Usefulness of near-infrared angiography for identifying the intersegmental plane and vascular supply during video-assisted thoracoscopic segmentectomy

Near-Infrared Fluorescence Imaging with Intravenous Indocyanine Green Method in Segmentectomy for Infants with Congenital Pulmonary Airway Malformation

BACKGROUND

 Video-assisted thoracoscopic surgery is a commonly used procedure for treating congenital pulmonary airway malformation (CPAM) in infants, particularly when performing segmentectomy for segmental lesions. An innovative technique employing near-infrared fluorescence (NIRF) imaging with intravenous indocyanine green (ICG) has been utilized to delineate the intersegmental demarcation during surgery. However, no previous reports have investigated this method's application, specifically in infants. The primary aim of this study was to assess the safety and efficacy of the NIRF imaging with ICG approach in this context.

METHODS

 Between January 2021 and April 2022, a total of 19 consecutive segmentectomies were conducted using the NIRF imaging with ICG method to precisely identify the intersegmental plane. The results were concurrently compared with those obtained using the modified inflation-deflation technique. Comprehensive imaging and clinical data were gathered and analyzed to assess the safety and accuracy of the NIRF imaging with ICG approach.

RESULTS

 The study involved infants with a median age of 5.12 months (mean body weight of 8.08 g). All segmentectomies were performed successfully without any ICG-related complications. The mean operating time for the surgeries was 88.47 ± 7.94 minutes. Notably, no intraoperative conversions or significant complications were observed in any of the patients. The average hospital stay after surgery was 4.0 ± 0.82 days. During the follow-up period, extending beyond 1-year of postoperation, all patients exhibited excellent recovery with no cases of recurrence.

CONCLUSIONS

 Based on our experience, the NIRF imaging with intravenous ICG method proved to be both safe and effective when performing segmentectomy for infants with CPAM. Low doses of ICG did not hinder the accurate identification of the intersegmental plane.

Effect of transbronchial or intravenous administration of indocyanine green on resection margins during near-infrared-guided segmentectomy: a review

For early-stage non-small cell lung cancer, surgical resection remains the best treatment option. Currently, sublobar resection, including segmentectomy, is recommended in these cases, as it provides a better quality of life with the same oncological outcomes; however, is requires adequate resection margins. Accurate preoperative planning and proper identification of the intersegmental planes during thoracic surgery are crucial for ensuring precise surgical management and adequate resection margins. Three dimensional computed tomography reconstruction and near-infrared-guided intersegmental plane identification can greatly facilitate the surgical procedures. Three-dimensional computed tomography reconstruction can simulate both the resection and resection margins. Indocyanine green is one of the most frequently used and affordable fluorophores. There are two ways to identify the intersegmental planes using indocyanine green: intravenous and transbronchial administration. Intravenous application is simple; however, its effectiveness may be affected by underlying lung disease, and it requires the isolation of segmental structures before administration. Transbronchial use requires appropriate bronchoscopic skills and preoperative planning; however, it also allows for delineation deep in the parenchyma and can be used for complex segmentectomies. Both methods can be used to ensure adequate resection margins and, therefore, achieve the correct oncological radicality of the surgical procedure. Here, we summarise these applications and provide an overview of their different possibilities.

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.

Influencing Factors on Intersegmental Identification Adequacy in Segmentectomy with Intraoperative Indocyanine Green (ICG) Intravenous Administration

Accurate identification of the intersegmental plane is essential in segmentectomy, and Indocyanine Green (ICG) assists in visualizing lung segments. Various factors, including patient-related, intraoperative, and technical issues, can influence boundary delineation. This study aims to assess the rate of unsuccessful intersegmental identification and identify the contributing factors. We analyzed cases of lung segmentectomy from April 2020 to March 2023, where intraoperative ICG was intravenously administered during robot-assisted or video-assisted thoracoscopic surgery. Cases where fluorescence extended beyond expected boundaries within 30 s were classified as the "unclear boundary group". This group was then compared to the "clear boundary group". The study encompassed 111 cases, 104 (94%) of which were classified under the "clear boundary group" and 7 (6%) under the "unclear boundary group". The "unclear boundary group" had a significantly lower DLCO (15.7 vs. 11.8, p = 0.03) and DLCO/VA (4.3 vs. 3.0, p = 0.01) compared to the "clear boundary group". All cases in the "unclear boundary group" underwent lower lobe segmentectomy. ICG administration effectively outlines pulmonary segments. Challenges in segment demarcation may occur in cases with low DLCO and DLCO/VA values, particularly during lower lobe segmentectomy.

