Clinical application of optical and electromagnetic navigation system in CT-guided radiofrequency ablation of lung metastases

PURPOSE

To evaluate the clinical value of CT-guided radiofrequency ablation (RFA) in the diagnosis and treatment of pulmonary metastases under optical and electromagnetic navigation.

METHODS

Data on CT-guided radiofrequency ablation treatment of 93 metastatic lung lesions in 70 patients were retrospectively analyzed. There were 46 males and 24 females with a median age of 60.0 years (16-85 years). All lesions were ≤3cm in diameter. 57 patients were treated with 17 G radiofrequency ablation needle puncture directly ablated the lesion without biopsy, and 13 patients were treated with 16 G coaxial needle biopsy followed by radiofrequency ablation. There were 25 cases in the optical navigation group, 25 in the electromagnetic navigation group, and 20 in the non-navigation group. The navigation group was performed by primary interventionalists with less than 5 years of experience, and the non-navigation group was performed by interventionalists with more than 5 years of experience.

RESULT

All operations were successfully performed. There was no statistically significant difference in the overall distribution of follow-up results among the optical, electromagnetic, and no navigation groups. Complete ablation was achieved in 84 lesions (90.3%). 7 lesions showed incomplete ablation and were completely inactivated after repeat ablation. 2 lesions progressed locally, and one of them still had an increasing trend after repeat ablation. No serious complications occurred after the operation.

CONCLUSIONS

Treatment with optical and electromagnetic navigation systems by less experienced operators has similar outcomes to traditional treatments without navigational systems performed by more experienced operators.

Design and Simulate Intracranial Support to Guide Maxillo Surgery: A Study Based on Bioengineering

BACKGROUND

Intraoperative navigation allows for the creation of a real-time relationship between the anatomy imagined during diagnosis/planning and the site of surgical interest. This procedure takes place by identifying and registering trustworthy anatomical markers on planning images and using a point locator during the operation. The locator is calibrated in the workspace by placing a Dynamic Reference Frame (DRF) sensor.

OBJECTIVE

This study aims to calculate the localization accuracy of an electromagnetic locator of neuro-maxillofacial surgery, moving the standard sensor position to a different position more suitable for maxillofacial surgery.

MATERIALS AND METHODS

The upper dental arch was chosen as an alternative fixed point for the positioning of the sensor. The prototype of a bite support device was designed and generated via 3D printing. CT images of a skull phantom with 10 anatomical landmarks were acquired. The testing procedure consisted of 10 measurements for each position of the sensor: precisely 10 measurements with the sensor placed on the forehead and 10 measurements with the sensor placed on the bite support device. It also evaluated the localization error by comparing the two procedures.

RESULTS

The localization error, when the sensor was placed on the bite support device, was lower in the sphere located on the temporal bone. It was the same in the spheres located on the maxillary bone. The test analysis of the data of the new device showed that it is reliable; the tests are reproducible and can be considered as accurate as the traditional ones. In addition, the sensor mounted on this device has proven to be slightly superior in terms of accuracy and accuracy in areas such as the middle third of the face and jaw.

DISCUSSION AND CONCLUSION

The realization of the bite support device allowed the sensor to change position concerning its natural site. This procedure allows us to explore structures, such as the frontal site, which were initially difficult to approach with neuronavigation and improves the approach to midface structures, already studied with neuronavigation. The new calibration, with the position of the sensor on the support device in the same reference points sphere, highlighted the reduction in the location error. We can say that the support proposed in this study lays the foundations for a new navigation approach for patients in maxillofacial surgery, by changing the position of the sensor. It has strong points in improving the localization error for some reference points without determining disadvantages both in the calibration and in the surgical impediment.

A Multicenter, Single-Arm, Prospective Trial Assessing the Diagnostic Yield of Electromagnetic Bronchoscopic and Transthoracic Navigation for Peripheral Pulmonary Nodules

