Novel development of Spectra-A using indocyanine green for segmental boundary visibility in thoracoscopic segmentectomy

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.

How preserved regional pulmonary function after thoracoscopic segmentectomy in clinical stage I non-small cell lung cancers in right upper lobe

OBJECTIVE

To investigate the efficacy of regional respiratory preservation after pulmonary resection for clinical stage I non-small cell lung cancer (NSCLC) in right upper lobe.

METHODS

This retrospective study analysed patients with clinical stage I NSCLC who underwent open thoracotomy lobectomy (OTL, n = 45), thoracoscopic lobectomy (TSL, n = 137), and thoracoscopic segmentectomy (TSS, n = 37) in right upper lobe. The forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were examined at 3 and 6-12 months after the operation. The pre- and post-operative lung volumes were evaluated by three-dimensional reconstructed computed tomography. The rates of post- and pre-operative FVC, FEV1, and lung volumes were compared amongst the three groups.

RESULTS

Significant differences were found in both FVC and FEV1 at 6-12 months between TSL and OTL (p < 0.01 and p = 0.02, respectively). The respiratory recovery rates of FVC and FEV1 at 6-12 months were significantly higher in TSS (98.6% ± 1.52% and 96.5% ± 1.66%) than in TSL (93.4% ± 0.79% and 90.4% ± 0.86%) (FVC: p < 0.01 and FEV1: p < 0.01). The volumetric changes were greater in TSL than in TSS for the right middle lobe (19.6% ± 2.39% and 9.59% ± 4.66%; p = 0.06) and right lower lobe (48.3% ± 2.84% and 27.9% ± 5.47%; p < 0.01) CONCLUSION: TSS might be superior to TSL or OTL depending on the moderate expansion of the remaining right lobes.

Efficacy of Xenon Light With Indocyanine Green for Intersegmental Visibility in Thoracoscopic Segmentectomy

BACKGROUND

We previously reported useful methods that can be implemented to identify intersegmental boundary lines (IBLs) by using an intravenous indocyanine green (ICG) fluorescence imaging system (ICG-FS) during a thoracoscopic anatomical segmentectomy (TAS). The aim of this study was to evaluate the recently released third-generation ICG-FS that features an emphasizing xenon-light source for IBL identification.

METHODS

We prospectively studied cases involving 106 consecutive patients who underwent TAS. Intraoperatively, we used the third-generation ICG-FS, the conventional ICG methods (CIM) emphasizing xenon-light (CIM-X), and the spectra-A method (SAM) emphasizing xenon-light (SAM-X), for IBL identification. Furthermore, 16 of the 106 patients (15%) could be simultaneously evaluated using old-generation ICG-FSs, CIM, and SAM. All images were completely quantified for illuminance and for three colors, red, green, and blue.

RESULTS

IBLs were successfully identified in all the patients (100%) with no adverse events. The SAM-X significantly increased the illuminance, especially in the resecting segments, compared to the CIM (39.0 versus 22.2, P < 0.01) and SAM (39.0 versus 29.3, P < 0.01), with enhanced red color compared to the CIM (33.1 versus 21.9, P < 0.01) and SAM (33.1 versus 14.0, P < 0.01). Furthermore, the SAM-X significantly increased the illuminance contrast compared to the CIM-X (34.1 versus 15.3, P < 0.01).

CONCLUSIONS

The present study suggests that the SAM-X potentially provided images with the highest visibility and colorfulness compared to the older generation ICG-FSs or CIM-X. Secure IBL identification can be more easily and safely performed using the SAM-X.

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.

[Advances in Identification of Intersegmental Plane during Pulmonary Segmentectomy]

With the popularity of computed tomography (CT) scan in recent years, early stage lung cancer has been discovered in large numbers of patients and pulmonary segmentectomy has been widely used clinically. Identification of the intersegmental plane is one of the key steps in pulmonary segmentectomy, and current methods for identifying the intersegmental plane are numerous and have their own advantages and disadvantages. We will review relevant methods to help the clinical practice.
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Favorable clinical application for segmental bronchial closure based on experiment results

Background

We previously reported the clinical application of powered vascular staple (PVS) for closure of subsegmental or segmental bronchus (SSB). This study aimed to measure breakdown pressure in experiment and to investigate bronchopleural fistula (BPF) after thoracoscopic segmentectomy (TS).

Methods

Part 1: a total of 30 cadaveric pigs were used, and bronchi were categorized into the following four groups: small [S, bronchial outer diameter (BOD) of 4-8 mm, n=8], medium (M, 9-10 mm, n=9), and large (L, >10 mm, n=13). We additionally added a single additional suture to compensate for weak sites with large BOD (group R, n=6). The pressure was slowly increased, and stump breakdown was observed. Part 2: we investigated the morbidity of BPF formation at follow-up of at least 6 months in a total of 217 patients.

Results

Part 1: the mean leak pressure was the highest in M, followed by groups S, R and L'. However, the significant difference was not found between S and R. Part 2: no BPF was observed, clinically.

Conclusions

Based on experimental results and clinical experience, the proper selection of PVS should contribute to the safety, feasibility, and success as SSB closure.

Thoracoscopic lobectomy using indocyanine green fluorescence to detect the interlobar fissure in a patient with displaced B3 and absence of fissure: A case report

A 90‐year‐old woman was admitted to our hospital with suspected lung adenocarcinoma. Preoperative three‐dimensional reconstructed computed tomography revealed displacement of the anterior segmental bronchus (B3) arising from the right middle lobe bronchus with absence of the fissure between the right upper and middle lobes. A complete thoracoscopic right upper lobectomy was successfully performed. It is crucial to identify such anomalies prior to lung resection to avoid intraoperative complications during thoracoscopic lobectomy or segmentectomy. Additionally, intravenous indocyanine green with a fluorescence system was useful to identify the proper interlobar fissure boundary intraoperatively. To the best of our knowledge, this is the first reported case of thoracoscopic lobectomy for lung cancer with displaced B3 and absence of the interlobar fissure to be performed by applying the intravenous indocyanine green method.