Thoracoscopic anatomical lung segmentectomy using 3D computed tomography simulation without tumour markings for non-palpable and non-visualized small lung nodules

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.

Multiscale reconstruction of bronchus and cancer cells in human lung adenocarcinoma

BACKGROUND

While previous studies primarily focused on the structure of the normal whole mouse lung, the whole bronchus and cytoarchitectural details of the mouse intact lung lobe have been discovered at single-cell resolution. Revealing the sophisticated lung adenocarcinoma structure at three-dimensional (3D) and single-cell level remains a fundamental and critical challenge for the pathological mechanism research of lung adenocarcinoma (LA).

METHODS

Fluorescence micro-optical Sectioning Tomography (fMOST) combined with PI staining were used to obtain the 3D imaging of the human LA tissue at single-cell resolution.

RESULTS

With a spatial resolution of 0.32 × 0.32 × 1.0 μm³, the dataset of human LA with single-cell precision consists of two channels, each of which contains information about the bronchi and the cytoarchitecture. The bronchial wall is thicker and the lumen is smaller in the cancer tissue, in which its original normal structure is vanished. More solid components, more clustered cancer cells with larger nucleoli, and more significant atypia are found in cancer tissue. In paracancerous tissue, the bronchial wall cells have a monolayer or bilayer structure, cluster along the wall, and are relatively dispersed. Few fibrous structures and occasional dissemination of spread through air spaces (STAS) are observed.

CONCLUSIONS

Based on the human LA tissue dataset obtained by fMOST and PI staining, the bronchi and cells were reconstructed and visualized. This work provides a technical roadmap for studying the bronchus and cytoarchitectural structure and their spatial relationship in LA tissue, which may help with the understanding of the main histological structure of LA among pathologists.

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.

Accuracy and efficiency of an artificial intelligence-based pulmonary broncho-vascular three-dimensional reconstruction system supporting thoracic surgery: retrospective and prospective validation study

BACKGROUND

Anthropomorphic phantoms are used in surgical planning and intervention. Ideal accuracy and high efficiency are prerequisites for its clinical application. We aimed to develop a fully automated artificial intelligence-based three-dimensional (3D) reconstruction system (AI system) to assist thoracic surgery and to determine its accuracy, efficiency, and safety for clinical use.

METHODS

This AI system was developed based on a 3D convolutional neural network (CNN) and optimized by gradient descent after training with 500 cases, achieving a Dice coefficient of 89.2%. Accuracy was verified by comparing virtual structures predicted by the AI system with anatomical structures of patients in retrospective (n = 113) and prospective cohorts (n = 139) who underwent lobectomy or segmentectomy at the Peking University Cancer Hospital. Operation time and blood loss were compared between the retrospective cohort (without AI assistance) and prospective cohort (with AI assistance) for safety evaluation. The time consumption for reconstruction and the quality score were compared between the AI system and manual reconstruction software (Mimics®) for efficiency validation. This study was registered at https://www.chictr.org.cn as ChiCTR2100050985.

FINDINGS

The AI system reconstructed 13,608 pulmonary segmental branches from retrospective and prospective cohorts, and 1573 branches of interest corresponding to phantoms were detectable during the operation for verification, achieving 100% and 97% accuracy for segmental bronchi, 97.2% and 99.1% for segmental arteries, and 93.2% and 98.8% for segmental veins, respectively. With the assistance of the AI system, the operation time was shortened by 24.5 min for lobectomy (p < 0.001) and 20 min for segmentectomy (p = 0.007). Compared to Mimics®, the AI system reduced the model reconstruction time by 14.2 min (p < 0.001), and it also outperformed Mimics® in model quality scores (p < 0.001).

INTERPRETATION

The AI system can accurately predict thoracic anatomical structures with higher efficiency than manual reconstruction software. Constant optimization and larger population validation are required.

FUNDING

This study was funded by the Beijing Natural Science Foundation (No. L222020) and other sources.

