Electromagnetic navigation bronchoscopy (ENB): Increasing diagnostic yield

Breaking New Ground in Interventional Pulmonology: Integrating Cone Beam CT and Robotic-Assisted Bronchoscopy for High-Risk Pneumothorax in Peripherally Located Solitary Pulmonary Nodules

Lung cancer, a leading cause of global cancer-related deaths, necessitates the development of innovative diagnostic techniques. Traditional bronchoscopy, while useful, has limitations in diagnosing peripheral pulmonary lesions (PPLs) and carries a higher risk of complications such as pneumothorax. However, the field of interventional pulmonology has seen significant advancements, including the introduction of robotic-assisted bronchoscopy (RAB), cone-beam computed tomography (CBCT), radial endobronchial ultrasound (R-EBUS), and rapid on-site evaluation (ROSE). These advancements have greatly improved the precision of diagnosing high-risk PPLs. This report presents the case of a 60-year-old female smoker with chronic obstructive pulmonary disease and extensive centrilobular emphysema, who had a peripherally located high-risk pulmonary nodule. She was successfully diagnosed with metastatic adenocarcinoma using an integrated approach, despite the challenging location of the lesion and high risk of pneumothorax. The integration of RAB with CBCT and augmented fluoroscopy offers a groundbreaking approach for diagnosing and managing difficult-to-reach, high-risk pulmonary nodules, marking a significant stride in the field of interventional pulmonology.

Single Institution Evaluation of Electromagnetic Navigation Bronchoscopy for Diagnosis of Pulmonary Lesions

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) utilizes three-dimensional reconstructions based on computed tomography to guide the biopsy of pulmonary lesions. Various limitations have been described; however, supporting data have been limited by small sample sizes.

METHODS

Cases of ENB for evaluation of a pulmonary lesion at a single institution during a 1-year span were reviewed for demographics, lesion location, procedural details, and final tissue diagnosis. ENB was performed by 3 pulmonologists using the Veran platform with rapid on-site evaluation. T test or Mann-Whitney U test compared continuous variables and χ 2 or Fisher exact test compared categorical variables as appropriate. A patient with a negative or inconclusive biopsy was followed for 1 year postprocedure.

RESULTS

A total of 107 pulmonary lesions were evaluated. The population studied had a mean age of 67 and a median pulmonary lesion size of 26.0 mm. For malignant lesions, the pathologic diagnostic yield from ENB was 52.1% (37/71). The diagnostic yield of benign lesions was much lower at 16.7% (6/36). The overall procedural complication rate was 8.4% (9/107). Complications were more likely to occur in patients with malignant lesions. The most common complication was pneumothorax, occurring in 5.6% of all biopsies and 7.0% of patients with malignant lesions.

CONCLUSION

This study demonstrates significant differences in diagnostic accuracy between lesions found to be malignant versus benign. Our observed complication rate was slightly higher than other groups have reported, with a greater frequency occurring in patients with malignant lesions; however, the rate of pneumothorax was still lower than computed tomography-guided transcutaneous biopsies.

Diagnostic yield using electromagnetic navigation bronchoscopy for peripheral pulmonary nodules <2 cm

BACKGROUND

Although electromagnetic navigation bronchoscopy (ENB) is highly sensitive in the diagnosis of peripheral pulmonary nodules (PPNs), its diagnostic yield for subgroups of smaller PPNs is under evaluation.

OBJECTIVES

Diagnostic yield evaluation of biopsy using ENB for PPNs <2 cm.

DESIGN

The diagnostic yield, sensitivity, specificity, positive predictive value, and negative predictive value of the ENB-mediated biopsy for PPNs were evaluated.

METHODS

Patients who had PPNs with diameters <2 cm and underwent ENB-mediated biopsy between May 2015 and February 2020 were consecutively enrolled. The final diagnosis was made via pathological examination after surgery.

RESULTS

A total of 82 lesions from 65 patients were analyzed. The median tumor size was 11 mm. All lesions were subjected to ENB-mediated biopsy, of which 29 and 53 were classified as malignant and benign, respectively. Subsequent segmentectomy, lobectomy, or wedge resection, following pathological examinations were performed on 64 nodules from 57 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value for nodules <2 cm were 53.3%, 91.7%, 92.3%, and 51.2%, respectively. The receiver operating curve showed an area under the curve of 0.721 (p < 0.001). Additionally, the sensitivity, specificity, positive predictive value, and negative predictive value were 62.5%, 100%, 100%, and 42.9%, respectively, for nodules with diameters equal to or larger than 1 cm; and 30.8%, 86.7%, 66.7%, and 59.1%, respectively, for nodules less than 1 cm. In the subgroup analysis, neither the lobar location nor the distance of the PPNs to the pleura affected the accuracy of the ENB diagnosis. However, the spiculated sign had a negative impact on the accuracy of the ENB biopsy (p = 0.010).

CONCLUSION

ENB has good specificity and positive predictive value for diagnosing PPNs <2 cm; however, the spiculated sign may negatively affect ENB diagnostic accuracy. In addition, the diagnostic reliability may only be limited to PPNs equal to or larger than 1 cm.

The effect of combining different sampling tools on the performance of electromagnetic navigational bronchoscopy for the evaluation of peripheral lung lesions and factors associated with its diagnostic yield

BACKGROUND

We assessed the performance of Electromagnetic navigational bronchoscopy (ENB) as a standalone diagnostic technique and the performance of different sampling tools used during the procedure.

METHODS

We recruited 160 consecutive patients who underwent ENB for peripheral lung lesions (PLL) at a tertiary care centre. The diagnostic performance of ENB and sampling tools was assessed using a logistic regression model and a ROC-curve in which the dependent variable was diagnostic success. A multivariate model was built to predict diagnostic success before performing ENB to select the best candidates for the procedure.

RESULTS

Most patients with PLLs in the study were male (65%), with a mean age of 67.9 years. The yield was 66% when the most common techniques were used together as suction catheter + transbronchial biopsy forceps (TBBx) + bronchoalveolar lavage + bronchial washing (p < 0.001) and increased to 69% when transbronchial needle aspiration (TBNA) and cytology brush were added (p < 0.001). Adding diagnostic techniques such as TBBx and TBNA resulted in an increase in diagnostic performance, with a statistically significant trend (p = 0.002). The logistic model area-under the ROC-curve for diagnostic success during ENB was 0.83 (95% CI:0.75-0.90; p < 0.001), and a logit value ≥ 0.12 was associated with ≥ 50% probability of diagnostic success.

CONCLUSIONS

ENB, as a stand-alone diagnostic tool for the evaluation of PLLs when performed by experienced operators using a multi-modality technique, has a good diagnostic yield. The probability of having a diagnostic ENB could be assessed using the proposed model.

Diagnostic yield and safety of navigation bronchoscopy: A systematic review and meta-analysis

BACKGROUND

Navigation bronchoscopy has seen rapid development in the past decade in terms of new navigation techniques and multi-modality approaches utilizing different techniques and tools. This systematic review analyses the diagnostic yield and safety of navigation bronchoscopy for the diagnosis of peripheral pulmonary nodules suspected of lung cancer.

METHODS

An extensive search was performed in Embase, Medline and Cochrane CENTRAL in May 2022. Eligible studies used cone-beam CT-guided navigation (CBCT), electromagnetic navigation (EMN), robotic navigation (RB) or virtual bronchoscopy (VB) as the primary navigation technique. Primary outcomes were diagnostic yield and adverse events. Quality of studies was assessed using QUADAS-2. Random effects meta-analysis was performed, with subgroup analyses for different navigation techniques, newer versus older techniques, nodule size, publication year, and strictness of diagnostic yield definition. Explorative analyses of subgroups reported by studies was performed for nodule size and bronchus sign.

RESULTS

A total of 95 studies (n = 10,381 patients; n = 10,682 nodules) were included. The majority (n = 63; 66.3%) had high risk of bias or applicability concerns in at least one QUADAS-2 domain. Summary diagnostic yield was 70.9% (95%-CI 68.4%-73.2%). Overall pneumothorax rate was 2.5%. Newer navigation techniques using advanced imaging and/or robotics(CBCT, RB, tomosynthesis guided EMN; n = 24 studies) had a statistically significant higher diagnostic yield compared to longer established techniques (EMN, VB; n = 82 studies): 77.5% (95%-CI 74.7%-80.1%) vs 68.8% (95%-CI 65.9%-71.6%) (p < 0.001).Explorative subgroup analyses showed that larger nodule size and bronchus sign presence were associated with a statistically significant higher diagnostic yield. Other subgroup analyses showed no significant differences.

