A systematic review of sutureless vascular anastomosis technologies

Non-Thermal Atmospheric Pressure Plasma as an Adjunct to Intestinal Anastomosis: A Pilot Study on Preventing Anastomotic Leaks

Anastomotic leaks remain a significant challenge in intestinal surgery, often leading to severe complications. This study investigated a novel approach to enhance anastomotic healing and reduce the risk of leaks by combining traditional suturing and stapling techniques with non-thermal atmospheric pressure plasma (NTAPP) application. NTAPP, a cold atmospheric plasma generated through the ionization of ambient air, has been shown to possess antimicrobial, hemostatic, and wound-healing properties. NTAPP promotes sterilization, coagulation, and tissue regeneration by generating reactive oxygen and nitrogen species, potentially strengthening anastomotic union. This pilot study evaluated the efficacy of NTAPP in three patients undergoing intestinal anastomosis. Following the standard surgical procedure, NTAPP was applied directly to the anastomotic site. Postoperative outcomes were monitored for six months, including anastomotic leaks and healing rates. Preliminary results demonstrated promising outcomes. All three patients exhibited successful sealing of the anastomosis, with no evidence of leakage during the follow-up period, providing reassurance and confidence in the potential of sutures, staples, and NTAPP. These findings suggest that NTAPP can significantly improve the safety and efficacy of intestinal surgeries by reducing the incidence of anastomotic leaks. While further research with a larger sample is necessary to confirm these initial findings, the results of this study provide a strong foundation for exploring the potential of NTAPP as a valuable adjunct to conventional surgical techniques for preventing anastomotic leaks. This innovative approach could reduce postoperative complications, improve patient outcomes, and enhance the overall quality of care in intestinal surgery.

Sutureless vascular anastomotic approaches and their potential impacts

Sutureless anastomotic devices present several advantages over traditional suture anastomosis, including expanded global access to microvascular surgery, shorter operation and ischemic times, and reduced costs. However, their adaptation for arterial use remains a challenge. This review aims to provide a comprehensive overview of sutureless anastomotic approaches that are either FDA-approved or under investigation. These approaches include extraluminal couplers, intraluminal devices, and methods assisted by lasers or vacuums, with a particular emphasis on tissue adhesives. We analyze these devices for artery compatibility, material composition, potential for intimal damage, risks of thrombosis and restenosis, and complications arising from their deployment and maintenance. Additionally, we discuss the challenges faced in the development and clinical application of sutureless anastomotic techniques. Ideally, a sutureless anastomotic device or technique should eliminate the need for vessel eversion, mitigate thrombosis through either biodegradation or the release of antithrombotic drugs, and be easily deployable for broad use. The transformative potential of sutureless anastomotic approaches in microvascular surgery highlights the necessity for ongoing innovation to expand their applications and maximize their benefits.

3D and 4D assembly of functional structures using shape-morphing materials for biological applications

3D structures are crucial to biological function in the human body, driving interest in their in vitro fabrication. Advances in shape-morphing materials allow the assembly of 3D functional materials with the ability to modulate the architecture, flexibility, functionality, and other properties of the final product that suit the desired application. The principles of these techniques correspond to the principles of origami and kirigami, which enable the transformation of planar materials into 3D structures by folding, cutting, and twisting the 2D structure. In these approaches, materials responding to a certain stimulus will be used to manufacture a preliminary structure. Upon applying the stimuli, the architecture changes, which could be considered the fourth dimension in the manufacturing process. Here, we briefly summarize manufacturing techniques, such as lithography and 3D printing, that can be used in fabricating complex structures based on the aforementioned principles. We then discuss the common architectures that have been developed using these methods, which include but are not limited to gripping, rolling, and folding structures. Then, we describe the biomedical applications of these structures, such as sensors, scaffolds, and minimally invasive medical devices. Finally, we discuss challenges and future directions in using shape-morphing materials to develop biomimetic and bioinspired designs.