Three-dimensional computed tomography reconstruction in video-assisted thoracoscopic segmentectomy (DRIVATS): A prospective, multicenter randomized controlled trial

OBJECTIVE

Anatomical segmentectomy has been proven to be a viable surgical treatment for small-size peripheral lung nodules. Three-dimensional (3D) reconstruction computed tomography (CT) has been proposed as an effective approach to overcome the challenges of encountering pulmonary anatomical variations when performing segmentectomy. Therefore, to further investigate the usefulness of preoperative 3D reconstruction CT in segmentectomy, we will conduct this prospective, multicenter randomized controlled DRIVATS study to compare the use of 3D reconstruction CT with standard chest CT in video-assisted segmentectomy (ClinicalTrials.gov ID: NCT04004494).

METHODS

This study began in July 2019 and a total of 190 patients will be accrued from three clinical centers within 4 years. The main inclusion criteria are patients with a single peripheral nodule 0.8-2 cm with at least one of the following requirements: (i) histology of adenocarcinoma in situ; (ii) nodule has ≥50% ground-glass appearance on CT; (iii) radiologic surveillance confirms a long doubling time (≥400 days). Surgical procedures include segmental resection of the lesion and mediastinal lymph node sampling (subsegmental resection or combined subsegmental resection will not be included in this study). The primary endpoint is operative time. The secondary endpoints include incidence of change of surgical plan, intraoperative blood loss, conversion rate, operative accident event, incidence of postoperative complications, postoperative hospital stay, length of hospitalization, duration of chest tube placement, postoperative 30-day mortality, dissection of lymph nodes, overall survival, disease-free survival, preoperative lung function, and postoperative lung function.

DISCUSSION

This multicenter DRIVATS study aims to verify the usefulness of preoperative 3D reconstruction CT compared with standard chest CT in segmentectomy. If successfully completed, this multicenter prospective study will provide a higher level of evidence for the use of 3D reconstruction CT in segmentectomy.

Progress in three-dimensional computed tomography reconstruction in anatomic pulmonary segmentectomy

The number of minimally invasive surgeries, such as video-assisted thoracoscopic surgery and robot-assisted thoracoscopic surgery, has increased enormously in recent years. More and more relevant studies report that anatomic pulmonary segmentectomy has the same effect as traditional lobectomy in the surgical treatment of early stage non-small cell lung cancer (diameter less than 2.0 cm). Segmentectomy requires sufficient knowledge of the location of the pulmonary nodules, as well as the anatomy of the target segments, blood vessels, and bronchi. With the rapid development of imaging technology and three-dimensional technology, three-dimensional reconstruction has been widely used in the medical field. It can effectively assess the vascular branching patterns, discover the anatomic variations of the blood vessels and bronchi, determine the location of the lesion, and clarify the division of the segments. Therefore, it is helpful for preoperative positioning, surgical planning, preoperative simulation and intraoperative navigation, and provides a reference for formulating an individualized surgical plan. It therefore plays a positive role in anatomic pulmonary segmentectomy. This study reviews the progress made in three-dimensional computed tomography reconstruction in anatomic pulmonary segmentectomy.

Roles and outcomes of thoracoscopic anatomic lung subsegmentectomy for lung cancer

OBJECTIVES

We performed sublobar resections, including thoracoscopic segmentectomy and subsegmentectomy for small lung cancers, and analysed the results of indications and outcomes of thoracoscopic subsegmentectomy.

METHODS

Between March 2005 and May 2020, 357 consecutive patients underwent thoracoscopic anatomic sublobar resections for lung cancer, including 68 patients undergoing subsegmentectomy. These patients were compared with 289 patients who underwent segmentectomy during the same period.

RESULTS

Subsegmentectomies included mono-/bi-/tri-subsegmentectomies for 34/23/11 of 68 patients, respectively. The median tumour size was 13.5 mm, significantly smaller than tumours in patients who underwent a segmentectomy (P < 0.001). Tumours obtained by mono-subsegmentectomy (11.0 mm) were significantly smaller than bi-/tri-subsegmentectomy (P = 0.028). The proportion of ground-glass opacity-dominant tumours obtained by subsegmentectomy (85.3%) was higher than that obtained by segmentectomy. The proportion of intentional cases satisfying the criteria for sublobar resection was higher than that of segmentectomy cases. Although tumour locations in 40 patients were not identified during surgery, tumours were correctly resected in 39 patients without tumour markers. The median operative time and blood loss were 167 min and 13 ml, significantly shorter and less, respectively, in subsegmentectomy than in segmentectomy patients (P = 0.005, P = 0.006). Duration of drainage and hospitalization were 1 and 5 days, respectively, for subsegmentectomy patients; complications occurred in 6 (8.8%). Outcomes were similar to those of the segmentectomy patients. Although 4 subsegmentectomy patients died of other diseases, none showed cancer recurrence during a mean follow-up of 50 months.

