Precise Anatomical Sublobar Resection Using a 3D Medical Image Analyzer and Fluorescence-Guided Surgery With Transbronchial Instillation of Indocyanine Green

Identification of the Separation Range of an Incomplete Interlobar Fissure in Segmentectomy Using Near Infrared

In segmentectomy for patients with incomplete interlobar fissures, insufficient dissection of the interlobar parenchyma may result in incomplete segmentectomy, while excessive dissection may lead to excessive bleeding and air leaks. Here, we report a case of left apicoposterior (S¹⁺²) segmentectomy with incomplete interlobar fissure in which near-infrared thoracoscopy with indocyanine green was used to identify the separation range of interlobar fissure by dissecting the relevant vessels beforehand.

Use of Indocyanine Green Fluorescence Imaging in Thoracic and Esophageal Surgery

BACKGROUND

Fluorescence imaging using indocyanine green in thoracic and esophageal surgery is gaining popularity because of the potential to facilitate surgical planning, to stage disease, and to reduce postoperative complications. To optimize use of fluorescence imaging in thoracic and esophageal surgery, an expert panel sought to establish a set of recommendations at a consensus meeting.

METHODS

The panel included 12 experts in thoracic and upper gastrointestinal surgery from Asia-Pacific countries. Before meeting, 7 focus areas were defined: intersegmental plane identification for sublobar resections; pulmonary nodule localization; lung tumor detection; bullous lesion detection; lymphatic mapping of lung tumors; evaluation of gastric conduit perfusion; and lymphatic mapping in esophageal surgical procedures. A literature search of the PubMed database was conducted using keywords indocyanine green, fluorescence, thoracic, surgery, and esophagectomy. At the meeting, panelists addressed each focus area by discussing the most relevant evidence and their clinical experiences. Consensus statements were derived from the proceedings, followed by further discussions, revisions, finalization, and unanimous agreement. Each statement was assigned a level of evidence and a grade of recommendation.

RESULTS

A total of 9 consensus recommendations were established. Identification of the intersegmental plane for sublobar resections, localization of pulmonary nodules, lymphatic mapping in lung tumors, and assessment of gastric conduit perfusion were applications of fluorescence imaging that have the most robust current evidence.

CONCLUSIONS

Based on best available evidence and expert opinions, these consensus recommendations may facilitate thoracic and esophageal surgery using fluorescence imaging.

Use of a radiofrequency identification system for precise sublobar resection of small lung cancers

BACKGROUND

The incidence of sublobar resection is increasing because of the rise in the detection of small lung cancers. However, local recurrence needs to be addressed, and several methods are needed for the resection with secure margins of non-visible and non-palpable tumors.

METHODS

We retrospectively reviewed the use of a radiofrequency identification (RFID) system in sublobar resection of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) at our institute.

RESULTS

From June 2020 to June 2022, 39 patients underwent sublobar resection for AIS or MIA. The median age was 69 years (interquartile range, 64-76). Among the 39 patients, 24 were diagnosed with AIS and 15 with MIA. Segmentectomy, subsegmentectomy, and wedge resection were performed in nine, six, and 24 patients, respectively. The median size of the target tumor was 9.0 mm (8.1-12.9) and the median distance between the tag and the tumor was 2.9 mm (0-7.5). The median pathological surgical margin was 15.0 mm (10-17.5). Complete resection of all lesions was performed with a secure surgical margin. The median follow-up duration was 6 months, during which no local recurrence was detected in any of the patients.

CONCLUSIONS

The RFID marking system accurately informed the surgeons of the tumor location and helped them to perform precise sublobar resection.

Significance of the evaluation of tracheal length using a three-dimensional imaging workstation

BACKGROUND

Limited information is available on the total tracheal length and its other characteristics for tracheal surgery. This study aimed to investigate the reference value of tracheal length and assess its relationship with physiological variables.

METHODS

We measured the tracheal length of 215 patients (107 men and 108 women) who underwent contrast-enhanced computed tomography before thoracic surgery using a three-dimensional imaging workstation. Pearson correlation analysis and multiple linear regression analysis were performed to investigate the relationship between the total tracheal length (cervical and thoracic) and common physiological parameters.