Rationale: Strict adherence to procedural protocols and diagnostic definitions is critical to understand the efficacy of new technologies. Electromagnetic navigational bronchoscopy (ENB) for lung nodule biopsy has been used for decades without a solid understanding of its efficacy, but offers the opportunity for simultaneous tissue acquisition via electromagnetic navigational transthoracic biopsy (EMN-TTNA) and staging via endobronchial ultrasound (EBUS). Objective: To evaluate the diagnostic yield of EBUS, ENB, and EMN-TTNA during a single procedure using a strict a priori definition of diagnostic yield with central pathology adjudication. Methods: A prospective, single-arm trial was conducted at eight centers enrolling participants with pulmonary nodules (<3 cm; without computed tomography [CT]- and/or positron emission tomography-positive mediastinal lymph nodes) who underwent a staged procedure with same-day CT, EBUS, ENB, and EMN-TTNA. The procedure was staged such that, when a diagnosis had been achieved via rapid on-site pathologic evaluation, the procedure was ended and subsequent biopsy modalities were not attempted. A study finding was diagnostic if an independent pathology core laboratory confirmed malignancy or a definitive benign finding. The primary endpoint was the diagnostic yield of the combination of CT, EBUS, ENB, and EMN-TTNA. Measurements and Main Results: A total of 160 participants at 8 centers with a mean nodule size of 18 ± 6 mm were enrolled. The diagnostic yield of the combined procedure was 59% (94 of 160; 95% confidence interval [CI], 51-66%). Nodule regression was found on same-day CT in 2.5% of cases (4 of 160; 95% CI, 0.69-6.3%), and EBUS confirmed malignancy in 7.1% of cases (11 of 156; 95% CI, 3.6-12%). The yield of ENB alone was 49% (74 of 150; 95% CI, 41-58%), that of EMN-TTNA alone was 27% (8 of 30; 95% CI, 12-46%), and that of ENB plus EMN-TTNA was 53% (79 of 150; 95% CI, 44-61%). Complications included a pneumothorax rate of 10% and a 2% bleeding rate. When EMN-TTNA was performed, the pneumothorax rate was 30%. Conclusions: The diagnostic yield for ENB is 49%, which increases to 59% with the addition of same-day CT, EBUS, and EMN-TTNA, lower than in prior reports in the literature. The high complication rate and low diagnostic yield of EMN-TTNA does not support its routine use. Clinical trial registered with www.clinicaltrials.gov (NCT03338049).

Utility of multimodal sampling and testing during advanced bronchoscopy for diagnosing atypical respiratory infections in a Coccidioides-endemic region

Background

The role of advanced diagnostic bronchoscopy (ADB) for assessing atypical respiratory infections is unclear. The purpose of this study was to ascertain: (I) the diagnostic utility of ADB-tissue sampling in patients with focal thoracic lesions due to atypical respiratory infections; (II) how multimodal bronchoscopic sampling and testing enhance diagnosis in a Coccidioides-endemic region.

Methods

A retrospective observational cohort study analyzing all ADBs performed over a 10-year period in patients with focal thoracic lesions diagnosed with a non-malignant disorder. Only cases which procured lower respiratory tract secretion and tissue samples by ADB, and had both cytohistology and culture results available were included.

Results

Among 403 subjects with non-malignant disease, 136 (33.7%) were diagnosed with atypical respiratory infections, with ADB contributing a diagnosis in 119 (87.5%) of these. Coccidioidal disease was independently associated with a cytohistologic diagnosis [odds ratio =7.64, 95% confidence interval (CI): 2.51-23.26; P<0.001]. Mycobacteria were more effectively identified by culture (overall yield of 8.4%, vs. 2.7% by cytohistology; P<0.001). Among subjects for which both respiratory secretion and tissue sampling were dual-tested with culture and cytology/cytohistology, adding ADB-guided transbronchial needle aspiration and/or forceps biopsy (TBNA/TBFB) to bronchoalveolar lavage and/or bronchial washings (BAL/BW) more than doubled the yield for dimorphic fungi, from 7.1% to 15.1% (increase of 8.0%, 95% CI: 5.2-11.9%). For lung lesions, adding tissue culture to dual TBNA/TBFB cytohistology-tested lung samples doubled the proportion diagnosed with atypical infection over using TBNA-cytohistology alone (increase of 15.8%, 95% CI: 10.4-23.1%). Adding lymph node to lung sampling increased the proportion diagnosed with coccidioidomycosis by 8.8% (95% CI: 4.8-15%). Among subjects with atypical respiratory infections, major ADB-related complications occurred in 1.5%.

Conclusions

ADB is useful for diagnosing atypical respiratory infections manifesting as focal thoracic lesions. A multimodal approach to both sampling and testing enhances yield, while maintaining a favorable procedure safety profile. Cytohistology testing and nodal sampling are beneficial for pulmonary coccidioidomycosis, and culture for mycobacterial disease. The approach to ADB-sampling should be adjusted according to clinical context and regional infection patterns.

Identification of the intersegmental plane via electromagnetic navigation for anatomical segmentectomy

Accurate identification of the physiological intersegmental plane is crucial for successful anatomical segmentectomy. Current techniques, such as the inflation-deflation method, may result in uncertain cutting lines, leading to unsuitable resection extents. Here, we demonstrated the successful use of electromagnetic navigation with methylene blue dye-marking to preoperatively and precisely identify the physiological intersegmental plane in two patients with small-sized peripheral non-small cell lung cancer (NSCLC). This novel technique offers the potential for precise cutting lines that align closely with the physiological intersegmental plane, thus improving the accuracy and efficacy of anatomical segmentectomy for these selected NSCLC patients.

