Extended donor criteria for lung transplantation: insights from a narrative review

Introduction

The Lung Allocation Score (LAS) was implemented in 2005 to give priority to the patients with the least time to live and those who are most likely to survive the operation, thereby minimizing the number of futile transplants and reducing waitlist mortality (1,2). LAS implementation has decreased waitlist deaths by ~40% (3), and advancements in surgical techniques, post-operative care, and immunosuppression therapy have led to improved survival outcomes following lung transplantation (1). However, an increasing number of patients on the waitlist require hospital admission for mechanical ventilation or extracorporeal membrane oxygenation (ECMO) support prior to transplant (4), and approximately 15% of patients die and another 15% are removed from the waitlist because of worsening health status (5).

Donor lung use for transplantation has been limited to approximately 20% of existing donors, which is the lowest reported utilization for solid organ transplants (6), and can likely be attributed to over-adherence to standard donor criteria. These criteria were recommended by Dr. Joel Cooper’s group at Washington University in St. Louis and endorsed by the International Society of Heart and Lung Transplantation (ISHLT) and include: age less than 55 years old, ratio of the pressure of arterial oxygen (PaO₂) to the fraction of inspired oxygen (FiO₂) (P:F) greater than 300 mmHg, less than 20 pack-years of smoking history, non-diabetic, no infiltrate noted on chest roentgenogram (CXR), and sterile bronchoalveolar lavage (BAL) cultures (7). Of note, these criteria were described over 30 years ago, and in the interim, perioperative care, surgical techniques, and immunosuppression have advanced significantly.

Approximately 10% of organ donors meet criteria as standard criteria donors (SCDs) at the time of consent for organ donation. The implementation of donor management protocols and standardization of acceptance of non-standard or extended criteria donor (ECD) lungs should yield enough donor lungs to decrease both waitlist time and mortality of recipients. From 2020 to 2022, only 10 of 44 large organ procurement organizations (OPOs) had a lung allocation rate over 25%. An average rate of lung allocation of 25% at the other large OPOs would increase the number of lung transplants enough to close the current disparity between available donor lungs and waitlist patients (8,9).

Clearly, utilization of ECD lungs must be part of the strategy to help end-stage lung disease patients. We will review each of the standard criteria, their respective importance for satisfactory outcomes, and compare outcomes between ECD and SCD transplants. We will also discuss additional extended criteria: donors positive for hepatitis C virus (HCV), donation after circulatory death (DCD), and ABO incompatibility. In addition, we will discuss real-world measures to reduce waitlist mortality by broadening donor acceptance criteria. We present this article in accordance with the Narrative Review reporting checklist (available at https://ccts.amegroups.com/article/view/10.21037/ccts-25-11/rc).

Methods

We utilized PubMed and Google Scholar to conduct a search for articles in the months of October 2024 and May 2025. The articles ranged in date of publication from January 1999 to May 2025. The search included studies published in English, focusing on systematic reviews, randomized controlled trials, consensus statements, and retrospective cohort studies. Search terms included “extended criteria donor (ECD)”, “lung transplant”, “hepatitis C”, “donation after circulatory death”, and “transplant guidelines”, combined using Boolean operators (AND, OR). Please see Table S1 for an example of the PubMed search. Two authors (J.J. and B.L.) independently screened titles and abstracts. Disagreements were resolved through discussion, and the final selections were made by consensus between all three authors. Table 1 provides an example of the search strategy employed, detailing the databases searched, search terms used, inclusion and exclusion criteria, timeframe, and selection process.

