Utility of Novel Flexible Ultrathin Cryoprobe in the Biopsy of Solitary Pulmonary Nodule

Abstract

<b>Introduction:</b> Adequate tissue sampling for lung cancer molecular profiling is essential in the era of targeted and immunotherapy. The ability of conventional cryoprobe to effectively acquire larger specimens from highly angulated regions within the lung is frequently hindered by its stiff nature. A novel flexible miniature cryoprobe may address this limitation. <b>Methods:</b> Retrospective case series of solitary pulmonary nodule (SPN) biopsy performed at two interventional pulmonology units in Malaysia using the novel flexible ultrathin cryoprobe. <b>Results:</b> Our cohort comprised of five patients with mean age of 67.2 (SD 7.7) years old. Mean SPN size was 2.37 (SD 0.19) cm. All procedures were performed with advanced airway under total intravenous anaesthesia with fluoroscopy guidance. 4/5 (80%) targets were eccentric while 1/5 (20%) was concentric in orientation after localization by rEBUS/GS. Conventional forcep biopsy was performed prior to cryobiopsy in all cases. Cryobiopsy was performed for a mean of 1.8 (SD 1.1) passes with 5 seconds of freeze time. Mean cryo-specimen aggregate size was 5.2 (SD 2.3) mm. Forcep biopsy concluded a definite diagnosis in 3/5 (60%) cases, cryobiopsy increase the diagnostic yield to 4/5 (80%). No complications were encountered in all cases. <b>Conclusion:</b> Flexible miniature cryoprobe can be a promising SPN biopsy tool. Further study to establish its diagnostic yield and safety is required.