Navigation guidance in neuroendoscopic management of complex hydrocephalus

Patients with multiloculated hydrocephalus have multiple, separate abnormal CSF collections with no communication between them. Causes include complications of neonatal meningitis, germinal matrix hemorrhage in neonates, head trauma, and intracranial surgery. Endoscopic fenestration with shunt insertion is a safe and less invasive technique as the initial treatment. In this video, the authors demonstrate a few cases in which electromagnetic navigation was used with a stylet inserted through the operating endoscope to guide the surgeon. Modalities such as insertion of intraventricular contrast and fluorescein may be used as adjuvants, as demonstrated. The use of navigation helps to identify distorted anatomical landmarks and guides surgery. The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22152.

[A Novel Robotic Bronchoscopic Surgical System]

Transbronchil biopsy has the characteristic of less trauma and quick recovery compared to percutaneous aspiration biopsy. In order to automate this procedure, it requires the development of a robotic surgical system that combines electromagnetic navigation and flexible endoscope. The robotic surgical system introduced herein consists of flexible endoscope, remote-control handle, electromagnetic navigation and dexterous manipulators. The robotic system supports lung bronchial model segmentation and reconstruction, automatic bronchial path planning, real-time navigation and visual biopsy. In the control of the endoscopic catheter, an elasticity compensation algorithm was proposed to improve the location accuracy of the catheter and operational efficiency. Clinical trials proved that the robotic system had high positioning accuracy, was intuitive to operate, and could improve the biopsy efficiency, shorten the learning time, reduce the burden of surgical operations, and lower radiation exposure and infection rate.

[Research on the Application of Electromagnetic Navigation Technology in Surgical Robots]

Due to the need to achieve precise operations during surgery, in order to prevent hand tremors and poor surgical field of view, more and more surgical robots are used in surgical operations combined with navigation technology to meet the requirements for surgical accuracy. Open surgery such as orthopaedics, joint replacement and neurosurgery on the market generally use optical navigation systems to guide robots to achieve precise positioning, but optical navigation systems cannot be used for operations in areas with small surgical space. Therefore, a robotic surgical system based on electromagnetic navigation technology that can be applied to the craniofacial area was proposed. By using this robot, the problems of difficult operation and low precision caused by the narrow craniofacial space can be solved. Key techniques and considerations are studied. The function of the developed prototype is verified through model tests. The test results show that the surgical robot under the electromagnetic navigation technology can achieve precise surgical operations improve the success rate of the doctor's surgery and reduce postoperative complications.

Clinical value of an electromagnetic navigation system for CT-guided percutaneous lung biopsy of peripheral lung lesions

Background

The purpose of this study was to retrospectively evaluate the clinical value of an electromagnetic navigation system for CT-guided percutaneous lung biopsy of peripheral lung lesions.

Methods

This was a retrospective study. Patients with peripheral lung lesions in our institution between January 2019 and December 2020, who underwent lung biopsy assisted by the electromagnetic navigation system were included in Group A, and those who underwent lung biopsy using conventional CT-guided percutaneous lung biopsy were included in Group B. The general features and clinical and technical information of each patient were collected and evaluated in both groups.

Results

A total of 141 patients were included in Group A (78 males and 63 females; median age, 65 years; range, 32–79 years), and 96 patients were included in group B (57 males and 39 females; median age, 65 years; range, 34–80 years). The technical success rate was 100% in both groups. The technical efficacy rate was 92.9% and 90.6% in Groups A and B (P=0.525), respectively. There was no significant difference in surgical time and the number of CT scans between the two groups, and only grade 1–2 complications occurred in the patients.

Conclusions

The electromagnetic navigation system is an effective and safe auxiliary tool for CT-guided percutaneous lung biopsy of peripheral lung lesions.

Novel use of electromagnetic navigation for thoracostomy tube placement

Management of recurrent pleural effusions can be challenging and may require multiple modalities for treatment. Advanced image guidance with ultrasound or computed tomography is often useful for increased accuracy. We demonstrate a novel application of a percutaneous image-guided technique using electromagnetic navigation to successfully place thoracostomy tubes.

Optimizing Diagnostic and Staging Pathways for Suspected Lung Cancer: A Decision Analysis

BACKGROUND

The optimal diagnostic and staging strategy for patients with suspected lung cancer is not known.

RESEARCH QUESTION

What diagnostic and staging strategies are most cost-effective for lung cancer?

STUDY DESIGN AND METHODS

A decision model was developed by using a hypothetical patient with a high probability of lung cancer. Sixteen unique permutations of bronchoscopy with fluoroscopy, radial endobronchial ultrasound, electromagnetic navigation, convex endobronchial ultrasound with or without rapid-onsite evaluation (ROSE), CT-guided biopsy (CTBx), and surgery were evaluated. Outcomes included cost, complications, mortality, time to complete the evaluation, rate of undetected N2-3 disease at surgery, incremental cost-complication ratio, and willingness-to-pay thresholds. Sensitivity analyses were performed on primary outcomes.

