Localization of pulmonary nodules using navigation bronchoscope and a near-infrared fluorescence thoracoscope

Current Status and Future Perspectives of Preoperative and Intraoperative Marking in Thoracic Surgery

The widespread implementation of lung cancer screening and thin-slice computed tomography (CT) has led to the more frequent detection of small nodules, which are commonly referred to thoracic surgeons. Surgical resection is the final diagnostic and treatment option for such nodules; however, surgeons must perform preoperative or intraoperative markings for the identification of such nodules and their precise resection. Historically, hook-wire marking has been performed more frequently worldwide; however, lethal complications, such as air embolism, have been reported. Therefore, several surgeons have recently attempted to develop novel preoperative and intraoperative markers. For example, transbronchial markings, such as virtual-assisted lung mapping and intraoperative markings using cone-beam computed tomography, have been developed. This review explores various marking methods that have been practically applied for a better understanding of preoperative and intraoperative markings in thoracic surgery. Recently, several attempts have been made to perform intraoperative molecular imaging and dynamic virtual three-dimensional computed tomography for the localization, diagnosis, and margin assessment of small nodules. In this narrative review, the current status and future perspectives of preoperative and intraoperative markings in thoracic surgery are examined for a better understanding of these techniques.

Chemical Localization With Robotic Bronchoscopy: Can It Aid Resection of Subsolid Lung Nodules?

INTRODUCTION

Subsolid nodules or those located deep in lung parenchyma are difficult to localize using minimally invasive thoracic surgery. While image-guided percutaneous needle localization has been performed, it is inconvenient and has potential complications. In this study, the role of chemical localization using robotic bronchoscopy to facilitate resection was evaluated.

METHODS

Consecutive patients undergoing surgical resection for lung nodules between 8/2019-3/2022 were included. Patients with subsolid lung nodules, or small nodules deep in lung parenchyma that were deemed difficult to localize, were chemically localized (CL) using robotic bronchoscopy before resection. Clinico-demographic data were obtained retrospectively using a prospectively maintained database.

RESULTS

Localization of lung nodules before resection was performed in 139 patients while 110 patients were not localized. Daily activity score was higher for localized patients. Nodules in the localized group were smaller (P < 0.001) and had similar solid:ground glass ratio. In the localized group, larger margins were observed, and no re-resection of the parenchymal margin was required. Twenty patients in the non-localized group required re-resection intraoperatively due to close pathological margins or inability to locate the nodule in the resected specimen. Operative time was a median of 10-15 min longer for localized patients, P < 0.001. Length of stay was shorter in the localized group (P < 0.05).

CONCLUSIONS

Chemical localization of lung nodules using robotic bronchoscopy appears to be a safe and effective method of identifying the location of nodules with small size and less density and aids increased tumor margins intraoperatively.

A novel, simple near-infrared thoracoscopic technique by a particular route for locating lung nodules

Background

The localization of pulmonary nodules prior to thoracoscopic surgery remains challenging for thoracic surgeons, especially for those nodules that are not visible or palpable on the lung surface. Our study is a simple and effective minimally invasive method using indocyanine green through a special pathway to locate pulmonary nodules and fluorescence thoracoscopic surgery.

Methods

Thoracoscopic surgery was performed for 18 undiagnosed peripheral non-solid nodules no larger than 2 cm after location. After 0.3 mg/kg indocyanine green was injected through the peripheral vein, the puncture needle was pulled out after it reached approximately 1 cm of the pulmonary parenchyma near the nodules. This was followed by transfer to the operating room. The nodule was initially localized by using a near-infrared thoracoscope to visualize indocyanine green fluorescence. Then, thoracoscopic resection was performed.

Results

Eighteen patients received this special and simple localization method, and underwent near-infrared, image-guided, video-assisted thoracoscopic surgery resection. Median computed tomography (CT) tumor size was 1.2 cm. Median depth from the pleural surface is 1.6 cm (range, 0.1-4.6 cm). The median time of CT-guided intervention was 12 min. The duration of thoracoscopic surgery was 67 min. Indocyanine green fluorescence was clearly identified in 17 of 18 patients (94.4%). The surgical margins were all negative on final pathology. The final diagnoses included 17 primary lung cancers, and 1 benign lung tumor.

Conclusions

CT-guided single puncture of indocyanine green after peripheral intravenous injection is a simple, effective, and safe method to locate the nodule. This offers surgeons the ease of localization through direct indocyanine green fluorescence imaging, and it can be used as an effective alternative to other placement methods of locating pulmonary nodules.

Percutaneous Computed Tomography (CT)-Guided Localization with Indocyanine Green for the Thoracoscopic Resection of Small Pulmonary Nodules

BACKGROUND

The identification of small lung nodules is challenging during mini-invasive thoracic surgery. Unable to palpate them directly, surgeons have developed several methods to preoperatively localize pulmonary nodules, including the computed tomography-guided positioning of coils or metallic landmarks (hook wire) or bronchoscopic marking.

METHODS

We present a series of patients scheduled for the video-assisted thoracoscopic sublobar resection of small pulmonary nodules, in which we performed preoperative percutaneous computed tomography (CT)-guided nodule localization through the injection of a mixture of indocyanine green and human albumin.

RESULTS

A total of 40 patients underwent a preoperative CT-guided injection of indocyanine green followed by VATS resection within 24 h. Patients tolerated the procedure well, no pain medication was administrated, and no complications were observed during the marking procedure. All pulmonary nodules were easily detected and successfully resected.

CONCLUSION

the near-infrared dye marking solution of indocyanine green (ICG) with diluted human albumin was safe, effective, and easy to perform. The ICG solution has the potential to facilitate the accurate localization and resection of pulmonary nodules during VATS surgery, avoiding the risk of marker displacement/migration.

The efficacy and safety of an indocyanine green-hyaluronic acid mixture (LuminoMark™) for localization in patients with non-palpable breast lesions: A multicenter, randomized, open-label, parallel phase 3 clinical trial

Purpose

The incidence of early tumor detection is increasing due to popularization of breast cancer screening and the development of imaging techniques. Thus, suitable preoperative localization is required for proper diagnosis and treatment of non-palpable breast lesions. The purpose of this study was to evaluate the efficacy and safety of indocyanine green (ICG)-hyaluronic acid (HA) mixture for lesion localization compared to activated charcoal.

Methods

This was a multicenter, randomized, open-label, parallel phase 3 clinical trial performed at four centers in Korea. Female patients scheduled for surgery to remove non-palpable breast lesions were enrolled. One hundred and nine patients were randomly assigned to a control group (activated charcoal: 0.3. - 1 mL) or a study group (ICG-HA mixture, 0.2 mL) for the localization of a breast lesion. The primary endpoint was the accuracy of resection. Secondary endpoints included the technical success rate, histopathological accuracy, skin pigmentation rate, and adverse event rate.

Results

A total of 104 patients were eligible for per-protocol analysis (control group, n = 51; study group, n = 53). The accuracy of resection in the study group was not inferior to that of the control group (90.57% vs. 98.04%, 95% confidence interval (CI): -2.31 - 18.91, p = 0.21). There was no statistically significant difference in technical success rate between the two groups (marking on breast skin: p = 0.11, marking on the excised specimen: p = 0.12). However, there were statistically significant differences in histopathological accuracy (0.26 ± 0.13 vs. 0.33 ± 0.17, p = 0.01) and skin pigmentation rate (0.00% vs. 30.77%, p< 0.01). Adverse events were not reported in either group.

Conclusions

When localization was performed using ICG-HA, the accuracy of resection was not inferior to that of activated charcoal. However, skin pigmentation rate was significantly lower. In conclusion, ICG-HA is effective and safe for localizing of non-palpable breast lesions.

