Assessment of using radial probe endobronchial ultrasound with a guide sheath to increase the yield rate of transbronchial biopsy: A prospective randomized trial

Assessment of using radial probe endobronchial ultrasound with a guide sheath to increase the yield rate of transbronchial biopsy: A prospective randomized trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Assessment of using radial probe endobronchial ultrasound with a guide sheath to increase the yield rate of transbronchial biopsy: A prospective randomized trial Hao-Chun Chang, Yao-Wen Kuo, Ching-Kai Lin, Lih-Chyun Chang, You-Yi Chen, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3824206/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Radial probe endobronchial ultrasound (rEBUS)-guided transbronchial biopsy (TBB) with a guide sheath (GS) is widely used to diagnose peripheral lung lesions (PPLs), but there is no consensus on whether it increases the diagnostic yield. We conducted this prospective study to compare the diagnostic yield of the GS method to the conventional method without a GS. Material and methods From November 2019 to March 2023, patients with PPLs were recruited and randomly assigned to rEBUS-TBB with a GS (GS group) or without a GS (conventional group). The histopathology, cytology, and microbiology yield rates, as well as procedure time and post-procedure adverse events of the two groups were compared. Results A total of 102 patients were enrolled (54 in the GS group and 48 in the conventional group). The GS group exhibited a trend of increased pathology yield (75.9% vs. 68.8%, p = 0.418), while the yield rates of brushing cytology (64.3% vs. 42.9%, p = 0.030) and washing cytology (41.5% vs. 20.0%, p = 0.0443) were higher in the GS group. Meanwhile, the yield from GS washing culture was lower than the bronchial washing culture yield (0% vs. 57.1%, p = 0.017). The bleeding risk was also lower in the GS group (9.3% vs. 20.8%, p = 0.049), but the procedure time was longer in the GS group (17.6 ± 4.7 min vs. 15.1 ± 4.5 min, p = 0.008). Conclusion rEBUS TBB with a GS can increase the diagnostic yield of PPLs and decrease the risk of bleeding, while additional bronchial washing should be utilized to increase the microbiology yield. Trial registration: The study was registered at Clinicaltrials.gov (NCT04056273). radial probe endobronchial ultrasound transbronchial biopsy guide sheath diagnostic yield cytology Introduction Bronchoscopy is a commonly used diagnostic tool for peripheral pulmonary lesions (PPLs), but its diagnostic yield varies widely among studies.( 1 – 4 ) To improve the diagnostic yield, the use of radial probe endobronchial ultrasound (rEBUS) during bronchoscopic transbronchial biopsy (TBB) has been recommended in The American College of Chest Physicians Guidelines for Diagnosis and Management of Lung Cancer (3rd edition).( 5 ) rEBUS helps localize the lesions, and the bronchi leading to them; however, its major limitation is that real-time views are not obtained. This means that TBB and rEBUS scanning cannot be performed simultaneously, making it difficult to confirm that the biopsy instrument has been advanced through the bronchial route taken by the rEBUS probe to the target lesion.( 6 ) To overcome this limitation, Kurimoto et al.( 7 ) introduced the concept of rEBUS-guided TBB with a guide sheath (GS), which aimed to enhance the diagnostic accuracy of PPLs. This method involves inserting the ultrasound probe into the GS, extending it into the bronchoscopy working channel, reaching the lesions, removing the ultrasound probe while keeping the GS in place, and then inserting the biopsy forceps through the GS to obtain appropriate tissues. This has been found to be useful by many investigators.( 7 – 16 ) However, the use of a GS imposes a size limitation on the sampling instruments, while rEBUS-TBB without a GS (the conventional method) allows the use of larger biopsy forceps that may improve the diagnostic yield.( 17 ) Furthermore, the conventional method, which involves collecting multiple biopsies from various locations, has been hypothesized to increase the chance of obtaining at least one diagnostic sample compared to using the fixed location of the GS method.( 18 ) The GS method has some disadvantages, including technical complexity, possible displacement by coughing or deep respiration, and instrumental issues like kinking or bending of the GS and resistance during the advancing of biopsy instruments.( 19 – 23 ) The diagnostic yield of rEBUS-TBB with and without a GS has been the subject of only a few small comparative studies, and the use of a GS during rEBUS-TBB remains controversial. Therefore, we conducted this prospective randomized controlled study to compare the diagnostic yield of rEBUS-TBB with a GS to the conventional method. In addition, we also compared the microbiological culture results of two different specimen collection methods for those with the final diagnosis of pneumonia and mycobacterial infection. Materials and Methods Study patients This study was conducted at National Taiwan University Hospital (NTUH), a university teaching hospital with 2500 beds in northern Taiwan. From November 2019 to March 2023, patients with PPLs on a computed tomography (CT) scan were recruited and randomly assigned to rEBUS-TBB with a GS (GS group) or without a GS (conventional group). Randomization was stratified by lesion size (greatest diameter < 20 or ≥ 20 mm on CT scans), distance from the hilum (in the peripheral two-thirds or central one-third of the CT lung field), and rEBUS image type (concentric or eccentric). Allocations were performed electronically at a 1:1 ratio. The inclusion criteria were adult patients (age ≥ 20 years old) with PPLs requiring diagnosis that could be found by rEBUS. The exclusion criteria were B1 (RB1 & LB1/2) and B6 lesions, which were difficult for the GS to approach. The study was approved by the Institutional Review Board of NTUH (201904072RINC) and was registered at Clinicaltrials.gov (NCT04056273). All included participants provided written informed consent. Bronchoscopic procedure Most of the patients underwent bronchoscopic procedures under local anesthesia with clear consciousness. Some patients (about 17%) were given intravenous general anesthesia due to personal preference, although intravenous general anesthesia for bronchoscopy was not covered by Taiwan’s national health insurance program. The standard 4.8-mm bronchoscope, with a 2.0-mm working channel (BF-Q290; Olympus), was used for the majority of patients (about 80%), while therapeutic scopes, with a 5.9-mm width and 3.0-mm working channels (BF-1TQ290; Olympus), and thin scopes, with a 4.2-mm width and 2.0-mm working channels (BF-P290; Olympus), were the other options. After the bronchoscope reached the segment of the lesion, localized by CT scan, a 1.4-mm diameter rEBUS probe (UM-S20-17S; Olympus) was advanced through the working channel toward the lesion. When the target lesion was found by rEBUS, the distance from the segment orifice was measured. For the GS group, the rEBUS probe was reinserted again with a GS (K201 or K203; Olympus; depending on the working channel size of the scope used). GS was then deployed at the target lesion, and forceps biopsy as well as cytology brushing, from the GS kit, were done within the GS. After sampling, the GS was retrieved from the working channel, and 25 ml saline was used to irrigate the GS for the bronchial washing sample. As for the conventional group, a 2.0-mm biopsy forceps (FB-231D; Olympus) and a 2.0-mm cytology brush (BC-202D-2010; Olympus) were used, and bronchial washing was also performed after sampling. Biopsy was taken at