A novel video-assisted anatomic segmentectomy technique: selective segmental inflation via bronchofiberoptic jet followed by cautery cutting

Right upper lobectomy for lung cancer associated with a displaced anomalous bronchus: two case reports

BACKGROUND

Bronchial bifurcation abnormalities are often discovered incidentally on chest computed tomography or bronchoscopy. As this condition is asymptomatic, it has little effect on the disease course of patients with lung cancer. However, this abnormality must be considered when performing lung resection.

CASE PRESENTATION

Patient 1 was a 73-year-old man with suspected simultaneous triple lung cancers [cT1c (3) N0M0, Stage IA3] in the right and left upper lobes. He was initially scheduled to undergo right upper lobectomy and systematic nodal dissection. Chest computed tomography revealed a displaced B3 that arose from the right middle lobe bronchus. V1+2 was transected first, followed by the superior truncus of the pulmonary artery, and B1+2, respectively. After the branches of V3 were ligated, B3 was identified smoothly. Finally, the incomplete interlobar fissure between the upper and middle lobes was separated using an auto-stapler. No vascular abnormalities were observed. Patient 2 was a 62-year-old woman with suspected lung cancer (cT1cN0M0, Stage IA3) in the right upper lobe, and was scheduled to undergo right upper lobectomy and lobe-specific nodal dissection. Chest computed tomography revealed a right top pulmonary vein and a displaced B1 that arose from the right main bronchus independently. Because V1+3 was resected simultaneously during upper and middle lobe resection during robot-assisted thoracic surgery, the procedure was cool-converted to video-assisted thoracic surgery. An independently A1 was observed, followed by A2b and A3, which branched off as a common stem. A right top pulmonary vein was smoothly detected. Each blood vessel was transected using an auto-stapler. B2+3 was transected first using an auto-stapler, followed by B1.

CONCLUSIONS

The displaced anomalous bronchus is often accompanied by pulmonary arterial or venous abnormalities and an incomplete interlobar fissure. A "hilum first, fissure last" technique is often useful. Preoperative evaluation and surgical planning are important.

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.

Bibliometric analysis of the top 100 highly cited articles on sublobectomy for non-small cell lung cancer

OBJECTIVES

The goal of this research is to pinpoint the top 100 most frequently referenced studies on sublobectomy for non-small cell lung cancer.

METHODS

We identified the top 100 most frequently referenced studies on sublobectomy for non-small cell lung cancer by searching the Web of Science database. We extracted key information from the selected studies, including the author, journal, impact factor, type of article, year of publication, country, organization, and keyword.

RESULTS

To the best of our understanding, this is the inaugural bibliometric study on sublobectomy for non-small cell lung cancer. The publication years of the top 100 most frequently referenced studies span from 1994 to 2022, with citation counts ranging from 51 to 795. The majority of the included studies are original (93/100) and primarily retrospective studies (82/93). The United States leads in terms of published articles and citations, with the Annals of Thoracic Surgery being the most frequently sourced journal (n = 27). High-density keywords primarily originate from limited resection, lobectomy, survival, carcinoma, recurrence, randomized trial, radiotherapy, lung cancer, outcome, 2 cm, as revealed by CiteSpace analysis.

CONCLUSIONS

Our research compiles and analyzes the top 100 most frequently referenced studies in the field of sublobectomy for non-small cell lung cancer. The United States has the most published and cited works on this topic. Currently, the hot keywords for sublobectomy research are gradually shifting towards prognosis and obtaining better evidence-based medical evidence to demonstrate its value in the treatment of non-small cell lung cancer.

Uniportal Video-Assisted Thoracoscopic Segmentectomy for Early-Stage Non-Small Cell Lung Cancer: Overview, Indications, and Techniques

Twenty years have passed since uniportal video-assisted thoracoscopic surgery (VATS) was first reported. Several reports have already proven the minimal invasiveness of uniportal VATS. In addition, two large clinical trials recently demonstrated the benefits of segmentectomy for small peripheral early-stage non-small cell lung cancer. Uniportal VATS segmentectomy is considered the most beneficial minimally invasive surgery for patients with early-stage lung cancer. However, a high level of skill and experience are required to achieve this goal. Only a few reports have discussed specific techniques, particularly for complex segmentectomies. In this Special Issue, we reviewed previous reports on uniportal VATS segmentectomy regarding the indications, instrument selection, marking of the tumor location, methods of intersegmental plane identification, and lymph node dissection, including our own techniques with video content.

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.

Application of microwave surgical instrument to lung segmentectomy for small-sized lung cancer

Objectives

For lung segmentectomy of small lung cancers, we used a microwave surgical instrument for lung parenchymal dissection mainly at the pulmonary hilum, which is difficult to handle with surgical staplers. This technique facilitated the insertion of staples.