CONCLUSIONS

Thoracoscopic subsegmentectomy can be used for patients with ground-glass opacity-dominant lung cancers <1.5 cm if adequate margins can be secured.

Thoracoscopic anatomical individual basilar segmentectomy

OBJECTIVES

Thoracoscopic anatomical single or combined anatomical individual basilar segmentectomy, including subsegmentectomy, is technically challenging due to variations and the deep location of vessels and bronchi in the parenchyma. However, the long-term perioperative outcomes of various anatomical subsegmentectomy approaches have not been reported. Thus, we investigated the effectiveness of thoracoscopic basilar segmentectomy.

METHODS

We evaluated the records of 119 patients who underwent thoracoscopic single or complex basilar segmentectomy between January 2005 and December 2020 and compared the fissure and non-fissure approach for S9 and/or S10.

RESULTS

A total of 29 patients underwent single segmentectomy, and 90 patients underwent various combined anatomical segmentectomies via video-assisted thoracoscopic surgery and planning using three-dimensional simulation. There were 39 cases of S9 and/or S10 segmentectomy. The median chest tube in-dwell duration and postoperative hospital stay were 1 and 4 days, respectively. The postoperative morbidity (Clavien-Dindo grade II/IIIa) rate was 5.9% without perioperative mortality. Pathological examination revealed 83 cases of lung cancer, 21 cases of metastasis and 15 cases of benign lesions. The postoperative hospitalization duration showed significant differences in the perioperative outcomes between the fissure and non-fissure approaches for S9 and/or S10.

CONCLUSIONS

Thoracoscopic anatomical basilar individual segmentectomy has emerged as a safe and feasible procedure. The non-fissure approach enabled anatomic resection of a single segment or combined basal segments, helped avoid dissection of an incomplete fissure and facilitated surgical outcomes similar to the fissure approach.

Completion lobectomy after anatomical segmentectomy

OBJECTIVES

Completion lobectomy (CL) after anatomical segmentectomy in the same lobe can be complicated by severe adhesions around the hilar structures and may lead to fatal bleeding and lung injury. Therefore, we aimed to investigate the perioperative outcomes of CL after anatomical segmentectomy.

METHODS

Among 461 patients who underwent anatomical segmentectomy (thoracotomy, 62 patients; thoracoscopic surgery, 399 patients) between January 2005 and December 2019, data of patients who underwent CL after segmentectomy were extracted and analysed in this study.

RESULTS

Eight patients underwent CL after segmentectomy. CL was performed via video-assisted thoracic surgery in 3 patients and thoracotomy in 5 patients. In each case, there were moderate to severe adhesions. Four patients required simultaneous resection of the pulmonary parenchyma and pulmonary artery. Thoracotomy was not required after thoracoscopic surgery in any patient. Two patients experienced complications (air leakage and arrhythmia). The median duration of hospitalization after CL was 6 (range, 5-7) days. No postoperative mortality or recurrence of lung cancer was observed. All the patients with lung cancer were alive and recurrence-free at the time of publication.

CONCLUSIONS

Although individual adhesions render surgery difficult, CL after anatomical segmentectomy shows acceptable perioperative outcomes. However, CL by video-assisted thoracoscopic surgery may be considered on a case-by-case basis depending on the initial surgery.

Three-dimensional reconstruction facilitates thoracoscopic anatomical partial lobectomy by an inexperienced surgeon: a single-institution retrospective review

Background

This study aimed to evaluate the effect of three-dimensional (3D) interactive quantitative surgical planning on the outcome of video-assisted thoracoscopic surgery (VATS) anatomical partial lobectomy (APL), and to investigate the learning curve of 3D reconstruction-assisted VATS APL assisted.

