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

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

Simply designed robotic combined subsegmentectomy for a lesion in the left S10 via a posterior approach.

Segmentectomies involving the posterior basal segment (S10) of the lower lobe present a challenging surgical procedure due to anatomical complexities, especially when lesions extend towards the lateral basal segment (S9). We introduce a combined subsegmentectomy technique via a posterior approach for a lesion situated between S9b and S10b, which preserves subsegmental branches that do not affect the resection margin of the tumour and facilitates intersegmental division without extending dissection into the interlobar region. This technique, the goal of which is to reduce the extent of dissection and complex stapling, is expected to minimize pulmonary complications and intrathoracic adhesions without compromising oncological outcomes. By potentially mitigating challenges in an ipsilateral reoperation, this approach offers a valuable alternative for managing second lung cancers.

Comparison of ICG-Guided Near-Infrared Fluorescence Imaging and Modified Inflation-Deflation Method in Identifying the Intersegmental Plane During Lung Segmentectomy of Infants.

BACKGROUND: The identification of the intersegmental plane (ISP) is a crucial step in segmentectomy for children with congenital pulmonary airway malformation (CPAM) due to complex anatomical variations. However, there is very limited literature available on this aspect specifically for infant. In this study, we compared the intravenous indocyanine green (ICG)-guided near-infrared fluorescence (NIRF) imaging method with the modified inflation-deflation method in terms of their perioperative characteristics and summarized our experience. METHODS: From June 2021 to November 2022, the data of 83 patients with CPAM who underwent segmentectomy by video-assisted thoracoscopic surgery were retrospectively reviewed. Twenty-eight patients underwent ICG-guided NIRF method, and 56 patients underwent the modified inflation-deflation method, characteristics and clinical outcomes were compared. RESULTS: The median age of the patients was 4.99 months (4.99 ± 1.51) with a mean body weight of 7.54 kg (7.54 ± 1.99). Both methods could accurately identify the ISP. The time taken to clearly display the ISP was shorter in ICG group than in the modified inflation-deflation group (0.18 ± 0.08 vs. 6.49 ± 1.67 min; P < 0.001), and the surgical duration (61.32 ± 14.28 vs. 88.18 ± 8.03 min; P < 0.001) were significantly shorter in the ICG group too. The two groups exhibited differences in the length of chest tube drainage (1.75 ± 1.24 vs. 2.36 ± 1.54 days; P = 0.072) and the length of hospital stay (4.61 ± 1.75 vs. 5.20 ± 3.07 days; P = 0.078), however, the differences were not statistically significant. There were no significant differences between the two groups in the blood lost and postoperative complications. At a follow-up of more than 1 year after operation, all patients had recovered well without recurrence. CONCLUSIONS: According to our experience, the ICG-guided NIRF method was safe and feasible for infants during thoracoscopic segmentectomy, it can quickly display the ISP and shorten the surgical duration compared with the modified inflation-deflation method.

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.

Prevalence and clinical significance of the Sg6/Sg7 intersegmental veins based on re-evaluation of the Couinaud classification for the right posterior portal vein.

Although Segment 6(Sg6) and Segment 7(Sg7) are two independent units, there are currently no clear anatomical boundary markers between Sg6 and Sg7. This study aimed to identify intersegmental veins (ISV) in the intersegmental plane of Sg6 and Sg7, and evaluate the prevalence of ISV, and its clinical significance in anatomical hepatectomy. We analyzed data from 180 patients undergoing abdominal computed tomography (CT) examination, and simultaneously performed 3D reconstruction models of the liver for each patient. The right posterior portal vein was analyzed and re-typed. Furthermore, the existence of ISV was defined, and prevalence and confluence patterns of ISV were analyzed. The author attempted to apply ISV to laparoscopic S6/S7 segmentectomy. We sorted data from the right posterior portal vein and divided it into six types. The ISV could be identified in 82.2% (148/180) of the patients, which were derived from the right hepatic vein (RHV) (91.9%) and right posterior inferior vein (IRHV) (8.1%). Ten ISV-guided laparoscopic Sg6/Sg7 segmentectomy were successfully carried out, seven patients underwent Sg6 segmentectomy, and three patients underwent Sg7 segmentectomy. There was no perioperative mortality. The median operative time was 223 min (range 181-260 min). The median blood loss was 200 ml (range 150-310 ml). The R0 resection rate was 100%. The ISV may be a candidate vessel to distinguish the boundary of the right posterior sector; it is expected to be a landmark in the liver parenchyma of anatomical hepatectomy.