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.

Hyperspectral imaging enables the differentiation of differentially inflated and perfused pulmonary tissue: a proof-of-concept study in pulmonary lobectomies for intersegmental plane mapping

OBJECTIVES

The identification of the intersegmental plane is a major interoperative challenges during pulmonary segmentectomies. The objective of this pilot study is to test the feasibility of lung perfusion assessment by Hyperspectral Imaging for identification of the intersegmental plane.

METHODS

A pilot study (clinicaltrials.org: NCT04784884) was conducted in patients with lung cancer. Measuring tissue oxygenation (StO₂; upper tissue perfusion), organ hemoglobin index (OHI), near-infrared index (NIR; deeper tissue perfusion) and tissue water index (TWI), the Hyperspectral Imaging measurements were carried out in inflated (P_vent) and deflated pulmonary lobes (P_nV) as well as in deflated pulmonary lobes with divided circulation (P_nVC) before dissection of the lobar bronchus.

RESULTS

A total of 341 measuring points were evaluated during pulmonary lobectomies. Pulmonary lobes showed a reduced StO2 (P_vent: 84.56% ± 3.92 vs. P_nV: 63.62% ± 11.62 vs. P_nVC: 39.20% ± 23.57; p<0.05) and NIR-perfusion (P_vent: 50.55 ± 5.62 vs. P_nV: 47.55 ± 3.38 vs. P_nVC: 27.60 ± 9.33; p<0.05). There were no differences of OHI and TWI between the three groups.

CONCLUSIONS

This pilot study demonstrates that HSI enables differentiation between different ventilated and perfused pulmonary tissue as a precondition for HSI segment mapping.

Dual Image Navigation to Secure Surgical Margins in Thoracoscopic Segmentectomy

PURPOSE

Video-assisted thoracoscopic surgery (VATS) segmentectomy is being increasingly used for the management of non-small cell lung cancer. For non-palpable lesions, surgeons frequently find difficulty in ensuring a sufficient surgical resection margin.

OBJECTIVE

The purpose of this study was to evaluate the role of intraoperative dual image navigation in combination with the infrared thoracoscopy with intravenous injection of indocyanine green (IRT-ICG) method and intraoperative computed tomography (CT) in detecting oncological margins.

METHODS

This study involved 34 consecutive patients who underwent both IRT-ICG and intraoperative CT-assisted thoracoscopic segmentectomy between October 2017 and July 2021. The intersegmental line on the visceral pleura was visualized using the IRT-ICG method. The intersegmental line was marked by clipping, and an intraoperative CT scan was performed under bilateral lung ventilation. Intraoperative CT or three-dimensional CT reconstruction images were used by surgeons to confirm the correct anatomic segmental border and to secure a sufficient resection margin.

RESULTS

A well-defined intersegmental line was observed in 91.2% of patients. In eight cases, the surgeon needed to make some modifications to the resection line to secure a sufficient surgical margin. The mean surgical margin assessed on gross examination by the pathologist was 23.4 ± 9.0 mm. Complete resection was achieved in all patients using this approach.

CONCLUSIONS

Intraoperative dual image navigation combined with the IRT-ICG method and intraoperative CT scan enables surgeons to perform definitive VATS segmentectomy for non-palpable lesions.