Extended criteria

Age over 55 years

Historically, donor age over 55 years has been viewed with caution due to concerns regarding increased graft dysfunction and recipient mortality. A 2007 study compared a cohort of patients that received lungs from donors aged 60 to 77 years with another cohort that received lungs from donors aged 9 to 59 years. They found that bronchiolitis obliterans syndrome (BOS) was the predominant cause of death in recipients of older donors that survived more than 90 days after surgery (10). The study showed worse overall 10-year survival for recipients of older donors but no statistically significant difference (16% for older donors vs. 39% in the younger donor group, P=0.07) (11). In 2013, a United Network for Organ Sharing (UNOS)-based analysis of over 10,000 adult lung transplant recipients reported that the use of donors over 65 years was associated with increased mortality at both 1 year [odds ratio (OR), 2.8] and 3 years (OR, 2.4) post-transplant (P<0.02) (12). These findings initially led many centers to limit donor selection to those under 65 years of age. However, evolving clinical experience has challenged these earlier concerns, suggesting that lungs from older donors, particularly those over 65 or even 70 years old, can provide acceptable outcomes when carefully matched to appropriate recipients. A study of 230 lung transplants comparing acceptance from donors over 60 years old to those under 60 years old found no difference in postoperative mortality, graft dysfunction at 3 years, or 3-year survival (13). Another analysis of 648 patients with interstitial lung disease who underwent single or double lung transplantation demonstrated no difference in survival outcomes over 5 years between transplants from donors over and under 65 years in univariable and multivariable analyses (14). Researchers from Alfred Hospital, a high-volume transplant center in Melbourne, Australia, found in a univariate analysis that donor age over 65 years old had no impact on graft survival. When they combined their cohort of 1,101 patients with the ISHLT database of 32,200, they found that univariate analysis demonstrated a negative impact on graft survival if donors were over 65 years old, but this did not hold in multivariate analysis when adjusted for transplant center experience and recipient characteristics (15). Two other studies (16,17) assessed transplant outcomes for recipients of lungs from donors over 70 years old. One was a retrospective analysis of 1,600 transplants, 98 of which involved donors over 70 years old, and a multivariable regression analysis demonstrated no difference in survival or chronic allograft dysfunction (16). Similarly, a propensity-matched analysis of 647 transplant patients (69 received lungs from donors over 70 years old) demonstrated no difference in short- or long-term outcomes, including length of ventilatory support, intensive care unit (ICU) stay, primary graft dysfunction (PGD), or 5-year survival (17). In light of this evolving evidence base, donor age alone should not serve as an absolute exclusion criterion. Instead, age should be considered within a broader context that includes donor pulmonary function, comorbidities, ischemic time, and recipient risk profile. A more nuanced approach may allow transplant programs to expand the donor pool safely without compromising recipient outcomes.

P:F less than 300 mmHg

Standard lung donor acceptance criteria mandate a P:F of greater than 300 mmHg. This strict ratio may be overly restrictive, particularly when used to reject lungs prior to direct visualization in the operating room. In many cases, a low P:F may be driven primarily by easily reversible causes, such as atelectasis, that are common in donors. To further examine this, a cohort of 93 lung transplant patients was followed to assess the importance of P:F being greater than 300 mmHg. Twelve of the donor lungs had P:F less than 300 mmHg. After transplantation, 77 of the 81 patients in the P:F over 300 group and 11 of the 12 in the P:F less than 300 group had PGD grade 0. No significant difference was found in peak lung function tests at 6 or 12 months, PGD grade, time to extubation, or 1-year mortality. They deem the P:F greater than 300 benchmark as unnecessarily conservative as 36% of the lungs that were successfully transplanted at their institution would have been rejected (11,18).

An additional review of UNOS data from 2000 to 2009 involving 12,045 transplants failed to demonstrate an association between P:F and decreased graft survival or overall survival after single or double lung transplant, even with P:F less than 200 in 1,830 of the patients (19,20). This may be due to lower PaO₂ on initial assessment that improves after recruitment maneuvers, which are not consistently captured in the database (20). As most donor lungs are either declined or not allocated due to P:F, relaxing this threshold or delaying the decision on acceptance of the organs until intraoperative visual assessment of the lungs after opening the chest following recruitment maneuvers may increase donor acceptance (21).

An Australian protocol demonstrated that using donor lungs with initial P:F below 300, if improved above 300 with recruitment maneuvers, was not associated with decreased survival or PGD at 30 days, 1, 2, or 3 years. This group’s protocol of ventilator management, recruitment, fluid management, and bronchoscopy was able to increase P:F to over 300 mmHg in 20 of 59 potential donor lungs initially deemed marginal, and increased procurement rates from 33% to 51% (9,20,22). The San Antonio Lung Transplant (SALT) protocol used pressure control ventilation with an inspiratory pressure of 25 cmH₂O and positive end-expiratory pressure (PEEP) of 15 cmH₂O for 2 hours to aggressively recruit donor lungs. They studied 98 lung donors and the P:F in 31% was able to be improved to over 300 mmHg. Fifty-three of them were initially deemed poor donors, but ended up providing over half of the 121 lung transplants in their study. They found no significant difference in 30-day or 1-year survival rates between recipients of lungs from ideal donors vs. the donor lungs that became suitable after undergoing the SALT protocol (9,23).

A European multicenter randomized trial examined the use of a similar protective ventilator strategy and doubled lung recovery rates (54% vs. 27%, P<0.005) (9,24). A consensus statement recommended the following ventilator strategy for initial management, recruitment, and maintenance of donor lungs: tidal volume of 8 mL/kg (ideal body weight), PEEP 8–10 cmH₂O for maintenance, PEEP up to 15 cmH₂O for recruitment based on oxygenation, plateau pressure less than 30 cmH₂O, inspiratory to expiratory ratio (I:E) 1:1 to 1:1.5, and respiratory rates between 10 and 18 as needed to keep partial pressure of carbon dioxide (PCO₂) between 35 and 40 mmHg (9,25).

