Using novel technology to augment complex video-assisted thoracoscopic single basilar segmentectomy

Novel locally nebulized indocyanine green for simultaneous identification of tumor margin and intersegmental plane

BACKGROUND

Segmentectomy, recommended for early-stage lung cancer or compromised lung function, demands precise tumor detection and intersegmental plane identification. While indocyanine green (ICG) commonly aids in these aspects using near-infrared imaging, its separate administrations through different routes and times can lead to complications and patient anxiety. This study aims to develop a lung-specific delivery method by nebulizing low-dose ICG to targeted lung segments, allowing simultaneous detection of lung tumors and intersegmental planes across diverse animal models.

METHODS

To optimizing the dose of ICG for lung tumor and interlobar fissure detection, different doses of ICG (0.25, 0.1, and 0.05 mg/kg) were nebulized to rabbit lung tumor models. The distribution of locally nebulized ICG in targeted segments was studied to evaluate the feasibility of detecting lung tumor and intersegmental planes in canine lung pseudotumor models.

RESULTS

Near-infrared fluorescence imaging demonstrated clear visualization of lung tumor margin and interlobar fissure using local nebulization of 0.1 mg/kg ICG for only 4 min during surgery in the rabbit models. In the canine model, the local nebulization of 0.05 mg/kg of ICG into the target segment enabled clear visualization of pseudotumor and intersegmental planes for 30 min.

CONCLUSIONS

This innovative approach achieves a reduction in ICG dose and prolonged the visualization time of the intersegmental plane and effectively eliminates the need for the hurried marking of tumors and intersegmental planes. The authors anticipate that lung-specific delivery of ICG will prove valuable for image-guided limited resection of lung tumors in clinical practice.

Precise and safe pulmonary segmentectomy enabled by visualizing cancer margins with dual-channel near-infrared fluorescence

BACKGROUND

Segmentectomy is a type of limited resection surgery indicated for patients with very early-stage lung cancer or compromised function because it can improve quality of life with minimal removal of normal tissue. For segmentectomy, an accurate detection of the tumor with simultaneous identification of the lung intersegment plane is critical. However, it is not easy to identify both during surgery. Here, the authors report dual-channel image-guided lung cancer surgery using renally clearable and physiochemically stable targeted fluorophores to visualize the tumor and intersegmental plane distinctly with different colors; cRGD-ZW800 (800 nm channel) targets tumors specifically, and ZW700 (700 nm channel) simultaneously helps discriminate segmental planes.

METHODS

The near-infrared (NIR) fluorophores with 700 nm and with 800 nm channels were developed and evaluated the feasibility of dual-channel fluorescence imaging of lung tumors and intersegmental lines simultaneously in mouse, rabbit, and canine animal models. Expression levels of integrin αvβ3, which is targeted by cRGD-ZW800-PEG, were retrospectively studied in the lung tissue of 61 patients who underwent lung cancer surgery.

RESULTS

cRGD-ZW800-PEG has clinically useful optical properties and outperforms the FDA-approved NIR fluorophore indocyanine green and serum unstable cRGD-ZW800-1 in multiple animal models of lung cancer. Combined with the blood-pooling agent ZW700-1C, cRGD-ZW800-PEG permits dual-channel NIR fluorescence imaging for intraoperative identification of lung segment lines and tumor margins with different colors simultaneously and accurately.

CONCLUSION

This dual-channel image-guided surgery enables complete tumor resection with adequate negative margins that can reduce the recurrence rate and increase the survival rate of lung cancer patients.

Simultaneous Visualization of Lung Tumor and Intersegmental Plane during Pulmonary Segmentectomy by Intravenous Injection of Indocyanine Green

