Effect of Fibrin Adhesive Application in Microvascular Anastomosis: A Comparative Experimental Study

The use of commercial fibrin glue in dermal replacement material reduces angiogenic and lymphangiogenic gene and protein expression in vitro

BACKGROUND

Commercial fibrin glue is increasingly finding its way into clinical practice in surgeries to seal anastomosis, and initiate hemostasis or tissue repair. Human biological glue is also being discussed as a possible cell carrier. To date, there are only a few studies addressing the effects of fibrin glue on the cell-molecular level. This study examines the effects of fibrin glue on angiogenesis and lymphangiogenesis, as well as adipose-derived stem cells (ASCs) with a focus on gene and protein expression in scaffolds regularly used for tissue engineering approaches.

METHODS

Collagen-based dermal regeneration matrices (DRM) were seeded with human umbilical vein endothelial cells (HUVEC), human dermal lymphatic endothelial cells (LECs), or adipose-derived stem cells (ASC) and fixed with or without fibrin glue according to the experimental group. Cultures were maintained for 1 and 7 days. Finally, angiogenic and lymphangiogenic gene and protein expression were measured with special regard to subtypes of vascular endothelial growth factor (VEGF) and corresponding receptors using Multiplex-qPCR and ELISA assays. In addition, the hypoxia-induced factor 1-alpha (HIF1a) mediated intracellular signaling pathways were included in assessments to analyze a hypoxic encapsulating effect of fibrin polymers.

RESULTS

All cell types reacted to fibrin glue application with an alteration of gene and protein expression. In particular, vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor B (VEGFB), vascular endothelial growth factor C (VEGFC), vascular endothelial growth receptor 1 (VEGFR1/FLT1), vascular endothelial growth receptor 2 (VEGFR2/KDR), vascular endothelial growth receptor 3 (VEGFR3/FLT4) and Prospero Homeobox 1 (PROX1) were depressed significantly depending on fibrin glue. Especially short-term fibrin effect led to a continuous downregulation of respective gene and protein expression in HUVECs, LECs, and ASCs.

CONCLUSION

Our findings demonstrate the impact of fibrin glue application in dermal regeneration with special regard to angiogenesis and lymphangiogenesis. In particular, a short fibrin treatment of 24 hours led to a decrease in gene and protein levels of LECS, HUVECs, and ASCs. In contrast, the long-term application showed less effect on gene and protein expressions. Therefore, this work demonstrated the negative effects of fibrin-treated cells in tissue engineering approaches and could affect wound healing during dermal regeneration.

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.

Conventional versus fibrin-glue-augmented arterial microanastomosis: An experimental study

The purpose of this experimental study was to develop an alternative technique of arterial microanastomosis using only 2 stay-sutures augmented with fibrin glue, and to compare it to the conventional technique in arteries of varying diameters mimicking hand arteries. Eight anastomoses were performed in 7 male rats, including 1 anastomosis each on the 2 femoral, iliac, and carotid arteries, and 2 on the subrenal aorta. The conventional technique was used on one side and on the first aorta anastomosis, while augmented anastomoses were performed on the other side and on the second aorta. Patency was tested 10 min after unclamping; clamping time, blood loss, anastomosis quality score (out of 15 points) and artery diameter were recorded. In arteries of diameter 0.5-2.2 mm, augmented anastomoses were on average 10.7 ± 3.2 min faster to perform (p < 0.0001), with an average of 1.3 ± 0.9 g less blood loss (p < 0.0001) and an average of 2.6 ± 2.5 points higher quality score (p < 0.0001). There were no significant differences between the two techniques in terms of patency rate, regardless of artery size. However, 3 of the 7 augmented anastomoses were non-permeable in the femoral subgroup (i.e., submillimetric arteries). This straightforward technique appears to be time-saving and reliable, provided that the repaired artery is of sufficient size. Subject to clinical validation, this technique might help surgeons treating extensive hand wounds with multiple severed neurovascular bundles.

Evaluation of the long-term results of vascular anastomosis using polyurethane adhesive and shape-memory stent in the rat carotid artery model

INTRODUCTION

In free flaps, 5%-10% of complications are related to failure of sutured vascular anastomoses. Adhesive-based microvascular anastomoses are potential alternatives but are associated with failure rates of 70% in research studies. VIVO is a new adhesive with slow biodegradation within 6 months that has shown a 100% patency rate in research studies over 2 h observation time but long-term patency has not been evaluated. The authors hypothesize that VIVO will enable a reliable microvascular procedure comparable to sutured anastomoses over a 28-day period.

