Diagnostic value of ultrathin bronchoscopy in peripheral pulmonary lesions: a narrative review

Development of the Korean Association for Lung Cancer Clinical Practice Guidelines: Recommendations on Radial Probe Endobronchial Ultrasound for Diagnosing Lung Cancer - An Updated Meta-Analysis

PURPOSE

Radial probe endobronchial ultrasound (RP-EBUS) accurately locates peripheral lung lesions (PLLs) during transbronchial biopsy (TBB). We performed an updated meta-analysis of the diagnostic yield of TBB for PLLs using RP-EBUS to generate recommendations for the development of the Korean Association of Lung Cancer guidelines.

MATERIALS AND METHODS

We systematically searched MEDLINE and EMBASE (from January 2013 to December 2022), and performed a meta-analysis using R software. The diagnostic yield was evaluated by dividing the number of successful diagnoses by the total lesion number. Subgroup analysis was performed to identify related factors.

RESULTS

Forty-one studies with a total of 13,133 PLLs were included. The pooled diagnostic yield of RP-EBUS was 0.72 (95% confidence interval [CI], 0.70 to 0.75). Significant heterogeneity was observed among studies (χ2=292.38, p < 0.01, I2=86.4%). In a subgroup analysis, there was a significant difference in diagnostic yield based on RP-EBUS findings (within, adjacent to, invisible), with a risk ratio of 1.45 (95% CI, 1.23 to 1.72) between within and adjacent to, 4.20 (95% CI, 1.89 to 9.32) between within and invisible, and 2.59 (95% CI, 1.32 to 5.01) between adjacent to and invisible. There was a significant difference in diagnostic yield based on lesion size, histologic diagnosis, computed tomography (CT) bronchus sign, lesion character, and location from the hilum. The overall complication rate of TBB with RP-EBUS was 6.8% (bleeding, 4.5%; pneumothorax, 1.4%).

CONCLUSION

Our study showed that TBB with RP-EBUS is an accurate diagnostic tool for PLLs with good safety profiles, especially for PLLs with within orientation on RP-EBUS or positive CT bronchus sign.

Chinese expert consensus on cone-beam CT-guided diagnosis, localization and treatment for pulmonary nodules

Cone-beam computed tomography (CBCT) system can provide real-time 3D images and fluoroscopy images of the region of interest during the operation. Some systems can even offer augmented fluoroscopy and puncture guidance. The use of CBCT for interventional pulmonary procedures has grown significantly in recent years, and numerous clinical studies have confirmed the technology's efficacy and safety in the diagnosis, localization, and treatment of pulmonary nodules. In order to optimize and standardize the technical specifications of CBCT and guide its application in clinical practice, the consensus statement has been organized and written in a collaborative effort by the Professional Committee on Interventional Pulmonology of China Association for Promotion of Health Science and Technology.

Balloon Dilatation for Bronchoscope Delivery in a Swine Model: A Novel Technique for Ultra-Peripheral Lung Field Access and Accurate Biopsy

INTRODUCTION

In transbronchial biopsy of peripheral pulmonary lesions, the bronchoscope can reach only a limited depth due to the progressive narrowing of bronchi, which may reduce the diagnostic rate. This study examined the balloon dilatation for bronchoscope delivery (BDBD) technique, employing a novel balloon device to enhance bronchoscopy into the peripheral lung areas.

METHODS

Anaesthetised swine served as our primary model. Using computed tomography (CT) scans, we positioned virtual targets characterised by a positive bronchus sign and a diameter of 20 mm beneath the pleura. The bronchoscope was navigated along the pathways determined from the CT images. We performed balloon dilatation when bronchial narrowing obstructed progress to assess whether balloon dilatation would enable the bronchoscope to enter further into the periphery.

RESULTS

We established 21 virtual targets on the CT scans. An average of 12.1 branches were identified along the pathways on the CT scans; however, bronchoscopy without BDBD only allowed access to an average of 6.7 branches. Based on 72 balloon dilatations with 3.0-mm or 4.0-mm ultra-thin bronchoscopes, there was an average increased access of 3.43 and 5.14 branches per route, respectively, with no significant BDBD complications. The bronchoscope was able to reach the planned location along all pathways, and the mean final bronchoscopic endpoints were at an average distance of 14.7 mm from the pleura. Post-procedure CT confirmed biopsy accuracy.

CONCLUSION

The BDBD technique can enhance access of a flexible bronchoscope into the peripheral lung fields, which could potentially allow more accurate transbronchial interventions for peripheral targets.

