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

Unlocking the Potential of Computed Tomography-Guided Tracers in Pinpointing Lung Lesions during Surgery: A Collaborative Multi-Institutional Journey

Background: Multiple techniques exist for the preoperative localization of small, deeply located solid or subsolid pulmonary nodules to guide limited thoracoscopic resection. This study aims to conduct a multi-institutional comparison of three different tomography-guided tracers' methods. Methods: A retrospective multicenter cross-sectional study was conducted. All patients suitable for CT-guided tracers with microcoil (GROUP1, n = 58), hook wire (GROUP2, n = 86), or bioabsorbable hydrogel plug (GROUP3, n = 33) were scheduled for video-assisted thoracoscopic wedge resection. Outcome variables: successful nodule localization, safety, and the feasibility of the tracers' placement. A χ2 test or Fisher's test for expected numbers less than five and a Kruskal-Wallis test were used to analyze the categorical and continuous variables, respectively. For the power calculations, we used G*Power version 3.1.9.6. Results: One hundred seventy-seven patients underwent the localization and resection of 177 nodules detected with three different CT-guided tracers. A significant difference was recorded for cancer history (p = 0.030), respiratory function, Charlson comorbidity index (p = 0.018), lesion type (p < 0.0001), distance from pleura surface (p < 0.0001), and time between preoperative CT-guided tracers and surgical procedures (p < 0.0001). Four post-procedural complications were recorded and in GROUP2, four cases of tracer dislocations occurred. Finally, hook wire group was associated with the shortest surgical time (93 min, p = 0.001). Conclusions: All methods were feasible and efficient, resulting in a 100% success rate for the microcoils and the bioabsorbable hydrogel plugs and a 94.2% success rate for the hook wires. Our results highlight the need to choose a technique that is less stressful for the patient and helps the surgeon by extending the approach to deep nodules and resecting over the course of several days from deployment.

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.

A novel technique proposition for determining the resection margins in lung resection by using a thermal camera

OBJECTIVES

Determination of resection margins is very important in anatomical lung resections for both oncologic outcomes and postoperative complications. Absence of intersegmental plans naturally in segmentectomy surgeries and presence of incomplete fissure variationally in pulmonary lobectomy procedures constitute a challenge for surgeons in determining resection margins. Thoracic surgeons can prefer various techniques such as inflation deflation method, indocyanine green imaging, and three-dimensional segment modeling to cope with this problem. These techniques have some disadvantages such as high cost, the necessity of intravenous drug administration, need for an additional imaging system and ineffectiveness due to emphysema, anthracotic lung surface or interalveolar pores. Here we studied an alternative method for the solution of these disadvantages and aimed to demonstrate the correctness of a hypothesis based on detecting the cooling of the ischemic lung portion by a thermal camera after dividing the related pulmonary artery.

METHODS

We planned determining margins of resection with a thermal camera in patients scheduled for pulmonary lobectomy or segmentectomy. We made some measurements and mapping with a thermal camera before and after the dividing of pulmonary artery of related lobe or segment then processed the images taken with a software on the computer.

RESULTS

We detected a significant decrease in temperature in the ischemic lung area and demonstrated mapping the demarcation line between ischemic and perfused areas effectively by thermography in a total of 32 patients underwent lung resection.

CONCLUSION

Pulmonary resection margins can be detected effectively by thermography in patients.

[Delphi Expert Consensus of the German Society for Thoracic Surgery on Segmentectomy for Non-small Cell Lung Cancer]

BACKGROUND

Findings from two recently published randomised controlled trials have shown favourable oncological results of segmentectomy for early-stage NSCLC < 2 cm. This has generated a growing interest in this procedure, which is however considered technically more challenging than lobectomy. The aim of the working group of the German Society for Thoracic Surgery (DGT) was to address, via an expert consensus project, topics concerning implementation of segmentectomy in lung cancer surgery.

