Effect of cutting technique at the intersegmental plane during segmentectomy on expansion of the preserved segment: comparison between staplers and scissors in ex vivo pig lung

Compensatory expansion of the right middle lobe: volumetric and functional analysis of the changes after right upper or lower lobectomy

The right middle lobe often poorly expands after right upper lobectomy. Postoperative pulmonary function may be inferior after right upper lobectomy than after right lower lobectomy due to poor expansion of the middle lobe. This study examined the difference in the postoperative right middle lobe expansion and pulmonary function between right upper and right lower lobectomy. Patients who underwent right upper or right lower lobectomy through video-assisted thoracic surgery (n = 82) were enrolled in this retrospective study. Pulmonary function tests and computed tomography were performed preoperatively and at 1 year postoperatively. Using three-dimensional computed tomography volumetry, the preoperative and postoperative lung volumes were measured, and the predicted postoperative forced expiratory volume in 1 s was calculated. Middle lobe volume ratio (i.e., ratio of the postoperative to the preoperative middle lobe volume) and the postoperative forced expiratory volume in 1 s ratio (i.e., ratio of the measured to the predicted postoperative forced expiratory volume in 1 s) were compared between right upper and right lower lobectomy. Compared with the patients who underwent right upper lobectomy (n = 50), those who underwent right lower lobectomy (n = 32) had significantly higher middle lobe volume ratio (1.15 ± 0.32 vs. 1.63 ± 0.52, p < 0.001) and postoperative forced expiratory volume in 1 s ratio (1.12 ± 0.12 vs. 1.19 ± 0.13, p = 0.010). The right middle lobe showed more expansion and better recovery of postoperative pulmonary function after right lower lobectomy than after right upper lobectomy.

Three-dimensional imaging anatomical research and clinical implications of V1 +2 d in the left upper lung

BACKGROUND

To investigate the distribution pattern of V1+2 d in the left superior pulmonary vein and its clinical significance.

METHODS

A retrospective analysis was conducted using three-dimensional computed tomographic bronchography and angiography (3D-CTBA) data from 500 lung cancer patients. Statistical analyses were performed to evaluate the incidence and drainage patterns of the three sub-branches of V1+2 d, namely V1+2 d1, V1+2 d2 and V1+2 d3. Furthermore, clinical data from 10 patients' lesions involving V1+2 d were reviewed to illustrate the impact of adjacency to V1+2 d on the surgical approach.

RESULTS

The incidences of V1+2 d1, V1+2 d2 and V1+2 d3 were 100%, 76.4% and 100% respectively. The relative interlobar distribution sizes of B3 a and B1+2 c and the left upper division (LUD) vein type influenced the incidence of V1+2 d2 (p < 0.05; p < 0.001). V1+2 d2 predominantly occurred in B3 a = B1+2 c and B1+2 c > B3 a patterns. V1+2 d2 was entirely absent in the B3 a > B1+2 c pattern. V1+2 d2 exhibited a higher incidence in both the central vein (CV) type and the noncentral vein (NCV) type when compared to the semi-central vein (SCV) type (100% vs. 100% vs. 64.8%). The most prevalent venous drainage pattern was the three sub-branches of V1+2 d constituting a major trunk to drain (41.2%). All 10 cases with lesions involving V1+2 d successfully underwent sublobar resection with no complications, and the surgical margin was ≥2 cm.

CONCLUSIONS

The three sub-branches of V1+2 d exhibit a high incidence with diverse distribution patterns, yet a discernible pattern exists. For inter- or multi-intersegmental nodules involving V1+2 d, combined segmentectomy and subsegmentectomy or combined subsegmentectomy can ensure the safe margin.

Pulmonary function changes after sublobar resection in patients with peripheral non-subpleural nodules

Background

In the treatment of peripheral early-staged lung cancer and benign lesions, segmentectomy and wedge resection are both reliable treatment methods. It is debatable that how much pulmonary function will be lost after different sublobar resection in the treatment of early-staged deep-located peripheral NSCLC (non-small cell lung cancer). The purpose of this study was to explore postoperative pulmonary function changes of sublobar resection in enrolled patients with non-subpleural peripheral nodules.

Methods

We collected clinical data of patients undergoing VATS (video-assisted thoracoscopic surgery) segmentectomy or wedge resection for single nodule. These nodules were confirmed as peripheral non-subpleural nodules by preoperative 3D imaging. Patients were divided into two groups according to the operation procedure. Demographic characteristics, pulmonary function, postoperative outcomes, and others were collected. All data was gathered at the First Affiliated Hospital of Soochow University. Outcomes after wedge resection were compared with those after segmentectomy resection.