least six times for each group. Microbiological cultures of biopsy tissue were also performed for those whom infectious disease was suspected. Rapid on-site cytological evaluation (ROSE) was not performed for either group. Evaluation parameters The primary end-point was the histopathological diagnostic yield of the allocated group. The secondary end-points included procedure time, frequency of complications, bronchial brushing and washing cytology yield, microbiological culture yield, and diagnostic yield stratified by malignancy or not, the lesion’s location, lesion size, and rEBUS image pattern. A positive diagnostic yield was considered to be obtained when the pathology report showed malignant or benign neoplasms, granulomatous inflammation, organizing pneumonia, and fungus or acid-fast positive microorganisms. The non-diagnostic yield included benign lung tissue, non-specific fibrosis, and chronic inflammation. These patients were followed up for at least six months, until the final diagnoses were established, based on pathological evidence, microbiological culture results, and radiological images. If pneumonia was the clinical diagnosis and the lesion did resolve completely during follow-up, inflammation from the initial pathology report would also be considered as a positive diagnosis. As to the microbiological study, the culture results of the specimen from the GS irrigation were compared with the bronchial washing fluid in the conventional group. Statistical analysis The Pearson Chi-squared test was used for categorical variables comparison, while Fisher's exact mid-P test was used when necessary. Continuous variables were expressed as mean ± standard deviation (SD), and were compared using Student’s t-test. P values less than 0.05 were considered statistically significant. All statistical analyses were conducted using SAS version 9.4 (SAS Institute, Cary, NC, USA). Results During the study period, 102 of the 1309 patients that underwent rEBUS-TBB were enrolled in the study. The baseline characteristics of the patients, their lesions, and their bronchoscopic findings are listed in Table 1 . All 102 patients had a positive CT bronchus sign. More than half of the patients in the GS group (61.1%) and half in the conventional group (50.0%) had centrally located lesions (p = 0.259). The majority of the lesions were more than 2 centimeters in diameter (GS vs. conventional: 90.7% vs. 91.7%, p = 0.869). Only a few patients underwent the procedure with BF-1TQ290 (with a 3.0 mm working channel) (GS vs. conventional: 5.6% vs. 12.5%, p = 0.217). The final diagnoses of the patients are shown in Table 2 . The majority of the diagnoses were malignancy (GS vs. conventional: 81.5% vs. 79.2%, p = 0.769), especially lung cancer (GS vs. conventional: 86.4% vs. 92.1%, p = 0.402). Table 1 Characteristics of the patients and their lesions Guide Sheath (n = 54) Conventional (n = 48) P value Age (mean ± SD) 65.8 ± 13.9 66.6 ± 10.7 0.769 Sex (Male) Male 34 (63.0%) 30 (62.5%) 0.962 Female 20 (37.0%) 18 (37.5%) Lesion location Central 33 (61.1%) 24 (50.0%) 0.259 Peripheral 21 (38.9%) 24 (50.0%) Lesion size ≥ 2 cm 49 (90.7%) 44 (91.7%) 0.869 < 2 cm 5 (9.3%) 4 (8.2%) Lesion lobe (right) Right lung 30 (55.6%) 31 (64.6%) 0.353 Left lung 24 (44.4%) 17 (35.4%) Right upper lobe 16 (29.6%) 7 (15.6%) 0.192 Right middle lobe 6 (11.1%) 8 (16.7%) Right lower lobe 8 (14.8%) 16 (33.3%) Left upper division 8 (14.8%) 6 (12.5%) Left lingual lobe 5 (9.3%) 3 (6.3%) Left lower lobe 11 (20.4%) 8 (16.7%) Positive bronchus sign 54 (100%) 48 (100%) Bronchoscope type BF-1TQ290 3 (5.6%) 6 (12.5%) 0.217 BF-Q290 48 (88.9%) 37 (77.1%) BF-P290 3 (5.6%) 5 (10.4%) IVG 9 (16.7%) 9 (18.8%) 0.783 Table 2 Final diagnoses Final Diagnosis Guide Sheath (n = 54) Conventional (n = 48) P value Malignant 44 (81.5%) 38 (79.2%) 0.769 Lung cancer 38 (86.4%) 35 (92.1%) 0.402 Adenocarcinoma 30 (78.9%) 26 (74.3%) Squamous cell carcinoma 4 (10.5%) 5 (14.3%) Small cell carcinoma 1 (2.6%) 2 (5.7%) Other lung cancer 3 (8.0%) 2 (5.7%) Metastatic carcinoma 4 (9.1%) 2 (5.3%) Mesothelioma 1 (2.3%) 1 (2.6%) Lymphoma 1 (2.3%) 0 (0%) Benign 10 (18.5%) 8 (16.7%) Mycobacterial infection 2 (20.0%) 2 (25.0%) Bacterial pneumonia 5 (50.0%) 5 (62.5%) Organizing pneumonia 2 (20.0%) 1 (12.5%) Atelectasis 1 (10.0%) 0 (0%) Lost to follow-up without a final diagnosis 0 (0%) 2 (4.2%) The procedural details and complications of each group are listed in Table 3 . For both groups, most of the lesions were concentric under rEBUS (GS vs. conventional: 81.5% vs. 81.3%, p = 0.976). The average number of biopsies was 8.9 in the GS group and 6.9 in the conventional group (p < 0.001), while the procedure time was significantly longer in the GS group (GS vs. conventional: 17.6 ± 4.7 min vs. 15.1 ± 4.5 min, p = 0.008). There was no statistical difference in the sample size between the 2 groups (GS vs. conventional: 5.5 ± 8.7 mm 3 vs. 4.6 ± 6.1 mm 3 , p = 0.551). The pathology yield rate was higher, but not statistically significantly so, in the GS group (GS vs. conventional: 75.9% vs. 68.8%, p = 0.418), but was about the same if only cancer patients were counted (GS vs. conventional: 70.5% vs. 68.4%, p = 0.812). Moreover, the brushing cytology yield rate (GS vs. conventional: 64.3% vs. 42.9%, p = 0.030) and the washing cytology yield rate (GS vs. conventional: 41.5% vs. 20.0%, p = 0.044) were both significantly higher in the GS group. Nonetheless, comparing the washing culture from the GS to the bronchial washing culture from the conventional group, the yield rate was significantly higher in the conventional group (GS vs. conventional: 0% vs. 57.1%, p = 0.017), despite the rather low patient number (accounting only for patients with a diagnosis of bacterial pneumonia and mycobacterial infection). Table 3 Bronchoscopic findings and results Guide Sheath (n = 54) Conventional (n = 48) P value rEBUS image type Concentric 44 (81.5%) 39 (81.3%) 0.976 Eccentric 10 (18.5%) 9 (18.7%) Distance from the orifice (cm, mean ± SD) 2.1 ± 1.5 2.7 ± 1.9 0.150 Procedure time (min, mean ± SD) 17.6 ± 4.7 15.1 ± 4.5 0.008 Number of biopsies 8.9 ± 2.8 6.9 ± 2.5 < 0.001 Sample size (mm 3 , mean ± SD) 5.5 ± 8.7 4.6 ± 6.1 0.551 Pathology yield rate 75.9% (41/54) 68.8% (33/48) 0.418 Cancer yield rate 70.5% (31/44) 68.4% (26/38) 0.812 Culture of biopsy tissue yield rate 50.0% (2/4) 83.3% (5/6) 0.367 Brush yield rate 64.3% (27/42) 42.9% (15/35) 0.030 Washing cytology 41.5% (17/41) 20.0% (7/35) 0.044 Washing culture 0% (0/7) 57.1% (4/7) 0.017 ≥ Grade 2 bleeding 9.3% (5/54) 20.8% (10/48) 0.049 Complication* 3.7% (2/54) 4.2% (2/48) 0.904 * Two patients in the guide sheath group had pneumothorax, while one had pneumothorax and the other one had grade 3 bleeding in the conventional group. As for complications, two patients in each group had pneumothorax after the procedure (GS vs. conventional: 3.7% vs. 4.2%, p = 0.904). The severity of post-procedure bleeding was much higher in the conventional group, as there was significantly more grade 2 and above bleeding (GS vs. conventional: 9.3% vs. 20.8%, p = 0.049). Discussion This was a prospective randomized controlled study designed to determine whether the diagnostic yield of rEBUS-TBB with a GS is better than the conventional method. We demonstrated the pathology and cytology yield were higher in the GS group, despite low number of cases in our study. In addition, we found that the microbiological culture yield of the washing fluid from the GS was much lower than the conventional washing for those with the initial diagnosis of pulmonary infection. During our enrollment period, Oki et al.