Study of Transbronchial Cryobiopsy in Monitoring Complications of Lung Transplantation

Inclusion Criteria: * Age among 18-65 years old * After unilateral or bilateral lung transplantation, patient with unexplained pulmonary function decline, acute/chronic clinical lung injury or new pulmonary infiltrates * or patients requiring monitoring of rejection after lung transplantation * The patient should undertake routine preoperative examinations for lung cryobiopsy, including routine blood test, coagulation function, electrocardiogram, and chest CT, and the patients have no contraindications to cryobiopsy Exclusion Criteria: * patients intolerable to undertake lung biopsy due to severe cardiopulmonary insufficiency or being weak * The patient is allergic to lidocaine and midazolam * The patient has recent active massive hemoptysis, or the proposed biopsy site has a high risk of bleeding, such as bronchial artery penetration or suspected renal cancer lung metastasis * Unstable angina, congestive heart failure, severe bronchial asthma or multiple bullae * Severe hypertension and arrhythmia, hemodynamic instability and severe respiratory failure (PaO2\<60mmHg after oxygen therapy or mechanical ventilation) * The patient has coagulation disorder and unable to stop taking anticoagulants, antiplatelet drugs, aspirin or non-steroidal anti-inflammatory drugs before lung biopsy * Suspected aortic aneurysm * The patient does not agree to participate in this study * Participating in other studies within three months and not withdrawing or ending * The researchers think that the patient are not suitable for inclusion