CONCLUSION

Navigation bronchoscopy is a safe procedure, with the potential for high diagnostic yield, in particular using newer techniques such as RB, CBCT and tomosynthesis-guided EMN. Studies showed a large amount of heterogeneity, making comparisons difficult. Standardized definitions for outcomes with relevant clinical context will improve future comparability.

Evaluation of Electromagnetic Navigational Bronchoscopy Using Tomosynthesis-Assisted Visualization, Intraprocedural Positional Correction and Continuous Guidance for Evaluation of Peripheral Pulmonary Nodules

BACKGROUND

Electromagnetic navigational bronchoscopy (ENB) has been shown to have variable diagnostic accuracy for the assessment of peripheral pulmonary nodules. This may be because of discrepancies between the preplanned computed tomography of chest target lesion location versus actual target location (computed tomography-to-body divergence), and the lack of a continuous navigational image. The ILLUMISITE (Medtronic, Minneapolis, MN) is a newly developed ENB platform that utilizes tomosynthesis, an imaging technology that can visualize the target location using fluoroscopy (F-ENB). This new system also allows for intraprocedural positional correction and continuous navigation guidance during sampling to overcome these limitations and improve diagnostic yield. We report our first experience in a single center, single proceduralist using this new technology.

METHODS

We conducted a retrospective, single center, single operator study reviewing 72 consecutive patients (78 nodules) over a 3-month period. We investigated the overall diagnostic yield and diagnostic yield by nodule location, size, and sedation type using this new F-ENB system.

RESULTS

The overall diagnostic yield was 87% and pnemothoraces occurred in 2/78 procedures. We did not find any statistically significant difference when comparing pulmonary nodule location, size or sedation method utilized ( P =0.231, 0.338, and 0.112, respectively). Sixty-nine percent of the pulmonary nodules biopsied were 2 to 3 cm in size. The average distance corrected after tomosynthesis visualization was 15.4 mm (0.4 to 29.8 mm).

CONCLUSION

We report our initial experience with the ILLUMISITE system using fluoroscopic tomosynthesis-assisted visualization with continuous navigational guidance at our institution. This new technology allows the operator to correct for better target lesion alignment and real time positional correction and may improve diagnostic yields with minimal complications for evaluation of peripheral pulmonary nodules.

When Pulmonologists Are Novice to Navigational Bronchoscopy, What Predicts Diagnostic Yield?

Predicting factors of diagnostic yield in electromagnetic navigation bronchoscopy (ENB) have been explored in a number of previous studies based on data from experienced operators. However, little is known about predicting factors when the procedure is carried out by operators in the beginning of their learning curve. We here aim to identify the role of operators' experience as well as lesion- and procedure characteristics on diagnostic yield of ENB procedures in the hands of novice ENB operators. Four operators from three centers without prior ENB experience were enrolled. The outcome of consecutive ENB procedures was assessed and classified as either diagnostic or non-diagnostic and predicting factors of diagnostic yield were assessed. A total of 215 procedures were assessed. A total of 122 (57%) of the ENB procedures resulted in diagnostic biopsies. Diagnostic ENB procedures were associated with a minor yet significant difference in tumor size compared to non-diagnostic/inconclusive ENB procedures (28 mm vs. 24 mm; p = 0.03). Diagnostic ENB procedures were associated with visible lesions at either fluoroscopy (p = 0.003) or radial endobronchial ultrasound (rEBUS), (p = 0.001). In the logistic regression model, lesion visibility on fluoroscopy, but none of operator experience, the presence of a bronchus sign, lesion size, or location nor visibility on rEBUS significantly impacted the diagnostic yield. In novice ENB operators, lesion visibility on fluoroscopy was the only factor found to increase the chance of obtaining a diagnostic sample.

Size and vision: Impact of fluoroscopic navigation, digital tomosynthesis, and continuous catheter tip tracking on diagnostic yield of small, bronchus sign negative lung nodules

INTRODUCTION

Accurate biopsies of lung nodules, including small (<2 cm), bronchus sign negative lesions, remain challenging. Technological advances, however, may improve outcomes. We describe our experience using a novel system combining fluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking to guide lung nodule biopsies.

METHODS

Demographic data, procedural characteristics, and biopsy results from prospectively enrolled patients were collected.

RESULTS

159 nodules (144 patients) were biopsied. Average nodule size was 22.2 ± 15.2 mm (axial), 21.7 ± 13.9 mm (coronal), and 33.2 ± 20.5 mm (sagittal), with 45% (n = 72) <2 cm in all dimensions and 66% (n = 105) without a bronchus sign. Diagnostic yield was 84% (134/159), with malignancy (n = 75, 47%) most common. A diagnosis was obtained in 75% (n = 54/72) of lesions that were <2 cm in all dimensions and 79% (n = 83/105) of bronchus sign negative lesions. Unadjusted generalized mixed-effects logistic regression models showed that nodule size as a categorical variable (>2 cm in any dimension) and as a continuous variable in the coronal dimension, the presence of a bronchus sign, and a concentric radial EBUS view had an increased odds ratio for diagnosis. A concentric radial EBUS view also had an increased OR for diagnosis in a fully adjusted mixed-effects logistic regression model.

CONCLUSION

Fluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking shows an overall improved diagnostic accuracy compared to historical controls, including for small, bronchus sign negative lesions. Future studies clarifying the optimal modality for patients with different nodules will be of importance to provide the most appropriate procedure tailored to each individual lesion's unique characteristics.

A Novel Electromagnetic Navigation Bronchoscopy System for the Diagnosis of Peripheral Pulmonary Nodules: A Randomized Trial

RATIONALE

Endobronchial ultrasound (EBUS) combined with a guide sheath (GS) as an instrument for confirming the proximity of the bronchoscope and its relationship to the lesion can increase the diagnostic yield when conducting transbronchial lung biopsy of peripheral pulmonary nodules (PPNs). A novel electromagnetic navigational bronchoscopy (ENB) system comprising a thinner locatable sensor probe as a guidance instrument was developed to be suitable for a thin bronchoscope with a 2-mm-diameter working channel. The diagnostic efficacy of EBUS-GS with or without this ENB system has not been confirmed.

OBJECTIVES

To compare the diagnostic value and safety of EBUS-GS with or without ENB system for diagnosing PPNs.

METHODS

A prospective, multicenter, randomized controlled clinical trial was designed and conducted at 3 centers. Patients with PPNs suspected to be malignant were enrolled and randomly assigned to the ENB-EBUS-GS group or EBUS-GS group. The primary endpoint was the diagnostic yield in each group. The secondary endpoint was the procedural time and other factors affecting diagnostic yield. The safety endpoint was procedural complications.

RESULTS

Four hundred participants were enrolled from July 2018 to October 2019 and 385 patients were analyzed, with 193 in the ENB-EBUS-GS group and 192 in the EBUS-GS group. The mean nodule size was 21.7±5.3 mm. The diagnostic yields were 82.9% (95% confidence interval (CI), 77.6%-88.2%) in the ENB-EBUS-GS group and 73.4% (95% CI, 67.2%-79.7%) in the EBUS-GS group. The difference between the two groups was 9.5% (95% CI, 2.6%-16.3%), with an adjusted difference of 9.0% (95% CI, 2.3%-15.8%), after adjusting for the stratification factors and center. The time for finding lesions in the ENB-EBUS-GS was shorter than that in the EBUS-GS group (213.2±145.6s vs. 264.8±189.5s, p=0.003). And intraoperative hemorrhage occurred 3.6% in the ENB-EBUS-GS group and 3.1% in the EBUS-GS group, without significant differences between the two groups.

CONCLUSIONS

The novel ENB system combined with EBUS-GS demonstrated improved ability to locate PPNs, achieving a high diagnostic yield for PPNs compared to EBUS-GS alone in a safe and efficient procedure. Clinical trial registered with ClinicalTrials.gov (NCT03569306).

