Quantification of the impact of segmentectomy on pulmonary function by perfusion single-photon-emission computed tomography and multidetector computed tomography

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.

Differential efficacy of segmentectomy and wedge resection in sublobar resection compared to lobectomy for solid-dominant stage IA lung cancer: a systematic review and meta-analysis

BACKGROUND

Currently, the impact of sublobar resection versus lobectomy on the prognosis of solid-dominant stage IA lung cancer is contradictory in different studies, which requires further exploration.

METHODS

The authors analyzed 26 studies, including one randomized controlled trial and retrospective cohort studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models based on heterogeneity levels.

RESULTS

The analysis included 12 667 patients, with 3488 undergoing sublobar resections and 9179 receiving lobectomies. The overall analysis revealed no statistically significant difference in overall survival (OS) (HR=1.28, 95% CI: 0.98-1.69) between sublobar resection and lobectomy, but lobectomy was associated with better recurrence-free survival (RFS) (HR=1.39, 95% CI: 1.10-1.75). Subgroup analyses revealed that, for tumors with a diameter ≤2 cm, sublobar resection versus lobectomy showed no significant difference in OS but sublobar resection had lower RFS. For 2-3 cm tumors, both OS and RFS were significantly lower in the sublobar resection group. When consolidation-to-tumor ratio (CTR) ranged from 0.5 to <1, OS did not differ significantly, but RFS was significantly lower in sublobar resection. Lung cancers with CTR=1 showed significantly lower OS and RFS in the sublobar resection group. Segmentectomy provided similar OS and RFS compared to lobectomy, while wedge resection had a detrimental effect on patient prognosis. However, wedge resection may have provided comparable outcomes for patients aged 75 years or older.

CONCLUSION

Our findings suggest that segmentectomy and lobectomy yield similar oncological outcomes. However, compared to lobectomy, wedge resection is associated with a poorer prognosis. Nevertheless, for elderly patients, wedge resection is also a reasonable surgical option.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 2: systematic review of evidence regarding resection extent in generally healthy patients

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options (lobectomy, segmentectomy, wedge, stereotactic body radiotherapy, thermal ablation), weighing multiple outcomes (e.g., short-, intermediate-, long-term) and multiple aspects of each (e.g., magnitude of a difference, the degree of confidence in the evidence, and the applicability to the patient and setting at hand). A structure is needed to summarize the relevant evidence for an individual patient and to identify which outcomes have the greatest impact on the decision-making.

Methods

A PubMed systematic review from 2000-2021 of outcomes after lobectomy, segmentectomy and wedge resection in generally healthy patients is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons with at least some adjustment for confounders. The analysis involved careful assessment, including characteristics of patients, settings, residual confounding etc. to expose degrees of uncertainty and applicability to individual patients. Evidence is summarized that provides an at-a-glance overall impression as well as the ability to delve into layers of details of the patients, settings and treatments involved.

Results

In healthy patients there is no short-term benefit to sublobar resection vs. lobectomy in randomized and non-randomized comparisons. A detriment in long-term outcomes is demonstrated by adjusted non-randomized comparisons, more marked for wedge than segmentectomy. Quality-of-life data is confounded by the use of video-assisted approaches; evidence suggests the approach has more impact than the resection extent. Differences in pulmonary function tests by resection extent are not clinically meaningful in healthy patients, especially for multi-segmentectomy vs. lobectomy. The margin distance is associated with the risk of recurrence.

Conclusions

A systematic, comprehensive summary of evidence regarding resection extent in healthy patients with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation on which to build a framework for individualized clinical decision-making.

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.

Pulmonary function after segmentectomy versus lobectomy in patients with early-stage non-small-cell lung cancer: a meta-analysis

Objective

Segmentectomy is widely performed for early-stage lung cancer. However, the effects of segmentectomy versus lobectomy on pulmonary function remain unclear. We performed a meta-analysis with the aim of comparing segmentectomy and lobectomy in terms of preservation of pulmonary function in patients with early-stage non-small-cell lung cancer (NSCLC).

Methods

We conducted a literature search of PubMed using the terms ‘pulmonary function’ AND ‘segmentectomy’ AND ‘lobectomy’. The primary outcomes of interest were the forced expiratory volume in 1 second (FEV1), FEV1 as percent of predicted (%FEV1), change in FEV1 (Δ%FEV1), and the ratio of postoperative to preoperative FEV1.

Results

Thirteen studies comprising 2027 patients met the inclusion and exclusion criteria and were included for analysis, including 787 patients in the segmentectomy group and 1240 patients in the lobectomy group. Patients in the segmentectomy group showed significantly better preservation of FEV1 and %FEV1 compared with the lobectomy group. The reduction in FEV1 after surgery was significantly less in the segmentectomy group compared with the lobectomy group, and Δ%FEV1 was significantly higher in the segmentectomy group than in the lobectomy group.

Conclusion

Segmentectomy results in better preservation of pulmonary function compared with lobectomy in patients with early-stage NSCLC.

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.

Complication and lung function impairment prediction using perfusion and computed tomography air trapping (CLIPPCAIR): protocol for the development and validation of a novel multivariable model for the prediction of post-resection lung function

Background

Recent advancements in computed tomography (CT) scanning and post processing have provided new means of assessing factors affecting respiratory function. For lung cancer patients requiring resection, and especially those with respiratory comorbidities such as chronic obstructive pulmonary disease (COPD), the ability to predict post-operative lung function is a crucial step in the lung cancer operability assessment. The primary objective of the CLIPPCAIR study is to use novel CT data to develop and validate an algorithm for the prediction of lung function remaining after pneumectomy/lobectomy.

