Endobronchial Ultrasound Probe Research Articles

Endobronchial ultrasound: a pictorial essay.

endobronchial ultrasound has gained widespread popularity in the last decade, becoming the primary technique for minimally invasive evaluation of the mediastinum and staging of lung cancer. Several tertiary and quaternary care institutes use this method, performed by trained and accredited specialists. Its main indications are (I) diagnosis and staging of lung cancer, (II) mediastinal lymphadenopathy diagnosis (III) sampling peripheral pulmonary lesions. this manuscript aims to describe the operational potential of both convex endobronchial ultrasound probe and radial endobronchial ultrasound probe technology, focusing on lung cancer. This narrative review is complemented with by the description of peculiar clinical cases in which endobronchial ultrasound played a pivotal role in reaching the diagnosis.

Predictive value of the resistance of the probe to pass through the lesion in the diagnosis of peripheral pulmonary lesions using radial probe endobronchial ultrasound with a guide sheath.

Transbronchial lung biopsy guided by radial probe endobronchial ultrasonography with a guide sheath (EBUS-GS-TBLB) is becoming a significant approach for diagnosing peripheral pulmonary lesions (PPLs). We aimed to explore the clinical value of the resistance of the probe to pass through the lesion in the diagnosis of PPLs when performing EBUS-GS-TBLB, and to determine the optimum number of EBUS-GS-TBLB. We performed a prospective, single-center study of 126 consecutive patients who underwent EBUS-GS-TBLB for solid and positive-bronchus-sign PPLs where the probe was located within the lesion from September 2019 to May 2022. The classification of probe resistance for each lesion was carried out by two bronchoscopists independently, and the final result depended on the bronchoscopist responsible for the procedures. The primary endpoint was the diagnostic yield according with the resistance pattern. The secondary endpoints were the optimum number of EBUS-GS-TBLB and factors affecting diagnostic yield. Procedural complications were also recorded. The total diagnostic yield of EBUS-GS-TBLB was 77.8%, including 83.8% malignant and 67.4% benign diseases (P=0.033). Probe resistance type II displayed the highest diagnostic yield (87.5%), followed by type III (81.0%) and type I (61.1%). A significant difference between the diagnostic yield of malignant and benign diseases was detected in type II (P = 0.008), whereas others did not. Although most of the malignant PPLs with a definitive diagnosis using EBUS-GS-TBLB in type II or type III could be diagnosed in the first biopsy, the fourth biopsy contributed the most sufficient biopsy samples. In contrast, considerably limited tissue specimens could be obtained for each biopsy in type I. The inter-observer agreement of the two blinded bronchoscopists for the classification of probe resistance was excellent (κ = 0.84). The probe resistance is a useful predictive factor for successful EBUS-GS-TBLB diagnosis of solid and positive-bronchus-sign PPLs where the probe was located within the lesion. Four serial biopsies are appropriate for both probe resistance type II and type III, and additional diagnostic procedures are needed for type I.

Safety and Feasibility of Photodynamic Therapy for Ablation of Peripheral Lung Tumors.

Newer navigational bronchoscopy technologies render peripheral lung lesions accessible for biopsy and potential treatment. We investigated whether photodynamic therapy (PDT) delivered via navigational bronchoscopy is feasible and safe for ablation of peripheral lung tumors. Two studies evaluated PDT in patients with solid peripheral lung tumors followed by clinical follow-up (nonresection study, N=5) or lobectomy (resection study, N=10). Porfimer sodium injection was administered 40 to 50 hours before navigational bronchoscopy. Lesion location was confirmed by radial probe endobronchial ultrasonography. An optical fiber diffuser was placed within or adjacent to the tumor under fluoroscopic guidance; laser light (630nm wavelength) was applied at 200J/cm of diffuser length for 500 seconds. Tumor response was assessed by modified Response Evaluation Criteria in Solid Tumors at 3 and 6 months postprocedure (nonresection study) and pathologically (resection study). There were no deaths, discontinuations for adverse events, or serious or grade ≥3 adverse events related to study treatments. Photosensitivity reactions occurred in 8 of 15 patients: 6 mild, 1 moderate, 1 severe (elevated porphyrins noted in blood after treatment). Among 5 patients with clinical follow-up, 1 had complete response, 3 had stable disease, and 1 had progressive disease at 6 months follow-up. Among 10 patients who underwent lobectomy, 1 had no evidence of tumor at resection (complete response), 3 had 40% to 50% tumor cell necrosis, 2 had 20% to 35%, and 4 had 5% to 10%. PDT for nonthermal ablation of peripheral lung tumors was feasible and safe in this small study. Further study is warranted to evaluate efficacy and corroborate the safety profile.

