W. Ji*a (Prof), JH. Jeongb (Prof), H. Kimc (Prof), HJ. Parka (Prof), MA. Kimd (Prof), CM. Choia (Prof)

a Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea, Seoul, KOREA, REPUBLIC OF ; b Division of Pulmonology and Allergy, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, South Korea, Jinju, KOREA, REPUBLIC OF ; c Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Kangdong Sacred Heart Hospital, Seoul, Republic of Korea, Seoul, KOREA, REPUBLIC OF ; d Division of Pulmonary, Department of Internal Medicine, Dongsan Hospital, Keimyung University College of Medicine, Daegu, Republic of Korea, Daegu, KOREA, REPUBLIC OF

* wonjujnji@amc.seoul.kr

Background: Although bronchoscopic cryotherapy (BC) is a pragmatic modality for recanalization of central airway obstruction (CAO), the risk of bleeding complications is still the concerning point. This study aimed to present the clinical outcomes of BC and evaluate the factors associated with complication.

Methods: In this retrospective study, we reviewed the medical records of patients who underwent BC for CAO at Asan Medical Center, South Korea. Most sessions were conducted via flexible bronchoscopy under moderate sedation with local anesthesia. A multivariate logistic regression analysis was used to identify risk factors for complication.

Results: A BC was performed 262 sessions in 208 patients between January 2009 and December 2020. The most common cause of cryotherapy was recanalization of endobronchial tumor related CAO (233 of 262, 88.9%). More than partial reestablishment of airway patency were achieved in 212 out of 233 sessions (91.0%), symptoms relief after cryotherapy was found in 83 out of 110 sessions (75.5%), and a recurrence was reported in 72 of 233 sessions (30.9%). Most common complication was intrabronchial bleeding (78 of 233, 35.5%), but severe bleeding occurred only in 1 case (0.4%). One patient died of severe bleeding and respiratory failure after cryorecanalization. Univariate and multivariate logistic regression analysis revealed that diabetes mellitus (OR 2.466, 95% CI 1.136-5.353, p=0.022) and respiratory failure before BC (OR 3.046, 95% CI 1.015-9.139, p=0.047) were independently associated with moderate to severe complication, while histologic type of tumor was not related to bleeding. BC for CAO caused by blood clot or foreign body was successful in all cases, and there were no complications.

Conclusions: Bronchoscopic cryotherapy is an efficient and relatively safe interventional procedure for patients with CAO. Our finding suggested that diabetes and respiratory failure before cryotherapy might be a risk factor of moderate to severe bleeding complication.

Disclosure of funding source(s): none