A recent study has found significant differences between surgical stapler technologies when it comes to the impact the devices have on the rate of air leaks, one of the most common complications associated with lobectomies, a type of thoracic surgery to treat lung cancer. The research was funded by Ethicon, part of Johnson & Johnson Medical Devices Companies, and is being announced this week at the 2019 Society of Thoracic Surgeons (STS) Annual Meeting.
 
Using a novel Physiologic Lung Model (PLM) that simulates intraoperative and postoperative breathing, researchers for the first time were able to directly observe, track and quantify staple-line air leaks from 110 sets of excised and stapled porcine lungs. Graduated staple lines, or those of varying heights, created with Medtronic’s ENDO GIA with Tri-Staple Technology (Tri-Staple) had more than twice the rate (44 percent vs. 20 percent) of staple-line air leaks under modeled physiologic breathing conditions as Ethicon’s ECHELON FLEX GST System (GST), a stapler system that surgeons use to deploy uniform closed staple line heights, according to the study published online in the peer-reviewed journal, Medical Devices: Evidence and Research in December.¹
 
In addition to finding higher air leak rates for graduated staple designs, postoperative, or natural breathing conditions, as simulated with negative pressure ventilation, were also independently associated with a higher incidence and magnitude of air leaks than positive pressure ventilation, which was used to replicate ventilator-assisted breathing conditions during surgery.
 
“Staple design and breathing modality are two important variables that may impact air leaks, one of the biggest challenges we face in thoracic surgery,” said Seth D. Force, M.D., lead study author and Chief, General Thoracic Surgery at Emory Healthcare in Atlanta, Ga. “Our findings suggest that lungs, and any associated staple lines, behave differently under intraoperative and postoperative ventilation, which may necessitate different staple design considerations and more rigorous testing of future staplers.”
 
Based on their findings, researchers hypothesize that graduated staple lines in the thinner tissue regions of the lung (outer row) do not sufficiently compress the tissue to prevent air leaks, which have been shown to occur in about one-quarter of lobectomies and are associated with longer hospitalizations, higher costs and nearly double the risk of in hospital mortality.² Differences in stapler design and how each device exerts force on tissue during stapling may also contribute to air leaks, the study authors also concluded.
 
“The evidence continues to mount that not all surgical staplers are created equally when it comes to reducing costly and serious complications associated with thoracic surgery,” said Edmund Kassis, M.D., a study co-author and Senior Medical Director for Thoracic Surgery at Ethicon. “The selection of surgical stapler could lead to better outcomes, lower costs and reduced length of stay for patients. Surgeons have an important choice to make.”
 
Another recent real-world evidence study on air leak complications adds to previous research, published in Advances in Therapy, that found Ethicon’s ECHELON FLEX Powered Staplers were associated with reduced bleeding complications, hospital costs, and length of stay in video-assisted thoracoscopic surgery (VATS) lobectomy compared to non-powered staplers manufactured by Medtronic.³ Bleeding complications, another complication associated with thoracic surgery, occur in 2 to 10 percent of procedures.^4,5
 
About the Physiologic Lung Model (PLM)
To better understand air leaks, Ethicon, in partnership with leading experts in thoracic surgery, developed a novel Physiologic Lung Model (PLM) to evaluate and quantify air leaks by incidence and volume. Unlike any previous benchtop model, the PLM approximates clinical conditions by simulating two breathing modalities in ex vivo lung tissue -- ventilated breathing and physiologic, or natural, breathing conditions, as well as enabling functional properties of the organ, such as gas exchange. No other model has the capability to simulate patients’ physiologic breathing, allowing air leaks to be examined in a simulated post-operative setting.6 The PLM was first described in “Ex Vivo Modeling of Perioperative Air Leaks in Porcine Lungs," an article that was published in the peer-reviewed journal, IEEE Transactions on Biomedical Engineering, in March 2018.  
 
References
¹ Chad E Eckert, Jason L Harris, Jordan B Wong, Suzanne Thompson, Edmund S Kassis, Masahiro Tsuboi, Harald C Ott, Seth Force. – “Preclinical quantification of air leaks in a physiologic lung model: effects of ventilation modality and staple. Medical Devices: Evidences and Research. Dec. 14, 2018; Volume 2018:11 Pages 433—442 https://www.dovepress.com/articles.php?article_id=43056
² Yoo A, Ghosh SK, Danker W. et al. Burden of air leak complications in thoracic surgery estimated using a national hospital billing database. ClinicoEconomics and Outcomes Research. 2017;9:378-383.
³ Miller DL, et al. Impact of powered and tissue-specific endoscopic stapling technology on clinical and economic outcomes of video-assisted thoracic surgery lobectomy procedures: a retrospective, observational study. In press February 13, 2018.
⁴ Kent M, et al. Open, video-assisted thoracic surgery, and robotic lobectomy: review of a national database. Ann Thorac Surg. 2014;97:236-444. 
⁵ Based on Ethicon (2016) internal analysis of data from 26,955 lobectomy procedures captured in Premier Perspective database for period 2008-2014. 
⁶ Klassen C, Eckert CE, Wong J. et al. Ex Vivo Modeling of Perioperative Air Leaks in Porcine Lungs. IEEE Transactions on Biomedical Engineering (2018). https://ieeexplore.ieee.org/document/8325303/