Uniform Stapling Helps Reduce Thoracic Surgery Air Leak

Researchers at Emory Healthcare (Atlanta, GA, USA), Massachusetts General Hospital (Boston, USA), Ethicon Endo-Surgery (Ethicon; Cincinnati, OH, USA), and other institutions, used a novel physiologic lung model (PLM) that simulates intraoperative and postoperative breathing in order to directly observe, track, and quantify staple-line air leaks from 110 sets of excised and stapled porcine lungs. Air leaks associated with graduated and uniform staple designs were evaluated under positive and negative pressure ventilation, simulating perioperative breathing.

Air leak incidence, air leak volume, and air leak rate were captured, along with ventilation pressure and tidal volume. The results revealed that in all cases, negative pressure ventilation was associated with a higher occurrence of leaks, when compared to positive pressure ventilation. Graduated staple designs were associated with higher occurrence of leaks as well as larger leak rates when compared to uniform staples. Tissue thickness, on the other hand, was not associated with differences in air leaks when tested with appropriate staple heights.

Based on their findings, the researchers hypothesize that graduated staple lines in the thinner tissue regions of the lung 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. Differences in stapler design and how each device exerts force on tissue during stapling may also contribute to air leaks. The study was presented at the Society of Thoracic Surgeons (STS) annual meeting, held during January 2019 in San Diego (CA, USA).

“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 senior author and study presenter Seth Force, MD, chief of general thoracic surgery at Emory Healthcare. “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.”

Tissue movement or slippage during staple firing can result in poorly formed and spaced staples, as well as the need for extra firings to complete tissue transection. In addition, mechanical or ischemic issues, either technical, operator, or patient-related, can predispose to leakage, such as stapler misfiring, direct tissue injuries, tissue creep, tensile stress relaxation, and shear stress.

Related Links:
Emory Healthcare
Massachusetts General Hospital
Ethicon Endo-Surgery