RESULTS

The mean total tracheal length was 11.5±1 cm (range, 8.8-14.4 cm); 8% of the patients had a total tracheal length <10 cm. The cervical trachea was significantly shorter in men than in women (2.9±1.3 vs. 3.8±1.3 cm, P<0.001), whereas the thoracic trachea was significantly longer in men than in women (8.9±1.1 vs. 7.4±1.1 cm, P<0.001). Correlation analysis showed that the total tracheal length was positively associated with height in both sexes, while the height was positively associated with only cervical tracheal length. In the multiple linear regression analysis, the total tracheal length was influenced most by height, while cervical and thoracic tracheal lengths were influenced most by sex. Older age was also an independent contributor to a shorter cervical trachea and longer thoracic trachea in both sexes.

CONCLUSIONS

The total tracheal length ranged from short to long in individuals, and characteristics of tracheal length varied with height, age, sex, and part of the trachea. We should thus be aware of the tracheal length of each patient for appropriate tracheal management.

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.

Extended, virtual and augmented reality in thoracic surgery: a systematic review

OBJECTIVES

Extended reality (XR), encompassing both virtual reality (VR) and augmented reality, allows the user to interact with a computer-generated environment based on reality. In essence, the immersive nature of VR and augmented reality technology has been warmly welcomed in all aspects of medicine, gradually becoming increasingly feasible to incorporate into everyday practice. In recent years, XR has become increasingly adopted in thoracic surgery, although the extent of its applications is unclear. Here, we aim to review the current applications of XR in thoracic surgery.

METHODS

A systematic database search was conducted of original articles that explored the use of VR and/or augmented reality in thoracic surgery in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to December 2020.

RESULTS

Our search yielded 1494 citations, of which 21 studies published from 2007 to 2019 were included in this review. Three main areas were identified: (i) the application of XR in thoracic surgery training; (ii) preoperative planning of thoracic procedures; and (iii) intraoperative assistance. Overall, XR could produce progression along the learning curve, enabling trainees to reach acceptable standards before performing in the operating theatre. Preoperatively, through the generation of 3D-renderings of the thoracic cavity and lung anatomy, VR increases procedural accuracy and surgical confidence through familiarization of the patient's anatomy. XR-assisted surgery may have therapeutic use particularly for complex cases, where conventional methods would yield inadequate outcomes due to inferior accuracy.

CONCLUSION

XR represents a salient step towards improving thoracic surgical training, as well as enhancing preoperative planning and intraoperative guidance.

Thoracoscopic complex basilar segmentectomies: an analysis of 63 procedures

Background

Thoracoscopic complex basilar segmentectomies are technically demanding and challenging. We review our experience to check whether this complexity can lead to specific surgical issues or increased post-operative morbidity.

Methods

Complex basilar segmentectomies were defined as the anatomical resection of at least one segment composing the basilar pyramid, excluding S⁶. Data of patients who had an intention-to-treat thoracoscopic complex basilar segmentectomy were retrospectively collected from 2007 to 2019: indications, preoperative assessment, clinical features, operative technical aspects and early post-operative outcome.

Results

Sixty-three patients, 26 men (41%) and 37 women (59%) with a median age of 66 years and a median body mass index (BMI) of 26 kg/m2 were included. Interventions performed were mostly S⁹⁺¹⁰ (n=32) and S⁸ (n=12) segmentectomies. Forty-five planned operations (71%) were completed. Extension to a larger resection was necessary in 17 patients (27%) and 4 patients underwent conversion to open surgery (6%). Median operative time was 168 minutes with a median intraoperative bleeding of 30 mL. Complications occurred in 11 patients (17%). There was no mortality. Median length of pleural drainage was 2 days (range, 1–2 days) and median hospital stay 4 days.

Conclusions

The extension rate of complex basilar segmentectomy is higher than that of other sublobar resections but their post-operative morbidity is identical.

Fluorescence visualization of the intersegmental plane by bronchoscopic instillation of indocyanine green into the targeted segmental bronchus: determination of the optimal settings

Objective

To determine the appropriate amount of indocyanine green for bronchial insufflation.

Methods

We enrolled 20 consecutive patients scheduled for anatomical segmentectomy in the Kochi Medical School Hospital. After inducing general anesthesia, 6 to 60 mL of 200-fold-diluted indocyanine green (0.0125 mg/mL) was insufflated into the subsegmental bronchi in the targeted pulmonary segmental bronchus. The volume of the targeted pulmonary segments was calculated using preoperative computed tomography. Fluorescence spread in the segmental alveoli was visualized using a dedicated near-infrared thoracoscope.