RESULTS

For a peripheral lung lesion and radiographic N0 disease, the best bronchoscopy strategy costs $1,694 more than the best CTBx strategy but resulted in fewer complications (risk difference, 14%). The additional cost of bronchoscopy to avoid one complication from a CTBx strategy was $12,037. The cost and cumulative complications of bronchoscopy strategies increased compared with CTBx strategies for small lesions. The cost and cumulative complications of bronchoscopy strategies decreased compared with CTBx strategies when a bronchus sign was present, but bronchoscopy remained more costly overall. For a central lesion and/or radiographic N1-3 disease, convex endobronchial ultrasound with ROSE followed by lung biopsy with incremental cost-effectiveness ratio, if required, was more cost-effective than any CTBx strategy across all outcomes. Strategies with ROSE were always more cost-effective than those without, irrespective of scenario. Trade-offs also exist between different bronchoscopy strategies, and optimal choices depend on the value placed on individual outcomes and willingness-to-pay.

INTERPRETATION

The most cost-effective strategies depend on nodal stage, lesion location, type of peripheral bronchoscopic biopsy, and the use of ROSE. For most clinical scenarios, many strategies can be eliminated, and trade-offs between the remaining competitive strategies can be quantified.

The Utility of Point-of-Care Ultrasound for Post-Bronchoscopy Pneumothorax Evaluation

We present a case of a 65-year-old female with a prior history of B-cell lymphoma with new CT chest findings of a nodule requiring an electromagnetic navigational bronchoscopy with transbronchial biopsies. Post-bronchoscopy, the patient complained of dyspnea and left scapular pain despite two normal anterior-posterior chest X-rays. Point-of-care ultrasound of the lung demonstrated a lack of lung sliding, which was confirmed via a right lateral decubitus chest X-ray. This case illustrates the utility and superiority of lung point-of-care ultrasound while highlighting the limitations of conventional imaging modalities in a post-bronchoscopy evaluation.

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.

An electromagnetic tracking implantation navigation system in dentistry with virtual calibration

BACKGROUND

Dental implant placement navigation systems based on optical tracking have been widely used in clinics. However, electromagnetic (EM) navigation method that does not suffer from problems of hidden line-of-light has not yet been described.

METHODS

This work proposes an EM-guided navigation method named TianShu-ESNS with virtual calibration. Model (12 implants) and animal experiments (pig head: six implants) were conducted to evaluate its performance and stability.

RESULT

The mean virtual calibration error was 0.83 ± 0.20 mm. The mean deviations at the entry point, end point and angle in the phantom experiment of TianShu-ESNS were 1.23 ± 0.17 mm, 1.59 ± 0.20 mm and 1.83 ± 0.27°, respectively. In the animal experiment, the same deviations were 1.25 ± 0.07 mm, 1.57 ± 0.35 mm and 1.90 ± 0.60°, respectively.

CONCLUSIONS

The experimental results show that TianShu-ESNS with the virtual calibration method could serve as a promising tool to eliminate the line-of-light hidden problem and simplify operation procedure in dental implant placement.

Cone-Beam CT Image Guidance With and Without Electromagnetic Navigation Bronchoscopy for Biopsy of Peripheral Pulmonary Lesions

BACKGROUND

Bronchoscopic diagnosis of small peripheral lung lesions suspected of lung cancer remains a challenge. A successful endobronchial diagnosis comprises navigation, confirmation, and tissue acquisition. In all steps, 3-dimensional information is essential. Cone-beam computed tomography (CBCT) imaging can provide computed tomography information and 3-dimensional augmented fluoroscopy imaging. We assessed whether CBCT imaging can improve navigation and diagnosis of peripheral lesions by 2 clinical workflows with a cross-over design: (1) a primary CBCT and radial endobronchial ultrasound mini probe imaging-based approach and (2) a primary electromagnetic navigation (EMN) and radial endobronchial ultrasound mini probe imaging-based approach.

METHODS

All patients with a peripheral lung lesion biopsy indication were eligible for study inclusion and randomly assigned to study arms. Commercially available equipment was used. The main study goals were to assess CBCT-confirmed navigation success and diagnostic accuracy. Surgery or unambiguous clinical follow-up served as the gold standard.

RESULTS

Eighty-seven patients with 107 lesions were included. Lesion mean longest axis size in the CBCT arm was 16.6 mm (n=47) and 14.2 mm in the EMN arm (n=40). The primary CBCT approach and primary EMN approach had 76.3% and 52.2% navigation success, respectively. Addition of EMN to the CBCT approach increased navigation success to 89.9%. Addition of CBCT imaging to the EMN approach significantly increased navigation success to 87.5% per lesion. The overall diagnostic accuracy per patient was significantly lower than the navigation success, being 72.4%.

CONCLUSION

CBCT imaging is a valuable addition to navigation bronchoscopy. Although overall navigation success was high, the diagnostic accuracy remains to be improved. Future research should focus on improving the tissue acquisition methodology.

