Bioinspired Sutureless Anastomosis Devices by 3D Printing

Vascular anastomosis, the surgical connection of adjacent blood vessels, is a foundational surgical skill critical for plastic and reconstructive surgery, transplant surgery, vascular surgery, and many other surgical specialties. The current standard of anastomosis is manually suturing two tubular structures together around an opening with fine sutures often requiring a microscope or vessel loupes. This is a century-old technique with many challenges. Suturing technique requires extensive surgical training in resource-intensive settings. Procedures are long (60 to 90 minutes per anastomosis), expensive (up to $35,000 per procedure), and, at times, require specialized equipment (surgical microscope costing over $100,000 per unit). Even in the hands of skilled surgeons, the anastomosis can be complicated by leakage or thrombosis; 27% of cases result in complications and 25% require reoperation. Consequently, there is a pressing need for a more efficient and safer alternative to a hand-sewn anastomosis. Inspired by rose prickles that are used by the plant for climbing walls, we report a sutureless anastomosis device with anchors designed to hold free vascular ends together with traction. The anchors do not penetrate the vessel wall; rather, they exert force and utilize the elasticity of the vessels to join blood vessels together with a tight seal. <br/><br/>We utilized 3D printing to find an optimum geometry of anchors by conducting <i>ex-vivo</i> tensile testing and flow measurements, as well as <i>in-vivo</i> testing with porcine models. From an anatomical standpoint, swine allows for the testing of appropriately sized devices prepared for clinical performance. We identified an optimum geometry from <i>ex-vivo</i> testing with porcine vessels, which showed the failure force of our device is comparable or better than that of the handsewn suture (4.9 N) with stretch force tolerance up to 6.3 N. Based on pulsatile flow testing with porcine vessels, we found no leakage up to 45 mL/min flow rate, well above the physiologic blood flow rate in a microvascular flap after anastomosis (13.7±5 mL/min). Compared with hand-sewn anastomosis, the device resulted in minimum deformation of the anastomotic site. From <i>in-vivo</i> non-survival porcine studies (N=10), the device showed successful anastomosis (&lt; 5 min per anastomosis) with no leaking for both arterial and venous anastomoses, with an average flow gradient of 0.99±0.31 across the device. There was no thrombosis or other technical failure identified during the 4-hour observation period after device implantation. Our anastomotic device has the ability to innovate the way blood vessels are put together making current procedures safer for patients. In addition, our sutureless anastomotic device will make current anastomotic techniques more accessible to a broad range of clinicians, researchers, and patients across the world. <br/><br/><b>ACKNOWLEDGEMENTS</b><br/>The research is supported by Maryland Innovation Initiative, Cohen Translational Engineering Fund, Bisciotti Foundation Translational Grant, and Johns Hopkins University Start-Up Fund.