 years were 85, 65.7, 47.5 and 28.5%, respectively. There was a significant difference in 3 year survival between patients receiving CMV negative organs (40%) and CMV positive organs (17%).

CONCLUSION

In our experience, as in other's, pulmonary infection risk is important in lung transplantation. Bacterial infections were mainly an aggravating factor of secondary pulmonary dysfunction or OB, and were not the primary cause of death. CMV infections have been very severe and lead us, despite the scarcity of donors, to avoid positive donors in negative recipients, this leads to disastrous mid-term results in our experience, despite prophylaxis.

New directions in perioperative management for pediatric solid organ transplantation

Advances in pediatric solid organ transplantation have furthered the understanding of end-organ failures and refined the strategies for perioperative management of these otherwise lethal diseases. As the donor pool expands, the number of transplantations increases and long-term survival continues to improve, more complete knowledge of the immunologic and pathologic processes will be gained. A thorough understanding of the principles of transplantation medicine remains essential for physicians to provide optimal perioperative care of pediatric organ transplant patients.

Pediatric lung transplantation

Pediatric lung transplantation is becoming more common, and with increasing experience there is increasing success. The most common indications for considering lung transplantation are cystic fibrosis, pulmonary vascular disease (usually due to congenital heart disease), and fibrotic lung disease. The contraindications and complications are similar to adult transplant patients, although post-transplant lymphoproliferative disease and airway complications may occur more frequently. The patients with cystic fibrosis face additional obstacles to the success of transplantation: airway colonization with Gram-negative organisms, pancreatic insufficiency, glucose intolerance, and osteoporosis. The survival for children is comparable to adults, reaching about 65% at 1 year, and 69% at 2 years.

Pathology of lung allografts in children and young adults

Heart-lung and lung transplantation have become acceptable therapeutic modalities for end-stage lung and heart conditions in children and young adults, but the posttransplantation pulmonary pathology in this age-group is poorly characterized. We present our experience with the pathology of lung transplantation in a cohort of 11 patients with a median age of 12.5 years, and median posttransplantation follow-up of 8.3 months. The findings are based on histological examination of 98 specimens, including five autopsy specimens from patients 20 years of age or younger. Our experience, combined with the data in other pediatric series, suggest that there is not a significant difference in the prevalence or severity of acute rejection or bronchiolitis obliterans (BO) between adult and pediatric lung transplant recipients. Lymphocytic bronchitis/bronchiolitis showed a more prominent association with BO in our series than previously reported in adult studies. Chronic vascular rejection in the pediatric lung transplant recipients can occur earlier than reported in adults and is associated with a grave prognosis. Overwhelming infection was a major cause of death in our experience. In particular, our data combined with the previous reports indicate that adenoviral pneumonia is a relatively common pathogen in the pediatric population and is a major cause of mortality in this age-group.

Lung transplantation for treatment of infants with surfactant protein B deficiency

OBJECTIVE

To evaluate lung transplantation for treatment of surfactant protein B (SP-B) deficiency.

STUDY DESIGN

We compared surfactant composition and function from pretransplantation and posttransplantation samples of bronchoalveolar lavage fluid, somatic and lung growth, neurodevelopmental progress, pulmonary function, and pulmonary immunohistology in 3 infants with SP-B deficiency who underwent bilateral lung transplantation at 2 months of age and 3 infants who underwent lung transplantation for other reasons.

RESULTS

Two years after transplantation, the 2 surviving infants with SP-B deficiency exhibited comparable somatic growth and cognitive development to the comparison infants. All infants had delays in gross motor development that improved with time. Both groups have exhibited normal gas exchange, lung growth, and pulmonary function. The SP-B-deficient infants have also exhibited normal SP-B expression and pulmonary surfactant function after lung transplantation. In two SP-B-deficient infants antibody to SP-B developed. No pathologic consequences of this antibody were identified.

CONCLUSIONS

Apart from the development of anti-SP-B antibody, the outcomes for SP-B-deficient infants after lung transplantation are similar to those of infants who undergo lung transplantation for other reasons. Lung transplantation offers a successful interim therapy until gene replacement for this disease is available.