( 24 ) conducted a study that demonstrated that rEBUS-TBB with a GS had a statistically higher diagnostic yield than the non-GS method. They studied 596 patients with PPLs ≤ 30 mm in diameter. The diagnostic yield was 55.3% versus 46.6% (GS vs. non-GS; p = 0.033). However, the study from Guan et al.( 25 ) suggested the non-GS method had a higher diagnostic yield. They included 569 cases with PPLs ≥ 30 mm in diameter, and the positive diagnosis rate was 74.91% vs. 76.95% (GS vs. non-GS; non-inferiority U‑test p ≤ 0.05). On stratification, Oki et al.( 24 ) suggested the GS group was better with peripheral lesions (53.4% vs. 43.8%, p = 0.032) and positive bronchus signs on CT (59.2% vs. 49.1%, p = 0.029); while in Guan’s study,( 25 ) the GS group was also better with peripheral lesions (76.30% vs. 74.59%), but worse with central lesions (72.37% vs. 81.44%). Other studies also proposed that the GS was better with peripheral, small lesions, as well as concentric lesions.( 26 – 29 ) In our study (as shown in Supplementary Table 1), the GS group tended to have better performance with peripheral lesions (80.9% vs. 66.7%), lesions < 2 cm (100% vs. 75.0%), and concentric lesions (81.8% vs. 71.8%). Meanwhile, the conventional group had a higher diagnostic yield with eccentric lesions (55.6% vs. 50.0%), which, as Ost et al. suggested, might be due to the possibility of collecting multiple biopsies from various locations with the conventional method. With peripheral small lesions, it is easier to go to the wrong bifurcations when repeating the biopsy using the conventional method, especially when bleeding occurs and the view is blocked. GS can ensure that the biopsy forceps goes into the same bifurcation, thus making the sampling more precise. It is already well-known that concentric lesions have a higher yield rate than eccentric lesions( 11 ), and since the GS can fix an identical biopsy route, it is easier to have a higher yield than with the conventional method. Our study also found that using a GS can increase the cytology yield, with both washing cytology (GS vs. conventional: 41.5% vs. 20.0%, p = 0.044) and brushing cytology (GS vs. conventional: 64.3% vs. 42.9%, p = 0.030). Izumo et al.( 10 ) also reported that brushing cytology with a GS, device washing (rinsing the biopsy forceps and cytology brush after sampling), and GS flush had a better yield rate than bronchial lavage. Even though cytology alone cannot make a definite diagnosis, it is still a very useful tool to help in making the correct diagnosis.( 30 – 32 ) In addition, we found that the microbiological culture yield of the washing fluid from the GS was much lower than that of conventional bronchial washing (GS vs. conventional: 0.0% vs. 57.1%, p = 0.044) for those with the final diagnosis of pulmonary infection. It is possible that the retaining fluid in the GS is mostly blood and therefore has low microbiology yield. To the best of our knowledge, there are no studies concerning the efficacy of microbiological culture of the retaining fluid or washing fluid from the GS. Because of this finding, we think culture of the washing fluid from the GS cannot replace the bronchial washing culture. Additional bronchial washing is recommended for the GS procedure, in order to achieve better microbiology study results. It was reported that TBB with a GS had less hemorrhage risk than conventional forceps biopsy.( 25 ) Our study confirmed this result, with the finding that there was much less moderate bleeding (grade 2 and above) in the GS group (GS vs. conventional: 9.3% vs. 20.8%, p = 0.049). Procedure time results were inconsistent in different studies, with some suggesting that procedure time was longer in the GS group,( 33 , 34 ) while others indicated it was shorter than with the conventional procedure.( 27 ) In our study, the procedure time was longer in the GS group (GS vs. conventional: 17.6 ± 4.7 min vs. 15.1 ± 4.5 min, p = 0.008). However, there was a confounding factor, in that the biopsy numbers were also greater in the GS group (GS vs. conventional: 8.9 ± 2.8 vs. 6.9 ± 2.5, p < 0. 001). The main purpose of using a GS is to solve the problem of not being able to perform TBB under real-time rEBUS guidance, due to the single working channel with the current bronchoscope. Our study demonstrated that the GS can increase the accuracy of TBB. However, fluoroscopy can serve the same purpose and increase the accuracy and diagnostic yield.( 35 , 36 ) While, as previously described, GS had better performance in small lesions, Ito et al.( 17 ) suggested that when under fluoroscope-guidance, the conventional method could have even better performance. There are some limitations in our study. The most significant one is the low case number (102 patients), which may lead to lower statistical power. Moreover, we found that the diagnostic yield was higher in the GS group, but we allowed an additional number of biopsies, and indeed the GS group had a higher biopsy number. This might be a confounding factor relative to the results. Finally, this was a study from a single center that might not be representative of all institutes. In conclusion, rEBUS TBB with a GS has a trend of better pathology yield rate than conventional biopsy in peripheral lesions, small lesions, and concentric lesions. It also has a better cytology yield and a lower risk of bleeding; however, the washing culture yield from the GS was lower than that from conventional bronchial washing. Further studies with larger number of cases are warranted. Abbreviations rEBUS radial probe endobronchial ultrasound TBB transbronchial biopsy GS guide sheath PPL peripheral lung lesion CT computed tomography ROSE rapid on-site cytological evaluation Declarations Ethics approval and consent to participate: The study was approved by the Institutional Review Board of NTUH (201904072RINC) Consent for publication: Not applicable Availability of data and materials: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests: There are no conflicts of interest for all authors. Funding: There was no funding to declare for this study. Authors' contributions: HCC: study design, data acquisition and analysis, data interpretation, drafting the work, approved the final version to be published, and agreed to be accountable for all aspects of the work YWK: study design, data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work CKL: study design, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work LCC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work YYC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work CYY: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work JYC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work CLH: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work THT: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work CCH: study design, data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work JYS: data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work CJY: data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work Acknowledgement: Special thanks to Hsu-Chieh Wang, Chin-Hao Chang, and Shang-Chieh Tsai for helping the case enrollment and other administration work. 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Tsai TH, Yang CY, Ho CC, Liao WY, Jan IS, Chen KY, et al. Multi-gene analyses from waste brushing specimens for patients with peripheral lung cancer receiving EBUS-assisted bronchoscopy. Lung Cancer. 2013;82(3):420–5. Mak VH, Johnston ID, Hetzel MR, Grubb C. Value of washings and brushings at fibreoptic bronchoscopy in the diagnosis of lung cancer. Thorax. 