METHODS

The assigned group of the DGT designed and conducted two electronic rounds of questions in all major thoracic and lung cancer centres in Germany. The steering group predefined a priori the threshold of consensus of 75% or greater. The results were discussed in an expert meeting, leading to a final Delphi poll for selected topics and questions.

RESULTS

Thirty-eight questions on segmentectomy for NSCLC were proposed in two rounds and voted on. After the final Delphi process, a consensus was reached for the following topics: non-inferiority of segmentectomy vs. lobectomy for tumours < 2 cm, segmentectomy as an alternative if lobectomy is functionally not feasible, use of intraoperative techniques for identification of intersegmental borders. No consensus could be reached for topics such as frozen section for intraoperative ascertainment of radicality, as also for the indication of a re-do lobectomy in case of an occult N1 lymph node status.

CONCLUSION

Our manuscript depicts the results of a Delphi process in 2020/2021 involving experts of the German Society for Thoracic Surgery on the implementation of segmentectomy in lung cancer patients. In general, a very high rate of consensus was documented for the majority of the topics concerning the indication and execution of lung segmentectomy.

Noninvasive 3D-CT simulation versus glue injection to localize small pulmonary nodules prior to anatomical segmentectomy: a randomized controlled trial

OBJECTIVES

This study aimed to investigate whether adding glue injection to three-dimensional computed tomography bronchography and angiography (3D-CTBA) has extra benefits to facilitate anatomical segmentectomy for pulmonary nodules.

METHODS

We conducted a randomized controlled trial. The patients undergoing thoracoscopic segmentectomy assisted with 3D-CTBA simulation were enrolled. Then, they were divided into the 3D-CTBA group and the glue-labelling group who received additional computed tomography-guided percutaneous glue (2-octyl cyanoacrylate) injection to label the nodules. The primary outcome was the resection rate of the nodules, and the secondary measures included the operation time, complications and thorax drainage.

RESULTS

A total of 173 patients were randomized into the 3D-CTBA group (89 patients) and glue-labelling group (84 patients) between January 2018 and March 2019. Before the segmentectomy, the patients using glue labelling recorded 5 (6.0%) cases of pneumothorax, 2 (2.4%) cases of haemothorax and 1 (1.2%) case of severe chest pain. All the surgical procedure was performed fluently and safely. The resection rate of the nodules was 100% in both groups. Furthermore, these patients demonstrated similar operation time [(141.5 ± 41.9) vs (142.1 ± 38.9) min], estimated blood loss [(111.3 ± 74.0) vs (106.0 ± 63.8) ml], duration of chest tube duration [(5.1 ± 3.0) vs (5.0 ± 3.5) days] and total drainage volume [(872.3 ± 643.1) vs (826.7 ± 806.0) ml], with a P-value of >0.05 respectively. In addition, 6 (7.1%) patients in the glue-labelling group and 6 (6.7%) patients in the 3D-CTBA group reported air leakage (>5 days) and chylothorax.

CONCLUSIONS

Noninvasive 3D-CTBA alone is probably sufficient to facilitate anatomical segmentectomy. The additional invasive glue labelling could be avoided in selected patients who undergo intentional segmentectomy.

CLINICAL TRIAL REGISTRATION

The trial was registered under the Chinese Clinical Trial Registry (ChiCTR). Identifier: ChiCTR1800018293, https://www.chictr.org.cn/showproj.html?proj=29345.

Identifying the intersegmental plane for segmentectomy using the open insufflation technique

Accurate identification of the intersegmental plane is the key to successful segmentectomy. This case series included 41 patients who underwent uniportal thoracoscopic segmentectomy using the open insufflation method to identify the intersegmental plane for pulmonary nodules. The median age of the patients was 58 (range 35-73) years, and 63.4% were female. Malignant pulmonary nodules accounted for 80.5% of cases and were staged as 0-IA2. Seventeen patients underwent a single subsegmentectomy or single segmentectomy, and 24 underwent combined subsegmentectomy or subsegmentectomy combined with segmentectomy. There was no conversion to multiportal video-assisted thoracoscopic surgery, open surgery, or lobectomy. The median operative time was 84 (range 45-194) min, and the median blood loss was 50 (range 10-150) ml. The median chest tube duration and postoperative hospital stay were 2 (range 1 - 7) days. One (2.4%) developed an air leak for >5 days. No deaths occurred within 30 days after surgery.

