Uniportal video-assisted thoracoscopic surgery simple versus complex segmentectomy: a retrospective comparative study on mid-term surgical and early oncological outcomes

Introduction

Recent randomized trials, including the JCOG0802/WJOG4607L trial and CALGB 140503 trial, have established pulmonary segmentectomy as an effective alternative to lobectomy for patients with peripheral non-small cell lung cancer (NSCLC) with tumor size ≤2 cm and pathologically confirmed node-negative disease (1,2). With advances in minimally invasive surgery, uniportal video-assisted thoracoscopic surgery (VATS) segmentectomy has earned widespread adoption, providing benefits such as reduced postoperative pain, shorter hospital stays, and lower morbidity when compared to multiportal VATS or thoracotomy (3,4).

Segmentectomy procedures are categorized as either simple or complex, depending on how many intersegmental planes need to be divided. Simple segmentectomy includes procedures such as superior segmentectomy, upper division segmentectomy, and lingular segmentectomy, whereas complex segmentectomy involves creating multiple intersegmental planes, thereby making the procedure technically more demanding (5). Despite its technical complexity, complex segmentectomy is increasingly performed due to its potential oncological and functional advantages (5). However, comparative data on surgical and early oncological outcomes between simple and complex segmentectomy, especially in the uniportal VATS setting, remain limited.

At our institution, complex segmentectomy has been performed more frequently than simple segmentectomy, with an increasing annual trend. While previous studies have confirmed its safety and feasibility regarding perioperative and surgical outcomes, early oncological outcomes, particularly recurrence-free survival, require further investigation (6).

This study aims to compare mid-term surgical outcomes, perioperative results, and early oncological outcomes between uniportal VATS simple and complex segmentectomy. By analyzing clinical, pathological, and survival data, this study sought to determine whether uniportal VATS complex segmentectomy represents a safe and oncologically viable alternative to simple segmentectomy. We present this article in accordance with the STROBE reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-573/rc).

Methods

Patient population

This study retrospectively evaluated 1,157 patients who underwent uniportal VATS for primary lung cancer, all of whom were operated on by a single surgeon at a single institution between May 2019 and December 2024. After excluding 644 patients who underwent uniportal VATS wedge resection, lobectomy, bilobectomy, or pneumonectomy, a total of 513 patients were included in the study. Of the patients included in the analysis, 135 underwent a simple segmentectomy, 355 received a complex segmentectomy, and 23 were treated with a basal segmentectomy—each procedure conducted via a uniportal VATS approach and achieving complete microscopic resection (R0). In our study, basal segmentectomy was defined as a third distinct category. Although technically categorized as a simple segmentectomy due to involving the division of a single intersegmental plane, basal segmentectomy was analyzed separately because of its distinct procedural complexity. A flowchart illustrating the study design is presented in Figure 1. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study protocol was approved by the Institutional Review Board of the Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea (No. PC24RASI0186), which did not require individual consent for this retrospective study.

Figure 1 Flow chart illustrating the study design.

Institutional strategy for segmentectomy

At our institution, segmentectomy is routinely selected for patients with peripheral NSCLC who satisfy specific surgical criteria, such as having tumors ≤2 cm in diameter and no radiologic or pathologic evidence of nodal metastasis. Surgical planning is focused on securing a sufficient resection margin—either at least 2 cm or a distance equal to the tumor size as measured on preoperative imaging. The decision to perform simple or complex segmentectomy is primarily guided by the tumor’s anatomical location and the feasibility of achieving this margin. Before initiating the segmentectomy, palpable lesions are marked using a marking pen assisted by a curved suction tip. When performing complex segmentectomy, if the anticipated margin appears insufficient with resection of a single segment, we consider extending the resection to include adjacent subsegments or segments, based on tumor location, to ensure adequate oncological clearance. If the lesion was not palpable, intraoperative CT review was performed, and palpation was reassessed after segment retrieval, assuming the lesion would be located within the resected segment.