Applicability of autofluorescence and fluorescent probes in the trans-surgical of oral carcinomas: A systematic review

Oral cancer represents an important health problem, as it is the sixth most common type of cancer in the world and is associated with high rates of morbidity and mortality. The treatment considered the gold standard for this type of tumor is surgical resection with negative margins, with a distance of at least 5 mm from the tumor. This procedure is strongly associated with local control and disease-specific survival, however, in many cases, large amounts of healthy tissue are removed, resulting in surgical defects, compromising various functions and directly affecting the individual's quality of life. From this perspective, this systematic review aimed to evaluate the use of autofluorescence and fluorescent probes as potential adjuvant techniques to facilitate the delineation of surgical margins for oral cancers. A comprehensive search was performed in Pubmed, Scopus, Web of Science, LIVIVO, Embase, ProQuest Open Access Dissertations & Theses, Open Access Theses and Dissertations, and DART Europe databases, where 1948 articles were found. After the different stages of critical evaluation, 15 articles were selected, eligible for the inclusion criteria. Of these, 7 articles used autofluorescence, 7 used fluorescent probes and 1 article used both methods. As for autofluorescence, the most used device was the VELScope, and indocyanine green was the most used probe. Compared to histopathology, autofluorescence did not obtain significant and/or superiors results. In contrast to fluorescent probes that, most articles showed a good performance of margins during surgical resection, making them a promising alternative. However, it is still necessary to carry out the analysis of more articles, with more significant samples and sensitivity and specificity data to qualify the results.

Expert consensus on indocyanine green fluorescence imaging for thoracoscopic lung resection (The Version 2022)

The use of the white-light thoracoscopy is hampered by the low contrast between oncologic margins and surrounding normal parenchyma. As a result, many patients with in situ or micro-infiltrating adenocarcinoma have to undergo lobectomy due to a lack of tactile and visual feedback in the resection of solitary pulmonary nodules. Near-infrared (NIR) guided indocyanine green (ICG) fluorescence imaging technique has been widely investigated due to its unique capability in addressing the current challenges; however, there is no special consensus on the evidence and recommendations for its preoperative and intraoperative applications. This manuscript will describe the development process of a consensus on ICG fluorescence-guided thoracoscopic resection of pulmonary lesions and make recommendations that can be applied in a greater number of centers. Specifically, an expert panel of thoracic surgeons and radiographers was formed. Based on the quality of evidence and strength of recommendations, the consensus was developed in conjunction with the Chinese Guidelines on Video-assisted Thoracoscopy, and the National Comprehensive Cancer Network (NCCN) guidelines on the management of pulmonary lesions. Each of the statements was discussed and agreed upon with a unanimous consensus amongst the panel. A total of 6 consensus statements were developed. Fluorescence-guided thoracoscopy has unique advantages in the visualization of pulmonary nodules, and recognition and resection of the anterior plane of the pulmonary segment. The expert panel agrees that fluorescence-guided thoracoscopic surgery has the potential to become a routine operation for the treatment of pulmonary lesions.

Localization Technique Using Mixture of Indigo Carmine and Lipiodol of Pulmonary Nodule via Bronchoscopic Navigation

Background and Objectives: As the number of minimally invasive surgeries, including video-assisted thoracoscopic surgery, increases, small, deeply located lung nodules are difficult to visualize or palpate; therefore, localization is important. We studied the use of a mixture of indigo—carmine and lipiodol, coupled with a transbronchial approach—to achieve accurate localization and minimize patient discomfort and complications. Materials and Methods: A total of 60 patients were enrolled from May 2019 to April 2022, and surgery was performed after the bronchoscopy procedure. Wedge resection or segmentectomy was performed, depending on the location and size of the lesion. Results: In 58/60 (96.7%) patients, the localization of the nodules was successful after localization, and 2/60 required c-arm assistance. None of the patients complained of discomfort during the procedure; in all cases, margins were found to be free from carcinoma, as determined by the final pathology results. Conclusions: We recommend this localization technique using mixture of indigo carmine and lipiodol, in concert with the transbronchial approach, because the procedure time is short, patient’s discomfort is low, and success rate is high.

Intraoperative electromagnetic navigation bronchoscopy (IENB) to localize peripheral lung lesions: A new technique in the pediatric oncology population

BACKGROUND

The utility, diagnostic yield and accuracy of lung biopsies in pediatric oncology patients are variable. Here we describe our preliminary results using intraoperative electromagnetic navigation bronchoscopy (IENB) for peripheral lung lesions to increase the surgical yield and accuracy in pediatric oncology patients.

METHODS

From May 2018 until October 2020 all surgical lung biopsies on pediatric oncology patients were performed using IENB technology. IENB and tattooing with methylene blue dye, Indocyanine green dye or both followed by Video-assisted Thoracoscopic Surgery (VATS) was performed in the same setting. Data were collected retrospectively. Data points included diagnosis, technical success, pathologic diagnosis and alteration in treatment management and complications.

RESULTS

A total of 10 biopsy procedures were performed on 8 patients during the study. The youngest patient was 7 years old. All had successful IENB with tattooing. All biopsies were diagnostic. No procedures were converted to open. There were no technical failures or procedure complications. One patient had a total of 11 biopsies, 6 from the right lung and 5 from the left, performed at 2 separate procedures. Another had 2 biopsies, one from the right lung and one from the left performed at the same operation. In 7 of the 8 patients treatment changes were made based on results of their biopsy.

CONCLUSION

Here we present the first described experience of IENB and tattooing of peripheral lung lesions in the pediatric population. We have shown that IENB for peripheral lung lesion localization is a safe and effective technique in pediatric oncology.

Nomogram Prediction Model Analysis of Risk Factors for Conversion to Thoracotomy after Thoracoscopic Resection of Lung Cancer and Prognostic Value of Lung Cancer

This study was aimed at exploring the risk factors for thoracotomy in patients undergoing thoracoscopic resection of lung cancer and further analyzing the factors affecting the prognosis of patients. Ninety-six patients with non-small-cell lung cancer who underwent thoracoscopic pulmonary resection were recruited as the subjects, and they were enrolled into the thoracoscopic group (n = 88) and the thoracotomy group (n = 8) according to whether thoracotomy was performed. Univariate analysis and logistic multivariate regression were performed to analyze the risk factors for conversion to thoracotomy, and nomogram prediction model was employed to analyze the prognostic factors. The results revealed that the proportion of patients over 65 years old, with history of coronary heart disease, diabetes, and pulmonary tuberculosis, etc., in the thoracotomy group and the thoracoscopic group was significantly different (P < 0.05). There were statistically significant differences in the development of interlobular cleft, pleural adhesion, tumor diameter > 3.5 cm, vascular and lymph node invasion, and tumor TNM stage between the thoracotomy group and the thoracoscopic group (P < 0.05). Overall, the age of patients ≥ 65 years old, tumor diameter > 3.5 cm, hypoplasia of interlobular fissure, history of pulmonary tuberculosis, pleural adhesion, and TNM stage IIIa were all independent risk factors for thoracoscopic resection of lung cancer to thoracotomy. Cox model and nomogram prediction model analysis showed that surgery methods, tumor diameter > 3.5 cm, chemotherapy cycle < 4, chemotherapy, and TNM stage IIIa were all independent factors influencing the prognosis of patients undergoing thoracoscopic lung cancer resection. This nomogram prediction model had high application value in patient prognosis prediction.

Robotic Assisted-Bronchoscopy With Cone-Beam CT ICG Dye Marking for Lung Nodule Localization: Experience Beyond USA

Electromagnetic navigation bronchoscopy (ENB)-guided indocyanine green (ICG) fluorescence dye marking of subsolid, small and deep lung lesions facilitates subsequent minimally invasive lung resection surgeries. The novel robotic-assisted bronchoscopy (RAB) platform can improve the accuracy and yield of ENB biopsy, and the use of RAB has been extended to ICG dye marking. However, performing this procedure in the hybrid operating room guided by cone-beam CT (CBCT) with immediate proceed to lung surgery has not been well reported. We studied the safety, feasibility and clinical outcomes of 5 consecutive cases performed between December 2021 and March 2022. Navigation success was 100% while localization success using ICG was 80%. The benefits and pitfalls of robotic bronchoscopy procedures, and challenges of combining with hybrid operating room CBCT were discussed in detail. In conclusion, robotic-assisted bronchoscopy is a promising and useful tool for ICG fluorescence dye-marking, providing accurate navigation, superior maneuverability and improved ergonomics compared to conventional bronchoscopy-guided ENB procedures. Learning curve is reasonable, but meticulous system set up to incorporate the robotic system into existing CBCT platform may be required to ensure a smooth procedure.

