Bronchial branch tracing navigation in ultrathin bronchoscopy-guided radial endobronchial ultrasound for peripheral pulmonary nodule.

BACKGROUND: Most malignant peripheral pulmonary lesions (PPLs) are situated in the peripheral region of the lung. Although the ultrathin bronchoscope (UTB) can access these areas, a robust navigation system is essential for precise localisation of these small peripheral PPLs. Since many UTB procedures rely on automated virtual bronchoscopic navigation (VBN), this study aims to determine the accuracy and diagnostic yield of the manual bronchial branch tracing (BBT) navigation in UTB-guided radial endobronchial ultrasound (rEBUS) procedures. METHODS: Single-centre retrospective study of UTB-rEBUS patients with PPLs smaller than 3 cm over a two year period. RESULTS: Our cohort consisted of 47 patients with a mean age of 61.6 (SD 9.53) years and a mean target size of 1.91 (SD 0.53) cm. Among these lesions, 46.8% were located in the 6th airway generation, and 78.7% exhibited a direct bronchus sign. Navigation success using BBT was 91.5% based on positive rEBUS identification. The index diagnostic yield was 82.9%, increasing to 91.5% at 12 months of follow-up. Malignant lesions accounted for 65.1% of cases, while 34.9% were non-malignant. The presence of a direct bronchus sign was the sole factor associated with higher navigation success and diagnostic yield. Cryobiopsy outperformed forceps biopsy in non-concentric rEBUS lesions (90.9% vs. 50.0%, p < 0.05), but not in concentric orientated lesions. One pneumothorax occurred in our cohort. CONCLUSIONS: BBT as an exclusive navigation method for small PPLs in UTB-rEBUS procedures has proved to be safe and feasible. Combination of UTB with cryobiopsy remains efficient for eccentric and adjacently oriented rEBUS lesions.

Feasibility of Cryobiopsy Specimen Retrieval Through Standard Guide Sheath for Peripheral Pulmonary Lesions Without Bronchoscope Removal.

BACKGROUND: Transbronchial cryobiopsy is a promising technique for biopsy of peripheral pulmonary lesions (PPL). However, cryobiopsy specimen retrieval can pose problems due to the risk of bleeding during the blind period when the bronchoscope and cryoprobe are removed en bloc. Artificial airways and prophylactic balloon placement are risk-reducing measures, but the latter is challenging in upper lobe PPL. Specimen retrieval through standard guide sheath (GS) system without the need for bronchoscope removal may now be feasible with the ultrathin cryoprobe. METHODS: Retrospective review of radial endobronchial ultrasound (rEBUS)-guided transbronchial cryobiopsy for PPL cases in which cryobiopsy specimen was retrieved through the GS over a 6-month period. RESULTS: Twenty patients were included with an overall median age of 66.50 (IQR: 53.0 to 76.7). The median procedural time was 30 (IQR: 25.0 to 33.7) minutes. Median target size was 3.20 (IQR: 2.17 to 4.84) cm with 85% of lesions demonstrated "within" rEBUS orientation. Overall technical feasibility was 85% with median cryoactivation of 4.0 (IQR: 3.0 to 4.0) seconds. No specimen was retrieved in 3 patients. The diagnostic yield for forceps and cryobiopsy was 70% and 60%, respectively, and the combined diagnostic yield was 85% (P<0.01 vs. forceps biopsy). Median aggregate size for forceps and cryobiopsy was 8.0 (IQR: 5.3 to 10.0) and 4.5 (IQR: 2.3 to 7.0) mm respectively (P<0.01). No pneumothorax was reported and mild self-limiting bleeding was encountered in 30% of cases. CONCLUSION: Retrieval of cryoprobe through standard GS appears to be a safe and feasible method that can simplify the transbronchial cryobiopsy procedure and complement forceps biopsy in specific cases.

An explorative analysis on the optimal cryo-passes and freezing time of the ultrathin cryoprobe in endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy.

EBUS-guided transbronchial mediastinal cryobiopsy (TBMC) has emerged as a promising biopsy tool for diagnosing hilar and mediastinal pathologies. However, several fundamental technical aspects of TBMC remain unexplored. This study aims to determine the optimal number of cryo-passes and freezing time of the ultrathin cryoprobe in EBUS-TBMC concerning specimen size and procedural diagnostic yield. We conducted a retrospective chart review of patients with mediastinal and hilar lesions who underwent EBUS-TBMC between January 2021 and April 2023 across three hospitals in Malaysia. A total of 129 EBUS-TBMC procedures were successfully completed, achieving an overall diagnostic yield of 88.4%. Conclusive TBMC procedures were associated with larger specimen sizes (7.0 vs. 5.0 mm, p < 0.01). Specimen size demonstrated a positive correlation with diagnostic yield (p < 0.01), plateauing at specimen size of 4.1-6.0 mm. A significant positive correlation was also observed between the number of cryo-passes and both specimen size (p < 0.01) and diagnostic yield (p < 0.05). Diagnostic yield plateaued after 2-3 cryo-passes. In contrast, longer freezing times trended towards smaller specimens and lower diagnostic yield, though not reaching statistical significance. The highest diagnostic yield was recorded at the 3.1-4.0 s freezing time. The safety profile of TBMC remains favourable, with one case (0.8%) of pneumothorax and nine cases (7%) of self-limiting bleeding. In our cohort, TBMC performance with 2-3 cryo-passes and a 3.1-4.0 s freezing time to achieve a total aggregate specimen size of 4.1-6.0 mm appeared optimal. Further prospective studies are needed to validate these findings.