A Novel Sutureless Anastomotic Device in a Swine Model: A Proof of Concept Study

INTRODUCTION

Vascular reconstruction requires technical expertise and is often time consuming. As a novel alternative to traditional hand-sewn vascular anastomoses, the VasoLock (VL), is a nonabsorbable, sutureless anastomosis device with traction anchors designed to hold free artery ends together. These anchors do not penetrate the vessel wall but adhere by leveraging the elasticity of the vessels to fasten blood vessels together. This pilot study assesses the performance and patency of this novel device in a porcine model of femoral artery injury.

METHODS

Female swine (n = 7) underwent femoral artery exposure for a total of 10 VL implanted. Study animals underwent hemodilution to a target hematocrit of 15% and ROTEM was used to assess coagulopathy, followed by an arterial injury via transection. The VL was inserted without any sutures. Flow-probe monitors were positioned proximal and distal to the device and flow rates were measured continuously for a total of 90 min. Flow was analyzed and presented as a ratio of distal to proximal flow with the slope of this ratio across time subsequently determined. Angiographic assessment was completed to evaluate for patency and technical complications after 90 min of implant.

RESULTS

The average animal weight was 44.1 ± 3.2 kg. The average mean arterial pressure at the time of implant was 51.2 ± 7.8 mmHg, median heart rate was 77.4 (IQR = 77.25-157.4) beats per minute, and average temperature was 36.1 ± 1.5°C. The baseline hematocrit was 13.5 ± 3.0%, average pH was 7.20 ± 0.1, average clotting time was 154.1 ± 58.7 s and average clot formation time was 103.4 ± 10.9 s all demonstrating the acidotic, hypothermic, and coagulopathic state of the swine at the time of insertion. During the 90-min observation period, the average flow gradient identified across the VL was 0.99 ± 0.24, indicating no significant change in flow across the VL. The average slope of the gradients was 0.0005 (P = 0.22), suggesting the ratio of proximal and distal flow did not change over the 90 min. Following 90 min of dwell time, all VL were patent without technical complication. Angiographic assessment at 90 min demonstrated no evidence of dissection, device migration, arterial extravasation, or thromboembolism with any of the 10 devices.

CONCLUSIONS

This pilot study demonstrated technical feasibility of the novel VL device over a 90-min observation period. All VL were patent and no negative events or complications were identified. This technology demonstrated significant promise in a coagulopathic state: additional investigation, involving long-term survival, is warranted for further validation.

Less-Suture Vascular Anastomosis: Development of Alternative Protocols with Multifunctional Self-Wrapping, Transparent, Adhesive, and Elastic Biomaterials

Blood vessel anastomosis by suture is a life-saving, yet time-consuming and labor-intensive operation. While suture-less alternatives utilizing clips or related devices are developed to address these shortcomings, suture anastomosis is still overwhelmingly used in most cases. In this study, practical "less-suture" strategies are proposed, rather than ideal "suture-less" methods, to reflect real-world clinical situations. In the case of rat artery (d = 0.64 mm) anastomosis, the less-suture anastomosis involves the application of thin, adhesive, transparent, and self-wrapping films to the site. This surprisingly reduces the number of stitches required from ten (without films) to four (with films), saving 27 min of operating time per vessel. Furthermore, the decreased number of stitches largely alleviates fibrosis-mediated wall-thickening. Thus, a less-suture strategy is particularly useful for anastomosis of multiple vessels in emergency conditions and small-diameter vessels.

The Feasibility of Debranching Aortic Arch and Visceral Arteries with Sutureless Telescoping Anastomoses During Open Aortic Aneurysm Repair

Background

Open repair of aortic aneurysms frequently requires reimplantation of major aortic vessels. Traditional techniques can be time consuming, require meticulous hemostasis, and risk aneurysmal patch degeneration, which can require a challenging reoperation. We describe our experience using a stent graft to create a sutureless anastomosis that obviates these drawbacks.