Results

A total of 88 patients were included in this study, including 46 patients with VATS wedge resection and 42 patients with VATS segmentectomy. No difference was detected when comparing FEV1 (forced expiratory volume in 1 s) loss between these two groups (17.6 ± 2.1%, wedge resection vs. 19.4 ± 5.4%, segmentectomy, P = 0.176). FVC (forced vital capacity) loss (8.7 ± 2.3%, wedge resection vs. 17.1 ± 2.2%, segmentectomy, P < 0.001) and MVV (maximum ventilatory volume) loss (11.5 ± 3.1%, wedge resection vs. 20.6 ± 7.8%, segmentectomy, P < 0.001) in segmentectomy group was significantly higher than those in wedge resection group. Discrepancies were investigated when comparing duration of surgery (70 ± 22 min, wedge resection vs. 111 ± 52 min, segmentectomy, P = 0.0002), postoperative drainage (85 ± 45 mL, wedge resection vs. 287 ± 672 mL, segmentectomy, P = 0.0123), and treatment hospitalization expenses [35148 ± 889CNY, wedge resection vs. 52,502 (38,276–57,772) CNY, segmentectomy, P < 0.0002]. No significant difference was found between air leak time (1.7 ± 0.7 days, wedge resection vs. 2.5 ± 1.7 days, segmentectomy, P = 0.062) and hospitalization time (2.7 ± 0.7 days, wedge resection vs. 3.5 ± 1.7 days, segmentectomy, P = 0.051).

Conclusions

For patients with peripheral non-subpleural nodules, we observed that patients who underwent wedge resection had less lung function loss than those who underwent segmentectomy when their lung function was reviewed at the 6th month after surgery. Patients undergoing wedge resection had partial advantages over patients with segmental resection in terms of hospitalization cost, operation time and postoperative drainage, etc. Wedge resection, as a treatment for peripheral non-subpleural pulmonary nodules, seemed to have more advantages in preserving patients’ pulmonary function.

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.

Double stapling method for closure of intraoperative alveolar air leakage adjacent to the staple line: a randomized experimental study on ex vivo porcine lungs

Background

Alveolar air leakage from a pleural defect around the staple line is one of the complications after wedge resection of the lung. An intraoperative closure of the pleural defect by suturing can cause additional pleural rupture due to tension of the pleura adjacent to staple lines. Therefore, we have introduced a novel closure method for pleural defect adjacent to the staple line, named the double stapling method. This study compared the efficacy of two closure methods; the double stapling method and conventional suturing method with pledgets using ex vivo porcine lungs.

Methods

The double stapling method involves closing the pleural defect by suturing the two parallel staple lines at both sides of the pleural defect. This method was developed to distribute the pleural tension around the needle holes of suturing. As a model of pleural defect adjacent to the staple line after wedge resection, wedge resection of the caudal lobe of left porcine lungs was performed, and a superficial square pleural defect (10 mm × 10 mm) adjacent to the staple line was made by scalpel. The defect was closed using the following two methods: (I) suturing with pledgets (n=10); and (II) double stapling method (n=10). The lobe was inflated in water at an airway pressure of 20, 25, and 30 cmH₂O; closure success or failure was judged by the absence or presence of air leakage.

Results

The closure success was confirmed in 2 (20%) out of 10 cases in the suturing with pledgets group and 9 (90%) out of 10 in the double stapling method group (P=0.007). In 4 out of 10 cases in the suturing with pledgets group, new pleural clefts longer than 3 mm were created around the needle holes of suturing.

Conclusions

Ex vivo experiments have suggested the superiority of the double stapling method for the intraoperative closure of alveolar air leakage adjacent to the staple line after wedge resection, compared to conventional suturing with the pledget method.

Advances and safe use of energy devices in lung cancer surgery

Objectives

A clear understanding of energy devices would help achieve high effectiveness and safety and guide the selection of devices. The present review aimed to elucidate the efficacy and adverse events of energy devices in lung cancer to guide the selection of appropriate devices depending on the situation.

Methods

Four major databases were searched electronically for relevant articles published until 16 April 2021. The reference lists of the identified papers were examined. We excluded (1) irrelevant studies, (2) manuscripts published in languages other than English and Japanese, (3) duplicates, and (4) studies for which the full text was not available in the databases. The results and key information obtained were summarized by means of a narrative approach.

Results

A total of 78 papers were included in the review and these were categorized according to the main topic of investigation as follows: (1) electrosurgery-related injuries, (2) fundamentals of electrosurgery, (3) monopolar devices, (4) bipolar electrosurgical devices, (5) ultrasonic energy devices, (6) energy devices in lung cancer surgery, (7) operating room fire risks, and (8) basic principles of surgery.

Conclusions

Understanding energy devices could help us use them in a more effective and safer manner. Knowledge of their selection criteria (suitability), merits, risks, and safety precautions relevant to each process of lung cancer surgery could guide appropriate selection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11748-022-01775-w.

