Microvascular anastomosis using fibrin glue and venous cuff in rat carotid artery

Vaso-Lock for sutureless anastomosis in a pig arteriovenous loop model

A vascular anastomosis is a critical surgical skill that involves connecting blood vessels. Traditional handsewn techniques can be challenging and resource intensive. To address these issues, we have developed a unique sutureless anastomotic device called Vaso-Lock. This intraluminal device connects free vascular ends using anchors to maintain traction and enable a rapid anastomosis. We tested the anastomotic capability of Vaso-Locks in a pig common carotid-internal jugular arteriovenous model. The use of Vaso-Lock allowed us to accomplish this procedure in less than 10 min, in contrast to the approximately 40 min required for a handsewn anastomosis. The Vaso-Lock effectively maintained patency for at least 6 weeks without causing significant tissue damage. Histological analysis revealed that the device was successfully incorporated into the arterial wall, promoting a natural healing process. Additionally, organ evaluations indicated no adverse effects from using the Vaso-Lock. Our findings support the safety and effectiveness of the Vaso-Lock for arteriovenous anastomosis in pigs, with potential applicability for translation to humans. Our novel sutureless device has the potential to advance surgical practice and improve patient outcomes.

Validation of Novel Microsurgical Vessel Anastomosis Techniques: A Systematic Review

INTRODUCTION

 Thorough validation of novel microsurgical techniques is deemed essential before their integration into clinical practice. To achieve proper validation, the design of randomized controlled trials (RCTs) should be undertaken, accompanied by the execution of comprehensive statistical analyses, including confounder adjustment and power analysis. This systematic review aims to provide an encompassing overview of the validation methodologies employed in microsurgical studies, with a specific focus on innovative vessel anastomosis techniques.

METHODS

 A literature search was conducted in PubMed for articles describing the validation of novel microsurgical vessel anastomosis techniques in animal or human subjects.

RESULTS

 The literature search yielded 6,658 articles. A total of 6,564 articles were excluded based on title and abstract. Ninety-four articles were assessed for full-text eligibility. Forty-eight articles were included in this systematic review. Out of 30 comparative studies, 9 studies validated novel modified interrupted suture techniques, 6 studies modified continuous techniques, 6 studies modified sleeve anastomosis techniques, 1 study a modified vesselotomy technique, 7 studies sutureless techniques, and 1 study a modified lymphaticovenular anastomosis technique. Twenty-eight studies contained animals (n = 1,998). Fifteen animal studies were RCTs. Two studies contained human/cadaveric subjects (n = 29). Statistical power analysis and confounder adjustment were performed in one animal study. Out of 18 noncomparative studies, 5 studies validated novel modified interrupted suture techniques, 1 study a modified continuous technique, 2 studies modified sleeve anastomosis techniques, 4 studies modified vesselotomy techniques, 4 studies sutureless techniques, and 2 studies modified lymphaticovenular anastomosis techniques. Ten studies contained animal subjects (n = 320), with two RCTs. Eight studies contained human subjects (n = 173). Statistical power analysis and confounder adjustment were performed in none of the animal or human studies.

CONCLUSION

 The current methods of microsurgical technique validation should be reconsidered due to poor study design. Statistical analysis including confounder adjustment and power analysis should be performed as a standard method of novel technique validation.

Comparison of a coupling system and the suture method in end-to-side microvascular anastomosis in head and neck reconstruction

BACKGROUND

Use of coupling devices in microvascular anastomosis continues to increase, but it is not yet actively used in end-to-side (ETS) anastomosis because there is no standard method. Therefore, we propose an easy and time-saving ETS micro-anastomosis method using coupling devices in head and neck reconstruction and compare it with the conventional suture method.

MATERIALS AND METHODS

We retrospectively reviewed 30 consecutive cases (43 anastomoses) of ETS anastomosis in head and neck reconstruction from 2018 to 2022. Patient characteristics, operative details, and anastomosis time were evaluated. When using the coupling device, a cross incision was created in the recipient vessel to form vascular flaps. By pulling the flaps out of the ring, the intact vessel lining was fixed. Other procedures were the same as for a traditional anastomosis.

RESULTS

The mean anastomosis time was 12.81 min (range, 6.7-24.87) for the suture and 4.96 min (range, 2.02-9.4) for the coupling device, a statistically significant difference (p-value <.00005). There was no venous insufficiency or flap failure with either method.

CONCLUSIONS

ETS venous anastomosis using the coupling device is an easy-to-use, safe, and timesaving procedure for head and neck reconstruction.