Airway function tests and vocal cord paralysis in lung transplant recipients

Maximum expiratory and inspiratory flow-volume (MEFV, MIFV) curves, specific airway conductance (sGaw), and flexible fiberoptic laryngoscopy were examined in 8 pediatric lung transplant recipients with vocal cord paralysis (VCP). Six were heart-lung (H-L) and 2 double-lung (D-L) recipients, 7 had left VCP, and 1 had right VCP. Based on the pulmonary function tests (PFT), 2 subgroups could be distinguished in the 8 recipients with VCP. Group A (5/8 recipients; mean age, 13 +/- 3.4 years; mean height, 144.3 +/- 12.3 cm) had significantly reduced specific airway conductance (sGaw; < 2 SD from predicted) and normal MEF25, MEF50, peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV1), and %FEV1/forced vital capacity (FVC); this pattern suggested variable extrathoracic airway obstruction. PIF was normal in 4/5 and reduced in 1/5 of these recipients. Group B (3/8 recipients with VCP; mean age, 17 +/- 2.4 years; mean height, 156.3 +/- 12.0 cm) had significantly reduced sGaw, MEF25, MEF50, PEF, FEV1, and %FEV1/FVC, implying primarily small airway obstruction. These recipients had bronchiolitis obliterans. The results suggest that a pattern of reduced sGaw and normal MEFs, PEF, FEV1, and PIF should raise the possibility of VCP in patients after lung transplantation. sGaw is more sensitive than PIF and PEF in identifying airway obstruction due to VCP, and should be routinely included in the follow-up evaluation of lung transplant recipients.

Subdural empyema due to Burkholderia cepacia: an unusual complication after lung transplantation for cystic fibrosis

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Effects of nitric oxide on hyperinflation-induced pulmonary hypertension in the isolated-perfused lung

OBJECTIVE

To determine if nitric oxide decreases pulmonary vascular resistance in hyperinflation-induced pulmonary hypertension.

DESIGN

Isolated-perfused lamb lung model.

SETTING

Experimental animal laboratory in a university setting.

SUBJECTS

Ten isolated-perfused lamb lungs harvested from subjects with a mean age of 29 days.

INTERVENTIONS

After induction of anesthesia, endotracheal intubation, and mechanical ventilation, lungs were perfused via an extracorporeal circuit. Ventilatory pressures were set to provide tidal volumes of 10 mL/kg and ventilatory rates were adjusted to maintain a Paco2 of 40 +/- 5 torr (3.5 +/- 0.7 kPa). The perfusion system consisted of a blood reservoir, a membrane oxygenator, and a nonocclusive roller pump. Blood flow was increased progressively to 50 mL/kg/min, maintaining a pulmonary arterial pressure of < 25 mm Hg and a left atrial pressure between 2 and 5 mm Hg. End-expiratory lung volume was measured using a nitrogen washout method. Baseline data were collected after a 1-hr stabilization period. Lung volume was increased to achieve 25% (moderate hyperinflation) and 50% (severe hyperinflation) increments in pulmonary vascular resistance. Nitric oxide (80 parts per million) was administered to the preparation after each increment in lung volume.

MEASUREMENTS AND MAIN RESULTS

Mean pulmonary arterial pressure, mean left atrial pressure, pulmonary vascular resistance, and static lung compliance were measured at baseline and after moderate and severe hyperinflation, both before and after nitric oxide administration. Significant decreases in pulmonary vascular resistance were found when the preparation was ventilated with nitric oxide at baseline (43% decrease) and during hyperinflation induced pulmonary hypertension at both moderate (31% decrease) and severe (23% decrease) levels of hyperinflation.

CONCLUSIONS

Inhaled nitric oxide significantly reduces pulmonary vascular resistance, even when pulmonary hypertension is induced by airway hyperinflation and supraphysiologic lung volumes. These data suggest that the use of nitric oxide following lung transplantation may allow for effective management of pulmonary hypertension in patients who receive allografts from undersized donors. Further clinical experience will be crucial in precisely defining the range of donor-recipient size mismatch that can be adequately managed and the time course over which nitric oxide can be administered safely and effectively to these patients.