Transbronchial cryobiopsy for small peripheral pulmonary lesions using endobronchial ultrasonography and an ultrathin bronchoscope

BACKGROUND

Transbronchial biopsy using an ultrathin bronchoscope (UTB) has a high diagnostic yield for peripheral pulmonary lesions (PPLs). When combined with peripheral transbronchial needle aspiration (pTBNA), it improves the diagnostic yield of "adjacent to" radial endobronchial ultrasonography (rEBUS) findings. However, pTBNA is a complicated technique, and the specimen volume is often inadequate for diagnostic and multiplex analyses. Recently, transbronchial cryobiopsy (TBCB) using a 1.1-mm cryoprobe that could be inserted into an UTB has been available. We investigated whether TBCB combined with forceps biopsy using a 1.1-mm cryoprobe with an UTB improved the diagnostic yield of "adjacent to" lesions.

METHODS

The data of 66 consecutive patients who underwent TBCB and forceps biopsy using UTB (hemostasis using two-scope method) under rEBUS for small PPLs (≤30 mm) were retrospectively analyzed. The histological diagnosis rate using TBCB and forceps biopsy, TBCB alone, or forceps biopsy alone was compared between cases where the rEBUS probe was "within" and "adjacent to" lesions.

RESULTS

The diagnosis rate using TBCB and forceps biopsy was 81.8 % for all lesions ("within" vs. "adjacent to" cases: 88.4 % vs. 69.6 %; p = 0.093). The corresponding rate using TBCB alone was 80.3 % (86.0 % vs. 69.6 %; p = 0.19), and that using forceps biopsy alone was 62.1 % (74.4 % vs. 39.1 %; p = 0.008). Bleeding leading to discontinuation of the examination occurred in four (6.1 %) patients; however, in all cases, bleeding could be controlled endoscopically.

CONCLUSION

Forceps biopsy with TBCB during ultrathin bronchoscopy for small PPLs improved the diagnostic yield when the lesions were adjacent to the rEBUS probe.

[Advanced bronchoscopic techniques for the diagnosis of peripheral lung nodule]

The endoscopic diagnosis of peripheral lung nodules is a challenging aspect of oncological practice. More often than not inaccessible by traditional endoscopy, these nodules necessitate multiple imagery tests, as well as diagnostic surgery for benign lesions. Even though transthoracic ultrasonography has a high diagnostic yield, a sizeable complication rate renders it suboptimal. Over recent years, a number of safe and accurate navigational bronchoscopic procedures have been developed. In this first part, we provide an overview of the bronchoscopic techniques currently applied for the excision and diagnostic analysis of peripheral lung nodules; emphasis is laid on electromagnetic navigation bronchoscopy and the association of virtual bronchoscopy planner with radial endobronchial ultrasound. We conclude by considering recent innovations, notably robotic bronchoscopy.

Ultrathin bronchoscopy for diagnosing peripheral pulmonary lesions

Bronchoscopes are continuously improving. Increasingly, thinner bronchoscopes with larger working channels and better imaging quality are becoming available for clinical use. Concurrently, useful ancillary devices have been developed, such as radial probe endobronchial ultrasound (rEBUS) and navigation devices. Randomized studies have demonstrated the diagnostic superiority of ultrathin bronchoscopy over thin bronchoscopy under rEBUS and virtual bronchoscopic navigation guidance for small, peripheral pulmonary lesions. Furthermore, biopsy needles and cryoprobes have been miniaturized and adapted to the working channel of the new ultrathin bronchoscopes. Multi-modality and multi-instrumental ultrathin bronchoscopy using such new technologies has facilitated high diagnostic yields.

Close-to-lesion transbronchial biopsy: a novel technique to improve suitability of specimens for genetic testing in patients with peripheral pulmonary lesions