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.

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.

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.

Risk factors for late-onset pulmonary fistula after pulmonary segmentectomy.

Background: Late-onset pulmonary fistula (LOPF) is a well-described complication after segmentectomy, but the precise incidence and risk factors are still unclear. We aimed to determine the incidence of, and risk factors for, LOPF development after segmentectomy. Methods: A single-institution retrospective study was performed. A total of 396 patients who underwent segmentectomy were enrolled. Perioperative data were analyzed to identify the risk factors for LOPF requiring readmission according to univariate and multivariate analyses. Results: The overall morbidity rate was 19.4%. The incidence rates of prolonged air leak (PAL) in the early phase and LOPF in the late phase were 6.3% (25/396) and 4.5% (18/396), respectively. The most common surgical procedures with LOPF development were segmentectomy of the upper-division (n=6) and S6 (n=5). With a univariate analysis, presence of smoking-related diseases did not affect LOPF development (P=0.139). Conversely, segmentectomy with cranial side free space (CSFS) in the intersegmental plane and use of electrocautery to divide the intersegmental plane were associated with a high risk of LOPF development (P=0.006 and 0.009, respectively). A multivariate logistic regression analysis showed that segmentectomy with CSFS in the intersegmental plane and use of electrocautery were independent risk factors for LOPF development. Approximately 80% of patients who developed LOPF recovered by prompt drainage and pleurodesis without reoperation, whereas the remaining patients developed empyema due to delayed drainage. Conclusions: Segmentectomy with CSFS is an independent risk factor for LOPF development. Careful postoperative follow up and rapid treatment are necessary to avoid empyema.

A feasible technique for distinguishing the intersegmental plane by transbronchial injection of iron sucrose.

Objectives: Pulmonary segmentectomy should be the standard surgical procedure for patients in certain clinical scenarios. However, detecting the intersegmental planes both on the pleural surface and within the lung parenchyma remains a challenge. We developed an intraoperative novel method for distinguishing intersegmental planes of the lung via transbronchial injection of iron sucrose (ClinicalTrials.gov number, NCT03516500). Methods: We first performed a bronchial injection of iron sucrose to identify the intersegmental plane of the porcine lung. Then, we conducted a prospective study to evaluate the safety and feasibility of the technique in 20 patients who underwent anatomic segmentectomy. Iron sucrose was injected into the bronchus of target pulmonary segments, and the intersegmental planes were divided with electrocautery or stapler. Results: The median injection of iron sucrose was 90 mL (range, 70-120 mL), and the median time from injection of iron sucrose to demarcation of intersegmental plane was 8 minutes (range, 3-25 minutes). Qualified identification of the intersegmental plane was observed in 17 cases (85%). The intersegmental plane could not be recognized in 3 cases. All patients experienced no complications related to iron sucrose injection or complications of Clavien-Dindo grade 3 or more. Conclusions: Transbronchial injection of iron sucrose is a simple, safe, and feasible approach to identify the intersegmental plane (NCT03516500).

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 (Pvent) and deflated pulmonary lobes (PnV) as well as in deflated pulmonary lobes with divided circulation (PnVC) before dissection of the lobar bronchus. RESULTS: A total of 341 measuring points were evaluated during pulmonary lobectomies. Pulmonary lobes showed a reduced StO2 (Pvent: 84.56% ± 3.92 vs. PnV: 63.62% ± 11.62 vs. PnVC: 39.20% ± 23.57; p<0.05) and NIR-perfusion (Pvent: 50.55 ± 5.62 vs. PnV: 47.55 ± 3.38 vs. PnVC: 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.

