Lobectomy versus segmentectomy: a propensity score-matched comparison of postoperative complications, pulmonary function and prognosis

An analysis of residual lung volume changes after segmentectomy based on three-dimensional computed tomography

Background

Based on the results of JCOG0802 and CALGB studies, segmentectomy has considered to be a standard procedure for early-stage non-small cell lung cancer (NSCLC). After lobectomy, the residual cavity is filled with mediastinal and diaphragmatic deviations, and compensatory volume changes are present in the residual lungs. In this study, we examined the efficacy of segmentectomy, a surgical procedure, by focusing on its impact on postoperative lung volume and function.

Methods

We enrolled 77 patients who underwent segmentectomy as their initial surgical procedure, excluding those with additional lung resections and those who lacked postoperative computed tomography imaging. The predicted residual volume (mL) was defined as the total lung volume before surgery minus the volume of the resected area. Using the predicted residual volume (mL) and postoperative total lung volume (mL), we calculated the rate of postoperative lung volume increase [(postoperative total lung volume/predicted residual volume) × 100] (%). We also classified 52 cases with a rate of postoperative lung volume increase of ≥100% into a compensatory group, while those with a rate of <100% were classified into a non-compensatory group.

Results

The average postoperative lung volume increase was 104.6% among 77 cases. Age ≥65 years, pack year index ≥27.5, ≥3 resected segments, and use of electrocautery for intersegmental plane division were significantly associated with compensatory group classification. In 20 compensatory cases with preoperative and postoperative pulmonary function tests, postoperative vital capacity and forced expiratory volume in one second values exceeded the preoperative predictions. This study further examined the areas responsible for postoperative compensatory lung volume increase. In the compensatory group, significant expansion was observed in the ipsilateral lobes, excluding the resected segment and contralateral lung, while no significant changes were noted in the volume of the lobe, including the resected segment. Conversely, the non-compensatory group showed a significant volume decrease in the resected lobe, but no significant increase in other areas.

Conclusions

This study emphasizes the importance of preserving lung segments in segmentectomy. The study demonstrates extensive compensatory volume changes in the ipsilateral lung and contralateral lung. There was no significant volume decrease in any residual segment. This underlines the potential of segmentectomy to maintain lung function and expand treatment options post-surgery. In addition, the compensated group included patients with a lower pack-year index and younger patients. These results suggest that postoperative compensatory lung expansion includes not only hyperinflation of the remaining lung, but also an increase in the functional lung parenchyma.

Survival outcomes of segmentectomy and lobectomy for early stage non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The question of whether segmentectomy and lobectomy have similar survival outcomes for patients with early-stage non-small cell lung cancer (NSCLC) is a matter of debate.

METHODS

A cohort study and randomized controlled trial were included, comparing segmentectomy and lobectomy, by utilizing computerized access to the Pubmed, Web of Science, and Cochrane Library databases up until July 2022. The Cochrane Collaboration tool was used to evaluate the randomized controlled trials, while the Newcastle-Ottawa Scale (NOS) was used to evaluate the cohort studies. Sensitivity analyses were also carried out.

RESULTS

The analysis incorporated 17 literature studies, including one randomized controlled trial and 16 cohort studies, and was divided into a segmentectomy group (n = 2081) and a lobectomy group (n = 2395) based on the type of surgery the patient underwent. Each study was followed up from 27 months to 130.8 months after surgery. Over survival (OS): HR = 1.14, 95%CI(0.97,1.32), P = 0.10; disease-free survival (DFS): HR = 1.13, 95%CI(0.91,1.41), P = 0.27; recurrence-free survival (RFS): HR = 0.95, 95%CI(0.81,1.12), P = 0.54.

CONCLUSION

The results of the study suggest that the survival outcomes of the segmentectomy group were not inferior to that of the lobectomy group. Segmentectomy should therefore be considered as a treatment option for early stage NSCLC.

Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy: A Retrospective Study

PURPOSE

We elucidated the effects of planned resection volume on postoperative pulmonary function and changes in residual lung volume during segmentectomy.

METHODS

This study included patients who underwent thoracoscopic segmentectomy between January 2017 and December 2022 and met eligibility criteria. Pre- and post-resection spirometry and computed tomography were performed. Three-dimensional reconstructions were performed by using computed tomography images to calculate the volumes of the resected, remaining, and nonoperative side regions. Based on the resected region volume, patients were divided into the higher and lower volume segmentectomy groups. Changes in lung volume and pulmonary function before and after the surgery were comparatively analyzed.

