A Systematic Review of Transbronchial Lung Cryobiopsy for Pediatric Interstitial Lung Diseases.

Background: Surgical lung biopsy (SLB) is the standard for diagnosing pediatric interstitial lung diseases (ILDs). However, transbronchial lung cryobiopsy (TBLC) is emerging as a less invasive alternative. We aim to systematically review the efficacy and safety of TBLC in pediatric ILDs.

Methods: PubMed and Embase databases were searched from inception to December 7, 2023, for TBLC studies in pediatric ILDs. Data on demographics, diagnoses, procedure details, histopathology, diagnostic yield, and complications were collected.

Results: We retrieved 2093 citations and included 61 patients (age [range] 12 days to 17 years) from eight studies. Pulmonary alveolar proteinosis, sarcoidosis, and non-specific interstitial pneumonia were the common clinico-radiological diagnoses. Rigid bronchoscopy (median size, 6.5 [range, 3.5-11] mm) was used as a conduit in 46% of subjects. The median (range) outer diameter and channel diameter of the flexible bronchoscope were 4.2 (2.8-6.2) mm and 2 (1.2-2.2) mm, respectively. The median (range) size of the cryoprobe used was 1.9 (1.1-2.4) mm, and the median (range) of biopsies per patient was 3 (1-5). TBLC's diagnostic yield was 91.8% (95% CI [82.2 to 96.4]), and the rate of major complications (moderate to severe bleeding, pneumothorax requiring intercostal chest tube drainage, exacerbation of ILD, care escalation, or death) was 6.5% (n = 4).

Conclusion: TBLC offers a high diagnostic yield comparable to SLB while being less invasive. However, this systematic review is limited by small sample size, non-standardized protocols, and lack of comparative trials. Further studies are needed to establish TBLC as a viable alternative to SLB in pediatric ILDs.