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.

Changes in Forced Expiratory Volume in 1 Second after Anatomical Lung Resection according to the Number of Segments

Background

Although various methods are already used to calculate predicted postoperative forced expiratory volume in 1 second (FEV₁) based on preoperative FEV₁ in lung surgery, the predicted postoperative FEV₁ is not always the same as the actual postoperative FEV₁. Observed postoperative FEV₁ values are usually the same or higher than the predicted postoperative FEV₁. To overcome this issue, we investigated the relationship between the number of resected lung segments and the discordance of preoperative and postoperative FEV₁ values.

Methods

From September 2014 to May 2020, the data of all patients who underwent anatomical lung resection by video-assisted thoracoscopic surgery (VATS) were gathered and analyzed retrospectively. We investigated the association between the number of resected segments and the differential FEV₁ (a measure of the discrepancy between the predicted and observed postoperative FEV₁) using the t-test and linear regression.

Results

Information on 238 patients who underwent VATS anatomical lung resection at Kyung Hee University Hospital at Gangdong and by DH. Kim for benign and malignant disease was collected. After applying the exclusion criteria, 114 patients were included in the final analysis. In the multiple linear regression model, the number of resected segments showed a positive correlation with the differential FEV₁ (Pearson r=0.384, p<0.001). After adjusting for multiple covariates, the differential FEV₁ increased by 0.048 (95% confidence interval, 0.023–0.073) with an increasing number of resected lung segments (R²=0.271, p<0.001).

Conclusion

In this study, after pulmonary resection, the number of resected segments showed a positive correlation with the differential FEV₁.

"Non-Triangle Plane" Surgical Technique of Video-Assisted Thoracic Surgery Atypical Segmentectomy for Stage IA Non-Small-Cell Lung Cancer: Early Experience

Objectives: To evaluate the safety and feasibility of a novel surgical technique (“non-triangle plane” technique) of two-port (mini-utility) video-assisted thoracic surgery (VATS) atypical segmentectomy (S³+S¹⁺²c) with tunneling stapler for small-sized non-small-cell lung cancers (NSCLCs) located in left S³ close to the intersegmental plane between S³ and S¹⁺²c.

Materials and Methods: This retrospective descriptive study included 16 patients who, between April 2016 and December 2019, underwent a single two-port (mini-utility) VATS atypical segmentectomy (S³+S¹⁺²c) with tunneling stapler technique for small-sized NSCLCs with a ground-glass opacity (GGO) rate of more than 50% by a constant surgical team in two hospitals. Perioperative data and survival data were collected and retrospectively analyzed. Postoperative follow-up was performed every 6 months.

Results: Six patients were with adenocarcinoma in situ, and ten were with minimally invasive adenocarcinoma. The mean surgical margin was 14.06 ± 3.02 mm. The mean operation time was 53.88 ± 9.76 min. The mean duration of chest tube drainage was 4 ± 1.21 days, and the median length of postoperative hospital stay was 4 days. There was no perioperative morbidity and mortality. The median follow-up was 47.5 months (17–61 months). No recurrences occurred, and all patients were still alive at the last registered follow-up (May 31, 2021).

Conclusion: Two-port (mini-utility) VATS atypical segmentectomy (S³+S¹⁺²c) with tunneling stapler technique is a safe and feasible option for the treatment of small-sized NSCLCs located in left S³ close to the intersegmental plane between S³ and S¹⁺²c.

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.

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.

Stapled video-assisted thoracoscopic segmentectomy preserves as much lung volume as nonstapled video-assisted thoracoscopic segmentectomy

BACKGROUND

Two different techniques of performing segmentectomy have been reported in the era of video-assisted thoracosopic surgery (VATS), including stapled segmentectomy (SS) and non-stapled segmentectomy (NSS). Some surgeons favor stapled segmentectomy for better pneumostatic control, while others prefer non-stapled segmentectomy to avoid compromising adjacent pulmonary parenchyma. In this study, we used multidetector computed tomography (MDCT) and spirometry to evaluate lung volume preservation of different segmentectomy techniques.

METHODS

A total of 269 patients undergoing video-assisted thoracic surgery (VATS) segmentectomy between October 2013 and September 2016 in a single institution were reviewed. Perioperative outcomes, the cost of hospital admission, the change in forced expiratory volume in 1 s (FEV1) (ΔFEV1 and ΔFEV1%), and residual ipsilateral volume ratios (RiVR) were compared.

RESULTS

The final study population consisted of 107 patients: 30 patients underwent NSS, and 77 patients underwent SS. The NSS group had significantly longer operative time, more blood loss, longer duration of chest tube placement and postoperative hospitalization than the SS group. The follow-up of RiVR (at 6 months, 12 months, 24 months), ΔFEV1(L), and ΔFEV1(%) demonstrated no significant difference between NSS and SS group.