Synchronous resection of 12 small pulmonary nodules guided by a noninvasive 3D printed emulation model: A case report

Localization of multiple small pulmonary nodules is the major obstacle in surgical resection. Here, we report a novel noninvasive localization technique based on a life-size 3D printed "emulation pulmonary nodule localization model" which is simple and efficient. In the case reported here of a patient with synchronous multiple pulmonary nodules, the nodules were successfully and conveniently localized without any trauma by navigation of the emulation localization model. All 12 nodules were resected precisely and thoroughly, while normal lung tissues were considerably well preserved. Pathological examination confirmed malignancy of the major nodule and some other small nodules.

Raman-Guided Bronchoscopy: Feasibility and Detection Depth Studies Using Ex Vivo Lung Tissues and SERS Nanoparticle Tags

Image-guided and robotic bronchoscopy is currently under intense research and development for a broad range of clinical applications, especially for minimally invasive biopsy and surgery of peripheral pulmonary nodules or lesions that are frequently discovered by CT or MRI scans. Optical imaging and spectroscopic modalities at the near-infrared (NIR) window hold great promise for bronchoscopic navigation and guidance because of their high detection sensitivity and molecular/cellular specificity. However, light scattering and background interference are two major factors limiting the depth of tissue penetration of photons, and diseased lesions such as small tumors buried under the tissue surface often cannot be detected. Here we report the use of a miniaturized Raman device that is inserted into one of the bronchoscope channels for sensitive detection of “phantom” tumors using fresh pig lung tissues and surface-enhanced Raman scattering (SERS) nanoparticle tags. The ex vivo results demonstrate not only the feasibility of using Raman spectroscopy for endoscopic guidance, but also show that ultrabright SERS nanoparticles allow detection through a bronchial wall of 0.85 mm in thickness and a 5 mm-thick layer of lung tissue (approaching the fourth-generation airway). This work highlights the prospects and potential of Raman-guided bronchoscopy for minimally invasive imaging and detection of lung lesions.

Safety and Efficacy of Cone-Beam Computed Tomography-Guided Lung Tumor Localization with a Near-Infrared Marker: A Retrospective Study of 175 Patients

Preoperative localization holds promise for overcoming the limitations of video-assisted thoracoscopic surgery (VATS) in the treatment of impalpable lung nodules. The purpose of this study was to assess the safety and efficacy of cone-beam computed tomography (CBCT)-guided localization using near-infrared (NIR) marking. Between 2017 and 2021, patients presenting with a solitary pulmonary nodule (SPN) who had undergone CBCT-guided lesion localization with indocyanine green (ICG) in a hybrid operating room were included. The primary outcomes were the efficacy of localization and the occurrence of complications. The study cohort consisted of 175 patients with the mean age of 58.76 years. The mean size and depth of the 175 SPNs were 8.34 mm and 5.3 mm, respectively. The mean time required for lesion marking was 14.71 min. Upon thoracoscopic inspection, the NIR tattoo was detected in the vast majority of the study participants (98.3%). An utility thoracotomy to allow digital palpation was required in two of the three patients in whom the tattoo was not identifiable. The perioperative survival rate was 100%, and the mean length of hospital stay was 3.09 days. We conclude that needle localization with ICG injection is a safe and feasible technique to localize SPNs prior to resection.

[Application and Progress of Electromagnetic Navigation Bronchoscopy in Department of Thoracic Surgery]

Lung cancer ranks the first cancer-related morbidity and mortality in China. With the development and penetration of imaging technology, increasing small pulmonary peripheral Nodules (SPPNs) have been detected. However, precise location and diagnosis of SPPNs is still a tough problem for clinical diagnosis and treatment in department of thoracic surgery. With the development of electromagnetic navigation bronchoscopy (ENB), it provides a novel minimally invasive method for the diagnosis and treatment of SPPNs. In this review, we summarized the application and progress of ENB in preoperative positioning, diagnosis, and local treatment, then, discussed the clinical application of ENB in the hybrid operating room.
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Intraoperative cone-beam computed tomography to secure the surgical margin in pulmonary wedge resection for indistinct intrapulmonary lesions

Objective

The objective of this study was to use cone-beam computed tomography (CBCT) for intraoperative imaging of a pulmonary wedge resection line that contributes to securing the required surgical margin in patients undergoing thoracoscopic surgery for indistinct intrapulmonary lesions.

Methods

Data of 16 consecutive patients with potentially impalpable intrapulmonary lesions were retrospectively reviewed. Preoperatively, we simulated a rhomboidal cut line on the surface of a 3-dimensional lung model with reference to multiplanar reconstruction computed tomography images. Intraoperatively, we imaged the rhomboid on the real lung surface using trial and error adjustment with CBCT. Wedge resection was performed thoracoscopically by stapling along the outline of the rhomboid.

Results

The mean consolidation diameter and mean distance between the tumor and the visceral pleura were 2 mm and 11 mm, respectively. In all cases, we only performed single CBCT scanning to localize the rhomboid on the real lung surface. The mean radiological distance between the approximate location and the correct location was 8 mm (range, 0-34 mm). Wedge resection was successful with a mean surgical margin of 11 mm (range, 7-16 mm), without conversion to anatomical resection or open conversion. This simulation was also helpful for planning port placement for the use of an autostapler.

Conclusions

We established a novel procedure for imaging the cut line on the lung surface with intraoperative CBCT, which facilitated the performance of wedge resection with the required surgical margin in patients with potentially impalpable intrapulmonary small lesions. Our method might be beneficial for patients and surgeons because it can be applied without preoperative intervention.

Augmented reality navigation-guided pulmonary nodule localization in a canine model

Background

The current intraoperative pulmonary nodule localization techniques require specific medical equipment or skillful operators, which limits their widespread application. Here, we present an innovative nodule localization technique in a canine lung model using augmented reality (AR) navigation.

Methods

Peripheral pulmonary lesions were artificially created in canine model. A preoperative chest computed tomography scan was performed for each animal. The acquired computed tomography images were analyzed, and an established intraoperative localization plan was uploaded into HoloLens (a head-mounted AR device). Under general anesthesia, lung localization markers were implanted in each canine, guided by the established procedure plan displayed by HoloLens. All artificial lesions and markers were removed by video-assisted wedge resection or lobectomy in a single operation.

Results

Since June 2019, 12 peripheral pulmonary lesions were artificially created in 4 canine models. All lung localization markers were precisely implanted with a median registration and implantation time of 6 minutes (range, 2–15 minutes). The average distance between pulmonary lesions and markers was 1.9±1.7 mm, based on computed tomography examination after localization. No severe pneumothorax was observed after marker implantation. After an average implantation period of 16.5 days, no marker displacement was observed.

Conclusions

The AR navigation-guided pulmonary nodule localization technique was safe and effective in a canine model. The validity and feasibility of using this technology in patients will be examined further (NCT04211051).

Improved visualization of virtual-assisted lung mapping by indocyanine green

Objectives

Virtual-assisted lung mapping (VAL-MAP) is a bronchoscopic marking method of dye application on the surface of the lungs before resecting nonpalpable nodules. However, in some cases, it can be difficult to identify the markings of VAL-MAP on computed tomography and intraoperative thoracoscopy. We developed and assessed the feasibility of indocyanine green VAL-MAP (ICG-VAL-MAP).