Methods

We retrospectively analyzed 156 cases of solitary pulmonary ground-glass opacity (GGO) lesions in patients who underwent 3D interactive quantitative VATS APL. Digital imaging and communications in medicine data were recorded for each patient. We used Materialise 3-Matic software to make 3D reconstructed images. All surgeries were performed by the same thoracic surgeon at the Cardiothoracic Surgery Department of Yichang Central People’s Hospital between February 28, 2018, and April 20, 2020. The learning curve was evaluated using operative time and the cumulative sum (CUSUM) value of operative time in all cases.

Results

VATS APL was performed in every patient successfully, and there were no conversions to thoracotomy or lobectomy. The median surgical margin distance was 2.2 (range, 2.0–2.8) cm. All patients had an R0 complete cancer resection on histology. The histological subtypes of the segmental lesions included 69 cases of minimally invasive adenocarcinoma (MIA), 61 cases of adenocarcinoma, one case of squamous cell carcinoma, 16 cases of adenocarcinoma in situ (AIS), and nine cases of atypical adenomatous hyperplasia (AAH). The median operation time was 119 (range, 57–245) min, and median intraoperative blood loss was 37 (range, 15–247) mL. The median duration of thoracic drainage tube insertion was 2.3 (range, 1–23) days after surgery. The median length of postoperative hospital stay was 3.7 (range, 3–25) days. There were no cases of perioperative death. During the median postoperative follow-up period of 11 (range, 2–26) months, no tumor recurrence or postoperative death was observed. 3D interactive quantitative surgical planning facilitates safe and efficient VATS APL with a learning curve of 30 cases.

Conclusions

3D interactive quantitative surgical planning for VATS APL is a feasible option for inexperienced surgeons, with acceptable safety and complications.

A localization-independent approach for invisible and impalpable ground-glass opacity nodules detection in an in vitro lung specimen: two case reports

A growing number of ground-glass opacity (GGO) nodules are screened out in lungs. Small GGOs are frequently neither visible nor palpable, thus undetectable during operation. Various nodule localization techniques have been developed to facilitate the intraoperative detection of GGO nodules; however, general localization techniques are infeasible or inappropriate in some cases. The detection of small GGO is a great challenge, even within a surgical specimen in the absence of preoperative localization. A localization-independent approach for GGO detection is urgently needed. Herein, we report two cases with invisible and impalpable small GGO which were not appropriate for preoperative localization. The lesions were anatomically resected under the guidance of three-dimensional (3D) reconstruction and got an adequate margin distance. A vessel (artery, vein, or bronchus) which had advanced into or immediately adjacent to the nodule was assigned as a reference vessel. By dissecting and tracing the reference vessel from proximal to distal, the GGO lesions were successfully detected in the surgical specimens, to the eventual obtainment of an accurate pathological diagnosis. Via the two case reports, we introduced an easily handled approach, namely dissecting and tracing a reference vessel, for GGO detection. The novel approach was first described. Combined with precise anatomical segmentectomy guided by 3D reconstruction, it provides an alternative scheme for GGO resection with no need for preoperative localization.

Outcome of thoracoscopic anatomical sublobar resection under 3-dimensional computed tomography simulation

BACKGROUND

Previous studies have reported the feasibility and efficacy of thoracoscopic anatomical sublobar resection under three-dimensional computed tomography (3DCT) simulation; however, its long-term outcomes have not been clearly established in primary lung cancer. This study aimed to evaluate the long-term outcomes of this technique.

METHODS

We retrospectively reviewed data from 112 consecutive patients with selected clinical stage IA non-small cell lung cancer (NSCLC) who underwent thoracoscopic anatomical sublobar resection from 2004 to 2014. This procedure was planned using preoperative 3DCT simulation to ensure sufficient surgical margins and enabled tailor-made surgery for each patient. Patients who had predominantly ground glass opacity lung cancers underwent anatomical sublobar resection as a curative-intent resection. Other patients who were high-risk candidates for lobectomy underwent anatomical sublobar resection as a compromised limited resection.

RESULTS

Of the 112 cases, 82 had a curative-intent resection, while 30 had a compromised limited resection. Recurrence occurred in only 2 cases (1.8%), both of which were in the compromised limited group. A second primary lung cancer was observed in 5 cases (4.5%). Of the 5 patients, 4 underwent surgery for a second cancer and had no recurrence. The 5-year overall survival, lung cancer-specific overall survival, and recurrence-free survival rates were 92.5%, 100%, and 98.2%, respectively, for all cases; 97.6%, 100%, and 100%, respectively, in the curative-intent group; and 75.8%, 100% and 92.6%, respectively, in the compromised limited group.