Comparison of various lung intersegmental plane identification methods

Keeping a sufficient surgical margin free of tumor is important to prevent local recurrence in lung segmentectomy. Accurate identification of the intersegmental plane is essential to achieve adequate surgical margins. Traditionally, the inflation-deflation method was used to identify the intersegmental plane. However, in recent years, various intersegmental plane identification methods, including systemic indocyanine green injection, have been reported and shown to be useful. The purpose of this review was to evaluate the identification rates, advantages, and disadvantages of various intersegmental identification methods in lung segmentectomy. There are primarily six methods: inflation-deflation method, selective segmental inflation, endobronchial dye injection, virtual-assisted lung mapping, systemic indocyanine green injection, and pure oxygen method. These are broadly classified into those that use bronchi and pulmonary arteries anatomically and those that use air and dye technically. In this review, all methods showed relatively high identification rates. Moreover, high identification rates were expected, especially with systemic indocyanine green injection and the pure oxygen method. Each method has its advantages and disadvantages as varying situations entail different methods. It is necessary to select and apply them effectively; therefore, further improvement for each method will be required in the future.

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.

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.

Characterization of Near-Infrared Imaging and Indocyanine-Green Use Amongst General Surgeons: A Survey of 263 General Surgeons

BACKGROUND

Near-infrared fluorescence imaging (NIRFI) is an increasingly utilized imaging modality, however its use amongst general surgeons and its barriers to adoption have not yet been characterized.

METHODS

This survey was sent to Canadian Association of General Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons members. Survey development occurred through consensus of NIRFI experienced surgeons.

RESULTS

Survey completion rate for those opening the email was 16.0% (n = 263). Most respondents had used NIRFI (n = 161, 61.2%). Training, higher volumes, and bariatric, thoracic, or foregut subspecialty were associated with use (P < .001).Common reasons for NIRFI included anastomotic assessment (n = 117, 72.7%), cholangiography (n = 106, 65.8%), macroscopic angiography (n = 66, 41.0%), and bowel viability assessment (n = 101, 62.7%). Technical knowledge, training and poor evidence were cited as common barriers to NIRFI adoption.

CONCLUSIONS

NIRFI use is common with high case volume, bariatric, foregut, and thoracic surgery practices associated with adoption. Barriers to use appear to be lack of awareness, low confidence in current evidence, and inadequate training. High quality randomized studies evaluating NIRFI are needed to improve confidence in current evidence; if deemed beneficial, training will be imperative for NIRFI adoption.

[Feasibility Investigation of Fluorescence Method in Uniport Thoracoscopic Anatomical Segmentectomy for Identifying the Intersegmental Boundary Line]

BACKGROUND

Segmentectomy has gradually become one of the standard surgical methods for small pulmonary nodules with early lung cancer on imaging. This study aimed to investigate the perioperative outcomes of patients who underwent uniport video-assisted thoracoscopic surgery (VATS) segmentectomy for identifying the intersegmental boundary line (IBL) by the near-infrared fluorescence imaging with 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 preoperative intelligent/interactive qualitative and quantitative analysis-three dimensional (IQQA-3D), the targeted segment structures could be precisely identified and dissected, and then the IBL was confirmed by ICGF-based method or MID method. Clinical effectiveness and postoperative complications of the two methods were evaluated.

RESULTS

An IBL was visible in 98% of patients by the ICGF-based group, even with the low-doses of ICG. The ICGF-based group was significantly associated with the shorter IBL clear presentation time [(23.59±4.47) s vs (1,026.80±318.34) s] (P<0.01) and operative time [(89.3±31.6) min 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 (8.0% vs 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 (P>0.05).

CONCLUSIONS

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.