Methods

Two sequential cohorts of non-small cell lung cancer patients requiring a pre-resection CT scan will be recruited at the Montpellier University Hospital, France: a test population (N=60) on which predictive models will be developed, and a further model validation population (N=100). Enrolment will occur during routine pre-surgical consults and follow-up visits will occur 1 and 6 months after pneumectomy/lobectomy. The primary outcome to be predicted is forced expiratory volume in 1 second (FEV1) six months after lung resection. The baseline CT variables that will be used to develop the primary multivariable regression model are: expiratory to inspiratory ratios of mean lung density (MLD_e/i for the total lung and resected volume), the percentage of voxels attenuating at less than ‒950 HU (PVOX_‒950 for the total lung and resected volume) and the ratio of iodine concentrations for the resected volume over that of the total lung. The correlation between predicted and real values will be compared to (and is expected to improve upon) that of previously published methods. Secondary analyses will include the prediction of transfer factor for carbon monoxide (TLCO) and complications in a similar fashion. The option to explore further variables as predictors of post-resection lung function or complications is kept open.

Discussion

Current methods for estimating post-resection lung function are imperfect and can add assessments (such as scintigraphy) to the pre-surgical workup. By using CT imaging data in a novel fashion, the results of the CLIPPCAIR study may not only improve such estimates, it may also simplify patient pathways.

Trial registration

Clinicaltrials.gov (NCT03885765).

Propensity-matched Comparison of VATS Left Upper Tri-segmentectomy and Lobectomy

BACKGROUND

This study aims to investigate the oncological outcomes of video-assisted thoracoscopic (VATS) left upper tri-segmentectomy (LTS) versus left upper lobectomy (LUL) for patients presenting with stage I non-small-cell lung cancer (NSCLC).

METHODS

A retrospective analysis identified 1543 consecutive patients presenting to Shanghai Pulmonary Hospital with NSCLC for VATS-LTS or LUL from 2013-2017. After propensity-score matching for patient demographics and tumor characteristics, 273 pairs were identified. Disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method and compared using the Log-rank test.

RESULTS

The median follow-up time was 51.5 months. There were no significant differences in operative duration (2.11±0.64 versus 2.49±5.96 h, p=0.30), total blood loss (106.19±170.83 versus 97.07±149.34 mL, p=0.51) and operation complications (10% versus 8%, p=0.37) between LUL and LTS. Patients undergoing LUL had longer postoperative hospital stay (5.55±3.00 versus 4.87±2.33 days, p=0.003), greater tumor margin distance (3.3±1.2 versus 3.1±0.9 cm, p＜.001) and greater number of lymph nodes harvested (8.0±3.2 versus 6.8±3.3, p＜.001) than LTS, but the margin/tumor ratio was not statistically different (2.5±1.6 versus 2.3±1.1, p=0.11). Median DFS (49.5 versus 54.3 months, p=0.77) and OS (49.5 versus 55.0 months, p=0.88) were not significantly different between patients undergoing LTS and LUL, and similar outcomes were noted across subgroups of patients stratified by tumor stages, pathological type, and radiographic manifestations.

CONCLUSIONS

VATS-LTS and LUL had comparable oncological outcomes for stage I NSCLC, regardless of tumor pathological types and radiological findings, as long as negative margins were confirmed.

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.

[A Retrospective Study of Microporous Polysaccharide Hemostatic Powder Combined with Other Repair Materials for Reducing Postoperative Pulmonary Air Leakage during Pulmonary Segmentectomy]

背景与目的

解剖性肺段切除术在肺结节及早期肺癌中的应用愈加广泛，术后肺漏气是其术后常见并发症之一。本研究旨在探究胸腔镜下精准肺段切除手术术中修补材料的应用对于减少术后肺漏气的效果。

方法

本研究纳入2018年8月1日-2019年7月31日在江苏省人民医院胸外科拟行胸腔镜下肺段切除术的入院患者，根据术中处理段间交界面时使用材料的差异进行分组：采用微孔多聚糖止血粉+纤维蛋白粘合胶+可吸收性聚乙醇酸补片的患者划分为A组，而采用纤维蛋白粘合胶+可吸收性聚乙醇酸补片的患者划分为B组。收集并记录所有患者的术前基础信息及术后的每日胸腔引流量、胸腔引流管的留置时间、拔除胸腔引流管前的胸片、拔除胸腔引流管后的胸片、血常规以及术后住院时间，并分析术中修补材料的应用对术后肺漏气的影响。

结果

两组患者胸腔引流管留置时间（P=0.019）、术后住院时间（P=0.017）具有统计学差异。

结论

在肺段切除术中段间交界面的处理上使用微孔多聚糖止血粉+纤维蛋白粘合胶+可吸收性聚乙醇酸补片相比于使用纤维蛋白粘合胶+可吸收性聚乙醇酸补片能更好地减少患者术后漏气的发生及缩短术后住院时间。

Systematic review and meta-analysis of video-assisted thoracoscopic surgery segmentectomy versus lobectomy for stage I non-small cell lung cancer

BACKGROUND

Whether video-assisted thoracoscopic surgery (VATS) segmentectomy and VATS lobectomy provide similar perioperative and oncological outcomes in stage I non-small cell lung cancer (NSCLC) is still controversial.

METHODS

Meta-analysis of 12 studies comparing outcomes after VATS lobectomy and VATS segmentectomy for stage I NSCLC. Data were analyzed by the RevMan 5.3 software.