Segmentectomy is a targeted surgical approach tailored for patients with compromised health and early-stage lung cancer. The key to successful segmentectomy lies in precisely identifying the tumor and intersegmental planes to ensure adequate resection margins. In this study, we aimed to enhance this process by simultaneously visualizing the tumor and intersegmental planes through the intravenous injection of indocyanine green (ICG) at different time points and doses. Lung tumors were detected by intravenous injection of ICG at a dose of 2 mg/kg 12 h before surgery in a rabbit model. Following the dissection of the pulmonary artery, vein, and bronchi of the target segment, 0.6 mg/kg of ICG was injected intravenously to detect the intersegmental plan. Fluorescent images of the lung tumors and segments were acquired, and the fluorescent signal was quantified using the signal-to-background ratio (SBR). Finally, a pilot study of this method was conducted in three patients with lung cancer. In a preclinical study, the SBR of the tumor (4.4 ± 0.1) and nontargeted segments (10.5 ± 0.8) were significantly higher than that of the targeted segment (1.6 ± 0.2) (targeted segment vs. nontarget segment, p < 0.0001; target segment vs. tumor, p < 0.01). Consistent with preclinical results, lung tumors and the intersegmental plane were successfully detected in patients with lung cancer. Consequently, adequate resection margins were identified during the surgery, and segmentectomy was successfully performed in patients with lung cancer. This study is the first to use intravenous ICG injections at different time points and doses to simultaneously detect lung cancer and intersegmental planes, thereby achieving segmentectomy for lung cancer.

Anatomic evaluation of Pancoast tumors using three-dimensional models for surgical strategy development

OBJECTIVE

Pancoast tumor resection planning requires precise interpretation of 2-dimensional images. We hypothesized that patient-specific 3-dimensional reconstructions, providing intuitive views of anatomy, would enable superior anatomic assessment.

METHODS

Cross-sectional images from 9 patients with representative Pancoast tumors, selected from an institutional database, were randomly assigned to presentation as 2-dimensional images, 3-dimensional virtual reconstruction, or 3-dimensional physical reconstruction. Thoracic surgeons (n = 15) completed questionnaires on the tumor extent and a zone-based algorithmic surgical approach for each patient. Responses were compared with surgical pathology, documented surgical approach, and the optimal "zone-specific" approach. A 5-point Likert scale assessed participants' opinions regarding data presentation and potential benefits of patient-specific 3-dimensional models.

RESULTS

Identification of tumor invasion of segmented neurovascular structures was more accurate with 3-dimensional physical reconstruction (2-dimensional 65.56%, 3-dimensional virtual reconstruction 58.52%, 3-dimensional physical reconstruction 87.50%, P < .001); there was no difference for unsegmented structures. Classification of assessed zonal invasion was better with 3-dimensional physical reconstruction (2-dimensional 67.41%, 3-dimensional virtual reconstruction 77.04%, 3-dimensional physical reconstruction 86.67%; P = .001). However, selected surgical approaches were often discordant from documented (2-dimensional 23.81%, 3-dimensional virtual reconstruction 42.86%, 3-dimensional physical reconstruction 45.24%, P = .084) and "zone-specific" approaches (2-dimensional 33.33%, 3-dimensional virtual reconstruction 42.86%, 3-dimensional physical reconstruction 45.24%, P = .501). All surgeons agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction benefit surgical planning. Most surgeons (14/15) agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction would facilitate patient and interdisciplinary communication. Finally, most surgeons (14/15) agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction's benefits outweighed potential delays in care for model construction.

CONCLUSIONS

Although a consistent effect on surgical strategy was not identified, patient-specific 3-dimensional Pancoast tumor models provided accurate and user-friendly overviews of critical thoracic structures with perceived benefits for surgeons' clinical practices.

Technical aspects and early results of uniportal video-assisted thoracoscopic complex segmentectomy: a 30 case-series study

Background

With the advantages of better cosmetic incision and faster recovery, uniportal video-assisted thoracoscopic surgery (UP-VATS) has developed rapidly worldwide in recent decades, and indications for UP-VATS have been further expanded to those for conventional VATS. Complex segmentectomy that makes several or intricate intersegmental planes, with more complex procedures, continues to be difficult in minimally invasive techniques. However, there are few reports on UP-VATS complex segmentectomy. In this report, we describe the perioperative clinical data and operative techniques and present our early results of UP-VATS complex segmentectomy in our hospital.

Methods

The records of a total of 30 patients who underwent UP-VATS complex segmentectomy by a single surgeon between January 2021 and June 2021 were retrospectively reviewed. We defined cases as complex segmentectomy if they required resection of segments 9 and 10, combined segmentectomy, segmentectomy + subsegmentectomy, subsegmentectomy, or combined subsegmentectomy.