RESULTS

The median percentage of resected lung volume was 10.9%, forming the basis for categorizing patients into the two groups. Postoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) ratios to preoperative measurements in both groups did not differ significantly (FEV1, p = 0.254; FVC, p = 0.777). Postoperative FEV1 and FVC ratios to their predicted postoperative values were significantly higher in the higher volume segmentectomy group than in the lower volume segmentectomy group (FEV1, p = 0003; FVC, p < 0.001). The higher volume segmentectomy group showed significantly greater post-to-preoperative lung volume ratio in overall, contralateral, ipsilateral, residual lobe and residual segment than the lower volume segmentectomy group.

CONCLUSIONS

Postoperative respiratory function did not differ significantly between the higher- and lower-volume segmentectomy groups, indicating improved respiratory function because of substantial postoperative residual lung expansion. Our findings would aid in determining the extent of resection during segmentectomy.

Complete anatomic segmentectomy shows improved oncologic outcomes compared to incomplete anatomic segmentectomy

OBJECTIVES

To compare oncologic outcomes after segmentectomy with division of segmental bronchus, artery and vein (complete anatomic segmentectomy) versus segmentectomy with division of <3 segmental structures (incomplete anatomic segmentectomy).

METHODS

We conducted a single-centre, retrospective analysis of patients undergoing segmentectomy from March 2005 to May 2020. Operative reports were audited to classify procedures as complete or incomplete anatomic segmentectomy. Patients who underwent neoadjuvant therapy or pulmonary resection beyond indicated segments were excluded. Survival was estimated with Kaplan-Meier models and compared using log-rank tests. Cox proportional hazards models were used to estimate hazard ratios (HRs) for death. Cumulative incidence functions for loco-regional recurrence were compared with Gray's test, with death considered a competing event. Cox and Fine-Gray models were used to estimate cause-specific and subdistribution HRs, respectively, for loco-regional recurrence.

RESULTS

Of 390 cases, 266 (68.2%) were complete and 124 were incomplete anatomic segmentectomy. Demographics, pulmonary function, tumour size, stage and perioperative outcomes did not significantly differ between groups. Surgical margins were negative in all but 1 case. Complete anatomic segmentectomy was associated with improved lymph node dissection (5 vs 2 median nodes sampled; P < 0.001). Multivariable analysis revealed reduced incidence of loco-regional recurrence (cause-specific HR = 0.42; 95% confidence interval 0.22-0.80; subdistribution HR = 0.43; 95% confidence interval 0.23-0.81), and non-significant improvement in overall survival (HR = 0.66; 95% confidence interval: 0.43-1.00) after complete versus incomplete anatomic segmentectomy.

CONCLUSIONS

This single-centre experience suggests complete anatomic segmentectomy provides superior loco-regional control and may improve survival relative to incomplete anatomic segmentectomy. We recommend surgeons perform complete anatomic segmentectomy and lymph node dissection whenever possible.

[Recent Advances in Diagnosis and Treatment Strategies for Multiple Primary Lung Cancer]

As the utilization of computed tomography in lung cancer screening becomes more prevalent in the post-pandemic era, the incidence of multiple primary lung cancer (MPLC) has surged in various countries and regions. Despite the continued application of advanced histologic and sequencing technologies in this research field, the differentiation between MPLC and intrapulmonary metastasis (IM) remains challenging. In recent years, the specific mechanisms of genetic and environmental factors in MPLC have gradually come to light. Lobectomy still predominates in the treatment of MPLC, but the observation that tumor-specific sublobar resection has not detrimentally impacted survival appears to be a viable option. With the evolution of paradigms, the amalgamated treatment, primarily surgical, is an emerging trend. Among these, stereotactic ablative radiotherapy (SABR) and lung ablation techniques have emerged as efficacious treatments for early unresectable tumors and control of residual lesions. Furthermore, targeted therapies for driver-positive mutations and immunotherapy have demonstrated promising outcomes in the postoperative adjuvant phase. In this manuscript, we intend to provide an overview of the management of MPLC based on the latest discoveries.
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Efficacy of thoracoscopic segmentectomy versus lobectomy in the treatment of early invasive lung adenocarcinoma: a propensity score matching study

Objective

This study aimed to investigate and analyze the clinical application value of thoracoscopic segmentectomy and lobectomy in patients with invasive pulmonary adenocarcinoma.

Methods

286 patients with invasive pulmonary adenocarcinoma who underwent segmentectomy or lobectomy at the First Hospital of Jiaxing City from January 2018 to June 2020 were retrospectively analyzed. Patients were divided into a thoracoscopic segmentectomy group(n=97) and a lobectomy group (n=189). Patients were compared after obtaining 1:1 propensity score-matched cohorts. Outcome indicators included surgery-related indicators, immune-inflammation-related indicators, postoperative complications, recurrence, and metastasis.