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.

What's new in minimally invasive thoracic surgery? Clinical application of augmented reality and learning opportunities in surgical simulation

Lung cancer represents the most lethal cancer worldwide. Surgery is the treatment of choice for early-stage non-small cell lung cancer, with an overall survival that can reach 90% at 5 years, but its detection is difficult to achieve due to the lack of symptoms. Screening programs are crucial to identify small cancer. Minimally invasive surgery has modified the therapeutical approach of these tumors, becoming the standard of care, with an important clinical yield in terms of reduction of postoperative pain and length of hospital stay. The aim of this mini-review is to explore and describe two important and innovative aspects in the context of "growing opportunities in minimally invasive thoracic surgery": the clinical application of augmented reality and its advantages for patient and surgeon, and the pedagogical issue through simulation-based training.

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.

Identification of the intersegmental plane via electromagnetic navigation for anatomical segmentectomy

Accurate identification of the physiological intersegmental plane is crucial for successful anatomical segmentectomy. Current techniques, such as the inflation-deflation method, may result in uncertain cutting lines, leading to unsuitable resection extents. Here, we demonstrated the successful use of electromagnetic navigation with methylene blue dye-marking to preoperatively and precisely identify the physiological intersegmental plane in two patients with small-sized peripheral non-small cell lung cancer (NSCLC). This novel technique offers the potential for precise cutting lines that align closely with the physiological intersegmental plane, thus improving the accuracy and efficacy of anatomical segmentectomy for these selected NSCLC patients.

Endobronchial indocyanine green instillation to identify the intersegmental plane for successful segmentectomy

The traditional indications for lobectomy for resectable Non-small Cell Lung Cancer (NSCLC) may be set to change. Recently, anatomical segmentectomy (AS) versus lobectomy as an approach for early-stage NSCLC has been described in phase 3 randomised controlled trials. The demand for methods to facilitate AS may increase as a consequence. We describe three cases of AS using the combination of endobronchial infiltration of indocyanine green (ICG) to identify the intersegmental plane (critical for the performance of AS), and Computed Tomography (CT) guided methylene blue injection for lesion localisation. The operations were completed successfully demonstrating satisfactory post-operative outcomes including lesion resection with clear surgical margins and acceptable length of stay. We believe that endobronchial instillation of ICG and CT-guided methylene blue injection for lesion localisation show promise as a technique to complement parenchymal sparing thoracic oncological surgery.

Fissureless technique of robotic left lingular segmentectomy for primary lung cancer with incomplete fissure: a case report

BACKGROUND

Pulmonary segmentectomy for a lung with an incomplete interlobar fissure may complicate persistent air leakage. The fissureless technique is often used in lobectomy to prevent persistent air leakage. We herein describe successful use of the fissureless technique for segmentectomy with the aid of a robotic surgical system.

CASE PRESENTATION

A 63-year-old man was clinically diagnosed with early-stage lung cancer for which lingular segmentectomy was indicated. A preoperative image revealed a lung with an incomplete fissure. Based on three-dimensional reconstruction imaging, we planned to divide the hilum structures in the order of the pulmonary vein, bronchus, and pulmonary artery and finally resect the lung parenchyma by dividing the intersegmental plane and interlobar fissure. This fissureless technique was successfully conducted using a robotic surgical system. The patient did not develop persistent air leakage and was alive without recurrence 1 year after segmentectomy.

CONCLUSIONS

The fissureless technique may be a useful option in segmentectomy for a lung with an incomplete interlobar fissure.

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.

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.

"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.