1990;45(5):373–6. Huang CT, Chang LY, Chen CY, Ruan SY, Lin CK, Tsai YJ et al. Endobronchial ultrasound-guided transbronchial biopsy with or without a guide sheath for peripheral pulmonary malignancy. ERJ Open Res. 2021;7(3). Oki M, Saka H, Kitagawa C, Kogure Y, Murata N, Adachi T, et al. Randomized study of endobronchial ultrasound-guided transbronchial biopsy: thin bronchoscopic method versus guide sheath method. J Thorac Oncol. 2012;7(3):535–41. Lin CK, Fan HJ, Yao ZH, Lin YT, Wen YF, Wu SG et al. Cone-Beam Computed Tomography-Derived Augmented Fluoroscopy Improves the Diagnostic Yield of Endobronchial Ultrasound-Guided Transbronchial Biopsy for Peripheral Pulmonary Lesions. Diagnostics (Basel). 2021;12(1). Yu KL, Yang SM, Ko HJ, Tsai HY, Ko JC, Lin CK, et al. Efficacy and Safety of Cone-Beam Computed Tomography-Derived Augmented Fluoroscopy Combined with Endobronchial Ultrasound in Peripheral Pulmonary Lesions. Respiration. 2021;100(6):538–46. Additional Declarations No competing interests reported. Supplementary Files SupplementaryTable1.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3824206","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":264837348,"identity":"a907792e-1766-43ef-996b-4ad23fd98dc1","order_by":0,"name":"Hao-Chun Chang","email":"","orcid":"","institution":"National Taiwan University Hsinchu Branch","correspondingAuthor":false,"prefix":"","firstName":"Hao-Chun","middleName":"","lastName":"Chang","suffix":""},{"id":264837349,"identity":"449ac0a3-23bf-47d3-ac97-260d3f73eb40","order_by":1,"name":"Yao-Wen Kuo","email":"","orcid":"","institution":"National Taiwan University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yao-Wen","middleName":"","lastName":"Kuo","suffix":""},{"id":264837350,"identity":"f9a8c243-bbf8-47cc-a077-265a21941360","order_by":2,"name":"Ching-Kai Lin","email":"","orcid":"","institution":"National Taiwan University Cancer Center","correspondingAuthor":false,"prefix":"","firstName":"Ching-Kai","middleName":"","lastName":"Lin","suffix":""},{"id":264837351,"identity":"6ca737c9-fa33-40d1-b66a-bae266d95317","order_by":3,"name":"Lih-Chyun Chang","email":"","orcid":"","institution":"National Taiwan University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Lih-Chyun","middleName":"","lastName":"Chang","suffix":""},{"id":264837352,"identity":"96c2c435-fd76-4b56-9dfd-e822c2690d95","order_by":4,"name":"You-Yi Chen","email":"","orcid":"","institution":"National Taiwan University Yunlin Branch","correspondingAuthor":false,"prefix":"","firstName":"You-Yi","middleName":"","lastName":"Chen","suffix":""},{"id":264837353,"identity":"45f852cb-5af2-44f7-8f62-76fd988295d4","order_by":5,"name":"Ching-Yao Yang","email":"","orcid":"","institution":"National Taiwan University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ching-Yao","middleName":"","lastName":"Yang","suffix":""},{"id":264837354,"identity":"7bcdc2c2-3633-4c46-9006-4ee3a7fff783","order_by":6,"name":"Jun-Yen Chien","email":"","orcid":"","institution":"National Taiwan University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jun-Yen","middleName":"","lastName":"Chien","suffix":""},{"id":264837355,"identity":"f4f65364-c8fe-4865-930e-a8b44d421e43","order_by":7,"name":"Chia-Lin Hsu","email":"","orcid":"","institution":"National Taiwan University 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14:29:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3824206/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3824206/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53608770,"identity":"b2d061fc-9fa4-4012-82d2-64bbb1897589","added_by":"auto","created_at":"2024-03-28 04:35:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":329823,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3824206/v1/393d66b4-da56-4373-9f78-06ce176f2c3f.pdf"},{"id":49118109,"identity":"6ca850f7-e0a8-419d-9be7-e0cc573653e4","added_by":"auto","created_at":"2024-01-03 11:54:50","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":15279,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTable1.docx","url":"https://assets-eu.researchsquare.com/files/rs-3824206/v1/e278a0fc70d153941be8106c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Assessment of using radial probe endobronchial ultrasound with a guide sheath to increase the yield rate of transbronchial biopsy: A prospective randomized trial","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBronchoscopy is a commonly used diagnostic tool for peripheral pulmonary lesions (PPLs), but its diagnostic yield varies widely among studies.(\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) To improve the diagnostic yield, the use of radial probe endobronchial ultrasound (rEBUS) during bronchoscopic transbronchial biopsy (TBB) has been recommended in The American College of Chest Physicians Guidelines for Diagnosis and Management of Lung Cancer (3rd edition).(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) rEBUS helps localize the lesions, and the bronchi leading to them; however, its major limitation is that real-time views are not obtained. This means that TBB and rEBUS scanning cannot be performed simultaneously, making it difficult to confirm that the biopsy instrument has been advanced through the bronchial route taken by the rEBUS probe to the target lesion.(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eTo overcome this limitation, Kurimoto et al.(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) introduced the concept of rEBUS-guided TBB with a guide sheath (GS), which aimed to enhance the diagnostic accuracy of PPLs. This method involves inserting the ultrasound probe into the GS, extending it into the bronchoscopy working channel, reaching the lesions, removing the ultrasound probe while keeping the GS in place, and then inserting the biopsy forceps through the GS to obtain appropriate tissues. This has been found to be useful by many investigators.(\u003cspan additionalcitationids=\"CR8 CR9 CR10 CR11 CR12 CR13 CR14 CR15\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) However, the use of a GS imposes a size limitation on the sampling instruments, while rEBUS-TBB without a GS (the conventional method) allows the use of larger biopsy forceps that may improve the diagnostic yield.(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) Furthermore, the conventional method, which involves collecting multiple biopsies from various locations, has been hypothesized to increase the chance of obtaining at least one diagnostic sample compared to using the fixed location of the GS method.(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eThe GS method has some disadvantages, including technical complexity, possible displacement by coughing or deep respiration, and instrumental issues like kinking or bending of the GS and resistance during the advancing of biopsy instruments.(\u003cspan additionalcitationids=\"CR20 CR21 CR22\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e) The diagnostic yield of rEBUS-TBB with and without a GS has been the subject of only a few small comparative studies, and the use of a GS during rEBUS-TBB remains controversial. Therefore, we conducted this prospective randomized controlled study to compare the diagnostic yield of rEBUS-TBB with a GS to the conventional method. In addition, we also compared the microbiological culture results of two different specimen collection methods for those with the final diagnosis of pneumonia and mycobacterial infection.