To delineate the intersegmental plane, we utilized systemic indocyanine green injection along with scopes of varying specifications. For tumors presenting as pure ground-glass opacity (GGO) or part-solid GGO, a lobe-specific lymphadenectomy was performed. In contrast, patients with part-solid or solid tumors demonstrating a standardized uptake value (SUV) exceeding 3.0 on fluorodeoxyglucose positron emission tomography (FDG-PET/CT) underwent systematic lymph node dissection. To rule out nodal involvement at the N1 level, intraoperative frozen section analysis was routinely utilized.

Post-surgical management included chest tube placement connected to a digital drainage system (Thopaz; Medela Healthcare, Baar, Switzerland), initially set to −15 cmH₂O. On the first postoperative day, the suction was reduced to −7 cmH₂O and maintained until tube removal. Removal criteria included no air leak for at least 12 hours and daily drainage below 200 mL. Discharge was typically arranged following chest tube removal and pathology confirmation, though timing was adjusted based on patient preference and practical considerations such as distance from the hospital.

Early oncological outcome

For the subgroup analysis, we identified 190 patients who underwent segmentectomy and were followed with chest computed tomography (CT) for a minimum of two years postoperatively. Of these, eight patients were excluded: three due to pathologically confirmed lymph node metastasis (pN1/pN2) who subsequently received adjuvant chemotherapy, one due to recurrence of contralateral lung cancer, one who was diagnosed with malignant melanoma and later died from another cancer-related cause, and two who were lost to follow-up. The final cohort for recurrence-free survival analysis thus included 182 patients with complete 2-year follow-up, in addition to one patient who experienced recurrence at 5 months postoperatively.

Statistical analysis

All statistical analyses were performed using R (R Foundation for Statistical Computing, Vienna, Austria) with statistical modeling assisted by ChatGPT (OpenAI, San Francisco, CA, USA). Continuous variables were expressed as means with ranges, while categorical variables were presented as numbers with percentages. Fisher’s exact test or Pearson’s Chi-squared test was used to compare categorical variables between simple and complex segmentectomy groups, whereas the Wilcoxon rank sum test was applied to continuous variables. Operative and postoperative outcomes, including hospital stay, postoperative bleeding, and recurrence rates, were evaluated using appropriate statistical techniques. Comparisons between groups were conducted for operative time, estimated blood loss, duration of chest tube drainage, and length of hospital stay. Recurrence analyses were stratified according to tumor differentiation, consolidation to tumor ratio (C/T ratio), and surgical margin distance. A P value of less than 0.05 was considered statistically significant.

Results

A total of 513 patients underwent uniportal VATS segmentectomy, including 135 simple segmentectomies, 355 complex segmentectomies, and 23 basal segmentectomies (Figure 1). Our institution has performed more complex than simple segmentectomies, with a progressive annual increase in the volume of segmentectomies overall (Figure 2).

Figure 2 Uniportal VATS simple, complex, and basal segmentectomies performed at our institution between 2019 and 2024. VATS, video-assisted thoracoscopic surgery.

In uniportal VATS simple segmentectomy, the most frequently resected segment was S6 (superior segment), accounting for 57.0% of the 135 patients, followed by S1+2+3 (upper division segment) in 25.9%, and S4+5 (lingular segment) in 17.0%. Conversely, in uniportal VATS complex segmentectomy, the most commonly resected segment was S1+2 (apico-posterior segment) in 19.2% of the 355 patients, followed by S3 (anterior segment) in 17.5%, and S1 (apical segment) in 16.1%. Among lower lobe segmentectomies, the segment most frequently resected was S8 (antero-basal segment) in 9.0% of the 355 patients, followed by S10 (postero-basal segment) in 5.1%. These findings are detailed in Tables 1,2.