Methods

A historical control trial was conducted to investigate the effectiveness of ICG-VAL-MAP for marking visualization compared with that of VAL-MAP. In ICG-VAL-MAP, instead of indigo carmine, ICG and computed tomography contrast agents were used for dye marking, and near-infrared fluorescence endoscopy was employed to visualize the ICG markings. The other processes in VAL-MAP were carried out. The marking visibility was assessed in 3 grades of easy, faint, or not identifiable. We compared the visibility of the markings on computed tomography images and during thoracoscopic operations between VAL-MAP (567 markings in 147 cases) and ICG-VAL-MAP (142 markings in 63 cases).

Results

On the preoperative computed tomography images, ICG-VAL-MAP provided significantly better marking visualization than VAL-MAP (easy/faint/not identifiable = 142/0/0 vs 427/100/30; P < .0001). ICG-VAL-MAP provided significantly better intraoperative markings than VAL-MAP (easy/faint/not identifiable = 141/0/1, respectively, vs 475/50/42, respectively; P < .0001). Regarding complications, pneumothorax occurred in 8 (5.4%) cases of VAL-MAP and zero cases (0%) of ICG-VAL-MAP (P = .12); fever was observed in 7 (5.0%) cases of VAL-MAP and 2 (3.2%) cases of ICG-VAL-MAP (P = .72).

Conclusions

ICG-VAL-MAP provided significantly better visibility of markings than VAL-MAP. It might be useful in the resection of nonpalpable small lung lesions.

Role of a portable gamma-camera with optical view for margins assessment of pulmonary nodules resected by radioguided surgery

PURPOSE

Radioguided occult lesion localization (ROLL) of pulmonary nodules is an alternative to hook-wire. Both required of a histological margin assessment. The activity emerging from the radiotracer allows to obtain an intraoperative scintigraphic image of the surgical specimen by a portable gamma-camera (PGC) fitted with an optical view, which provides information about the localization of the nodule in relation to the margins. The aim of this study was to evaluate the intraoperative use of a PGC for margin assessment of pulmonary nodules.

METHODS

ROLL technique was used in 38 nodules (36 pulmonary, 1 chest wall, and 1 pleural nodules). A PGC intraoperative image of the surgical specimen was obtained in 32. Scintigraphic results were compared to the histological assessment. Other factors, such as nodule size, distance from the pleural surface, or distance covered by the needle, were considered as possible factors for non-centered lesions.

RESULTS

PGC images showed that the lesion was in contact with the margins in 8/32 cases and centered in 24. In all cases in which the lesion was considered as centered by the PGC, the margins were free of involvement (NPV 100%), although the PPV is low.

CONCLUSIONS

The use of a PGC for margin assessment after pulmonary nodule resection is feasible and provides a high NPV in our series. In addition, the short intraoperative time required for its use makes the PGC a useful tool for providing supplementary information to histopathologic results. Further studies from different surgical teams are required for an external validation.

Computer tomography guided thoracoscopic resection of small pulmonary nodules in the hybrid theatre

Purpose

Thoracic surgeons are currently asked to resect smaller and deeper lesions which are difficult to detect thoracoscopically. The growing number of those lesions arises both from lung cancer screening programs and from follow-up of extrathoracic malignancies. This study analyzed the routine use of a CT-aided thoracoscopic approach to small pulmonary nodules in the hybrid theatre and the resulting changes in the treatment pathway.

Methods

50 patients were retrospectively included. The clinical indication for histological diagnosis was suspected metastasis in 46 patients. Technically, the radiological distance between the periphery of the lesion and the visceral pleura had to exceed the maximum diameter of the lesion for the patient to be included. A spiral wire was placed using intraoperative CT-based laser navigation to guide the thoracoscopic resection.

Results

The mean diameter of the lesions was 8.4 mm (SD 4.27 mm). 29.4 minutes (SD 28.5) were required on average for the wire placement and 42.3 minutes (SD 20.1) for the resection of the lesion. Histopathology confirmed the expected diagnosis in 30 of 52 lesions. In the remaining 22 lesions, 9 cases of primary lung cancer were detected while 12 patients showed a benign disease.

Conclusion

Computer tomography assisted thoracoscopic surgery (CATS) enabled successful resection in all cases with minimal morbidity. The histological diagnosis led to a treatment change in 42% of the patients. The hybrid-CATS technique provides good access to deeply located small pulmonary nodules and could be particularly valuable in the emerging setting of lung cancer screening.

Fluorescent and Iodized Emulsion for Preoperative Localization of Pulmonary Nodules

OBJECTIVE

This study was conducted to develop a fluorescent iodized emulsion comprising indocyanine green (ICG) solution and lipiodol (ethiodized oil) and evaluate its feasibility for use in a clinical setting.

BACKGROUND

ICG use for the preoperative localization of pulmonary nodules is limited in terms of penetration depth and diffusion.

METHODS

First, fluorescent microscopy was used to investigate the distribution of ICG-lipiodol emulsions prepared using different methods. The emulsions were injected in 15 lung lobes of 3 rabbits under computed tomography fluoroscopy guidance; evaluation with imaging and radiography was conducted after thoracotomy. Subsequently, the emulsions were used to preoperatively localize 29 pulmonary nodules in 24 human subjects, and wedge resections were performed using fluorescent imaging and C-arm fluoroscopy.

RESULTS

The optimal emulsion of 10% ICG and 90% lipiodol mixed through 90 passages had even distribution and the highest signal intensity under fluorescent microscopy; it also had the best consistency in the rabbit lungs, which persisted for 24 hours at the injection site. In human subjects, the mean diameter of pulmonary nodules was 0.9 ± 0.4 cm, and depth from the pleura was 1.2 ± 0.8 cm. All emulsion types injected were well localized around the target nodules without any side effects or procedure-related complications. Wedge resection with minimally invasive approach was successful in all pulmonary nodules with a free resection margin.

CONCLUSIONS

A fluorescent iodized emulsion prepared by mixing ICG with lipiodol enabled accurate localization and resection of pulmonary nodules.

Carbohydrate based biomarkers enable hybrid near infrared fluorescence and 64Cu based radio-guidance for improved surgical precision

Increasing numbers of lung tumors are identified at early disease stages by diagnostic imaging in screening programs, but difficulties in locating these during surgical intervention has prevented an improved treatment outcome. Surgical biomarkers that are visible on diagnostic images, and that provide the surgeon with real-time image guidance during the intervention are thus highly warranted to bridge diagnostic precision into enhanced therapeutic outcome. In this paper, a liquid soft tissue marker for near infrared fluorescence and radio-guidance is presented. The biocompatible marker is based on the carbohydrate ester, sucrose acetate isobutyrate, ethanol, and a multifunctional naphthalocyanine dye, which enable near infrared fluorescence image-guided resection at short, medium and long tissue depths. Naphthalocyanine dyes have high quantum yields and may further act as chelators of radionuclides. Upon injection of the liquid marker, a gel-like depot is formed in situ at the site of injection, wherein the fluorescent dye and radionuclide is retained. The radiolabeled markers were optimized for minimal fluorescence quenching and high retention of the positron emission tomography radionuclide ⁶⁴Cu. The performance of the radiolabeled marker was tested in vivo in mice, where it displayed high photostability over a period of 4 weeks, and high retention of ⁶⁴Cu for 48 hours. The retention and biodistribution of ⁶⁴Cu was quantified via PET/CT, and the fluorescence emission by an in vivo imaging system. The presented data demonstrate proof-of-concept for naphthalocyanine markers as multimodal imaging agents that can bridge the precision of diagnostic imaging into surgical interventions.

