Clinical Effectiveness of a Balloon Covered Sheath as a Guide Sheath in Endobronchial Ultrasound Guided Diagnosis of Peripheral Lung Lesions

Flexible bronchoscopy has been applied in the diagnosis of peripheral pulmonary lesions (PPLs) for decades. Without accurate localization, the diagnostic yield for peripheral lung cancers by these procedures is limited and variable. Localization of peripheral lung cancers can be aided by the use of computed tomography or fluoroscopy during fiberoptic bronchoscopy. However, radiation exposure to staffs and patients is always a concern in these procedures.

The clinical application of endobronchial ultrasound (EBUS) included determination of the depth of tumor invasion in tracheobronchial wall, evaluation of tracheobronchial structure before therapeutic bronchoscopy, localization of site of biopsy, EBUS-guided transbronchial needle aspiration, and analysis of peripheral tumor. Under EBUS guidance, the diagnostic yield of transbronchial lung biopsy in patients with peripheral lung cancer by bronchoscopic examination was significantly improved without an increase in the complication rate. More recently, with the aid of a guide sheath (EBUS-GS), EBUS has been shown to increase the diagnostic yield of PPLs, even in patients with fluoroscopy-invisible lung nodules, and avert the need for surgical procedures.

Most recently used GS for EBUS are specified for the EBUS probe with an external diameter of 1.9 mm. Such a thin caliber GS is designed to reach the PPLs, sometimes with an aid of curette, to provide an exact site for repeated obtainment of adequate specimens. We wonder whether a larger caliber sheath transformed from a balloon covered with an external diameter of 2.6 mm without reaching the PPLs, can offer similar effectiveness in diagnosis of the PPLs. The results may provide an alternative way for EBUS-GS especially in those countries where the commonly used GS of EBUS is not available.