Bronchoscopy with radial-probe endobronchial ultrasound, a guide sheath, and electromagnetic navigation can improve the diagnostic yield of peripheral lung nodules. However, the suitability of specimens for genetic analysis remains unsatisfactory. We hypothesized that a transbronchial biopsy performed after closely approaching the bronchoscope tip to the lesion might provide more suitable specimens for genetic analysis. We enrolled 155 patients with peripheral pulmonary lesions who underwent bronchoscopy with a thin or ultrathin bronchoscope. Bronchoscopy was performed using virtual bronchoscopic navigation and radial-probe endobronchial ultrasound with a guide sheath. The bronchoscope tip was placed closer to the lesion during bronchoscopy to collect larger specimens with higher malignant cell content. The patients who underwent a close-to-lesion biopsy had higher rates of overall diagnostic yield, histopathological diagnostic yield, and specimen quality for genetic testing than those who did not. The significant determinants of the specimen's suitability were the close-to-lesion approach, within-the-lesion image, the use of standard 1.9-mm-forceps, and the number of cancer-cell-positive specimens. The significant predictors of the specimen's suitability for genetic analysis were close-to-lesion biopsy and the number of malignant cell-positive tissue samples. This study demonstrates that the close-to-lesion transbronchial biopsy significantly improves the suitability of bronchoscopic specimens for genetic analysis.

A Millimeter-Scale Soft Robot for Tissue Biopsy Procedures

While interest in soft robotics as surgical tools has grown due to their inherently safe interactions with the body, their feasibility is limited in the amount of force that can be transmitted during procedures. This is especially apparent in minimally invasive procedures where millimeter-scale devices are necessary for reaching the desired surgical site, such as in interventional bronchoscopy. To leverage the benefits of soft robotics in minimally invasive surgery, a soft robot with integrated tip steering, stabilization, and needle deployment capabilities is proposed for lung tissue biopsy procedures. Design, fabrication, and modeling of the force transmission of this soft robotic platform allows for integration into a system with a diameter of 3.5 mm. Characterizations of the soft robot are performed to analyze bending angle, force transmission, and expansion during needle deployment. In-vitro experiments of both the needle deployment mechanism and fully integrated soft robot validate the proposed workflow and capabilities in a simulated surgical setting.

Ultrathin bronchoscopic cryobiopsy of peripheral pulmonary lesions

BACKGROUND AND OBJECTIVE

Ultrathin bronchoscopy aids in the diagnosis of peripheral pulmonary lesions. However, both the working channel and the specimens are small. A 1.1-mm ultrathin cryoprobe that can enter the working channel of the ultrathin bronchoscope is now available, which may overcome the limitations of small specimen size. The aim of this study was to evaluate the feasibility, efficacy and safety of ultrathin bronchoscopic cryobiopsy using an ultrathin cryoprobe for diagnosing peripheral pulmonary lesions.

METHODS

Patients with peripheral pulmonary lesions ≤30 mm in diameter were prospectively enrolled in the study. All patients underwent forceps biopsy followed by cryobiopsy using a 3.0-mm ultrathin bronchoscope under radial probe endobronchial ultrasound guidance, virtual bronchoscopic navigation and fluoroscopic guidance. The primary endpoint was the feasibility of cryobiopsy.

RESULTS

In total, 50 patients with peripheral pulmonary lesions were enrolled in the study; the median longest diameter on computed tomography was 17.9 mm. Cryobiopsy was performed successfully in 49 patients (98%). Forceps biopsy, cryobiopsy and the combination of these two methods provided a specific diagnosis in 54% (27/50), 62% (31/50) and 74% (37/50) of patients, respectively. The median size of specimens obtained via cryobiopsy was significantly larger than the median size obtained via forceps biopsy (7.0 vs. 1.3 mm² , respectively, p < 0.001). Mild bleeding during cryobiopsy occurred in 47 patients (94%). No moderate/severe bleeding or pneumothorax occurred.

CONCLUSION

Ultrathin bronchoscopic cryobiopsy is feasible, effective and sufficiently safe for the diagnosis of peripheral pulmonary lesions.

Value of adding ultrathin bronchoscopy to thin bronchoscopy for peripheral pulmonary lesions: A multicentre prospective study

BACKGROUND AND OBJECTIVE

The diagnostic yield of thin bronchoscopy with radial probe endobronchial ultrasound (rEBUS) of peripheral pulmonary lesions into which the rEBUS probe cannot be inserted is unsatisfactory. In such cases, adding ultrathin bronchoscopy may be an option. We evaluated the efficacy of sequential ultrathin bronchoscopy for peripheral pulmonary lesions into which the rEBUS probe could not be inserted during thin bronchoscopy.

METHODS

In this multicentre prospective study, patients with peripheral pulmonary lesions ≤30 mm in diameter underwent rEBUS-guided transbronchial biopsy using a 4.0 mm diameter thin bronchoscope. In patients with lesions into which a rEBUS probe could not be inserted using that bronchoscope, bronchoscopy using a 3.0 mm diameter ultrathin bronchoscope was performed.