Division of the intersegmental demarcation using the "modified hand-tearing method" is safe and feasible in thoracoscopic anatomical segmentectomy

BACKGROUND

The accurate and safe division of the intersegmental demarcation (ISD) is critical and challenging during thoracoscopic anatomical segmentectomy. Here, we provide an improved technique which emphasizes the application of an electric hook and blunt division of ISD. The technique is termed as the "modified hand-tearing method" (MHT method) with combined application of an electric hook and staplers. The study aimed to review the outcomes of patients who underwent thoracoscopic anatomical segmentectomy, with or without the MHT method in our institute and assess its feasibility and safety. In addition, we compared the feasibility between video-assisted thoracoscopic surgery (VATS) and robot-assisted thoracoscopic surgery (RATS) using the MHT method.

METHODS

From 2018 July to 2021 June, we retrospectively analyzed 701 patients who underwent segmentectomy. Using propensity score matching, data of two well-matched pairs of 276 cases in the MHT method and non-MHT method groups, and two well-matched pairs of 40 cases in the VATS and RATS subgroups were obtained. The clinical and perioperative characteristics of patients were compared between groups.

RESULTS

Compared with the non-MHT method group, the MHT method group had shorter operation time and shorter postoperative hospital stay. Period of chest tube drainage and postoperative total drainage and postoperative complications had no between-group difference. Compared with VATS, the RATS subgroup had less intraoperative bleeding and shorter postoperative hospital stay.

CONCLUSION

Division of ISD using the MHT method has advantages in precision and ease of operation, so it has the potential to become a feasible and effective method for thoracoscopic anatomical segmentectomy.

Research on the application of uniportal video-assisted thoracoscopic segmental resection of the lung in elderly patients with non-small cell lung cancer aged over 65 years

Introduction

The literature regarding the application of uniportal video-assisted thoracoscopic segmental resection of the lung in patients aged over 65 years with non-small cell lung cancer (NSCLC) is sparse. This paper reports 175 cases of uniportal video-assisted thoracoscopic segmental resection of the lung performed at one center, of which 63 patients were over 65 years old.

Aim

To investigate the safety and feasibility of uniportal video-assisted thoracoscopic segmental resection of the lung in elderly patients aged over 65 years with NSCLC.

Material and methods

A retrospective analysis of 175 NSCLC patients who underwent uniport video-assisted thoracoscopic segmental resection of the lung in the center from August 2018 to August 2020 was conducted, and based on the age of 65 years, patients were divided into elderly and non-elderly groups. The general data and perioperative indicators of the two groups were compared.

Results

The procedures were completed in all patients without death or conversion to open surgery. In the general data of the two groups of patients, the prevalence of emphysema in the elderly group was significantly higher than that in the non-elderly group (p = 0.001). However, there was no statistically significant difference between the two groups in surgery time, intraoperative blood loss, thoracic drainage tube retention time, postoperative hospital stay, incision satisfaction, or postoperative complications (p > 0.05).

Conclusions

Uniportal video-assisted thoracoscopic segmental resection of the lung is feasible and safe in elderly patients with NSCLC aged over 65 years.

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.

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.

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.

Hybrid technique of virtual-assisted lung mapping and systemic indocyanine green injection for extended segmentectomy

BACKGROUND

Various approaches have been used to assist and facilitate segmentectomy with favorable oncological outcomes. We describe a hybrid approach comprising virtual-assisted lung mapping (VAL-MAP), which is a preoperative bronchoscopic dye-marking technique, combined with systemic indocyanine green (ICG) injection.

CLINICAL PRESENTATION

An asymptomatic 64-year-old man was referred to our department because of a lung nodule detected during his annual medical checkup. The chest computed-tomography image revealed a 16-mm, partly solid, ground-glass nodule in the left segment 4. Because the nodule was hardly palpable and deeply located between the left upper division segment and the left lingular segment, we performed VAL-MAP to facilitate extended left lingulectomy. Five dye markings were undertaken preoperatively. Surgery to remove the nodule was then conducted via complete three-port video-assisted thoracic surgery. The VAL-MAP markings were easily identified intraoperatively and helped locate the nodule. The intersegmental plane was identified by the ICG injection. The resection line was determined based on the intersegmental plane identified by the ICG injection and the site of the nodule suggested by the VAL-MAP markings. Following the resection line, we thoracoscopically achieved extended lingulectomy with sufficient surgical margins. The patient was discharged with no complications. The pathological diagnosis was adenocarcinoma in situ.