Methods

In total, 116 patients with cStage 0-1A3 non-small cell lung cancer who underwent lung segmentectomy were included in this study. We compared the perioperative factors of the group in which a microwave surgical instrument was used for dissection procedures, including lung parenchymal dissection at the pulmonary hilum, and peripheral intersegmental dissection was performed with surgical staplers (group M+S: N = 69), with those of the group in which parenchymal dissection was performed mainly with surgical staplers without using the microwave surgical instrument (group S: N = 47).

Results

Although more complex segmentectomies were performed in the M+S group (P = .001), the number of staple cartridges (7 staple cartridges vs 8 staple cartridges, P = .005), the surgical times (179 vs 221 minutes, P < .0001), and the blood loss (5 mL vs 30 mL, P = .012) were significantly lower in the M+S group. The duration of chest tube placement was significantly shorter in the M+S group (P = .019), and postoperative complications of grade 2 or greater were significantly lower in the M+S group (P = .049).

Conclusions

The effective use of the microwave surgical instrument combined with surgical staplers can simplify pulmonary hilar and intersegmental plane dissections not only for simple segmentectomy but also for complex segmentectomy, leading to favorable intraoperative and postoperative outcomes.

Sublobar resection or lobectomy and postoperative respiratory complications in emphysematous lungs

OBJECTIVES

Pulmonary resection in patients with severe emphysema may impact postoperative respiratory complications. Low-attenuation areas evaluated using three-dimensional computed tomography to assess emphysematous changes are strongly associated with postoperative respiratory complications. Herein, we investigated the relationship between low-attenuation area, the surgical procedure and resected lung volume, which has not been explored in previous studies.

METHODS

We retrospectively evaluated patients with primary or metastatic lung cancer who underwent surgical resection. The low-attenuation area percentage (low-attenuation area/total lung area × 100) and resected lung volume were calculated using three-dimensional computed tomography software, and the relationship with postoperative respiratory complications was analysed.

RESULTS

Postoperative respiratory complications occurred in 66 patients (17%) in the total cohort (n = 383). We set the median value of 1.1% as the cut-off value for low-attenuation area percentage to predict postoperative respiratory complications, which occurred in 24% and 10% of patients with low-attenuation area >1.1% and <1.1%, respectively (P < 0.001). Postoperative respiratory complications occurred in approximately one-third of the patients with low-attenuation area >1.1%, whose resected lung volume was ≥15.8% or ≥5 resected subsegments. Multivariable analysis revealed that sublobar resection was associated with a significantly lower risk of postoperative respiratory complications in patients with low-attenuation area >1.1% (odds ratio 0.4, 95% confidence interval 0.183-0.875).

CONCLUSIONS

Emphysema is a risk factor for postoperative respiratory complications, and lobectomy is an independent predictive risk factor. Preserving more lung parenchyma may yield better short-term prognoses in patients with emphysematous lungs.

Bronchial branching patterns and volumetry in the right upper lobe: impact on segmentectomy planning

OBJECTIVES

The use of segmentectomy is expected to increase. However, understanding of the segmental bronchial branching is limited. Herein, we aimed to investigate bronchial branching pattern complexity and segmental volumetry of the right upper lung lobe to develop an accurate understanding of segmental anatomy and contribute to the advancement of safe and efficient lung segmentectomy.

METHODS

We evaluated chest computed tomography scans of 303 patients and categorized the branching of segmental bronchi (segment 1, apical; segment 2, posterior; and segment 3, anterior) into 4 major types (typical trifurcated, bifurcated non-defective, bifurcated defective and atypical trifurcated) and 11 subtypes. Segmental volumetry was performed to determine the predominant segment in each case (volume difference <5% was considered equal). Branching complexity was evaluated separately for volumetry-predominant and volumetry-non-predominant segments.

RESULTS

Trifurcated non-defective was the most frequent branching type (64.4%), followed by bifurcated non-defective (22.1%), bifurcated defective (8.6%) and trifurcated half-defective (4.0%). In terms of segmental volumetry, most cases had a one-segment-predominant distribution (71%) and only 5% of cases had equal distribution (segment 1 = segment 2 = segment 3). More than half of the cases had a segment 3-predominant distribution (52%). Branching complexity analysis revealed that the volumetry-non-predominant segment was associated with a higher risk of complex branching patterns compared with the volumetry-predominant segment (37% vs 19%, respectively; P < 0.005).

CONCLUSIONS

Volumetric assessment of the right upper lobe showed a heterogeneous segmental volume distribution. Care should be taken during lung segmentectomy of the volumetry-non-predominant segments because of the high risk associated with complex bronchial branching patterns.

CLINICAL TRIAL REGISTRATION

No. 4840.

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.