CONCLUSIONS

Thoracoscopic anatomical sublobar resection under 3DCT simulation may be an acceptable alternative treatment in selected patients with NSCLC.

TRIAL AND CLINICAL REGISTRY

Clinical registration number: IRB No. 2020-98 (Dated: 2020.6.30).

Video-Assisted Thoracoscopic Segmentectomy for Deep and Peripheral Small Lung Cancer

Background  We aimed to retrospectively compare the long-term prognosis and recurrence after segmentectomy between nonsmall cell lung cancer (NSCLC) patients with deep and peripheral lesions.

Methods  Data were extracted for 85 lobectomy-tolerable NSCLC patients with tumors measuring ≤2 cm, who underwent video-assisted thoracoscopic segmentectomy with curative intent during January 2006 to December 2014. Tumor location was determined by the surgeon using thin-slice (1 mm) and three-dimensional computed tomography. Overall and recurrence-free survival was compared between patients with peripheral and deep lesions using univariate and multivariate Cox proportional hazard models. The indications for segmentectomy included NSCLC measuring ≤2 cm and consolidation/tumor ratio ≤20%, solid NSCLC ≤1 cm, and indeterminate nodule ≤1.5 cm.

Results  No recurrence of peripheral and deep lesions was noted. The 5-year overall survival was 96.4% for all patients, and 100 and 95.3% for patients with deep and peripheral lesions, respectively. There was no significant difference between the overall survival rates associated with the deep and peripheral lesions (95% confidence interval [CI], 89.5–98.8, nonsignificant, 86.4–98.4, respectively; p  = 0.189). In a multivariate analysis, the American Society of Anesthesiologists score (hazard ratio [HR], 13.30; 95% CI, 1.31–210.36; p  = 0.028) and histology (HR, 0.03; 95% CI, 0.00–0.32; p  = 0.037) were independent prognostic factors for overall survival; tumor location was not a prognostic factor.

Conclusions  When video-assisted thoracoscopic segmentectomy with curative intent was performed with sufficient surgical margins, the location of small NSCLC did not affect recurrence risk and prognosis. Video-assisted thoracoscopic segmentectomy for small NSCLC is acceptable, regardless of the tumor location.

Three-dimensional computed tomography angiography and bronchography combined with three-dimensional printing for thoracoscopic pulmonary segmentectomy in stage IA non-small cell lung cancer

Background

Compared with lobectomy, the anatomical structure of the lung segment is relatively complex and easy to occur variation, thus it increases the difficulty and risk of precise segmentectomy. The application of three-dimensional computed tomography bronchography and angiography (3D-CTBA) combined with a three-dimensional printing (3D printing) model can ensure the safety of operation and simplify the surgical procedure to a certain extent. We aimed to estimate the value of 3D-CTBA and 3D printing in thoracoscopic precise pulmonary segmentectomy.

Methods

We retrospectively reviewed the clinical data of 65 patients who underwent anatomical segmentectomy at the Affiliated Hospital of Shaoxing University from January 2019 to August 2020. The patients were divided into two groups: a 3D-CTBA combined with 3D printing group (30 patients) and a general group (35 patients). The perioperative data of the two groups were compared.

Results

Compared with the general segmentectomy group at the same period in our center, the surgery time of the group guided by 3D-CTBA and 3D printing was significantly shorter. Intraoperative blood loss in the 3D-CTBA and 3D printing group was also apparently lower than in the general group. Hospital stay and postoperative chest tube duration showed no significant differences between the two groups, and neither did postoperative complications such as pneumonia, hemoptysis, arrhythmia, and pulmonary air leakage.

Conclusions

3D-CTBA combined with 3D printing clearly identifies the precise pulmonary segmental structures, avoids intraoperative accidental injury, reduces intraoperative blood loss, shortens the operation time and improves the safety of thoracoscopic pulmonary segmentectomy in stage IA non-small cell lung cancer (NSCLC).