CONCLUSION

Our study demonstrated that postoperative residual lung volume was not influenced by different segmentectomy techniques.

How to identify intersegmental planes in performing sublobar anatomical resections

Pulmonary segmentectomy is a common surgical procedure in thoracic surgery nowadays. Though this technique helps preventing postoperative pulmonary function loss, potential challenges are the management of air leaks and the difficulty of palpating ground-glass components during surgery, as well as how to deal with the intersegmental planes. Several techniques have been proposed for the identification and treatment of the intersegmental planes during sublobar anatomical resections: this review focuses on preoperative planning and workup and intraoperative strategies. Three-dimensional computed tomography bronchography and angiography (3D-CTBA), virtual-assisted mapping (VAL-MAP) using bronchoscopy multi-spot dye marking and three-dimensional computed tomography (3D-CT) are preoperative tools that may facilitate the planning of operation. Inflation-deflation techniques, infrared-fluorescence-enhanced method combined with bronchial and intravenous injection of indocyanine green (ICG) and near-infrared fluorescence (NIF) mapping with ICG have been described as intraoperative strategies to identify the intersegmental plane. The treatment and section of the intersegmental planes is mainly accomplished by stapler and electrocautery or energy devices. The use of staplers reduces postoperative air leaks, bleeding risks and operative time but seems to reduce preserved lung volume, compromising adjacent lung expansion; in addition, higher costs and sometimes non-adequate oncological margins, being a non-anatomical technique have been described. The electrocautery and energy devices allow for a more anatomical and precise dissection maintaining safe oncological margins, with a better lung expansion and so an increased postoperative lung function. Time consuming procedure and frequent requirement of aero-haemostatic tools to treat air and blood leaks are the main drawbacks. In conclusion, there are several methods to identify and treat the intersegmental planes but there are no significant differences between the different tools, therefore the use of one technique rather than another depends overall on surgeon's preference and the location of the segment.

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

Background

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

Methods

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

Result

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

Conclusions

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

Safety of a Novel Microwave Surgical Instrument for Lung Parenchyma Dissection During Segmentectomy

BACKGROUND

The choice between electrocautery or automatic suturing instruments for dissection of the lung parenchyma along the intersegmental plane during lung segmentectomy remains controversial. We hypothesized that a novel microwave surgical instrument (MSI) for dissecting the lung parenchyma could have excellent sealing effects. We examined the feasibility and safety of lung parenchymal dissection using a MSI during lung segmentectomy.

METHODS

This was a prospective clinical study of lung segmentectomy involving dissection of the entire intersegmental plane using a MSI. Complications related to sealing of the lung parenchyma were evaluated and perioperative outcomes were compared to those of patients who underwent lung segmentectomy using automatic suturing instruments. Propensity score-matched comparisons were used to assess the potential impact of selection bias.

RESULTS

Lung segmentectomy using a MSI was successfully performed in 30 patients. According to the propensity score matching analysis, intraoperative blood loss, length of hospital stay, and postoperative complications of the microwave group were significantly lesser (P = .019, .003, and .008, respectively) compared to those of the control group (n = 66). Prolonged air leakage was not observed. There were two cases of subcutaneous emphysema after removal of the chest tube, but no other grade 2 or higher complications were observed. No mortality occurred within 30 or 90 days postoperatively.

CONCLUSIONS

The use of a MSI for lung parenchymal dissection was associated with lower blood loss during surgical procedures, reduced air leakage after the operation, and fewer postoperative complications.

Early postoperative inflammatory response by procedure types: stapler-based segmentectomy versus lobectomy

OBJECTIVE

Perioperative C-reactive protein (CRP) levels have become a contentious topic on the surgical outcome of lung cancer, but the influence of the procedure types has not been precisely investigated. From this viewpoint, we compared two types of thoracoscopic anatomical lung resection: segmentectomy and lobectomy.

METHODS

This was a retrospective study involving patients who underwent standardized anatomical lung resection at a single institute from 2014 to 2017; CRP levels were routinely measured on postoperative days 1, 3, and 5. Changes in the CRP levels from the preoperative period were calculated (ΔCRP), and factors associated with a higher ΔCRP value were analyzed.

RESULTS

Among 186 patients included, 91 (48.9%) patients underwent stapler-based segmentectomy and 95 (51.1%) patients underwent lobectomy. The segmentectomy group showed significantly higher ΔCRP values on every measurement day than the lobectomy group, in spite of shorter operation time, smaller blood loss, shorter drainage periods, shorter dissection time, and limited lymph node dissection. The number of stapler cartridges for the lung parenchyma was significantly larger in the segmentectomy group. Regression analyses indicated that procedure type and smoking history were associated with a higher ΔCRP value, whereas no significant difference was indicated in the smoking history between the groups.