Results

After 1:1 propensity score matching, 93 patients were included in each group. We found that the volume of intraoperative blood loss in the segmentectomy group was significantly less than in the lobectomy group (P=0.014). The duration of postoperative drainage (P = 0.005) and hospitalization (P=0.002) in the segmentectomy group were significantly shorter than in the lobectomy group. In terms of immunoinflammatory response, compared with the lobectomy group, white blood cells, neutrophils, SII, and NLR in the segmentectomy group were significantly lower than in the lobectomy group (P< 0.05). The recurrence-free survival (RFS) rates in the segmentectomy and lobectomy were 80.5% and 88.2% at 1 year and 35.1% and 52.6% at 3 years, respectively, and the difference was statistically significant (P<0.05). The segmentectomy group achieved similar outcomes to the lobectomy group at 1 year and 3 years (P > 0.05). Multivariate COX regression analysis showed that CAR was an independent risk factor for RFS in patients undergoing invasive adenocarcinoma surgery.

Conclusion

Compared with lobectomy, thoracoscopic segmentectomy can effectively reduce the postoperative inflammatory response in patients with early invasive lung adenocarcinoma and promote patient recovery. Although segmentectomy is associated with a higher recurrence rate in the short term for patients with early invasive lung adenocarcinoma, the associated survival rate is similar to the lobectomy group. Segmentectomy should be considered in the treatment of early invasive lung adenocarcinoma. Meanwhile, postoperative CAR represents an independent risk factor for early postoperative recurrence in patients with IAC.

Learning curve for uniportal thoracoscopic pulmonary segmentectomy: how many procedures are required to acquire expertise?

Background

Minimally invasive surgeries are increasingly being performed. However, few studies have evaluated the learning curve for uniportal thoracoscopic segmentectomies. Therefore, we investigated the learning curve for uniportal thoracoscopic segmentectomy in our department.

Methods

We retrospectively reviewed the clinical data of consecutive patients who underwent uniportal thoracoscopic segmentectomy at our institution between February 2019 and January 2022. Two senior surgeons [Hitoshi Igai (H.I.) and Natsumi Matsuura (N.M.)] performed all of the surgeries. H.I. introduced uniportal thoracoscopic segmentectomy in our department and supervised N.M. performing this operation. Resident surgeons participated in the operations as assistants. The learning curve for uniportal thoracoscopic segmentectomy was evaluated on the basis of operative time and cumulative sum (CUSUMOT).

Results

The entire team, including resident surgeons, completed the learning curve by performing 60 surgeries. The learning curve consisted of three phases: initial learning (60 surgeries), accumulation of competence (16 surgeries), and acquisition of expertise (17 surgeries), respectively. The operative time, blood loss, postoperative drainage, and postoperative hospitalization time significantly improved across the phases. N.M. completed the initial learning curve faster than H.I. (16 and 29 surgeries, respectively).

Conclusions

Under supervision by an experienced surgeon, a team successfully completed the learning curve for uniportal thoracoscopic segmentectomy and achieved good perioperative outcomes, which indicates the importance of appropriate supervision for acquiring expertise for this surgery.

Endobronchial indocyanine green instillation to identify the intersegmental plane for successful segmentectomy

The traditional indications for lobectomy for resectable Non-small Cell Lung Cancer (NSCLC) may be set to change. Recently, anatomical segmentectomy (AS) versus lobectomy as an approach for early-stage NSCLC has been described in phase 3 randomised controlled trials. The demand for methods to facilitate AS may increase as a consequence. We describe three cases of AS using the combination of endobronchial infiltration of indocyanine green (ICG) to identify the intersegmental plane (critical for the performance of AS), and Computed Tomography (CT) guided methylene blue injection for lesion localisation. The operations were completed successfully demonstrating satisfactory post-operative outcomes including lesion resection with clear surgical margins and acceptable length of stay. We believe that endobronchial instillation of ICG and CT-guided methylene blue injection for lesion localisation show promise as a technique to complement parenchymal sparing thoracic oncological surgery.

Learning curve analysis of single-port thoracoscopic combined subsegmental resections

Background

Combined subsegmental surgery (CSS) is considered to be a safe and effective resection modality for early-stage lung cancer. However, there is a lack of a clear definition of the technical difficulty classification of this surgical case, as well as a lack of reported analyzes of the learning curve of this technically demanding surgical approach.