Methods

Between April 2018 and March 2021, all consecutive adult patients who underwent open repair of the aorta with at least one supra-aortic trunk or visceral vessel reimplanted using the sutureless anastomotic technique were included. Anastomoses were constructed by bridging a branch graft and the target artery with a Viabahn self-expanding stent (W.L. Gore & Associates, Flagstaff, AZ). Clinical information and perioperative outcomes for the patients were collected and analyzed.

Results

Among 26 patients, 50 individual aortic vessels were debranched using sutureless self-expanding stent anastomoses, including 42 visceral vessels and 8 supra-aortic trunk vessels. Technical success was 100%. The median time to complete the anastomosis was 3 minutes, 12 seconds (range, 2-6 minutes). Perioperative mortality was 15% (n = 4). No stent-related complications, such as occlusion, bleeding, stroke, renal failure requiring hemodialysis, bowel ischemia, or the need for anastomotic reintervention, occurred. Follow-up imaging at 1 year revealed a 100% patency rate and no anastomotic stenosis, misalignment, or kinking.

Conclusions

The sutureless anastomosis technique to debranch the aorta during open aortic aneurysm repair is technically feasible and reliably hemostatic and does not require early reintervention. The operative outcomes have been acceptable, and the short-term follow-up imaging findings demonstrated excellent patency without anastomotic kinking. In select cases, sutureless anastomoses are a possible alternative to traditional sutured anastomoses during aortic debranching. Further research is needed to compare the operative times and long-term patency of sutureless anastomosis to those of traditional sutured techniques.

Clampless 2 Device: Experimental Study of a Lateral Aorto-Prosthetic Anastomosic Device Without Clamping or Suturing

BACKGROUND

To offer an alternative to conventional techniques of lateral prosthetic anastomosis on arteries which require a long training, and impose an extensive open surgery, we are proposing the clampless 2 device (C2D) implanted by a simple arterial puncture and allows a lateral implantation of a polytetrafluoroethylene (PTFE) vascular graft in an artery, without arterial clamping or suture.

METHODS

C2D is a "T" shaped 25-mm long and 8-mm diameter Nitinol stent with a 6-mm PTFE graft prosthesis mounted laterally on the stent, and implanted in an artery, via a 21-French sheath, and a compliant balloon inflation. In vitro testing of the C2D was first performed on a bench including a segment of a 7-mm internal diameter pig abdominal aorta. A series of 5 consecutive C2D implantation was analyzed with evaluation of the implantation time and the fluid losses at a fluid pressure of 80 and 150 mm Hg. The C2D implantation was finally controlled by angioscopy. An aorto-iliac bypass was then secondly performed on 8 living sows, with a side-to-end C2D implantation in the infrarenal abdominal aorta, followed by a conventional end-to-end prosthetic left iliac trunk anastomosis. The C2D and distal conventional anastomotic times were evaluated, as well as the total operative time and blood loss. A postoperative angiogram was systematically performed.

RESULTS

The C2D was successfully implanted in all 5 in vitro tests, with an average implantation time of 2'58 (range: 2'25-3'22). The mean value of fluid losses was 84 ml (range: 67-94 ml), with no fluid leakage occurring at 80- and 150-mm Hg pressure. All anastomoses were patent after macroscopic study by angioscopy with a perfect application of the stent in the aortic wall. In 8 living sows (mean weight: 42 kg, 37-50 kg), an aorto-left iliac bypass was successfully implanted in all cases, with a total mean procedure time of 101 min (range: 90-130 min), and an average fluid loss of 77 ml (range:20-120 ml). The mean implantation time was 4'39 (range 3'29-5'52) for C2D and 16 min (range 12-17 min) to perform the conventional distal prosthetic-iliac anastomosis. Systematic arteriographic and angioscopy control showed perfect patency of the C2D implantations.

CONCLUSIONS

Preliminary in vitro and acute in vivo testing of C2D implantation show good early results, allowing further long-lasting pig experiments on the way to human homologation.