CONCLUSION

The hybrid technique of VAL-MAP and systemic ICG injection can be useful for accomplishing successful extended segmentectomy.

Left apicoposterior segmentectomy for lung cancer with displaced segmental bronchus: a case report

Background

Pulmonary segmentectomy can be challenging when thoracic surgeons encounter anatomical anomalies. A displaced left apicoposterior bronchus is a rare bronchial anomaly that makes lung anatomical resection challenging. We herein present a case of successful left apicoposterior segmentectomy for lung cancer in a patient with an anomalous segmental bronchus.

Case presentation

A 70-year-old man was clinically diagnosed with early-stage lung cancer for which segmentectomy was indicated. A preoperative image revealed a displaced left apicoposterior bronchus that branched behind the left main pulmonary artery. With the aid of three-dimensional reconstruction imaging and systemic indocyanine green injection, we successfully performed left apicoposterior segmentectomy under complete video-assisted thoracic surgery. The pathological diagnosis was adenocarcinoma. The patient was alive without recurrence 8 months after segmentectomy.

Conclusion

Preoperative three-dimensional imaging and systemic indocyanine green injection enabled us to successfully conduct challenging segmentectomy in a patient with an anomalous bronchus.

Right upper lobe segmentectomy guided by simplified anatomic models

Background

To standardize the technical strategy for right upper lobe (RUL) segmentectomy, we previously developed simplified 3-dimensional (3D) anatomic models that classify the RUL anatomy into 14 patterns according to the branching pattern of bronchi and veins. We aimed to study the surgical outcome of RUL segmentectomy guided by these simplified anatomic models.

Methods

Patients were classified into the anatomic models, and the approach to the intersegmental veins was selected accordingly. The intersegmental vein and corresponding intersegmental plane were as follows: V¹b (the apicoanterior plane), V²a (the apicoposterior plane), and V²c (the posteroanterior plane). Clinicopathologic characteristics and short- and long-term outcomes were analyzed retrospectively.

Results

Thirty-four consecutive patients who underwent thoracoscopic RUL segmentectomy guided by simplified anatomic models between January 2016 and December 2019 at Gunma University were analyzed. All the patients were classified into a model: anterior + central Iab type (47%), anterior + central Ib type (41%), anterior II type (12%), or central III type (0%). The standard approaches to intersegmental veins were an anterior approach for V¹b, a posterobronchial approach for V²a, and an interlobar approach for V²c. The approach to intersegmental or intrasegmental veins was modified according to the anatomic model in 4 cases (12%). The median operative time, blood loss, and hospital stay were 222 minutes, 19 grams, and 7 days, respectively. Prolonged air leakage was observed in 1 patient.

Conclusions

Segmentectomy guided by simplified anatomic models promotes anatomic classification, development of a standardized approach for segmental vein identification, and acceptable outcomes, which can facilitate the implementation of RUL segmentectomy.

"Selective bronchus-blowing" method for effective inflate-deflate line identification in lung segmentectomy

Background

We examined two methods for the intraoperative selective bronchial delivery of air, and compared their effectiveness.

Methods

We recruited patients undergoing lung resection with the selective bronchus-blowing method in pulmonary segmentectomy for lung tumors. We assessed two types of bronchial ventilation methods: high-frequency jet ventilation (HFJV) and the bronchus-blowing method, which deliver air to target bronchi using HFJV or a 20G cannula inserted directly into the bronchi, respectively. The inflate-deflate line was classified as clear, slightly clear, and unclear. We examined the relationships between clinicopathological findings and the inflate-deflate line classification, as well as group differences in surgical-related factors.