[Application of Three-dimensional Computed Tomography Bronchography and 
Angiography Combined with Perfusion Area Identification Technique 
in Uniport Thoracoscopic Complex Segmentectomy].

BACKGROUND: With the extensive application of segmental lung resection in the treatment of early-stage lung cancer, how to complete segmentectomy more accurately and minimally invasively has become a research hotspot. The aim of this study is to explore the application of three-dimensional computed tomography bronchography and angiography (3D-CTBA) combined with perfusion area recognition technique in single-hole thoracoscopic complex segmentectomy. METHODS: From January 2021 to January 2022, the clinical data of 112 consecutive patients undergoing single-port thoracoscopic complex segmentectomy in the Department of Thoracic Surgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. The three-dimensional reconstruction combined with perfusion area identification technique was used to perform the operation and the clinical data were analyzed. RESULTS: The average operation time was (141.1±35.4) min; the initial time of intersegmental plane display was (12.5±1.7) s; the maintenance time of intersegmental plane was (114.3±10.9) s; the intersegmental plane was clearly displayed (100%); the amount of bleeding was [10 (10, 20)] mL; the total postoperative drainage volume was (380.5±139.7) mL; the postoperative extubation time was (3.9±1.2) d; and the postoperative hospitalization time was (5.2±1.6) d. Postoperative complications occurred in 8 cases. CONCLUSIONS: The advantages of 3D-CTBA combined with perfusion area recognition technique are fast, accurate and safe in identifying intersegmental boundary in single-port thoracoscopic complex segmentectomy, which could provide guidances for accuratding resection of tumors, shortening operation time and reducing surgical complications.

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.

Application of Three-dimensional Computed Tomography Bronchography and Angiography Combined with Perfusion Area Identification Technique in Uniport Thoracoscopic Complex Segmentectomy / 中国肺癌杂志

BACKGROUND@#With the extensive application of segmental lung resection in the treatment of early-stage lung cancer, how to complete segmentectomy more accurately and minimally invasively has become a research hotspot. The aim of this study is to explore the application of three-dimensional computed tomography bronchography and angiography (3D-CTBA) combined with perfusion area recognition technique in single-hole thoracoscopic complex segmentectomy.@*METHODS@#From January 2021 to January 2022, the clinical data of 112 consecutive patients undergoing single-port thoracoscopic complex segmentectomy in the Department of Thoracic Surgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. The three-dimensional reconstruction combined with perfusion area identification technique was used to perform the operation and the clinical data were analyzed.@*RESULTS@#The average operation time was (141.1±35.4) min; the initial time of intersegmental plane display was (12.5±1.7) s; the maintenance time of intersegmental plane was (114.3±10.9) s; the intersegmental plane was clearly displayed (100%); the amount of bleeding was [10 (10, 20)] mL; the total postoperative drainage volume was (380.5±139.7) mL; the postoperative extubation time was (3.9±1.2) d; and the postoperative hospitalization time was (5.2±1.6) d. Postoperative complications occurred in 8 cases.@*CONCLUSIONS@#The advantages of 3D-CTBA combined with perfusion area recognition technique are fast, accurate and safe in identifying intersegmental boundary in single-port thoracoscopic complex segmentectomy, which could provide guidances for accuratding resection of tumors, shortening operation time and reducing surgical complications.