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy patients\u003c/h2\u003e \u003cp\u003eThis study was conducted at National Taiwan University Hospital (NTUH), a university teaching hospital with 2500 beds in northern Taiwan. From November 2019 to March 2023, patients with PPLs on a computed tomography (CT) scan were recruited and randomly assigned to rEBUS-TBB with a GS (GS group) or without a GS (conventional group). Randomization was stratified by lesion size (greatest diameter\u0026thinsp;\u0026lt;\u0026thinsp;20 or \u0026ge;\u0026thinsp;20 mm on CT scans), distance from the hilum (in the peripheral two-thirds or central one-third of the CT lung field), and rEBUS image type (concentric or eccentric). Allocations were performed electronically at a 1:1 ratio. The inclusion criteria were adult patients (age\u0026thinsp;\u0026ge;\u0026thinsp;20 years old) with PPLs requiring diagnosis that could be found by rEBUS. The exclusion criteria were B1 (RB1 \u0026amp; LB1/2) and B6 lesions, which were difficult for the GS to approach. The study was approved by the Institutional Review Board of NTUH (201904072RINC) and was registered at Clinicaltrials.gov (NCT04056273). All included participants provided written informed consent.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eBronchoscopic procedure\u003c/h2\u003e \u003cp\u003eMost of the patients underwent bronchoscopic procedures under local anesthesia with clear consciousness. Some patients (about 17%) were given intravenous general anesthesia due to personal preference, although intravenous general anesthesia for bronchoscopy was not covered by Taiwan\u0026rsquo;s national health insurance program. The standard 4.8-mm bronchoscope, with a 2.0-mm working channel (BF-Q290; Olympus), was used for the majority of patients (about 80%), while therapeutic scopes, with a 5.9-mm width and 3.0-mm working channels (BF-1TQ290; Olympus), and thin scopes, with a 4.2-mm width and 2.0-mm working channels (BF-P290; Olympus), were the other options.\u003c/p\u003e \u003cp\u003eAfter the bronchoscope reached the segment of the lesion, localized by CT scan, a 1.4-mm diameter rEBUS probe (UM-S20-17S; Olympus) was advanced through the working channel toward the lesion. When the target lesion was found by rEBUS, the distance from the segment orifice was measured. For the GS group, the rEBUS probe was reinserted again with a GS (K201 or K203; Olympus; depending on the working channel size of the scope used). GS was then deployed at the target lesion, and forceps biopsy as well as cytology brushing, from the GS kit, were done within the GS. After sampling, the GS was retrieved from the working channel, and 25 ml saline was used to irrigate the GS for the bronchial washing sample.\u003c/p\u003e \u003cp\u003eAs for the conventional group, a 2.0-mm biopsy forceps (FB-231D; Olympus) and a 2.0-mm cytology brush (BC-202D-2010; Olympus) were used, and bronchial washing was also performed after sampling. Biopsy was taken at least six times for each group. Microbiological cultures of biopsy tissue were also performed for those whom infectious disease was suspected. Rapid on-site cytological evaluation (ROSE) was not performed for either group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eEvaluation parameters\u003c/h2\u003e \u003cp\u003eThe primary end-point was the histopathological diagnostic yield of the allocated group. The secondary end-points included procedure time, frequency of complications, bronchial brushing and washing cytology yield, microbiological culture yield, and diagnostic yield stratified by malignancy or not, the lesion\u0026rsquo;s location, lesion size, and rEBUS image pattern. A positive diagnostic yield was considered to be obtained when the pathology report showed malignant or benign neoplasms, granulomatous inflammation, organizing pneumonia, and fungus or acid-fast positive microorganisms. The non-diagnostic yield included benign lung tissue, non-specific fibrosis, and chronic inflammation. These patients were followed up for at least six months, until the final diagnoses were established, based on pathological evidence, microbiological culture results, and radiological images. If pneumonia was the clinical diagnosis and the lesion did resolve completely during follow-up, inflammation from the initial pathology report would also be considered as a positive diagnosis.\u003c/p\u003e \u003cp\u003eAs to the microbiological study, the culture results of the specimen from the GS irrigation were compared with the bronchial washing fluid in the conventional group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe Pearson Chi-squared test was used for categorical variables comparison, while Fisher's exact mid-P test was used when necessary. Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), and were compared using Student\u0026rsquo;s t-test. P values less than 0.05 were considered statistically significant. All statistical analyses were conducted using SAS version 9.4 (SAS Institute, Cary, NC, USA).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eDuring the study period, 102 of the 1309 patients that underwent rEBUS-TBB were enrolled in the study. The baseline characteristics of the patients, their lesions, and their bronchoscopic findings are listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. All 102 patients had a positive CT bronchus sign. More than half of the patients in the GS group (61.1%) and half in the conventional group (50.0%) had centrally located lesions (p\u0026thinsp;=\u0026thinsp;0.259). The majority of the lesions were more than 2 centimeters in diameter (GS vs. conventional: 90.7% vs. 91.7%, p\u0026thinsp;=\u0026thinsp;0.869). Only a few patients underwent the procedure with BF-1TQ290 (with a 3.0 mm working channel) (GS vs. conventional: 5.6% vs. 12.5%, p\u0026thinsp;=\u0026thinsp;0.217). The final diagnoses of the patients are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The majority of the diagnoses were malignancy (GS vs. conventional: 81.5% vs. 79.2%, p\u0026thinsp;=\u0026thinsp;0.769), especially lung cancer (GS vs. conventional: 86.4% vs. 92.1%, p\u0026thinsp;=\u0026thinsp;0.402).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristics of the patients and their lesions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGuide Sheath (n\u0026thinsp;=\u0026thinsp;54)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConventional\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65.8\u0026thinsp;\u0026plusmn;\u0026thinsp;13.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.6\u0026thinsp;\u0026plusmn;\u0026thinsp;10.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.769\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (Male)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34 (63.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 (62.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.962\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (37.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (37.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLesion location\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCentral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33 (61.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.259\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeripheral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21 (38.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLesion size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge; 2 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49 (90.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44 (91.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.869\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt; 2 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (9.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (8.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLesion lobe (right)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight lung\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 (55.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31 (64.