Abstract:Objective To evaluate the clinical value of narrow-band imaging (NBI) combined with pleural cryobiopsy in the diagnosis of unexplained pleural effusion.Methods 113 patients with unexplained pleural effusion were examined by medical thoracoscopy. During the examination, the pleural surface was observed by white light thoracoscopy, then the pleural surface was observed by NBI. The morphological manifestations of different lesions under white light thoracoscopy and NBI were analyzed. Routine clamp biopsy and cryobiopsy were performed on the suspected lesions on the pleural surface under white light and NBI, respectively. The diagnostic rate, sensitivity, specificity and lesion diameter of the two groups were compared, and the safety and complications of different biopsy methods were analyzed.Results The sensitivity, specificity and diagnostic rate of pleural diseases in NBI combined with cryobiopsy group were higher than those in white light combined with cryobiopsy group, and there were significant differences between the two groups. The diagnostic sensitivity and diagnostic rate of pleural diseases in NBI combined with clamp biopsy group were higher than those in white light combined with clamp biopsy group. There was significant difference in sensitivity between the two groups (P = 0.033), but there was no significant difference in diagnostic rate between the two groups (P = 0.079). The specificity of NBI combined with clamp biopsy group was significantly lower than that of white light combined with clamp biopsy group, and the difference was statistically significant (P = 0.041). The abundance of blood vessels on the pleural surface was analyzed by NBI. The sensitivity, specificity and diagnostic rate of cryobiopsy with more than 2 diseased vessels were 97.56%, 83.33% and 95.74%, respectively, which were higher than those with less than 2 diseased vessels. The diameters of clamp biopsies and cryobiopsies were compared. The results showed that the diameters of the two groups were (1.87 ± 0.10) and (27.16 ± 4.33) mm, respectively, and there was significant difference between the two groups (t = -5.84, P = 0.000).Conclusion Medical thoracoscopic NBI combined with pleural cryobiopsy can improve the sensitivity, specificity and diagnostic rate of unexplained pleural effusion, and has high safety, it is worthy of clinical application.