MATERIALS AND METHODS

The right common carotid artery of 60 male Sprague Dawley rats, ~450 g, were used for microvascular end-to-end anastomosis. VIVO was applied with reduced sutures with a temporary catheter in one group and in the other with a custom-shaped memory stent. Anastomoses with eight interrupted sutures served as control. All groups were n = 20. Anastomosis time and bleeding were recorded for each procedure. Doppler flowmetry was performed 20 min, 1, 10, and 28 days postoperatively. Postmortem toluidine staining was used for semi-quantitative analysis of stenosis, thrombosis, necrosis, and aneurysm formation by histologic evaluation.

RESULTS

No occlusion was detected 20 min and 1 day postoperative, and after 28 days of observation in all anastomoses. The anastomosis time of the VIVO with catheter group was about 32% significantly faster than the VIVO with stent group. In the VIVO group with stent, the bleeding time was ~80% shorter than in the control group with 2.1 ± 0.3 and VIVO with catheter 2.0 ± 0.5 (p ≤ .001 each). Minor and nonsignificant stent-associated thrombus formation and stent-typical intraluminal stenosis were detected exclusively in the VIVO with stent group.

CONCLUSION

Within the limitations of a rat study, the use of VIVO in anastomosis showed promising results. VIVO with catheter was found to be advantageous.

Biodegradation and Immunological Parameters of Polyurethane-based Tissue Adhesive in Arterial Microvascular Anastomoses - a Long-term in Vivo Study

In microsurgical anastomosis, non-synthetic fibrin-based adhesives have predominantly shown superior properties to synthetic cyanoacrylates, but they have hardly any clinical application. This study aimed to investigate the local and systemic effects of synthetically produced biodegradable adhesive VIVO when used in microsurgical anastomosis. VIVO was used in two different anastomosis procedures in the common carotid artery in a rat model: VIVO in addition to a temporary catheter (VIVO TC) and VIVO with a custom-shaped memory nitinol stent (VIVO SM). Conventionally sutured anastomoses served as controls (C). Tissue response was assessed by in vivo fluorescence imaging and histological examination. The systemic effects of biodegradation were measured using hematologic parameters and serum levels of transaminase activity and lactate dehydrogenase. Finally, the degree of local adhesion of the different anastomotic procedures was evaluated. Fluorescence imaging showed reduced inflammatory blood flow in the VIVO TC group. Histological analysis of the anastomosed vessels also revealed significantly more inflammation in C than in the two adhesive groups. The severity of VIVO adhesions proved acceptable, and no histotoxic effects of VIVO were detected. The data demonstrated that the synthetic tissue adhesive VIVO is a reliable and- compared to sutures-tissue-friendly adhesive for microsurgical anastomoses. This article is protected by copyright. All rights reserved.

Evaluation of a biocompatible sealant for on-demand repair of vascular defects-a chronic study in a large animal model

OBJECTIVES

Existing surgical sealants fail to combine design requirements, such as sealing performance, on-demand activation and biocompatibility. The aim of this study was to compare the effectiveness and safety of the SETALIUM™ Vascular Sealant (SVS), a novel, on-demand activatable sealant, with the commercial sealant, BioGlue®, for the repair of vascular defects.

METHODS

In an in vivo porcine model, the use of SVS was compared with BioGlue, for sealing 2-mm defects of the carotid artery and jugular vein. Animals were followed for 7 days and 5 weeks (each time point and per experimental group, n = 4), respectively. The degree of stenosis and flow velocity was determined, and the local tissue response was evaluated.

RESULTS

In vivo incision closure succeeded in all cases, and SVS was superior in clinical usability, enabled by its on-demand activation. Unlike BioGlue, SVS use did not induce stenosis and was associated with physiological blood flow in all cases. Moreover, closure with SVS was associated with a low inflammatory reaction and no thrombus formation or intima proliferation, in contrast to BioGlue.

CONCLUSIONS

SVS demonstrated effective and rapid sealing of 2-mm vascular defects, with favourable biocompatibility compared to BioGlue. Thus, SVS seems to be an effective and safe vascular sealant.

The safety and benefit of using oxidized regenerated cellulose to position free flap pedicle in head and neck reconstruction

BACKGROUND

Oxidized regenerated cellulose (ORC; Surgicel®; Ethicon, Neuchâtel, Switzerland) is an absorbable hemostatic agent used for hemostasis in operation, although some surgeons use it to position free flap pedicles. The increasing risk of vessel compromise is a huge concern. However, no scientific data to date demonstrate the safety and benefit of using ORC in microvascular surgery. In the present study, we compared the outcome of microvascular head and neck reconstruction with and without pedicle placement using ORC.

MATERIALS AND METHODS

From January 2015 to December 2017, we reviewed patients undergoing microvascular surgery with free fibular osteocutaneous flap in our hospital. The patients were divided into the ORC group and non-ORC group and their baseline characteristics and outcomes were compared.

