Fumihiro Asano

Virtual bronchoscopic navigation combined with endobronchial ultrasound to diagnose small peripheral pulmonary lesions: a randomised trial

Background Bronchoscopy using endobronchial ultrasound (EBUS) can help to diagnose small peripheral pulmonary lesions. However, although biopsy sites can be confirmed, a bronchoscope cannot be guided in EBUS. Virtual bronchoscopic navigation (VBN) can guide a bronchoscope with virtual images, but its value has not been confirmed. Methods This prospective multicentre study examines the value of VBN-assisted EBUS for diagnosing small peripheral pulmonary lesions. 199 patients with small peripheral pulmonary lesions (diameter ≤30 mm) were randomly assigned to VBN-assisted (VBNA) or non-VBN-assisted (NVBNA) groups. A bronchoscope was introduced into the target bronchus of the VBNA group using the VBN system. Sites of specimen sampling were verified using EBUS with a guide sheath under fluoroscopy. Results The diagnostic yield was higher for the VBNA than for the NVBNA group (80.4% vs 67.0%; p=0.032). The duration of the examination and time elapsed until the start of sample collection were reduced in the VBNA compared with the NVBNA group (median (range), 24.0 (8.7–47.0) vs 26.2 (11.6–58.6) min, p=0.016) and 8.1 (2.8–39.2) vs 9.8 (2.3–42.3) min, p=0.045, respectively). The only adverse event was mild pneumothorax in a patient from the NVBNA group. Conclusions The diagnostic yield for small peripheral pulmonary lesions is increased when VBN is combined with EBUS. Clinical trial number UMIN000000569.

Transbronchial Diagnosis of A Pulmonary Peripheral Small Lesion Using an Ultrathin Bronchoscope with Virtual Bronchoscopic Navigation

Abstract:We report a patient with a pulmonary peripheral small lesion that was diagnosed using an ultrathin bronchoscope with virtual bronchoscopic (VB) navigation. In a 83-year-old man with pulmonary emphysema, chest computed tomography (CT) revealed a small lesion (18 × 14 mm) in the periphery of

Virtual Bronchoscopic Navigation Combined with Ultrathin Bronchoscopy. A Randomized Clinical Trial

RATIONALE In bronchoscopy, an ultrathin bronchoscope can be advanced to more peripheral bronchi. Because virtual bronchoscopic navigation (VBN) is a method to guide a bronchoscope under direct observation using VB images, VBN may be particularly useful when combined with ultrathin bronchoscopy. OBJECTIVES This prospective multicenter study evaluated the value of VBN-assisted ultrathin bronchoscopy for diagnosing peripheral pulmonary lesions. METHODS We randomly assigned 350 patients with peripheral pulmonary lesions (diameter, ≤30 mm) to VBN-assisted or non-VBN-assisted groups. An ultrathin bronchoscope (outer diameter, 2.8 mm) was introduced to the target bronchus using a VBN system in the VBN-assisted group, whereas only computed tomography axial images were referred to in the non-VBN-assisted group. Specimen sampling sites were verified using X-ray fluoroscopy. MEASUREMENTS AND MAIN RESULTS Subjects for analysis included 334 patients. There was no significant difference in the diagnostic yield between the VBN-assisted group (67.1%) and the non-VBN-assisted group (59.9%; P = 0.173). The subgroup analysis showed that the diagnostic yield was significantly higher in the VBN-assisted group than in the non-VBN-assisted group for right upper lobe lesions (81.3% vs. 53.2%; P = 0.004); lesions invisible on posterior-anterior radiographs (63.2% vs. 40.5%; P = 0.043); and lesions in the peripheral third of the lung field (64.7% vs. 52.1%; P = 0.047). CONCLUSIONS VBN-assisted ultrathin bronchoscopy does not improve the diagnostic yield for peripheral pulmonary lesions. However, the method improves the diagnostic yield for lesions in the subcategories (right upper lobe, invisible, peripheral third), warranting further study. Clinical trial registered with www.umin.ac.jp/ctr/ (UMIN 000001536).