Results

Among the 86 patients enrolled, 45 received HFJV ventilation and 41 received the bronchus-blowing method of ventilation. There was a significantly higher incidence of complex-type segmentectomies among patients in the bronchus-blowing group than in the HFJV group. The inflate-deflate line was classified as clear, slightly clear, and unclear in 16/7/11 and 25/3/3 patients in the HFJV and bronchus-blowing groups, respectively, according to the inflate-deflate criteria. The inflate-deflate line was identifiable in more cases in the bronchus-blowing group than in HFJV group (P=0.02). Complete resection was significantly less frequent in the HFJV group (73.5%) than in the bronchus-blowing group (90.3%). The rate of unsuccessful surgery was significantly higher among patients with severe emphysema, interstitial pneumonia, and anthracosis.

Conclusions

Intraoperative selective bronchial air supply was attempted for the safe identification of target lung segments. The bronchus-blowing method easily enabled effective visualization of the segmental area within the operative field.

The arterial-ligation-alone method for identifying the intersegmental plane during thoracoscopic anatomic segmentectomy

Background

Currently, methods for identifying the intersegmental plane during anatomical segmentectomy can be classified into 2 categories: the bronchial method and the vascular method. One of the vascular methods, the arterial-ligation-alone method, has not yet been validated or objectively evaluated in a large case series. We thus aimed to confirm that the arterial-ligation-alone method could effectively and accurately identify the intersegmental plane.

Methods

We retrospectively reviewed the records of 104 patients who were scheduled for thoracoscopic anatomic segmentectomy. Preoperative three-dimensional (3D) reconstruction was performed on all the affected lungs to distinguish the targeted segmental arteries, veins and bronchi. The procedure was as follows: first, based on the 3D reconstruction of the lung, the targeted segmental arteries were distinguished and ligated. Second, bilateral pulmonary ventilation was performed with pure oxygen. When the affected lung had completely inflated, contralateral pulmonary ventilation was performed. After waiting for some time, the first intersegmental plane could be obtained, and the time was recorded as T1, with an electric coagulation hook being used for marking. Thirdly, when the targeted segmental veins and bronchi had been ligated, the second intersegmental plane could be obtained by the inflation-deflation method as before, with the waiting time being recorded as T2. The differences between the 2 intersegmental planes were evaluated by 2 experienced chief thoracic surgeons.

Result

In a total of 99 (95.2%) patients, the intersegmental planes were successfully and accurately identified by the arterial-ligation-alone method. Ultimately, 85 (81.7%) patients underwent thoracoscopic anatomic segmentectomy. The results for evaluating the differences between the 2 planes were as follows: completely consistent (94 cases, 94.9%), basically consistent (5 cases, 5.1%), and discrepant (0 cases, 0%). The mean T1 was 13.6±2.7 minutes (range, 8–25 minutes), and the mean T2 was 13.0±2.6 minutes (range, 8–23 minutes), with P=0.100 (95% CI). For 99 patients, the mean nodule size was 1.1±0.34 cm. In the 85 patients who underwent segmentectomy, the mean margin width was 2.84±0.51 cm, the mean operative duration was 165.6±18.3 minutes, the mean operative hemorrhage was 52.1±20.2 mL, and the mean duration of chest tube drainage was 3.9±1.3 days. Postoperative complications related to operative procedures occurred in 2 cases.

Conclusions

The arterial-ligation-only method can effectively, accurately and inexpensively identify the intersegmental plane, and is especially suitable for the patients whose veins or bronchi are difficult to anatomize. Whether the target bronchus is ligated has no effect on the intersegmental plane.

Simple method for distinguishing the intersegmental plane in thoracoscopic lung segmentectomy

Here, we introduce a simple method for delineating the intersegmental border in thoracoscopic pulmonary segmentectomy which can be widely reproduced because it is less time‐consuming, fault‐tolerant, and does not require any special chemical reagents or equipment. This method provides clear and accurate demarcation lines between the inflated and deflated lung parenchyma.

Key points

A method with an effective and simple application which can be popularized. This modified targeted bronchus inflation method provides a clear and accurate intersegmental plane.