Diagnostic Utility and Safety of Non-Intubated Cryobiopsy Technique Using a Novel Ultrathin Cryoprobe in Addition to Conventional Biopsy Techniques for Peripheral Pulmonary Lesions

Abstract

<b><i>Background:</i></b> Transbronchial cryobiopsy enables high-quality sample collection around the probe tip. Meanwhile, existing cryoprobes have less flexibility and a higher risk of bleeding. The ultrathin cryoprobe with a 1.1-mm diameter addresses these problems and allows specimens to be directly retrieved through the working channel of a thin bronchoscope. <b><i>Objective:</i></b> This study evaluated the diagnostic utility and safety of non-intubated cryobiopsy using an ultrathin cryoprobe added to conventional biopsy for diagnosing peripheral pulmonary lesions (PPLs). <b><i>Methods:</i></b> The data of patients who underwent conventional biopsy followed by non-intubated cryobiopsy to retrieve specimens through the thin bronchoscope’s working channel for diagnosing PPLs at Osaka Metropolitan University Hospital from July 2021 to June 2022 were retrospectively collected. They were analyzed to evaluate the diagnostic utility and safety of adding non-intubated cryobiopsy to conventional biopsy for PPLs. The characteristics of PPLs that obtain additional diagnostic benefits from cryobiopsy over conventional biopsy were also investigated. <b><i>Results:</i></b> The analysis included 113 patients. The diagnostic yields of conventional biopsy and non-intubated cryobiopsy were 70.8% and 82.3%, respectively (<i>p</i> = 0.009). The total diagnostic yield was 85.8%, higher than conventional biopsy alone (<i>p</i> &lt; 0.001). Although one moderate bleeding occurred, no severe complications developed. The additional diagnostic benefits of non-intubated cryobiopsy over conventional biopsy were demonstrated when the radial endobronchial ultrasound (R-EBUS) showed “adjacent to” (60.3% vs. 82.8%, <i>p</i> = 0.017). <b><i>Conclusions:</i></b> Non-intubated cryobiopsy using an ultrathin cryoprobe has high diagnostic utility and safety for diagnosing PPLs, with additional diagnostic benefits over conventional biopsy depending on the R-EBUS image.