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.353\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft lung\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (44.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17 (35.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight upper lobe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (29.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (15.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003e0.192\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight middle lobe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (11.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight lower lobe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (14.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (33.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft upper division\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (14.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft lingual lobe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (9.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (6.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft lower lobe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (20.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePositive bronchus sign\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e54 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBronchoscope type\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBF-1TQ290\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (5.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.217\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBF-Q290\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48 (88.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (77.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBF-P290\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (5.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (10.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 (18.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.783\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFinal diagnoses\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFinal Diagnosis\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGuide Sheath (n\u0026thinsp;=\u0026thinsp;54)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConventional\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44 (81.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38 (79.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.769\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLung cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38 (86.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35 (92.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.402\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 (78.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26 (74.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSquamous cell carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (10.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmall cell carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther lung cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (8.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetastatic carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (9.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (5.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMesothelioma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (2.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLymphoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBenign\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (18.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMycobacterial infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (25.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBacterial pneumonia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (50.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (62.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOrganizing pneumonia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtelectasis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLost to follow-up\u003c/p\u003e \u003cp\u003ewithout a final diagnosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe procedural details and complications of each group are listed in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. For both groups, most of the lesions were concentric under rEBUS (GS vs. conventional: 81.5% vs. 81.3%, p\u0026thinsp;=\u0026thinsp;0.976). The average number of biopsies was 8.9 in the GS group and 6.9 in the conventional group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), while the procedure time was significantly longer in the GS group (GS vs. conventional: 17.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 min vs. 15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5 min, p\u0026thinsp;=\u0026thinsp;0.008). There was no statistical difference in the sample size between the 2 groups (GS vs. conventional: 5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;8.7 mm\u003csup\u003e3\u003c/sup\u003e vs. 4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1 mm\u003csup\u003e3\u003c/sup\u003e, p\u0026thinsp;=\u0026thinsp;0.551). The pathology yield rate was higher, but not statistically significantly so, in the GS group (GS vs. conventional: 75.9% vs. 68.8%, p\u0026thinsp;=\u0026thinsp;0.418), but was about the same if only cancer patients were counted (GS vs. conventional: 70.5% vs. 68.4%, p\u0026thinsp;=\u0026thinsp;0.812). Moreover, the brushing cytology yield rate (GS vs. conventional: 64.3% vs. 42.9%, p\u0026thinsp;=\u0026thinsp;0.030) and the washing cytology yield rate (GS vs. conventional: 41.5% vs. 20.0%, p\u0026thinsp;=\u0026thinsp;0.044) were both significantly higher in the GS group. Nonetheless, comparing the washing culture from the GS to the bronchial washing culture from the conventional group, the yield rate was significantly higher in the conventional group (GS vs. conventional: 0% vs. 57.1%, p\u0026thinsp;=\u0026thinsp;0.017), despite the rather low patient number (accounting only for patients with a diagnosis of bacterial pneumonia and mycobacterial infection).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBronchoscopic findings and results\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGuide Sheath (n\u0026thinsp;=\u0026thinsp;54)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eConventional\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erEBUS image type\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eConcentric\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44 (81.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e39 (81.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.976\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEccentric\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (18.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9 (18.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDistance from the orifice (cm, mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.150\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedure time\u003c/p\u003e \u003cp\u003e(min, mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of biopsies\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample size\u003c/p\u003e \u003cp\u003e(mm\u003csup\u003e3\u003c/sup\u003e, mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;8.