The demographic characteristics, baseline patient characteristics, and tumor characteristics are summarized in Table 3. The study included 135 patients (46 men and 89 women) who underwent uniportal VATS simple segmentectomy, with a mean age of 56.6±13 years. Meanwhile, 355 patients (116 men and 239 women) underwent uniportal VATS complex segmentectomy, with a mean age of 56.9±11.2 years. Among those who underwent uniportal VATS simple segmentectomy, 45 patients (33.3%) had a smoking history (current or former), compared to 104 patients (29.3%) in the uniportal VATS complex segmentectomy group. There were no statistically significant differences between the two groups regarding age, sex, smoking history, or previous malignancy. Histologically, most tumors in both groups were adenocarcinomas. In the uniportal VATS simple segmentectomy group, 131 patients (97.0%) had adenocarcinoma, 2 patients (1.5%) had squamous cell carcinoma, and 2 patients (1.5%) had other histologic types, including mixed adenocarcinoma and small cell lung cancer. Similarly, in the uniportal VATS complex segmentectomy group, 351 patients (98.9%) had adenocarcinoma, 1 patient (0.3%) had squamous cell carcinoma, and 3 patients (0.8%) had other histologic types, including small cell lung cancer, typical carcinoid, and large cell neuroendocrine carcinoma. The most common adenocarcinoma subtype was invasive adenocarcinoma, observed in 93 patients (69.9%) in the uniportal VATS simple segmentectomy group and 242 patients (68.8%) in the uniportal VATS complex segmentectomy group. There were no significant differences between the two groups regarding tumor histology, size on CT, C/T ratio, adenocarcinoma subtypes, or tumor differentiation grade.

Table 4 presents the operative outcomes for both simple and complex segmentectomy performed via uniportal VATS. The mean anesthesia and operation times for simple segmentectomy were 128.8±37.5 and 98.4±34.8 minutes, respectively, while those for complex segmentectomy were 130.2±36.5 and 102.5±34.1 minutes, respectively. The mean estimated blood loss for simple segmentectomy was 63.3±112.8 mL, whereas that for complex segmentectomy was 54±38.7 mL. No significant difference in surgical margin distance was observed between the two groups (P=0.86), with the simple segmentectomy group having a mean distance of 24±11 mm and the complex segmentectomy group having a mean distance of 24±10 mm. Within the simple segmentectomy group, a single case involving an upper division segment required conversion to thoracotomy due to intraoperative bleeding caused by vessel injury at the junction of the left main pulmonary artery and the apico-posterior segmental branch. Despite this event, no statistically significant differences were observed between the simple and complex groups in terms of anesthesia duration, operative time, blood loss, use of indocyanine green, conversion rates, or pleural adhesion status.

Postoperative outcomes for both uniportal VATS simple and complex segmentectomies are detailed in Table 5. The average duration of chest tube drainage was 1.8±2.3 days for the simple group and 1.5±1.4 days for the complex group. A significant difference was observed in the duration of postoperative hospital stay between the two groups (P=0.04), with a mean stay of 6.8±4.0 days for the simple segmentectomy group and 6.0±2.8 days for the complex segmentectomy group. A total of 21 postoperative complications were reported, including prolonged air leak, chylothorax, pneumothorax, pneumonia, transient ischemic attack, fever, bleeding, and myocardial infarction. Notably, three patients in the simple segmentectomy group experienced postoperative bleeding, whereas no bleeding occurred after complex segmentectomy (P=0.02).

In the subgroup analysis, the final study population consisted of 182 patients who completed at least 2 years of postoperative surveillance, along with one additional recurrence that occurred 5 months postoperatively. Among these, one recurrence was observed in the complex segmentectomy group, while another was found in the basal segmentectomy group. Figure 3 illustrates the Kaplan-Meier survival curves depicting the 2-year recurrence-free survival of patients undergoing uniportal VATS segmentectomy, stratified by segmentectomy type. Simple segmentectomy is shown in green, complex segmentectomy in orange, and basal segmentectomy in blue.

Figure 3 Kaplan-Meier curves demonstrating 2-year recurrence-free survival stratified by segmentectomy type, with numbers at risk provided at 10-month intervals.

The two recurrent cases were both adenocarcinomas with moderate differentiation and exhibited a C/T ratio ≥0.5 despite achieving adequate surgical margins of 1.2 and 3.3 cm.

Discussion

Our study assessed the mid-term surgical outcomes of uniportal VATS simple and complex segmentectomy, along with early oncological outcomes, based on the type of segmentectomy performed in patients with early-stage NSCLC. Our findings suggest that the safety, perioperative characteristics, and short-term recurrence rates of complex segmentectomy are on par with those of simple segmentectomy.