The Role of Surgery in Lung Cancer Treatment: Present Indications and Future Perspectives-State of the Art

Non-small cell lung cancers (NSCLC) are different today, due to the increased use of screening programs and of innovative systemic therapies, leading to the diagnosis of earlier and pre-invasive tumors, and of more advanced and controlled metastatic tumors. Surgery for NSCLC remains the cornerstone treatment when it can be performed. The role of surgery and surgeons has also evolved because surgeons not only perform the initial curative lung cancer resection but they also accompany and follow-up patients from pre-operative rehabilitation, to treatment for recurrences. Surgery is personalized, according to cancer characteristics, including cancer extensions, from pre-invasive and local tumors to locally advanced, metastatic disease, or residual disease after medical treatment, anticipating recurrences, and patients' characteristics. Surgical management is constantly evolving to offer the best oncologic resection adapted to each NSCLC stage. Today, NSCLC can be considered as a chronic disease and surgery is a valuable tool for the diagnosis and treatment of recurrences, and in palliative conditions to relieve dyspnea and improve patients' comfort.

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.

Indocyanine green imaging for pulmonary segmentectomy

Objective

Delineation of the intersegmental plane during pulmonary segmentectomy by systemic injection of indocyanine green (ICG) has been rapidly emerging. We evaluated the feasibility of the use of ICG in a large-scale cohort according to the type of segmentectomy and the presence of obstructive lung disorder and compared the demarcation status with air injection.

Methods

We collected the data of 209 patients who underwent segmentectomy using ICG at National Cancer Center Hospital, Tokyo, Japan. Data of the operation including the demarcation status of the intersegmental plane were analyzed retrospectively.

Results

The median operation duration and blood loss were 105 minutes (interquartile range, 94-118 minutes) and 12 mL (interquartile range, 5-24 mL), respectively. Good demarcation of the intersegmental plane by ICG was observed in 184 (88.0%) cases, with no correlation to the type of resected segments or the presence of obstructive lung disorder. Postoperative complications of Clavien–Dindo classification grade 3 or more were observed in 5 cases (2.4%), and no ICG-related adverse event was noted. High-frequency jet ventilation was also used in 160 cases (76.6%) to delineate the intersegmental inflation–deflation plane. The air injected by high-frequency jet ventilation tended to spread further beyond the intersegmental plane that was depicted by ICG.

Conclusions

The use of ICG might demarcate the intersegmental plane more restricted to the target segment compared with air injection. Delineation of the intersegmental plane by ICG is feasible regardless of the type of segmentectomy or the presence of obstructive lung disorder, and it can be commonly applicable in pulmonary segmentectomy.

Near-infrared intraoperative imaging with indocyanine green is beneficial in video-assisted thoracoscopic segmentectomy for patients with chronic lung diseases: a retrospective single-center propensity-score matched analysis

OBJECTIVE

To investigate whether video-assisted thoracoscopic segmentectomy using near-infrared fluorescence imaging had better intersegmental plane visualization and peri-operative outcome in patients with chronic lung diseases.

METHODS

Data were collected retrospectively from March 2014 and August 2019. A total of 92 patients with pulmonary nodules underwent near-infrared fluorescence guided uni-port thoracoscopic segmentectomy(NIF-VATS), 149 patients underwent thoracoscopic segmentectomy with inflation-deflation method(ID-VATS). After 1:1 propensity matching, perioperative outcomes between NIF-VATS and ID-VATS was compared.

RESULTS

Incision size was 3 cm in both group.Mean operative time was 79 min in NIF-VATS group and 96 min in ID-VATS group. The intersegmental plane was not clear in 33 cases of ID-VATS group, and no clear boundary was found after prolonged waiting time. Emphysema or pulmonary bullae could be found in chest CT scan in these patients, they all were diagnosed as chronic obstructive pulmonary disease. In NIF-VATS group, the intersegmental plane was not clear in 8 cases. Under the guidance of three-dimensional reconstruction and preoperative positioning, the oncological margin length of both groups met the requirements of surgical quality control. The intraoperative blood loss, number of lymph node resection, showed no statistical difference between the two groups. Postoperative air leakage was more often observed in ID-VATS group. The postoperative drainage duration, postoperative hospitalization time was shorter in ID-VATS group.

CONCLUSIONS

Compared with inflation-deflation method, segmentectomy using NIF imaging is feasible for patients with chronic lung diseases with better intersegmental plane, shorter operation time, less complications, it might lead to faster recovery.