CONCLUSION

In our cohort, stapler-based thoracoscopic segmentectomy was associated with an increase in acute inflammatory response despite favorable perioperative outcome compared to lobectomy. Local surgical stress and damage in the remaining segments might play a key role and warrants further investigation.

[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。

Technique for tailoring complex demarcation in lung segmentectomy

Segmentectomy is a widely adopted surgical procedure, however, experiences of tailoring the intersegmental border have rarely been reported. This paper investigates the strategy and results of tailoring complex demarcation during lung segmentectomy surgery. Because intersegmental demarcation can be divided into plane or curved types according to the location and stereo shape of a segment, a one‐size‐fits‐all method for tailoring the intersegmental demarcation is obviously unreasonable. For tailoring a complex segmentectomy with two or more curved borders, tips including good exposure of the intersegmental demarcation, sharp‐blunt combined dissection skill, “work‐plane” extension, and “gate” opening techniques all contribute to an accurate segmentectomy. This technique, based on anatomical characteristics, can provide a cutting surface with a greater physiological shape and less curling of the edge, and should be recommended as a general standard method for tailoring complex demarcation.

Influence of intersegmental plane size and segment division methods on preserved lung volume and function after pulmonary segmentectomy

OBJECTIVES

We previously reported that the use of a stapler to divide intersegmental planes did not decrease preserved pulmonary volume or function relative to electrocautery. However, preservation of pulmonary volume or function can be compromised when a stapler is used with larger intersegmental planes. Here, we assessed the correlations between preserved lung volume and pulmonary function after segmentectomy and the size of the intersegmental planes, based on the division method.

METHODS

Intersegmental plane sizes in 56 patients were semi-automatically calculated using image analysis software on computed tomography images. The ratios of the remnant segment and ipsilateral lung volumes to their preoperative values (R-seg and R-ips) and the ratio of the postoperative pulmonary function relative to the predicted value were calculated based on three-dimensional volumetry. Correlations between preserved lung volume and pulmonary function and the intersegmental plane sizes were analyzed according to the division method.

RESULTS

Intersegmental planes were divided by either electrocautery or with a stapler (EC/Mixed) in 21 patients and by stapler alone (ST) in 35 patients. There was no difference in the average size of the intersegmental planes between the two groups. The intersegmental plane size negatively correlated with R-seg in the ST group.

CONCLUSIONS

Using the stapler method, as the size of the intersegmental planes increased, the preserved remnant segmental volume decreased; however, relation between the plane size and preserved pulmonary function was unclear. These findings indicate that stapler use is acceptable even for large intersegmental planes.

Division of the intersegmental plane using electrocautery for segmentectomy in clinical stage I non-small cell lung cancer

Background

Division of intersegmental planes is one of the important practical issues for segmentectomy to obtain feasible outcomes without relapse for clinical stage I non-small cell lung cancer. Almost all surgeons perform this procedure using a stapler. However, division of intersegmental planes for segmentectomy can also be performed by electrocautery. In this article, we demonstrate the merits and drawbacks of division of the intersegmental plane by electrocautery for segmentectomy.

Methods

Of those 125 patients who underwent segmentectomy with clinical stage I primary lung cancer, we compared cautery cases (n=50) with stapler cases (n=75). The cautery group included 29 cases (58.0%) with partial use of a staple at the end of division.

Results

Operative time was significantly longer in cautery cases (281±72 min) than stapler in cases (235±86 min; P=0.003). No difference in the duration of chest tube placement was evident between cautery (3.0±3.0 days) and stapler groups (2.8±1.7 days; P=0.613). However, delayed air leakage occurred significantly more frequently in cautery cases (14.0%) than in stapler cases (4.0%; P=0.048). Five-year overall survival (OS) in clinical stage I was 94.7% in cautery cases and 80.5% in stapler cases (log-rank P=0.047). Five-year disease-free survival (DFS) was 80.0% and 71.3%, respectively (log-rank P=0.075).

Conclusions

The merits of cautery division include the ability to achieve meticulous division of the intersegmental plane and good preservation of the shape of residual segments. Conversely, the drawbacks include prolonged air leakage. Pleural suture or closure of residual segments may be useful to prevent delayed air leakage.

Pulmonary function changes after different extent of pulmonary resection under video-assisted thoracic surgery

Background

Limited resections for early stage lung cancer have been of increasing interests recently. However, it is still unclear to what extent a limited resection could preserve pulmonary function comparing to standard lobectomy, especially in the context of minimally invasive surgery. The purpose of this study was to evaluate postoperative changes of spirometry in patients undergoing video-assisted thoracic surgery (VATS) lobectomy or limited resections.