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.551\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePathology yield rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e75.9% (41/54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e68.8% (33/48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.418\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCancer yield rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70.5% (31/44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e68.4% (26/38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.812\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCulture of biopsy tissue yield rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.0% (2/4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e83.3% (5/6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.367\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBrush yield rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.3% (27/42)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e42.9% (15/35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWashing cytology\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41.5% (17/41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.0% (7/35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.044\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWashing culture\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0% (0/7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e57.1% (4/7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge; Grade 2 bleeding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.3% (5/54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.8% (10/48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.049\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplication*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.7% (2/54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.2% (2/48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.904\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e* Two patients in the guide sheath group had pneumothorax, while one had pneumothorax and the other one had grade 3 bleeding in the conventional group.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAs for complications, two patients in each group had pneumothorax after the procedure (GS vs. conventional: 3.7% vs. 4.2%, p\u0026thinsp;=\u0026thinsp;0.904). The severity of post-procedure bleeding was much higher in the conventional group, as there was significantly more grade 2 and above bleeding (GS vs. conventional: 9.3% vs. 20.8%, p\u0026thinsp;=\u0026thinsp;0.049).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis was a prospective randomized controlled study designed to determine whether the diagnostic yield of rEBUS-TBB with a GS is better than the conventional method. We demonstrated the pathology and cytology yield were higher in the GS group, despite low number of cases in our study. In addition, we found that the microbiological culture yield of the washing fluid from the GS was much lower than the conventional washing for those with the initial diagnosis of pulmonary infection.\u003c/p\u003e \u003cp\u003eDuring our enrollment period, Oki et al.(\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e) conducted a study that demonstrated that rEBUS-TBB with a GS had a statistically higher diagnostic yield than the non-GS method. They studied 596 patients with PPLs\u0026thinsp;\u0026le;\u0026thinsp;30 mm in diameter. The diagnostic yield was 55.3% versus 46.6% (GS vs. non-GS; p\u0026thinsp;=\u0026thinsp;0.033). However, the study from Guan et al.(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) suggested the non-GS method had a higher diagnostic yield. They included 569 cases with PPLs\u0026thinsp;\u0026ge;\u0026thinsp;30 mm in diameter, and the positive diagnosis rate was 74.91% vs. 76.95% (GS vs. non-GS; non-inferiority U‑test p\u0026thinsp;\u0026le;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003eOn stratification, Oki et al.(\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e) suggested the GS group was better with peripheral lesions (53.4% vs. 43.8%, p\u0026thinsp;=\u0026thinsp;0.032) and positive bronchus signs on CT (59.2% vs. 49.1%, p\u0026thinsp;=\u0026thinsp;0.029); while in Guan\u0026rsquo;s study,(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) the GS group was also better with peripheral lesions (76.30% vs. 74.59%), but worse with central lesions (72.37% vs. 81.44%). Other studies also proposed that the GS was better with peripheral, small lesions, as well as concentric lesions.(\u003cspan additionalcitationids=\"CR27 CR28\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e) In our study (as shown in Supplementary Table\u0026nbsp;1), the GS group tended to have better performance with peripheral lesions (80.9% vs. 66.7%), lesions\u0026thinsp;\u0026lt;\u0026thinsp;2 cm (100% vs. 75.0%), and concentric lesions (81.8% vs. 71.8%). Meanwhile, the conventional group had a higher diagnostic yield with eccentric lesions (55.6% vs. 50.0%), which, as Ost et al. suggested, might be due to the possibility of collecting multiple biopsies from various locations with the conventional method. With peripheral small lesions, it is easier to go to the wrong bifurcations when repeating the biopsy using the conventional method, especially when bleeding occurs and the view is blocked. GS can ensure that the biopsy forceps goes into the same bifurcation, thus making the sampling more precise. It is already well-known that concentric lesions have a higher yield rate than eccentric lesions(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), and since the GS can fix an identical biopsy route, it is easier to have a higher yield than with the conventional method.\u003c/p\u003e \u003cp\u003eOur study also found that using a GS can increase the cytology yield, with both washing cytology (GS vs. conventional: 41.5% vs. 20.0%, p\u0026thinsp;=\u0026thinsp;0.044) and brushing cytology (GS vs. conventional: 64.3% vs. 42.9%, p\u0026thinsp;=\u0026thinsp;0.030). Izumo et al.(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e) also reported that brushing cytology with a GS, device washing (rinsing the biopsy forceps and cytology brush after sampling), and GS flush had a better yield rate than bronchial lavage. Even though cytology alone cannot make a definite diagnosis, it is still a very useful tool to help in making the correct diagnosis.(\u003cspan additionalcitationids=\"CR31\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eIn addition, we found that the microbiological culture yield of the washing fluid from the GS was much lower than that of conventional bronchial washing (GS vs. conventional: 0.0% vs. 57.1%, p\u0026thinsp;=\u0026thinsp;0.044) for those with the final diagnosis of pulmonary infection. It is possible that the retaining fluid in the GS is mostly blood and therefore has low microbiology yield. To the best of our knowledge, there are no studies concerning the efficacy of microbiological culture of the retaining fluid or washing fluid from the GS. Because of this finding, we think culture of the washing fluid from the GS cannot replace the bronchial washing culture. Additional bronchial washing is recommended for the GS procedure, in order to achieve better microbiology study results.\u003c/p\u003e \u003cp\u003eIt was reported that TBB with a GS had less hemorrhage risk than conventional forceps biopsy.(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) Our study confirmed this result, with the finding that there was much less moderate bleeding (grade 2 and above) in the GS group (GS vs. conventional: 9.3% vs. 20.8%, p\u0026thinsp;=\u0026thinsp;0.049). Procedure time results were inconsistent in different studies, with some suggesting that procedure time was longer in the GS group,(\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e) while others indicated it was shorter than with the conventional procedure.