Sutureless Vascular Anastomoses by N-Butyl-2 Cyanoacrylate Adhesive: An Experimental Animal Study

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 Rat Model of Radiation Vasculitis for the Study of Mesenchymal Stem Cell-Based Therapy

Radiation vasculitis is one of the most common detrimental effects of radiotherapy for malignant tumors. This is developed at the vasculature of adjacent organs. Animal experiments have showed that transplantation of mesenchymal stem cells (MSCs) restores vascular function after irradiation. But the population of MSCs being engrafted into irradiated vessels is too low in the conventional models to make assessment of therapeutic effect difficult. This is presumably because circulating MSCs are dispersed in adjacent tissues being irradiated simultaneously. Based on the assumption, a rat model, namely, RT (radiation) plus TX (transplantation), was established to promote MSC homing by sequestering irradiated vessels. In this model, a 1.5 cm long segment of rat abdominal aorta was irradiated by 160kV X-ray at a single dose of 35Gy before being procured and grafted to the healthy counterpart. F344 inbred rats served as both donors and recipients to exclude the possibility of immune rejection. A lead shield was used to confine X-ray delivery to a 3 cm×3 cm square-shaped field covering central abdominal region. The abdominal viscera especially small bowel and colon were protected from irradiation by being pushed off the central abdominal cavity. Typical radiation-induced vasculopathy was present on the 90^th day after irradiation. The recruitment of intravenously injected MSCs to irradiated aorta was significantly improved by using the RT-plus-TX model as compared to the model with irradiation only. Generally, the RT-plus-Tx model promotes MSC recruitment to irradiated aorta by separating irradiated vascular segment from adjacent tissue. Thus, the model is preferred in the study of MSC-based therapy for radiation vasculitis when the evaluation of MSC homing is demanding.

Α systematic review and meta-analysis of the efficacy of aortic anastomotic devices

OBJECTIVE

One of the factors contributing to complications related to open repair of the aorta is the construction of a hand-sewn anastomosis. Aortic anastomotic devices (AADs), such as the intraluminal ringed graft (IRG), and the anastomotic stenting technique have been developed to perform a sutureless and less complicated anastomosis. This study performed a systematic review and meta-analysis of the literature reporting clinical use of AADs and aimed to assess, primarily, the effect of each device on 30-day overall and operation-related mortality and aortic cross-clamping time and, secondarily, the rate of successful two-sided application of the IRG device and the operation-related morbidity for each device.

METHODS

An electronic search was performed using MEDLINE, Scopus, ScienceDirect, and Cochrane Library by two independent authors. Our exclusion criteria included studies incorporating fewer than three patients and studies reporting results solely from animals or in vitro testing, results solely from end-to-side anastomosis, and results solely from endarterectomy procedures. The last search date was February 1, 2018.

RESULTS

A total of 41 studies were identified that reported outcomes for the use of three different device types: IRG, anastomotic stenting technique, and surgical staplers. The last two types were classified together as the non-IRG group. The meta-analysis included 27 studies with 50 cohorts incorporating 1260 patients. The median age of the incorporated patients was 61.4 years (range, 51-73 years), and 68.9% were male. The operations were performed for the treatment of acute aortic dissection in 82.3%. The pooled overall 30-day mortality rate varied by device type; IRG devices had a mean rate of all-cause mortality of 9.71%, whereas non-IRG devices were associated with a significantly (I² = 15.78%; P for Cochrane Q test < .19) lower rate of death (1.47%). The pooled mean aortic cross-clamping time was 35.83 minutes. Metaregression showed that the performance of two-sided anastomosis with the IRG device significantly decreased the aortic cross-clamping time. However, a successful two-sided ringed anastomosis was performed in approximately half of the cases.

CONCLUSIONS

Taking into account that the majority of operations were performed for the treatment of acute aortic dissection, AADs had a relatively low rate of 30-day mortality. Despite the observed heterogeneity in study protocols and the small sample size in the non-IRG group, the non-IRG group presented with the lowest 30-day mortality rate. Specific device-related complications between the different device types need further investigation.

Biomechanical characterization of a novel ring connector for sutureless aortic anastomosis

The surgical treatment for aortic diseases remains a challenge for any cardiac surgeon. The use of sutureless ring connector in aortic anastomosis can simplify the procedure and shorten anastomosis time. Therefore, we developed a novel device for sutureless aortic anastomosis. A series of experiments were carried out for tensile and leakproof-capacity assessments to verify the feasibility of the ring connector by using fresh swine aorta samples. In in vivo test, the ring connector was implanted in 6 swine with follow-up of 6 months. Radiographic and pathological studies of the aorta were performed. In the tensile tests, the strength was 32.7±5.9 Newton (N) in the sutureless anastomosis group, compared with 73.3±12.5 N in the control group by traditional manual suture. In the leakproof-capacity assessment, no sign of either leakage or bursting was evident at 280 mmHg of internal pressure in the aorta samples. In in vivo tests, it took 9.47±0.3 minutes for the sutureless anastomosis, compared with 15.58±1.39 minutes for hand-sewn suturing. Insertion was easy and rapid. Radiographic and pathological studies were performed at first month, third month and sixth month after surgery, each time obtained from the two swine, showed patency of the anastomosis and no signs of stenosis, blood leakage, migration or pseudoaneurysm formation, except one paralyzed swine developed of thrombo-occlusion at the site of the sutureless anastomosis. The result indicates that this novel ring connector offers considerable promise for sutureless aortic anastomosis.