As noted in one analysis, P:F may be inaccurate in assessing intrapulmonary shunt in donation after brain death (DBD) due to reduced oxygen consumption and elevated oxygen delivery, as well as in ex vivo lung perfusion (EVLP) due to high venous oxygen saturation and reduced perfusate oxygen-carrying capacity (26). Therefore, this criterion too may need to be adjusted or abandoned as technology advances to prevent unnecessary rejection of donor lungs.

Greater than 20 smoking pack-years

Until recently, most evidence indicated that of all the extended donor lung criteria, donor smoking history impacts recipient morbidity and mortality, but studies have been hampered by lack of granularity and consistency in terms of intensity of smoking, current vs. past smoking, etc. An analysis using UNOS data from 2005 to 2011 found that in their population of 5,900 double-lung transplants, the 766 recipients of lungs from donors with over 20 smoking pack-years had a median length of stay (LOS) only 1 day longer and no difference was noted in BOS incidence, postoperative forced expiratory volume in 1 second (FEV1), or median survival. Greater than 20 smoking pack-years was also not found to have an association with recipient death on multivariate analysis (27).

In 2016, the ISHLT issued a consensus statement clearly identifying donor smoking as a risk factor for PGD (11,28) based on a study by Diamond et al. in which their multivariable model showed that donor smoking was an independent risk factor for PGD [OR, 1.8; 95% confidence interval (CI): 1.2–2.6; P=0.002]. In this study, PGD was significantly associated with 90-day (relative risk, 4.8; absolute risk increase, 18%; P<0.001) and 1-year (relative risk, 3; absolute risk increase, 23%; P<0.001) mortality (29). Excluding these donors could excessively limit the donor pool due to the high prevalence of smoking in the donor population (21). Fortunately, emerging data suggest that donor smoking history may not be as detrimental as previously thought.

An analysis of 1,366 lung transplants at Cleveland Clinic in which 49% received an organ from a smoker and 25% received an organ from a smoker of greater than 20 pack-years showed slightly worse FEV1 (70% in smoking donor recipients vs. 74% in nonsmoking donor recipients) and slightly worse risk-adjusted recipient survival with increasing donor smoking pack-years. However, there were no significant differences in non-risk adjusted 5-year survival or PGD (30).

A multicenter prospective cohort study of lung transplant recipients enrolled in the Lung Transplant Outcomes Group separated donors into active, passive, and non-smokers based on urinary smoking biomarkers. They found that donor smoking was associated with a modest increase in PGD risk but no significant increase in mortality up to 3 years post-transplant. The authors acknowledge that there was a limited population of smokers of greater than 20 pack-years in this study due to current practices as stated above (31). As mentioned, it is difficult to accurately quantify what level of smoking affords the lowest risk to transplant recipients due to lack of granularity in available data. However, these results are encouraging as they show that otherwise appropriate lungs should not be rejected. Though outcomes have been reported to be slightly worse in recipients of lungs from smoking donors, the clinical significance may be minimal and must be balanced against the fact that even if there is an increased mortality risk of patients receiving smoking donor lungs, this is likely a lower mortality risk than that of the patients on the transplant waiting list (20).

Diabetes

Diabetes can lead to micro- and macrovascular changes resulting in fibrosis of the pulmonary parenchyma and interstitial disease secondary to continuous inflammation in some patients (11,32). One retrospective study using the UNOS database found that a diabetic donor was an independent predictor of mortality at 5 years post-transplant but had no association with 5-year mortality if the recipient was also diabetic (33). In a separate analysis of the UNOS database, researchers found that patients for whom a single lung was accepted from a diabetic donor, there was an increased risk of death, but no such association was found in double lung transplant. Subanalysis revealed that transplantation from donors who had diabetes for less than 5 years did not have any significant difference in outcomes when compared to non-diabetic donors. The authors acknowledge that they lacked granularity on donor glycemic control and end-organ disease secondary to diabetes (34). Based on this data, it is not unreasonable to accept lungs from a diabetic donor.

CXR with infiltrates

A retrospective study found that 37% of potential donor CXRs showed initial densities, with bilateral infiltrates in 25% of cases. During the mean evaluation period of 69.7 hours, 38% of right lungs and 28% of left lungs improved radiographically and 51% of lungs with initial infiltrate completely resolved (35). Improvement in infiltrates was not associated with increased transplantation rates, indicating possibly unnecessary rejection (20). All patients with findings of infiltrates who were transplanted were alive at 1-year follow-up (35). Similar to the initial P:F in potential donor lungs, radiographic consolidations may resolve with recruitment maneuvers or intraoperative findings may not be consistent with imaging. A recent study suggests that radiographic imaging should not be a sole criterion for donor rejection without the context of bronchoscopy, arterial blood gas, etc. (21).