RESULTS

Disease-free survival (HR 1.19, 95% CI 0.89 to 1.33, P = 0.39), overall survival (HR 1.11, 95% CI 0.89 to 1.38, P = 0.36), postoperative complications (OR = 1.10, 95% CI 0.69 to 1.75, P = 0.7), intraoperative blood loss (MD = 3.87, 95% CI - 10.21 to 17.94, P = 0.59), operative time (MD = 10.89, 95% CI - 13.04 to 34.82, P = 0.37), air leak > 5 days (OR = 1.20, 95% CI 0.66 to 2.17, P = 0.55), and in-hospital mortality (OR = 1.67, 95% CI 0.39 to 7.16, P = 0.49) were comparable between the groups. Postoperative hospital stay (MD = - 0.69, 95% CI - 1.19 to - 0.19, P = 0.007) and number of dissected lymph nodes (MD = - 6.44, 95%CI - 9.49 to - 3.40, P < 0.0001) were significantly lower in VATS segmentectomy patients.

CONCLUSIONS

VATS segmentectomy and VATS lobectomy provide similar oncological and perioperative outcomes for stage I NSCLC patients. This systematic review was registered on PROSPERO and can be accessed at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID = CRD42019133398.

Meta-analysis of segmentectomy versus lobectomy for radiologically pure solid or solid-dominant stage IA non-small cell lung cancer

OBJECTIVE

Whether segmentectomy can be used to treat radiologically determined pure solid or solid-dominant lung cancer remains controversial owing to the invasive pathologic characteristics of these tumors despite their small size. This meta-analysis compared the oncologic outcomes after lobectomy and segmentectomy regarding relapse-free survival (RFS) and overall survival (OS) in patients with radiologically determined pure solid or solid-dominant clinical stage IA non-small cell lung cancer (NSCLC).

METHODS

A literature search was performed in the MEDLINE, EMBASE, and Cochrane Central databases for information from the date of database inception to March 2019. Studies were selected according to predefined eligibility criteria. The hazard ratio (HR) and associated 95% confidence interval (CI) were extracted or calculated as the outcome measure for data combining.

RESULTS

Seven eligible studies published between 2014 and 2018 enrolling 1428 patients were included in the current meta-analysis. Compared with lobectomy, segmentectomy had a significant benefit on the RFS of radiologically determined pure solid or solid-dominant clinical stage IA NSCLC patients (combined HR: 1.46; 95% CI, 1.05-2.03; P = 0.024) and there were no significant differences on the OS of these patients (HR: 1.52; 95% CI, 0.95-2.43; P = 0.08).

CONCLUSIONS

Segmentectomy leads to lower survival than lobectomy for clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors. Moreover, applying lobectomy to clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors (≤2 cm) could lead to an even bigger survival advantage. However, there are some limitations in the present study, and more evidence is needed to support the conclusion.

[Difference of Lung Function Retention after Segmentectomy and Lobectomy]

近年来肺癌发病率和检出率逐渐升高，肺段切除术被越来越普遍应用于治疗早期非小细胞肺癌。有学者认为肺段切除术相比肺叶切除术更有利于术后肺功能的保留，也有研究得出两种手术方式在术后肺功能保留方面差异不大，本文就肺段切除术与肺叶切除术术后肺功能变化的相关研究作一综述。

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[The Initial Experience of Video-assisted Thoracic Surgery Segmentectomy for Early Stage Lung Cancer]

背景与目的

肺段切除较肺叶切除能够更多地保留健康肺组织，但其在早期肺癌根治性方面仍存在争议。本研究分析35例完全胸腔镜下解剖性肺段切除术临床病理资料并复习文献，探讨胸腔镜下肺段切除术在早期肺癌治疗中面临的问题。

方法

回顾北京大学第三医院2013年5月-2017年7月单一手术组35例完全胸腔镜下肺段切除术患者的临床病理资料，观察术中及术后并发症等安全性指标及淋巴结清扫数目、转移情况，并将术后病理类型与术前影像类型比对分析。35例肺段切除术中男性11例，女性24例，平均年龄57.7岁。病灶位于右肺上叶者8例，右肺下叶者8例，左肺上叶者13例，左肺下叶者6例。计算机断层扫描（computed tomography, CT）影像学肿瘤最大径平均12.7 mm，肺门及纵隔淋巴结最大直径均小于10 mm，以磨玻璃成为主者23例，以实性成分为主者12例。

结果

35例均顺利完成电视辅助胸腔镜手术（video-assisted thoracic surgery, VATS）解剖性肺段切除术，平均手术时间为153 min，出血量为51 mL。术后漏气10例，均未超过3天。健侧肺不张1例，乳糜胸1例。平均住院时间为6.1天。出院后30天内门诊复查未发生其他院外手术相关并发症。病理为转移瘤者2例，良性肺病8例，原发肺癌25例。25例原发肺癌中浸润性肺腺癌14例[CT以肺磨玻璃影（ground-glass opacity, GGO）为主者7例]，微小浸润腺癌4例（GGO为主者3例），原位腺癌6例（CT均为纯GGO），肺鳞癌1例（CT以实性成分为主）。25例肺癌平均切除淋巴结7.2枚，所有淋巴结无癌转移。

结论

VATS解剖性肺段切除术技术上安全可靠，其在肺癌治疗中适应症需严格掌握，其优势仍需前瞻性随机对照实验来证实。

CT quantitative parameters to predict the invasiveness of lung pure ground-glass nodules (pGGNs)

AIM

To investigate the value of computed tomography (CT) quantitative parameters in predicting the invasiveness of lung pure ground-glass nodules (pGGNs).

MATERIALS AND METHODS

Chest CT images and pathological findings of 163 pGGNs in 154 consecutive patients were reviewed. According to the clinical management strategies, cases were divided into pre-invasive and MIA groups (atypical adenomatous hyperplasia [AAH], adenocarcinoma in situ [AIS], and minimally invasive adenocarcinoma [MIA]) and invasive group (invasive adenocarcinoma [IAC]). CT quantitative parameters including maximum diameter, largest diameter perpendicular to the maximum diameter, maximum cross-sectional area, volume, mass, and mean attenuation value were measured and compared between two groups. Their diagnostic performances were evaluated using receiver operating characteristic (ROC) and logistic regression analysis.