Results

The mean age was 52.8 ± 9.9 years old; the mean nodule size was 0.84 ± 0.36 cm; the mean margin width was 2.307 ± 0.309 cm; the median operative time was 229.0 ± 58.06 min; the mean operative hemorrhage was 56.60 ± 17.95 mL; 5.58 ± 1.74 lymph nodes dissected had not metastasized; the mean duration of postoperative chest tube drainage was 4.7 ± 1.4 days; and the mean postoperative hospital stay was 6.5 ± 3.0 days. Although 1 patient experienced a prolonged air leak, the other 29 recovered uneventfully. Another patient failed to reach the 2-cm safe margins and subsequently underwent completion lobectomy.

Conclusions

UP-VATS complex segmentectomy is a safe and effective procedure in the treatment of lung cancers, sparing more pulmonary parenchyma and ensuring safe margins, with the disadvantage being the lengthy operative times during early skill acquisition.

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.

Technical Advances in Segmentectomy for Lung Cancer: A Minimally Invasive Strategy for Deep, Small, and Impalpable Tumors

With the increased detection of early-stage lung cancer and the technical advancement of minimally invasive surgery (MIS) in the field of thoracic surgery, lung segmentectomy using MIS, including video- and robot-assisted thoracic surgery, has been widely adopted. However, lung segmentectomy can be technically challenging for thoracic surgeons due to (1) complex segmental and subsegmental anatomy with frequent anomalies, and (2) difficulty in localizing deep, small, and impalpable tumors, leading to difficulty in obtaining adequate margins. In this review, we summarize the published evidence and discuss key issues related to MIS segmentectomy, focusing on preoperative planning/simulation and intraoperative tumor localization. We also demonstrate two of our techniques: (1) three-dimensional computed tomography (3DCT)-based resection planning using a novel 3DCT processing software, and (2) tumor localization using a novel radiofrequency identification technology.

Prognosis of segmentectomy in the treatment of stage IA non-small cell lung cancer

With improvements in detection technology, increasing numbers of patients with non-small cell lung cancer (NSCLC) are being diagnosed at an early stage. In order to treat the illness with minimal invasion and preserve lung function to the greatest possible extent, there has been an increasing tendency towards treating early-stage NSCLC by segmentectomy. However, questions remain regarding whether patients may benefit from this procedure considering the surgical and oncological outcomes. Whether adequate margin distance and lymph node dissection may be achieved is one of the most important issues associated with this procedure. The present study reviews the prognosis of segmentectomy in the treatment of stage IA NSCLC.

Multi-Wavelength Fluorescence in Image-Guided Surgery, Clinical Feasibility and Future Perspectives

With the rise of fluorescence-guided surgery, it has become evident that different types of fluorescence signals can provide value in the surgical setting. Hereby a different range of targets have been pursued in a great variety of surgical indications. One of the future challenges lies in combining complementary fluorescent readouts during one and the same surgical procedure, so-called multi-wavelength fluorescence guidance. In this review we summarize the current clinical state-of-the-art in multi-wavelength fluorescence guidance, basic technical concepts, possible future extensions of existing clinical indications and impact that the technology can bring to clinical care.

Concepts and techniques: how to determine and identify the appropriate target segment in anatomical pulmonary segmentectomy?

Anatomical segmentectomy is gathering increasing interest among thoracic surgeons because of increased detection of pulmonary nodules with ground-glass opacity (GGO) as well as an increase in the number of compromised patients. Accurate determination of intersegmental planes is a challenge in anatomical segmentectomy, and multiple methods have been proposed including developing inflation/deflation lines and injecting indocyanine green either intravenously or intrabronchially. Considering resection margins, adding a localization technique to conventional methods, or conducting virtual-assisted lung mapping (bronchoscopic multi-spot dye marking) may be an optional approach for optimal anatomical segmentectomy to identify intersegmental planes and obtain adequate resection margins. To determine optimal resection lines in anatomical segmentectomy, surgeons must also consider oncological validity such as venous and lymph drainage, resection margins, and lung anatomy to avoid complications such as venous congestion, infarction, and air leakage. Although anatomical segmentectomy is an attractive approach to resect small early-stage lung cancer and some metastatic lung tumors, caution is needed to optimally perform this technically demanding surgery.

Open insufflation: a novel technique for identifying the intersegmental border

Segmentectomy is gaining popularity for the treatment of lung cancer, especially in the early stages. Comprehensive understanding of segmental and subsegmental anatomy is required for the procedure to be successfully completed from a technical and oncological point of view. We hereby present a novel technique for delineating the intersegmental border, which can be widely reproduced because it is not time-consuming and does not require special equipment.