Faculty Bibliography

Primary graft dysfunction (PGD) is a proinflammatory syndrome occurring within the first days following lung transplantation. It is initiated by ischemia-reperfusion injury and perpetuated by donor and recipient immunologic factors, resulting in alveolar damage and progressive hypoxemic respiratory failure.¹ PGD is a known risk factor for both early allograft failure and chronic lung allograft dysfunction (CLAD).² Incidence of severe PGD remains high at 10-25%, though is variable; risk factors for PGD include center experience, underlying recipient disease type, size matching, donor lung storage conditions, operative time, and post-operative management.² Strategies to prevent PGD or mitigate the long -term consequences after it develops, are sorely needed. However, lack of specificity of the current PGD definition may hamper further progress in the field, especially as it pertains to the development of robust and relevant clinical trials. We propose that future modifications of the PGD definition incorporate more objective surrogates of allograft injury and subsequent diffuse alveolar damage, which may improve our ability to accurately study disease pathogenesis and improve outcomes.

In the face of a growing mismatch between candidates awaiting transplantation and the supply of conventional donor organs, attention has shifted toward novel methods to increase the donor pool, including the use of donation after circulatory death (DCD) and the refinement of procurement techniques that safeguard graft quality. Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a new strategy, leveraging extracorporeal support to curtail warm-ischemic injury while permitting in situ functional assessment. This review covers the rationale behind the use of TA-NRP, while outlining its use during procurement and the current body of evidence gathered on it implementation in lung transplantation specifically.

BACKGROUND:Donor to recipient size matching is an essential part of lung transplantation, with significant mismatch leading to worse patient outcomes. The current practice is based on limited data along with broadly accepted themes that have not been articulated in the form of objective and definitive guidelines. The objective of the American Association for Thoracic Surgery (AATS) Clinical Practice Standards Committee (CPSC) expert panel was to develop evidence- and expert-based recommendations for optimal donor to recipient lung allograft size matching based on review of the existing literature. METHODS:The AATS CPSC assembled an expert panel of 18 lung transplant surgeons from 15 centers who developed a consensus document of recommendations. The panel was divided into subgroups covering size-matching in (1) bilateral lung transplantation, (2) single lung transplantation, (3) lobar transplantation, (4) unique situations, and (5) management of complications following severe size mismatch. Following a focused literature review, each subgroup formulated recommendation statements for each subtopic, which were reviewed and further refined using a Delphi process until consensus was achieved on each final statement by the voting group. RESULTS:The expert panel achieved consensus on 20 recommendations for current best practices in donor and recipient size matching. These recommendations include utilization of a ratio of donor-to-recipient predicted total lung capacity between 0.8 to 1.2, with special considerations based on recipient pathology, single lung or lobar transplantation, and anatomic variations such as chest wall abnormalities or significant mediastinal shift. Furthermore, oversized allografts can be reduced in size via non-anatomic or anatomic resection in select cases when required. CONCLUSIONS:Consistent practice guidelines regarding donor to recipient size matching will be helpful and important to achieve optimal outcomes in lung transplantation. The recommendations described here provide guidance for professionals involved in the care of patients with end-stage lung disease considered for transplantation.

OBJECTIVE/UNASSIGNED:Mid-to-distal tracheal surgery for cancer can be safely performed minimally invasively with a one-day length of stay, avoiding a guardian chin suture, and ensuring a R0 resection in select patients. METHODS/UNASSIGNED:This is a retrospective technical review of the largest series to date of patients with mid-to-distal tracheal cancers. All were offered a right robotic approach using veno-venous extracorporeal membrane oxygenation (VV ECMO) support via percutaneous right internal jugular vein and right common femoral vein access. RESULTS/UNASSIGNED:From May 2019 to April 2024, five consecutive patients (3 men, 2 women; aged 11, 29, 37, 40, and 74 years) presented with a mid-to-distal tracheal cancer. All underwent right robotic mid-distal tracheal resections on VV ECMO for primary tracheal cancers. All patients had an end-to-end tracheal anastomosis and R0 resection and all avoided: systemic heparinization, suprahyoid release maneuvers and a postoperative guardian chin stitch. Median operative time was 258 min (range 227-292). All patients tolerated the operations well and were discharged home on the morning of postoperative day 1. There was no minor or major morbidity, no 30 or 90-day mortality, and no re-admissions. Two patients complained of cough. All had R0 resections and to date none have evidence of recurrent disease or stricture. CONCLUSION/UNASSIGNED:Resection of mid-to-distal primary tracheal cancers can be performed safely and efficiently via a right robotic approach while on VV ECMO with little to no morbidity or mortality and require only an overnight hospital stay. The techniques used to perform the operation and achieve these results are described.

We describe the case of a 36-year-old woman who underwent redo lung transplantation AFTER a heart-lung transplant 3.5 years prior. The retransplantation was performed through sequential left posterolateral thoracotomy followed by right anterior thoracotomy, without sternal division and without the use of extracorporeal membrane oxygenation or cardiopulmonary bypass support. The patient was found to have undergone an extensive pericardiectomy at the time of the initial heart-lung transplant. The patient recovered uneventfully and complete healing of the airway anastomosis was demonstrated. This novel technique avoids some potential pitfalls of redo lung transplantation after heart-lung transplant.

Lung cancer remains the leading cause of cancer-related deaths, with increased incidental nodules and a higher incidence in young female individuals. Effective screening and evaluation are vital for early lung cancer detection, while advancing imaging with radiomics and PET/computed tomography help assess the risk of malignancy. Nonsurgical diagnostic procedures include bronchoscopic and image-guided biopsy, while surgical biopsies for diagnosis can be aided by multiple intraoperative colocalization techniques. Accurate staging, particularly of lymph nodes, and molecular testing are essential for treatment planning and prognostication.

The benefits of bilateral lung transplantation (BLT) versus single lung transplantation (SLT) are still debated. One impediment to clinical recommendations is that BLT vs. SLT advantages may vary based on underlying disease. Since both options are clinically tenable in patients with emphysema, we conducted a comprehensive assessment of lung allograft survival in this population. Using U.S. registry data, we studied time to all-cause allograft failure in 8,092 patients 12 years or older transplanted from 2006 to 2022, adjusting for recipient, donor, and transplant factors by inverse propensity weighting. Median allograft survival was 6.6 years in BLT compared to 5.3 years in SLT, a 25% risk-adjusted survival advantage of _0.81.3_1.8 years. Risk-adjusted bilateral survival advantages varied between 0.9 and 2.4 years across eleven subgroups. Median allograft survival in BLT was 1.2 years greater than right SLT and 2.0 years greater than left SLT. During the 16-year study period, allograft survival steadily improved for BLT but not for SLT. Although the 25% BLT survival advantage pre-dated the pandemic, COVID-19 may have contributed to an apparent SLT survival decline. Recognizing the possible influence of residual confounding due to selection biases, these findings may aid offer decision-making when both donor lungs are available.