Feasibility investigation of near-infrared fluorescence imaging with intravenous indocyanine green method in uniport video-assisted thoracoscopic anatomical segmentectomy for identifying the intersegmental boundary line

Application of uniportal video-assisted thoracoscopic surgery for segmentectomy in early-stage non-small cell lung cancer: A narrative review

Uniportal video-assisted thoracoscopic surgery (UVATS) segmentectomy has emerged as an effective approach for managing early-stage non-small-cell lung cancer (NSCLC). Compared to conventional open and thoracoscopic surgeries, this minimally invasive surgical technique offers multiple benefits, including reduced postoperative discomfort, shorter hospital stays, expedited recovery, fewer complications, and superior cosmetic outcomes. Particularly advantageous in preserving lung function, UVATS segmentectomy is a compelling option for patients with compromised lung capabilities or limited pulmonary reserve. Notably, it demonstrates promising oncological results in early-stage NSCLC, with long-term survival rates comparable to those of lobectomies. Skilled thoracic surgeons can ensure a safe and effective execution of UVATS despite the potential technical challenges posed by complex tumor locations that may hinder visibility and maneuverability within the thoracic cavity. This study provided a comprehensive review of the literature and existing studies on UVATS segmentectomies. It delves into the evolution of the technique, its current applications, and the balance between its benefits and limitations. This discussion extends the technical considerations, challenges, and prospects of UVATS segmentectomy. Furthermore, it aimed to update advancements in segmentectomy for treating early-stage NSCLC, offering in-depth insights to thoracic surgeons to inform more scientifically grounded and patient-specific surgical decisions.

Impact of indocyanine green on prolonged air leak in minimally invasive segmentectomy

BACKGROUND

Video-assisted thoracoscopic segmentectomies have become the gold standard for the treatment of early-stage non-small cell lung cancer less than two centimeters. The main difficulty is the identification of intersegmental boundary lines which dictate postoperative morbidities.

METHODS

We conducted a retrospective study to compare the perioperative outcomes of patients who underwent minimally invasive segmentectomy using the traditional deflation-inflation method or the novel indocyanine green (ICG) technique. Using a prospectively maintained database, we performed a retrospective analysis of 197 consecutive anatomical segmentectomies, from 2020 to 2023. Clinical effectiveness, postoperative complications, and histological data were compared.

RESULTS

A total of 73 (37%) patients had the inflation-deflation method and 124 (63%) had the intravenous ICG method. There were no significant differences in chest tube duration, prolonged air leak, postoperative complications, and postoperative hospital stays. Surgical margin width was also similar between the two groups. The multivariable analysis confirmed these results. Lastly, intravenous ICG brought no additional value in complex segmentectomies.

CONCLUSION

This monocentric and retrospective analysis found no added value of the intravenous ICG on the perioperative results of minimally invasive segmentectomies. The place of this novel technique in the surgical armamentarium remains to be defined. Specific indications such as complex segmentectomy or patients with chronic pulmonary disease require further study.

The use of intravenous indocyanine green in minimally invasive segmental lung resections: a systematic review

Background

To identify intersegmental planes (ISPs) in video/robot-assisted thoracoscopic segmentectomies, indocyanine green (ICG) is commonly used. The aim of this systematic review is to evaluate the efficacy of intravenous ICG in the identification of ISP.

Methods

A systematic search was performed. Studies evaluating patients who underwent a video/robot-assisted thoracoscopic segmentectomy using intravenous ICG were included. The primary outcome measure was the frequency and percentage of patients in whom the ISP was adequately visualized. Secondary outcomes encompassed the ICG dose, time to visualization, time to maximum ICG visualization, time to disappearance of ICG effect and adverse reactions to ICG.

