A Closer Look at Risk Factors Associated with Airway Complications in Lung Transplantation

Abstract

Purpose Airway complications can cause significant morbidity in lung transplantation; prevalence varies between 8-20%. In 2018, the ISHLT created a new grading system for airway complications. This study s aim was to grade airway complications using the new system and identify associated risk factors including the use of ex-vivo lung perfusion (EVLP). Methods This was a retrospective, single-center study of 188 lung transplants done between Feb 2016 and Mar 2020. Clinically significant airway ischemia (CSAI) was defined as ischemia severity equal to or worse than grade B2, > 50% stenosis, or dehiscence. EVLP was performed using the Organ Care System (OCS) Lung, in the setting of extended criteria donors (ECD) which included any combination of the following: age >55 yrs, > 6-hr ischemia, death from circulatory arrest, >20 pack-yr smoke history, or PF ratio Results 188 recipients or 339 lung allografts were transplanted within the study period. The average age was 52.4 years; 58% were male. Out of 339 lung allografts, 116 (34%) met criteria for CSAI. 15.3% of allografts were preserved using EVLP and of these, 88.5% were ECD. Recipients with diabetes mellitus were more likely to have CSAI than those without (OR 2.46, p value\u202f=\u202f0.04). CSAI was associated with several factors in the unadjusted analysis including EVLP (OR 1.65, 95% CI 0.90-3.01), continuous running suture technique versus interrupted suture technique (OR 1.84, 95% CI 1.05-3.33), right versus left allograft (OR 1.41, 95% CI 0.90-2.21), right versus left side of first anastomosis (OR 0.71, 95% CI 0.45-1.11) and extracorporeal life support (ECLS) versus off-pump (OR 1.77, 95% CI 0.93-3.41). In particular, 23 of the 52 (44%) of the lung allografts performed with EVLP had CSAI compared to 93 of the 287 (32%) allografts procured traditionally. CSAI was significantly associated with EVLP (OR 1.98, 95% CI 1.05-3.76) and continuous running suture technique (OR 2.00, 95% CI 1.05-3.94) after adjusting for recipient, donor and intraoperative factors. Conclusion A high burden of CSAI was detected in our study. Analysis suggests that ECD lungs preserved with EVLP may be at higher risk of CSAI than donor lungs preserved on ice, but use of interrupted suture technique and avoidance of ECLS may reduce this risk.