Predictors of Success When Implementing an Electromagnetic Navigational Bronchoscopy Program

INTRODUCTION

With the advent of lung cancer screening, lung nodules are being discovered at an increasing rate. With improvements in transbronchial biopsy technology, it is important for thoracic surgeons to be involved with diagnostic procedures. The aim of this project is to relate the thoracic surgeon experience in implementing an electromagnetic navigational bronchoscopy (ENB) program at our institution and describe the factors that led to successful navigation (the ability to position a biopsy instrument in range for biopsy) and diagnostic biopsy of nodules.

METHODS

The thoracic surgery ENB program was initiated in 2014. A retrospective analysis of patients referred to thoracic surgery from 2014 to 2019 for lung nodule evaluation was performed. Patients who underwent ENB and biopsy were included. Recursive partitioning (CART) and multivariable regression analyses were used to identify predictors of successful navigation and biopsy.

RESULTS

There were 73 patients who underwent ENB evaluation of 91 nodules from 2014 to 2019. There was successful navigation in 75.8% of nodules, and on multivariable analysis, bronchus sign, lesion size, and pleural distance were significant predictors of successful navigation. Of the lesions that had successful navigation, 65.2% had a diagnostic biopsy. Based on CART analysis, positive bronchus sign and lesion size ≥ 1.3 cm were most predictive of obtaining a diagnostic biopsy with a probability of 0.75.

CONCLUSIONS

Nodule size, distance to the pleura, and bronchus size are independent variables of successful navigation when using ENB. However, of the lesions that were successfully reached, combined lesion size >1.3 cm and a positive bronchus sign were most predictive of obtaining a diagnostic biopsy. These factors should be considered when implementing an ENB program in a thoracic surgery practice.

Advances in Diagnostic Bronchoscopy

The increase in incidental discovery of pulmonary nodules has led to more urgent requirement of tissue diagnosis. The peripheral pulmonary nodules are especially challenging for clinicians. There are various modalities for diagnosis and tissue sampling of pulmonary lesions, but most of these modalities have their own limitations. This has led to the development of many advanced technical modalities, which have empowered pulmonologists to reach the periphery of the lung safely and effectively. These techniques include thin/ultrathin bronchoscopes, radial probe endobronchial ultrasound (RP-EBUS), and navigation bronchoscopy—including virtual navigation bronchoscopy (VNB) and electromagnetic navigation bronchoscopy (ENB). Recently, newer technologies—including robotic-assisted bronchoscopy (RAB), cone-beam CT (CBCT), and augmented fluoroscopy (AF)—have been introduced to aid in the navigation to peripheral pulmonary nodules. Technological advances will also enable more precise tissue sampling of smaller peripheral lung nodules for local ablative and other therapies of peripheral lung cancers in the future. However, we still need to overcome the CT-to-body divergence, among other limitations. In this review, our aim is to summarize the recent advances in diagnostic bronchoscopy technology.

4D Electromagnetic Navigation Bronchoscopy for the Sampling of Pulmonary Lesions: First European Real-Life Experience

Purpose

The use of Electromagnetic navigation bronchoscopy (ENB) for the diagnosis of pulmonary peripheral lesions is still debated due to its variable diagnostic yield; a new 4D ENB system, acquiring inspiratory and expiratory computed tomography (CT) scans, overcomes respiratory motion and uses tracked sampling instruments, reaching higher diagnostic yields. We aimed at evaluating diagnostic yield and accuracy of a 4D ENB system in sampling pulmonary lesions and at describing their influencing factors.

Methods

We conducted a three-year retrospective observational study including all patients with pulmonary lesions who underwent 4D ENB with diagnostic purposes; all the factors potentially influencing diagnosis were recorded.

Results

103 ENB procedures were included; diagnostic yield and accuracy were, respectively, 55.3% and 66.3%. We reported a navigation success rate of 80.6% and a diagnosis with ENB was achieved in 68.3% of cases; sensitivity for malignancy was 61.8%. The majority of lesions had a bronchus sign on CT, but only the size of lesions influenced ENB diagnosis (p < 0.05). Transbronchial needle aspiration biopsy was the most used tool (93.2% of times) with the higher diagnostic rate (70.2%). We reported only one case of pneumothorax.

Conclusion

The diagnostic performance of a 4D ENB system is lower than other previous navigation systems used in research settings. Several factors still influence the reachability of the lesion and therefore diagnostic yield. Patient selection, as well as the multimodality approach of the lesion, is strongly recommended to obtain higher diagnostic yield and accuracy, with a low rate of complications.

Diagnostic Performance of Electromagnetic Navigation Bronchoscopy-Guided Biopsy for Lung Nodules in the Era of Molecular Testing

Electromagnetic navigation bronchoscopy (ENB) is an emerging technique used to evaluate peripheral lung lesions. The aim of this study was to determine the diagnostic yield, safety profile, and adequacy of specimens obtained using ENB for molecular testing. This single-center, prospective pilot study recruited patients with peripheral pulmonary nodules that were not suitable for biopsy via percutaneous transthoracic needle biopsy methods. The possibility of molecular testing, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), and programmed death ligand 1 (PD-L1), was identified with non-small cell lung cancer (NSCLC) tissue obtained using ENB. ENB-guided biopsy was performed on 30 pulmonary nodules in 30 patients. ENB-guided biopsy was successfully performed in 96.6% (29/30) of cases, but one case failed to approach the target lesion. The diagnostic accuracy of ENB-guided biopsy was 68.0% (17/25). Biopsy-related pneumothorax occurred in one patient and there was no major bleeding or deaths related to the procedure. Among 13 patients diagnosed with NSCLC, molecular testing was successfully performed in 92.3% (12/13). ENB-guided biopsy demonstrated acceptable accuracy and excellent sample adequacy, with a high possibility of achieving molecular testing and a good safety profile to evaluate peripheral pulmonary nodules, even when the percutaneous approach was difficult and/or dangerous.

The Impact of Biopsy Tool Choice and Rapid On-Site Evaluation on Diagnostic Accuracy for Malignant Lesions in the Prospective: Multicenter NAVIGATE Study

BACKGROUND

The diagnostic yield of electromagnetic navigation bronchoscopy (ENB) is impacted by biopsy tool strategy and rapid on-site evaluation (ROSE) use. This analysis evaluates usage patterns, accuracy, and safety of tool strategy and ROSE in a multicenter study.

METHODS

NAVIGATE (NCT02410837) evaluates ENB using the superDimension navigation system (versions 6.3 to 7.1). The 1-year analysis included 1215 prospectively enrolled subjects at 29 United States sites. Included herein are 416 subjects who underwent ENB-aided biopsy of a single lung lesion positive for malignancy at 1 year. Use of a restricted number of tools (only biopsy forceps, standard cytology brush, and/or bronchoalveolar lavage) was compared with an extensive multimodal strategy (biopsy forceps, cytology brush, aspirating needle, triple needle cytology brush, needle-tipped cytology brush, core biopsy system, and bronchoalveolar lavage).

RESULTS

Of malignant cases, 86.8% (361/416) of true positive diagnoses were obtained using extensive multimodal strategies. ROSE was used in 300/416 cases. The finding of malignancy by ROSE reduced the total number of tools used. A malignant ROSE call was obtained in 71% (212/300), most (88.7%; 188/212) by the first tool used (49.5% with aspirating needle, 20.2% with cytology brush, 17.0% with forceps). True positive rates were highest for the biopsy forceps (86.9%) and aspirating needle (86.6%). Use of extensive tool strategies did not increase the rates of pneumothorax (5.5% restricted, 2.8% extensive) or bronchopulmonary hemorrhage (3.6% restricted, 1.1% extensive).

CONCLUSION

These results suggest that extensive biopsy tool strategies, including the aspirating needle, may provide higher true positive rates for detecting lung cancer without increasing complications.

Invasive modalities for the diagnosis of peripheral lung nodules

INTRODUCTION

Lung nodules are being increasingly discovered either incidentally or through lung cancer screening chest CT scans. Some of these will turn out to be malignant and therefore it is important to obtain an accurate and timely diagnosis of lung cancer when suspected.

AREAS COVERED

This review will cover various invasive diagnostic modalities available to sample lung nodules. Data from key studies, obtained from PubMed searches, will be reviewed. Emerging technologies such as cone-beam CT and robotic-assisted bronchoscopies will be discussed along with ddata available currently to support their use.