Results

Eighteen studies were included for systematic review, enrolling a total of 1,090 patients. Irrespective of the injected dose, intravenous ICG identified the ISP in 94% of the cases (range, 30-100%). Overall, there was a considerable amount of heterogeneity regarding the injected dose of ICG (range, 5-25 mg or 0.05-0.5 mg/kg). The mean time before first effect of ICG was visible ranged from 10 to 40 seconds. The mean total time of ICG visibility ranged from 90 to 140 seconds after a bolus injection and was 170 seconds after continuous infusion. No adverse reactions were reported.

Conclusions

After administration of intravenous ICG, visualization of the ISP is successful in up to 94% of cases, even after administration of a low dose (0.05 mg/kg) of ICG. The use of intravenous ICG is safe with no reported adverse effects in the immediate peri-operative period.

Robot-assisted segmentectomy with improved modified inflation-deflation combined with the intravenous indocyanine green method

To investigate the perioperative outcomes of patients who underwent robot-assisted thoracoscopic (RATS) segmentectomy for identifying the intersegmental plane (ISP) by improved modified inflation-deflation (MID) combined with near-infrared fluorescence imaging with the intravenous indocyanine green (ICG) method and to assess the feasibility of this method in a large-scale cohort according to the type of segmentectomy performed. We retrospectively analysed the perioperative data of a total of 155 consecutive patients who underwent RATS segmentectomy between April 2020 and December 2021. Data from the operation, including the demarcation status of the intersegmental plane, were analysed retrospectively. The mean operative time and estimated blood loss were 125.56 ± 36.32 min and 41.81 ± 49.18 mL, respectively. Good demarcation of the intersegmental plane was observed in 150 (96.77%) patients, with no correlation with the type of resected segments or the surgical method. Postoperative complications of Clavien-Dindo classification grade 3 or more were observed in 4 patients (2.58%), and no ICG-related adverse events were noted. Demarcation of the intersegmental plane by improved MID combined with ICG is feasible regardless of the type of segmentectomy and can be commonly applied in robot-assisted segmentectomy.

"Separated" precise subsegmentectomy: Single-port thoracoscopic noncombined subsegmentectomy in one lung lobe

BACKGROUND

In clinical practice, combined segmental resection (CSS) can avoid resection of multiple segments to preserve lung function. When two or more distant lung segments or subsegments of the same lobe present with a ground glass opacity (GGO) that meets the indications for sublobar resection, conventional CSS or wedge resection could not remove all the nodules, and lobectomy is performed in most of these patients. For these particular types of nodules, we perform a single lobe noncombined subsegmental resection, or "separated" precise subsegmentectomy, to preserve more lung tissue. This study was designed to initially assess the feasibility and safety of "separated" precise subsegmentectomy.

METHODS

Selected cases of specific GGO were subjected to "separated" precise subsegmentectomy and the results of general clinical data, perioperative operative time, bleeding, length of stay, computed tomography (CT) review, lung function and its dynamic changes were collected and analyzed in these patients.

RESULTS

"Separated" precise subsegmentectomy was performed in 12 patients and successfully completed. The median operation time, bleeding amount, and length of hospital stay were 96 min, 50 ml and 4 days, respectively. There was one case of pulmonary infection and one case of persistent air leakage, no death or pulmonary torsion, bronchopleural fistula and other pulmonary complications occurred. After 3 months, the median percentage of lung function retention was 91.7%, and the CT scan showed that the reserved lung tissue of 12 patients was well inflated and there was no obvious imaging manifestation of atelectasis.

CONCLUSION

"Separated" precise subsegmentectomy is a novel and safe surgical method that provides a more optimized way for patients with specific multiple nodules to preserve lung function. Further prospective large studies are needed to verify this finding.

Identification of the intersegmental plane by arterial ligation method during thoracoscopic segmentectomy

Background

Thoracoscopic segmentectomy is a common surgical procedure in thoracic surgery today. However, identifying the intersegmental plane is difficult in the surgical process. Therefore, we evaluated the feasibility of the arterial ligation method for determining the intersegmental plane and compared the demarcation status with the intravenous indocyanine green (ICG).