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 &lt; 0.0001), with an average of 1.3 ± 0.9 g less blood loss (p &lt; 0.0001) and an average of 2.6 ± 2.5 points higher quality score (p &lt; 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.

Laparoscopic Liver Resection Enhanced by an Intervention-Guided Fluorescence Imaging Technique Using Sodium Fluorescein

BACKGROUND AND OBJECTIVES

In laparoscopic liver resections, tumor localization is a critical aspect of ensuring clear resection margins and preserving the hepatic parenchyma. In this study, we designed a fluorescence imaging technique using a new fluorophore for tumor localization.

MATERIALS AND METHODS

Immediately before laparoscopic or transthoracic liver resection, microcatheter was inserted through the hepatic artery and used to engrave the segment containing the tumor in the intervention room. Under blue light, the fluorescence of the lesion was visually confirmed, and the location was determined through intraoperative sonography. After tumor localization, liver resection was performed.

RESULTS

From February 2017 to March 2020, 24 patients underwent laparoscopic liver resection (LLR) or video-assisted transthoracic liver resection (VTLR) using intervention-guided fluorescence imaging technique (IFIT).

CONCLUSIONS

IFIT can provide some advantages in the field of LLR. In addition, in cases of VTLR for hepatocellular carcinoma in the superior posterior segment in patients with marginal liver function, IFIT is considered useful.

Microvascular anastomosis techniques using the medical adhesive VIVO and expandable micro-stents in a rat carotid artery model

BACKGROUND

Sutured anastomosis remains the gold standard in microvascular surgery. The procedure is not free of complications and is a time-consuming operation requiring a high level of experience. The aim of this study was to develop new methods for a stable, faster, and safer anastomosis using a novel biodegradable adhesive, VIVO, and a custom-made microvascular stent.

METHODS

The VIVO medical adhesive was used for a total of 30 anastomoses in rats in the right carotid artery: 15 anastomoses were performed with a temporary intraluminal catheter, VIVO, and reduced sutures (VIVO + TC). A further 15 anastomoses were performed with nitinol stents, VIVO, and reduced sutures (VIVO + SM). Sutured anastomoses served as controls (C) and were performed on the left carotid arteries of the 30 rats. Operation and bleeding times were assessed, and patency was evaluated by Doppler flowmetry and indocyanine green (ICG) angiography. Subsequently, the anastomoses were evaluated histopathological.

RESULTS

The overall patency was recorded as 100% in all groups. No thrombosis or circulatory disturbance was found. Compared to C and VIVO + SM, VIVO + TC proved to be significantly less traumatic, less demanding, and time-saving. The sealing properties of VIVO lead to shorter bleeding times and less oozing. In contrast, VIVO + SM proved to be the most technically demanding and time-consuming procedure.

CONCLUSION

The success of a microvascular sutured anastomosis is determined by a short ischemic interval. Compared to sutured anastomosis, VIVO + TC showed ease of use as well as shorter time taken for anastomosis, less trauma, and lower blood loss. More long-term studies on the functions, biological interactions, and survival rates of glue-based anastomoses need to be initiated.

Who needs extra time? Amniotic membrane wrapped pauci-suture model for rapid anastomoses. J Plast Surg Hand Surg 2019;53:89-96. [PMID: 30654665 DOI: 10.1080/2000656x.2018.1550419]

An ideal anastomosis method will obtain the highest post-anastomotic vessel patency and will repair the vessel anatomically with minimal thrombosis in an easier, faster and cheaper fashion. To achieve these goals an anastomosis model using an amniotic membrane is introduced. The study was performed on the femoral arteries of 22 Wistar Albino rats (11 control group, 11 experimental group). In the experiment group, the microvascular anastomosis was completed with three sutures and a patch of amniotic membrane which was wrapped around the anastomotic site. The conventional anastomosis technique with eight sutures was performed in the control group. The effects of the model on the patency and histological structure of the vessels were evaluated. As a result, normal patency was determined radiologically and macroscopically in all of the anastomoses. No thrombosis or aneurysm was detected in any of the anastomoses. In the angiographic study, vessel patency was detected in both the control and experimental groups. The average time to complete the arterial anastomosis was 18.14 (±2.84) and 10.39 (±2.45) minutes in the control and the experiment groups respectively. In the histological studies, anti-eNOS staining revealed that endothelin levels were significantly higher in the experimental group. This method describes a new anastomosis model in microvascular surgery with promising results that call for additional experimental studies and further clinical implementations. We believe that this experimental technique can be put into clinical practice as an alternative to the conventional microvascular anastomosis technique.