Virtual fluoroscopic preprocedural planning using Ziostation2 for transbronchial biopsy: A prospective self-controlled study

BackgroundBronchoscopes cannot reach the periphery of the lung because the bronchi are tapered. Therefore, selectively advancing a device—e.g., an endobronchial ultrasonography (EBUS) probe—to the targets can be challenging. Virtual fluoroscopic preprocedural planning (VFPP) is a method in which the route to the target is superimposed on an X-ray fluoroscopy-like image reconstructed from CT images, facilitating the advancement of the EBUS probe to the target. The VFPP method was integrated into the Ziostation2 bronchoscopic navigation system (Ziosoft, Inc., Tokyo, Japan) in 2018. Here, we prospectively examined the feasibility of the VFPP method using Ziostation2 (Zio-VFPP). MethodsThirty-six patients who had pulmonary lesions with long axes ≤30 mm and who underwent thin-slice CT with ≤0.625-mm thickness were enrolled. We initiated bronchoscopy using EBUS with a guide sheath (EBUS-GS) while referring to Ziostation2 bronchoscopic navigation. When the probe was not “within” a lesion, we attempted to correct its position based on Zio-VFPP. EBUS findings before and after Zio-VFPP were compared. ResultsZio-VFPP was performed in 24 patients, and EBUS findings improved in nine patients. Before Zio-VFPP, 18 patients were “outside,” but after Zio-VFPP, the number decreased to ten. Statistically, this difference was significant (p = 0.0392). There were no cases in which EBUS findings worsened with Zio-VFPP. ConclusionZio-VPFPP improves EBUS findings and significantly reduces “outside” cases. However, further investigation is necessary to verify its effectiveness.

Inheritance and innovation of the diagnosis of peripheral pulmonary lesions.

As the leading cause of cancer-related deaths worldwide, early detection and diagnosis are crucial to reduce the mortality of lung cancer. To date, the diagnosis of the peripheral pulmonary lesions (PPLs) remains a major unmet clinical need. The urgency of diagnosing PPLs has driven a series of development of the advanced bronchoscopy-guided techniques in the past decades, such as radial probe-endobronchial ultrasonography (RP-EBUS), virtual bronchoscopy navigation (VBN), electromagnetic navigation bronchoscopy (ENB), bronchoscopic transparenchymal nodule access (BTPNA), and robotic-assisted bronchoscopy. However, these techniques also have their own limitations. In this review, we would like to introduce the development of diagnostic techniques for PPLs, with a special focus on biopsy approaches and advanced guided bronchoscopy techniques by discussing their advantages, limitations, and future prospects.

Multimodal Registration for Image-Guided EBUS Bronchoscopy.

