Towards Preventing Anastomotic Leakage through the “No-perforation Virtual Staples”
Authors: Nie Jiabao , Liu Fan , Ali Ali Basil , Khalil Hassan A , Mentzer Steven J , Chen Zi 
Published: May 2024

Anastomotic leakage (AL) is a severe postoperative complication after gastrointestinal surgery, potentially leading to morbidity and mortality. The factors contributing to AL include poor blood flow to the suture line, tension, infection, underlying conditions, and surgeon-related factors. However, the stress concentration, which is a localized increase in stress due to discontinuities caused by sutures or staples, has often been overlooked. The working hypothesis is that by removing problematic stresses and simulating mechanical loadings on the anastomosis, improved recommendations for stapler design, surgical technique, and anastomotic construction can be derived to reduce the occurrence of leaks. The objective of this study is to develop and optimize "no-perforation" magnetic staples that can effectively minimize stress and prevent AL. In this study, magnet-metal bar couples coated with a biocompatible adhesive hydrogel were utilized to replace existing surgical staples. By employing magnetic forces, the tissue was deformed into a curved shape, which provided additional security for the new "magnetic staples". This technique aimed to eliminate complications such as high tension and poor blood flow often associated with traditional staples. To ensure safety, a double protection system consisting of the pectin adhesive (previously patented at BWH) and the "lock-in forces" of the magnetic staples was implemented. It was believed that relying solely on adhesion would not effectively prevent leaks. Preliminary data indicated that applying virtual staples for anastomoses was feasible. The primary innovation of this approach is the substantial reduction in stress concentration when the anastomosis is under tension. The conventional surgical teaching concerning bowel anastomoses has centered on the dangers posed by excessive tension and compromised blood supply. In contrast, virtual staples offer the advantage of adjustable shape and force, allowing for optimization of tension and blood supply. The study successfully identified the biomechanical forces and stress concentrations that contribute to anastomotic leaks and developed new "virtual staples" to address this issue. The new "virtual staples" are made of two magnetic compression rings crafted from medical-grade silicone and feature 8 strategically embedded magnets. These rings are engineered with a specific surface curvature to ensure optimal axial alignment and elimination of stress concentrations. Cases for delivery have also been designed and fabricated, which are compatible with standard commercial delivery devices used in surgical settings. This ensures a seamless integration into existing medical procedures and surgical workflows. Initial in-vitro experiments were conducted on sections of the porcine intestine to test the effectiveness of the Virtual Staples. These preliminary tests have shown promising results, including an absence of leakage at the joined or sealed tissue sites. Our research aims to predict the stress concentration sites in tissues and evaluate the effects of applying adhesive virtual staples under new conditions. Through a combination of experiments and simulations, we designed non-perforation staples and optimized the design by considering various factors such as staple size, shape, magnet strength, and stress distribution. Initial in-vitro experiments indicated the effectiveness of the design. With further optimization of the design, along with animal testing and clinical trials, this new technique has the potential to revolutionize surgical procedures. The MA Acorn Innovation Grant 2023. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.