(\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e) In our study, the procedure time was longer in the GS group (GS vs. conventional: 17.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 min vs. 15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5 min, p\u0026thinsp;=\u0026thinsp;0.008). However, there was a confounding factor, in that the biopsy numbers were also greater in the GS group (GS vs. conventional: 8.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8 vs. 6.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5, p\u0026thinsp;\u0026lt;\u0026thinsp;0. 001).\u003c/p\u003e \u003cp\u003eThe main purpose of using a GS is to solve the problem of not being able to perform TBB under real-time rEBUS guidance, due to the single working channel with the current bronchoscope. Our study demonstrated that the GS can increase the accuracy of TBB. However, fluoroscopy can serve the same purpose and increase the accuracy and diagnostic yield.(\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e) While, as previously described, GS had better performance in small lesions, Ito et al.(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) suggested that when under fluoroscope-guidance, the conventional method could have even better performance.\u003c/p\u003e \u003cp\u003eThere are some limitations in our study. The most significant one is the low case number (102 patients), which may lead to lower statistical power. Moreover, we found that the diagnostic yield was higher in the GS group, but we allowed an additional number of biopsies, and indeed the GS group had a higher biopsy number. This might be a confounding factor relative to the results. Finally, this was a study from a single center that might not be representative of all institutes.\u003c/p\u003e \u003cp\u003eIn conclusion, rEBUS TBB with a GS has a trend of better pathology yield rate than conventional biopsy in peripheral lesions, small lesions, and concentric lesions. It also has a better cytology yield and a lower risk of bleeding; however, the washing culture yield from the GS was lower than that from conventional bronchial washing. Further studies with larger number of cases are warranted.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003erEBUS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eradial probe endobronchial ultrasound\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTBB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etransbronchial biopsy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eguide sheath\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePPL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eperipheral lung lesion\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecomputed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eROSE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003erapid on-site cytological evaluation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e The study was approved by the Institutional Review Board of NTUH (201904072RINC)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThere are no conflicts of interest for all authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThere was no funding to declare for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHCC: study design, data acquisition and analysis, data interpretation, drafting the work, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eYWK: study design, data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eCKL: study design, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eLCC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eYYC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eCYY: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eJYC: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eCLH: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eTHT: data acquisition, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eCCH: study design, data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eJYS: data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003eCJY: data interpretation, critical work review, approved the final version to be published, and agreed to be accountable for all aspects of the work\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement:\u0026nbsp;\u003c/strong\u003eSpecial thanks to Hsu-Chieh Wang, Chin-Hao Chang, and Shang-Chieh Tsai for helping the case enrollment and other administration work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eChechani V. 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Respiration. 2021;100(6):538\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"radial probe endobronchial ultrasound, transbronchial biopsy, guide sheath, diagnostic yield, cytology","lastPublishedDoi":"10.21203/rs.3.rs-3824206/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3824206/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eRadial probe endobronchial ultrasound (rEBUS)-guided transbronchial biopsy (TBB) with a guide sheath (GS) is widely used to diagnose peripheral lung lesions (PPLs), but there is no consensus on whether it increases the diagnostic yield. We conducted this prospective study to compare the diagnostic yield of the GS method to the conventional method without a GS.\u003c/p\u003e\u003ch2\u003eMaterial and methods\u003c/h2\u003e \u003cp\u003eFrom November 2019 to March 2023, patients with PPLs were recruited and randomly assigned to rEBUS-TBB with a GS (GS group) or without a GS (conventional group). The histopathology, cytology, and microbiology yield rates, as well as procedure time and post-procedure adverse events of the two groups were compared.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 102 patients were enrolled (54 in the GS group and 48 in the conventional group). The GS group exhibited a trend of increased pathology yield (75.9% vs. 68.8%, p\u0026thinsp;=\u0026thinsp;0.418), while the yield rates of brushing cytology (64.3% vs. 42.9%, p\u0026thinsp;=\u0026thinsp;0.030) and washing cytology (41.5% vs. 20.0%, p\u0026thinsp;=\u0026thinsp;0.0443) were higher in the GS group. Meanwhile, the yield from GS washing culture was lower than the bronchial washing culture yield (0% vs. 57.1%, p\u0026thinsp;=\u0026thinsp;0.017). The bleeding risk was also lower in the GS group (9.3% vs. 20.8%, p\u0026thinsp;=\u0026thinsp;0.049), but the procedure time was longer in the GS group (17.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 min vs. 15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5 min, p\u0026thinsp;=\u0026thinsp;0.008).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003erEBUS TBB with a GS can increase the diagnostic yield of PPLs and decrease the risk of bleeding, while additional bronchial washing should be utilized to increase the microbiology yield.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eThe study was registered at Clinicaltrials.gov (NCT04056273).\u003c/p\u003e","manuscriptTitle":"Assessment of using radial probe endobronchial ultrasound with a guide sheath to increase the yield rate of transbronchial biopsy: A prospective randomized trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-03 11:54:45","doi":"10.21203/rs.3.rs-3824206/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2fa4ec8d-6122-479e-ab8c-8cf6a3c0dfcc","owner":[],"postedDate":"January 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-03-28T04:27:20+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-03 11:54:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3824206","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3824206","identity":"rs-3824206","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}