Positive BAL culture

A single-center retrospective study found that although 12% of recipients of donor lungs with a positive gram stain subsequently developed pneumonia, 20% of recipients of donor lungs with a negative gram stain still developed pneumonia (P=0.26) (36). Of note, donor lungs were rejected in this study if bronchoscopy was concerning for frank aspiration (20). A prospective analysis of donor airway cultures and bronchial tissue cultures in 140 lung transplants showed less than 1.5% transmission rate of donor organ contamination based on genotyping of the donor organism and organism causing post-transplant infection (37). Another study testing empiric prophylactic antibiotic usage found that positive cultures did not affect 30-day mortality, hospital LOS, or ICU LOS, even if the empiric antibiotic was “inappropriate” based on culture growth (38). As long as standard antibiotics covering Pseudomonas and Staphylococcus aureus are used prophylactically, there is negligible risk of transmitting a donor infection (20).

HCV-positive (HCV+) donors

Thanks to effective treatment with oral direct-acting antiviral agents (DAAs) more lungs from HCV⁺ donors are being utilized (39). Active HCV infection results in a nucleic acid test-positive (NAT⁺). Those who have had recent HCV exposure, or had an active infection that was treated or resolved spontaneously may be NAT-negative (NAT⁻) but antibody-positive (AB⁺) (40). The risk of transmission from an NAT⁻/AB⁺ donor is very low, but NAT⁺ donors have a high transmission risk so patients who receive their organs require DAAs. By following this protocol, similar short-term survival and graft function can be achieved compared to HCV-negative (HCV⁻) donation (41). A prospective single-arm trial comparing transplantation of HCV⁺vs. HCV⁻ donor lungs in HCV⁻ recipients found that with 8-week post-implant DAA treatment, there were equivalent outcomes at 1 year (42).

An ISHLT consensus statement in 2020 proposed guidelines outlining prophylactic and preemptive strategies in the use of HCV⁺ donor lungs. The prophylactic strategy involves DAAs being started preoperatively or within hours of the transplant, while the preemptive strategy relies on transmission verification with polymerase chain reaction (PCR) that is performed weekly until 1 month, then again at 3 months. Treatment is continued with quantitative RNA testing every 4 weeks and following the end of treatment until sustained virologic response 12 weeks after the end of treatment. They acknowledge a paucity of evidence regarding long-term outcomes following use of HCV⁺ donors in the DAA era and as such, communication of risk during informed consent is imperative (40).

DCD

The use of DCD lungs will be discussed in more detail later in this series, but with the increasing use of EVLP technology may significantly improve access to donor lungs. From 2005 to 2020, DCD donors only accounted for 2.6% of lung transplants in the United States (43). A population-based cohort study estimated that if all optimal DCD lungs were identified and utilized, the donor lung supply could increase by up to 22.7%. If optimal and suboptimal DCD lungs were utilized the supply increase could be up to 50% (44). A large study examining ISHLT Registry data compared 1,090 DCD lung transplants to DBD transplants and found no difference in 5-year survival rates and donor type was not found to impact survival on subsequent multivariable analysis (45).

ECD in DCD transplants was examined in a study that included 827 patients who were classified as ECD if there was any variance from the standard criteria; 52.7% of the recipients received ECD lungs. No significant differences were found in 30-day, 90-day, or 1-year mortality. There was also no difference in LOS, requirement of ventilatory support for greater than 48 hours, reintubation, incidence of PGD grade 3, acute rejection, or dialysis. There was also no significant difference in 5-year overall survival. This study did not find that any of the standard criteria impacted 5-year survival in DCD transplants (46).

ABO incompatibility

There are several techniques that have been used in other solid organ transplants for ABO desensitization, which may offer another solution to increase donor lung availability. These include removal of circulating ABO antibodies with plasmapheresis or immunoadsorption, immunomodulation by administration of high-dose polyclonal intravenous immunoglobulin before transplant, and B-cell depletion using rituximab (11,47,48). However, intentional ABO-incompatible lung transplantation remains extremely rare and should only be considered in critically ill patients at imminent risk of death without transplantation who do not have any other reasonable option for transplantation.

SCD vs. ECD

A retrospective review of 24,888 patients in the UNOS database from May 2005 to December 2018 was conducted to assess utilization of ECD and to compare outcomes with SCD transplants. Twenty percent utilized SCD, 80% had one or more extended criteria, and 42% had two or more extended criteria. They found that annual lung transplant volume increased from 1,352 in 2005 to 2,495 in 2018, usage of SCD went from 34% to 14%, and usage of donors with 2 or 3 extended criteria increased from 25% to 44%. Overall, 1-year survival improved from 87% to 90% for SCD and 81% to 89% for ECD. There was no significant difference in 30-day mortality, 90-day mortality, or 1-year survival between SCD and ECD recipients. They found that the variables associated with worse 1-year survival were smoking pack-years greater than 20, 55 years of age or older, and diabetic patients (49).