RESULTS

Significant differences existed for all the CT quantitative parameters in both groups (p<0.01). The values of area under the curve (AUC) were 0.783 of maximum diameter (95% CI: 0.711-0.843), 0.779 of longest diameter perpendicular to maximum diameter (95% CI: 0.707-0.840), 0.796 of largest cross-sectional area (95% CI: 0.726-0.855), 0.781 of volume (95% CI: 0.710-0.842), 0.794 of mass (95% CI: 0.722-0.865) and 0.625 of mean attenuation value (95% CI: 0.546-0.700), respectively. A pairwise-manner comparison showed the AUC of mean attenuation value was the smallest (p<0.01). Logistic regression analysis showed the largest cross-sectional area (OR=2.307, 95% CI: 1.689-3.150) was the independent predictor for IAC with a cut-off value of 2.22 cm².

CONCLUSIONS

CT quantitative parameters could predict the invasiveness of lung pGGNs. The largest cross-sectional area is the most valuable independent predictor and the mean attenuation value is less valuable.

Lung segmentectomy: does it offer a real functional benefit over lobectomy?

Anatomical segmentectomy has been developed to offer better pulmonary function preservation than lobectomy, in stage IA lung cancer. Despite the retrospective nature of most of the studies and the lack of randomised studies, a substantial body of literature today allows us to evaluate to what extent lung function decreases after segmentectomy and whether segmentectomy offers a real functional benefit over lobectomy. From the available series, it emerges that the mean decrease in forced expiratory volume in 1 s (FEV1) is low, ranging from −9% to −24% of the initial value within 2 months and −3 to −13% 12 months after segmentectomy. This reduction in lung function is significantly lower than that induced by lobectomy, but saves only a few per cent of pre-operative FEV1. Moreover, the published results do not firmly establish the functional benefit of segmentectomy over lobectomy in patients with poor lung function. Some issues remain to be addressed, including whether video-assisted thoracic surgery (VATS) segmentectomy may preserve lung function better than VATS lobectomy in patients with poor lung function, especially within the early days after surgery, and whether this may translate to lowering the functional limit for surgery. Eventually, trials comparing stereotactic ablative body radiotherapy, radiofrequency ablation and segmentectomy functional consequences are warranted.

Analysis of the variation pattern in right upper pulmonary veins and establishment of simplified vein models for anatomical segmentectomy

OBJECTIVE

Thoracic surgeons must be erudite pulmonary vein variation when performing anatomical segmentectomy. We used three-dimensional CT (3DCT) to accumulate variations of the pulmonary veins of the right upper lobe (RUL) and created a simplified RUL vein model.

METHODS

We reviewed anatomical variations of the RUL pulmonary veins of 338 patients using 3DCT images, and classified them by position related with bronchus.

RESULTS

Of the "anterior" and "central" RUL veins, all could be classified into 4 types: 2 Anterior with Central types (Iab and Ib), 1 Anterior type, and 1 Central type. The Anterior with Central type was observed in 273 patients (81 %), and was further classified into two types according to the origin of the anterior vein. In the Iab type, the anterior vein originated from V1a to V1b (54 %) whereas, in the Ib type, the anterior vein originated from only V1b (26 %). The Central type, which had no anterior vein, was evident in 23 cases (7 %). These three types could be further divided into three subcategories by reference to the branching pattern of the central vein. The Anterior type, which had no central vein, was evident in 42 cases (12 %), and this type could be further categorized into two types, depending on the branching pattern of the anterior vein.

CONCLUSION

We created a simplified RUL vein model to facilitate anatomical segmentectomy. Our models should find wide application, especially when thoracic surgery requiring anatomical RUL segmentectomy is planned.

Comparison of treatment outcomes between single-port video-assisted thoracoscopic anatomic segmentectomy and lobectomy for non-small cell lung cancer of early-stage: a retrospective observational study

BACKGROUND

There are few reports of single-port video-assisted thoracoscopic surgery (S-VATS) anatomic segmentectomy and S-VATS lobectomy for early-stage non-small cell lung cancer (NSCLC) and no comparisons between them have yet been reported. Therefore, the aim of this study was to compare the safety and efficacy of S-VATS anatomic segmentectomy and S-VATS lobectomy for early-stage NSCLC.

METHODS

In this retrospective observational study, the outcomes of 79 consecutive patients who had undergone S-VATS anatomic segmentectomy (32 patients) or S-VATS lobectomy (47 patients) for early-stage NSCLC from April 2014 to June 2015 were examined. The operation time, intraoperative blood loss, numbers of dissected lymph nodes and mediastinal nodal stations, numbers of staples used, postoperative drainage volume and duration, duration of hospital stay, costs, postoperative complications, local recurrence, and survival were compared between these two groups.

RESULTS

The postoperative drainage volume was smaller and the postoperative drainage duration shorter in the S-VATS segmentectomy than the lobectomy group (P<0.05). There were no significant differences in operation time, intraoperative blood loss, number of staples used, number and stations of dissected mediastinal lymph nodes, duration of hospital stay, costs, or postoperative complications. At the time of writing, no deaths or local recurrences had occurred in either group.

CONCLUSIONS

S-VATS segmentectomy is as safe and effective as S-VATS lobectomy. Patients who undergo S-VATS segmentectomy seem to recover faster.