RESULTS

A total of 342 patients were enrolled and 340 were analysed. Among them, 87 patients with lesions of a median longest diameter of 17.5 mm underwent thin bronchoscopy followed by ultrathin bronchoscopy. Of the 87 patients, the rEBUS probe was successfully inserted into the lesions via the ultrathin bronchoscope in 50 patients (57.5%). Of the 87 patients, the diagnostic yields of thin bronchoscopy and ultrathin bronchoscopy were 12.6% (11 of 87) and 41.4% (36 of 87), respectively (p < 0.001).

CONCLUSION

Ultrathin bronchoscopy affords a higher diagnostic yield for lesions into which a rEBUS probe cannot be inserted via a thin bronchoscope.

Endoscopic Technologies for Peripheral Pulmonary Lesions: From Diagnosis to Therapy

Peripheral pulmonary lesions (PPLs) are frequent incidental findings in subjects when performing chest radiographs or chest computed tomography (CT) scans. When a PPL is identified, it is necessary to proceed with a risk stratification based on the patient profile and the characteristics found on chest CT. In order to proceed with a diagnostic procedure, the first-line examination is often a bronchoscopy with tissue sampling. Many guidance technologies have recently been developed to facilitate PPLs sampling. Through bronchoscopy, it is currently possible to ascertain the PPL's benign or malignant nature, delaying the therapy's second phase with radical, supportive, or palliative intent. In this review, we describe all the new tools available: from the innovation of bronchoscopic instrumentation (e.g., ultrathin bronchoscopy and robotic bronchoscopy) to the advances in navigation technology (e.g., radial-probe endobronchial ultrasound, virtual navigation, electromagnetic navigation, shape-sensing navigation, cone-beam computed tomography). In addition, we summarize all the PPLs ablation techniques currently under experimentation. Interventional pulmonology may be a discipline aiming at adopting increasingly innovative and disruptive technologies.

Ultrathin Bronchoscopy for the Diagnosis of Peripheral Pulmonary Lesions: A Meta-Analysis

BACKGROUND

Ultrathin bronchoscopy (external diameter, ≤3.5 mm) is useful for the diagnosis of peripheral pulmonary lesions because of its good accessibility.

OBJECTIVES

We performed a meta-analysis to investigate the diagnostic yield of ultrathin bronchoscopy for peripheral pulmonary lesions.

METHODS

We performed a systematic search of MEDLINE and EMBASE (from inception to May 2021), and meta-analysis was performed using R software. The diagnostic yield was evaluated by dividing the number of successful diagnoses by the total number of lesions, and subgroup analysis was performed to identify related factors.

RESULTS

Nineteen studies with a total of 1,977 peripheral pulmonary lesions were included. The pooled diagnostic yield of ultrathin bronchoscopy was 0.65 (95% confidence interval, 0.60-0.70). Significant heterogeneity was observed among studies (χ2, 87.75; p < 0.01; I2, 79.5%). In a subgroup analysis, ultrathin bronchoscopy with 1.2 mm channel size showed a diagnostic yield of 0.61 (95% confidence interval, 0.53-0.68), whereas ultrathin bronchoscopy with 1.7 mm channel size showed 0.70 (95% confidence interval, 0.66-0.74) (χ2, 5.35; p = 0.02). In addition, there was a significant difference in diagnostic yield based on lesion size, histologic diagnosis (malignant vs. benign), bronchus sign, and lesion location from the hilum, whereas no significant difference was found based on lobar location. The overall complication rate of ultrathin bronchoscopy was 2.7% (pneumothorax, 1.1%).

CONCLUSIONS

Ultrathin bronchoscopy is an excellent tool for peripheral pulmonary lesion diagnosis with a low complication rate. The diagnostic yield of ultrathin bronchoscopy was significantly higher with larger channel size, which might be attributed to the availability of radial endobronchial ultrasound.

Endobronchial removal of the peripherally located foreign body with the ultrathin bronchoscopy and ultrathin cryoprobe guided by a manual navigating method: A case report

RATIONAL

The bronchoscope is a preferential method used to remove airway foreign bodies, but for those located in the distal lumen of bronchus with long-time retention, how to remove them remains an intractable problem.

PATIENT CONCERNS

A 57-year-old male presented with 2-week history of intermittent hemoptysis. Chest CT upon admission revealed a high-density opacity incarcerated in the distal basal segment of the left lower lobe, along with obstructive pneumonia.