Methods

Spirometry tests were obtained prospectively before and 6 months after 75 VATS lobectomy, 34 VATS segmentectomy, 15 VATS wedge resection. Eleven VATS mediastinal procedures without lung resection were taken as a control group. Results were compared between groups of different resection extent.

Results

Demographic characteristics and preoperative pulmonary function showed no differences among the four groups. Forced vital capacity (FVC) loss after lobectomy was significantly greater than after segmentectomy (P=0.048), and much significantly greater than after wedge resection (P<0.001). Forced expiratory volume in 1 second (FEV1) loss after lobectomy was similar to segmentectomy (P=0.273), both significantly greater than after wedge resection (P<0.01). Diffusing capacity of the lungs for carbon monoxide (DLCO) loss was similar among these three groups (P=0.293). There was no significant difference in any spirometry index between wedge resection and mediastinal procedures (FVC: P=0.856; FEV1: P=0.671; DLCO: P=0.057). When compared by average value per segment resected, pulmonary function loss was significantly less after lobectomy than after segmentectomy in all spirometry indexes (P<0.001). On average, pulmonary function loss was around 5% per segment for VATS lobectomy and 10% per segment for VATS segmentectomy.

Conclusions

In minimal invasive surgery, wedge resection best preserves pulmonary function with similar spirometry change with VATS mediastinal procedures without lung resection. Compared with VATS lobectomy, VATS segmentectomy may help minimize loss of FVC but not FEV1 or DLCO. Pulmonary function loss per segment resected is doubled after VATS segmentectomy than after lobectomy. These results should be taken into account when deciding the extent of resection for patients with early stage lung cancer.

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.

Swine model for training surgeons in minimally invasive anatomic lung segmentectomy

BACKGROUND

Despite the increasing demand for thoracoscopic lung segmentectomy, the appropriate training method is not well established. Therefore, we developed a swine model for anatomical thoracoscopic lung segmentectomy training.

METHODS

Three-month-old pigs, weighing 40 to 45 kg, were used in this model. Anterior segmentectomy of the left cranial lobe and segmentectomy of the most anterior left caudal lobe were performed under general anesthesia and differential ventilation. Participants from several institutions participated in this program, which included training lectures and surgical skill drills.

RESULTS

From 2010 to 2015, 33 pigs were used for the lung segmentectomy training with 51 trainees. Eight pigs were operated on using the hybrid approach, and 25 pigs were operated on using the complete thoracoscopic approach. Among 25 pigs in which the complete thoracoscopic approach was used, conversion to thoracotomy was required in 3 pigs, owing to hemorrhage in two and failure of differential ventilation in one. The no-touch method in supine position provided sufficient intersegmental delineation of 20 (76%) planes among 26 left anterior segmentectomies in the cranial lobe.

CONCLUSIONS

Our live swine model of anatomical thoracoscopic lung segmentectomy is considered a good choice for training surgeons on how to perform minimally invasive lung segmentectomy in humans.

[Electrocautery versus Stapler for Intersegmental Plane Dissection in Complete Thoracoscopic Segmentectomy]

BACKGROUND

Complete thoracoscopic segmentectomy gained great attention with the high detection rate of early lung cancer. Electrocautery and stapler are most commonly used in dividing the intersegmental plane in pulmonary segmentectomy. However, few reports comparing the two methods exist; all of which contrapose an open approach because complete thoracoscopic approach is not mentioned. The aim of this study is to evaluate and compare the safety and efficacy of the two methods in intersegmental plane dissection during complete thoracoscopic pulmonary segmentectomy.

METHODS

A retrospective review of prospectively collected data was obtained for 58 consecutive patients who were treated by segmentectomy between September 2013 and March 2016 at a single center. The patients were divided into two groups according to the methods in intersegmental plane dissection. Thirty patients underwent intersegmental plane dissection with electrocautery (electrocautery group), and 28 patients underwent the same process using staplers (stapler group). Preoperative, intraoperative, and postoperative variables for patients were compared between two groups.

RESULTS

The operative time of electrocautery group was longer than that of the stapler group [(248.70±54.46) min vs (209.39±67.25) min, P=0.017]. Furthermore, no statistical difference was found between two groups in intraoperative blood loss (60.00 mL vs 65.00 mL), total drainage volume (445.00 mL vs 590.00 mL), drainage volume in first 3 days after surgery [(455.33±318.333) mL vs (422.32±194.95) mL], duration of chest tube drainage [(4.20±2.07) d vs (4.11±1.61) d], postoperative hospital stay [(6.33±2.98) d vs (5.89±1.55) d], and incidence of minor postoperative complication [16.7% (5/30) vs 7.1% (2/28)].