Predicting exercise capacity after lobectomy by single photon emission computed tomography and computed tomography

OBJECTIVES

This study compared the prediction of postoperative exercise capacity by employing lung perfusion scintigraphy images obtained with single photon emission computed tomography together with computed tomography (SPECT/CT) versus the common method of counting subsegments (SC method).

METHODS

In 18 patients scheduled for lobectomy, predicted postoperative maximum oxygen uptake per kilogram body weight ([Formula: see text]) was calculated by the SPECT/CT and SC methods. Correlations were examined between the [Formula: see text] predicted by SPECT/CT or the SC method, and the actual [Formula: see text] measured at 2 weeks (mean 15.4 ± 1.5 days) and 1 month (mean 29.1 ± 0.75 days) after surgery to determine whether SPECT/CT was more accurate than SC for predicting postoperative exercise capacity.

RESULTS

There was a significant positive correlation between the [Formula: see text] predicted by SPECT/CT and the actual value at 2 weeks (r = 0.802, p < 0.0001) or 1 month (r = 0.770, p < 0.0001). There was also a significant positive correlation between the [Formula: see text] predicted by SC and the actual value at 2 weeks (r = 0.785, p < 0.0001) or 1 month (r = 0.784, p < 0.0001).

CONCLUSIONS

This study showed that both SPECT/CT and the SC method were useful for predicting postoperative [Formula: see text] in the clinical setting.

Impact of Sublobar Resection on Pulmonary Function: Long-Term Results from American College of Surgeons Oncology Group Z4032 (Alliance)

BACKGROUND

Sublobar resection (SR) in high-risk operable patients may result in a long-term decrease in pulmonary function. We previously reported 3-month pulmonary function outcomes from a randomized phase III study of SR alone compared with SR with brachytherapy in patients with non-small cell lung cancer. We now report long-term pulmonary function after SR.

METHODS

Pulmonary function was measured at baseline and at 3, 12, and 24 months. A decline of 10% or more from baseline in the percentage predicted forced expiratory volume of 1 percentage or in the diffusion capacity of the lung for carbon monoxide was considered clinically meaningful. The effect of study arm, tumor location, size, approach (video-assisted thoracoscopic surgery vs thoracotomy), and SR type (wedge vs segmentectomy) on pulmonary function was assessed using a Wilcoxon rank sum test. A generalized estimating equation model was used to assess the effect of each factor on longitudinal data, including all four time points.

RESULTS

Complete pulmonary function data at all time points was available in 69 patients. No significant differences were observed in pulmonary function between SR and SR with brachytherapy, thus the study arms were combined for all analyses. A decline of 10% or more (p = 0.02) in the percentage predicted forced expiratory volume in 1 second was demonstrated for lower-lobe resections at 3 months but was not at 12 or 24 months. A decline of 10% or more (p = 0.05) in the percentage predicted diffusion capacity of the lung for carbon monoxide was seen for thoracotomy at 3 months but was not at 12 or 24 months.

CONCLUSIONS

Clinically meaningful declines in pulmonary function occurred after lower lobe resection and after thoracotomy at 3 months but subsequently recovered. This study suggests that SR does not result in sustained decreased pulmonary function in high-risk operable patients.

Non-intubated video-assisted thoracoscopic surgery anatomical resections: a new perspective for treatment of lung cancer

The lung isolation under general anaesthesia with double lumen tubes has become an indispensable part of video-assisted thoracoscopic surgery (VATS) for lung cancer. However, with an attempt to avoid the residual effects of muscle relaxants and the systemic complications due to tracheal intubation, anesthesia without tracheal intubation has also been applied in VATS surgeries for lung cancer. Currently, non-intubated anesthesia under spontaneous breathing has been widely applied in VATS, contributing to more stable anesthesia and lower rate of switching to intubated anesthesia. It can be applied in most VATS procedures including anatomical pulmonary lobectomy, anatomical segmentectomy, and radical resection for lung cancer. In the selected lung cancer patients, non-intubated anesthesia under spontaneous breathing makes the VATS procedures safer and more feasible. With an equal chance for surgery as the intubated anesthesia, this technique lowers the incidences of peri-operative complications and speeds up post-operative recovery. As a novel surgical option, the anatomic VATS under non-intubated anesthesia under spontaneous breathing have shown to be promising. Nevertheless, the long-term outcomes require further evaluation in more multi-center prospective clinical trials with larger sample sizes.

Improved prediction of lobar perfusion contribution using technetium-99m-labeled macroaggregate of albumin single photon emission computed tomography/computed tomography with attenuation correction

OBJECTIVE

Lung cancer resection can require removal of an entire lobe and, at times, bilobectomy or pneumonectomy. Many patients will also have significantly compromised lung function that requires limiting the extent of surgery or could preclude surgery altogether. The preoperative assessment should include predicted postoperative forced expiratory volume in 1 second (ppoFEV1), because a ppoFEV1 of <40% predicts significantly increased perioperative morbidity. The ppoFEV1 can be estimated by multiplying the preoperative FEV1 by the residual perfused territory percentage, as predicted on planar perfusion scintigraphy (PPS). However, ppoFEV1 using PPS has shown variable correlation with spirometry-measured postoperative FEV1.

METHODS

We propose an improved method for assessing regional lung perfusion in preoperative lung surgery patients. Patients undergo single photon emission computed tomography/computed tomography (SPECT/CT) imaging with attenuation correction using the conventional perfusion agent, technetium-99m-labeled macroaggregate of albumin. The CT image provides information for manual segmentation of each lobe. These segmentations are applied to the SPECT images to determine lobar perfusion. This proposed method was compared with PPS.