A retrospective analysis was performed by a group in South Korea to compare SCD and ECD transplants. This included a population of 246 patients who underwent double-lung transplantation—72.8% with SCD and 27.2% with ECD. In their logistic regression model and multivariate analysis, ECD was significantly associated with risk of failure of ECMO weaning in the operating room, but there was no association with risk of PGD grade 3 at 72 hours after transplantation. There were no significant differences between the two groups in early postoperative outcomes, including the length of mechanical ventilation, LOS, or overall survival at 3 years (50).

Impacting waitlist mortality

A retrospective analysis of UNOS data on all waitlisted candidates for lung transplantation from May 2007 to March 2017 found that transplant centers vary widely in acceptance rate, from 9% to 67%. They found that for every 10% increase in adjusted center acceptance rate, the risk of waitlist mortality decreased by 36%. Notably, their data showed that when a first-ranked offer (when they become the highest-priority candidate on the waitlist) is declined for the candidate by a center, 38% never receive a subsequent first-ranked offer, and many never proceed to a transplant. Their data further demonstrated that there was no difference in outcomes between candidates that accepted a first-ranked offer vs. those that accepted allografts declined by higher-priority candidates. This suggests that broader acceptance of organs that do not meet standard criteria will reduce waitlist mortality by redirecting organs to the highest-priority candidates. The Scientific Registry of Transplant Recipients (SRTR) is making offer-acceptance statistics available to lung transplant centers in an effort to facilitate targeted intervention to standardize acceptance of ECD lungs and improve efficacy of allocation (51).

Similarly, another analysis of UNOS data examining waitlisted candidates matched to an ECD lung offer found that only 21% accepted the offer. Those who accepted the ECD offer had significantly improved cumulative mortality at 1 year (14.1% vs. 23.9%, P<0.001) and 5 years (48.4% vs. 53.8%, P<0.001), demonstrating that rejection of ECD offers obviously decreases rate of lung transplantation but also leads to worse survival (52). These trends support the ongoing reassessment of donor selection practices to safely improve access for candidates with urgent need.

One route to solving this problem is to increase OPO utilization of ECD lungs. A retrospective analysis of the UNOS data was performed and three tiers of OPOs were determined based on rates of pursuit of ECD organs and those deemed increased risk donors (increased risk for hepatitis B virus, HCV, or human immunodeficiency virus). They propose that just as SRTR is making statistics available to transplant centers, OPOs can be placed in their respective tiers with detailed data on acceptance rates. This holds the OPOs accountable while giving them actionable information to help standardize acceptance criteria, thereby increasing the use of ECD organs and decreasing waitlist mortality (53).

Limitations

This narrative review has several limitations inherent to its scope and methodology. First, much of the data presented is derived from retrospective studies, as it would be unethical to knowingly accept a “worse”-quality lung. Thus, the data is prone to selection bias and confounding variables. In addition, the studies that do not utilize single-center retrospective data often rely on large databases, such as UNOS and ISHLT, which may lack details regarding variables like smoking intensity (e.g., exact pack-years), the extent of infiltrates on imaging, specifics and/or timing of recruitment maneuvers used, P:F measurements, etc. Additionally, the majority of the studies focus on short- to medium-term outcomes, with fewer robust analyses on long-term survival and quality of life following transplantation of ECD lungs. The ethical constraints of conducting prospective randomized trials in this field results in a reliance on observational data, which limits the ability to definitively establish causation between extended donor criteria and patient outcomes. Furthermore, the findings across studies are not always consistent, likely due to differences in study designs, patient populations, and clinical protocols. Finally, while promising advances like EVLP have been highlighted as potential solutions to mitigate the risks associated with ECD lungs, the data on these technologies is still evolving, and their widespread adoption may vary depending on institutional resources and expertise. As such, the conclusions of this review must be interpreted with caution, emphasizing the need for further research, particularly prospective multicenter studies, to better define and optimize the use of ECD lungs in transplantation. However, the UNOS or ISHLT databases provide access to the data of a large population of patients that is otherwise unattainable, and the analyses discussed herein are promising for the future of lung transplants. As more ECD lungs are used, the retrospective data will become more robust, offering increased power for retrospective studies.

