Impact of Donor Arterial Partial Pressure of Oxygen on Outcomes After Lung Transplantation in Adult Cystic Fibrosis Recipients

Suboptimal Donors Do Not Mean Worse Results: A Single-Center Study of Extending Donor Criteria for Lung Transplant

BACKGROUND

Lung transplant remains the only viable treatment for most of the end-stage lung diseases. It is believed that extending criteria for donor lungs would increase the number of lung transplants. The aim of the study was to compare the graft function by means of oxygenation index among recipients who received the lungs from donors of extended criteria with those whose received lungs from donors who met the standard criteria.

METHODS

This retrospective study analyzed 71 donors whose lungs where transplanted into 71 first-time double lung recipients of 2 groups: patients who received transplants before and after 2018. The objective was to assess whether there is a significant difference in quality of the donor pool after applying extended criteria. The second objective was to compare results of recipients with lungs from donors of oxygenation index > 400 mm Hg with those obtained among recipients with this parameter < 400 mm Hg.

RESULTS

In the case of transplants performed in 2018 to 2019, oxygenation indices were significantly lower in donors but significantly higher in recipients on the first day than those observed in 2015 to 2017. The number of transplants increased from 9 per year to 22 per year. Irrespective of whether the donor had PaO₂/fraction of inspired oxygen above or below 400 mm Hg, recipients showed similar oxygenation index values after transplant (mean oxygenation index, 462 vs 412 mm Hg, respectively). Short-term mortality did not differ either.

CONCLUSIONS

Extended criteria of lungs suitability as a potential grafts not only increases the donor pool but also proves that suboptimal donors are not associated with producing inferior results of the recipients.

Bronchiolitis obliterans syndrome-free survival after lung transplantation: An International Society for Heart and Lung Transplantation Thoracic Transplant Registry analysis

BACKGROUND

Lung transplant (LTx) recipients have low long-term survival and a high incidence of bronchiolitis obliterans syndrome (BOS). However, few long-term, multicenter, and precise estimates of BOS-free survival (a composite outcome of death or BOS) incidence exist.

METHODS

This retrospective cohort study of primary LTx recipients (1994-2011) reported to the International Society of Heart and Lung Transplantation Thoracic Transplant Registry assessed outcomes through 2012. For the composite primary outcome of BOS-free survival, we used Kaplan-Meier survival and Cox proportional hazards regression, censoring for loss to follow-up, end of study, and re-LTx. Although standard Thoracic Transplant Registry analyses censor at the last consecutive annual complete BOS status report, our analyses allowed for partially missing BOS data.

RESULTS

Due to BOS reporting standards, 99.1% of the cohort received LTx in North America. During 79,896 person-years of follow-up, single LTx (6,599 of 15,268 [43%]) and bilateral LTx (8,699 of 15,268 [57%]) recipients had a median BOS-free survival of 3.16 years (95% confidence interval [CI], 2.99-3.30 years) and 3.58 years (95% CI, 3.53-3.72 years), respectively. Almost 90% of the single and bilateral LTx recipients developed the composite outcome within 10 years of transplantation. Standard Registry analyses "overestimated" median BOS-free survival by 0.42 years and "underestimated" the median survival after BOS by about a half-year for both single and bilateral LTx (p < 0.05).

CONCLUSIONS

Most LTx recipients die or develop BOS within 4 years, and very few remain alive and free from BOS at 10 years post-LTx. Less inclusive Thoracic Transplant Registry analytic methods tend to overestimate BOS-free survival. The Registry would benefit from improved international reporting of BOS and other chronic lung allograft dysfunction (CLAD) events.