Current trends in thoracic surgery

Thoracic surgery has evolved drastically in recent years. Although thoracic surgeons mainly deal with tumorous lesion in the lungs, mediastinum, and pleura, they also perform lung transplantation surgery in patients with end-stage lung disease. Herein, we introduce various major current topics in thoracic surgery. Minimally invasive surgical procedures include robot-assisted thoracic surgery and uniportal video-assisted thoracic surgery. Novel techniques for sublobar resection include virtual-assisted lung mapping, image-guided video-assisted thoracic surgery, and segmentectomy using indocyanine green. Three-dimensional (3D) computed tomography (CT) simulation consists of surgeon-friendly 3D-CT image analysis systems and new-generation, dynamic 3D-CT imaging systems. Updates in cadaveric lung transplantation include use of marginal donors, including donation after circulatory death, and ex vivo lung perfusion for such donors. Topics in living donor lobar lung transplantation include size matching, donor issues, and new surgical techniques. During routine clinical practice, thoracic surgeons encounter various pivotal topics related to thoracic surgery, which are described in this report.

Computed Tomography-Guided Methylene Blue Localization: Single vs. Multiple Lung Nodules

Background: Preoperative localization for small invisible and impalpable pulmonary nodules is important in single-port video-assisted thoracoscopic surgery (VATS). Localization of multiple pulmonary nodules during VATS resection remains challenging. The aim of our study is to elucidate the efficacy of preoperative CT-guided methylene blue localization of both single and multiple pulmonary nodules.

Methods: Consecutive patients undergoing preoperative CT-guided methylene blue dye localization for lung nodules, followed by VATS resection, were retrospectively analyzed between January 2014 and November 2019. Chi-square tests, Fisher's exact test and independent T-test were used to compare variables between the groups. Logistic regression was used to identify risk factors for procedure-related complications.

Results: A total of 388 patients, including 337 with single nodule and 51 with multiple nodules, were analyzed. The success rate of preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules were comparable as 98.8% (333/337) vs. 100% (108/108). The procedure time was longer (23.2 ± 9.4 vs. 7.6 ± 4.8 min, p < 0.001) and risk of pneumothorax was higher (47.1 vs. 25.5%, p = 0.002) in the multiple nodule group. The procedure time (OR 1.079; 95% CI = 1.041–1.118; p < 0.001) was an independent risk factor for pneumothorax. Nodule depth (OR 2.829; 95% CI = 1.259–6.356; p = 0.011) was an independent risk factor for pulmonary hemorrhage.

Conclusions: Preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules is safe, feasible, and effective.

The efficacy of transbronchial indocyanine green instillation for fluorescent-guided wedge resection

 

OBJECTIVES

The purpose of this study was to investigate the feasibility of lung wedge resection by combining 3-dimensional (3D) image analysis with transbronchial indocyanine green (ICG) instillation, in order to delineate the intended area for resection.

METHODS

From December 2017 to July 2020, 28 patients undergoing wedge resection (17 primary lung cancers, 11 metastatic lung tumours) were enrolled, and fluorescence-guided wedge resection was attempted. Virtual sublobar resections were created preoperatively for each patient using a 3D Image Analyzer. Surgical margins were measured in each sublobar resection simulation in order to select the most optimal surgical resection area. After transbronchial instillation of ICG, near-infrared thoracoscopic visualization allowed matching of the intended area for resection to the virtual sublobar resection area. To investigate the effectiveness of ICG instillation, the clarity of the ICG-florescent border was evaluated, and the distance from the true tumour to the surgical margins was compared to that of simulation.

RESULTS

Mean tumour diameter was 12.4 ± 4.3 mm. The entire targeted tumour was included in resected specimens of all patients (100% success rate). The shortest distances to the surgical margin via 3D simulation and by actual measurement of the specimen were11.4 ± 5.4 and 12.2 ± 4.1 mm, respectively (P = 0.285) and were well correlated (R2 = 0.437). While all specimens had negative malignant cells at the surgical margins, one loco-regional recurrence was observed secondary to the dissemination of neuroendocrine carcinoma.

CONCLUSIONS

ICG-guided lung wedge resection after transbronchial ICG instillation and preoperative 3D image analysis allow for adequate negative surgical margins, providing decreased risk of local recurrence.

The accuracy of cone-beam computed tomography and augmented fluoroscopy-guided bronchoscopic marking of multiple small-sized pulmonary nodules in a hybrid operating room: a retrospective cohort study

Background

For the minimally invasive excision of small-sized pulmonary nodules, bronchoscopic markings are increasingly being performed owing to advancements in video-assisted thoracic surgery (VATS). Hybrid operating room equipment is utilized for bronchoscopic VATS markings. We aimed to compare the marking accuracy between bronchoscopic VATS and other marking techniques such as computed tomography-guided percutaneous marking and conventional X-ray fluoroscopy-guided bronchoscopic marking.

Methods

Patients with small-sized pulmonary nodules scheduled to undergo VATS were enrolled in the study. A mixture of 50 to 100 µL of diluted indocyanine green and iopamidol was injected adjacent to the pulmonary nodules as a VATS marker. Patients receiving each of the three image-guided techniques were categorized into group A (computed tomography-guided percutaneous injection), group B (X-ray fluoroscopy-guided virtual bronchoscopy-assisted bronchoscope injection), and group C (cone-beam computed tomography and augmented fluoroscopy-guided virtual bronchoscope-assisted bronchoscopic injection in the hybrid operating room). VATS marking accuracy and procedural complications were compared among the three groups.

Results

In total, 61 patients with 73 pulmonary nodules were eligible for analysis. VATS marking was successful for 15/16 nodules in group A, 28/30 nodules in group B, and 25/27 nodules in group C. Marking accuracy was 5.75±4.59, 15.00±14.02, and 6.05±6.11 (mm), respectively. Multiple markings were successful in 0/1 (0%), 5/6 (83.3%), and 5/5 (100.0%) nodules in groups A, B, and C, respectively. A small pneumothorax occurred in 3/15 (20.0%) patients in group A.

Conclusions

The cone-beam computed tomography and augmented fluoroscopy-guided bronchoscopic approach performed in a hybrid operating room is accurate and equivalent to the computed tomography-guided percutaneous approach, and it enables the VATS marking of multiple pulmonary nodules without causing a secondary pneumothorax.

CT-guided color marking of impalpable pulmonary nodules prior to video-assisted thoracoscopic surgery

OBJECTIVES

To investigate the utility and complications of computed tomography (CT)-guided color marking of impalpable pulmonary nodules for video-assisted thoracoscopic surgical resection.

METHODS

This retrospective single institutional study has obtained Institutional Review Board approval. A total of 174 patients with 207 undiagnosed peripheral lesions of the lung were enrolled who had undergone preoperative computed tomography-guided color marking using colored collagen followed by video-assisted thoracoscopic surgery (VATS) from December 2015 to September 2018.

RESULTS

All nodules (mean 14.0 mm, range 3.0-30.0 mm) were successfully marked by computed tomography-guided color marking, and 96.0% cases (167/174) were localized by means of intraoperative fluoroscopy as clear spots. Minor pneumothorax with a median volume of 3.8 mL (range 0.2-119.0 mL) occurred in 12 patients (6.9%) who were completely asymptomatic and were not in serious condition. No patient required a chest tube. No major bleeding complication occurred, and no air emboli were seen. No intra- or post-operative mortality of VATS was observed.

CONCLUSIONS

Preoperative CT-guided color marking of impalpable pulmonary nodules is a safe and effective procedure that allows for successful surgical resection.

Electromagnetic navigation bronchoscopic localization versus percutaneous CT-guided localization for thoracoscopic resection of small pulmonary nodules

BACKGROUND

Identification of small pulmonary nodules is challenging in a limited intrathoracic field during minimally invasive video-assisted thoracoscopic surgery (VATS), and preoperative localization is required. Various techniques have been reported with some failure and complications. Here, we compare the feasibility and safety between electromagnetic navigation bronchoscopic marking and computed tomography (CT)-guided percutaneous marking using indocyanine green (ICG) and iopamidol.