An optimal thoracoscopic segmentectomy approach: Combined ultra-high-definition 4K endovision systems with "no-waiting" technique in S8-9 complex segmentectomy

Thoracoscopic segmentectomy might be an alternative to lobectomy for small size lung cancer. Precise identification of the pulmonary intersegmental plane was needed for an optimal segmentectomy. Recently, (1) the ultra-high-definition 4K systems had claimed to overcome the lack of depth perception by secondary visual cues; (2) the no-waiting procedure was induced as an alternative and optimized method for identifying the plane. It was unclear whether combined ultra-high-definition 4K endovision systems with "no-waiting" technique in thoracoscopic segmentectomy could achieve an excellent result. A 68-year-old female patient was admitted into our hospital for occasional pulmonary nodule during her routine physical examination. The nodule is located between S8 and S9 segment, and was suspected to be an early-stage lung cancer. She underwent a thoracoscopic S89 complex segmentectomy using ultra-high-definition 4K endovision systems and "no-waiting" surgical technique. The intersegmental plane was clearly detected and easily treated by the endoscopic linear cutting staplers. The patient recovered well and was discharged without complications. Combining ultra-high-definition 4K endovision systems with "no-waiting" technique seems to be an optimal thoracoscopic segmentectomy approach for the management of lung cancers.

Use of a radiofrequency identification system for precise sublobar resection of small lung cancers

BACKGROUND

The incidence of sublobar resection is increasing because of the rise in the detection of small lung cancers. However, local recurrence needs to be addressed, and several methods are needed for the resection with secure margins of non-visible and non-palpable tumors.

METHODS

We retrospectively reviewed the use of a radiofrequency identification (RFID) system in sublobar resection of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) at our institute.

RESULTS

From June 2020 to June 2022, 39 patients underwent sublobar resection for AIS or MIA. The median age was 69 years (interquartile range, 64-76). Among the 39 patients, 24 were diagnosed with AIS and 15 with MIA. Segmentectomy, subsegmentectomy, and wedge resection were performed in nine, six, and 24 patients, respectively. The median size of the target tumor was 9.0 mm (8.1-12.9) and the median distance between the tag and the tumor was 2.9 mm (0-7.5). The median pathological surgical margin was 15.0 mm (10-17.5). Complete resection of all lesions was performed with a secure surgical margin. The median follow-up duration was 6 months, during which no local recurrence was detected in any of the patients.

CONCLUSIONS

The RFID marking system accurately informed the surgeons of the tumor location and helped them to perform precise sublobar resection.

Tumour location predicts occult N1 nodal metastasis in clinical stage I non-small-cell lung cancer

OBJECTIVES

Pathological lymph node metastases are often observed in patients with clinical N0 lung cancer. Identifying preoperative predictors of occult hilar nodal metastasis (OHNM) is important in determining the surgical procedure in patients with clinical stage I non-small-cell lung cancer. This study aimed to determine the frequency and predictors of OHNM by tumour location in these patients.

METHODS

Between April 2007 and May 2019, data of patients who underwent lobectomy or segmentectomy for clinical stage I pure-solid non-small-cell lung cancer were retrospectively reviewed. The ratio of the distance from the pulmonary hilum to the proximal side of the tumour to the distance from the pulmonary hilum to the visceral pleural surface through the centre of the tumour, named 'distance ratio (DR)', was calculated. The relationship of the DR with clinicopathological findings and prognosis was discussed.

RESULTS

A total of 357 patients were enrolled. OHNM frequency was 14.6%. Patients were divided into 2 groups based on whether the DR was ≤0.67 (central type) or >0.67 (peripheral type). The frequency of OHNM was significantly higher in the DR ≤0.67 group (21.5% vs 7.4%; P < 0.001). Multivariable analysis revealed that DR was the only independent preoperative predictor of OHNM (odds ratio, 3.63; 95% confidence interval, 1.83-7.18; P < 0.001).

CONCLUSIONS

The frequency of OHNM was significantly lower in peripheral-type lung cancer; therefore, tumour location was the most important preoperative predictor of OHNM.

Dual Image Navigation to Secure Surgical Margins in Thoracoscopic Segmentectomy

PURPOSE

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of various lung intersegmental plane identification methods

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

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.

Thoracoscopic "cut-through" segmentectomy for small-sized lung cancer in a deep central location

The use of segmentectomy and subsegmentectomy for the management of lung lesions is well established. However, the use of subsegmentectomy for deep seated lesions in the upper lobe is difficult because of sufficient surgical margins. Here, we present a patient whose lung lesion was in a deep central area and at the borders of three segments in the upper lobe of the right lung. We used combined subsegmentectomy (S1b + S3a) video-assisted thoracoscopic surgery for this small-sized lung cancer in a deep central location.

Comparison of oncological outcomes between trisegmentectomy and lobectomy for non-small cell lung cancer in the left upper division

Background

The left upper lobe is one of the largest lobes in the lungs and is divided into two anatomical units: the upper division (segments 1+2 and segment 3) and lingula (segments 4 and 5). This anatomical classification is similar to that used for the right upper and middle lobes. Although bilobectomy is not recommended for right upper or middle lobe tumors close to the interlobar plane, lobectomy is often performed for tumors located close to the intersegmental plane in the left upper division. To aid in establishing trisegmentectomy as a standard treatment for clinical N0 non-small cell lung cancer (NSCLC) in the left upper lobe, we aimed to re-assess its feasibility based on oncological outcomes according to tumor location.