Conclusions

A shortage of donor lungs results in increased ICU admissions of patients on the waitlist, often requiring mechanical ventilation or ECMO, which comes with significant cost burden to the patient and the healthcare system. This shortage should not be exacerbated by over-adherence to standard criteria that have been obviated by advances in technology, immunosuppression, and perioperative care. Our review suggests that accepting organs from donors with greater than 20 smoking pack-years or diabetes may negatively impact outcomes, but as outlined in the sections above, none of the standard criteria have definitively been associated with worse outcomes. EVLP will be discussed elsewhere in this series, but is bringing about a paradigm shift, especially with portable models that can ameliorate or eliminate the effects of extended criteria, DCD pathology, and/or longer ischemic times. At a minimum, the standard criteria should not be used as an automatic cutoff tool, and transplant teams should be open to the use of ECD lungs on a case-by-case basis. Thankfully, the use of ECD lungs seems to be increasing and efforts are underway to standardize acceptance at transplant centers and OPOs. This, in addition to, and in conjunction with, the burgeoning wave of EVLP will lead us toward minimization of waitlist mortality.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editor (Haytham Elgharably) for the series “Lung Transplantation: New Frontiers” published in Current Challenges in Thoracic Surgery. The article has undergone external peer review.

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://ccts.amegroups.com/article/view/10.21037/ccts-25-11/rc