RESULTS

In total, there were 27 patients in the ORC group and 67 in the non-ORC group. The non-ORC group had significantly higher cigarette consumption (70.4% vs. 89.6%; p = .022). The outcome of the ORC group was better regarding arterial thrombosis (0% vs. 3%), flap failure (0% vs. 4.5%), hematoma (7.4% vs. 10.4%), and wound complications (25.9% vs. 44.8%). The ORC group had a worse result than the non-ORC group for vein thrombosis (7.4% vs. 4.5%) and duration of hospitalization (24.111 days vs. 23.627 days). However, none of above results was significant.

CONCLUSIONS

Though this study was underpowered to detect the differences, the results showed a trend toward better outcomes of flaps and wounds in the ORC group. It seems that using ORC in this field is safe and beneficial.

Two-suture fish-mouth end-to-side microvascular anastomosis with fibrin glue

The most decisive step during free tissue transfers and replantation surgery may be respected as microvascular anastomosis. The conventional end-to-side anastomosis technique with simple interrupted sutures is well established and proven to be successful. On the other hand, conventional technique can be time consuming and can cause vascular thrombosis, vessel narrowing, and foreign-body reactions. Search for a more rapid and secure alternative to conventional technique is carried on. In this study, we defined a new technique for end-to-side anastomosis with fish-mouth incisions and application of fibrin glue and compared our results with those we obtained with conventional end-to-side anastomosis. We evaluated end-to-side anastomosis of carotid arteries of a total number of 64 Wistar-Albino rats. In control group (n = 32), conventional anastomoses with 8 to 10 sutures were performed. In experimental group (n = 32), fish-mouth incisions were applied first on the recipient artery, followed by performing anastomosis with only 2 corner sutures and applying commercially available fibrin glue. Time taken to perform the anastomosis was significantly shorter with the experimental group (P = 0.001), whereas early and late patency and aneurysm rates were comparable to those achieved with control group. Histological evaluation did not point out any significant differences between the groups. We have defined a rapid and safe alternative technique of end-to-side anastomosis with the use of fibrin glue. This method may be an alternative especially where multiple anastomoses are required or where it is difficult to approach anastomotic line, as it is easily performed, rapid, safe, and not involving any complex equipments.

Use of continuous horizontal mattress suture technique in end-to-side microsurgical anastomosis

PURPOSE

The aim of our study was to improve the new suturing method which increases the success rate of end to side microsurgical anastomosis.

METHODS

Thirty-six Sprague-Dawrey rats were randomly divided into three groups that consist of 12 rats in closed envelope method. The end-to-side microsurgical anastomosis procedures were applied by the same surgeon between left main carotid artey and left external jugular vein. The surgical evaluations were performed with anastomosis duration, leakage evaluation, vessels patency, aneurysm improvement and histological assesment.

RESULTS

End-to-side anastomosis, which was applied with Continuous Horizontal Mattress suture, gave significantly better results in terms of leakage, anastomosis openness, aneurysm and histologic assesment. Also anastomosis duration of Continuous Horizontal suture was significantly faster than Simple Intermittent suture.

DISCUSSION

Our study revealed that the Continuous Horizontal Mattress suture technique had the advantages of providing uninterrupted vessel flow in a shorter time, and minimal intraluminal suture material, which increase thrombosis risk. Also 'sac-mouth' effect of Continuous suture technique was prevented by Horizontal Mattress technique.

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.

Anastomosis with fish-mouth technique using fibrin glue

Researchers have made numerous attempts to shorten anastomosis duration since Jacobson first used the term microvascular surgery in 1960. However, none of these alternatives has its combination of facility, low cost, reliability, durability, and high success rate. This study aimed to shorten the anastomosis duration, especially in operations that require multiple anastomoses, and the authors performed experimental anastomoses with the fish-mouth technique using fibrin glue. This technique first involves 2 longitudinal incisions made 180 degrees apart in the shape of a fish mouth at each vessel end, thus creating a pair of equal-sized, full-thickness flaps on both vessels. These incisions, equal in length, were as long as the radius of the vessel. Two simple stay-sutures placed on the corners of the flap bases and vessels were approximated. Then, the anastomosis site was sealed with fibrin glue. Both control and experimental groups are consisted of 32 rats. This study assessed and statistically evaluated the groups with biopsies on days 3, 7, 14, and 21 and also assessed patency rates, microaneurysm formation, histologic healing patterns, and operation duration. The present study concluded that anastomosis with fish-mouth technique using fibrin glue takes less time, requires fewer sutures, decreases the amount of foreign materials in direct contact with the blood stream, creates less foreign-body reaction in the vessel wall, and everts contact surfaces. With these advantages, this technique provides a reliable and successful alternative, especially in operations requiring multiple anastomoses.