Methods

We performed a retrospective study of single-port thoracoscopic CSS performed by the same surgeon between April 2016 and September 2019. The combined subsegmental resections were divided into simple and complex groups according to the difference in the number of arteries or bronchi which need to be dissected. The operative time, bleeding and complications were analyzed in both groups. Learning curves were obtained using the cumulative sum (CUSUM) method and divided into different phases to assess changes in the surgical characteristics of the entire case cohort at each phase.

Results

The study included 149 cases, including 79 in the simple group and 70 in the complex group. The median operative time in the two groups was 179 min (IQR, 159-209) and 235 min (IQR, 219-247) p < 0.001, respectively. And the median postoperative drainage was 435 mL (IQR, 279-573) and 476 mL (IQR, 330-750), respectively, with significant differences in postoperative extubation time and postoperative length of stay. According to the CUSUM analysis, the learning curve for the simple group was divided by the inflection point into 3 phases: Phase I, learning phase (1st to 13th operation); Phase II, consolidation phase (14th to 27th operation), and Phase III, experience phase (28th to 79th operation), with differences in operative time, intraoperative bleeding, and length of hospital stay in each phase. The curve inflection points of the learning curve for the complex group were located in the 17th and 44th cases, with significant differences in operative time and postoperative drainage between the stages.

Conclusion

The technical difficulties of the simple group of single-port thoracoscopic CSS could be overcome after 27 cases, while the technical ability of the complex group of CSS to ensure feasible perioperative outcomes was achieved after 44 operations.

Minimally Invasive Anatomical Segmentectomy versus Lobectomy in Stage IA Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

A systematic review and meta-analysis was performed to assess potential differences in perioperative outcomes and disease-free survival (DFS) and overall survival (OS) of patients with pathological stage IA non-small cell lung cancer (NSCLC) who underwent minimally invasive anatomical segmentectomy or lobectomy.

METHODS

This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of EMBASE (through Ovid), MEDLINE (via PubMed), and Cochrane CENTRAL was conducted. Two researchers independently reviewed each eligible study that included patients with stage IA NSCLC who underwent minimally invasive anatomical segmentectomy and lobectomy and compared perioperative and/or survival outcomes of patients.

RESULTS

A total of 887 publications were identified. Of these, 10 articles met our eligibility criteria. A significantly higher number of lymph nodes were harvested in lobectomies. The two groups did not significantly differ in postoperative complication rates, DFS, and OS. Patients who underwent segmentectomy had shorter postoperative hospital stays.

CONCLUSIONS

Minimally invasive lobectomy and segmentectomy showed comparable short-term and long-term outcomes in stage IA NSCLC patients. Postoperative complication rates were similar. Minimally invasive lobectomies are associated with a higher number of harvested lymph nodes, although this did not affect the final staging or the survival outcomes.

Assessment of lymph node metastasis of ≤20 mm non-small cell lung cancer originating from superior segment compared to basal segment

BACKGROUND

Segmentectomy with curative intention is occasionally performed for early non-small cell lung cancer (NSCLC). However, a major problem has been pointed out, in that the rate of locoregional recurrence is higher after segmentectomy than after lobectomy. This study aimed to investigate differences in rates of lymph node metastasis between segment 6 and basal segment NSCLC as potential candidates for segmentectomy and to explore factors associated with locoregional recurrence of segmentectomy.

METHODS

We retrospectively analyzed 461 patients with lower lobe NSCLC who underwent segmentectomy or lobectomy with mediastinal lymph node dissection between 2011 and 2021. Among these, 122 patients with clinical N0 NSCLC, diameter ≤ 20 mm, and consolidation tumor ratio >0.5 were analyzed.

RESULTS

The 122 patients were divided into a segment 6 group (n = 51) and a basal segment group (n = 71). Frequency of lymph node metastasis was significantly higher in the segment 6 group (17.7%) than in the basal segment group (4.2%; p = 0.01). Metastases to lymph node station 7 were seen in five of 122 patients (4.1%). Hilar lymph node metastasis occurred in nine of 122 patients (7.4%). Notably, metastases to station 11, 11i and 11 s lymph nodes were the most frequent patterns for hilar lymph nodes (41.7%).

CONCLUSIONS

Station 11 lymph nodes are adjacent to the remaining lung segment or pulmonary artery in S6 segmentectomy or basal segmentectomy. Part of the NSCLC in segment 6 patients may thus be considered for lobectomy owing to the difficulty of complete dissection of station 11 lymph nodes.

"Separated" precise subsegmentectomy: Single-port thoracoscopic noncombined subsegmentectomy in one lung lobe

BACKGROUND

In clinical practice, combined segmental resection (CSS) can avoid resection of multiple segments to preserve lung function. When two or more distant lung segments or subsegments of the same lobe present with a ground glass opacity (GGO) that meets the indications for sublobar resection, conventional CSS or wedge resection could not remove all the nodules, and lobectomy is performed in most of these patients. For these particular types of nodules, we perform a single lobe noncombined subsegmental resection, or "separated" precise subsegmentectomy, to preserve more lung tissue. This study was designed to initially assess the feasibility and safety of "separated" precise subsegmentectomy.