Identification of the intersegmental plane during thoracoscopic segmentectomy: state of the art

During thoracoscopic segmentectomy, where direct palpation of the tumour is not always possible, achieving adequate margins from the cancer is of crucial importance. It is thus mandatory to accurately identify the intersegmental plane (ISP). Indeed, inadequate determination and division of the ISP can lead to unsatisfactory oncological results. Our systematic review focused on the effectiveness of the different techniques for identifying the ISP, highlighting the fact that a 1-size-fits-all method is not feasible. Based on the published evidence, 6 main methods were reported, each with its pros and cons: inflation-deflation technique, selective resected segmental inflation, systemic injection of indocyanine green, injection of endobronchial dye, 3-dimensional simulation using multidetector computed tomography and virtual-assisted lung mapping. In conclusion, ISP demarcation is mandatory to achieve a high rate of success of thoracoscopic segmentectomy, and it is very helpful in surgical planning, especially when preoperative multidetector computed tomography and 3-dimensional reconstructions are routinely performed.

A method to identify pulmonary intersegmental planes with intravenous vitamin B2 injection

PURPOSE

The present study investigated whether the pulmonary intersegmental planes could be identified with the intravenous injection of vitamin B₂ using a fluorescent camera and whether this method can be used instead of the inflation-deflation technique or the intravenous indocyanine green (ICG) method.

METHODS

In experiment 1, the vitamin B₂ was intravenously injected to visualize the pulmonary intersegmental plane and perform segmentectomy, and the visualized pulmonary intersegmental line was then compared to the inflation-deflation line in six pigs. In experiment 2, using six pigs, the fluorescent area and duration of fluorescence were compared after the intravenous injection of vitamin B₂ and ICG in the same animals.

RESULTS

In all animals in experiment 1, it was possible to clearly detect yellow-green fluorescence in the lung, in segments other than the one intended for resection, for at least 60 min. Moreover, the line visualized with vitamin B₂ fluorescence matched the inflation-deflation line in all animals. In experiment 2, the area of vitamin B₂ fluorescence corresponded to the area of ICG fluorescence in each animal.

CONCLUSIONS

The visualization of fluorescence after the intravenous injection of vitamin B₂ using a fluorescent camera was a simple, safe, and accurate method for detecting intersegmental planes in a pig model. This method can be an alternative to the inflation-deflation technique and the intravenous ICG method.

Constant-rate intravenous infusion of indocyanine green leading to high fluorescence intensity in infrared thoracoscopic segmentectomy

Objectives

The purpose of this study was to determine whether or not fluorescence could be increased by administering indocyanine green at a constant rate, thus stabilizing its blood concentration.

Methods

In 20 consecutive patients undergoing segmentectomy, the dominant pulmonary arteries were ligated, blocking blood in the target segment. Fluorescence intensity was then observed using different indocyanine green administration methods under infrared thoracoscopy. Intravenous administration of indocyanine green, via a syringe pump at a rate of 12.5 mg/min, was defined as the constant rate group. The bolus group was defined by a 5-mg indocyanine green rapid intravenous injection. The fluorescence intensity was compared at the time of maximum fluorescence and 2 minutes after fluorescence initiation.

Results

At maximum staining, the fluorescence intensity of the normal blood flow area was brighter in the constant rate group (median, 184.2; interquartile range, 170.2-200.1) compared with the bolus group (median, 122.3; interquartile range, 87.3-144.7; P = .0003). The fluorescence of the normal blood flow was retained even after 2 minutes. There was no difference in the fluorescence intensity of the ischemic segments.

Conclusions

The constant rate method showed brighter and better fluorescence than the bolus injection, without an increase in the dose. The contrast between adjacent segments was clear, facilitating the differentiation of the areas.

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.

