Rendimiento diagnóstico y complicaciones de la criobiopsia transbronquial en trasplantados pulmonares

Abstract

Lung transplant is the last therapeutic option in some terminal pulmonary diseases. It is known that lung transplant may have several complications, being one of the most frequent the lung rejection. An early diagnosis and treatment of this complication have an important impact in its evolution. Due to the importance of the early diagnosis of lung rejection, new techniques such as the transbronchial cryobiopsy have been developed in the last years. Transbronchial cryobiopsy has demonstrated to be superior in terms of performance than transbronchial forceps biopsy. Therefore, this thesis aims to investigate the possible role of transbronchial cryobiopsy in the diagnostic algorithm of complications after lung transplant. The main interests of this thesis were evaluated, through two prospective studies and a randomized clinical trial, 1) the minimum necessary transbronchial cryobiopsies to accomplish a high diagnostic performance; 2) the radiological characteristics and evolution of new opacities in chest CT after performing transbronchial cryobiopsies; 3) the diagnostic effectiveness and safety of transbronchial cryobiopsies in critically ill patients intubated in the Intensive Care Unit (ICU). In the first study of this thesis three hundred and twenty-one consecutively transbronchial cryobiopsies were performed in 206 patients and at least 6 samples were obtained per procedure. Results showed that obtaining at least 4 samples per procedure improves the histological diagnostic accuracy (p < 0. 001) without increasing significantly severe complications. Moreover, our study demonstrated that being unilateral lung transplant recipient (odds ratio, 0. 10; CI of 95%, 0. 02-0. 30; p<0. 001) or presenting arterial hypertension during the procedure (odds ratio, 0. 31; CI of 95%, 0. 12-0. 86; p=0. 019) seem to be risk factors associated with increased bleeding during the bronchoscopy. In the second study, fifty-one patients were consecutively recruited and only 22 were included. Previously to transbronchial cryobiopsies a chest CT was performed, as well as after 1, 4 and 8 weeks from the procedure. Out of the 22 patients included, 20 (91%) presented 46 opacities larger than 10mm in the post procedure chest CT. These new opacities were defined as either ground glass opacities, solid or cavitated lesions or a combination of both. The ground glass opacities disappeared after four weeks from the procedure and only one cavitated lesion persisted after 6 months from the transbronchial cryobiopsy. Therefore, our study concludes that a pre and post procedure chest CT should be performed when available. Finally, the third study evaluated the diagnostic effectiveness and safety of transbronchial cryobiopsy in critically ill intubated patients from the ICU. Patients were randomly selected in order to carry out either a transbronchial biopsy with biopsy forceps, or cryoprobe of 1. 9mm or cryoprobe of 2. 4 mm. A total of 89 procedures were performed, showing that using a cryoprobe of 2. 4 mm had a superior diagnostic effectiveness when compared to cryoprobe of 1. 9 mm (p=0. 02) and biopsy forceps (p<0. 001). No bleeding events or severe complications were observed.

Date of Award	28 Nov 2023
Original language	Spanish
Supervisor	Javier de Gracia Roldan (Director)