CONCLUSIONS

Although operative time was longer in electrocautery group than in stapler group, using electrocautery for intersegmental plane dissection in complete thoracoscopic segmentectomy appeared to be a very safe and feasible procedure compared with stapler.

Management of Intersegmental Plane on Pulmonary Segmentectomy Concerning Postoperative Complications

BACKGROUND

For primary lung cancer, anatomic pulmonary segmentectomy may have a functional advantage over lobectomy; however, persistent air leak or delayed pneumothorax after segmentectomy is prevalent and increases surgical morbidity. To prevent pulmonary complications after pulmonary segmentectomy, we used 2 methods for the involved intersegmental plane: coverage using polyglycolic acid mesh and fibrin glue (mesh cover) or closing it by suturing the pleural edge (pleural suture). We aimed to compare postoperative pulmonary function and complications between the 2 groups.

METHODS

A total of 133 patients who underwent pulmonary segmentectomy for stage IA non-small cell lung cancer were analyzed retrospectively. A pulmonary function test, including vital capacity and forced expiratory volume in 1 second, was performed preoperatively and at 1 and 6 months postoperatively. Propensity score analysis generated 2 matched pairs of 46 patients in the pleural suture and mesh cover groups.

RESULTS

In each group, there was no significant difference in the recovery rate of vital capacity and forced expiratory volume in 1 second at 1 and 6 months postoperatively. Compared with the pleural suture group, the mesh cover group had higher incidence of prolonged air leak (8.7% versus 0%; p = 0.042), delayed pneumothorax (10.9% versus 2.2%; p = 0.051). On logistic regression analysis, management of intersegmental plane by either mesh cover or pleural suture was the only independent factor related to pulmonary complications (prolonged air leak or delayed pneumothorax) after pulmonary segmentectomy (odds ratio: 5.26, p = 0.047; odds ratio: 13.39, p = 0.018, respectively).

CONCLUSIONS

Pleural suturing of the involved intersegmental plane during pulmonary segmentectomy appeared to be an acceptable method to reduce postoperative pulmonary complications.

Division of the intersegmental plane during thoracoscopic segmentectomy: is stapling an issue?

BACKGROUND

Stapling is becoming the method of choice for dividing the intersegmental plane during thoracoscopic segmentectomies. The technique however is controversial as it can impair re-expansion of preserved segments. We have analyzed the morbidity and lung re-expansion on a series of 175 thoracoscopic segmentectomies.

METHODS

A total of 175 patients underwent a thoracoscopic anatomic segmentectomy. Ten patients were excluded due to conversion into thoracotomy. There were 89 females (54%) and 76 males (46%). Mean age was 63 years (range, 18-83 years). Indications for segmentectomy were as follows: primary lung cancer (n=100, 61%), metastases (n=27, 16%), benign non-infectious lesions (n=20, 12%) and benign infectious lesions (n=18, 11%). The intersegmental plane was divided with an endostapler in all patients. Lung re-expansion assessment included chest roentgenograms at discharge and at one-month consultation.

RESULTS

The overall complication rate was 17%. There were 0.6% major complications and 16% minor complications. The average duration of drainage was 3 days (range, 1-13 days) and average length of stay was 5.7 days (range, 2-22 days). At discharge and at 1-month follow-up chest radiography, incomplete lung re-expansion was observed in 12 (7.4%) and 4 patients (2.8%) respectively. Patients who underwent upper lobe segmentectomy had significantly more incomplete re-expansion at discharge and at 1-month follow-up. On univariate analysis, mean drainage duration was significantly longer in patients who underwent upper segmentectomy (mean 3.7 days; range, 1-13) than those who underwent lower segmentectomy (mean 2.7 days; range, 1-5).

CONCLUSIONS

Although stapling of the intersegmental plane most likely slightly impairs lung re-expansion, clinical and radiological consequences are minimal.

A case of pulmonary granuloma associated with mycobacterium avium complex infection arising from the surgical margin after segmentectomy

The patient was a 50-year-old man with a history of right S9 + 10 segmentectomy for lung carcinoid at another hospital 4 years and 9 months ago. Two years and nine months after the surgery, a nodule was noted at the surgical margin. Furthermore, 9 months later, the nodule was enlarged and detected a strong accumulation on positron emission tomography-computed tomography. Therefore, the recurrence could not be denied and surgery was performed. The intraoperative pathological diagnosis was inflammatory granuloma, which was then removed by wedge resection. A culture of the tumor content showed mycobacterium avium complex (MAC). The final pathological diagnosis was a pulmonary inflammatory granuloma associated with MAC infection. Although a number of studies showed the risk of foreign body granuloma or an inflammatory pseudotumor after pulmonary resection with surgical staples, in this case the prior segmentectomy was carried out with electrical cautery alone. A nodule detected at the surgical margin after segmentectomy should be suspected to be an inflammatory change, in particular granuloma formation, as well as tumor recurrence and second primary lung cancer, even if the segmentectomy was done without staplers.