Impact of complex segmentectomies by video-assisted thoracic surgery on peri-operative outcomes

Background

Pulmonary segmentectomies are generally classified into simple (tri-segmentectomy or lingulectomy as well as apical or basilar segmentectomy) and complex (individual or bi-segmentectomy of the upper, middle and lower lobes). Complex segmentectomies are technically feasible by video-assisted thoracic surgery (VATS) but remain challenging, and reports on post-operative outcomes are scarce. This study analyzes the differences between simple and complex VATS segmentectomy in terms of peri- and post-operative outcomes.

Methods

We retrospectively reviewed records of all patients who underwent anatomical pulmonary segmentectomy by VATS from 2014 to 2018 in two university hospitals.

Results

A total of 232 patients (114 men; median age 67 years; range, 29-87 years) underwent VATS segmentectomy for primary lung cancer (n=177), metastases (n=26) and benign lesions (n=29). The overall 30-day mortality and morbidity rates were 0.8% and 29.7%, respectively. The re-operation rate was 4.7%. Complex segmentectomy was realized in 111 patients including 86 (77.5%) upper lobe segmentectomies and 44 (39.6%) bi-segmentectomies. There was no statistical difference between complex and simple segmentectomy in terms of operative time (145 vs. 143 min, respectively; P=0.79) and chest tube duration [median: 1 (range, 0-33) vs. 2 (range, 1-19) days, respectively; P=0.95]. Post-operative overall complication rates were similar for both groups (30% vs. 30%, respectively; P=0.99) and were not correlated with the type of segmentectomy. However, complex segmentectomy patients had a shorter length of hospitalization compared to simple segmentectomy patients [median: 5 (range, 1-36) vs. 7 (range, 2-31) days; P=0.026]. Interestingly, complex segmentectomies were realized most frequently 2 years after implementation of VATS segmentectomy (23% vs. 77%; P=0.01).

Conclusions

In comparison with simple segmentectomy, complex segmentectomy by VATS seems to present similar post-operative complication rates. Learning curve and progressive increase in acceptance by surgeons seem to be key elements for successful implementation of complex segmentectomies and could explain the shorter length of stay we observed.

Clinical Application of Near-Infrared Thoracoscopy With Indocyanine Green in Video-Assisted Thoracoscopic Anatomical Segmentectomy

Background. To confirm the impact of near-infrared thoracoscopy with intravenous injection of indocyanine green (ICG) during video-assisted thoracic surgery (VATS)-based segmentectomy. Materials and Methods. We retrospectively screened the perioperative data in total 21 patients who underwent segmentectomy by VATS. The segmental arteries and bronchi were identified with the help of preoperative 3-dimensional computed tomography images. Among them, clinical effectiveness and postoperative complications were analyzed. VATS segmentectomy was performed using a 3-port approach with systemic intravenous injection of ICG. Results. A total of 21 patients underwent VATS-based segmentectomy with ICG injection. The mean operation time was 126.19 ± 15.32 minutes, and the mean bleeding volume was 158.10 ± 39.95 mL. In addition, the average drainage volume 1 day after surgery was 153.81 ± 32.19 mL, and mean duration of drainage was 1.62 ± 0.59 days. Complications occurred in 6 of the 21 patients. Two patients had pneumonia, 3 had arrhythmia, and 1 had prolonged air leak. There were no complications resulting from ICG angiography. Conclusions. Near-infrared thoracoscopy with intravenous injection of ICG is a safe, fast, simple, and highly accurate method that can be used to identify the intersegmental plane and facilitate the quality of VATS-based segmentectomy.

Clarification of the resection line non-intubated segmentectomy using indocyanine green

A reflection on the measure of fluorescence specificity of indocyanine green (ICG) in non-intubated pulmonary segmentectomy.

Recent fluorescence-based optical imaging for video-assisted thoracoscopic surgery segmentectomy

Background

The importance of fluorescence-based optical imaging in various fields of surgery is increasing. This is a prospective cohort study aimed to investigate the feasibility and efficacy of indocyanine-green fluorescence (ICGF)-based navigation for near-infrared (NIR) thoracoscopic segmentectomy.

