[The efficacy and safety of transbronchial lung cryobiopsy in interstitial lung disease: a prospective study]

Objective: To evaluate the efficacy and safety of transbronchial lung cryobiopsy (TBCB) and conventional transbronchial lung biopsy (TBLB) in the diagnosis of interstitial lung diseases(ILD). Methods: A prospective, self-control study was conducted during January 2017 and April 2017 in First Affiliated Hospital of Guangzhou Medical University. A total of 25 patients [male 16, female 9; mean age (51±13) years, range 24 to 70 years] with inconclusive diagnosis of interstitial lung diseases were sequentially enrolled. In the study, TBCB (TBCB group) and TBLB (TBLB group) were performed successively under general anesthesia in all patients. The size of biopsy specimens, the duration of procedures, complications and pathological results were recorded. Gaussian distribution data were compared between 2 groups by using Student's t test, while abnormal distribution data were compared by using Wilcoxon rank sum test. The incidences of bleeding and pathologic diagnostic yield between the 2 groups were compared by using Pearson chi-square test. A P-value< 0.05 was assumed to be statistically significant. Results: The specimen sizes of TBCB group and TBLB group were (12.3+ 4.9) and (3.1+ 1.9) mm(2) respectively (t=-18.268, P=0.000). The duration of procedures was (7.8±3.2) and (5.4±2.1)min respectively (Z=-3.001, P=0.003). In TBCB group, the diagnostic yield was 72% (18/25), with valuable pathological results in 2 cases (8%), but in 5 cases (20%) it failed to provide valuable pathological results. In TBLB group, the diagnostic yield was 12% (3/25). There were no useful pathological results in other 22 cases. The difference in the rate of useful pathological results between TBCB group and TBLB group was significant (χ(2)=20.779, P=0.000). There was no pneumothorax or severe bleeding. The rate of mild to moderate bleeding in TBCB group and TBLB group was 47.2%(50/106) and 18.9%(20/106) (χ(2)=19.195, P=0.000) respectively. Conclusion: TBCB is superior to TBLB for lung biopsy as indicated by larger sample size, higher diagnostic yield and less complication. TBCB is valuable for the diagnosis of ILD.