Ultrathin Bronchoscopy with Multimodal Devices for Peripheral Pulmonary Lesions. A Randomized Trial

RATIONALE The combination of an ultrathin bronchoscope, navigational technology, and endobronchial ultrasound (EBUS) seems to combine the best of mutual abilities for evaluating peripheral pulmonary lesions, but ultrathin bronchoscopes that allow the use of EBUS have not been developed so far. OBJECTIVES To compare the diagnostic yield of transbronchial biopsy under EBUS, fluoroscopy, and virtual bronchoscopic navigation guidance using a novel ultrathin bronchoscope with that using a thin bronchoscope with a guide sheath for peripheral pulmonary lesions. METHODS In four centers, patients with suspected peripheral pulmonary lesions less than or equal to 30 mm in the longest diameter were included and randomized to undergo transbronchial biopsy with EBUS, fluoroscopy, and virtual bronchoscopic navigation guidance using a 3.0-mm ultrathin bronchoscope (UTB group) or a 4.0-mm thin bronchoscope with a guide sheath (TB-GS group). MEASUREMENTS AND MAIN RESULTS A total of 310 patients were enrolled and randomized, among whom 305 patients (150, UTB group; 155, TB-GS group) were analyzed. The ultrathin bronchoscope could reach more distal bronchi than the thin bronchoscope (median fifth- vs. fourth-generation bronchi; P < 0.001). Diagnostic histologic specimens were obtained in 74% (42% for benign and 81% for malignant lesions) of the UTB group and 59% (36% for benign and 70% for malignant lesions) of the TB-GS group (P = 0.044, Mantel-Haenszel test). Complications including pneumothorax, bleeding, chest pain, and pneumonia occurred in 3% and 5% in the respective groups. CONCLUSIONS The diagnostic yield of the UTB method is higher than that of the TB-GS method. Clinical trial registered with www.umin.ac.jp/ctr/ (UMIN 000003177).

Virtual Bronchoscopic Navigation Improves the Diagnostic Yield of Radial-Endobronchial Ultrasound for Peripheral Pulmonary Lesions with Involved Bronchi on CT

OBJECTIVE Bronchoscopy using radial-endobronchial ultrasound (R-EBUS) and virtual bronchoscopic navigation (VBN) is a promising method for diagnosing peripheral pulmonary lesions. We previously performed a randomized comparative trial (RCT) (i.e., VBN combined with EBUS RCT) involving patients with 30-mm or smaller peripheral pulmonary lesions and found that the addition of VBN to R-EBUS improved the diagnostic yield. In the present study, we performed a retrospective subanalysis in order to identify patients for whom VBN is useful. METHODS The per-protocol population (194 cases) of the VBN combined with EBUS RCT was divided into subgroups based on the lesion size, lung lobe containing the lesion, lesion location, presence or absence of involved bronchi (bronchus sign) on thin-section CT and whether the lesion was detected on posterior-anterior (P-A) radiographs. The difference in the diagnostic yield between the VBN-assisted (VBNA) and non-VBN-assisted (NVBNA) groups was investigated. RESULTS Within the bronchus sign-positive subgroup, the diagnostic yield in the VBNA and NVBNA groups was 94.4% (68/72) and 77.8% (56/72), respectively, showing a significantly higher yield in the VBNA group (p=0.004; odds ratio: 4.9). The yield was particularly high for lesions smaller than 20 mm (94.6% vs. 70.7%; p=0.006), lesions located in the peripheral third of the lung field (95.1% vs. 71.4%; p=0.005) and lesions invisible on P-A radiographs (90.0% vs. 41.7%; p=0.026). CONCLUSION VBN improves the diagnostic yield when combined with R-EBUS to assess lesions exhibiting involved bronchi on CT images.

A barium marking method using an ultrathin bronchoscope with virtual bronchoscopic navigation

Abstract:  CT scanning in a 77‐year‐old woman showed a ground‐glass opacity pattern shadow (9 × 7 mm) in the right lower lobe. To allow identification of the location of the lesion during thoracoscopic surgery, preoperative barium marking was performed using an ultrathin bronchoscope and virtual bronchoscopic navigation. Virtual bronchoscopy was performed based on thin‐section CT images, and virtual bronchoscopic images to the target sites were obtained. Subsequently, using virtual bronchoscopic images to right B8aiiβx, B6biiβ for navigation, an ultrathin bronchoscope was advanced to this site under direct observation. A special catheter for ultrathin bronchoscopy was advanced to sites near the lesion, and barium was infused. Barium was clearly observed by radiographic fluoroscopy during thoracoscopic surgery and was useful for determining the area for resection. Pathological examination of the resected specimen revealed atypical adenomatous hyperplasia. There were no complications with this method, and a number of target areas could be readily marked in a short time. This method may be useful before thoracoscopic surgery for small peripheral pulmonary lesions.

