No abstract

BackgroundRadial endobronchial ultrasound (R-EBUS) is an effective technique in the diagnosis of peripheral pulmonary lesions (PPL). However, lesion orientation with regards to the radial probe remains an important factor for effective biopsy. “Within” orientation was associated with significantly higher diagnostic yield. Cryobiopsy is a novel technique in obtaining larger tissue samples with the frozen tip allowing biopsy in a 360° direction, thus potentially achieving more effective biopsy in eccentrically and adjacently orientated lesions. We aimed to evaluate the performance and safety of transbronchial cryobiopsy versus forceps biopsy in eccentrically and adjacently orientated R-EBUS lesions.MethodsRetrospective review of R-EBUS transbronchial biopsy for PPL over 17 months.Results114 R-EBUS scans were included for analysis during the study period. Forceps biopsy was performed in 76 (66.7%) cases and cryobiopsy in 38 (33.3%) cases. Baseline demographics and lesion characteristics did not differ between the two groups. Median (interquartile range) lesion size was 3.48 (2.63–4.51) cm. Overall, 41.2% of lesions were of eccentric orientation and 15.8% adjacent orientation; only 43% were concentric in orientation. Overall diagnostic yield was 67.5% (77 out of 114). Orientation remained an important factor affecting diagnostic yield. Transbronchial cryobiopsy significantly increased the diagnostic yield in eccentrically and adjacently orientated lesions to 75.0% (18 out of 24), compared to 48.8% (20 out of 41) obtained via forceps biopsy (p<0.05); but not in concentric lesions. Cryobiopsy was associated with more mild and moderate bleeding complications compared to the forceps biopsy group.ConclusionsTransbronchial cryobiopsy under R-EBUS guidance is a safe procedure which potentially increases diagnostic yield in eccentrically and adjacently orientated PPLs.

Background: Lung cancer is frequently situated peripherally in the upper lobes of the lung. Acquiring adequate tissue from this difficult-to-reach area remains a challenge. Transbronchial cryobiopsy (TBCB) has the ability to acquire larger specimens, but the rigidity of the standard 1.9 mm and 2.4 mm cryoprobes frequently poses challenges when used with a guide sheath (GS). The novel 1.1 mm cryoprobe, being both smaller and more flexible, may address this limitation. We describe the usage of this 1.1 mm flexible cryoprobe with GS in the biopsy of solitary pulmonary nodules (SPN) in the apical segment of the upper lobe in two cases. Case report: Both procedures were conducted with advanced airway under total intravenous anaesthesia. 2.6 mm GS was used in combination with a 2.2 mm rEBUS probe, using a therapeutic bronchoscope. Case 1 describes a SPN in the apical segment of the right upper lobe that was inconclusive by forceps biopsy due to GS displacement and inadequate biopsy depth. A steerable GS combined with the novel cryoprobe subsequently overcame this issue. Case 2 describes a SPN in the apical segment of the left upper lobe in which the standard cryoprobe failed to advance through the GS due to steep angulation. It also highlights with shorter activation time, the novel cryoprobe enable biopsied tissue to be retrieved through the GS while the bronchoscope-GS remains wedgend in the airway segment. There were no bleeding or pneumothorax complications in both cases, and histopathological examination confirmed adenocarcinoma of the lung. Conclusion: The 1.1 mm flexible cryoprobe in combination with GS and therapeutic bronchoscope offers an option to acquire adequate tissue in difficult-to-reach regions in the lung such as the apical segment of upper lobes. Further prospective series to evaluate its performance and safety in SPN biopsy is highly anticipated.