Methods

We retrospectively analyzed the data of patients with clinical N0 NSCLC in the left upper division who underwent left upper lobectomy or trisegmentectomy between April 2006 and December 2020. After propensity score matching, oncological outcomes were compared between the trisegmentectomy and lobectomy groups. To verify whether trisegmentectomy was indicated regardless of tumor distance from the intersegmental plane, we compared the recurrence-free survival (RFS) rates following trisegmentectomy between patients with tumors ≤20 and >20 mm from the intersegmental plane.

Results

After propensity score matching, 46 patients were included in each group. There was no significant difference in the 5-year RFS rate between the lobectomy and trisegmentectomy groups (75.5% vs. 84.0%, P=0.41). In the trisegmentectomy cohort, the 5-year RFS rate did not significantly differ according to tumor distance from the intersegmental plane (≤20 or >20 mm) measured using three-dimensional computed tomography (79.4% vs. 81.2%, P=0.69). Multivariate analysis indicated that tumor distance from the intersegmental plane was not a significant predictor of RFS (hazard ratio: 1.75, 95% confidence interval: 0.52-5.91, P=0.37).

Conclusions

Our analysis suggests that oncological outcomes (i.e., RFS rates) following trisegmentectomy for clinical N0 NSCLC in the left upper division are not significantly inferior to those following lobectomy, even if the tumor is located close to the intersegmental plane.

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.

Clinical application of bronchial high-frequency ventilation in 2-port thoracoscopic segmentectomy

To evaluate the safety and clinical application of a computer-aided surgery system (CAS) combined with high-frequency bronchial ventilation in 2-port thoracoscopic anatomical segmentectomy. A total of 301 patients who underwent 2-port thoracoscopic segmentectomy between January 1, 2019 and March 1, 2022 in the 960th Hospital of the People's Liberation Army and the Department of Thoracic Surgery of Zibo Municipal Hospital were retrospectively analyzed. The experimental and control groups were created according to the different methods of appearing the intersegmental plane of the lung. The experimental group comprised 152 patients who underwent CAS reconstruction combined with high-frequency ventilation, and the control group comprised 149 patients who underwent CAS reconstruction combined with expansion collapse. The characteristics of the patients, including age, sex, smoking history, forced expiratory volume in 1 second/forced vital capacity, Maximal ventilation, diameter of pulmonary nodules, intraoperative blood loss, postoperative drainage volume, drainage tube removal time, length of hospital stay after extubation, postoperative complication rate, operation time and appearance time of the intersegmental plane, were compared between the 2 groups. All patients completed the operation between high-frequency bronchial ventilation and expansion collapse group. There was no significant difference in Forced expiratory volume in 1 second/Forced vital capacity [(101.05 ± 11.86) vs (101.86 ± 11.61)], maximum expiratory volume [(86.36 ± 17.59 L) vs (85.28 ± 17.68 L)], the diameter of lung nodules [(13.61 ± 3.51 cm) vs (13.21 ± 3.41 cm)], intraoperative blood loss [(47.50 ± 45.90 mL) vs (48.49 ± 34.65 mL)], postoperative drainage volume [(425.16 ± 221.61 mL) vs (444.70 ± 243.72 mL)], drainage tube removal time [(3.88 ± 1.85 days) vs (3.43 ± 1.81 days)], or postoperative hospital stay [(6.07 ± 2.14 days) vs (5.82 ± 1.88 days) between the experimental group and the control group (P > .05)]. There were significant differences in operation time [(95.05 ± 26.85 min) vs (117.85 ± 31.70 min), P = .017] and intersegmental plane appearance time [(2.37 ± 1.03 min) vs (14.20 ± 3.23 min), P < .001]. High-frequency bronchial ventilation is safe and feasible when used in quickly and accurately identifying the intersegmental plane and is worthy of clinical application in 2-port thoracoscopic segmentectomy.

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.

Near-infrared fluorescence guided surgery: State of the evidence from a health technology assessment perspective

Different applications of near-infrared fluorescence-guided surgery are very promising, and techniques that help surgeons in intraoperative guidance have been developed, thereby bridging the gap between preoperative imaging and intraoperative visualization and palpation. Thus, these techniques are advantageous in terms of being faster, safer, less invasive, and cheaper. There are a few fluorescent dyes available, but the most commonly used dye is indocyanine green. It can be used in its natural form, but different nanocapsulated and targeted modifications are possible, making this dye more stable and specific. A new active tumor-targeting strategy is the conjugation of indocyanine green nanoparticles with antibodies, making this dye targeted and highly selective to various tumor proteins. In this mini-review, we discuss the application of near-infrared fluorescence-guided techniques in thoracic surgery. During lung surgery, it can help find small, non-palpable, or additional tumor nodules, it is also useful for finding the sentinel lymph node and identifying the proper intersegmental plane for segmentectomies. Furthermore, it can help visualize the thoracic duct, smaller bullae of the lung, phrenic nerve, or pleural nodules. We summarize current applications and provide a framework for future applications and development.