The endonasal patient reference tracker: a novel solution for accurate noninvasive electromagnetic neuronavigation

OBJECTIVE

Electromagnetic (EM) navigation provides the advantages of continuous guidance and tip-tracking of instruments. The current solutions for patient reference trackers are suboptimal, as they are either invasively screwed to the bone or less accurate if attached to the skin. The authors present a novel EM reference method with the tracker rigidly but not invasively positioned inside the nasal cavity.

METHODS

The nasal tracker (NT) consists of the EM coil array of the AxiEM tracker plugged into a nasal tamponade, which is then inserted into the inferior nasal meatus. Initially, a proof-of-concept study was performed on two cadaveric skull bases. The stability of the NT was assessed in simulated surgical situations, for example, prone, supine, and lateral patient positioning and skin traction. A deviation ≤ 2 mm was judged sufficiently accurate for clinical trial. Thus, a feasibility study was performed in the clinical setting. Positional changes of the NT and a standard skin-adhesive tracker (ST) relative to a ground-truth reference tracker were recorded throughout routine surgical procedures. The accuracy of the NT and ST was compared at different stages of surgery.

RESULTS

Ex vivo, the NT proved to be highly stable in all simulated surgical situations (median deviation 0.4 mm, range 0.0-2.0 mm). In 13 routine clinical cases, the NT was significantly more stable than the ST (median deviation at procedure end 1.3 mm, range 0.5-3.0 mm vs 4.0 mm, range 1.2-11.2 mm, p = 0.002). The loss of accuracy of the ST was highest during draping and flap fixation.

CONCLUSIONS

Application of the EM endonasal patient tracker was found to be feasible with high procedural stability ex vivo as well as in the clinical setting. This innovation combines the advantages of high precision and noninvasiveness and may, in the future, enhance EM navigation for neurosurgery.

Navigational bronchoscopy: a guide through history, current use, and developing technology

The peripheral pulmonary nodule offers unique challenges to the clinician, especially in regards to diagnostic approach. Quite often the etiology of the nodule is spurious, though the specter of malignancy drives accurate classification of the nodule. Diagnostic approaches range in degrees of invasiveness, accuracy, and morbidity. Bronchoscopic access to these nodules had been plagued by low reported yields, especially in fluoroscopically invisible nodules. Navigational bronchoscopy, however, allowed more accurate access to peripheral nodules while maintaining a low morbidity, and thus reshaped the historic diagnostic algorithms. Though navigational bronchoscopy was initially associated with electromagnetic navigation, newer approaches to navigation and new technologies provide enthusiasm that yield can improve. In this article we will provide a historical approach to navigational bronchoscopy, from its origins to its current state, and we will discuss developing technology and its potential role in the evolving paradigm of the peripheral nodule biopsy.

Sensitivity and Safety of Electromagnetic Navigation Bronchoscopy for Lung Cancer Diagnosis: Systematic Review and Meta-analysis

BACKGROUND

Bronchoscopy is a useful tool for the diagnosis of lesions near central airways; however, the diagnostic accuracy of these procedures for peripheral pulmonary lesions (PPLs) is a matter of ongoing debate. In this setting, electromagnetic navigation bronchoscopy (ENB) is a technique used to navigate and obtain samples from these lesions. This systematic review and meta-analysis aims to explore the sensitivity of ENB in patients with PPLs suspected of lung cancer.

RESEARCH QUESTION

In patients with peripheral pulmonary lesion suspected of lung cancer, what is the sensitivity and safety of electromagnetic navigation bronchoscopy compared to surgery or longitudinal follow up?

STUDY DESIGN AND METHODS

A comprehensive search of several databases was performed. Extracted data included sensitivity of ENB for malignancy, adequacy of the tissue sample, and complications. The study quality was assessed using the QUADAS-2 tool, and the combined data were meta-analyzed using a bivariate method model. A summary receiver operatic characteristic curve (sROC) was created. Finally, the quality of evidence was rated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Forty studies with a total of 3,342 participants were included in our analysis. ENB reported a pooled sensitivity of 77% (95% CI, 72%-82%; I² = 80.6%) and a specificity of 100% (95% CI, 99%-100%; I² = 0%) for malignancy. The sROC showed an area under the curve of 0.955 (P = .03). ENB achieved a sufficient sample for ancillary tests in 90.9% (95% CI, 84.8%-96.9%; I² = 80.7%). Risk of pneumothorax was 2.0% (95% CI, 1.0-3.0; I² = 45.2%). We found subgroup differences according to the risk of bias and the number of sampling techniques. Meta-regression showed an association between sensitivity and the mean distance of the sensor tip to the center of the nodule, the number of tissue sampling techniques, and the cancer prevalence in the study.

INTERPRETATION

ENB is very safe with good sensitivity for diagnosing malignancy in patients with PPLs. The applicability of our findings is limited because most studies were done with the superDimension navigation system and heterogeneity was high.