Clinical denouement and mutation analysis of patients with cystic fibrosis undergoing liver transplantation for biliary cirrhosis

OBJECTIVE

To describe the clinical characteristics of patients with cystic fibrosis considered for liver transplantation and the clinical outcome after transplantation.

METHODS

Patient charts were reviewed. Mutation analysis was performed on blood or liver tissue samples with a panel of 17 mutations.

RESULTS

Eight patients (five girls) with cystic fibrosis have undergone orthotopic liver transplantation for biliary cirrhosis. Mean age at transplantation was 12.0 years +/- 7.7 years (range, 9 months to 23 years). Preoperatively, seven patients had mild to moderate pulmonary dysfunction and one moderate to severe pulmonary dysfunction. All patients required pancreatic enzyme replacement, and four patients required insulin for diabetes mellitus. The 1-year survival rate was 75%, with no deaths related to septic events. Mean time of follow-up the six operative survivors was 4.1 years +/- 1.9 years. Pulmonary function testing, in those serially tested, showed that forced expiratory volume in 1 second was maintained or improved and that forced vital capacity improved after transplantation. Mutation analysis showed the following genotypes: four patients, delta F508/delta F508; one patient, delta F508/N1303K; and three patients, delta F508/unknown.

CONCLUSIONS

Despite the high risk of transplantation, these encouraging results indicate that liver transplantation should be considered for patients with cystic fibrosis and complications of end-stage liver disease. We could not demonstrate an unusual pattern of CF gene mutations in these patients with severe liver disease. It appeared that immunosuppressive agents did not have a deleterious effect on pulmonary function.

Nutrition in the pediatric double lung transplant patient with cystic fibrosis

Cystic fibrosis (CF) is the most common lethal genetic disease in the white population. The pulmonary infections and pancreatic insufficiency make CF a medically challenging disease. Although the importance of nutrition in the CF patient is known, approximately 50% of CF patients are in less than the 10th percentile for weight and height as reported by the 1991 CF Foundation Registry of 114 CF Centers in the United States. This paper addresses the nutritional status of 10 pediatric CF patients who underwent double lung transplant at Children's Hospital of Pittsburgh between August 1991 and May 1993. Patients who survived beyond 1 year gained a significant amount of weight sooner after transplant than those who survived less than 1 year. Gastrostomy tube feedings were more effective than oral intake for weight gain after transplant. CF patients with pancreatic insufficiency have more difficulty with adjustment of doses of immunosuppressive agents for reasons that are not clearly understood.

Transmissibility of Pseudomonas cepacia infection in clinic patients and lung-transplant recipients with cystic fibrosis

BACKGROUND

In patients with cystic fibrosis, infection with Pseudomonas cepacia is associated with poor outcomes. However, the extent of person-to-person transmission and the source of P. cepacia infection after lung transplantation are not well defined. Using DNA-based typing systems, we sought to determine the genetic relatedness of P. cepacia infection at one cystic fibrosis center.

METHODS

We analyzed 65 P. cepacia isolates gathered over a period of eight years at a single cystic fibrosis center from 17 clinic patients and from 5 patients who underwent double-lung transplantation. The isolates were analyzed by ribotyping and chromosomal fingerprinting based on pulsed-field gel electrophoresis.

RESULTS

Analyses of serial isolates revealed that each clinic patient and transplant recipient harbored a different P. cepacia clone that was persistent. In the transplant recipients, the preoperative and postoperative isolates were identical. In the two patients with disseminated infection after lung transplantation, isolates from multiple sites were identical and indicated clonal expansion of the previous respiratory P. cepacia strain. Pulsed-field gel electrophoresis proved both more discriminative and more practical than ribotyping as a means of defining the genetic relatedness of the P. cepacia isolates.

CONCLUSIONS

Our serial analyses in patients with cystic fibrosis at one center found distinct strains of P. cepacia persistently infecting each patient and no evidence of person-to-person transmission of this organism. P. cepacia infection after lung transplantation was due to the persistence of the strain present before transplantation.