Application of pulmonary circulation single-blocking method in intersegmental plane identification during segmentectomy / 中国胸心血管外科临床杂志

@#Objective    To introduce a new method for identifying intersegmental planes during thoracoscopic segmentectomy using pulmonary circulation single-blocking in the target segment. Methods    To retrospectively analyze the clinical data of 83 patients who underwent thoracoscopic pulmonary segmentectomy from January 2019 to March 2020 using the pulmonary circulation single-blocking method. There were 33 males and 50 females, with a median age of 54 (46-65) years, and they were divided into a single vein group (SVG, n=31) and a single artery group (SAG, n=52), and the clinical data of two groups were compared. Results    The intersegmental planes were identified successfully in both groups and there were no statistically significant differences between the two groups in terms of intersegmental plane management (P=0.823), operating time (P=0.786), intraoperative blood loss (P=0.775), chest drainage time (P=0.659), postoperative hospital stay (P=0.824) or the incidence of postoperative complications (P=1.000). Conclusion    The use of pulmonary circulation single-blocking for intersegmental plane identification during thoracoscopic segmentectomy is safe and feasible, and the intersegmental plane can be satisfactorily identified by the single-blocking of arteries or veins.

Comparison of bronchial methylene blue staining and modified inflation-deflation method in identifying the intersegmental plane during lung segmentectomy.

Background: Identification of the intersegmental plane (ISP) is the critical step in lung segmentectomy because of the complicated anatomic variations. Bronchial methylene blue staining was developed by our team in 2015 and is now commonly used at our center, it could rapidly and accurately identify the ISP. In this study, we aimed to compare bronchial methylene blue staining with the modified inflation-deflation method in terms of their perioperative characteristics and to present our experience of the methylene blue method. Methods: From June 2020 to September 2021, the data of 112 patients with pulmonary ground-glass nodules who underwent segmentectomy by video-assisted thoracoscopic surgery were retrospectively reviewed. Sixty-two patients underwent bronchial methylene blue staining, and 50 patients underwent the modified inflation-deflation method. Results: Both methods could accurately identify the ISP. The time taken to clearly display the ISP (82.94±28.08 vs. 868.20±145.89 seconds; P<0.001) and the surgical duration (131.69±32.05 vs. 146.08±28.11 minutes; P=0.014) were significantly shorter in the bronchial methylene blue staining group than in the modified inflation-deflation group. There were no significant differences between the two groups in the bleeding volume, drainage time, and length of postoperative hospital stay, as well as in most other perioperative characteristics. Conclusions: Compared with the modified inflation-deflation method, the bronchial methylene blue staining method can quickly display the ISP and shorten the surgical duration. This method is safe and feasible, can be widely applied during thoracoscopic anatomic segmentectomy.

Staplers versus energy devices for the intersegmental plane separation in thoracoscopic segmentectomy: a comparative study.

BACKGROUND: In segmentectomy, in addition to the anatomy of the segmental hilum, the identification and separation of the intersegmental plane is also an important step of the operation. Because of its simplicity and high efficiency, most thoracic surgeons choose the staplers. But the energy devices also have its unique advantages in the separation of the intersegmental plane. This study compared the clinical efficacy of staplers and energy devices in the separation of the intersegmental planes during the uniport thoracoscopic segmentectomy through the clinical data. METHODS: Clinical data of 89 patients undergoing uniport VATS lung segmentectomy from January 2019 to October 2020 at the First Affiliated Hospital of Soochow University were analyzed retrospectively. According to the different treatment methods of intersegmental plane, the patients were divided into two groups, 55 in the stapler group and 34 in the energy device group. The clinical data of the two groups were compared and analyzed statistically. And the univariate and multivariate logistic regression were also used to explore the influencing factors of postoperative complications. RESULTS: Lung segmentectomy was successfully operated in both groups. There were statistically significant differences in operative duration, number of staplers used, surgical expenses and postoperative complications (P < 0.05). In terms of general data, including tumor location, operative hemorrhage, drainage volume on the first postoperative day, total postoperative drainage volume, postoperative chest tube retention duration, postoperative hospital stay, postoperative blood routine indexes, and postoperative pulmonary function indexes after 3 months, no significant differences were observed (P > 0.05). Smoking history (OR 5.08, 95% CI 1.05-24.56, P = 0.043) and intersegmental plane treatment (OR 3.18, 95% CI 1.11-9.14, P = 0.031) were risk factors for postoperative complications. Patients of the energy device group had a higher incidence of postoperative complications. CONCLUSIONS: In uniport thoracoscopic segmentectomy, the use of energy devices to treat the intersegmental plane will result in longer operative duration and higher postoperative complication rate, but it does not affect postoperative recovery and can help reduce surgical expenses. Both methods are safe and reliable. Clinically, the two methods can be reasonably selected according to the specific situation.