Methods

ICGF-based video-assisted thoracoscopic surgery (VATS) segmentectomy was performed in 149 patients. Each patient underwent preoperative evaluation by multidetector-row computed tomography (MDCT), which provided three-dimensional simulations of vascular structures, segmental bronchi, and lung tumor. During the procedure, low-dose ICG (0.25 mg/kg) was injected systemically after the target segmental pulmonary arteries and bronchus were divided. Under NIR-thoracoscopic guidance, an ICG fluorescent line was marked by electric scalpel, followed by division of lung parenchyma along the line by electric scalpel or endoscopic staples.

Results

An intersegmental line of ICGF was visible in 98% of patients, even with the use of low-dose ICG. Neither ICG-related adverse events nor procedure-related major complications occurred. The 5-year overall (OS) and recurrence-free survival (RFS) rates were 91.8% and 98%, respectively. Localized recurrence at the resected site did not occur in any patient.

Conclusions

ICGF-based navigation for NIR VATS segmentectomy for patients with lung cancer is feasible and effective.

Clinical outcome and risk factors for complications after pulmonary segmentectomy by video-assisted thoracoscopic surgery: results of an initial experience

Background

Pulmonary anatomical segmentectomies are increasingly being done via video-assisted thoracoscopic surgery (VATS). We analyzed clinical outcomes and risk factors for post-operative complications after pulmonary segmentectomy by VATS was introduced in two institutions.

Methods

We retrospectively reviewed records of all patients who underwent anatomical pulmonary segmentectomy by VATS from 2014 to 2016 at the university hospitals of Geneva and Lausanne in Switzerland.

Results

One hundred twenty-nine patients (64 men; median age 68 years, range, 29-85 years) underwent anatomical VATS segmentectomy for primary lung tumors (n=100), metastases (n=16) and benign lesions (n=13). The overall 30-day mortality and morbidity rates were 0.8% and 31%, respectively. The reoperation rate was 4.7% [indications: hemothorax 2, prolonged air leak (PAL) 2, segmental torsion 1, empyema 1]. Chest drainage lasted for a median of 2 days (range, 1-33 days) and patients were discharged from the hospital after a median of 6 days (range, 2-37 days). Postoperative complications were mainly associated with chronic obstructive pulmonary disease (COPD) [odds ratio (OR) 2.54 and 95% confidence interval (95% CI), 1.18-5.47], and smoking pack-years >50 units (OR 5.27; 95% CI, 1.68-16.55). Nine patients (9%) presented with distant recurrences. Nodule size >2 cm was associated with decreased disease-free survival (DFS) (P=0.04). There was no association between surgical experience in VATS segmentectomy and DFS or postoperative complications.

Conclusions

Segmentectomies can be safely performed by VATS in an initial experience and result in favorable clinical outcome. COPD and smoking pack-years are associated with an increased risk of complications.

Impact of near-infrared angiography on the quality of anatomical resection during video-assisted thoracic surgery segmentectomy

Background

The aim of the present study was to assess the impact of near-infrared angiography in guiding intraoperatively sublobar anatomical resection by video-assisted thoracic surgery (VATS).

Methods

We retrospectively analyzed data from 67 patients who underwent segmentectomy by VATS from November 2014 to November 2017 at the University Hospitals of Geneva, Switzerland. The need to modify arterial or parenchymal resection based on intraoperative near-infrared imaging was considered the primary study outcome.

Results

A total of 67 patients (28 men, 39 women, mean age 66±10 years) underwent anatomical pulmonary segmentectomy by VATS. Histological analysis revealed a primary lung tumor in 59 patients. The mean ± standard deviation (SD) operation time was 154±51 minutes. Identification of the intersegmental plane (ISP) with near-infrared angiography was achieved in 88% of patients and led to modification of the resection during segmentectomy in 7 patients (10%), avoiding inappropriate resection; 2 patients had distant tumor recurrences (3%).

Conclusions

Near-infrared angiography during VATS segmentectomy is effective for identifying ISPs, with respect to the oncological margins, as well as for correcting the anatomical resection.