The state-of-the-art procedure for examining the lymph nodes in a lung cancer patient involves using an endobronchial ultrasound (EBUS) bronchoscope. The EBUS bronchoscope integrates two modalities into one device: (1) videobronchoscopy, which gives video images of the airway walls; and (2) convex-probe EBUS, which gives 2D fan-shaped views of extraluminal structures situated outside the airways. During the procedure, the physician first employs videobronchoscopy to navigate the device through the airways. Next, upon reaching a given node’s approximate vicinity, the physician probes the airway walls using EBUS to localize the node. Due to the fact that lymph nodes lie beyond the airways, EBUS is essential for confirming a node’s location. Unfortunately, it is well-documented that EBUS is difficult to use. In addition, while new image-guided bronchoscopy systems provide effective guidance for videobronchoscopic navigation, they offer no assistance for guiding EBUS localization. We propose a method for registering a patient’s chest CT scan to live surgical EBUS views, thereby facilitating accurate image-guided EBUS bronchoscopy. The method entails an optimization process that registers CT-based virtual EBUS views to live EBUS probe views. Results using lung cancer patient data show that the method correctly registered 28/28 (100%) lymph nodes scanned by EBUS, with a mean registration time of 3.4 s. In addition, the mean position and direction errors of registered sites were 2.2 mm and 11.8, respectively. In addition, sensitivity studies show the method’s robustness to parameter variations. Lastly, we demonstrate the method’s use in an image-guided system designed for guiding both phases of EBUS bronchoscopy.

Robotic Bronchoscopy for Peripheral Pulmonary Lesion Biopsy: Evidence-Based Review of the Two Platforms.

Despite many advancements in recent years for the sampling of peripheral pulmonary lesions, the diagnostic yield remains low. Initial excitement about the current electromagnetic navigation platforms has subsided as the real-world data shows a significantly lower diagnostic sensitivity of ~70%. “CT-to-body divergence” has been identified as a major limitation of this modality. In-tandem use of the ultrathin bronchoscope and radial endobronchial ultrasound probe has yielded only comparable results, attributable to the limited peripheral reach, device maneuverability, stability, and distractors like atelectasis. As such, experts have identified three key steps in peripheral nodule sampling—navigation (to the lesion), confirmation (of the correct location), and acquisition (tissue sampling by tools). Robotic bronchoscopy (RB) is a novel innovation that aspires to improve upon these aspects and consequently, achieve a better diagnostic yield. Through this publication, we aim to review the technical aspects, safety, feasibility, and early efficacy data for this new diagnostic modality.

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

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.

Use of Ultrathin Bronchoscope on a Need Basis Improves Diagnostic Yield of Difficult-to-Approach Pulmonary Lesions.

There are cases of peripheral lung nodules that are difficult to approach despite using ancillary diagnostic devices during multimodal bronchoscopy. The use of ultrathin bronchoscopes has shown superiority over standard thin bronchoscopes. We retrospectively evaluated whether substitution of the thin-bronchoscope by the ultrathin device during multimodal bronchoscopy improves lesion ultrasound visualization and diagnostic yield in patients with difficult-to-approach pulmonary lesions. The study comprised 44 out of 338 patients that underwent multimodal bronchoscopy at Matsusaka Municipal Hospital. The thin-bronchoscope with an external diameter of 4 mm was substituted by the ultrathin-bronchoscope with an external diameter of 3 mm when the radial endobronchial ultrasound showed that the probe position was not within the target lesion. The median diameter of the pulmonary tumors was 17.5 mm (range: 6.0–5.2.0 mm). The endobronchial ultrasound showed the probe's position adjacent to the lesion in 12 cases and no visible lesion in 32 cases using a thin-bronchoscope. However, the endobronchial ultrasound views changed from adjacent to the lesion to within the lesion in nine cases, from no visible lesion to within the lesion in 17 cases, and from no visible lesion to adjacent to the lesion in nine cases after bronchoscope substitution. After substitution, the diagnostic yield was 80.8% in cases with the radial probe within the target lesion, 72.7% in cases with the probe adjacent to the target lesion, and 0% in cases with no visible lesion. The overall diagnostic yield was 65.9% after bronchoscope substitution. The substitution of the thin bronchoscope by the ultrathin device on a need basis improves the position of the radial endobronchial ultrasound probe and diagnostic yield of pulmonary lesions during multimodal diagnostic bronchoscopy.

Diagnostic value of radial endobronchial ultrasonographic features in predominant solid peripheral pulmonary lesions.