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

BACKGROUND: Thoracoscopic segmentectomy is a common surgical procedure in thoracic surgery today. However, identifying the intersegmental plane is difficult in the surgical process. Therefore, we evaluated the feasibility of the arterial ligation method for determining the intersegmental plane and compared the demarcation status with the intravenous indocyanine green (ICG). METHODS: We retrospectively reviewed the records of 35 patients with peripheral small lung nodules who underwent thoracoscopic segmentectomy between May and December 2020. First, the preoperative three-dimensional reconstruction was performed to distinguish the location of lung nodules and the anatomical structures of targeted segmental arteries, veins, and bronchi. Second, the targeted segmental arteries were ligated, and the intersegmental plane was determined by the inflation-deflation technique. The waiting time for the appearance of the inflation-deflation line was recorded. Thirdly, the intersegmental plane was identified again using the ICG fluorescence method. Finally, the consistency of the two intersegmental planes was evaluated. RESULTS: The intersegmental planes were successfully observed in all patients using the arterial ligation method. Thirty-four patients underwent segmentectomy as planned, and one patient finally underwent lobectomy due to insufficient surgical margin. The waiting time for the appearance of the intersegmental plane by arterial ligation method was 13.7 ± 3.2 min (6-19 min). The intersegmental planes determined by the arterial ligation method and the ICG fluorescence method were comparable, with a maximum distance of no more than 5 mm between the two planes. The mean operative duration was 119.1 ± 34.9 min, and the mean blood loss was 76.9 ± 70.3 ml. No evident air leakage was found during the operation. Only one patient experienced a prolonged air leak (≥ 5 days) during the postoperative recovery. No atelectasis occurred in all cases. The chest tube duration was 3.1 ± 0.9 days. CONCLUSION: The arterial ligation method can efficiently and accurately identify the intersegmental plane, comparable to the ICG fluorescence method.

Segmental volumetric analysis with a ventilated or perfused area: identifying the intersegmental plane.

OBJECTIVES: Two methods are available to identify the intersegmental plane during segmentectomy: the inflation-deflation method, based on the ventilation area, and injection of indocyanine green, based on the pulmonary arterial distribution. However, whether the intersegmental plane created by these 2 methods matches remains unknown. Our goal was to identify the demarcation lines based on bronchial and arterial territories using 3-dimensional computed tomography-based volumetry. METHODS: We collected data from patients who underwent thoracoscopic segmentectomy in our hospital between April 2012 and May 2021. Three-dimensional images were reconstructed from the preoperative contrast-enhanced computed tomography data using the SYNAPSE VINCENT software program. The volume of the affected area and the distance of the tumour from the intersegmental plane were calculated based on each affected artery and bronchus. Each calculated volume was compared to each affected segment using a paired t-test. RESULTS: Of 195 patients, 114 underwent upper lobe segmentectomy, and 81 underwent lower lobe segmentectomy. In upper lobe segmentectomy, the affected arterial segmental volume was smaller than the bronchial volume (505.0 ml vs 539.4 ml, P < 0.001). In lower lobe segmentectomy, there was no significant difference between arterial and bronchial volumes (234.6 ml vs 236.9 ml, P = 0.607). The volume of the affected arterial segmental lung and the distance of the tumour from the intersegmental plane were significantly smaller than the bronchial volume in upper lobe segmentectomies. CONCLUSIONS: As per the results, the affected segmental volume delineated by the indocyanine green method would be underestimated in upper lobe segmentectomy.