RESULTS

This technique was evaluated in 17 patients. As expected, the perfusion contributions of the right and left lungs, calculated from SPECT/CT, correlated closely with those obtained from PPS (Pearson r=0.995). However, the lobar perfusion contributions obtained by PPS and SPECT/CT were significantly different, by 2 methods of comparison (Hotelling's P=1.7×10(-6) and P=1.7×10(-4)).

CONCLUSIONS

This new SPECT/CT technique provides an anatomically more accurate assessment of lobar perfusion. This technique can refine which patients should be operative candidates and allow better prediction of postoperative function in contrast to the anatomically inaccurate planar scintigraphic predictions, which often underestimate the postoperative FEV1. This new technique is expected to have a significant effect on the resectability of patients with lung cancer.

Analysis of feasibility and safety of complete video-assisted thoracoscopic resection of anatomic pulmonary segments under non-intubated anesthesia

OBJECTIVE

To explore the feasibility and safety of complete video-assisted thoracoscopic surgery (C-VATS) under non-intubated anesthesia for the resection of anatomic pulmonary segments in the treatment of early lung cancer (T1N0M0), benign lung diseases and lung metastases.

METHODS

The clinical data of patients undergoing resection of anatomic pulmonary segments using C-VATS under non-intubated anesthesia in the First Affiliated Hospital of Guangzhou Medical University from July 2011 to November 2013 were retrospectively analyzed to evaluate the feasibility and safety of this technique.

RESULTS

The procedures were successfully completed in 15 patients, including four men and eleven women. The average age was 47 [21-74] years. There were ten patients with adenocarcinoma, one with pulmonary metastases, and four with benign lung lesions. The resected sites included: right upper apical segment, two; right lower dorsal segment, one; right lower basal segment, two; left upper lingular segment, three; left upper apical segment, one; left upper anterior apical segment, two; left upper posterior segment, one; left lower basal segment, one; left upper posterior and apical segments, one; and left upper anterior and apical segments plus wedge resection of the posterior segment, one. One case had intraoperative bleeding, which was controlled with thoracoscopic operation and no blood transfusion was required. No thoracotomy or perioperative death was noted. Two patients had postoperative bleeding without the need for blood transfusions, and were cured and discharged. The pathologic stage for all patients with primary lung cancer was IA. After 4-19 months of follow-up, no tumor recurrence and metastasis was found. The overall mean operative length was 166 minutes (range 65-285 minutes), mean blood loss 75 mL (range 5-1,450 mL), mean postoperative chest drainage 294 mL (range 0-1,165 mL), mean chest drainage time 2 days (range 0-5 days), and mean postoperative hospital stay 5 days (range 3-8 days).

CONCLUSIONS

Complete video-assisted throacoscopic segmentectomy under anesthesia without endotracheal intubation is a safe and feasible technique that can be used to treat a selected group of IA patients with primary lung cancer, lung metastases and benign diseases.

Management of single malignant lung nodules in elderly patients (70 years or older) who are not candidates for lobectomy

PURPOSE

The aim of this study was to evaluate and compare sublobar resection plus intraoperative seed implant (IOS) versus stereotactic body radiation therapy (SBRT) in patients with single malignant lung nodules in patients 70 years of age or older.

MATERIALS AND METHODS

A retrospective chart review was performed and 47 patients with adequate information were selected for analysis. Thirty patients with single malignant lung nodules received SBRT. Seventeen patients received limited surgical resection plus radioactive seed implantation for solitary malignant lung nodules. Univariate statistical analysis showed a significant difference only for the age in the 2 groups: the mean age in the radioactive seed group, 78.8 years versus 76.1 years in the SBRT group (2-sided, P=0.05).

RESULTS

There was high local control and minimal toxicity with either treatment modality and no significant difference among the 2 groups in terms of local control, survival, and toxicity. However, the distant failure was higher but not statistically significant in the SBRT group (9 of 30 patients in SBRT vs. 0 of 17 in IOS, P=0.1).

CONCLUSIONS

Our study has shown excellent outcomes and limited toxicity in both IOS and SBRT for treatment of single malignant lung nodules in patients who are not candidates for lobectomy. However, a randomized trial is needed in this group of elderly patients to determine the most appropriate treatment.

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.

Multiple segmentectomy for synchronous multiple small peripheral lung cancers: report of two cases

Treatment strategies for synchronous, multiple peripheral lung cancers remain controversial. Bilobectomy for multiple lung cancers could cause pulmonary function impairment. We report two patients with synchronous multiple peripheral non-small cell lung cancers, who underwent multiple segmentectomy simultaneously. This is the first report of consecutive segmentectomy of two segments.

Innovative segmentectomy to remove the posterior segment of the lower lobe (S¹⁰) of the lung

We describe our innovative technique for performing segmentectomy of the posterior segment of the lower lobe of the lung, being segment number 10 (S¹⁰). In segmentectomy of S¹⁰, it is difficult to identify A¹⁰ from the interlobar fissure because the pulmonary artery to S¹⁰ (A¹⁰) branches from A(9+10) and runs dorsally and deeply into the lung tissue. Moreover, to reach S¹⁰ from the interlobar fissure, the lung tissue should be cut between S⁶ and S⁸, because S¹⁰ is not located beside the interlobar fissure. However, it is difficult to identify the boundary between the S⁶ and S⁸ without a route marker. To solve these difficulties, we divided S⁶ and S¹⁰ from each other at the beginning of the procedure, which enabled A¹⁰ to be identified easily from the dorsal side. Because S⁶ and S(8-10) should be divided in S¹⁰ segmentectomy at the end, the division between S⁶ and S(8-10) at the beginning of procedure is not only reasonable, but makes the procedure simple.