BackgroundTransbronchial lung biopsy (TBLB) of peripheral pulmonary lesions (PPLs) is usually performed for a definite diagnosis. Radial probe endobronchial ultrasonography is often acknowledged as a good guidance method for TBLB as it can help physicians confirm the lesions’ position. It is also a non-invasive imaging diagnostic method. This clinical study was designed to evaluate the ability of radial endobronchial ultrasonography (R-EBUS) to differentiate benign from malignant predominant solid PPLs based on imaging features.MethodsPatients with predominant solid PPLs were enrolled in this study retrospectively. TBLB was performed using R-EBUS with or without other guidance techniques. One typical sonographic image and one video of each lesion were recorded for analysis. Six radial probe endobronchial ultrasonographic image features (size, shape, echogenicity, margin, blood vessel, and linear-discrete air bronchogram) were studied by ultrasonography specialists and physicians who were blinded to the final diagnosis. The sum score model of the combined predictive factors indicated the best diagnostic accuracies for predicting malignant PPLs. The model group results were used to establish the diagnostic standard for a verification group.ResultsA total of 303 patients were enrolled in the model group from July 2018 to July 2019 at the Shanghai Chest Hospital (214 with malignant and 89 with benign lesions). The mean lesion long axis on computed tomographic images was 34.39±13.79 mm. There were significant statistical differences between benign and malignant lesions in the long axis, short axis, shape, margin, blood vessel, and linear-discrete air bronchogram assessed by radial endobronchial ultrasound. Long axis, lobulation, distinct but not sharp margin, absence of blood vessel, and absence of linear-discrete air bronchogram were good predictive factors of malignant lesions. A sum score model value of 79.54% of these combined factors indicated the best diagnostic accuracy for predicting malignant lesions. Eighty-seven patients were enrolled in the verification group from August to October 2019. The sum score model showed a diagnostic accuracy of 82.76%.ConclusionsRadial endobronchial ultrasonographic features can differentiate malignant from benign lesions and thus have potential diagnosis value in predominant solid PPLs.

The value of virtual bronchoscopic navigation and radial endobronchial ultrasound-guided transbronchial lung cryobiopsies for pulmonary lymphangitic carcinomatosis.

BackgroundPulmonary lymphangitic carcinomatosis (PLC) is characterized by malignant infiltration into lung lymphatic channels from a primary site and is often observed in advanced malignant tumors. This study aimed to evaluate the diagnostic yield of transbronchial lung cryobiopsy in PLC guided by radial endobronchial ultrasound and virtual bronchoscopic navigation (VBN).MethodsThis prospective study enrolled 40 patients with clinical and radiologic features indicating PLC. The radial endobronchial ultrasound probe was initially advanced to the region of interest of the desired lobe near the pleura with guidance by VBN. Transbronchial lung biopsy and transbronchial lung cryobiopsy were both performed in the same ROI of all patients with the obtained samples being sent to the pathology laboratory for diagnostic analysis. Procedural complications were recorded.ResultsThe average number of transbronchial lung biopsy and transbronchial lung cryobiopsy specimens were 4 (3 to 6) and 2 (1 to 3), respectively (t=10.43, P<0.01), with the corresponding mean diameters per biopsy being 3.7 and 8.7 mm (t=12.37, P<0.01). The diagnostic yields of transbronchial lung biopsy and transbronchial lung cryobiopsy were 70% (28/40) and 92.5% (37/40), respectively. The final positive predictive values of transbronchial lung cryobiopsy and transbronchial lung biopsy for PLC were 94.4% (34/36) and 77.8% (28/36), respectively (χ2=23.94, P<0.01). Further, 52.2% (12/23) and 81.5% (22/27) of the patients in the transbronchial lung biopsy and transbronchial lung cryobiopsy groups, respectively, were diagnosed with non-small lung cancer after further molecular analysis (χ2=19.56, P<0.01). Only 2 (5%) cases presented postoperative pneumothorax. Moreover, 0 (0%), 3 (7.5%), and 17 (42.5%) patients presented severe, moderate, and mild bleeding, respectively. There were no other adverse events or deaths.ConclusionsTransbronchial lung cryobiopsy with the guidance of radial endobronchial ultrasound and VBN without fluoroscopy has a good diagnostic yield for PLC; moreover, it allows one to obtain adequate and intact tissue samples for further molecular analysis.

