Evaluation of histological specimens obtained by two types of EBUS-TBNA needles: a comparative study

Background: Endobronchial ultrasound-guided transbronchial needle aspiration is a standard method for obtaining specimens of mediastinal and hilar lesions. Several types of needles of various sizes and materials are available. This study aimed to compare the quality of specimens collected using two needles, cobalt chromium and stainless steel for endobronchial ultrasound-guided transbronchial needle aspiration.

Methods: This retrospective study included data of patients who underwent EBUS-TBNA with a 22-gauge needle made from either stainless steel (41 lesions, 121 punctures) or cobalt chromium (47 lesions, 145 punctures). Histological data per puncture, diagnostic yield per lesion, procedure time and complication rates were compared.

Results: There were no significant differences between the groups in the baseline characteristics of the patients or lesions or in the complication rates. The rate of diagnostic histological specimens in each sample (71.0% vs. 58.7%, P = 0.039), fewer samples with cartilage alone (1.4% vs. 6.6%, P = 0.047) and fewer samples containing cartilage (7.6% vs. 16.5%, P = 0.034) were seen in the cobalt chromium needle group than in the stainless steel needle group. In both groups, the rate of specimens that only contained blood clots in each sample and diagnostic yield per lesion were similar, but the procedure time was significantly shorter (22 min vs. 26 min, P = 0.007) in the cobalt chromium needle group.

Conclusion: Compared with stainless steel needles, cobalt chromium needle for EBUS-TBNA showed lower cartilage contamination and a higher ratio of obtaining diagnostic specimens in each sample. Bronchoscopists should consider using the optimal needle gauges and materials for collecting adequate specimens.