Combined subsegmentectomy for S(2)(b) (horizontal subsegment of the posterior segment) and S(3)(a) (lateral subsegment of the anterior segment) in the right upper pulmonary lobe

A technique for combined resection of S(2)(b) (horizontal subsegment of the posterior segment) and S(3)(a) (lateral subsegment of the anterior segment) of the right upper lobe of the lung is presented. Although both the S(2)(b) and S(3)(a) should be resected from the interlobar fissure, an approach for the artery and bronchus of S(3)(a) (A(3)(a) and B(3)(a), respectively) is easier from the ventral side of the hilum rather than from the interlobar fissure, because B(3) runs in back of V(2) at the interlobar fissure. To resolve this contradiction, we devised a procedure as follows: (1) A(2)(b) and B(2)(b) are cut at the interlobar fissure; (2) A(3)(a) and B(3)(a) are cut from the ventral side of hilum; (3) the peripheral stumps of A(3)(a) and B(3)(a) are transferred to the interlobar fissure; and (4) subsegments of S(3)(a) and S(2)(b) are resected with the peripheral stumps of A(2)(b), B(2)(b), A(3)(a), and B(3)(a) from the side of the interlobar fissure. We believe this procedure makes the combined resection of S(2)(b) and S(3)(a) easy.

The impact of adjuvant brachytherapy with sublobar resection on pulmonary function and dyspnea in high-risk patients with operable disease: preliminary results from the American College of Surgeons Oncology Group Z4032 trial

BACKGROUND

Z4032 was a randomized study conducted by the American College of Surgeons Oncology Group comparing sublobar resection alone versus sublobar resection with brachytherapy for high-risk operable patients with non-small cell lung cancer (NSCLC). This evaluates early impact of adjuvant brachytherapy on pulmonary function tests, dyspnea, and perioperative (30-day) respiratory complications in this impaired patient population.

METHODS

Eligible patients with stage I NSCLC tumors 3 cm or smaller were randomly allocated to undergo sublobar resection with (SRB group) or without (SR group) brachytherapy. Outcomes measured included the percentage predicted forced expiratory volume in 1 second (FEV1%), percentage predicted carbon monoxide diffusion capacity (DLCO%), and dyspnea score per the University of California San Diego Shortness of Breath Questionnaire. Pulmonary morbidity was assessed per the Common Terminology Criteria for Adverse Events version 3.0. Outcomes were measured at baseline and 3 months. A 10% change in pulmonary function test or 10-point change in dyspnea score was deemed clinically meaningful.

RESULTS

Z4032 permanently closed to patient accrual in January 2010 at 224 patients. At 3-month follow-up, pulmonary function data are currently available for 148 (74 SR and 74 SRB) patients described in this report. There were no differences in baseline characteristics between arms. In the SR arm, 9 patients (12%) reported grade 3 respiratory adverse events, compared with 12 (16%) in the SRB arm (P = .49). There was no significant change in percentage change in DLCO% or dyspnea score from baseline to 3 months within either arm. In the case of FEV1%, percentage change from baseline to 3 months was significant within the SR arm (P = .03), with patients reporting improvement in FEV1% at month 3. Multivariable regression analysis (adjusted for baseline values) showed no significant impact of treatment arm, tumor location (upper vs other lobe), or surgical approach (video-assisted thoracoscopic surgery vs thoracotomy) on 3-month FEV1%, DLCO%, and dyspnea score. There was no significant difference in incidence of clinically meaningful (10% pulmonary function or 10-point dyspnea score change) change between arms. Twenty-two percent of patients with lower-lobe tumors and 9% with upper-lobe tumors demonstrated 10% decline in FEV1% (odds ratio, 2.79; 95 confidence interval, 1.07-7.25; P = .04).

CONCLUSIONS

Adjuvant intraoperative brachytherapy in conjunction with sublobar resection did not significantly worsen pulmonary function or dyspnea at 3 months in a high-risk population with NSCLC, nor was it associated with increased perioperative pulmonary adverse events. Lower-lobe resection was the only factor significantly associated with clinically meaningful decline in FEV1%.

Semiquantification and classification of local pulmonary function by V/Q single photon emission computed tomography in patients with non-small cell lung cancer: potential indication for radiotherapy planning

INTRODUCTION

Perfusion (Q) single photon emission computed tomography (SPECT) has been used to divert dose away from higher-functioning lung during radiation therapy (RT) planning. This study aimed to (1) study regional lung function through coregistered pulmonary ventilation/perfusion (V/Q)-SPECT-CT and (2) classify these defects for its potential value in radiation planning in patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with stages I to III NSCLC requiring radiation-based therapy were eligible for this prospective study. V/Q-SPECT performed within 2 weeks before the start of radiation was interpreted by nuclear medicine physicians and then measured by a semiquantitative score. The potential mechanism of V and Q defects was analyzed; the potential impact of V/Q-SPECT over Q-SPECT alone was completed through classified applications (high-dose RT versus RT avoidance) during planning.

RESULTS

Images of 51 consecutive patients were analyzed. The V and Q defects were matched, reverse mismatched (V defect > Q defect), and mismatched (Q defect > V defect) in 61, 31, and 8% of patients, respectively. Tumor was the leading cause of the defects of ipsilateral lung in 73% of patients. The defect scores of the ipsilateral lung were greater in patients with central primaries than those with peripheral primaries for both V-SPECT (2.3 ± 1.1 versus 1.5 ± 0.8, p = 0.017) and Q-SPECT (2.2 ± 0.8 versus 1.4 ± 0.6, p = 0.000). The patients with chronic obstructive pulmonary disease had greater defect scores in contralateral lung for both V-SPECT (1.5 ± 0.7 versus 1.0 ± 0.8, p = 0.006) and Q-SPECT (1.4 ± 0.6 versus 1.0 ± 0.4, p = 0.010). On assessing the potential value of SPECT on RT plan, 39% of patients could have their RT plan when applying V/Q-SPECT rather than Q-SPECT alone.