Intraoperative Identification of the Intersegmental Plane: From the Beginning to the Future

Segmentectomy has played a crucial role in the treatment of early-stage lung cancer after the publication of JCOG0802, which indicated that patients with small-sized peripheral non-small-cell lung cancer could receive better survival from segmentectomy than lobectomy despite a higher local recurrence. The intraoperative identification of the intersegmental plane ensures complete resection of the lesion with sufficient margin so that it is deemed as the critical part of segmentectomy. Diverse methods have been developed to acquire distinguishable and lasting borderline between segments, but none of them is proved perfect. In this review, we searched and classified these techniques that emerged from the beginning when segmentectomy was used for bronchiectasis until now. Comparisons between different ways in mechanisms, facility, and safety were made to depict a comprehensive landscape for surgeons to select fit one. Furthermore, we presented our vision for the future of intersegmental plane identification.

Comparison of stapler and electrocautery for division of the intersegmental plane in lung segmentectomy

Background

We retrospectively compared the use of a stapler and electrocautery for division of the intersegmental plane during pulmonary segmentectomy.

Methods

We enrolled 156 patients who underwent pulmonary segmentectomy in our department between March 2006 and August 2020. The patients were divided into electrocautery (n=62) and stapler (n=94) groups based on the device used to divide the intersegmental plane. Patient characteristics, perioperative outcomes, and ratios of actual (calculated using software) to predicted (calculated by counting the resected segments) lung volumes were compared between the two groups. Additionally, we used multivariate analysis to identify the factors that contributed to the incidence of postoperative air leakage after cut-off value was set by receiver operating characteristic (ROC) curve analysis. Moreover, a subset analysis was performed based on the type of segmentectomy (common or uncommon). Common segmentectomies included resection of the basilar or superior segment of the lower lobe, or lingular or upper division of the left upper lobe; all other segmentectomies were classified as uncommon.

Results

Compared to the electrocautery group, the stapler group had shorter operative times (P=0.0027), duration of postoperative drainage (P=0.00037), and duration of postoperative hospitalization (P=0.0021). Moreover, incidence of postoperative ≥3 days drainage was significantly reduced in the stapler group (P=0.003). There were no significant differences between the stapler and electrocautery groups in the actual:predicted lung volumes at 6 months (1.01 and 1.04, respectively; P=0.28) or 12 months (1.06 and 1.07, respectively; P=0.68) after surgery. Preoperative lung volume was significantly correlated with preoperative vital capacity (VC) (γ=0.69; P<0.001) and forced expiratory volume in 1 second (FEV₁) (γ=0.48; P<0.001). The multivariate analysis indicated that the use of stapler for division of intersegmental plane was the only factor that contributed to reducing the incidence of postoperative ≥3 days drainage (P=0.0027, odds ratio: 0.23, 95% CI: 0.086–0.597). In a subset analysis of uncommon segmentectomy, there were no significant differences among the groups in most perioperative results.

Conclusions

Compared to electrocautery, the use of a stapler for division of the intersegmental plane was associated with better perioperative outcomes, especially reduction of postoperative drainage time, and similar postoperative remnant lung volumes and function.

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.

A narrative review of fluorescence imaging in robotic-assisted surgery

Objective

In this review, we provide examples of applications of fluorescence imaging in urologic, gynecologic, general, and endocrine surgeries.

Background

While robotic-assisted surgery has helped increase the availability of minimally invasive procedures across surgical specialties, there remains an opportunity to reduce adverse events associated with open, laparoscopic, and robotic-assisted methods. In 2011, fluorescence imaging was introduced as an option to the da Vinci Surgical System, and has been standard equipment since 2014. Without interfering with surgical workflow, this fluorescence technology named Firefly^® allows for acquisition and display of near-infrared fluorescent signals that are co-registered with white light endoscopic images. As a result, robotic surgeons of all specialties have been able to explore the clinical utility of fluorescence guided surgery.

Methods

Literature searches were performed using the PubMed and MEDLINE databases using the keywords "robotic-assisted fluorescence surgery", "ICG robotic surgery", and "fluorescence guided surgery" covering the years 2011-2020.

Conclusions

Real-time intraoperative fluorescence guidance has shown great potential in helping guide surgeons in both simple and complex surgical interventions. Indocyanine green is one of the most widely-used imaging agents in fluorescence guided surgery, and other targeted, near-infrared imaging agents are in various stages of development. Fluorescence is becoming a reliable tool that can help surgeons in their decision-making process in some specialties, while explorations continue in others.

Electrocautery vs. Stapler in Comparing Safety for Segmentectomy of Lung Cancer: A Meta-Analysis

Background: Electrocautery and staplers are regarded as the two most common surgical instruments for dissecting the intersegmental plane in segmentectomy. We performed a meta-analysis to compare electrocautery and staplers in terms of their safety and effects.