Identification of phenomic data in the pathogenesis of cancers of the gastrointestinal (GI) tract in the UK biobank.

Gastrointestinal (GI) cancers account for a significant incidence and mortality rates of cancers globally. Utilization of a phenomic data approach allows researchers to reveal the mechanisms and molecular pathogenesis of these conditions. We aimed to investigate the association between the phenomic features and GI cancers in a large cohort study. We included 502,369 subjects aged 37-73 years in the UK Biobank recruited since 2006, followed until the date of the first cancer diagnosis, date of death, or the end of follow-up on December 31st, 2016, whichever occurred first. Socio-demographic factors, blood chemistry, anthropometric measurements and lifestyle factors of participants collected at baseline assessment were analysed. Unvariable and multivariable logistic regression were conducted to determine the significant risk factors for the outcomes of interest, based on the odds ratio (OR) and 95% confidence intervals (CI). The analysis included a total of 441,141 participants, of which 7952 (1.8%) were incident GI cancer cases and 433,189 were healthy controls. A marker, cystatin C was associated with total and each gastrointestinal cancer (adjusted OR 2.43; 95% CI 2.23-2.64). In this cohort, compared to Asians, the Whites appeared to have a higher risk of developing gastrointestinal cancers. Several other factors were associated with distinct GI cancers. Cystatin C and race appear to be important features in GI cancers, suggesting some overlap in the molecular pathogenesis of GI cancers. Given the small proportion of Asians within the UK Biobank, the association between race and GI cancers requires further confirmation.

Performance of radial endobronchial ultrasound for peripheral pulmonary lesions without automation technology in tuberculous endemic region: real-world experience in a single institution over 6 years.

Background: Peripheral pulmonary lesions (PPLs) in tuberculous endemic regions present a unique diagnostic challenge, as tuberculous PPL can mimic malignancy and potentially delay diagnosis for both conditions without a confirmatory investigation. While bronchoscopic biopsy using radial endobronchial ultrasound (rEBUS) guidance is becoming more common among pulmonologists, it is often performed with additional automation technology such as virtual bronchoscopic and electromagnetic navigation. This study aimed to evaluate the performance of rEBUS without such automation technology over a 6-year period in our institution. Methods: Retrospective chart review of all adult patients undergoing rEBUS-guided transbronchial biopsy for PPL in our institution over 6 years duration (October 2016 to December 2022). Results: A total of 551 PPLs were included with median target lesion size of 2.70 (interquartile range, 2.10-3.70) cm. In total, 84.2% of lesion demonstrated direct bronchus sign with 46.3% demonstrating concentric rEBUS orientation. The overall diagnostic yield was 78.8% [95% confidence interval (CI): 75.1-82.1%], with 1.1% rate of pneumothorax. Among the conclusive cases, 62.7% were malignant while 37.3% were tuberculous. Bronchus sign [adjusted odds ratio (adj. OR): 2.268] and concentric rEBUS orientation (adj. OR: 3.426) are independent predictors for conclusive procedure. The sensitivity of rEBUS for malignant and tuberculous disease was 85.27% (95% CI: 80.89-88.97%) and 71.77% (95% CI: 62.99-79.49%) respectively. A significant improving trend of diagnostic yield over time with reduction of median PPL size was observed with introduction of cryobiopsy and thin bronchoscopy into rEBUS service. Conclusions: rEBUS without automation technology remains relevant and useful in this era. rEBUS provides a rapid and safe diagnosis of PPL which may translate into better patient care.

Development and validation of Join Clinical Trial Questionnaire (JoinCT).

AIM: Participant recruitment has always been a major challenge in clinical trials. This study aimed to develop and validate the Join Clinical Trial Questionnaire (JoinCT), exploring the willingness to join a clinical trial and associated factors in patients. METHODS: This questionnaire development study involved four phases: (i) exploring and understanding the subject matter, (ii) questionnaire development, (iii) content validity testing, and lastly, (iv) field-testing of the questionnaire. For the field-testing phase, a cross-sectional self-administered survey of JoinCT was conducted among cancer patients with various socio-demographic backgrounds and medical conditions. Besides content validity, Cronbach's alpha was used to evaluate the internal consistency of domains, and confirmatory factor analysis was used to evaluate the model fit of the JoinCT framework. RESULTS: A total of 389 respondents participated in the survey. Based on the results obtained from a field data collection phase, JoinCT consisted of four independent variables domains, namely "knowledge", "perception of benefits", "perception of risks", and "confidence". The only dependent variable was the willingness to participate in a clinical trial. The minimum Cronbach's alpha was 0.937, and the model fit for the overall framework of JoinCT is also excellent with Comparative Fit Index (> 0.90), root mean square error approximation (< 0.08), and Standardized Root Mean Square Residual (< 0.08). CONCLUSIONS: The Join Clinical Trial Questionnaire (JoinCT) was successfully validated with excellent reliability and validity, and a good model fit. The main factors that contribute to willingness to participate in clinical trials are knowledge, perception of benefits, perception of risks, and confidence.