METHODS

A total of 47 patients with small-sized pulmonary nodules, scheduled to undergo video-assisted thoracoscopic limited resection, were enrolled in this study. A mixture of diluted ICG and iopamidol was injected into the lung parenchyma as a marker, using CT-guided percutaneous or electromagnetic navigation bronchoscopic injection techniques and the results were examined and compared.

RESULTS

A total of 35 and 12 patients underwent preoperative marking by percutaneous injection and electromagnetic navigation bronchoscopic injection, respectively, in which a marker was detected in 33/35 (94.3%) and 12/12 (100%) patients. No combination of these procedures was performed in any patient. All markers were successfully detected in three patients who underwent injection marking at two different lesion sites. Pneumothorax occurred in five patients (14%) in the percutaneous marking group, which was relieved in all patients without the necessity for chest tube drainage. No other complication was observed in this study.

CONCLUSIONS

Electromagnetic navigation bronchoscopic injection techniques using indocyanine green fluorescence plus iopamidol are safe and effective, and comparable with CT-guided localization. Furthermore, a bronchoscopic approach enables marking of multiple lesion areas without increasing patient risk, especially for puncture-related pneumothorax.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Either computed tomography (CT)-guided percutaneous or electromagnetic navigation bronchoscopic injection techniques can be used for preoperative marking of pulmonary nodules with indocyanine green (ICG) fluorescence.

WHAT THIS STUDY ADDS

Indocyanine green (ICG) is a safe and easily detectable fluorescent marker for video-assisted thoracoscopic surgery (VATS). A bronchoscopic injection approach enables marking of multiple lesion areas without increasing the risk of pneumothorax.

In situ tissue pathology from spatially encoded mass spectrometry classifiers visualized in real time through augmented reality

Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data. Spatially encoded pathology classifications are displayed at the site of laser sampling as color-coded pixels in an augmented reality video feed of the surgical field of view. This is enabled by two-way communication between surgical navigation and mass spectrometry data analysis platforms through a custom-built interface. Performance of the system was evaluated using murine models of human cancers sampled in situ in the presence of body fluids with a technical pixel error of 1.0 ± 0.2 mm, suggesting a 84% or 92% (excluding one outlier) cancer type classification rate across different molecular models that distinguish cell-lines of each class of breast, brain, head and neck murine models. Further, through end-point immunohistochemical staining for DNA damage, cell death and neuronal viability, spatially encoded PIRL-MS sampling is shown to produce classifiable mass spectral data from living murine brain tissue, with levels of neuronal damage that are comparable to those induced by a surgical scalpel. This highlights the potential of spatially encoded PIRL-MS analysis for in vivo use during neurosurgical applications of cancer type determination or point-sampling in vivo tissue during tumor bed examination to assess cancer removal. The interface developed herein for the analysis and the display of spatially encoded PIRL-MS data can be adapted to other hand-held mass spectrometry analysis probes currently available.

Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data.

Photoacoustic imaging to localize indeterminate pulmonary nodules: A preclinical study

PURPOSE

Diagnosis and resection of indeterminate pulmonary nodules (IPNs) is a growing challenge with increased utilization of chest computed tomography. Photoacoustic (PA) -guided surgical resection with local injection of indocyanine green (ICG) may have utility for IPNs that are suspicious for lung cancer. This preclinical study explores the potential of PA imaging (PAI) to detect ICG-labeled tumors.

MATERIALS AND METHODS

ICG uptake by H460 lung cancer cells was evaluated in vitro. A phantom study was performed to analyze PA signal intensity according to ICG concentration and tissue thickness/depth using chicken breast. PA signals were measured up to 48 hours after injection of ICG (mixed with 5% agar) into healthy subcutaneous tissue, subcutaneous H460 tumors and right healthy lung in nude mice.

RESULTS

Intracellular ICG fluorescence was detected in H460 cells co-incubated with ICG in vitro. The concentration dependence of the PA signal was logarithmic, and PA signal decline was exponential with increasing tissue depth. The PA signal of 2 mg/mL ICG was still detectable at a depth of 22 mm in chicken breast. The PA signal from ICG mixed with agar was detectable 48 hours post injection into subcutaneous tissue and subcutaneous H460 tumors in nude mice. Similar features of PA signals from ICG-agar in mice lung were obtained.

CONCLUSION

The results from this preclinical study suggests that PAI of injected ICG-agar may be beneficial for identifying deeply located tumors. These features may be valuable for IPNs.

[Clinical Application of Vectorial Localization of Peripheral Pulmonary Nodules Guided by Electromagnetic Navigation Bronchoscopy in Thoracic Surgery]

背景与目的

随着计算机断层扫描技术（computed tomography scans, CT）的广泛应用，越来越多的肺小结节被发现，一些需要外科手术处理的结节数量也在增加。胸腔镜手术中对于不可直视及触摸到的肺外周小结节的准确定位较为困难。虽然目前一些常用的定位技术能够带来比较好的定位效果，如CT引导的穿刺定位和电磁导航支气管镜（electromagnetic navigation bronchoscopy, ENB）系统引导的亚甲兰染色定位，但同时仍存在着气胸、出血及定位不准确的问题。ENB引导的矢量定位法是我中心首创的一种新型定位技术，该技术避免了前两种

方法

可能出现的胸膜损伤或者定位区域扩大的问题，为ENB引导的定位技术提供了一定的指导。本文回顾性分析胸腔镜术前通过ENB引导矢量定位的临床结果来确定该方法的临床应用价值。方法回顾性分析2017年10月-2018年10月于青岛大学附属医院胸外科行ENB矢量定位法进行胸腔镜手术前定位的患者资料，统计患者临床资料、肺小结节影像学特征，评估该方法临床应用的安全性及有效性。

结果

我们成功实施了22例患者的22个肺外周结节在ENB引导下矢量定位和腔镜下楔形切除（22/22, 100%）。结节平均大小为（11.0±3.6）mm，距脏层胸膜表面距离为（16.5±6.2）mm；ENB系统显示屏导航定位装置（locatable guide, LG）与病灶距离为（14.5±10.1）mm，离体标本标记与病灶距离为（15.3±11.0）mm，ENB矢量定位平均时间为（17.5±4.2）min，无定位点LG发生移位（0.0%）。手术过程无中转开胸（0.0%），患者术中及术后未见明显并发症（0.0%），术后平均住院时间为（3.8±1.2）d，无围手术期患者死亡（0.0%）。术后病理结果为恶性肿瘤者19例，均得到了完全切除。

结论

我们应用ENB引导的矢量定位法在肺外周小结节术前定位和微创切除的初步经验提示该方法安全、可行、有效，可作为ENB操作中可选的一种定位方式。胸外科临床医师可以进一步研究该方法并应用到临床操作中。

Application of Fluorescent Dyes in Visceral Surgery: State of the Art and Future Perspectives

Background

Through the improvement and implementation of advanced intraoperative imaging, the indications for intraoperative fluorescence have spread to various fields of visceral surgery. Indocyanine green (ICG)-based fluorescence angiography and the imaging systems using this certain dye are currently the cornerstone of intraoperative, fluorescence-based medical imaging.

Summary

The article focuses on principles and approaches of intraoperative fluorescence in general surgery. The current clinical practice of intraoperative fluorescence and its evidence are described. Emerging new fields of application are put in a perspective. Furthermore, the technique and possible pit-falls in the performance of intraoperative ICG fluorescence angiography are described in this review article.

Key Messages

Overall growing evidence suggests that intraoperative fluorescence imaging delivers valuable additional information to the surgeon, which might help to perform surgery more exactly and reduce perioperative complications. Perfusion assessment can be a helpful tool when performing critical anastomoses. There is evidence from prospective and randomized trials for the benefit of intraoperative ICG fluorescence angiography during esophageal reconstruction, colorectal surgery, and surgery for mesenteric ischemia. Most studies suggest the administration of 2.5-10 mg of ICG. Standardized settings and documentation are essential. The benefit of ICG fluorescence imaging for gastrointestinal sentinel node detection and detection of liver tumors and colorectal metastases of the liver cannot clearly be estimated duo to the small number of prospective studies. Critical points in the use of intraoperative fluorescence imaging remain the low standardization and reproducibility of the results and the associated difficulty in comparing the results of the existing trials. Furthermore, little is known about the influence of hemodynamic parameters on the quantitative assessment of ICG fluorescence during surgery.