TRIAL REGISTRY

PROSPERO; No.: CRD42019109449; URL: https://www.crd.york.ac.uk/prospero/.

The comparison of electromagnetic with virtual bronchoscopic navigation accuracy at hybrid operating room in patient with sternal wires

We describe a case of a 63-year-old lady with an incidental small right upper lobe ground glass opacity (GGO) lesion, who had history of open-heart surgery with bypass grafts for coronary artery disease. Video-assisted thoracic surgery (VATS) excisional biopsy with pre-operative localization was planned. Localization by percutaneous approach is challenging due to position of GGO shielded by both the scapular and ribs. Electromagnetic navigation accuracy may be affected by steel sternal wires but its effect has not been reported on literature. Both virtual and electromagnetic navigation bronchoscopy platforms were used with real-time cone-beam CT confirmation in the hybrid operating room to perform dye marking. Both navigation methods successfully marked the GGO for lung resection. Our case demonstrated that the accuracy of electromagnetic navigation in the presence of steel sternal wire is satisfactory for dye marking and the use of intra-operative cone-beam CT in hybrid operating room is invaluable for the success of navigational bronchoscopy.

[Use of navigation in skull base surgery]

The review briefly presents the history of development of navigation systems in neurosurgery. The idea of the existing principles underlying the navigation systems used in neurosurgery is given. Currently, the basic principles of navigation are optical and electromagnetic. Studies are presented comparing the accuracy of various navigation systems. Optical navigation demonstrates greater accuracy compared to electromagnetic, but both methods demonstrate a submillimeter error in the experiment. The history of use of navigation in the surgery of the skull base is analyzed in detail, the most relevant areas of use of navigation within the surgery of the skull base are considered: craniofacial reconstruction, endoscopic endonasal surgery, surgery of common tumors of the skull base affecting the infratemporal, pterygopalatine fossa, temporomandibular joint. Indications for the use of navigation, limitations of the methodology are explained.

Automatic Registration for Navigation at the Anterior and Lateral Skull Base

OBJECTIVE

Navigation systems create a connection between imaging data and intraoperative situs, allowing the surgeon to consistently determine the location of instruments and patient anatomy during the surgical procedure. The best results regarding the target registration error (measurement uncertainty) are normally demonstrated using fiducials. This study aimed at investigating a new registration strategy for an electromagnetic navigation device.

METHODS

For evaluation of an electromagnetic navigation system and comparison of registration with screw markers and automatic registration, we are calculating the target registration error in the region of the paranasal sinuses/anterior and lateral skull base with the use of an electromagnetic navigation system and intraoperative digital volume tomography (cone-beam computed tomography). We carried out 10 registrations on a head model (total n = 150 measurements) and 10 registrations on 4 temporal bone specimens (total n = 160 measurements).

RESULTS

All in all, the automatic registration was easy to perform. For the models that were used, a significant difference between an automatic registration and the registration on fiducials was evident for just a limited number of screws. Furthermore, the observed differences varied in terms of the preferential registration procedure.

CONCLUSION

The automatic registration strategy seems to be an alternative to the established methods in artificial and cadaver models of intraoperative scenarios. Using intraoperative imaging, there is an option to resort to this kind of registration as needed.

[Application of image-guided system in endoscopic sinus and skull base surgery]

Objective:To evaluate the applicative value of image-guided system in endoscopic sinus and skull base surgeries. Method:A total of 103 endoscopic surgical procedures were performed.All these procedures were conducted with the utilization of image-guided system, among which there were 92 cases of sinonasal-skull base surgery(including nasal sinuses resection of benign and malignant tumors involving skull base lesions, the cumulative orbital lesion resection of nasal sinus lesions, etc. ), 6 repair of cerebrospinal fluid leak, 3 pituitary adenoma resection, 2 traumatic neuropathy optic nerve decompression. Result:With the utilization of image-guided system, all patients had successful surgery without major and minor complications. The image-guided system provided high precision with short registration time. Conclusion:Image-guided system can help the surgeon to identify accurately the vital anatomic landmarks of sinus and skull base, improving surgical accuracy and safety as well as reducing or avoiding the intraoperative and postoperative complications.

Peripheral tumour targeting using open-source virtual bronchoscopy with electromagnetic tracking: a multi-user pre-clinical study

Objectives: The goal was to demonstrate the utility of open-source tracking and visualisation tools in the targeting of lung cancer.Material and methods: The study demonstrates the first deployment of the Anser electromagnetic (EM) tracking system with the CustusX image-guided interventional research platform to navigate using an endobronchial catheter to injected tumour targets. Live animal investigations validated the deployment and targeting of peripheral tumour models using an innovative tumour marking routine.Results: Novel tumour model deployment was successfully achieved at all eight target sites across two live animal investigations without pneumothorax. Virtual bronchoscopy with tracking successfully guided the tracked catheter to 2-12 mm from the target tumour site. Deployment of a novel marker was achieved at all eight sites providing a reliable measure of targeting accuracy. Targeting accuracy within 10 mm was achieved in 7/8 sites and in all cases, the virtual target distance at marker deployment was within the range subsequently measured with x-ray.Conclusions: Endobronchial targeting of peripheral airway targets is feasible using existing open-source technology. Notwithstanding the shortcomings of current commercial platforms, technological improvements in EM tracking and registration accuracy fostered by open-source technology may provide the impetus for widespread clinical uptake of electromagnetic navigation in bronchoscopy.

