PO121 - A randomized controlled trial comparing the diagnostic yield of standard flexible bronchoscopy versus ultrathin bronchoscopy for bronchial mucosal biopsy in sarcoidosis
Sahajal Dhooria (India)1; Swagatha Jose (India)1; Amanjit Bal (India)2; Ritesh Agarwal (India)1;
1 - Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh; 2 - Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh;
Keywords: sarcoidosis; bronchial biopsy; ultrathin bronchoscopy;
Select the theme: Challenges in Sarcoidosis Diagnosis and Staging
Type: Original Papers
Presentation: Poster Presentation

Introduction: In pulmonary sarcoidosis, granulomatous inflammation may involve the larger airways in addition to the lung parenchyma and intrathoracic lymph nodes. Endobronchial biopsy (EBB) performed with a standard-sized flexible bronchoscope (SB) yields granulomas in 20-40% patients. The ultrathin bronchoscope (UTB), owing to its smaller outer diameter, can access more distal bronchi and may potentially improve the diagnostic yield of EBB. 

Objectives: To compare the diagnostic yield of EBB performed using UTB vs. SB in subjects with suspected sarcoidosis

Materials and Methods: We conducted an investigator-initiated single-center, parallel-arm, randomized trial. Consecutive subjects (≥18 years) with a clinicoradiological presentation consistent with sarcoidosis were randomized 1:1 to undergo EBB using UTB (intervention) or SB (control), with respective forceps used for tissue sampling. The primary outcome was the diagnostic yield of EBB, defined by the presence of granulomas, among subjects with a final diagnosis of sarcoidosis. Secondary outcomes included specimen size and the diagnostic yield of combined procedures: endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) with EBB, with or without transbronchial lung biopsy (TBLB).

Results: Fifty-six subjects were included (mean age, 45.5 years; 39.3% men), with 28 in each group. Visible endobronchial abnormalities were observed in 11 subjects (UTB, 4; SB, 7). SB yielded larger biopsy specimens than UTB (median diameter, 3 mm vs. 1 mm; p<0.001). Sarcoidosis was diagnosed in 42 subjects. The diagnostic yield of EBB was significantly lower with UTB than SB (4.8% vs. 42.9%; p=0.004). The yield of combined procedures was similar between groups: EBUS-TBNA+EBB (UTB vs. SB, 76.2% vs. 81.0%; p=1.00) and EBUS-TBNA+EBB+TBLB (85.7% in both groups; p=1.00). After adjustment for specimen size, group allocation was not independently associated with diagnostic yield (p=0.07).

Conclusions: Ultrathin bronchoscopy-guided EBB has a lower diagnostic yield than standard bronchoscopy in sarcoidosis, likely due to smaller biopsy specimens obtained with UTB.