Methods

We retrospectively reviewed the records of 35 patients with peripheral small lung nodules who underwent thoracoscopic segmentectomy between May and December 2020. First, the preoperative three-dimensional reconstruction was performed to distinguish the location of lung nodules and the anatomical structures of targeted segmental arteries, veins, and bronchi. Second, the targeted segmental arteries were ligated, and the intersegmental plane was determined by the inflation-deflation technique. The waiting time for the appearance of the inflation-deflation line was recorded. Thirdly, the intersegmental plane was identified again using the ICG fluorescence method. Finally, the consistency of the two intersegmental planes was evaluated.

Results

The intersegmental planes were successfully observed in all patients using the arterial ligation method. Thirty-four patients underwent segmentectomy as planned, and one patient finally underwent lobectomy due to insufficient surgical margin. The waiting time for the appearance of the intersegmental plane by arterial ligation method was 13.7 ± 3.2 min (6–19 min). The intersegmental planes determined by the arterial ligation method and the ICG fluorescence method were comparable, with a maximum distance of no more than 5 mm between the two planes. The mean operative duration was 119.1 ± 34.9 min, and the mean blood loss was 76.9 ± 70.3 ml. No evident air leakage was found during the operation. Only one patient experienced a prolonged air leak (≥ 5 days) during the postoperative recovery. No atelectasis occurred in all cases. The chest tube duration was 3.1 ± 0.9 days.

Conclusion

The arterial ligation method can efficiently and accurately identify the intersegmental plane, comparable to the ICG fluorescence method.

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.

Comparative study of a modified double-lumen tube ventilation control connector and traditional connector in clinical use: a randomised-controlled trial

Background

A Y-shaped rotatable connector (YRC) for double-lumen tubes (DLT) is invented and compared with the traditional connector (Y-shaped connector, YC).

Methods

Sixty patients with ASA grade I-III, aged ≥ 18 years, who needed to insert a DLT for thoracic surgery were recruited and assigned into the YRC group (n = 30) and the YC group (n = 30) randomly. The primary endpoints included the inhaled air concentration (Fi) and the exhaled air concentration (Et) of sevoflurane before and after the switch between two-lung ventilation and one-lung ventilation at different times, positioning time, and switching time. The secondary endpoints were the internal gas volume of the two connectors, airway pressure, and the sputum suction time.

Results

The Et and Fi of the YRC group and the YC group were significantly different (all p < 0.05) at 5s, 10s, and 30s after the patient switched from two-lung ventilation to one-lung ventilation. The positioning time of the YRC group was less than YC group (89.75 ± 14.28 s vs 107.80 ± 14.96 s, p < 0.05), as well as the switching time (3.60 ± 1.20 s vs 9.05 ± 2.53 s, p < 0.05) and the internal gas volume (17.20 ml vs 24.12 ml). There was no difference in airway pressure and the sputum suction time in two groups.

Conclusion

Compared with YC, YRC was beneficial for maintaining depth of anesthesia, improves efficiency for the switch between one-lung and two-lung ventilation, and shortens the tube positioning time.

1. YRC was beneficial to maintain the stability of anesthesia depth.

2. YRC improves the conversion efficiency for one-lung and two-lung ventilation.

3. YRC shortens the positioning time.

Near-infrared fluorescence guided surgery: State of the evidence from a health technology assessment perspective

Different applications of near-infrared fluorescence-guided surgery are very promising, and techniques that help surgeons in intraoperative guidance have been developed, thereby bridging the gap between preoperative imaging and intraoperative visualization and palpation. Thus, these techniques are advantageous in terms of being faster, safer, less invasive, and cheaper. There are a few fluorescent dyes available, but the most commonly used dye is indocyanine green. It can be used in its natural form, but different nanocapsulated and targeted modifications are possible, making this dye more stable and specific. A new active tumor-targeting strategy is the conjugation of indocyanine green nanoparticles with antibodies, making this dye targeted and highly selective to various tumor proteins. In this mini-review, we discuss the application of near-infrared fluorescence-guided techniques in thoracic surgery. During lung surgery, it can help find small, non-palpable, or additional tumor nodules, it is also useful for finding the sentinel lymph node and identifying the proper intersegmental plane for segmentectomies. Furthermore, it can help visualize the thoracic duct, smaller bullae of the lung, phrenic nerve, or pleural nodules. We summarize current applications and provide a framework for future applications and development.