CONCLUSIONS

V/Q-SPECT provides a more comprehensive functional assessment, may provide additional value over Q-SPECT alone in assessing local pulmonary function, and guide RT plan decisions in patients with NSCLC.

Comparison of postoperative pulmonary function and air leakage between pleural closure vs. mesh-cover for intersegmental plane in segmentectomy

Background

To prevent postoperative air leakage after lung segmentectomy, we used two methods for the intersegmental plane: closing it by suturing the pleural edge (pleural closure), or opening it with coverage using polyglycolic acid mesh and fibrin glue (mesh-cover). The preserved forced expiratory volume in one second (FEV₁) of each lobe and the postoperative air leakage were compared between the two groups.

Methods

For 61 patients who underwent pleural closure and 36 patients who underwent mesh-cover, FEV₁ of the lobe before and after segmentectomy was measured using lung-perfusion single-photon-emission computed tomography and CT (SPECT/CT). The groups' results were compared, revealing differences of the preserved FEV₁ of the lobe for several segmentectomy procedures and postoperative duration of chest tube drainage.

Results

Although left upper division segmentectomy showed higher preserved FEV₁ of the lobe in the mesh-cover group than in the pleural closure one (p = 0.06), the other segmentectomy procedures showed no differences between the groups. The durations of postoperative chest drainage in the two groups (2.0 ± 2.5 vs. 2.3 ± 2.2 days) were not different.

Conclusions

Mesh-cover preserved the pulmonary function of remaining segments better than the pleural closure method in left upper division segmentectomy, although no superiority was found in the other segmentectomy procedures. However, the data include no results obtained using a stapler, which cuts the segment without recognizing even the intersegmental plane and the intersegmental vein. Mesh-cover prevented postoperative air leakage as well as the pleural closure method did.

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

OBJECTIVE

Cutting the intersegmental plane by using a stapler during segmentectomy might interfere with the expansion of the preserved lung due to visceral pleura caught in a staple line, especially in a large regional segmentectomy, such as left upper division or basal segmentectomy. We compared the preserved lung volume after segmentectomy among the methods using stapler, sharp dissection, and their combination for cutting the intersegmental plane in ex vivo pig lungs. We also examined a covering effect of polyglycolic acid mesh and fibrin glue.

METHODS

To assume a large regional segmentectomy in clinical practice, segments of the left caudal lobe except the lateral segment 2 (L2 segment) were resected, and the lung volume of the preserved L2 segment was measured. The intersegmental plane was cut by the following three methods: (1) stapler (n = 8); (2) scissors (n = 8); and (3) the combined method, that is, cutting the shallow lung tissue with scissors and the deep one with stapler (n = 8). The opened intersegmental plane was covered with polyglycolic acid mesh and fibrin glue. The air leakage was checked by injecting air through the bronchus at pressures of up to 30 cmH(2)O. Thereafter, normal saline was injected through the bronchus at pressures of 10, 20, and 30 cmH(2)O, to measure lung volumes by the volume-displacement method.

RESULTS

Polyglycolic acid mesh and fibrin glue prevented air leakage completely at up to 30 cmH(2)O. At the saline injection pressures of 10, 20, and 30 cmH(2)O, the mean volumes of L2 segment were 72 ± 14, 96 ± 14, and 109 ± 26 ml with the stapler; 86 ± 11, 117 ± 19, and 135 ± 39 ml with scissors; and 98 ± 10, 140 ± 20, and 155 ± 40 ml with the combined methods, respectively. The volume of the preserved L2 segment was significantly lower with the stapler method than with either the scissors or combined method at each pressure (p < 0.01). The difference was not significant between the scissors and combined methods.

CONCLUSIONS

Coverage with polyglycolic acid mesh and fibrin glue prevented air leakage from the opened intersegmental plane. The stapler interferes with the expansion of preserved lung in comparison to scissors or combined methods in a large regional segmentectomy.

Combined subsegmentectomy: postoperative pulmonary function compared to multiple segmental resection

Background

For small peripheral c-T1N0M0 non-small cell lung cancers involving multiple segments, we have conducted a resection of subsegments belonging to different segments, i.e. combined subsegmentectomy (CSS), to avoid resection of multiple segments or lobectomy. Tumor size, location of tumor, and forced expiratory volume in 1 second (FEV₁) of each preserved lobe were compared among the CSS, resection of single segment, and that of multiple segments.

Methods

FEV₁ of each preserved lobe were examined in 17 patients who underwent CSS, 56 who underwent resection of single segment, and 41 who underwent resection of multiple segments, by measuring pulmonary function and lung-perfusion single-photon-emission computed tomography and computed tomography before and after surgery.

Results

Tumor size in the CSS was significantly smaller than that in the resection of multiple segments (1.4 ± 0.5 vs. 2.0 ± 0.8 cm, p = 0.002). Tumors in the CSS were located in the right upper lobe more frequently than those in the resection of multiple segments (53% vs. 5%, p < 0.001). Postoperative of FEV₁ of each lobe after the CSS was higher than that after the resection of multiple segments (0.3 ± 0.2 vs. 0.2 ± 0.2 l, p = 0.07). Mean FEV₁ of each preserved lobe per subsegment after CSS was significantly higher than that after resection of multiple segments (0.05 ± 0.03 vs. 0.03 ± 0.02 l, p = 0.02). There was no significant difference of these factors between the CSS and resection of single segment.

Conclusions

The CSS is effective for preserving pulmonary function of each lobe, especially for small sized lung cancer involving multiple segments in the right upper lobe, which has fewer segments than other lobes.