The safety and feasibility of intraoperative near-infrared fluorescence imaging with indocyanine green in thoracoscopic sympathectomy for primary palmar hyperhidrosis

Background

We investigated the safety and feasibility of intraoperative near‐infrared (NIR) imaging using indocyanine green (ICG) during sympathectomy in the management of primary palmar hyperhidrosis (PPH).

Methods

We performed a retrospective review of 142 patients (ICG group) who underwent endoscopic thoracic sympathectomy (ETS) between February 2018 and April 2019. All patients received a 5 mg/kg infusion of ICG 24 hours preoperatively. The vital signs before and after ICG injection and adverse reactions were recorded. Meanwhile, 498 patients (Non‐ICG group) who underwent ETS by normal thoracoscopy during August 2017 to April 2019 were also reviewed to compare the abnormal white blood cell (WBC) counts, alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN), and creatinine (Cr) levels before and after operation between two groups.

Results

For ICG group, the vital signs including body temperature, heart rate and blood pressure before and after ICG injection were stable. There was no significant difference in the abnormal WBC counts, ALT, AST, BUN, and Cr levels before and after operation between two groups. Only one patient had mild adverse reaction (0.7%) after ICG injection. The visibility rate of all sympathetic ganglions was 96.7% (1369/1415). The visibility rate from T1 to T5 was 98.23% (278/283), 98.23% (278/283), 97.17% (275/283), 95.76% (271/283), and 94.35% (267/283), respectively. There was no significant difference in the visibility rate with regard to age, gender, height, weight, body mass index, and PPH grade.

Conclusions

NIR fluorescence imaging with ICG for identifying sympathetic ganglions is relatively safe and feasible.

Key points

• Significant findings of the study.

NIR fluorescence imaging with ICG for identifying sympathetic ganglions is relatively safe and feasible.

• What this study adds.

This technology may take the place of the rib‐oriented method as standard practice for the precise localization of sympathetic ganglions, and may improve the effect of sympathectomies.

Electromagnetic Navigation-Guided Preoperative Localization of Small Malignant Pulmonary Tumors

BACKGROUND

Thoracoscopic resection of small pulmonary nodules can be challenging, which highlights the importance of preoperative localization. We report our experience with electromagnetic navigation-guided localization.

METHODS

The clinical, radiographic, surgical, and pathologic data of patients who underwent electromagnetic navigation-guided preoperative localization for pulmonary tumors smaller than 2 cm were reviewed. Successful localization was defined as successful identification of target lesions during the thoracoscopic procedure without palpation.

RESULT

Included were 30 patients with 35 nodules. There were 31 transthoracic and 5 transbronchial approaches performed. One patient received both approaches for the same tumor, and 3 received both approaches for localization of multiple targets. The median nodule size was 1.0 cm (interquartile range [IQR], 0.8-1.2 cm), and the median distance from the pleural surface was 1.1 cm (IQR, 0.6-2.0 cm). The most commonly used marker for localization was dye (n = 18), followed by microcoils (n =15). In nodules located with microcoils, the median distance between the microcoil and nodule was 1 mm (IQR, 0-3 mm). There were no complications related to the localization procedure. Successful localization was achieved in 27 of 30 patients (90.0%) and in 32 of 35 nodules (91.4%). The pathologic diagnosis was primary pulmonary malignancy in 29 nodules and secondary pulmonary malignancy in 6.

CONCLUSIONS

Our experience with electromagnetic navigation-guided transbronchial and transthoracic preoperative localization of small, malignant pulmonary tumors shows this technique is feasible and appears to be a viable option for preoperative localization of pulmonary nodules that may be difficult to locate thoracoscopically.

Feasibility study of navigated endoscopy for the placement of high dose rate brachytherapy applicators in the esophagus and lung

PURPOSE

To evaluate the electromagnetic (EM) tracking of endoscopes and applicators as a method of positioning a high dose rate (HDR) luminal applicator.

METHOD

An anatomical phantom consisting of a rigid trachea and flexible esophagus was used to compare applicator placement measurements using EM tracking vs the traditional method using two-dimensional (2D) fluoroscopy and surface skin markers. The phantom included a tumor in the esophagus and several pairs of optically visible points inside the lumen that were used to simulate proximal and distal ends of tumors of varying lengths. The esophagus tumor and lung points were visible on a computed tomography (CT) image of the phantom, which was used as ground truth for the measurements. The EM tracking system was registered to the CT image using fiducial markers. A flexible endoscope was tracked using the EM system and the locations of the proximal and distal ends of the tumor identified and this position recorded. An EM-tracked applicator was then inserted and positioned relative to the tumor markings. The applicator path was mapped using the EM tracking. The gross tumor length (GTL) and the distance between the first dwell position and distal edge of tumor (offset) were measured using the EM tracking and 2D fluoroscopy methods and compared to the same measurements on the CT image.

RESULTS

The errors in GTL using EM tracking were on average -0.5 ± 1.7 mm and 0.7 ± 3.6 mm for esophagus and lung measurements, similar to errors measured using the 2D fluoroscopy method of -0.9 ± 1.2 mm and 3.4 ± 4.4 mm. Offset measurements were slightly larger while using EM tracking relative to the fluoroscopy method but these were not statistically significant.

CONCLUSIONS

Electromagnetic tracking for placement of lumen applicators is feasible and accurate. Tracking of the endoscope that is used to identify the proximal and distal ends of the tumor and of the applicator during insertion generates accurate three-dimensional measurements of the applicator path, GTL and offset. Guiding the placement of intraluminal applicators using EM navigation is potentially attractive for cases with complex insertions, such as those with nonlinear paths or multiple applicator insertions.

Clinical study of video-assisted thoracoscopic surgery wedge resection in early-stage lung cancer by tumor mapping with indocyanine green

Aim

This study aimed to assess the clinical effectiveness of video-assisted thoracoscopic surgery (VATS) in early-stage lung cancer by indocyanine green (ICG) for tumor mapping.

Material and methods

Thirty patients with early-stage lung cancer with peripheral nodules smaller than 2 cm scheduled for computed tomography (CT)-guided microcoil placement followed by ICG tumor mapping by VATS wedge resection were enrolled. After microcoil deployment, 100 to 150 ml of diluted ICG was injected percutaneously near the nodule. The nodule initially was localized solely by using a near-infrared ray (NIR) thoracoscope to visualize ICG fluorescence. Thoracoscopic instruments were used to determine the staple line. Wedge resection was performed after confirmation of the location of the microcoil using fluoroscopy and pathology results.

Results

Thirty patients underwent VATS resection. The median tumor size was 1.3 cm by CT. The median depth from the pleural surface was 1.7 cm (range: 0.5–3.8 cm). The median CT-guided intervention time was 25 min, and VATS procedural time was 50 min. ICG fluorescence was clearly identified in 30 of 30 patients (100%). The surgical margins were all negative on final pathology in all included cases. The final diagnoses were 30 primary lung cancers; none needed additional resection.

Conclusions

CT-guided percutaneous ICG injection and intraoperative NIR localization of small nodules are safe and feasible. These offer surgeons the ease of localization through direct indocyanine green fluorescence imaging without the use of fluoroscopy and may be a complementary technique to preoperative microcoil placement for nonvisible, nonpalpable intrapulmonary nodules.

