Changes in Thoracic Cavity Volume After Bilateral Lung Transplantation

Characterization of Baseline Lung Allograft Dysfunction in Single Lung Transplant Recipients

BACKGROUND

Baseline lung allograft dysfunction (BLAD) is characterized by the failure to achieve normal baseline lung function after double lung transplantation (DLTX) and is associated with a high risk of mortality. In single lung transplant (SLTX) recipients, however, cutoff values and associated factors have not been explored. Here, we aimed to define BLAD in SLTX recipients, investigate its impact on allograft survival, and identify potential risk factors for BLAD in SLTX recipients.

METHODS

We performed a retrospective, single-center analysis of the LTX cohort of LMU Munich between 2010 and 2018. In accordance with DLTX cutoffs, BLAD in SLTX recipients was defined as failure to achieve percentage of forced expiratory volume in 1 s and percentage of forced vital capacity of >60% on 2 consecutive tests >3 wk apart. Survival analysis and regression analysis for potential predictors of BLAD were performed.

RESULTS

In a cohort of 141 SLTX recipients, 43% of patients met BLAD criteria. SLTX recipients with BLAD demonstrated impaired survival. Native lung hyperinflation was associated with BLAD in obstructive disease, whereas donor/recipient lung size mismatch was associated with BLAD in both obstructive and restrictive underlying diseases. Pulmonary function testing at 3 mo after lung transplantation predicted normal baseline lung function in SLTX recipients with obstructive lung disease.

CONCLUSIONS

BLAD in SLTX recipients is as relevant as in DLTX recipients and should generally be considered in the follow-up of LTX recipients. Risk factors for BLAD differed between underlying obstructive and restrictive lung disease. A better understanding of associated factors may help in the development of preventive strategies.

Applied physiological principles in the management of a lung allograft to thoracic cavity size mismatch in severe emphysema

In this review, we discuss physiological principles that guided the management of a lung transplant for emphysema related to alpha-1-antitrypsin deficiency, where a lung allograft to thoracic cavity size mismatch occurred (donor-to-recipient predicted total lung capacity [pTLC] ratio was 0.89, donor pTLC-to-recipient actual-TLC ratio 0.62). In emphysema, the loss of lung elastic recoil and airway obstruction leads to air trapping and lung hyperinflation. Remodeling of the thoracic cavity ("barrel chest") develops, which has implications for donor-to-recipient sizing and postoperative management of lung transplantation. We discuss the physiology of a relatively undersized allograft and the impact on chest tube, mechanical ventilation, and respiratory system mechanics management. This case also illustrates how chronic adaptations of the ventilatory pattern to advanced lung diseases are reversible and the chest cavity size can remodel back to normal after lung transplantation.

Shah P, Mathew J, Kong H, Charya A, Luikart H, Aryal S, Nathan SD, Orens JB, Khush KK, Kyoo Jang M, Agbor-Enoh S. Baseline Lung Allograft Dysfunction After Bilateral Lung Transplantation Is Associated With an Increased Risk of Death: Results From a Multicenter Cohort Study

Background

A prior single-center, retrospective cohort study identified baseline lung allograft dysfunction (BLAD) as a risk factor for death in bilateral lung transplant recipients. In this multicenter prospective cohort study, we test the association of BLAD with death in bilateral lung transplant recipients, identify clinical risk factors for BLAD, and assess its association with allograft injury on the molecular level.

Methods

This multicenter, prospective cohort study included 173 bilateral lung transplant recipients that underwent serial pulmonary function testing and plasma collection for donor-derived cell-free DNA at prespecified time points. BLAD was defined as failure to achieve ≥80% predicted for both forced expiratory volume in 1 s and forced vital capacity after lung transplant, on 2 consecutive measurements at least 3 mo apart.

Results

BLAD was associated with increased risk of death (hazard ratio, 1.97; 95% confidence interval [CI], 1.05-3.69; P = 0.03) but not chronic lung allograft dysfunction alone (hazard ratio, 1.60; 95% CI, 0.87-2.95; P = 0.13). Recipient obesity (odds ratio, 1.69; 95% CI, 1.15-2.80; P = 0.04) and donor age (odds ratio, 1.03; 95% CI, 1.02-1.05; P = 0.004) increased the risk of developing BLAD. Patients with BLAD did not demonstrate higher log10(donor-derived cell-free DNA) levels compared with no BLAD (slope [SE]: -0.0095 [0.0007] versus -0.0109 [0.0007]; P = 0.15).

Conclusions

BLAD is associated with an increased risk of death following lung transplantation, representing an important posttransplant outcome with valuable prognostic significance; however, early allograft specific injury on the molecular level does not increase the risk of BLAD, supporting further mechanistic insight into disease pathophysiology.

Lung Donor Selection and Management: An Updated Review

The shortage of donor lungs for transplantation is a major challenge, resulting in longer waitlist times for patients with a higher risk of waitlist mortality. It is crucial to continue promoting awareness about organ donation through legislation, public campaigns, and health care provider education. Only a small number of cadaveric donors meet the ideal criteria for lung donation, leaving many lungs unused. Donor lung utilization can be improved by carefully considering the extended-criteria donors, actively participating in donor management, and by utilizing the modalities to assess and manage the marginal lungs after retrieval from the donor. The purpose of this article is to provide an up-to-date review of donor selection, assessment of donor lungs, and donor lung management to enhance organ recovery rates for lung transplantation.

Donor Selection, Management, and Procurement for Lung Transplantation

Lung transplantation is a life-saving procedure in patients with end-stage lung disease. However, it inherently depends on the availability of donor organs. The selection of suitable lungs for transplantation, management of donors to minimize further injury and improve organ function, and safe procurement remain critical for successful transplantation. In this review, we provide an update on the current understanding of donor selection, management, and lung procurement.