A novel fluorescent lung-marking technique using the photodynamic diagnosis endoscope system and vitamin B2

OBJECTIVES

For small pulmonary nodules that are unidentifiable by palpation or in endoscopic surgeries wherein palpation is not feasible, visualizing their location is necessary when performing pulmonary sublobar resection procedures, such as wedge resection or segmentectomy. We invented a new transbronchial lung-marking technique using the photodynamic diagnosis endoscope system and vitamin B2 and examined its feasibility and safety via porcine studies.

METHODS

We established the marking procedure in pigs and examined the marking clarity and size, fluorescence intensity and duration and possible complications. In another study, sublobar resection for virtual target lesions was performed in pigs based on the fluorescent markings. The procedure duration, marking visibility, surgical margin from the lesions and technique-related complications were assessed.

RESULTS

All 36 markings in 6 pigs were identifiable and were widely distributed over the right lung. The median diameter and fluorescence intensity at 60 min after marking were 6.0 (5.5-6.7) mm and 137.5 (122-168), respectively. All 18 markings for the 6 virtual target lesions (3 markings for each target) were clearly identified, and all target lesions were found in the resected specimens. The median duration per marking was 244 (194-255) seconds. The shortest median surgical margin from a target lesion was 11.5 (9.3-13.5) mm. No procedure-related complications were observed.

CONCLUSIONS

This novel transbronchial fluorescent lung-marking technique was useful and safe in sublobar resections for small non-palpable pulmonary lesions.

Three-dimensional reconstruction/personalized three-dimensional printed model for thoracoscopic anatomical partial-lobectomy in stage I lung cancer: a retrospective study

Background

Considering the complexity of vascular or bronchial variations and the difficulty of nodule localization during segmental resection, the three-dimensional (3D) reconstruction and printing model can provide a guarantee for safe operation and, to some extent, can simplify the surgical procedure. We conducted this study to estimate the avail of 3D reconstruction and personalized model in anatomical partial-lobectomy (APL).

Methods

We prospectively collected and retrospectively reviewed the data of 298 cases who underwent APL in our institute from April 2017 to May 2019. The patients were divided into “3D-reconstruction” group (131 patients), “3D model” group (31 patients) and “non-3D” group (136 patients). We adopted the ANOVA analysis and Chi-square test to compare the perioperative data between the three groups. Subjective satisfaction questionnaires for surgeons were provided to evaluate the value of personalized 3D printed model.

Results

The proportion of complex segmentectomy in 3D model group (87.1%) was significantly higher than that in the 3D-reconstruction group (60.3%) and non-3D group (55.9%) (P=0.006), and the average operation time of complex segmentectomy in 3D model group (99.56 minutes) was significantly shorter than that of the other group (all P<0.05). The average intraoperative blood loss in the 3D model group (12.9 mL) was significantly lower than that in the 3D reconstruction group (20.9 mL) (P=0.001) and non-3D group (18.2 mL) (P=0.022). For simple segmentectomy, the operation time, postoperative drainage, and postoperative hospital stay were similar among the three groups. The questionnaire survey showed that most surgeons were satisfied with the clinical effectiveness of the personalized 3D printed model.

Conclusions

3D printing technology can improve understanding of the anatomy, decrease the operation time, and reduce the potential risk of thoracoscopic anatomical partial lobectomy in stage I lung cancer. A pre-operative rating scale was designed to standardize the application of this technology.

Uniportal VATS approach to sub-lobar anatomic resections: literature review and personal experience

Surgical scientific literature contains relatively little information regarding the surgical outcomes of anatomic sublobar resections performed with the uniportal video-assisted thoracoscopic surgery (U-VATS) technique. This paper attempts to evaluate the role of U-VATS segmentectomies in the landscape of a minimally invasive approach to the treatment of early stage non small cell lung cancer (NSCLC).

Intracorporeal direct measurement for localizing peripheral pulmonary nodules during thoracoscopy

Background

Localizing small lung nodules during thoracoscopy is challenging for thoracic surgeons. In this case series, a novel technique for intraoperative localization that combines preoperative computed tomography (CT) with direct measurement during thoracoscopy is described.