Electromagnetic navigation bronchoscopy: clinical utility in the diagnosis of lung cancer

Electromagnetic navigation bronchoscopy (ENB) is one of several technological advances which have broadened the indications for bronchoscopy in the diagnostic workup of lung cancer. The technique facilitates bronchoscopic sampling of peripheral pulmonary nodules as well as mediastinal lymph nodes, although wide availability and expertise in endobronchial ultrasonography has limited its application in routine clinical practice to the former. ENB in this setting is quite versatile and may be considered an established alternative to more invasive techniques, especially in selected patients with underlying pulmonary disease or comorbidities at high risk for complications from computer topography-guided fine needle aspiration or surgical resection. Nodule sampling may be performed with a variety of instruments, including forceps, cytology brushes, and transbronchial needles. Although samples are generally small, they are often suitable for molecular analysis.

Diagnostic Yield and Complications of Bronchoscopy for Peripheral Lung Lesions. Results of the AQuIRE Registry

RATIONALE

Advanced bronchoscopy techniques such as electromagnetic navigation (EMN) have been studied in clinical trials, but there are no randomized studies comparing EMN with standard bronchoscopy.

OBJECTIVES

To measure and identify the determinants of diagnostic yield for bronchoscopy in patients with peripheral lung lesions. Secondary outcomes included diagnostic yield of different sampling techniques, complications, and practice pattern variations.

METHODS

We used the AQuIRE (ACCP Quality Improvement Registry, Evaluation, and Education) registry to conduct a multicenter study of consecutive patients who underwent transbronchial biopsy (TBBx) for evaluation of peripheral lesions.

MEASUREMENTS AND MAIN RESULTS

Fifteen centers with 22 physicians enrolled 581 patients. Of the 581 patients, 312 (53.7%) had a diagnostic bronchoscopy. Unadjusted for other factors, the diagnostic yield was 63.7% when no radial endobronchial ultrasound (r-EBUS) and no EMN were used, 57.0% with r-EBUS alone, 38.5% with EMN alone, and 47.1% with EMN combined with r-EBUS. In multivariate analysis, peripheral transbronchial needle aspiration (TBNA), larger lesion size, nonupper lobe location, and tobacco use were associated with increased diagnostic yield, whereas EMN was associated with lower diagnostic yield. Peripheral TBNA was used in 16.4% of cases. TBNA was diagnostic, whereas TBBx was nondiagnostic in 9.5% of cases in which both were performed. Complications occurred in 13 (2.2%) patients, and pneumothorax occurred in 10 (1.7%) patients. There were significant differences between centers and physicians in terms of case selection, sampling methods, and anesthesia. Medical center diagnostic yields ranged from 33 to 73% (P = 0.16).

CONCLUSIONS

Peripheral TBNA improved diagnostic yield for peripheral lesions but was underused. The diagnostic yields of EMN and r-EBUS were lower than expected, even after adjustment.

Community hospital experience using electromagnetic navigation bronchoscopy system integrating tidal volume computed tomography mapping

Results of the first 50 consecutive patients referred for bronchoscopy or surgery by the tumor review board to confirm suspect lung lesions identified by computed tomography. Electromagnetic navigation was used to biopsy peripheral pulmonary nodules, (19.3 ± 10.7 mm). An electromagnetic tracking system was used to detect miniature position sensors integrated directly into tip-tracked instruments advanced through a 2 mm working channel in a bronchoscope. Learning curve, diagnostic yield, safety and use of the 4D positional information on the patient's tidal volume expiration computed tomography map demonstrate a potential to improve the diagnostic yield of transbronchial biopsies of peripheral pulmonary nodules less than 30 mm reporting a diagnostic yield of 83.3% (40/48). Early experience was safe and effective, with a limited learning curve.

Electromagnetic navigation-guided TBNA vs conventional TBNA in the diagnosis of mediastinal lymphadenopathy

OBJECTIVES

Conventional transbronchial needle aspiration (C-TBNA) is a safe method for the diagnosis of hilar and mediastinal lymphadenopathy (MLN). However, diagnostic yield of this technique varies considerably. Electromagnetic navigation bronchoscopy (ENB) is a new technology to increase the diagnostic yield of flexible bronchoscopy for the peripheral lung lesions and MLN. The aim of this prospective study was to compare the diagnostic and sampling success of ENB-guided TBNA (ENB-TBNA) in comparison with C-TBNA while dealing with MLN.