METHODS

Selected cases of specific GGO were subjected to "separated" precise subsegmentectomy and the results of general clinical data, perioperative operative time, bleeding, length of stay, computed tomography (CT) review, lung function and its dynamic changes were collected and analyzed in these patients.

RESULTS

"Separated" precise subsegmentectomy was performed in 12 patients and successfully completed. The median operation time, bleeding amount, and length of hospital stay were 96 min, 50 ml and 4 days, respectively. There was one case of pulmonary infection and one case of persistent air leakage, no death or pulmonary torsion, bronchopleural fistula and other pulmonary complications occurred. After 3 months, the median percentage of lung function retention was 91.7%, and the CT scan showed that the reserved lung tissue of 12 patients was well inflated and there was no obvious imaging manifestation of atelectasis.

CONCLUSION

"Separated" precise subsegmentectomy is a novel and safe surgical method that provides a more optimized way for patients with specific multiple nodules to preserve lung function. Further prospective large studies are needed to verify this finding.

Microwave ablation vs. cryoablation for treatment of primary and metastatic pulmonary malignant tumors

At present, minimally invasive surgery is one of the primary strategies for the treatment of malignant pulmonary tumors. Although, there are some comparative studies between microwave ablation and radiofrequency for the treatment of malignant pulmonary tumors, there are few studies that have investigated the comparison between microwave ablation and cryoablation. The aim of the study was to retrospectively compare the efficacy and complications of microwave ablation (MWA) and cryoablation in the treatment of malignant pulmonary tumors. A retrospective analysis was performed on 48 patients with malignant lung tumors treated with MWA or cryoablation in The Third Hospital of Mianyang and The Affiliated Hospital of North Sichuan Medical College between June 2014 and June 2018. Of these patients, 29 received MWA and 19 received cryoablation. Intraprocedural pain was evaluated by using the visual analog scale (VAS). The intraprocedural pain, response rates, overall survival (OS) and complications rates were compared between the MWA group and cryoablation group. The results showed that the patients in the MWA group experienced more pain than those in cryoablation group as the MWA group VAS scores were much higher than those in cryoablation group (P<0.001). The overall response rate of the MWA group [21/29 (72.41%)] was not significantly different from the cryoablation group [14/19 (73.68%)] (P=0.92). The 6-, 12-, 24- and 36-month OS rates in the MWA group and cryoablation group were 92.72, 81.28, 64.54 and 54.91%, and 94.07, 81.13, 57.33 and 43.04%, respectively. No significant differences were found in the OS rate between the two groups (P=0.79). The complication rates in the MWA and cryoablation groups were 34.48 and 36.84%, respectively; there was no significant difference between the two groups (P=0.59). No patients died during the perioperative period. Cryoablation had a similar therapeutic effect compared with MWA in the treatment of pulmonary malignant tumors, but was associated with less pain.

"Split" combined subsegmentectomy: A case series

BACKGROUND

Clinically, some specific pulmonary nodules have safe resection margins that are located in multiple subsegments in the center of lung lobe. It is therefore difficult to ensure the resection margins through conventional combined subsegmentectomy or wedge resection, and thus lobectomy is required. For these types of pulmonary nodules, "split" operation was performed to fully inflate the reserved lung tissues on both sides. This study aimed to preliminarily assess the feasibility and safety of "split" operation.

METHODS

Cases with these types of pulmonary nodules were selected. Some of the cases were subjected to "split" operation and the operation conditions, including operation time, bleeding amount, length of hospital stay, computed tomography (CT) reexaminations, and pulmonary function, were analyzed.

RESULTS

The "split" operation was performed and successfully completed for seven patients. There was no case of conversion to thoracotomy and the median operation time, bleeding amount, and length of hospital stay were 219 min, 30.0 ml, and 4 days, respectively. No death or pulmonary complications such as pulmonary infection, lung torsion, and bronchopleural fistula occurred, and only one patient had incision fat liquefaction. After 3 months, the median percentage of preserved pulmonary function was 85.8% and a CT scan showed that the reserved lung tissues of the seven patients were well inflated and without obvious imaging findings of atelectasis.

CONCLUSION

"Split" combined subsegmentectomy can be used as a new and safe operative method for deep pulmonary nodules with safe resection margins involving multiple subsegments in the center of the lung lobe.