Methods: A systematic search strategy was performed using PubMed, and the retrieval time was up to April 1, 2020. Odds ratio (OR) and mean differences (MDs) with 95% CI were applied to determine the effectiveness of dichotomous or continuous variables, respectively.

Results: Six studies including 385 patients were included. The electrocautery had a higher incidence rate of postoperative complication [OR= 1.92, 95% CI (1.12, 3.28), P = 0.02)] and air leak [OR: 3.91, 95% CI (1.64, 9.35), P = 0.002)]. No significant difference was found in the comparison of surgery time, blood loss, and duration of tube days or hospitality days.

Conclusions: Our study indicated that patients under segmentectomy were associated with better safety by using stapler than electrocautery in the reduction of postoperative complications.

Video-Assisted Thoracic Surgery Segmentectomy

Although lobectomy remains the gold-standard surgical treatment for non-small-cell lung cancer, the frequency of thoracoscopic segmentectomy is increasing. Multiple factors must be considered in the choice of the procedure, ranging from adequate surgical planning or simulation, tumor localization, and identification of the intersegmental plane to severing the intersegmental plane to achieve an oncologically safe surgical margin with no or minimal manual palpation and different landmarks. In this article, we present an overview of methods for each procedural step of thoracoscopic segmentectomy, from preoperative planning to division of the intersegmental plane.

Predictors of failure of intersegmental line creation using bronchoscopic jet ventilation for thoracoscopic pulmonary segmentectomy

BACKGROUND

During pulmonary segmentectomy, identification of the target segment is essential. We used bronchoscopic jet ventilation (BJV) to delineate the intersegmental plane by selectively sending air into the target segment. The purpose of this study was to investigate the factors associated with BJV failure.

METHODS

Data were retrospectively collected from 48 patients who underwent pulmonary segmentectomy with BJV between March 2014 and May 2019 at a single center. Data were compared between BJV succeeded cases and failed cases.

RESULTS

In 13 cases (27%), BJV were unsuccessful. The Brinkman index was significantly higher in failed cases (962 ± 965 failed vs. 395 ± 415 successful, P = 0.0067). The success rate was significantly lower when BJV was applied to the posterior basal segmental bronchus (B10) (B10: 1/5 (20%) vs others: 34/43 (79%), P = 0.015).

CONCLUSION

Long-term smoking and the bronchus corresponding to the posterior basal segment might make successful performance of BJV difficult.

Clinical Behavior of Combined Versus Pure High-Grade Neuroendocrine Carcinoma

BACKGROUND

The aim of this study was to investigate and compare the clinical behaviors of combined and pure high-grade neuroendocrine carcinoma (large-cell neuroendocrine carcinoma [LCNEC] and small-cell lung carcinoma [SCLC]).

PATIENTS AND METHODS

Data of 132 patients who underwent complete resection for combined or pure high-grade neuroendocrine carcinoma (combined group, 67; pure group, 65) between January 2001 and December 2015 were retrospectively reviewed. The clinicopathological features were analyzed and compared, and the prognoses were assessed by performing the Kaplan-Meier method and Cox regression analysis.

RESULTS

The combined and pure groups had nearly equivalent clinicopathological characteristics, specifically, older males with smoking history, almost the same percentage of pleural/lymphatic/vascular invasion, and nearly the same recurrence rates and relapse patterns. The combined group had prognosis equivalent to that of the pure group (5-year overall survival [OS] rates: 61.8% vs. 52.2%, respectively; P = .82 and 5-year recurrence-free survival [RFS] rates: 42.4% vs. 43.9%, respectively; P = .96), and this trend was identified in sub-analyses only for patients with LCNEC, SCLC, and the same pathological stage. Multivariable Cox regression analysis in patients with high-grade neuroendocrine carcinoma revealed that vascular invasion and pathological stage were independent prognostic factors for OS; more importantly, combined and pure histologies were proven to have nearly equivalent associations with prognosis (hazard ratio, 0.96; 95% confidence interval, 0.22to 1.66; P = .96).

RESULTS

Combined high-grade neuroendocrine carcinoma had clinical behavior equivalent to those of pure high-grade neuroendocrine carcinoma, with similar clinicopathological characteristics.

Application of Mimics Medical 21.0 software in thoracoscopic anatomical sublobectomy

BACKGROUND

The anatomical structure of pulmonary segments is complex, and there are many anatomical variations, making the operation more difficult, so we used Mimics Medical 21.0 software for three-dimensional computed tomography bronchography and angiography (3D-CTBA), carefully formulated the surgical plan and on this basis completed the video-assisted thoracoscopic anatomical sublobectomy.

METHODS

A total of 38 patients with pulmonary nodules were selected and received video-assisted thoracoscopic anatomical sublobectomy after using Mimics Medica 21.0 software for 3D-CTBA.