METHODS

Consecutive patients with MLN were randomized into two groups - C-TBNA and ENB-TBNA - using a computer-based number shuffling system to avoid recruitment bias. Procedures were performed in usual fashion, published previously.

RESULTS

Ninety-four cases (M/F: 45/49) with a total of 145 stations of MLN were enrolled in the study. In 44 patients, 81 stations were sampled by ENB-TBNA, and in 50 patients 64 stations by C-TBNA. The mean size of MLN in study subjects was 17.56 ± 6.25 mm. The sampling success was significantly higher in ENB-TBNA group (82.7%) compared with C-TBNA group (51.6%) (P < 0.005). Defined by histopathological result, the diagnostic yield in ENB-TBNA was 72.8%, and 42.2% with C-TBNA (P < 0.005). For subcarinal localization, sampling or diagnostic success was higher in ENB-TBNA than that of C-TBNA (P < 0.05). Based on the size of the MLN ≤15 mm or >15 mm, the sampling success of ENB-TBNA was also significantly higher than C-TBNA in both subgroups (P < 0.005 and P < 0.005, respectively). No serious complication was observed.

CONCLUSION

In this study comparing ENB-TBNA and C-TBNA, the sampling and diagnostic success of ENB-TBNA was found to be superior while dealing with MLN, in all categories studied.

Thoracoscopic detection of occult indeterminate pulmonary nodules using bronchoscopic pleural dye marking

BACKGROUND

The annual incidence of a small indeterminate pulmonary nodule (IPN) on computed tomography (CT) scan remains high. While traditional paradigms exist, the integration of new technologies into these diagnostic and treatment algorithms can result in alternative, potentially more efficient methods of managing these findings.

METHODS

We report on an alternative diagnostic and therapeutic strategy for the management of an IPN. This approach combines electromagnetic navigational bronchoscopy (ENB) with an updated approach to placement of a pleural dye marker. This technique lends itself to a minimally invasive wedge resection via either video-assisted thoracoscopic surgery (VATS) or a robotic approach.

RESULTS

Subsequent to alterations in the procedure, a cohort of 22 patients with an IPN was reviewed. Navigation was possible in 21 out of 22 patients with one patient excluded based on airway anatomy. The remaining 21 patients underwent ENB with pleural dye marking followed by minimally invasive wedge resection. The median size of the nodules was 13.4 mm (range: 7-29). There were no complications from the ENB procedure. Indigo carmine dye was used in ten patients. Methylene blue was used in the remaining 11 patients. In 81% of cases, the visceral pleural marker was visible at the time of surgery. In one patient, there was diffuse staining of the parietal pleura. In three additional patients, no dye was identified within the hemithorax. In all cases where dye marker was present on the visceral pleural surface, it was in proximity to the IPN and part of the excised specimen.

CONCLUSIONS

ENB with pleural dye marking can provide a safe and effective method to localize an IPN and can allow for subsequent minimally invasive resection. Depending on the characteristics and location of the nodule, this method may allow more rapid identification intraoperatively.

Percutaneous antegrade scaphoid screw placement: a feasibility and accuracy analysis of a novel electromagnetic navigation technique versus a standard fluoroscopic method

BACKGROUND

Central screw positioning in the scaphoid provides biomechanical advantages.

METHODS

A prospective randomized study of six fluoroscopically guided and six electromagnetically navigated screw (ENS) placements was performed on human cadavers. Accuracy of screw position was determined. Intraoperative fluoroscopy exposure times, readjustments of drilling directions, complete restarts and complications were documented.

RESULTS

The ENS method provided a mean time benefit of 7.34 min compared with the standard method and the mean screw length ratio (SLR coronar: ENS 0.96 ± 0.04 mm, SFF: 0.92 ± 0.04 mm, P = 0.065; SLR sagittal: ENS 0.98 ± 0.02 mm, SFF: 0.91 ± 0.04 mm, P = 0.009) and the screw axis deviation angle (AD coronar: ENS 3.33 ± 2.34°, SFF: 10.33 ± 2.58°, P = 0.002; AD sagittal: ENS 2.83 ± 0.98°, SFF: 11.00 ± 6.16°, P = 0.002) were lower. Using the electromagnetic navigation procedure no drilling readjustments or restarts were required, no cortical breach occurred.

CONCLUSIONS

Compared with the standard fluoroscopic technique, the ENS method used in this study showed higher accuracy, less complications, required less operation and radiation exposure time.

Advances in bronchoscopy for lung cancer

Bronchoscopic techniques have seen significant advances in the last decade. The development and refinement of different types of endobronchial ultrasound and navigation systems have led to improved diagnostic yield and lung cancer staging capabilities. The complication rate of these minimally invasive procedures is extremely low as compared to traditional transthoracic needle biopsy and surgical sampling. These advances augment the safe array of methods utilized in the work up and management algorithms of lung cancer.