Reduction of Anastomotic Time Through the Use of Cyanoacrylate in Microvascular Procedures

Background: Ever since the description of the first microvascular anastomosis, numerous alternative methods have been described to the classical approach. Tissue adhesive has shown promising result in previous studies and can be a fast and efficient alternative which still requires more studies to allow its clinical implementation. Methods: A randomized comparative experimental study was conducted on rats' femoral arteries and an end-to-end anastomosis was performed in order to compare 2 anastomosis techniques. In one group, a simple interrupted suture was utilized, whereas in the second group a combination between fewer sutures and tissue adhesive was used. The anastomotic time, total operative time, blood flow velocity before, immediately after and 48 hours after the procedure, as well as an independent grading of the anastomosis immediately after the procedure were performed. Magnetic resonance imaging (MRI) was performed in order to assess the degree of stenosis. After euthanasia, histology and scanning electron microscopy (SEM) were performed on the vessels in order to assess possible complications. Results: A total of 24 anastomoses were performed, of which 12 with a classic technique and 12 with an adhesive technique. All the anastomoses were patent with a significant reduction of anastomotic and total operative time. The grading of the anastomoses showed better results in the classic suture group. The blood flow velocities were not statistically significant between the 2 groups. On MRI there was one stenotic anastomosis, whereas histology and SEM showed more complications on the adhesive group. Conclusion: Anastomotic times were significantly lower with a non-significant trend toward more thrombotic complications in the adhesive group. Further improvement of the glue properties and refinement of the technique will likely make it a viable alternative to interrupted suturing in the future.

A polyurethane-based surgical adhesive for sealing blood vessel anastomoses-A feasibility study in pigs

Peri- and postoperative anastomotic leakage from blood vessel anastomosis is a common and potentially life-threatening complication. As an adjunctive therapy providing an additional layer of safety, a new biodegradable, polyurethane-based adhesive was developed. It consists of two components: an isocyanate-functionalized prepolymer and an amino-based curing agent. The adhesive was investigated in a porcine animal model to seal sutured blood vessel anastomoses of arteries, veins, aortas and prosthetic aortic graft replacements. The material-determined properties of the adhesive like viscosity, processing and polymerization time as well as bonding strength were well suited for this application. The adhesive stopped perioperative suture-line bleedings and stayed on all anastomoses until sacrifice. Hematological and serological inflammation marker assessments were unobtrusive. The histological evaluation showed a mild to moderate local tissue reaction to the adhesive constituting a physiological, non-adverse tissue-biomaterial interaction. The adhesive did not interfere with vascular wound healing. The adhesive demonstrated to be suitable to improve the outcome of cardiovascular surgeries by securing the classical sutured anastomoses in a fast, easy and safe manner. However, further studies are required to quantitatively evaluate efficacy in terms of anastomotic leakage prevention as well as long-term tissue compatibility and degradation.

A systematic review of sutureless vascular anastomosis technologies

Vascular anastomoses typically involve a handsewn technique requiring significant surgical training, expertise, and time. The aim of our systematic review was to identify and describe sutureless vascular anastomosis techniques. We performed a systematic review of all sutureless vascular anastomosis technologies published in MEDLINE, PubMed, Embase, CINAHL, Cochrane, Web of Science, and Scopus Library databases and a patent review using US Patent and Trade Office Application, US Patent and Trademark Office Patent, Google Patents, Lens, Patent Quality Through Artificial Intelligence, SureChEMBL, and E-Space Net. Data from inclusion studies and patents published between January 1, 1980 and July 15, 2021 were abstracted to describe their category, anastomosis type and configuration, study types, and advantages and disadvantages encountered with each technology. Two hundred eleven original studies and 475 patents describing sutureless vascular anastomosis technologies were identified. In the literature, stents/stent-grafts/grafts (n = 61), lasers (n = 53), and couplers (n = 27) were the predominant device categories. In the patent review, adhesive technologies (n = 103), stents/stent-grafts/grafts (n = 68), and mechanical connectors (n = 61) predominated. The majority of studies involved in vivo animal studies (n = 193); 32.2% (n = 68) of investigations involved human trials; and 17.9% (n = 85) of patent technologies were approved by the US Food and Drug Administration. The main advantages described for sutureless anastomosis technologies included faster procedure time and greater patency rates compared with handsewn anastomoses. The main disadvantages included reduced vessel compliance, stenosis, leakage, and device costs. The appeal of sutureless technology is substantiated by numerous animal trials, but their use in humans remains limited. This may be a reflection of strict regulatory criteria and/or vascular complications associated with currently available technologies.

Sutureless venous microanastomosis using thermosensitive poloxamer and cyanoacrylate: experimental study on a rat model

INTRODUCTION

Sutureless microvascular anastomoses could simplify the microvascular field, shortening operative time and improving the final outcome. The use of thermosensitive poloxamers (TP407) together with the application of cyanoacrylate as an alternative method for conventional sutures was well-documented for arteries, but not for veins. The purpose of our study was to prove the feasibility of this technique for venous anastomoses and compare it with the traditional hand-sewn technique on a rat model.

MATERIALS AND METHODS

Twenty male Sprague-Dawley rats that weighed between 265 and 310 g were used. In the sutureless group (SG), 20 left external jugular veins (LEJV) end-to-end anastomoses were performed using a T704 and cyanoacrylate glue. They were compared to 20 right external jugular veins (REJV) anastomoses sutured with conventional 10-0 stitches (control group - CG). Diameters of veins, anastomosis time, and patency rate at 15 days were reported. Foreign body reaction was assessed histologically.