Triple-layer sealing with absorptive mesh and fibrin glue is effective in preventing air leakage after segmentectomy: results from experiments and clinical study

OBJECTIVES

Fibrin glue in combination with polyglycolic acid (PGA) mesh is effective in preventing air leakage after segmentectomy, but we frequently experienced air leakage with single-layer application. To investigate improved usage, we compared the sealing effect among single-, double- and triple-layer PGA mesh and fibrin glue in both experimental and clinical segmentectomy.

METHODS

Ex vivo pig lungs were used for experiments. As a model of segmentectomy, the lateral segment of the left lung was removed using electrocautery. As a model of peripheral lung defect, peripheral lung tissue was resected with scissors. The inter-segmental plane and the peripheral lung defect were sealed using one of the following four methods: (i) fibrin glue alone (Group 1, n = 8), (ii) single-layer with PGA mesh and fibrin glue (Group 2, n = 8), (iii) double-layer (Group 3, n = 8) and (iv) triple-layer (Group 4, n = 8). The seal-breaking pressures among them were compared. In clinical segmentectomy, the periods of chest-tube drainage were compared retrospectively between 17 patients treated by the single-layer and 17 treated by the triple-layer method.

RESULTS

In experimental segmentectomy, the seal-breaking pressure in the triple-layer (100 ± 25 cmH2O) was significantly higher than those in the other methods (26 ± 17, 48 ± 12 and 69 ± 19 cmH2O in the Groups 1, 2 and 3, respectively, P < 0.001-0.05), while there were no significant differences among other methods. For peripheral lung defect, the seal-breaking pressures did not differ among the methods. In clinical segmentectomy, the mean chest-drainage period with the triple-layer was 2 ± 0.9 days, which was significantly shorter than 3.6 ± 2.8 days with the single-layer (P = 0.009).

CONCLUSIONS

Stronger sealants are required to prevent air leakage from inter-segmental planes than from peripheral lung. To prevent air leakage after segmentectomy, triple-layer PGA mesh and fibrin glue is recommended.

Dissection of lung parenchyma using electrocautery is a safe and acceptable method for anatomical sublobar resection

BACKGROUND

Anatomic sublobar resection is being assessed as a substitute to lobectomy for primary lung cancers. However, persistent air leak after anatomic sublobar resection is prevalent and increasing surgical morbidity and costs. The use of electrocautery is being popularized recently in anatomic sublobar resection. We have retrospectively evaluated the safety and efficacy of intersegmental plane dissection using electrocautery.

METHODS

Between April 2009 to September 2010, 47 patients were treated with segmentectomy for clinical T1N0M0 non-small cell lung cancers. The intersegmental plane was dissected using electrocautery alone or in combination with staplers. We evaluated the methods of dividing intersegmental plane (electrocautery alone or combination with electrocautery and staplers), intraoperative blood loss, duration of chest tube placement, duration of surgery, preoperative FEV1.0%, incidence of prolonged air leak, length of postoperative hospital stay, postoperative pulmonary function at 6 months after surgery and the cost for sealing intersegmental plane.

RESULTS

Among the 47 patients, 22 patients underwent intersegmental plane dissection with electrocautery alone and 25 patients did in combination with electrocautery and staplers. The mean number of stapler cartridges used was only 1.3 in electrocautery and staplers group. Mean age, gender, number of patients whose FEV1% < 70% were similar between two groups. There was no statistical difference between electrocautery alone and combination with electrocautery and staplers group in duration of surgery (282 vs. 290 minutes), intraoperative blood loss (203 vs.151 ml), duration of chest tube placement (3.2 vs. 3.1 days), postoperative hospital stay (11.0 vs.10.0 days), postoperative loss of FEV1.0 (13 vs.8 %), loss of FVC (11 vs. 6 %) or incidence of minor postoperative complications [9 % (2/22) vs. 16 % (4/25), p = 0.30)]. However, incidence of prolonged air leak was higher in electrocautery alone group than in combination with electrocautery and staplers group [14 % (3/22) vs. 4 % (1/25), p = 0.025)]. The cost of materials for sealing air leaks amounted to €964 per patient in the electrocautery alone group and €1594 per patient in combination with electrocautery and staplers group.

CONCLUSIONS

The number of patients with prolonged air leak was higher in the electrocautery alone group. The use of staplers in addition to electrocautery may lead to reduced prolonged air leak. However, the use of electrocautery for intersegmental plane dissection appeared to be safe with acceptable postoperative complications and effective in reducing costs.