Complex segmentectomy of the lower lobes presents significant challenges due to the deep localization of vascular structures and bronchi within the lung parenchyma, as well as the high prevalence of anatomical variations that increase the risk of misidentification during surgery (5,7). Despite these complexities, our data suggest that complex segmentectomy can be safely and effectively performed using a uniportal VATS approach. In our study, 90 out of 355 patients (25.7%) underwent complex segmentectomy of the lower lobe, and none required conversion to lobectomy or extended resection due to inadvertent misidentification of segmental vascular structures or bronchi. Operative time, estimated blood loss, and thoracotomy conversion rates were comparable between the simple and complex segmentectomy groups, aligning with findings from previous studies. Interestingly, simple segmentectomy was associated with a slightly longer hospital stay and higher postoperative bleeding rates, a finding that contrasts with the expectation that it would be technically simpler than complex segmentectomy.

The early oncological outcomes observed in our study are particularly noteworthy, with only two cases of recurrence identified since 2019. Among the 513 patients who underwent segmentectomy, 190 underwent postoperative surveillance with chest CT for at least 2 years. Eight patients were excluded for various reasons, including three with lymph node metastasis (pN1/pN2) who received adjuvant chemotherapy, one patient with contralateral lung cancer recurrence, one patient diagnosed with malignant melanoma who later died due to another cancer-related cause, and two patients lost to follow-up. The final study population consisted of 182 patients who completed at least 2 years of postoperative surveillance, along with one additional recurrence identified 5 months postoperatively.

The JCOG0802/WJOG4607L trial reported a 5-year relapse-free survival rate of 88.0% in the segmentectomy group and 87.9% in the lobectomy group. Postoperative recurrence occurred in 10.5% of patients who underwent segmentectomy, compared to 5.4% in the lobectomy group (1). Similarly, a multicenter propensity score-matched analysis by Handa et al. reported comparable long-term outcomes between complex segmentectomy and lobectomy, with a 5-year recurrence-free interval (RFI) rate of 95.5% for complex segmentectomy versus 95.9% for lobectomy (5). Although direct comparisons are limited due to differences in follow-up duration, our study revealed 2-year RFI rates of 100% for simple segmentectomy, 98.4% for complex segmentectomy, and 80% for basal segmentectomy. The relatively lower 2-year RFI rate observed for basal segmentectomy likely reflects the small sample size. Specifically, between May 2019 and May 2021, only five basal segmentectomies were performed, limiting the statistical power of this subgroup analysis. However, when comparing the simple and complex segmentectomy groups alone, no significant difference in the 2-year RFI rates was observed, further supporting the oncological equivalence of these procedures.

Among the five patients who underwent basal segmentectomy during this period, recurrence occurred in one patient at 21 months postoperatively. The pathologic staging was pT1bN0M0, with a tumor size of 1.3 cm and an invasive size of 1.3 cm. The resection margin was 1.2 cm. The tumor was moderately differentiated, exhibiting an acinar component (85%), a micropapillary component (10%), and a solid component (5%). PET-CT revealed an SUVmax of 2.33, and the lesion was classified as a part-solid ground glass nodule. Following completion lobectomy, the final pathologic stage was pT2aN2M1a with pleural metastasis.

Upon retrospective review, the tumor was located in the inner two-thirds of the lung, and the resection margin was relatively narrow at 1.2 cm. Recently, a study reported that for clinical stage 0 to stage 1A NSCLC, tumor location in the inner two-thirds of the lung was not significantly associated with prognosis following segmentectomy (8). The preoperative chest CT revealed a part-solid ground glass nodule with a solid portion measuring 9 mm. However, the final pathology confirmed the tumor as stage 1A2 NSCLC, suggesting that radiologic findings may not always accurately reflect the invasive extent of early-stage lung cancer. These findings highlight the need for more stringent selection criteria for segmentectomy, particularly in patients with tumors located in the inner two-thirds of the lung, where achieving an adequate resection margin may be challenging. Careful preoperative planning and margin assessment are essential to minimize the risk of recurrence in such cases.