EXPERT OPINION

The best approach to diagnosing a lung nodule - whether found incidentally or because of lung cancer screening - is continuously evolving. While CT-guided lung nodule biopsy has a high diagnostic yield, the risk of pneumothorax is often a concern. Bronchoscopy has a better safety profile, but diagnostic ability falls short of CT-guided biopsy. Existing technologies such as electromagnetic navigation have not demonstrated a high diagnostic yield. Factors responsible for this relatively lower low diagnostic yield will be discussed in detail. Emerging technologies such as cone-beam CT scan and robotic bronchoscopy have addressed some of these issues and initial experience has demonstrated better diagnostic yield.

Diagnostic yield and safety of biopsy guided by electromagnetic navigation bronchoscopy for high-risk pulmonary nodules

Background

Electromagnetic navigation bronchoscopy (ENB) is a useful method to obtain tissue for peripheral lung nodules. We aimed to understand the diagnostic yield and safety profile in high‐risk pulmonary nodules that cannot be accessed by percutaneous transthoracic needle biopsy.

Methods

In this single‐center retrospective study, we reviewed patients who underwent ENB for high‐risk pulmonary nodules. All procedures were performed under moderate sedation using intravenous midazolam and fentanyl.

Results

A total of 100 pulmonary nodules in 90 patients were subjected to ENB between October 2018 and May 2020. The median age of the study population was 66 (59–73). The mean diameter of the lung nodules was 27.9 mm. The diagnostic yield of ENB‐guided biopsy was 53.0%. Although the nodule size (odds ratio: 1.055, p = 0.007) and positive bronchus sign (odds ratio: 2.918, p = 0.020) were associated with the diagnostic yield during univariate analysis, nodule size was the only independent variable on the multivariable analysis. Interestingly, the diagnostic yield showed an upward trend after 60 cases, from 45%–65%. Procedure‐related complications were reported in 16 cases; among these, pneumothorax occurred in three cases, and four cases experienced moderate bleeding. No instance of major bleeding or death was linked to ENB‐guided biopsy.

Conclusion

ENB‐guided biopsy for high‐risk pulmonary nodules demonstrated an acceptable diagnostic yield and good safety profile. Moreover, the diagnostic yield was associated with nodule size and procedure experience.

Lesion characteristics affecting yield of electromagnetic navigational bronchoscopy

RATIONALE

Electromagnetic navigational bronchoscopy (ENB) is an important, minimally invasive diagnostic tool for malignant and benign peripheral lung lesions, offering lower complication risks than transthoracic needle aspirations. As a relatively new technology, the best sampling modality and lesion characteristics for ENB has yet to be determined. We evaluated the sensitivity and diagnostic yield of different sampling modalities (needle aspiration, brush biopsy, transbronchial forceps biopsies) and radiographical lesion characteristics by Tsuboi classification. We also evaluated the difference in yield and sensitivity with the addition of radial probe EBUS to augment ENB.

METHODS

We completed a retrospective chart review of all patients that had ENB performed at our institution since its implementation in 2011. We reviewed the lesion size, location, Tsuboi classification, cytology, pathology results and analyzed biopsy specimen tool types.

RESULTS

We included a total of 248 patients who had ENB performed between 2011 and 2018. Average age was 67 years and 50% female. A total of 270 lesions were targeted with a mean size of 24 ± 12 mm. Sensitivity for malignancy was 59.2% with a diagnostic yield of 72.3%. Sensitivity and diagnostic accuracy trended higher with combined sampling modalities (brush and transbronchial needle aspiration and forcep biopsy). Lesions with type I and type II Tsuboi classification of bronchus sign had higher sensitivity compared to type III classification (67.9% [n = 101 type I], 64.6% [n = 65 type II], 37.9% [n = 36 type III]), p = 0.01 and p = 0.04.

CONCLUSION

For navigation bronchoscopy, sensitivity is higher in bronchus sign lesions that end directly into lesion (Tsuboi type I) and travel through malignant lesions (Tsuboi type II) compared to tangentially circumventing the lesion (Tsuboi type III).

Electromagnetic Navigation Bronchoscopy Combined Endobronchial Ultrasound in the Diagnosis of Lung Nodules

ABSTRACT

Electromagnetic navigational bronchoscopy (ENB) combined with a radial endobronchial ultrasound probe realizes a combination of magnetic navigation and ultrasound imaging, allowing for the accurate navigation of peripheral lung lesions in real time during surgery. ENB has been evaluated in many studies. However, a comparative report on the feasibility of ENB combined radial endobronchial ultrasound diagnosis in different density lung nodules was small, and few of these studies have reported long-term follow-up results to exclude false negative results. The aim of this study is to explore the applicability of ENB combined radial endobronchial ultrasound in the diagnosis of lung nodules with different densities.Patients underwent biopsy in our medical center from 2016-09 to 2019-03 were divided into 2 groups: the solid nodule group and the subsolid pulmonary nodule group. We collected and analyzed the diagnostic accuracy, the diagnostic yield, the false negative rate and the incidence of complications between these 2 groups.A total of 37 lesions in 25 patients were biopsied, 14 lesions were subsolid pulmonary nodules and 23 were solid nodules. The diagnostic accuracy (success rate to obtain meaningful pathology tissues) was 34/37 (91.8%). Lost to follow-up in 1 case and three cases were undiagnosed. After at least 12 months of follow-up, the total diagnostic yield (true positive rate+ true negative rate) was 27/36 (75%) (P = .006). The false negative rate was 9/19 (47.3%) (P = .26). Complications occurred in 1/36 (2.7%) lesions. For the subsolid pulmonary nodule group, the diagnostic accuracy was 13/14 (92.8%) and the diagnostic yield was 7/14 (50%). For the solid nodule group, the diagnostic accuracy was 21/23 (91.3%), and the diagnostic yield was 20/22 (90.9%).Electromagnetic navigational bronchoscopy combined with radial endobronchial ultrasound in peripheral lung nodule biopsies is safe and effective, especially for solid nodules, but the diagnostic yield in subsolid nodule biopsies remains to be improved.

Diagnostic yield of electromagnetic navigational bronchoscopy: A safety net community-based hospital experience in the United States

INTRODUCTION:

Electromagnetic navigational bronchoscopy (ENB) is an excellent tool to diagnose peripheral pulmonary nodules, especially in the setting of emphysema and pulmonary fibrosis. However, most of these procedures are done by interventional pulmonologists and academic tertiary centers under general anesthesia. Studies evaluating the diagnostic utility of this tool in safety-net community hospitals by pulmonologists not formally trained in this technology are lacking. The objective was to evaluate the diagnostic yield of ENB done in such a setting and its associated complications.

METHODS:

Retrospective chart review of consecutive ENB procedures over 5 years from 2014, since its inception in our institution-a safety-net community based hospital was performed. Multiple variables were analyzed to assess their impact on diagnostic yields.

RESULTS:

After exclusion criteria were applied, 72 patients with 76 procedures were eventually included within our study, with an overall 1-year diagnostic yield of 80.2%. Sensitivity for malignancy was 73% and negative predictive value of 65%. Primary lung cancer was the most common diagnosis obtained, followed by tuberculosis (TB). The overall complication rates were low, with only 1 patient (1.3%) requiring hospitalization due to pneumothorax needing tube thoracostomy. No deaths or respiratory failures were noted within the cohort. The only significant variable affecting diagnostic yield was forced expiratory volume in 1 s. The presence of emphysema did not affect diagnostic yield.

CONCLUSIONS:

ENB is safe and feasible with a high diagnostic success rate even when performed by pulmonologists not formally trained in interventional pulmonology in low resource settings under moderate sedation.

Electromagnetic navigation bronchoscopy as an adjunct diagnostic tool in the Danish lung cancer diagnostic pathway: an initial retrospective single centre series

Background

The performance of electromagnetic navigation bronchoscopy (ENB) is reported with substantial variation, which may question its clinical usefulness. However, ENB may hold its true value when used as an additional minimal invasive diagnostic option before potential surgery in selected diagnostically challenging patients where traditional diagnostic methods have failed. We evaluated the safety and performance of ENB when used as an adjunct diagnostic tool in the Danish lung cancer diagnostic pathway (DLCDP) and its ability to reduce surgical diagnostic procedures.