Peer Review File: Available at https://ccts.amegroups.com/article/view/10.21037/ccts-25-11/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://ccts.amegroups.com/article/view/10.21037/ccts-25-11/coif). The series “Lung Transplantation: New Frontiers” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The ethical considerations for lung transplant donor criteria emphasize beneficence, non-maleficence, and informed consent. Expanding donor criteria to include ECDs aims to increase viable transplants and reduce waitlist mortality but raises concerns about organ quality and safety. Informed consent is critical, requiring patients to be fully aware of the risks and benefits associated with ECDs, particularly regarding donor characteristics. Researchers must interpret retrospective studies cautiously, recognizing biases in donor selection and post-operative care. Ongoing refinement of donor criteria and innovative technologies, such as EVLP, are necessary, ensuring patient welfare and equitable access to transplants while advancing lung transplantation practices.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Neizer H, Singh GB, Gupta S, et al. Addressing donor-organ shortages using extended criteria in lung transplantation. Ann Cardiothorac Surg 2020;9:49-50. [Crossref] [PubMed]
2. Eberlein M, Garrity ER, Orens JB. Lung allocation in the United States. Clin Chest Med 2011;32:213-22. [Crossref] [PubMed]
3. Egan TM, Edwards LB. Effect of the lung allocation score on lung transplantation in the United States. J Heart Lung Transplant 2016;35:433-9. [Crossref] [PubMed]
4. Keeshan BC, Rossano JW, Beck N, et al. Lung transplant waitlist mortality: height as a predictor of poor outcomes. Pediatr Transplant 2015;19:294-300. [Crossref] [PubMed]
5. Valapour M, Lehr CJ, Skeans MA, et al. OPTN/SRTR 2016 Annual Data Report: Lung. Am J Transplant 2018;18:363-433. [Crossref] [PubMed]
6. Loor G, Warnecke G, Villavicencio MA, et al. Portable normothermic ex-vivo lung perfusion, ventilation, and functional assessment with the Organ Care System on donor lung use for transplantation from extended-criteria donors (EXPAND): a single-arm, pivotal trial. Lancet Respir Med 2019;7:975-84. [Crossref] [PubMed]
7. Sundaresan S, Trachiotis GD, Aoe M, et al. Donor lung procurement: assessment and operative technique. Ann Thorac Surg 1993;56:1409-13. [Crossref] [PubMed]
8. Hrsa.gov. National Data - OPTN. 2019. Available online: https://optn.transplant.hrsa.gov/data/view-data-reports/national-data/
9. Lesko MB, Angel LF. Organ Donation, the Non-Perfect Lung Donor, and Variability in Conversion to Transplant. Clin Chest Med 2023;44:69-75. [Crossref] [PubMed]
10. De Perrot M, Waddell TK, Shargall Y, et al. Impact of donors aged 60 years or more on outcome after lung transplantation: results of an 11-year single-center experience. J Thorac Cardiovasc Surg 2007;133:525-31. [Crossref] [PubMed]
11. Noda K, Furukawa M, Chan EG, et al. Expanding Donor Options for Lung Transplant: Extended Criteria, Donation After Circulatory Death, ABO Incompatibility, and Evolution of Ex Vivo Lung Perfusion. Transplantation 2023;107:1440-51. [Crossref] [PubMed]
12. Bittle GJ, Sanchez PG, Kon ZN, et al. The use of lung donors older than 55 years: a review of the United Network of Organ Sharing database. J Heart Lung Transplant 2013;32:760-8. [Crossref] [PubMed]
13. López I, Zapata R, Solé J, et al. Early and mid-term results of lung transplantation with donors 60 years and older. Interact Cardiovasc Thorac Surg 2015;20:47-53. [Crossref] [PubMed]
14. Hanna K, Calvelli H, Kashem MA, et al. Donor and Recipient Age in Interstitial Lung Disease: Types of Lung Transplant Survival Outcomes. J Surg Res 2024;293:136-43. [Crossref] [PubMed]
15. Darie AM, Levvey BJ, Shingles HV, et al. Impact of donor age ≥65 years on graft survival in large lung transplant cohorts. J Heart Lung Transplant 2025;44:770-9. [Crossref] [PubMed]
16. Saddoughi SA, Dunne B, Campo-Canaveral de la Cruz JL, et al. Extending the age criteria of lung transplant donors to 70+ years old does not significantly affect recipient survival. J Thorac Cardiovasc Surg 2024;167:861-8. [Crossref] [PubMed]
17. Vanluyten C, Vandervelde CM, Vos R, et al. Lung Transplant Outcome From Selected Older Donors (≥70 Years) Equals Younger Donors (<70 Years): A Propensity-matched Analysis. Ann Surg 2023;278:e641-9. [Crossref] [PubMed]
18. Whitford H, Kure CE, Henriksen A, et al. A donor PaO2/FiO2< 300 mm Hg does not determine graft function or survival after lung transplantation. J Heart Lung Transplant 2020;39:53-61. [Crossref] [PubMed]
19. Zafar F, Khan MS, Heinle JS, et al. Does donor arterial partial pressure of oxygen affect outcomes after lung transplantation? A review of more than 12,000 lung transplants. J Thorac Cardiovasc Surg 2012;143:919-25. [Crossref] [PubMed]
20. Chaney J, Suzuki Y, Cantu E 3rd, et al. Lung donor selection criteria. J Thorac Dis 2014;6:1032-8. [PubMed]
21. Kukreja J, Chen J, Brzezinski M. Redefining marginality: donor lung criteria. Curr Opin Organ Transplant 2020;25:280-4. [Crossref] [PubMed]
22. Gabbay E, Williams TJ, Griffiths AP, et al. Maximizing the utilization of donor organs offered for lung transplantation. Am J Respir Crit Care Med 1999;160:265-71. [Crossref] [PubMed]
23. Angel LF, Levine DJ, Restrepo MI, et al. Impact of a lung transplantation donor-management protocol on lung donation and recipient outcomes. Am J Respir Crit Care Med 2006;174:710-6. [Crossref] [PubMed]
24. Mascia L, Pasero D, Slutsky AS, et al. Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation: a randomized controlled trial. JAMA 2010;304:2620-7. [Crossref] [PubMed]
25. Copeland H, Hayanga JWA, Neyrinck A, et al. Donor heart and lung procurement: A consensus statement. J Heart Lung Transplant 2020;39:501-17. [Crossref] [PubMed]