Does virtual bronchoscopic navigation improve the diagnostic yield of transbronchial biopsy?: Editorial

Transbronchial biopsy (TBB) is performed for diagnosis of peripheral pulmonary lesions because it is generally safe with a low incidence of complications. However, the diagnostic yield in small peripheral lesions is poor. The diagnostic sensitivity of TBB by conventional bronchoscopy for lung lesions smaller than 2 cm is approximately 34%. Virtual bronchoscopic navigation (VBN) is a method in which the bronchoscope is guided to a peripheral lung lesion under direct observation using virtual bronchoscopic images. VBN can be used for computed tomography (CT)-guided ultrathin bronchoscopy, endobronchial ultrasound using a guide sheath (EBUSGS) and conventional bronchoscopy with X-ray fluoroscopy. Previously published overall diagnostic yields using VBN and that of 2 cm or smaller lesions were 73.8% and 67.4%, respectively. These outcomes compare to a 72% diagnostic yield for use of VBN as reported by meta-analysis. The greater diagnostic yield of peripheral pulmonary lesions using bronchoscopy with VBN is therefore significant; there is no need for an expensive disposable electromagnetic sensor as is the case for electromagnetic navigation (EMN), and it can be easily performed. In a recent publication in Respirology, Kato et al. present a randomized controlled study demonstrating that VBN increases the diagnostic yield for CT-guided transbronchial biopsy (CT-TBB). The study focused on patients with CT-bronchus sign (CT-BS)-positive lesions, which were smaller than 2 cm with a low diagnostic yield on conventional bronchoscopy and located in the peripheral one-third of the lung. In this study, the use of VBN for CT-TBB significantly improved the diagnostic yield, which reached 84%. Two other randomized controlled trials of VBN have been performed. Ishida et al. reported that the diagnostic yield on bronchoscopy with EBUS-GS and X-ray fluoroscopy of 3 cm or smaller peripheral pulmonary lesions was significantly improved (from 67.0% to 80.4%) by concomitant use of VBN. In their study, both the time to the start of biopsy and the total examination time were shortened. Asano et al. reported that concomitant use of VBN in bronchoscopy of 3 cm or smaller peripheral lesions using a 2.8-mm ultrathin bronchoscope and X-ray fluoroscopy increased the diagnostic yield from 59.9% to 67.1%. However, the increase was not significant and the diagnostic yield of lesions located in the peripheral one-third of the lung was significantly improved in sub-analysis, as also reported in the current study. Therefore, VBN increases the diagnostic yield of small peripheral pulmonary lesions. A key question is with what technique should VBN be combined? There are three points to increase the diagnostic yield of TBB: navigation by bronchoscope and biopsy instrument to a lesion, confirmation of the presence of biopsy instrument at the lesion and collection of a sufficient amount of specimen using biopsy. CT-TBB is useful to confirm the presence of biopsy forceps as does EBUS. On the other hand, CT fluoroscopy presents individual axial images but location of the bronchoscope and biopsy forceps cannot be displayed on one image in real time (unlike X-ray fluoroscopy), so that the positional relationship between the bronchoscope and lesion cannot be readily identified. Moreover, frequency of CT scanning must be limited to reduce radiation exposure. Therefore, CT alone may be inappropriate for navigation. In sub-analysis of the data collected by combination with EBUS-GS, VBN significantly increased the diagnostic yield of CT-BS-positive lesions smaller than 2 cm from 70.7% to 94.6%, although these findings cannot be directly compared with that of the present study. Furthermore, Oki et al. reported that the histological yield of 3 cm or smaller peripheral lesions was 74% when radial EBUS, ultrathin bronchoscope and VBN were used together. The authors concluded that the combination of VBN and ultrathin bronchoscopy is optimal. Cone beam CT has recently been used also for bronchoscopy, and cone beam CT-TBB use may increase because of low radiation exposure and convenience of X-ray fluoroscopy. As stated by Kato et al., TBB is safe and effective when used in combination with VBN for CT-BS-positive lesions (even small lesions), but further investigations are necessary.

Reply: The Continuing Search for the Peripheral Pulmonary Nodule and Virtual Bronchoscopy

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