DIAGNOSES

The patient was diagnosed as foreign body aspiration.

INTERVENTIONS

We firstly used a manual navigating method to draw a bronchoscopic map according to the thin-section CT. Then we adopted ultrathin bronchoscope (UTB) to remove the peripherally located foreign body.

OUTCOMES

UTB successfully found the foreign body incarcerated in LB10ciiβ under the guidance of manual navigation, but it was too tender to be extracted completely by forceps, and it was even pushed further away. Then 1.1 mm ultrathin cryoprobe was used, with an activation time of 4 seconds, the chili was frozen and completely removed.

LESSONS

This first combined application of manual navigating method, UTB and ultrathin cryoprobe, successfully extracted foreign bodies lodged in the distal airways and thus avoided thoracic surgery.

Hierarchical clock-scale hand-drawn mapping as a simple method for bronchoscopic navigation in peripheral pulmonary nodule

Background

A feasible and economical bronchoscopic navigation method in guiding peripheral pulmonary nodule biopsy is lacking.

Objective

To investigate the utility of hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation in peripheral pulmonary nodules.

Methods

We developed a hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation in peripheral pulmonary nodules. Patients with peripheral pulmonary nodules were recruited and assigned to two groups in this retrospective study, subjects in VBN group received conventional bronchoscopy in conjunction with virtual bronchoscopic navigation (VBN) and radial probe endobronchial ultrasound (RP-EBUS) for biopsy (VBN group), while HBN group underwent ultrathin bronchoscopy and RP-EBUS under the guidance of hand-drawn bronchoscopic navigation (HBN). The demographic characteristics, procedural time, operating cost and diagnostic yield were compared between these two groups.

Results

Forty-eight patients with peripheral pulmonary nodule were enrolled in HBN group, while 42 in VBN group. There were no significant differences between VBN and HBN groups in terms of age, gender, lesion size, location and radiographic type. The time of planning pathway (1.32 vs. 9.79 min, P < 0.001) and total operation (23.63 vs. 28.02 min, P = 0.002), as well as operating cost (758.31 ± 125.21 vs.1327.70 ± 116.25 USD, P < 0.001) were markedly less in HBN group, compared with those in VBN group. The pathological diagnostic efficiency of benign and malignant disease in HBN group appeared similar with those in VBN group, irrespective of the size of pulmonary lesion (larger or smaller than 20 mm). The total diagnostic yield of HBN had no marked difference from that of VBN (75.00% vs. 61.90%, P = 0.25).

Conclusions

Hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation could serve as a feasible and economical method for guiding peripheral pulmonary nodule biopsy, providing a comparable diagnostic yield in comparison with virtual bronchoscopic navigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02160-0.

Ultrathin bronchoscope combined with virtual bronchoscopic navigation and endobronchial ultrasound for the diagnosis of peripheral pulmonary lesions with or without fluoroscopy: A randomized trial

Background

Transbronchial lung biopsy (TBLB) is usually performed to obtain a definitive diagnosis for peripheral pulmonary lesions (PPLs). Ultrathin bronchoscopy combined with virtual bronchoscopic navigation (VBN) and radial endobronchial ultrasound (R‐EBUS) are generally considered appropriate diagnostic methods for PPLs; however, they have not yet been explored in combination with fluoroscopy. Therefore, the present prospective randomized controlled trial determined the role of fluoroscopy in ultrathin bronchoscopy combined with VBN and R‐EBUS for the diagnosis of PPLs.

Methods

Patients with potentially malignant PPLs were enrolled in the study and randomized into fluoroscopy or nonfluoroscopy groups. In both groups, a 3.0‐mm outer and 1.7‐mm internal diameter ultrathin bronchoscope was used for transbronchial lung biopsy combined with R‐EBUS and VBN. In addition, the fluoroscopy group (FG) underwent fluoroscopy, while the nonfluoroscopy group (NFG) did not.

Results

A total of 126 patients were enrolled and randomized in the study. Among them, 120 patients (60 in the NFG and 60 in the FG) were analyzed. The mean lesion sizes were 26.3 ± 11.4 mm and 29.0 ± 11.3 mm in the NFG and FG, respectively. The diagnostic yield was 73.3% (44/60) in the NFG and 81.7% (49/60) in the FG without statistically significant difference (p = 0.38). No obvious complications occurred in either group.

Conclusions

Ultrathin bronchoscope combined with VBN and R‐EBUS without fluoroscopy is a feasible and safe diagnostic method for PPLs.