RESULTS

The mean operative duration was 158.42±20.21 minutes, and the operative hemorrhage was 97.66±22.37 mL. In pathological diagnoses, there were 5 benign cases (13.2%), 9 cases with atypical adenomatous hyperplasia (23.7%), 12 cases with adenocarcinoma in situ (31.6%), 11 cases with minimally invasive adenocarcinoma (28.9%) and 1 case with invasive adenocarcinoma (2.6%); 8.29±0.98 lymph nodes sampled had no metastasis. The chest tube drainage duration and postoperative hospitalstay were 2.47±0.73 days and 5.47±0.73 days, respectively.

CONCLUSIONS

Using Mimics Medical 21.0 software can quickly and accurately complete 3D-CTBA, which is beneficial to formulate a personalized anatomical sublobectomy surgical plan.

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.

Fluorescence visualization of the intersegmental plane by bronchoscopic instillation of indocyanine green into the targeted segmental bronchus: determination of the optimal settings

Objective

To determine the appropriate amount of indocyanine green for bronchial insufflation.

Methods

We enrolled 20 consecutive patients scheduled for anatomical segmentectomy in the Kochi Medical School Hospital. After inducing general anesthesia, 6 to 60 mL of 200-fold-diluted indocyanine green (0.0125 mg/mL) was insufflated into the subsegmental bronchi in the targeted pulmonary segmental bronchus. The volume of the targeted pulmonary segments was calculated using preoperative computed tomography. Fluorescence spread in the segmental alveoli was visualized using a dedicated near-infrared thoracoscope.

Results

The targeted segment was uniformly visualized by indocyanine green fluorescence in 16/20 (80.0%) cases after insufflating indocyanine green. A receiver operating characteristic curve indicated that the area under the curve was 0.984; the optimal cut-off volume of diluted indocyanine green for insufflation was 8.91% of the calculated targeted pulmonary segment volume.

Conclusions

The setting for indocyanine green insufflation was optimized for near-infrared fluorescence image-guided anatomical segmentectomy. By injecting the correct amount of indocyanine green, fluorescence-guided anatomical segmentation may be performed more appropriately.

Construction of a computational mechanical model of bronchi for practical simulation of the optimal positive intrathoracic pressure conditions during general thoracic surgery

BACKGROUND

Thoracic CO2 insufflation with positive intrathoracic pressure is usually effective during thoracoscopic surgery, however, lung collapse is sometimes insufficient. We hypothesized that inappropriate bronchial collapse might cause this unsuccessful lung collapse.

OBJECTIVE

The objective of this study was to construct a computational mechanical model of bronchi for practical simulation to discover the optimal conditions of positive intrathoracic pressure during thoracoscopic surgery.

METHODS

Micro-focus high-resolution X-ray computed tomography measurements of lungs from just-slaughtered swine were extracted, and the three-dimensional geometries of the bronchi under pressurized and depressurized conditions were measured accurately. The mechanical properties of the bronchus were also measured. Computational fluid dynamics (CFD) and computational structural mechanics (CSM) analyses were conducted.

RESULTS

The CSM results indicated that the present structural model could simulate bronchial occlusion. The CFD results showed that airflows from pressed lung alveoli might cause low-internal-pressure regions when suddenly or heterogeneously pushed airflow was injected from a small branching bronchus to a large bronchus. A preliminary computational mechanical model of bronchi was constructed.

CONCLUSIONS

We demonstrated the performance of the mechanical model of bronchi in rough simulations of bronchial occlusions. However, this model should be verified further using human data to facilitate its introduction to clinical use.

Review of Approaches to Developing Intersegmental Plane during Segmentectomy

In recent years, with the popularity of computed tomography (CT) scanning, early lung cancer has been found in a large number of patients, and segmentectomy has been widely used in clinical practice. The development of intersegmental plane is the most critical step in segmentectomy. At present, there are many methods to identify the intersegmental plane. Also, dissection of the intersegmental plane has been a challenge for thoracic surgeons for decades because of the complicated anatomic variations. This study focuses on the safety and efficacy of relevant methods in both identification and dissection of the intersegmental plane in segmentectomy.

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.

Watershed analysis of the target pulmonary artery for real-time localization of non-palpable pulmonary nodules

Background

Some pulmonary nodules are not suitable for computed tomography-guided percutaneous localization. This study aimed to investigate the feasibility and safety of real-time localization for these non-palpable pulmonary nodules using watershed analysis of the target pulmonary artery during thoracoscopic wedge resection.

Methods

Watershed analysis is a novel technique that can be used to create a specific area on the lung surface for nodule localization. This analysis is performed by temporarily blocking the target pulmonary artery and using indocyanine green fluorescence during surgery. In our study, the surgery was simulated and evaluated preoperatively using a high-precision three-dimensional reconstruction model obtained by multidetector spiral computed tomography. The lung was observed using an infrared thoracoscopy system after an intravenous injection of indocyanine green (2.5 mg/mL), and the white-to-blue transitional zone was marked using electrocautery, after which a wedge resection was performed.