Recent fluorescence imaging technology applications of indocyanine green in general thoracic surgery

Thoracic surgeons perform a wide variety of cancer operations, which are often associated with high morbidity and mortality. Thus, thoracic surgery involves many special challenges that require innovative solutions. The increased utilization of minimally invasive practices, poor overall cancer survival, and significant morbidity of critical operations remain key obstacles to overcome. Fluorescence imaging technology (FIT), involving the implementation of fluorescent dyes and imaging systems, is currently used as an adjunct for general thoracic surgery in many situations and includes sentinel lymph node mapping, pulmonary intersegmental plane identification, pulmonary nodule identification, pulmonary bullous lesion detection, evaluation of the anastomotic perfusion after tracheal surgery, and thoracic duct imaging for postoperative chylothorax. This technology enhances the surgeon's ability to perform operations, and has specific advantages. We review some of the key studies that demonstrate the applications of FIT in the field of general thoracic surgery, focusing on the use of indocyanine green.

Near-Infrared-Guided Pulmonary Segmentectomy After Endobronchial Indocyanine Green Injection

BACKGROUND

The aim of this study is to prospectively determine the feasibility and safety of near-infrared fluorescence-guided pulmonary segmentectomy after endobronchial indocyanine green (ICG) injection using virtual bronchoscopy.

METHODS

Fifteen patients who underwent pulmonary segmentectomy were prospectively enrolled. Using preoperative computed tomography datasets a bronchial road map was created to determine the bronchus for ICG injection. Immediately after intubation ICG was injected into the target bronchi using an ultrathin bronchoscope. During the operation a near-infrared thoracoscope was used to detect ICG fluorescence and determine the intersegmental plane. The assessment points were (1) whether the ICG demarcation lines corresponded to the intersegmental lines expected from the pulmonary veins, (2) whether it was possible for the planned segmentectomy to be completed by electrocautery and 1 or fewer uses of an automated suturing device according to the demarcation plane, (3) whether any surgical complications occurred intraoperatively or (4) in the 1 month after surgery, and (5) whether the target lesion was removed completely with sufficient surgical margin to evaluate the feasibility and safety of this procedure.

RESULTS

In 13 cases (87%) a segmentectomy was completed in the planned way with sufficient surgical margins. The failure in 2 cases was due to a technical issue in the bronchial injection. No complications developed intraoperatively. Recurrent air leakage occurred in 1 case. No procedure-related adverse event was noted postoperatively.

CONCLUSIONS

Near-infrared-guided pulmonary segmentectomy with endobronchial ICG injection using virtual bronchoscopy was safe and feasible, and minor technical revision can make this procedure more reliable.

Is the near-infrared fluorescence imaging with intravenous indocyanine green method for identifying the intersegmental plane concordant with the modified inflation-deflation method in lung segmentectomy?

OBJECTIVES

At present, the modified inflation-deflation method is accepted and widely used in the clinic, but the near-infrared (NIR) fluorescence imaging with intravenous indocyanine green (ICG) method can also delineate the intersegmental demarcation. However, whether the two methods identify that the intersegmental plane is concordant with each other and match the real intersegmental demarcation is still unknown.

METHODS

Between March 2019 to July 2019, 19 consecutive segmentectomies were performed, using both methods to delineate the intersegmental plane, in order to evaluate and verify whether the intersegmental plane results created by the two methods were concordant and matched the real intersegmental demarcation.

RESULTS

Segmentectomies were carried out using uniportal video-assisted thoracic surgery (UVATS) successfully with no intraoperative conversions or ICG-related complications and only three cases (15.8%) with postoperative complications related to the operation. The intersegmental plane generated by the NIR fluorescence imaging with intravenous ICG method was found to be totally concordant with the modified inflation-deflation method that was approaching the real intersegmental demarcation in all 19 cases.

CONCLUSIONS

Both methods revealed the intersegmental plane clearly, and the NIR fluorescence imaging with intravenous ICG method was found to be totally concordant with the modified inflation-deflation method, which is highly concordant with the real intersegmental demarcation. NIR fluorescence imaging with intravenous ICG method may be more popular because of its safety, efficiency, and less complicated restrictions, especially in patients with pulmonary emphysema. Low doses of ICG do not affect the rate of identification of the intersegmental plane and is safer from drug toxicology.

The Utility of Near-Infrared Fluorescence and Indocyanine Green During Robotic Pulmonary Resection

During minimally invasive pulmonary resection, it is often difficult to localize pulmonary nodules that are small (<2 cm), low-density/subsolid on imaging, or deep to the visceral pleura. The use of near-infrared fluorescence (NIF) imaging for localizing pulmonary nodules using indocyanine green (ICG) contrast is an emerging technology that is increasingly utilized during pulmonary resection. When administered via electromagnetic navigational bronchoscopy (ENB), ICG can accurately localize pulmonary nodules. When injected intravenously (IV), ICG can also help delineate the intersegmental plane. Research is ongoing regarding the utility of ICG for identification of the sentinel lymph node in lung cancer.

Placement of markers to assist minimally invasive resection of peripheral lung lesions

With development of lung cancer screening programs and increased utilization of radiographic imaging there is significantly higher detection of smaller lung nodules and subsolid lesions. These nodules could be malignant and pose a diagnostic challenge. Video-assisted thoracoscopic surgery and robotic-assisted thoracoscopic surgery (RATS) represent minimally invasive methods for tissue sampling. Intraoperative identification of these lesions maybe difficult, requiring marking prior to surgery. We review different techniques for the placement of markers to assist in the resection of peripheral lung lesions (PLL).

Preoperative CT versus intraoperative hybrid DynaCT imaging for localization of small pulmonary nodules: a randomized controlled trial

BACKGROUND

Localization of small and/or deep pulmonary nodules before thoracoscopic exploration is paramount to minimize the likelihood of unplanned conversion to thoracotomy. As far as the percutaneous approach is concerned, the most common workflow consists of preoperative computed tomography (POCT) imaging-guided tumor marking (performed in an interventional CT suite) followed by their removal in an operating room (OR). However, the advent of hybrid ORs has allowed intraoperative computed tomography (IOCT)-guided lesion localization. This single center, open-label, randomized, controlled clinical trial aims to compare the efficacy and safety of IOCT versus POCT.

METHODS/DESIGN

The study sample will consist of patients presenting with small and/or deep pulmonary nodules who will be randomly allocated to either POCT or IOCT. The time required to complete lesion localization will be the primary efficacy outcome. The following parameters will serve as secondary endpoints: rate of successful targeting during localization and in the operating field, time at risk, operating time, length of time under anesthesia, global OR utilization time, complication (pneumothorax and hemorrhage) rates, and radiation exposure.

DISCUSSION

Owing to the increased availability of HORs, our data will be crucial to clarify the feasibility and safety of IOCT versus the traditional POCT approach.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03395964 . Registered on October 8, 2018.

Efficiency of thoracoscopic palpation in localizing small pulmonary nodules

PURPOSE

The thoracoscopic localization of small and deep pulmonary nodules can be challenging. We conducted this study to evaluate the efficiency of thoracoscopic palpation in tumor detection.

METHODS

The subjects of this study were 229 patients with a collective 267 indeterminate pulmonary nodules ≤ 15 mm in diameter, in the outer third of the lung field. The nodules were localized by palpation using the forefinger or a metal suction probe. Based on the distance from the pleura-to-tumor size ratio (D/S), the nodules were classified into group A (D/S = 0), group B (0 < D/S ≤ 1), and group C (D/S > 1).

RESULTS

The median tumor diameter was 10 mm. All 267 nodules were palpable and resected with negative margins via thoracoscopic wedge resection. The majority of the deep nodules had no pleural change (11%, 86%, and 100% in groups A, B, and C, respectively; P < 0.01). The median margins were 15, 16, and 14 mm in groups A, B, and C, respectively. In four patients (1.5%) with relatively short margins (2-7 mm), an additional intraoperative wedge resection was performed.

CONCLUSION

Thoracoscopic palpation was effective for tumor detection when the nodules were located in the outer third of the lung.