RP EBUS as a guide for transbronchial pulmonary biopsy in the diagnosis of organizing pneumonia.

Diffuse parenchymal lung diseases (DPLDs) include a wide variety of manifestations characterized by different degrees of inflammation and fibrosis with various patterns of secondary lobule alterations, such that the diagnosis often requires histopathological confirmation in addition to clinical and radiological data. Radial probe endobronchial ultrasonography (RP EBUS) can be used as a guide for transbronchial pulmonary biopsy (TBPB) to obtain tissue samples, and thus can be a useful tool in the diagnostic management of peripheral pulmonary lesions. Organizing pneumonia (OP) is a particular type of DPLD characterized by lung inflammation and scarring that obstruct the small airways and air sacs of the lung. In this study, we describe how and when RP EBUS can be used to guide TBPB and significantly help in the diagnosis of OP.

A novel biosimulator based on ex vivo porcine lungs for training in peripheral tissue sampling using endobronchial ultrasonography with a guide sheath.

Although radial probe endobronchial ultrasonography (EBUS) with a guide sheath (GS; EBUS-GS) is widely used for sampling peripheral pulmonary lesions (PPLs), a standard training model for EBUS-GS remains to be developed. The purpose of this study was to evaluate the feasibility of a novel pulmonary biosimulator for hands-on training in peripheral tissue sampling using EBUS-GS. We established a novel biosimulator for EBUS-GS using porcine lungs. The simulator was equipped with multiple pseudo PPLs that were created using blue agar solution injected through GS inserted in a bronchoscope. A total of 12 voluntary trainees participated in a hands-on training course using the biosimulator. The size of samples acquired using biopsy forceps were compared between initial and post-training biopsies, and trainee satisfaction with the biosimulator and training program were evaluated using a questionnaire. Under the guidance of a trainer, all trainees successfully detected pseudo PPLs using radial probe EBUS before the initial biopsy, and 11 trainees acquired samples from the target lesions during the initial biopsy. Post-training biopsy samples were larger than the initial samples for eight trainees. The results of the questionnaire revealed that all trainees were satisfied with the biosimulator. Moreover, eight trainees who had previously participated in another hands-on EBUS-GS training program involving a synthetic phantom model showed greater satisfaction for the biosimulator. A hands-on training program using the novel biosimulator assessed in this study could aid clinicians in improving their skills for EBUS-GS and acquiring larger peripheral tissue samples using biopsy forceps inserted through GS.