Results

A total of 25 out of 26 patients underwent successful wedge resection. The mean tumor size and depth based on computed tomography scans were 13.2±6.4 and 12.2±7.8 mm, respectively. The mean operation duration was 142.6±52.8 min. The mean bleeding volume during surgery was 12.9±9.7 mL. The mean drainage tube indwelling time was 35.6±20.0 h, and the median length of postoperative stay was 3 days (range, 2-6 days).

Conclusions

Our experience showed that the watershed analysis of the target pulmonary artery for nodule localization was safe and feasible. It may become an effective and attractive alternative method for localizing non-palpable pulmonary nodules in selected patients undergoing thoracoscopic wedge resection.

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.

No-waiting segmentectomy: an optimized approach for segmentectomy

Background

Currently, modified inflation–deflation is considered the easiest way to identify the intersegmental plane during pulmonary segmentectomy. However, this approach requires a wait of about 10–20 min during the operative procedure. Therefore, we optimized the procedure, which we call no-waiting segmentectomy. In this study, we compared no-waiting segmentectomy with the modified inflation–deflation method.

Methods

We studied 123 consecutive patients with pulmonary ground-glass nodules who underwent segmentectomy by uniportal video-assisted thoracoscopic surgery in a single medical group from January 2019 to April 2020. Forty-five patients underwent the modified inflation–deflation method and 78 patients underwent the no-waiting method. The no-waiting procedure involved severing of the target segmental pulmonary artery, inflating the lung with atmospheric air, dissecting the hilum, and dividing the target segmental bronchus. The entire procedure could be performed at a stretch and no pause was needed. We compared the two methods for surgery time, bleeding volume, drainage time, and postoperative hospital stay. Propensity-score matching was used to adjust the baseline characteristics.

Results

Thirty-three pairs of 123 patients were successfully matched. Before propensity-score matching, there was no difference between the two methods in terms of surgery time, bleeding volume, drainage time, and postoperative hospital stay. After propensity-score matching, the surgery time in the no-waiting group was significantly shorter than that in the modified inflation–deflation method group (80.12±35.53 vs. 102.97±48.07 min, P=0.03). There was no difference between the two methods in terms of bleeding volume, drainage time, and postoperative hospital stay.

Conclusions

No-waiting segmentectomy was associated with a reduced surgery time, compared to that associated with modified inflation–deflation segmentectomy. Furthermore, no-waiting segmentectomy did not increase bleeding volume, drainage time, and postoperative hospital stay. Thus, no-waiting segmentectomy is an optional optimized approach for segmentectomy.

Thoracoscopic Pulmonary Segmentectomy With Collateral Ventilation Method

BACKGROUND

Despite its popularity in recent years, segmentectomy still faces a challenge: the accurate delineation of the intersegmental plane, especially in complex segmentectomy. In this study, we describe a method using collateral ventilation to create an inflation-deflation line for video-assisted thoracoscopic surgery (VATS) segmentectomy and evaluated its efficacy in complex segmentectomy by comparing it with simple segmentectomy.

METHODS

Enrolled in the study were 264 patients who underwent VATS segmentectomy from January 2017 to September 2018. We classified the clarity of the inflation-deflation line into 4 grades, and the procedures of grade 3 or 4 were considered successful. Meanwhile, we performed a propensity score matching analysis to compare complex and simple segmentectomy.

RESULTS

Complete resection with free margins was achieved in all patients. In inflation-deflation line clarity evaluation, 245 patients were classified as grade 4 (92.8%), 10 as grade 3 (3.8%), 8 as grade 2 (3.0%), and 1 as grade 1 (0.4%). Procedural success (grade 3 or 4) was achieved in 255 patients (96.6%). Prolonged air leak (>5 days) was observed in 11 patients (4.2%). Propensity matching generated 83 pairs of well-matched patients. The proportion of procedural success and the incidence of prolonged air leak (>5 days) were similar in both groups. However, compared with simple segmentectomy, complex segmentectomy was associated with a longer median operative time (159 versus 135 minutes; P < .001).

CONCLUSIONS

Collateral ventilation method is simple, safe, and effective in VATS segmentectomy to identify the intersegmental plane, and also well-adapted for complex segmentectomy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognosis of segmentectomy in the treatment of stage IA non-small cell lung cancer

With improvements in detection technology, increasing numbers of patients with non-small cell lung cancer (NSCLC) are being diagnosed at an early stage. In order to treat the illness with minimal invasion and preserve lung function to the greatest possible extent, there has been an increasing tendency towards treating early-stage NSCLC by segmentectomy. However, questions remain regarding whether patients may benefit from this procedure considering the surgical and oncological outcomes. Whether adequate margin distance and lymph node dissection may be achieved is one of the most important issues associated with this procedure. The present study reviews the prognosis of segmentectomy in the treatment of stage IA NSCLC.

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

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

[Advances in Identification of Intersegmental Plane during Pulmonary Segmentectomy]

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Objectives

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

Methods

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

Results

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

Conclusions

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