RESULTS

The mean diameter of the LEJV was 0.94 ± 0.1 mm and 0.95 ± 0.09 mm for the REJV. The mean anastomosis time was 11.9 ± 1.37 min for the SG and 27.75 ± 3.31 min for the CG. In the latter group, the immediate patency rate was 95% and 90% at 15 days. For the SG group, 90% of the anastomoses were patent immediately and 85% at 15 days.

CONCLUSION

TP407 and cyanoacrylate could offer a fast and reliable technique for sutureless venous anastomoses. Before human application, effectiveness of this method remains to be confirmed in larger animals in a long-term follow-up.

Experimental study of sutureless vascular anastomosis with use of glued prosthesis in rabbits

OBJECTIVE

The objective of this study is to explore the feasibility and efficacy of a new technique for sutureless vascular anastomosis, using glued prosthesis, as a sole anastomosis fixation method in rabbits.

METHODS

Ten rabbits were randomly selected to conduct the experiment. Five rabbits underwent direct anastomosis of infrarenal abdominal aorta, with glued prosthesis. In five other rabbits, reconstruction was done by sutured anastomosis. All animals were immediately examined by echo-Doppler for patency of anastomosis. The burst pressure of the glued anastomosis was measured and compared with that of a sutured artery. The animals were euthanized, and tissue samples were taken for histological examination immediately after the experiment.

RESULTS

Compared to conventional anastomoses, sutureless vascular anastomoses required shorter time of creation and significantly reduced blood loss (P<5%). There was no significant difference on the average blood flow through the anastomosis between two groups at the end of surgery. All anastomoses with glued prosthesis, examined by echo-Doppler, were patent at the anastomotic site, except one, which was stenosed immediately after surgery. In the control group, except one with stenosis, all conventional anastomoses were patent. Mean burst pressure at the anastomotic site for sutureless anastomoses was lower than in control group. Macroscopically, the BioGlue did not demonstrate any adhesion to the surrounding tissue as it was covered by the vascular prosthesis. Histological examination showed low-grade inflammatory reaction in glued anastomoses versus no inflammatory reaction at the sutured anastomoses.

CONCLUSION

This technique may provide a feasible and successful alternative in vascular surgery. However, further long-term studies are necessary to elucidate the break pressure and degree of inflammation at the anastomotic site.

Nonsuture anastomosis of arteries and veins using the magnetic pinned-ring device: a histologic and scanning electron microscopic study

BACKGROUND

The goal of this study was to evaluate the performance of the magnetic pinned-ring device for nonsuture vascular anastomosis.

METHODS

The magnetic pinned-ring device consists of paired magnetic rings that are coated with titanium nitride and embedded in a polypropylene shell; the rings are equipped with alternately spaced holes and titanium pins. The vascular anastomosis procedure using the novel magnetic pinned-ring device was performed on 14 mongrel dogs, and the traditional hand-sewing technique was used on 14 additional dogs. In situ end-to-end anastomoses were performed in the femoral artery and the inferior vena cava. Patency was confirmed through ultrasonographic scans at different time points as late as 24 weeks after surgery. Gross observation, histological staining, and scanning electron microscopy were used to evaluate the results at 24 weeks postoperatively.

RESULTS

The time required to perform the vascular anastomosis was significantly shorter for the magnetic device than for hand sewing. A continuity of re-endothelialization was confirmed in all anastomotic stomas after 24 weeks, and neither formation of aneurysms nor thickening of the vascular wall was noted. The re-endothelialization was smooth at the anastomotic site of the magnetic device, whereas hand sewing resulted in rough and uneven re-endothelialization and the presence of visible sutures. Moreover, the endothelial cells were regularly arranged at the anastomotic site of the magnetic device, whereas different-sized and irregularly aligned endothelial cells were present at the hand-sewn anastomotic site. Use of the magnetic device was associated with significantly decreased deposition of fibrotic collagen and depressed infiltration of inflammatory cells compared with use of the hand-sewing technique.

CONCLUSIONS

The magnetic pinned-ring device offers a simple, fast, reliable, and efficacious technique for nonsuture vascular anastomosis. Use of this device shortens operation time, maintains a high patency rate, and improves the healing of vascular tissue.

Technology-assisted and sutureless microvascular anastomoses: evidence for current techniques

BACKGROUND

Since the birth of reconstructive microvascular surgery, attempts have been made to shorten the operative time while maintaining patency and efficacy. Several devices have been developed to aid microsurgical anastomoses. This article investigates each of the currently available technologies and attempts to provide objective evidence supporting their use.

METHODS

Techniques of microvascular anastomosis were investigated by performing searches of the online databases Medline and Pubmed. Returned results were assessed according to the criteria for ranking medical evidence advocated by the Oxford Centre for Evidence Based Medicine. Emphasis was placed on publications with quantifiable endpoints such as unplanned return to theatre, flap salvage, and complication rates.

RESULTS

There is a relative paucity of high-level evidence supporting any form of assisted microvascular anastomosis. Specifically, there are no randomized prospective trials comparing outcomes using one method versus any other. However, comparative retrospective cohort studies do exist and have demonstrated convincing advantages of certain techniques. In particular, the Unilink™/3M™ coupler and the Autosuture™ Vessel Closure System® (VCS®) clip applicator have been shown to have level 2b evidence supporting their use, meaning that the body of evidence achieves a level of comparative cohort studies.

CONCLUSION

Of the available forms of assisted microvascular anastomoses, there is level 2b evidence suggesting a positive outcome with the use of the Unilink™/3M™ coupler and the Autosuture™ VCS® clip applicator. Other techniques such as cyanoacrylates, fibrin glues, the Medtronic™ U-Clip®, and laser bonding have low levels of evidence supporting their use. Further research is required to establish any role for these techniques.