Outcome comparison between two staplers used for pulmonary resection: a retrospective cohort study

Introduction

The advent of surgical staplers has significantly transformed the landscape of lung resection surgery (1). These innovative devices have replaced traditional hand-suturing techniques, offering a multitude of benefits that have revolutionized the field. By enabling faster and more precise closure of tissues, surgical staplers have reduced operative times, minimized blood loss, decreased rate of postoperative air leak and improved overall surgical outcomes for patients undergoing lung resections (2). There have been two main stapler brands for the past three decades: Signia™ (Covidien, Medtronic Inc., Minneapolis, MN, USA) and Ethicon (Johnson & Johnson, New Brunswick, NJ, USA). A new surgical stapler company, Lexington Medical, gained Food and Drug Administration (FDA) approval in November 2017 for their AEON™ (Lexington Medical Inc., Billerica, MA, USA) endoscopic Stapler. This retrospective study compares the AEON and Signia staplers, for patients who underwent video-assisted thoracoscopic surgery (VATS) lung wedge resection. The AEON stapler (Figure 1) has been developed with a uniform staple height and a simplified mechanical design intended to provide consistent tissue compression. To our knowledge, no prior comparative study has evaluated AEON versus Signia (Figure 2) staplers in thoracic VATS wedge resections, highlighting the novelty of this research. We present this article in accordance with the STROBE reporting checklist (available at https://vats.amegroups.com/article/view/10.21037/vats-25-31/rc).

Figure 1 The AEON™ endoscopic linear stapler (this figure was reused with permission from Lexington Medical Inc., Billerica, MA, USA).

Figure 2 Signia™ endoscopic linear stapler (this figure was reused with permission from Medtronic, Minneapolis, MN, USA).

Methods

This retrospective cohort study included patients who underwent VATS lung resection at Mayo Clinic Florida between 2018 and 2024. Signia was the predominant stapler we used between 2018 and 2021. AEON was the predominant stapler between 2021 and 2024. Patients were divided into two groups based on the type of stapler used.

We chose to focus on VATS wedge resections because there are less variables involved with this surgery than with anatomic resections. Exclusion criteria also included redo thoracic procedures and severe preoperative dysfunction, in addition to open and robotic approaches, lung volume reduction surgery (LVRS), or bleb/air leak surgeries. All procedures were performed by two board-certified thoracic surgeons using a standardized VATS wedge resection protocol. Staplers were applied according to each manufacturer’s recommended technique.

Data collected included demographic information, preoperative pulmonary function test parameters, length of stay (LOS), total number of stapler’s loads used in each case, and postoperative outcomes. A prolonged air leak was defined as more than 5 days. Reintervention was defined as any procedure performed on the patient in the post-operative period including bronchoscopy or re-insertion of a chest tube. Reoperation was defined as a return to the operating room. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Mayo Clinic Institutional Review Board, Jacksonville, Florida, USA (IRB#24-002593), and individual patient consent was waived, given the retrospective nature of the study.

Statistical analysis

Continuous variables were compared using t-tests, and categorical variables were analysed using Chi-squared tests. The median values for LOS and the number of loads used were compared using the Mann-Whitney U test. SPSS software used to conduct the analysis. All statistical analyses were two-sided, and significance was set at a P value of <0.05. In addition, multivariate regression analysis was performed to adjust for univariates’ significant results.

Results

Demographic characteristics

A total of 79 patients were included in the study, with 43.0% in the AEON™ stapler group and 57.0% in the Signia™ stapler group. The median age was non-significant between the two groups with 65.5 years for AEON and 67 years for Signia (P=0.96). There was, however, a significantly higher proportion of female patients in the AEON group (82.4%) compared with the Signia group (55.6%) (P=0.02). Race distribution was similar, with 85.3% White in AEON and 88.9% in Signia (P=0.74). Smoking history was comparable, with 52.9% of AEON patients and 53.3% of Signia patients identified as ever-smokers (P>0.82). Preoperative pulmonary function was also comparable, with mean forced expiratory volume in 1 second (FEV1)% of 88.6% in AEON vs. 89.9% in Signia (P=0.44), diffusion capacity of the lungs for carbon monoxide (DLCO)% of 83% vs. 79% (P=0.82), and RV% of 130.8% vs. 113.6% (P=0.14).

Pathologic indications for resection differed between groups. AEON patients were more likely to undergo resection for primary lung cancer (61.8% vs. 33.3%, P=0.02), whereas Signia patients more frequently had metastatic disease (20.6% vs. 46.7%, P=0.02). Benign disease accounted for 8.9% of AEON cases and 15.6% of Signia cases (P=0.50), while nondiagnostic biopsy accounted for 5.9% in AEON and 4.4% in Signia (P>0.99). Lymphoma was present in 3.0% of AEON patients and in none of the Signia patients (P=0.43). These distributions are summarized in Table 1.