Methods

A retrospective study was performed on eighty-two consecutive patients at Odense University Hospital from June 2016 to March 2018 with diagnostically challenging pulmonary lesions referred for ENB as an adjunct diagnostic procedure under the DLCDP. Patients with benign or inconclusive ENB pathology were either referred for further biopsies, surgery or repeated computer tomography (CT) scans for surveillance purposes.

Results

Eighty-one ENB procedures were performed in 80 patients. In 87.7% of the cases previous diagnostic methods had been unsuccessful. The mean target diameter was 1.55 cm and the average follow-up duration was 11 months. The diagnostic accuracy was 75%, while the diagnostic yield/sensitivity, negative predictive value and negative likelihood ratio was 51%, 67% and 0.49, respectively. No pneumothoraces and only one intrapulmonary haemorrhage was recorded, which was managed conservatively. The learning curve revealed an increase in diagnostic accuracy from 67.5% to 82.9% when comparing the first 40 ENB procedures with the last 41 procedures, however, this was not statistically significant (p-value: 0.11).

Conclusions

ENB was found to be a safe procedure with an acceptable diagnostic accuracy and yield in highly selected diagnostically challenging patients. The introduction of ENB carried a notable learning curve but proved to be a valuable adjunct diagnostic option in the DLCDP, which may help to reduce the number of potentially unnecessary or harmful surgical procedures in frail patients.

Recent Advances in Interventional Pulmonology

The field of interventional pulmonology has grown rapidly since first being defined as a subspecialty of pulmonary and critical care medicine in 2001. The interventional pulmonologist has expertise in minimally invasive diagnostic and therapeutic procedures involving airways, lungs, and pleura. In this review, we describe recent advances in the field as well as up-and-coming developments, chiefly from the perspective of medical practice in the United States. Recent advances include standardization of formalized training, new tools for the diagnosis and potential treatment of peripheral lung nodules (including but not limited to robotic bronchoscopy), increasingly well-defined bronchoscopic approaches to management of obstructive lung diseases, and minimally invasive techniques for maximizing patient-centered outcomes for those with malignant pleural effusion.

Jet Ventilation Decreases Target Motion and Increases Yield of ENB Especially in Lesions With Negative Bronchus Sign

BACKGROUND

Electromagnetic navigational bronchoscopy (ENB) is used to obtain peripheral lung tissue samples for evaluation and staging of central and peripheral lung lesions. Jet ventilation delivers and maintains a sustained airway pressure at high frequency, chest wall and diaphragmatic movement is drastically reduced compared with traditional ventilation. The current study looks to examine the effectiveness of tissue sampling (diagnostic yield) while using jet ventilation on target-lesion movement when compared with traditional ventilation.

METHODS

A total of 36 patients received total intravenous anesthesia with both jet and traditional ventilation during ENB procedure where sensor to lesion displacement was recorded. When planning the ENB procedure, the presence or absence of a viable airway to the lesion was recorded. Sensor to lesion movement was recorded and compared for significance using χ and t tests, utilizing stringent P-values.

RESULTS

Overall patients with an airway to the lesion (n=23) had a higher proportion of successful diagnostic biopsies, 83% compared with those patients that lacked an airway to the lesion (n=13) 70% proportion of successful diagnostic biopsies. When using jet ventilation, the chance of nonzero displacement was 8.3% (0.14 mm), regardless of the presence of an airway. Compared with traditional ventilation, the chance of a nonzero displacement between the sensor and target-lesion was 83% (6.4 mm), independent of airway presence to the lesions.

CONCLUSION

In patients without an airway, jet ventilation significantly decreased target displacement when compared with traditional ventilation (2 vs. 17 mm). In patients with direct airway to the lesion, jet ventilation did not significantly decrease target displacement when compared with the traditional approach.

Slow-growing metastatic adenocarcinoma diagnosed via electro-navigational bronchoscopy

Here, we describe the case of a 67-year-old man who had been under surveillance for solitary pulmonary nodule for two years and was diagnosed with malignancy via electro-navigational bronchoscopy (ENB). Surveillance computed tomography scan of the thorax showed annual growth increments of the pulmonary nodule. In view of his Brock score showing a 35% probability of malignancy, the patient was subjected to ENB, and metastatic adenocarcinoma from the gastrointestinal tract was diagnosed. ENB was done using a machine on loan from Veran Medical Technologies. The procedure was successful, with no immediate or long-term complications. The diagnosis following histopathological examination was adenocarcinoma, and he was subsequently referred to our oncology unit for further management.

Electromagnetic navigation bronchoscopy for lung nodule evaluation. Patient selection, diagnostic variables and safety

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) is a relatively new technique to diagnose pulmonary lesions in patients with reduced lung function. Several parameters have been shown to affect diagnostic yield including patient selection. We performed a prospective registration of data on one hundred patients who consecutively underwent electromagnetic navigation bronchoscopy. Selection criteria, patient characteristics, lesion size, distance to pleura, location of the lesion and presence of bronchus sign on computed tomography were registered.

METHODS

Navigation was performed using the superDimension hardware and software system. Patients were referred to ENB from a multidisciplinary team conference. We did not use fluoroscopy, endobronchial ultrasound equipment, rapid onsite evaluation or general anesthesia during the procedure. All patients in whom no malignant diagnose was found were subsequently followed for two years in order to verify a benign nature of the pulmonary lesion.

RESULTS

One hundred and nine ENB procedures were performed between September 2009 and November 2014. Overall diagnostic yield was 68%. Twenty seven of 49 malignant tumors were found by ENB leading to a sensitivity for malignancy of 55%. The sensitivity for malignancy was significantly higher for lesions in the upper and middle lobes compared to the lower lobes (P = 0.01). Lesions size, distance to pleura and presence of bronchus sign did not affect sensitivity.

CONCLUSION

ENB is a safe diagnostic procedure in an everyday setting with an acceptable diagnostic yield even without addition of supportive diagnostic methods and offers a possibility to diagnose pulmonary nodules in patients for whom other diagnostic procedures are too hazardous or have proven unsuccessful.

[The role of electromagnetic navigation bronchoscopy in the diagnosis of peripheral pulmonary lesions]

INTRODUCTION

Electromagnetic navigation bronchoscopy (ENB) is a recent, minimally invasive procedure utilized to guide endoscopic diagnostic tools to peripheral pulmonary nodules. The place of this technology among other diagnostic procedures remains uncertain.

METHOD

We analyzed our 30 first months of ENB used in the diagnosis of 106 lesions in 101 patients, from June 2016 to December 2018. Follow-up and final diagnosis was completed for 95 lesions (90%).

RESULTS

ENB was performed for 3.5% of all patients referred for abnormal findings on pulmonary imaging, and represented 19% of second line procedures for peripheral pulmonary lesions. Procedures were performed under general anesthesia, with a mean duration of 35min. The sensitivity of ENB was 64% (95%CI: 52-74%) for lesions with a mean diameter of 21mm, with an improvement over time (sensitivity 69% in the last 18 months). The presence of a bronchus within the lesion (bronchus sign) was associated with an increased sensitivity of 74%. Pneumothorax occurred in 5 patients (5%) of which 4 required drainage. There was no hemoptysis, and no death related to the procedure.

CONCLUSION

ENB is a minimally invasive procedure reaching acceptable sensitivity in the most difficult patients. ENB can be recommended for the diagnosis of peripheral pulmonary nodules when no other procedure is successful or possible. Its use as a first choice procedure is, for the moment, limited by the cost, but must be weighed against that of non-diagnostic procedures, and the cost of complications of trans-thoracic lung biopsies.

Electromagnetic navigation bronchoscopy: the initial experience in Hong Kong

Background

Pulmonary nodules (PNs) are increasingly detected by thoracic computed tomography (CT). Traditional diagnostic modalities have their drawbacks. Electromagnetic navigation bronchoscopy (ENB) is gaining popularity in diagnosing small PNs. This study describes the diagnostic yield and complication rate of ENB in diagnosing PNs in which other diagnostic methods are considered to have low yield.

Methods

This is a retrospective study of the diagnostic yield and complication rate of ENB performed in the United Christian Hospital, Hong Kong, from April 2015 to June 2016. If a histological diagnosis was deemed necessary and flexible bronchoscopy (FB) was the preferred modality, patients were offered ENB if they have failed a conventional FB with fluoroscopy and radial endobronchoscopic ultrasonography (R-EBUS), or were perceived to have low yield because of the size or position of the PN.