In the complex segmentectomy group, one patient experienced recurrence 5 months postoperatively following apico-posterior segmentectomy (S1+2). The pathologic stage was pT2aN0M0, with a tumor size of 2.0 cm and an invasive component of 2.0 cm. The resection margin was 3.3 cm, and the tumor exhibited a high SUVmax of 5.3 on PET-CT. Histologically, it was moderately differentiated and classified as a pure solid lesion, with an acinar component of 30%, a papillary component comprising 60%, and a micropapillary component comprising 10%. The patient subsequently underwent wedge resections and was diagnosed with pulmonary metastases in the right middle lobe, leading to a final stage of pT4.

Upon retrospective review, the patient had undergone bilateral segmentectomies due to synchronous multiple primary lung cancers. Despite the high SUVmax on PET-CT, segmentectomies (left lower basal segmentectomy and right apico-posterior segmentectomy) were the only viable option due to the patient’s limited pulmonary function. The management of hypermetabolic tumors remains challenging, as recent studies suggest that lobectomy may yield better long-term outcomes (9). Brunelli and colleagues reported that patients with hypermetabolic tumors had superior 4-year overall survival after lobectomy compared to segmentectomy [lobectomy: 87%; 95% confidence interval (CI): 76–93% vs. segmentectomy: 67%; 95% CI: 49–80%; P=0.03]. Additionally, a trend favoring lobectomy was observed in 4-year event-free survival (lobectomy: 77%; 95% CI: 65–85% vs. segmentectomy: 58%; 95% CI: 39–72%; P=0.09) (9). Furthermore, the tumor was a solid lesion, which is notable since previous studies have reported that most patients who experience loco-regional relapse after segmentectomy present with solid-dominant tumors (10). Nevertheless, surgical decision-making in patients with synchronous multiple primary lung cancers remains complex. Another study reported that prognosis is primarily determined by the status of the dominant tumor, with no statistically significant difference in survival between sublobar resection and lobectomy (11,12). Furthermore, sublobar resection has been associated with a safer perioperative course compared to lobectomy, making it a reasonable option for patients with compromised pulmonary function (11). These findings underscore the ongoing challenges in selecting the optimal surgical strategy for patients with multiple primary lung cancers. While lobectomy may offer better long-term outcomes for hypermetabolic tumors, sublobar resection remains a viable alternative for patients with limited pulmonary reserve. Balancing oncological efficacy with functional preservation continues to be a key challenge in thoracic surgical decision-making.

In our previous study, we concluded that the median surgical margin distance for complex segmentectomy [20 mm (interquartile range, 15–26 mm)] was shorter than that for simple segmentectomy [22 mm (interquartile range, 17–32 mm)] (6). These findings, similar to those reported by Okubo et al., suggest that surgeons should pay close attention to achieving adequate surgical margins during complex segmentectomy to minimize the risk of recurrence (13). However, in our mid-term operative outcomes, no statistically significant difference in surgical margin distance was observed between the simple (24±11 mm) and complex (24±10 mm) segmentectomy groups.

The increasing adoption of complex segmentectomy reflects an evolving surgical trend favoring more lung-preserving approaches without compromising oncological outcomes. Our study supports the use of uniportal VATS for complex segmentectomy, providing evidence that minimally invasive approaches can achieve oncological efficacy while maximizing lung preservation.

This study had several limitations. First, the retrospective design introduced potential selection bias. Second, the follow-up duration was limited to 2 years, preventing an assessment of long-term survival. Third, molecular and genetic characteristics of tumors were not assessed, which could have further elucidated recurrence patterns. Additional studies with larger cohorts, longer follow-up durations, and molecular analyses are necessary to validate these findings.

Conclusions

Our results support the notion that uniportal VATS complex segmentectomy is a safe option with outcomes equivalent to those seen in simple segmentectomy, at least in the mid-term follow-up. The low recurrence rate observed supports its viability as a surgical option. Additional studies with extended follow-up are necessary to confirm these findings and evaluate long-term oncological outcomes.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-573/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-573/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-573/prf

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-573/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study protocol was approved by the Institutional Review Board of the Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea (No. PC24RASI0186), which did not require individual consent for this retrospective study.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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