Methods

A preoperative CT within two months before surgery was mandatory for precise planning of the resection area. During thoracoscopy, intracorporeal direct measurement (ICDM) for intraoperative localization was undergone if the targeted nodule was non-palpable and non-visualized. According to the location of the targeted nodule, longitudinal, and horizontal landmarks were chosen. The distances between the nodule and these landmarks were obtained from both CT images and intraoperative measurements during thoracoscopy. Based on the measurements, the x-axis and y-axis coordinates of the nodule were calculated and marked on the visceral pleura. A thoracoscopic wedge resection with an adequate margin was performed. From July 2014 to December 2018, ICDM was applied in 27 patients with peripheral pulmonary nodules smaller than 2 cm. Their medical records were reviewed retrospectively to evaluate the feasibility and safety of this technique.

Results

Twenty-six of the twenty-seven nodules were successfully identified (96.3%). The nodules included 13 primary lung cancers, 5 metastases, and 9 benign lesions. The median nodule size was 7 mm (range, 4-17 mm), and the median distance of the nodule from the visceral pleura was 8.1 mm (range, 1.0-31.2 mm). The median localization time was 24 minutes (range, 8-109 mm). Two patients (7.4%) had a prolonged air leak, but there was no procedure-related mortality.

Conclusions

ICDM is an effective and safe method for localizing peripheral lung nodules during thoracoscopy.

Single-port video-assisted thoracoscopic surgery subsegmentectomy: The learning curve and initial outcome

BACKGROUND

We report initial surgical results and learning process of single-port video-assisted thoracoscopic surgery (VATS) subsegmentectomy in comparison with segmentectomy in our institution as the presentative of minimal invasiveness and precise resection for early stage lung cancer.

METHODS

All patients undergoing single-port VATS sublobar anatomic resection between January 2014 and December 2018 for clinical diagnosis of lung cancer were included. The learning curve was analyzed using the cumulative summation (CUSUM) method. Comparisons were done between those who underwent single-port VATS subsegmentectomy and segmentectomy.

RESULTS

A total of 364 patients underwent single-port VATS segmentectomy and 91 patients underwent single-port VATS subsegmentectomy were included. Lung adenocarcinoma was the most common (61.1%) diagnosis. The operative time and blood loss in the subsegmentectomy group were less than the segmentectomy group. The incidence of intraoperative complication was also lower in the subsegmentectomy group. The surgical proficiency was reached at 28 cases in single-port VATS subsegmentectomy. For primary lung cancer, the tumor size in subsegmentectomy group was smaller than segmentectomy group (1.1 cm versus 1.4 cm, p = 0.026). The resection margin was smaller in subsegmentectomy group, and both groups reached adequate margin without significant difference (94.7% versus 95.5%, p = 0.737). During the follow-up period, 2 (3.5%) patients in subsegmentectomy group and 9 (4.1%) patients in segmentectomy group developed distant metastasis.

CONCLUSION

Single-port VATS subsegmentectomy is safe and feasible for small-sized lung lesion, providing the benefit of minimal invasiveness, preservation of pulmonary function, and clearance of lymphatic drainage at the intersegmental plane. The surgical proficiency could be achieved based on the experiences in single-port VATS segmentectomy.

[Advances in the Study of the Effects of Video-assisted Thoracoscopic Segmentectomy on Pulmonary Function]

2018年美国国立综合癌症网络关于非小细胞肺癌（non-small cell lung cancer, NSCLC）指南指出，对于早期NSCLC，解剖性肺叶切除为首选方案。随着电视胸腔镜技术的发展，以胸腔镜为代表的胸外科微创手术在临床得到了广泛应用。胸腔镜肺段切除术已经成为早期NSCLC的治疗方案之一。临床研究发现相较于肺叶切除，亚肺叶切除在早期NSCLC治疗中也可取得相似的结果并保留更多的肺功能，但肺段切除术后患者肺功能的改变尚存争议。本文将重点对胸腔镜肺段切除术后患者肺功能改变的研究进展做一综述。

Robotic Approach to Combined Anatomic Pulmonary Subsegmentectomy: Technical Aspects and Early Results

BACKGROUND

Minimally invasive techniques are increasingly being used in pulmonary segmentectomy and combined subsegmentectomy. However, there are no reports as yet on robotic combined anatomic subsegmentectomy (CAS). In this report, we describe related clinical data and operative techniques and present our early results.