Real-time image-guided indocyanine green fluorescence dual-visualization technique to measure the intraoperative resection margin during thoracoscopic segmentectomy

AIMS

The primary goal of thoracoscopic segmentectomy is the complete resection of early pulmonary carcinoma while sparing as much of the normal pulmonary parenchyma as possible, but an obvious trade-off exists between the pulmonary parenchymal preservation and an adequate resection margin. In this clinical trial, we explored a real-time image-guided indocyanine green (ICG) fluorescence dual-visualization technique to confirm the resection margin by improving the intraoperative localization of the pulmonary nodule and identification of the intersegmental boundary line (IBL).

METHODS

This study was utilized in 35 patients with a screening-detected lung nodule <2 cm to complete thoracoscopic segmentectomy from December 2020 to June 2021. Computed tomography-guided localization of the pulmonary nodule with ICG solution was performed on the day of surgery. During the surgery, after dissecting the targeted pulmonary segmental arteries, ICG at 5 mg/body was injected into the systemic vein.

RESULTS

We observed no toxicity. The dual-visualization technique was successfully implemented in all 35 patients to achieve a negative resection margin, which was more than 2 (mean 2.71 ± 0.59) cm, or the size of the tumor based on the final pathological examinations. No intraoperative complications occurred and only one patient had postoperative prolonged air leaks, which was ceased 8 days later after conservative management without reoperation.

CONCLUSIONS

This method is a safe and feasible alternative to ensure a negative resection margin without removing an unreasonable amount of pulmonary parenchyma during pulmonary segmentectomy. Future studies will be needed to compare this method to alternative techniques in a clinical trial.

Feasibility investigation of near-infrared fluorescence imaging with intravenous indocyanine green method in uniport video-assisted thoracoscopic anatomical segmentectomy for identifying the intersegmental boundary line

OBJECTIVES

To investigate the perioperative outcomes of patients who underwent uniport video-assisted thoracoscopic (VATS) segmentectomy for identifying the intersegmental boundary line (IBL) by the near-infrared fluorescence imaging with the intravenous indocyanine green (ICG) method or the modified inflation-deflation (MID) method and assess the feasibility and effectiveness of the ICG fluorescence (ICGF)-based method.

METHODS

We retrospectively analyzed the perioperative data in total 198 consecutive patients who underwent uniport VATS segmentectomy between February 2018 and August 2020. With the guidance of a preoperative imaging interpretation and analysis system (IQQA-3D), the targeted segment structures could be precisely identified and dissected, and then the IBL was confirmed by the ICGF-based method or the MID method. The clinical effectiveness and postoperative complications of the two methods were evaluated.

RESULTS

An IBL was visible in 98% of patients in the ICGF-based group, even with low doses of ICG. The ICGF-based group was significantly associated with a shorter IBL clear presentation time (23.6 ± 4.4 vs. 23.6 ± 4.4 s) (p < 0.01) and operative time (89.3 ± 31.6 vs. 112.9 ± 33.3 min) (p < 0.01) compared to the MID group. The incidence of postoperative prolonged air leaks was higher in the MID group than in the ICGF-based group (8/100, 8% vs. 26/98, 26.5%, p = 0.025). There were no significant differences in bleeding volume, chest tube duration, postoperative hospital stays, surgical margin width, and other postoperative complications.

CONCLUSION

The ICGF-based method could highly accurately identify the IBL and make anatomical segmentectomy easier and faster, and therefore has the potential to be a feasible and effective technique to facilitate the quality of uniport VATS segmentectomy.