Diagnostic Yield of Thin vs Ultrathin Bronchoscope for Peripheral Pulmonary Lesions

For the diagnosis of small peripheral pulmonary lesions, navigational endobronchial ultrasonographic bronchoscopy using a 3.0-mm ultrathin bronchoscope (UTB) provides a higher diagnostic yield than using a 4.0-mm thin bronchoscope, according to the results of a study published in CHEST.¹

Recent modifications of bronchoscopic techniques, such as the use of radial-probe endobronchial ultrasound, navigation devices, and UTBs, have markedly improved the diagnostic yield of bronchoscopy for peripheral pulmonary lesions, especially when these ancillary techniques are combined rather than using each technique alone.¹ A previous study demonstrated that a 3.0-mm UTB with a 1.7-mm working channel is advantageous with regard to good access to the peripheral airway, whereas a 4.0-mm thin bronchoscope provides a larger 2.0-mm working channel, which allows the use of various instruments including a guiding sheath, larger forceps, and an aspiration needle.²

However, the diagnostic performance of bronchoscopy using a thin bronchoscope may have been underestimated in that study, therefore researchers conducted another study to compare the diagnostic yield of bronchoscopy using a UTB to that using a thin bronchoscope and multiple sampling devices for the diagnosis of small peripheral pulmonary lesions.¹

A total of 360 patients were assigned to either the UTB or thin bronchoscope group. The median lesion size was 19.0 mm, with a range between 7.4 mm to 30.0 mm. The overall diagnostic yield was significantly higher in the UTB group than in the thin bronchoscope group (70.1% vs. 58.7%, respectively; P =.027), and the procedure duration was significantly shorter in the UTB group (median 24.8 vs. 26.8 min, respectively; P =.008). In addition, complication rates were 2.8% and 4.5% in the UTB and thin bronchoscope groups, respectively (P =.574).

Several study limitations were noted. Procedures were conducted only at centers of expertise, meaning that the results may not be generalizable to other facilities with less experienced staff. More importantly, the UTB used was a prototype, so the findings should be considered experimental. (The UTB has since been released commercially, but its availability is limited.) The final diagnoses were not pathologically confirmed in all patients.

“[I]n patients with small peripheral pulmonary lesions, the use of a 3.0-mm UTB during multimodal bronchoscopy resulted in significantly higher diagnostic yield and shorter procedure duration without affecting safety compared to that using a 4.0-mm [thin bronchoscope] with multiple sampling methods, including [transbronchial needle aspiration] and [guide sheath]/non-[guide sheath] methods,” the authors wrote.¹

References

1. Oki M, Saka H, Asano F, et al. Use of an ultrathin versus thin bronchoscope for peripheral pulmonary lesions: a randomized trial [published online July 26, 2019]. CHEST. doi:10.1016/j.chest.2019.06.038

2. Oki M, Saka H, Ando M, et al. Ultrathin bronchoscopy with multimodal devices for peripheral pulmonary lesions. A randomized trial. Am J Respir Crit Care Med. 2015;192(4):468-476.