Results

During the study period, 99 patients received ENB. An overall of 87 patients had non-resolved CT lesions and had specific pathologies identified (87.9%). The total number of malignant PNs was 67 (67.7%) in the entire cohort and tuberculosis (TB) accounted for 14 PNs (14.1%). The overall accuracy by ENB was 71.7%, sensitivity 67.8%, specificity 100% and negative predictive value 30%. Complications occurred in 3 patients: 1 pneumothorax (1.0%), 1 post-transbronchial biopsy (TBBx) bleeding (1.0%), 1 respiratory failure (1.0%). No patient died as a result of ENB or its complications.

Conclusions

For PNs not accessible by conventional FB/R-EBUS, ENB provides good diagnostic yield with low complication rate. It is a useful armamentarium to respiratory physicians and thoracic surgeons.

Peripheral Lung Nodule Diagnosis and Fiducial Marker Placement Using a Novel Tip-Tracked Electromagnetic Navigation Bronchoscopy System

BACKGROUND

Electromagnetic navigation (EMN) has improved bronchoscopic access to peripheral pulmonary nodules. A novel EMN system utilizing novel tip-tracked instruments for endobronchial [electromagnetic navigation bronchoscopy (ENB)] as well as transthoracic lung biopsy [electromagnetic-guided transthoracic needle aspiration (EMTTNA)] has become available. The system provides real-time feedback as well as the ability to biopsy lesions outside of the airway. These advances have the potential to improve diagnostic yield over previous EMN systems.

METHODS

We performed a retrospective review of consecutive peripheral bronchoscopy cases utilizing a novel EMN platform for biopsy and/or fiducial marker (FM) placement at a tertiary care university hospital. We analyzed factors that may influence diagnostic yield including lesion size.

RESULTS

Our study included 108 patients who underwent EMN-guided bronchoscopy between June 2015 and April 2017 for the diagnosis of peripheral lung lesions and/or the placement of FMs for stereotactic body radiotherapy. Ninety-three patients underwent biopsy utilizing ENB +/- EMTTNA. The combined diagnostic yield was 78%. EMTTNA provided a diagnosis for 5 patients in whom the ENB biopsy results were negative. Diagnostic yield by nodules <20, 20 to 30, and >30 mm in size was 30/45 (67%), 27/30 (90%), and 16/18 (89%), respectively. Sixty-five patients underwent FM placement with a total of 133 FM placed.

CONCLUSION

This novel tip-tracked EMN system incorporating both ENB and EMTTNA can guide biopsy and FM placement with a high degree of success and with a low complication rate. Multicentered prospective trials are required to develop algorithmic approaches to combine ENB and EMTTNA into a single procedure.

Using a Dedicated Interventional Pulmonology Practice Decreases Wait Time Before Treatment Initiation for New Lung Cancer Diagnoses

PURPOSE

While there is significant mortality and morbidity with lung cancer, early stage diagnoses carry a better prognosis. As lung cancer screening programs increase with more pulmonary nodules detected, expediting definitive treatment initiation for newly diagnosed patients is imperative. The objective of our analysis was to determine if the use of a dedicated interventional pulmonology practice decreases time delay from new diagnosis of lung cancer or metastatic disease to the chest to treatment initiation.

METHODS

Retrospective chart analysis was done of 87 consecutive patients with a new diagnosis of primary lung cancer or metastatic cancer to the chest from our interventional pulmonology procedures. Demographic information and time intervals from abnormal imaging to procedure and to treatment initiation were recorded.

RESULTS

Patients were older (mean age 69) and former or current smokers (72%). A median of 27 days (1-127 days) passed from our diagnostic biopsy to treatment initiation. A median of 53 total days (2-449 days) passed from abnormal imaging to definitive treatment. Endobronchial ultrasound-guided transbronchial needle aspiration was the most commonly used diagnostic procedure (59%), with non-small cell lung cancer the majority diagnosis (64%). For surgical patients, all biopsy-negative lymph nodes from our procedures were cancer-free at surgical excision.

CONCLUSIONS

Compared to prior reports from international and United States cohorts, obtaining a tissue biopsy diagnosis through a gatekeeper interventional pulmonology practice decreases median delay from abnormal imaging to treatment initiation. This finding has the potential to positively impact patient outcomes and requires further evaluation.

Cone-Beam CT With Augmented Fluoroscopy Combined With Electromagnetic Navigation Bronchoscopy for Biopsy of Pulmonary Nodules

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) has been widely adopted as a guidance technique for biopsy of peripheral lung nodules. However, ENB is limited by the lack of real-time confirmation of the biopsy devices. Intraprocedural cone-beam computed tomography (CBCT) imaging can be utilized to assess or confirm the location of biopsy devices. The aim of this study is to determine the safety and diagnostic yield (DY) of image fusion of intraprocedural CBCT data with live fluoroscopy (augmented fluoroscopy) during ENB-guided biopsy of peripheral lung nodules.

METHODS

Data from 75 consecutive patients who underwent biopsy with ENB was collected retrospectively. Patients underwent CBCT imaging while temporarily suspending mechanical ventilation. CBCT data were acquired and 3-dimensional segmentation of nodules was performed using commercially available software (OncoSuite). During ENB, the segmented lesions were projected and fused with live fluoroscopy enabling real-time 3-dimensional guidance.

RESULTS

A total of 93 lesions with a median size of 16.0 mm were biopsied in 75 consecutive patients. The overall DY by lesion was 83.7% (95% confidence interval, 74.8%-89.9%). Multivariate regression analysis showed no independent correlation between lesion size, lesion location, lesion visibility under standard fluoroscopy, and the presence of a bronchus sign with DY. Pneumothorax occurred in 3 patients (4%).

CONCLUSION

Intraprocedural CBCT imaging with augmented fluoroscopy is feasible and effective and is associated with high DY during ENB-guided biopsies.

Competence in navigation and guided transbronchial biopsy for peripheral pulmonary lesions

Options for non-surgical tissue diagnosis of the peripheral nodule include CT scan-guided TTNA, fluoroscopy-guided bronchoscopy, radial endobronchial ultrasound (EBUS), electromagnetic navigation bronchoscopy (ENB), and virtual bronchoscopy navigation (VBN). For physicians who choose to pursue non-surgical biopsy, the decision to perform CT scan-guided or ultrasound-guided TTNA, conventional bronchoscopy or bronchoscopy guided by EBUS, ENB, or VBN will depend on a number of factors. CT scan-guided TTNA is preferable for nodules located near the chest wall or for deeper lesions, provided that there is no need to go through the fissures and there is no surrounding emphysema. Ultrasound-guided TTNA requires contact between the lesion and the costal pleura. Bronchoscopic techniques are preferable for nodules ≥2 cm located near a patent bronchus, or in individuals at high risk for pneumothorax following TTNA. In most other situations, operator experience should guide the decision. Trainees must possess a perfect knowledge of anatomy and be fully competent in the interpretation of imaging (CT with contrast medium and PET) and have a thorough knowledge of navigation technology in all its complexities. Practical training can be performed on animal, cadaver or plastic models. In the last years, to improve diagnostic yield, navigational bronchoscopy has attracted significant attention.

Electromagnetic Navigation Bronchoscopy: Where Are We Now? Five Years of a Single-Center Experience

INTRODUCTION

Electromagnetic navigation (ENB) is a guidance tool used in the diagnosis of solitary pulmonary nodules (SPNs) and masses. Its diagnostic yield is highly variable (38-71%) and a recent study has put in doubt the role of ENB in sampling SPNs in a real-life setting. The aim of this study is to describe the 5-year experience of our center with ENB, analyzing the population, possible confounding factors, and the diagnostic yield and accuracy of this technique.

METHODS

We conducted a retrospective observational study including all consecutive patients who underwent ENB for SPNs and masses from January 2011 to December 2015.

RESULTS

We included 113 patients; 79% had SPNs, 21% masses. The majority were localized in the upper and middle lobes (80%) and 61% presented a bronchus sign. 54% of the patients had a previous negative fluoroscopy-guided bronchoscopy. ENB achieved the diagnosis in 78 patients (69%) with 64 malignant and 14 were benign lesions. The diagnostic yield and accuracy of ENB were respectively 0.69 and 0.76. The only factor influencing the ability to reach a diagnosis was the presence of bronchus sign (p = 0.002). No procedural complications were reported.