ES07.03 Radial Endosonography

Flexible bronchoscopy, with its attendant procedures, is a valuable tool for diagnosis and staging of patients with suspected lung cancer. The development of endobronchial ultrasound (EBUS) has extended the view of the bronchoscopist beyond the bronchial wall. Two types of EBUS exist. The curved linear (convex) probe EBUS and the radial probe EBUS. The convex ultrasound transducer is located at the tip of a flexible bronchoscope (linear scanning EBUS) and allows real-time sampling. This technique is mainly used for mediastinal nodal staging and assessment of centrally located lung tumours when lung cancer is known or suspected. The radial EBUS probe houses a rotating ultrasound transducer at the distal end which produces a high-resolution radial (360˚) ultrasound image of the airway wall and surrounding structures. This probe is inserted through the biopsy channel of a standard bronchoscope. In a lung cancer setting, this technique is used for evaluation of the depth of tumour invasion in the central airways enabling differentiation between early and invasive lung cancer and detection of peripheral pulmonary lesions (PPLs). Radial EBUS does not permit sampling in real-time such that sequential sampling with separate equipment is necessary. The current focus of this abstract is the role of radial EBUS for PPLs. With the increased use of chest CT-scans, the frequency of incidentally found PPLs has increased as well. Guidelines advise to evaluate and manage individuals with pulmonary nodules by estimating the probability of malignancy. The goal is to diagnose a malignancy promptly for timely treatment and to avoid invasive procedures and surgery in patients with benign lesions. Approaches to establish a tissue diagnosis include imaging-guided transthoracic and bronchoscopic sampling techniques. The sensitivity of traditional flexible bronchoscopy – with or without fluoroscopic guidance – for peripheral lesions in patients suspected of having lung cancer is suboptimal and is affected most by the size of the lesion (<2cm 34%; >2cm 63%).(1) For PPLs, the sensitivity of transthoracic needle aspiration (TTNA) is greater than that of bronchoscopy. In this setting, TTNA has an approximately 90% chance of providing confirmation of a diagnosis. However, CT-guided percutaneous TTNA has a considerable risk of pneumothorax.(1) This has led to the development of new modalities as radial EBUS, virtual bronchoscopy, electromagnetic navigation bronchoscopy and ultrathin bronchoscopes. In 2002, radial EBUS was first used to guide transbronchial lung biopsy (TBLB).(2) Numerous papers has been published since, reporting varying diagnostic performances of radial EBUS. Three systematic reviews and meta-analyses report a sensitivity of radial EBUS for diagnosis of peripheral lesions of 70% to 73%. Although there is considerable heterogeneity in lesion size, prevalence of malignancy, variable use of additional image guiding technology and reference standard in included studies.(3-5) The diagnostic yield of radial EBUS is significantly higher for lesion > 2 cm in size, malignant in nature and those associated with a bronchus sign on CT scan.(3-5) The diagnostic yield is also higher when the radial EBUS probe is in the center of the lesion opposed to being adjacent to it.(3) The diagnostic yield of radial EBUS does not exceed CT-guided percutaneous needle biopsy / aspiration. The major advantage of radial EBUS over a transthoracic approach is its safety profile (overall pneumothorax rate of just 1.0%)(4) and the ability to combine with staging procedures. In conclusion, to diagnose PPLs (not visible by bronchoscopy) radial EBUS is a safe and has a reasonably high diagnostic yield. Main limitations of the technique include operator dependence and the need for sequential sampling as radial EBUS does not allow real-time sampling. 1. Rivera MP, Mehta AC, Wahidi MM. Establishing the diagnosis of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013;143(5 Suppl):e142S-e65S. 2. Herth FJ, Ernst A, Becker HD. Endobronchial ultrasound-guided transbronchial lung biopsy in solitary pulmonary nodules and peripheral lesions. The European respiratory journal. 2002;20(4):972- 3. Ali MS, Trick W, Mba BI, Mohananey D, Sethi J, Musani AI. Radial endobronchial ultrasound for the diagnosis of peripheral pulmonary lesions: A systematic review and meta-analysis. Respirology (Carlton, Vic). 2017;22(3):443-53. 4. Steinfort DP, Khor YH, Manser RL, Irving LB. Radial probe endobronchial ultrasound for the diagnosis of peripheral lung cancer: systematic review and meta-analysis. The European respiratory journal. 2011;37(4):902-10. 5. Wang Memoli JS, Nietert PJ, Silvestri GA. Meta-analysis of guided bronchoscopy for the evaluation of the pulmonary nodule. Chest. 2012;142(2):385-93. Radial endosonography, diagnosis, lung cancer

Diagnostic Yield of the Virtual Bronchoscopic Navigation System Guided Sampling of Peripheral Lung Lesions using Ultrathin Bronchoscope and Protected Bronchial Brush.