26. Fumagalli J, Colombo SM, Scaravilli V, et al. Limitations of arterial partial pressure of oxygen to fraction of inspired oxygen ratio for the evaluation of donor lung function. Artif Organs 2022;46:2313-8. [Crossref] [PubMed]
27. Taghavi S, Jayarajan S, Komaroff E, et al. Double-lung transplantation can be safely performed using donors with heavy smoking history. Ann Thorac Surg 2013;95:1912-7; discussion 1917-8. [Crossref] [PubMed]
28. Diamond JM, Arcasoy S, Kennedy CC, et al. Report of the International Society for Heart and Lung Transplantation Working Group on Primary Lung Graft Dysfunction, part II: Epidemiology, risk factors, and outcomes-A 2016 Consensus Group statement of the International Society for Heart and Lung Transplantation. J Heart Lung Transplant 2017;36:1104-13. [Crossref] [PubMed]
29. Diamond JM, Lee JC, Kawut SM, et al. Clinical risk factors for primary graft dysfunction after lung transplantation. Am J Respir Crit Care Med 2013;187:527-34. [Crossref] [PubMed]
30. Rappaport JM, Siddiqui HU, Thuita L, et al. Effect of donor smoking and substance use on post-lung transplant outcomes. J Thorac Cardiovasc Surg 2023;166:383-393.e13. [Crossref] [PubMed]
31. Diamond JM, Cantu E, Calfee CS, et al. The Impact of Donor Smoking on Primary Graft Dysfunction and Mortality after Lung Transplantation. Am J Respir Crit Care Med 2024;209:91-100. [Crossref] [PubMed]
32. Rajasurya V, Gunasekaran K, Surani S. Interstitial lung disease and diabetes. World J Diabetes 2020;11:351-7. [Crossref] [PubMed]
33. Mardock AL, Ragalie WS, Rudasill SE, et al. Impact of Donor Diabetes on Outcomes of Lung Transplantation in the United States. J Surg Res 2019;244:146-52. [Crossref] [PubMed]
34. Ambur V, Taghavi S, Jayarajan S, et al. The impact of lungs from diabetic donors on lung transplant recipients†. Eur J Cardiothorac Surg 2017;51:285-90. [PubMed]
35. McCowin MJ, Hall TS, Babcock WD, et al. Changes in radiographic abnormalities in organ donors: associations with lung transplantation. J Heart Lung Transplant 2005;24:323-30. [Crossref] [PubMed]
36. Weill D, Dey GC, Hicks RA, et al. A positive donor gram stain does not predict outcome following lung transplantation. J Heart Lung Transplant 2002;21:555-8. [Crossref] [PubMed]
37. Mattner F, Kola A, Fischer S, et al. Impact of bacterial and fungal donor organ contamination in lung, heart-lung, heart and liver transplantation. Infection 2008;36:207-12. [Crossref] [PubMed]
38. Howell CK, Paciullo CA, Lyon GM, et al. Effect of positive perioperative donor and recipient respiratory bacterial cultures on early post-transplant outcomes in lung transplant recipients. Transpl Infect Dis 2017; [Crossref] [PubMed]
39. Saddoughi SA, Cypel M. Expanding the Lung Donor Pool: Donation After Circulatory Death, Ex-Vivo Lung Perfusion and Hepatitis C Donors. Clin Chest Med 2023;44:77-83. [Crossref] [PubMed]
40. Aslam S, Grossi P, Schlendorf KH, et al. Utilization of hepatitis C virus-infected organ donors in cardiothoracic transplantation: An ISHLT expert consensus statement. J Heart Lung Transplant 2020;39:418-32. [Crossref] [PubMed]
41. Woolley AE, Singh SK, Goldberg HJ, et al. Heart and Lung Transplants from HCV-Infected Donors to Uninfected Recipients. N Engl J Med 2019;380:1606-17. [Crossref] [PubMed]
42. Lewis TC, Lesko M, Rudym D, et al. One-year immunologic outcomes of lung transplantation utilizing hepatitis C-viremic donors. Clin Transplant 2022;36:e14749. [Crossref] [PubMed]
43. Bobba CM, Whitson BA, Henn MC, et al. Trends in Donation After Circulatory Death in Lung Transplantation in the United States: Impact Of Era. Transpl Int 2022;35:10172. [Crossref] [PubMed]
44. Halpern SD, Hasz RD, Abt PL. Incidence and distribution of transplantable organs from donors after circulatory determination of death in U.S. intensive care units. Ann Am Thorac Soc 2013;10:73-80. [Crossref] [PubMed]
45. Van Raemdonck D, Keshavjee S, Levvey B, et al. Donation after circulatory death in lung transplantation-five-year follow-up from ISHLT Registry. J Heart Lung Transplant 2019;38:1235-45. [Crossref] [PubMed]
46. Zhang W, Zhang C, Liu H, et al. Extended Criteria Donor Use in Lung Transplants From Donation After Controlled Circulatory Death. Transplant Proc 2024;56:1633-8. [Crossref] [PubMed]
47. Salvadori M, Tsalouchos A. Current protocols and outcomes of ABO-incompatible kidney transplantation. World J Transplant 2020;10:191-205. [Crossref] [PubMed]
48. Skogsberg Dahlgren U, Herlenius G, Gustafsson B, et al. Excellent outcome following emergency deceased donor ABO-incompatible liver transplantation using rituximab and antigen specific immunoadsorption. Scand J Gastroenterol 2022;57:50-9. [Crossref] [PubMed]
49. Christie IG, Chan EG, Ryan JP, et al. National Trends in Extended Criteria Donor Utilization and Outcomes for Lung Transplantation. Ann Thorac Surg 2021;111:421-6. [Crossref] [PubMed]
50. Suh JW, Lee JG, Park MS, et al. Impact of extended-criteria donor lungs according to preoperative recipient status and age in lung transplantation. Korean J Transplant 2020;34:185-92. [Crossref] [PubMed]
51. Mulvihill MS, Lee HJ, Weber J, et al. Variability in donor organ offer acceptance and lung transplantation survival. J Heart Lung Transplant 2020;39:353-62. [Crossref] [PubMed]
52. Cox ML, Mulvihill MS, Choi AY, et al. Implications of declining donor offers with increased risk of disease transmission on waiting list survival in lung transplantation. J Heart Lung Transplant 2019;38:295-305. [Crossref] [PubMed]
53. Halpern SE, McConnell A, Peskoe SB, et al. A three-tier system for evaluation of organ procurement organizations’ willingness to pursue and utilize nonideal donor lungs. Am J Transplant 2021;21:1269-77. [Crossref] [PubMed]