CONCLUSION

ENB is a safe procedure with a similar diagnostic yield in the real-life and research setting. Bronchus sign is an important factor in determining the diagnostic yield. ENB efficacy can be maximized by expertise and by a careful selection of each case.

Diagnostic yield of electromagnetic navigational bronchoscopy: results of initial 35 cases in a Japanese institute

Background

Electromagnetic navigational bronchoscopy (ENB) is a new bronchoscopic technique for navigational transbronchial lung biopsy (TBLB) that guides the sheath to the target lesion in real time. Herein, we report our experience with this navigational system, its diagnostic yields, and associated complications.

Methods

A single-center, single-operator retrospective chart review was performed. We included 35 consecutive patients who underwent ENB with superDimension^TM (Medtronic, MN, USA) for the diagnosis of pulmonary lesions from February 2016 to May 2017 in Kyoto University Hospital. The size of the target lesion varied from 8 to 25 mm (median, 15.28±5.48 mm). All ENB procedures were performed under conscious sedation using 2 to 10 mg midazolam and 1 to 10 mg morphine hydrochloride. No fluoroscopic guide was employed except in three cases.

Results

A total of 25 patients were diagnosed via ENB, yielding a diagnostic rate of 71.4% (25/35). The average lesion size of the diagnosed group was 16.44±5.44 mm (range, 8-25 mm). Eighteen cases were diagnosed as primary lung cancer, 3 were metastatic lung cancer, and 4 were inflammatory diseases. The average lesion size of the 10 undiagnosed cases was 12.40±5.21 mm (range, 8-24 mm). The lesion size of the undiagnosed group was significantly smaller than that of the diagnosed group (P=0.02). The average time required for the procedure was 16.78±9.57 minutes (range, 3-46 minutes), independent of the diagnosis, the lesion size, and the tumor location. We encountered one pneumothorax which required chest drainage and one hemopneumothorax which required non-elective thoracotomy and wedge resection. One patient developed high fever over 38 °C for one day following the procedure.

Conclusions

In our initial series of 35 cases, ENB-guided TBLB showed an acceptable diagnostic yield.

Bronchoscopy: Diagnostic and Therapeutic for Non-Small Cell Lung Cancer

The bronchoscope has gone through much advancement from its origin as a thin metal tube. It has become a highly sophisticated tool for clinicians. Both rigid and the flexible bronchoscopes are invaluable in the diagnosis and treatment of non-small cell lung cancer. Treatment of this disease process hinges on accurate diagnosis and lymph node staging. Technologies, such as endobronchial ultrasound, navigational bronchoscopy, and autofluorescence, have improved efficacy of endobronchial diagnosis and sample collection. If a patient is not a candidate for surgery and has a complication from a centrally located mass, the bronchoscope has been used to deliver palliative therapies.

Interventional bronchoscopy in adults

INTRODUCTION

The field of interventional pulmonology (IP) is a rapidly maturing subspecialty of pulmonary medicine, which emphasizes advanced diagnostic and therapeutic bronchoscopy for the evaluation and management of central airway obstruction, mediastinal/hilar adenopathy and lung nodules/masses, as well as minimally invasive diagnostic and therapeutic pleural procedures. Areas covered: This review describes advances in diagnostic and therapeutic bronchoscopic techniques. Expert commentary: In the past decade, there has been a remarkable growth in available technology and equipment, as well as clinical and translational research efforts focused on patient-centered outcomes. Furthermore, the recent establishment of a uniform accreditation standard for all IP fellowship programs in the United States was an important step in the continued evolution of this subspecialty of pulmonary medicine.

A prospective study on the diagnosis of peripheral lung cancer using endobronchial ultrasonography with a guide sheath and computed tomography-guided transthoracic needle aspiration

Background:

It is difficult to collect peripheral lung cancer samples. This study analyzed the applicability of endobronchial ultrasonography with a guide sheath (EBUS-GS) and computed tomography-guided transthoracic needle aspiration (CT-TTNA) for the diagnosis of peripheral lung cancer.

Methods:

A prospective analysis of peripheral lung cancer patients was performed. The study included 150 cases in the EBUS-GS group and 177 cases in the CT-TTNA group. The diagnostic rate, pathological type, genetic status and complications were analyzed.

Results:

The diagnosis rates were 64.0% and 97.7% in the EBUS-GS and CT-TTNA groups, respectively. The EBUS-GS group had undergone the most operations of the upper lobes of both lungs, while there was no significant difference in the operation distribution among the lobes in the CT-TTNA group. Adenocarcinoma (64 cases versus 51 cases) was most commonly observed in both groups, followed by squamous cell carcinoma. The detection rates of patients who were given a genetic test were 96.1% and 98.9% in the EBUS-GS and CT-TTNA groups, respectively. The incidence of complications in the EBUS-GS group was significantly less than that in the CT-TTNA group.

Conclusions:

EBUS-GS and CT-TTNA both had operational limitations. The diagnostic rate of EBUS-GS was lower than that of CT-TTNA, but there were fewer complications. CT-TTNA had better tolerance. According to the specific location of the lesion, we recommend EBUS-GS for lesions with a diameter ⩽30 mm and CT-TTNA for lesions with a diameter >30 mm. CT-TTNA specimens were advantageous for genetic testing.

State-of-the-Art Modalities for Peripheral Lung Nodule Biopsy

Lung nodules are being increasingly detected, particularly with lung cancer screening with low-dose computed tomography. Although the vast majority of lung nodules are benign, many often require tissue diagnosis. Several modalities to obtain diagnostic tissue from peripheral lung nodules are available. Bronchoscopic modalities such as radial ultrasound and electromagnetic navigational bronchoscopy are becoming increasingly used because of their superior safety profile and improving diagnostic yield. Although these modalities continue to become more advanced, newer and complementary technologies appear promising.

Advanced bronchoscopic techniques for the diagnosis of peripheral pulmonary lesions

PURPOSE OF REVIEW

The review describes recent advances in bronchoscopic modalities used to diagnose peripheral pulmonary lesions.

RECENT FINDINGS

The pooled diagnostic yield and sensitivity of radial probe endobronchial ultrasound (r-EBUS) has been reported to be 56% for lesions less than 2 cm and 78% for lesions more than 2 cm and 73%, respectively. The pooled diagnostic yield and sensitivity of electromagnetic navigational bronchoscopy (ENB) has been reported to be 65 and 71%, respectively. However, significant heterogeneity between studies was evident for both r-EBUS and ENB (sensitivity of r-EBUS: I = 75%; sensitivity of ENB: I = 57% and diagnostic yield of ENB: I = 66%). Recent studies show that these technologies do not perform in the clinical setting as well as reported in the literature. Conceptually, the domains of advanced bronchoscopic modalities that affect performance are navigation, maneuverability, and location verification. Combining technologies that deal with different domains, such as ENB (navigation) and r-EBUS (location verification), has led to synergistic effects with improved outcomes.

SUMMARY

The performance characteristics of the different advanced bronchoscopic modalities reported in the literature may not be representative of performance in clinical practice because of clinical and statistical heterogeneity in the published literature. However, evidence is accumulating that synergistic combinations of technologies may ultimately lead to better performance.

Bronchoscopy for the diagnosis of peripheral lung lesions

Peripheral pulmonary lesions (PPLs) are generally considered as lesions in the peripheral one-third of the lung although a precise definition and radiographic anatomical landmarks separating central and peripheral lesion does not yet exist. The radiographic detection of such lesions has increased significantly with the adoption of lung cancer screening programs. These lesions are not directly visible by regular flexible bronchoscopes as they are usually distal to the lobar and segmental bronchi. Traditionally, depending on location and clinical stage at presentation, these lesions were typically sampled by computerized tomography (CT) guided needle or surgical biopsy although some centers also used ultrasound and fluoroscopy guided percutaneous needle biopsy. Due to lack of direct visualization, the yield for bronchoscopic guided sampling especially of the small <2 cm pulmonary nodules was very low. Therefore, sampling has been preferentially performed by percutaneous CT guidance, which had high yield of above 90% but it comes at the cost of higher risk complications like pneumothorax with reported rate of 15% to 28%. Directly proceeding to surgical resection is also considered in appropriate candidates with high suspicion of malignancy without any evidence of distant metastasis but the proportion of such cases of lung cancer is low. The manuscript discussed the various bronchoscopic diagnostic modalities for peripheral pulmonary lesions. It is important to note that most of the studies in this field are relatively small, not randomized, suffer from selection bias, have considerable heterogeneity in sampling methodology/instruments and usually have been performed in high volume institutions by dedicated highly experienced proceduralists. The prevalence of malignancy in most of the reported cohorts has also been high which may result in higher diagnostic yields. All these factors need to be kept in mind before generalizing the results to individual centers and practices.

