Comparison of the diagnostic yield of transbronchial lung biopsies by forceps and cryoprobe in diffuse parenchymal lung disease

BACKGROUND: Transbronchial lung cryobiopsy (TBLC) in the diagnosis of diffuse parenchymal lung disease (DPLD) has shown a promising yield in recent times, with low post-procedural mortality and morbidity. OBJECTIVES: To compare the yield of TBLC and conventional transbronchial forceps lung biopsy (TBLB). METHODS: A prospective study was carried out in patients with DPLD over a period of 1 year in a tertiary respiratory care institute in New Delhi, India. All 87 patients enrolled underwent both TBLB and TBLC. The procedures were performed in the bronchoscopy suite under conscious sedation and local anaesthesia, with an attempt to take a minimum of three biopsy specimens by conventional TBLB followed by TBLC. A 1.9 mm cryoprobe with a freezing time of 4 - 5 seconds was used. An Arndt endobronchial blocker was used to control bleeding along with locally administered medications. RESULTS: TBLB and TBLC led to a definitive diagnosis in 27 (31.0%) and 69 (79.3%) cases, respectively. The commonest diagnoses were hypersensitivity pneumonitis, sarcoidosis and pulmonary tuberculosis. TBLC led to additional diagnoses in 42 cases (48.3%). Pneumothorax was observed in 12 cases (13.8%), and moderate bleeding occurred in 63 (72.4%). There were no procedure-related deaths. CONCLUSION: TBLC had a better diagnostic yield than conventional TBLB in DPLD. It has the potential to become a safe day-care procedure in a resource-limited setting, if certain precautions are taken. STUDY SYNOPSIS: What the study adds. Compared with transbronchial forceps lung biopsy, transbronchial lung cryobiopsy (TBLC) led to additional diagnoses in 42 (48.3%) of 87 patients with clinicoradiological features of diffuse parenchymal lung disease. Pneumothorax was observed in 12 cases (13.8%) and moderate bleeding in 63 (72.4%). TBLC without rigid bronchoscopy or advanced airway devices under conscious sedation had a good diagnostic yield with an acceptable adverse events profile. Implications of the findings. TBLC under conscious sedation is not resource intensive and can be carried out in settings with limited resources.