The use of an ultrathin bronchoscope (UB) to diagnose peripheral pulmonary lesions is described. A virtual bronchoscopic navigation system was used to direct the ultrathin scope to the nodule. One of the constraints of this technique was the inability to confirm the target lesion position during biopsy by using a conventional linear endobronchial ultrasound probe, since the probe does not fit into a 1.2 mm working channel of this bronchoscope. The aim of the study was to review our institutional experience with the use of a UB for sampling peripheral pulmonary lesions using the transbronchial brush guided by virtual bronchoscopy. We describe a technique wherein we attempt to brush all the visible bronchial sub-segments once the bronchoscope has reached close to the nodule. In total, 52 patients underwent the procedure between 2010 and 2017. A multiplanar computed tomography (CT) scan of the chest was obtained and subsequently uploaded to the Lung Point Virtual bronchoscopy navigation software. The UB was parked close to the lesion. All visible airway branches were then brushed using a protected bronchial brush. The data were retrospectively abstracted from the electronic medical records using standardized forms. A total of 52 lesions (40 solid, 8 part-solid, 3 cavitary, and 1 ground-glass) were sampled using a transbronchial brush (median, 2; range, 1-8). Twenty-four lesions were under 2 cm in size. The overall success rates were 67.3%. The average diameter of nodules was 2.7±1.01 cm; 65% lesions were in the outer-third of the lungs. The cancer-specific sensitivity was 72.5%. The presence of bronchus sign; location of the lesion; and the characteristics, size, and stage of cancer did not have any impact on the diagnostic yield. Virtual bronchoscopy-guided ultrathin bronchoscopy with bronchial brushing is safe and has a diagnostic yield comparable to other described techniques for evaluating peripheral pulmonary nodules.

Competence in endosonographic techniques.

Endobronchial ultrasound (EBUS) has revolutionized the field of bronchoscopy because it allows to observe peribronchial structures and distal peripheral lung lesions. The use of EBUS was first described by Hurte and Hanrath in 1992. EBUS technology exists in two forms: radial and convex transducer probes. The radial EBUS probe has a 20-MHZ (12-30 MHz available) rotating transducer that can be inserted together with or without a guide sheath through the working channel (2.0-2.8 mm) of a standard flexible bronchoscope. The transducer rotates and produces a 360-degree circular image around the central position of the probe. There are two types of radial EBUS probes: "peripheral" probes, used to identify parenchymal lung lesions, and "central" probes, with balloon sheaths, used for the assessment of airway walls and peribronchial lymph nodes.

Endobronchial treatment of peripheral tumors: ongoing development and perspectives.

The expanded possibilities to explore the lung deeper with new tools such as electromagnetic navigation bronchoscopy (ENB) or radial probe endobronchial ultrasonography (radial EBUS), combined with miniaturization of traditional local therapies such as radiofrequency ablation (RFA), radiotherapy, cryotherapy or photodynamic therapy, let the bronchoscopists hope for new ways of endoscopic treatments. This challenge could change the practice in the upcoming decades but raise some physical and technical issues. Safety and efficacy need to be solidly established to face the serious concurrence of stereotactic radiotherapy (SBRT) or percutaneous RFA. Here we describe ongoing development and perspectives for endobronchial treatment of peripheral lung tumors.

Diagnostic Utility of Electromagnetic Navigation Bronchoscopy Combined with Radial Probe Endobronchial Ultrasound in Peripheral Pulmonary Lesions

背景与目的随着高分辨计算机断层扫描（computed tomography, CT）的广泛应用和健康体检的普遍开展，大量周围型肺部病灶被发现，对临床诊断治疗提出了新的挑战。电磁导航支气管镜（electromagnetic navigation bronchoscope, ENB）和径向探头支气管内超声（radial probe bronchoscopy ultrasound, R-EBUS）是用于周围型肺部病灶诊断的新兴技术，本研究旨在探讨ENB联合R-EBUS对肺周围型病灶诊断中的应用价值。方法2016年9月-2017年11月苏州大学附属第一医院胸外科应用ENB技术对18例患者的30处肺部周围型病灶进行了检查，术前制定导航计划，术中导航成功到达预定位置后使用R-EBUS确认病灶，依次使用穿刺针、细胞刷、活检钳进行病灶组织活检。结果30处肺部周围型病灶，导航成功率为100%（30/30），阳性诊断率为90%（27/30）。手术时间为（95.61±28.74）min，每处病灶导航时间为（25.90±11.29）min，发生气胸1例，未见其他严重并发症。结论利用ENB联合R-EBUS技术诊断肺周围型病灶具有较高的导航成功率和诊断阳性率，安全有效，值得进行临床推广。