The introduction of electromagnetic navigation bronchoscopy for the diagnosis of small pulmonary peripheral lesions in an Asian population

Background

Electromagnetic navigation bronchoscopy (ENB) is emerging as a useful new technique for diagnosing small pulmonary peripheral lesions (SPPLs). However, the accuracy and efficiency of ENB have not been investigated in Asian populations where the differential diagnoses for SPPLs may be different. To analyze this question, this study included patients who received diagnostic ENB followed by surgery for the excision of SPPLs.

Methods

Consecutive patients referred to the Department of Thoracic Surgery, Shanghai Pulmonary Hospital (Tongji University), between May 2014 and April 2015 were recruited. ENB was used to obtain biopsy tissue and make a diagnosis, which was then confirmed by histopathological examination.

Results

The ENB was performed on 84 SPPLs of 78 patients in the study, with four patients having more than one SPPL. It successfully reached and biopsied 81 lesions. The average ENB navigation time was 10.8 minutes (range, 0.5-52 minutes). No mortality occurred, with only two complications (one bleeding and one pneumothorax). The mean diameter of the biopsied SPPLs was 19.0 mm (range, 5.0-30.0 mm). The distance from the sensor probe to the focus was 8.0 mm (range, 1-16 mm). ENB diagnosis had identical results with histopathology examination in 81 lesions (37 lung cancer and 41 non-lung cancer). The sensitivity of ENB was 92.9% (78 out of 84 lesions) in this study.

Conclusions

These data suggested that ENB was an accurate and efficient procedure to sample and diagnose SPPLs in the Asian population. It appeared that ENB had a high percentage of successful results in both navigating and aiding in the diagnosis of SPPLs in the Asian population.

Comparing Pulmonary Nodule Location During Electromagnetic Bronchoscopy With Predicted Location on the Basis of Two Virtual Airway Maps at Different Phases of Respiration

BACKGROUND

Electromagnetic navigational bronchoscopy (ENB) is guided bronchoscopy to pulmonary nodules (PN) that relies on a preprocedural chest CT to create a three-dimensional (3D) virtual airway map. The CT is traditionally done at a full inspiratory breath hold (INSP), but the procedure is performed while the patient tidal breaths, when lung volumes are closer to functional residual capacity. Movement of a PN from INSP to expiration (EXP) has been shown to average 17.6 mm. Therefore, the hypothesis of this study is that preprocedural virtual maps built off a CT closer to physiological lung volumes during bronchoscopy may better represent the actual 3D location of a PN.

METHODS

Consecutive patients with a PN needing a histological diagnosis were enrolled. A preprocedure INSP and EXP CT scan were obtained to create two virtual maps. During the airway inspection, the system tracked the sensor probe to collect 3D points that were reconstructed into the lumen registration map. This map is thought to best represent the patient's airways during bronchoscopy. Predicted PN location on an EXP and INSP map was compared with lumen registration.

RESULTS

Twenty consecutive PN underwent ENB. The predicted PN location, compared with lumen registration, was significantly closer on EXP vs INSP (4.5 mm ± 3.3 mm vs 14.8 mm ± 9.7 mm; p < 0.0001).

CONCLUSIONS

Predicted 3D nodule location using an EXP scan for ENB is significantly closer to actual nodule location when compared with an INSP scan, but whether this leads to increased yields needs to be determined.

[Application of Interventional Bronchoscopy in Pulmonary Peripheral Lesions]

肺癌是全球癌症相关死亡的主要原因, 肺癌的治愈率很低, 不仅因其自身攻击性, 还因对肺癌筛查的忽视。随着肺部筛查手段的不断进展, 肺外周病变的检出率逐渐提高, 当前对外周肺病变进行诊断的最常用方法是经支气管行支气管镜检查或计算机断层扫描(computed tomography, CT)引导下经皮穿刺针吸/活检, 然而对于外周肺病灶, 支气管镜检查有较低的诊断率, 经皮穿刺检查有较高的气胸发生率, 因此, 使用安全、微创的方法对外周肺病变进行组织确诊是临床工作者将面临的挑战。新型支气管镜介入诊断技术已逐渐用于临床, 这些技术可有效提高外周肺病变的诊断率, 缩短诊断时间, 使患者获得及时有效的治疗。本文将现有的技术进行简要综述以帮助临床医生尝试应用这些微创技术。

Improved targeting accuracy of lung tumor biopsies with scanning-beam digital x-ray tomosynthesis image guidance

PURPOSE

Electromagnetic navigation bronchoscopy (ENB) provides improved targeting accuracy during transbronchial biopsies of suspicious nodules. The greatest weakness of ENB-based guidance is the registration divergence that exists between the planning CT, acquired days or weeks before the intervention, and the patient on the table on the day of the intervention. Augmenting ENB guidance with real-time tomosynthesis imaging during the intervention could mitigate the divergence and further improve the yield of ENB-guided transbronchial biopsies. The real-time tomosynthesis prototype, the scanning-beam digital x-ray (SBDX) system, does not currently display images reconstructed by the iterative algorithm that was developed for this lung imaging application. A protocol using fiducial markers was therefore implemented to permit evaluation of potential improvements that would be provided by the SBDX system in a clinical setting.

METHODS

Ten 7 mm lesions (5 per side) were injected into the periphery of each of four preserved pig lungs. The lungs were then placed in a vacuum chamber that permitted simulation of realistic motion and deformation due to breathing. Standard clinical CT scans of the pig lung phantoms were acquired and reconstructed with isotropic resolution of 0.625 mm. Standard ENB-guided biopsy procedures including target identification, path planning, CT-to-lung registration and navigation to the lesion were carried out, and a fiducial marker was placed at the location at which a biopsy would have been acquired. The channel-to-target distance provided by the ENB system prior to fiducial placement was noted. The lung phantoms were then imaged using the SBDX system, and using high-resolution conebeam CT. The distance between the fiducial marker tip and the lesion was measured in SBDX images and in the gold-standard conebeam-CT images. The channel-to-target divergence predicted by the ENB system and measured in the SBDX images was compared to the gold standard to determine if improved targeting accuracy could be achieved using SBDX image guidance.

RESULTS

As expected, the ENB system showed poorer targeting accuracy for small peripheral nodules. Only 20 nodules of the 40 injected could be adequately reached using ENB guidance alone. The SBDX system was capable of visualizing these small lesions, and measured fiducial-to-target distances on SBDX agreed well with measurements in gold-standard conebeam-CT images (p = 0.0001). The correlation between gold-standard conebeam-CT distances and predicted fiducial-to-target distances provided by the ENB system was poor (p = 0.72), primarily due to inaccurate ENB CT-to-body registration and movement due to breathing.

CONCLUSIONS

The SBDX system permits visualization of small lung nodules, as well as accurate measurement of channel-to-target distances. Combined use of ENB with SBDX real-time image guidance could improve accuracy and yield of biopsies, particularly of those lesions located in the periphery of the lung.

Navigation bronchoscopy for diagnosis and small nodule location

Lung cancer continues to be the most common cause of cancer death. Screening programs for high risk patients with the use of low-dose computed tomography (CT) has led to the identification of small lung lesions that were difficult to identify using previous imaging modalities. Electromagnetic navigational bronchoscopy (ENB) is a novel technique that has shown to be of great utility during the evaluation of small, peripheral lesions, that would otherwise be challenging to evaluate with conventional bronchoscopy. The diagnostic yield of navigational bronchoscopy however is highly variable, with reports ranging from 59% to 94%. This variability suggests that well-defined selection criteria and standardized protocols for the use of ENB are lacking. Despite this variability, we believe that this technique is a useful tool evaluating small peripheral lung lesions when patients are properly selected.

A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): A human feasibility study

BACKGROUND

Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency.

AIMS

To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans.

METHODS

Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded.

RESULTS

Preoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered.

CONCLUSIONS

Electromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation.