Pulmonary infectious complications associated with the addition of cryobiopsy to conventional sampling for peripheral pulmonary lesions: a retrospective study

Background Cryobiopsy is used in addition to conventional sampling during endobronchial ultrasound (rEBUS)-guided bronchoscopy for peripheral pulmonary lesions (PPLs) to improve diagnostic yield. However, the incremental risk of procedure-related pulmonary infection remains poorly quantified in routine clinical practice. Methods We retrospectively analyzed consecutive patients who underwent rEBUS-guided bronchoscopy for PPLs between January 2019 and March 2022; 268 patients underwent combined conventional biopsy and cryobiopsy, and 1,497 underwent conventional biopsy alone. Pulmonary infectious complications occurring within 4 weeks after bronchoscopy were assessed. To adjust for baseline differences, propensity score matching was conducted. The association between biopsy strategy and pulmonary infectious complications was evaluated. Absolute risk difference and number needed to harm were calculated, and a sensitivity analysis using overlap weighting was conducted. Results After propensity score matching, 756 patients were included in the matched cohort (combined cryobiopsy group: n = 252; conventional biopsy group: n = 504). Pulmonary infectious complications occurred more frequently in the combined cryobiopsy group than in the conventional biopsy group (4.8% vs. 1.8%). Adding cryobiopsy was associated with an increased risk of pulmonary infectious complications (odds ratio, 2.84; 95% confidence interval, 1.15–6.99; P = 0.023), corresponding to an absolute risk increase of 3.0% and a number needed to harm of 33. These findings were consistent in sensitivity analyses using overlap weighting. Conclusions Adding cryobiopsy to conventional sampling in rEBUS-guided bronchoscopy was associated with a higher risk of pulmonary infectious complications. These findings provide quantitative evidence to guide patient selection and procedural planning.