Postoperative outcomes

Postoperative complications and perioperative outcomes are presented in Table 2. No significant differences were observed between AEON and Signia in terms of prolonged air leak (0% vs. 0%, P>0.99), bleeding requiring reintervention (0% vs. 0%, P>0.99), pneumothorax (0% vs. 0%, P>0.99), reintervention (0% vs. 2.2%, P>0.99), reoperation (0% vs. 0%, P>0.99), or readmission (0% vs. 0%, P>0.99).

Median LOS was 1 day (IQR 1–2) for AEON patients compared with 2 days (IQR, 1–2) for Signia patients (P=0.08). Because LOS was a discrete, right-skewed count variable (median 1 day, IQR, 1–2, skewness 1.36), a Poisson regression model was used. In the multivariable model adjusting for sex and pathology subtype, stapler type was not independently associated with LOS (Signia vs. AEON: P=0.16). Neither sex (P=0.52) nor any pathology subtype (biopsy P=0.51; metastatic disease P=0.94; primary lung cancer P=0.44; lymphoma P=0.48) showed a significant association with LOS. The median number of stapler’s loads used per case was 4 (IQR, 3–5) for AEON and 3 (IQR, 2–5) for Signia (P=0.39).

Discussion

Since the initial successful application of stapling devices for lung surgery in the Soviet Union during the 1950s and subsequently in the United States during the 1960s, advancements in endoscopic instruments have significantly evolved (3). These innovations now facilitate precise, safe, and efficient transection of lung tissue while simultaneously ensuring effective sealing. Prior to the advent of stapling devices, lung clamping and suturing were the only techniques available for managing lung tissue during surgery (1).

Staplers provide consistent tissue compression and thus reduce air leaks. Air leaks are an important complication after lung resection because they increase morbidity, prolong the LOS, and increase cost (4-6).

For example, a non-blinded randomized controlled trial was conducted comparing hand-sewn versus stapler division and closure of incomplete fissures during lobectomy. The results demonstrated that the incidence of postoperative air leaks was significantly lower in the stapler group compared to the hand-sewn group (7.7% vs. 29.6%, P=0.044). Additionally, the duration of air leaks was markedly shorter in the stapler group (1.0 vs. 13.4 days, P=0.03) (7).

We decided to retrospectively review our data, to ensure our results remained consistent with the change in stapler.

The AEON stapler has been shown to be safe and effective in other surgical areas such as bowel anastomoses and pancreatic resections (8-10). The AEON stapler has been examined in thoracic procedures before. Dutly et al. (11) reported their experience in an abstract using the AEON Endostapler in a retrospective, non-comparision series with 80 patients and 454 reloads. They concluded that the AEON™ stapler appears to be safe in general thoracic cases and presents a cost-effective option. Unlike prior descriptive reports, this study directly compares AEON with an established powered stapler in thoracic surgery, addressing a gap in the literature and providing clinically relevant data on their relative performance.

Limitations

Retrospective studies include selection bias. We believe this bias was mitigated in this study because we switched stapler brands in early 2021 and remained consistent with that brand throughout the course of this study. In other words, we did not select one stapler over another for a particular patient. This sequential use of one stapler brand after the other could introduce a learning bias. This bias should be small because the two surgeons performing the procedures both had greater than 4 years of post-residency practice before the start of this study. Therefore, we believe there would have been minimal increase in learning or proficiency over those 6 years.

Additionally, chronological grouping by time period may have introduced bias related to changes in surgical techniques or perioperative protocols, including the impact of the coronavirus disease 2019 (COVID-19) pandemic, which should be considered when interpreting the findings.

Other limitations include the small single-center sample size, which reduces statistical power and may overestimate effect sizes. A post hoc power calculation demonstrated that detecting a 20% difference in prolonged air leak would require ~100 patients for 80% power, indicating our study may be underpowered for small differences. In addition, differences in baseline sex distribution and pathology types between stapler groups represent potential confounders; while adjusted analyses were performed, these imbalances should be considered when interpreting the findings. Finally, although smoking status was balanced across groups, other unmeasured variables may also have influenced outcomes.

Conclusions

This study demonstrated that both the AEON™ stapler and the Signia™ stapler are safe and effective options for pulmonary resections. Both staplers are suitable for use in thoracic surgery, and the choice of device should be guided by surgeon experience, patient factors, and cost considerations. Larger studies are necessary to confirm these findings and to explore potential advantages of one stapler over the other in specific patient populations.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://vats.amegroups.com/article/view/10.21037/vats-25-31/rc

Data Sharing Statement: Available at https://vats.amegroups.com/article/view/10.21037/vats-25-31/dss

Peer Review File: Available at https://vats.amegroups.com/article/view/10.21037/vats-25-31/prf

Funding: This work was supported by Lexington Medical Inc., Billerica, MA, USA to M.A.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://vats.amegroups.com/article/view/10.21037/vats-25-31/coif). M.A. received a grant from Lexington Medical to carry out this research. The collection of data, analysis, and writing of this manuscript were performed without any input or approval from the sponsor. The other 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 was approved by the Mayo Clinic Institutional Review Board, Jacksonville, Florida, USA (IRB#24-002593), and individual patient consent was waived given the retrospective nature of the 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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