Experience improves the performance of endobronchial ultrasound-guided transbronchial biopsy for peripheral pulmonary lesions: A learning curve at a medical centre.

BackgroundEndobronchial ultrasound(EBUS)-guided transbronchial biopsy(TBB) is the preferred diagnostic tool for peripheral pulmonary lesions(PPLs) and mastering this procedure is an important task in the training of chest physicians. Little has been published about the learning experience of physicians with this technique, particularly at an institutional level. We aimed to establish a learning curve for EBUS-guided TBB for PPLs at a medical center.MethodsBetween 2008 and 2015, consecutive patients with PPLs referred for EBUS-guided TBB at National Taiwan University Hospital were enrolled. To build the learning curve, the diagnostic yield of TBB (plus brushings and washings) was calculated and compared. Meanwhile, lesion characteristics, and procedure-related features and complications were obtained to analyze associations with TBB yield and safety profile.ResultsA total of 2144 patients were included and EBUS-guided TBB was diagnostic for 1547(72%). The TBB yield was 64% in 2008 and reached a plateau of 72% after 2010. It took approximately 400 EBUS-guided procedures to achieve stable proficiency. Further analysis showed that improvement in diagnostic yield over time was mainly observed in PPLs, in cases in which the diameter was ≤2 cm or the EBUS probe could not be positioned within. Complication rates were low, with 1.8% and 0.5% for pneumothorax and hemorrhage, respectively.ConclusionsEven though EBUS-guided TBB is an easy-to-learn technique, it takes 3 years or around 400 procedures for a medical center to achieve a better and stable performance. In particular, the diagnostic yield for lesions without the probe within or those sized ≤2 cm could improve with time.

Radial Endobronchial Ultrasound (EBUS) Guided Suction Catheter-Biopsy in Histological Diagnosis of Peripheral Pulmonary Lesions.

Background: EBUS guided trans-bronchial biopsy became routine in diagnosis of peripheral pulmonary lesions (PPL). Suction catheter-biopsy is a technique for obtaining a tissue sample from peripheral lung parenchyma. Aim of this study was to evaluate diagnostic efficiency, feasibility and safety of EBUS guided suction catheter-biopsy (SCB) in comparison to trans-bronchial biopsy (TBB) in diagnosis of PPL. The main intention was to demonstrate non-inferiority of the technique over trans-bronchial biopsy, especially when used under navigation of the EBUS.Methods: Radial EBUS probe (UM-3R, Olympus Co, Japan.) without guiding sheath was used to navigate suction catheter and TBB forceps to the PPL. The catheter was connected to the collection canister via vacuum pump. The SCB specimens were fixed with 10% buffered formalin.Results: There were 168 patients enrolled in this study; 69.9% males and 30.1% females. Main lesion diameter was 4.1±1.9 cm. Majority of patients, 131(77.9%) were diagnosed with lung cancer. Per-biopsy calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for EBUS-SCB were 92.4%, 100%, 100% and 67.7%, respectively. Corresponding values for EBUS-TBB were 92.3%, 100%, 100% and 69.7%. Only the size of the lesion significantly influenced (p=0.005) diagnostic performance. Complications occurred in 2 patients; one pneumothorax and one excessive bleeding.Conclusion: EBUS guided SCB is efficient, feasible and safe in diagnosis of peripheral lung cancer. The technique is complementary to trans-bronchial biopsy.