METHODS

Clinical data of patients undergoing robotic CAS were retrospectively reviewed. A combined subsegmentectomy was defined as the resection of 2 or more subsegments that involved 2 or more adjacent segments. The study enrolled patients who underwent completely portal robotic CAS.

RESULTS

Between May 2015 and January 2018, a single surgeon performed completely portal robotic CAS for 16 patients. In the CAS-treated patients, 75% of the lesions were located in the right upper lobe, and none required conversion to thoracotomy. Median operative time was 175 minutes (range, 75 to 294 minutes), and mean postoperative hospital stay was 4 days (range, 2 to 11 days). Although 1 patient experienced a prolonged air leak, the other 15 recovered uneventfully. Within a median follow-up period of 15 months, there were no deaths or tumor recurrences.

CONCLUSIONS

Completely portal robotic CAS is a safe and effective procedure in a select subset of patients, proving quite suitable for smaller (<2 cm) multisegment lung cancers, particularly lesions of the right upper lobe. A robotics approach facilitates complex and challenging CAS, the disadvantage being lengthy operative times during early acquisition of skills.

Preoperative 3-dimensional computed tomography lung simulation before video-assisted thoracoscopic anatomic segmentectomy for ground glass opacity in lung

Background

Three-dimensional (3D) simulation of pulmonary vessels and the space between the lesion and adjacent tissues may improve the safety and accuracy of video-assisted thoracoscopic surgery (VATS) for lung. The aim of this study was to evaluate the effect of 3D simulation on the outcome of VATS segmentectomy for ground glass opacity (GGO) in lung.

Methods

We retrospectively analyzed 68 cases of small (≤2 cm) GGO, which were diagnosed as cT1aN0M0 lung cancer, from May 1, 2016 to February 28, 2017 in our institute. All the patients underwent VATS segmentectomy. The patients were divided into "3D" group, 3D preoperative reconstruction simulation in 36 patients and "non-3D" group, 32 patients with only computed tomography (CT). Operation plans were firstly made by CT in all patients, then by 3D simulation only in 3D group. The clinical outcomes, including operation time, blood loss, resection margin distance, length of postoperative stay and postoperative complications were compared between the two groups.

Results

There were 21 male and 47 female analyzed, aging from 34 to 72 years (median 57). In 3D group, pathological result showed 8 cases of adenocarcinoma, 23 cases of microinvasive adenocarcinoma (MIA), 5 cases of adenocarcinoma in situ (AIS). In non-3D group, 18 cases of MIA, 9 cases of adenocarcinoma and 5 cases of AIS were diagnosed pathologically. The blood loss, postoperative hospital stay and the incidence of the postoperative complications were similar in both of the groups. There was no 30-day postoperative mortality in either group. The median operation time for the 3D group (111 minute) was shorter than non-3D group (139 minute) (P=0.03). Seven cases (19%) in 3D group changed the original operation plan according to the simulation result with the consideration of adequate resection margin distance. All cases in 3D group had adequate resection margin distance. Four cases (13%) in non-3D group got inadequate resection margin distance, and more lung tissues than the original plan were then resected in these patients (P=0.04).

Conclusions

3D preoperative simulation may be more precise in operation plan than CT scan and can significantly shorten the operation time in VATS segmentectomy for GGO in lung.

VATS segmentectomy: past, present, and future

Video-assisted thoracoscopic surgery (VATS) has gradually been implemented in thoracic surgery, and the VATS approach has now been extended to technically challenging procedures, such as segmentectomy. The definition of VATS segmentectomy is changing over time, and the repertoire of segmentectomy is getting wider with increasing reports on atypical segmentectomy. VATS segmentectomy bears surgical, oncological, and technical advantages; however, there are still areas of controversy, particularly regarding oncological outcomes. The indication of VATS segmentectomy is diverse and is used for treating lung cancer, metastatic lung tumors, or a variety of nonmalignant diseases. It is particularly valuable for the lung-sparing resection of deeply located small nodules or repeated surgery for multiple lung lesions. VATS segmentectomy requires a thorough analysis of segmental anatomy and a tailored preoperative planning with the assessment of surgical margins. Technical challenges include intraoperative navigation, methods to identify and dissect the intersegmental plane, and the prevention of air leakage. This review will discuss the present state of VATS segmentectomy, with a focus on past studies, current indications and techniques, and future view.