Results

The targeted segment was uniformly visualized by indocyanine green fluorescence in 16/20 (80.0%) cases after insufflating indocyanine green. A receiver operating characteristic curve indicated that the area under the curve was 0.984; the optimal cut-off volume of diluted indocyanine green for insufflation was 8.91% of the calculated targeted pulmonary segment volume.

Conclusions

The setting for indocyanine green insufflation was optimized for near-infrared fluorescence image-guided anatomical segmentectomy. By injecting the correct amount of indocyanine green, fluorescence-guided anatomical segmentation may be performed more appropriately.

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.

Combination of nitrous oxide and the modified inflation-deflation method for identifying the intersegmental plane in segmentectomy: A randomized controlled trial

Background

During thoracoscopic segmentectomy, accurately and rapidly identifying the intersegmental plane (ISP) is of great importance. This study aimed to investigate the effect and safety of a nitrous oxide (N₂O)/oxygen (O₂) inspired mixture on the appearance time of the ISP (T_ISP) via the modified inflation‐deflation method.

Methods

A total of 65 participants who underwent segmentectomy were randomized into three groups: 75% N₂O (n = 24), 50% N₂O (n = 23) or 0% N₂O (n = 18). The 75% N₂O group received a gas mixture of N₂O/O₂ (Fio₂ = 0.25), the 50% N₂O group received N₂O/O₂ (Fio₂ = 0.5), and the 0% N₂O group received 100% oxygen during lung expansion. The appearance time of satisfactory and ideal planes was recorded. Furthermore, arterial blood gas at breathing room air, one‐lung ventilation (OLV) before lung expansion, 5 and 15 min after lung expansion were also recorded.

Results

T_ISP was significantly shorter in the 75% N₂O group (320.2 ± 65.9 s) compared with that of the 50% N₂O group (552.4 ± 88.9 s, p < 0.001) and the 0% N₂O group (968.3 ± 85.5 s, p < 0.001), while the 50% N₂O group was shorter than that of the 0% N₂O group (p < 0.001). Arterial oxygenation was significantly improved in the 0% N₂O group only after lung expansion, before which there were no differences in mean PaO₂ values among groups.

Conclusions

The use of N₂O in the inspired gas mixture during lung expansion is an applicable strategy to rapidly identify the ISP via the modified inflation‐deflation method without any adverse effect on OLV related arterial oxygenation during segmentectomy.

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.

Comparison of surgical outcomes between thoracoscopic anatomical sublobar resection including and excluding subsegmentectomy

OBJECTIVES

Despite the ubiquitous utilization of anatomical sublobar resection for malignant lung tumors, the effectiveness and feasibility of subsegmentectomy remains unclear. This study therefore compared the perioperative outcomes between anatomical sublobar resection including (IS) and excluding (ES) subsegmentectomy.

METHODS

Patients who had undergone anatomical sublobar resection at our institution from January 2013 to March 2019 were retrospectively reviewed. Clinicopathologic characteristics and perioperative outcomes of the IS group (n = 58) were then analyzed the compared to those of the ES group (n = 203).

RESULTS

No statistically significant differences in age, sex, comorbidities, tumor location, preoperative pulmonary function, or tumor size on imaging were found between both groups. The IS group had significantly higher preoperative computed tomography-guided marking rates (40% vs. 18%; p < 0.01) and used significantly more staplers for intersegmental dissection than the ES group [4, interquartile range (IQR): 3-4 vs. 3, IQR: 3-4; p = 0.03]. Both groups had comparable 30-day mortality (0% vs. 0%; p > 0.99), intraoperative complications (7% vs. 10%; p = 0.61), and postoperative complications (5% vs. 8%; p = 0.58). After propensity score matching, the IS group experienced significantly lesser blood loss than the ES group (5 mL, IQR: 1-10 vs. 5 mL, IQR: 5-20; p = 0.03). Both groups experienced no local recurrence and demonstrated similar postoperative pulmonary functions after surgery.

CONCLUSIONS

IS may be a feasible and acceptable therapeutic option for malignant lung tumors. Nonetheless, future investigations are required to further validate the current findings.

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.