2-Octylcyanoacrylate for the prevention of anastomotic leak

BACKGROUND

Anastomotic leak after colorectal surgery is a significant cause of morbidity and mortality. The aim of this study was to evaluate the impact of a reinforced colo-colonic anastomosis with tissue adhesive, 2-octylcyanoacrylate (2-OCA), on the integrity of anastomotic healing as measured by anastomotic bursting pressure.

METHODS

Sixty-eight female Sprague-Dawley rats underwent a rectosigmoid colon transection and a sutured end-to-end anastomosis followed by randomization to receive no further intervention or reinforcement with the tissue adhesive, 2-OCA. After seven postoperative days, a macroscopic assessment of the anastomosis, mechanical assessment to determine anastomotic bursting pressure, and a detailed semi-quantitative histopathologic healing assessment were performed.

RESULTS

Thirty-four animals were randomized to each group. Study characteristics did not differ between the groups. There was also no difference in the degree of adhesions present postoperatively. Although there was no difference between the net proximal and distal luminal areas in the two groups (0.37 cm²versus 0.55 cm², P = 0.26), the 2-OCA group exhibited evidence of stricture in 15% of anastomoses as compared with 3% in the suture-only group (P < 0.0001). Histologically, the presence of only fibroblasts density was statistically more evident in the 2-OCA group compared with the sutured-only anastomosis (P = 0.0183). There was not a significant increase in mechanical strength in the 2-OCA group (238.9 mm Hg) versus in the suture-only group (231.8 mm Hg). There was no difference in the rate of anastomotic leak in the 2-OCA as compared with the suture-only group (9.1 versus 8.8%).

CONCLUSIONS

Application of 2-OCA to reinforce a colo-colonic anastomosis clinically provides no benefit to its mechanical strength and detrimentally increases the rate of obstruction and/or stricture in this in vivo model.

Comparison of Arterial Repair through the Suture, Suture with Fibrin or Cyanoacrylate Adhesive in Ex-Vivo Porcine Aortic Segment

Introduction

Tissue adhesives can be used as adjacent to sutures to drop or avoid bleeding in cardiovascular operations.

Objective

To verify the efficiency of fibrin and cyanoacrylate adhesive to seal arterial sutures and if the adhesives penetrate through suture line to the inner of arteries.

Methods

20 abdominal aorta segments of pigs were divided into two groups according to the adhesive which would be used as adjacent to the suture. In every arterial segment an arteriotomy was done, followed by a conventional artery closure. Afterwards a colloidal fluid was injected inside the arterial segment with a simultaneous intravascular pressure monitoring up to a fluid leakage through the suture. This procedure was repeated after application of one of the adhesives on the suture in order to check if the bursting pressure increases. The inner aorta segments also were analyzed in order to check if there was intraluminal adhesive penetration.

Results

In Suture 1 group, the mean arterial pressure sustained by the arterial suture reached 86±5.35 mmHg and after the fibrin adhesive application reached 104±11.96 (P<0.002). In the Suture 2 group, the mean arterial pressure sustained by the suture reached 83±2.67 mmHg and after the cyanoacrylate adhesive application reached 152±14.58 mmHg (P<0.002). Intraluminal adhesive penetration has not been noticed.

Conclusion

There was a significant rise in the bursting pressure when tissue adhesives were used as adjacent to arterial suture, and this rise was higher if the cyanoacrylate adhesive was used. In addition, the adhesives do not penetrate through the suture line into the arteries.

Effectiveness of cyanoacrylate adhesive in rabbit aortorrhaphy

BACKGROUND: Even when properly performed, arterial sutures are not always absolutely hemostatic. Tissue sealants and adhesives have become available that can be used to complete sutures, preventing hemorrhage problems.OBJECTIVES: To evaluate the effectiveness of cyanoacrylate adhesive for sealing aortotomies in rabbits in a coagulopathic state, by analyzing survival of the animals and the time taken to achieve hemostasis.METHODS: Ten-mm long aortotomies were performed on the infrarenal aortas of 12 animals. In four animals, aortorrhaphy was conducted using four interrupted polypropylene sutures and in the remaining animals aortorrhaphy was performed using four or fewer polypropylene stitches, followed by application of a cyanoacrylate adhesive.RESULTS: The four animals sutured without adhesive died within the postoperative period due to severe hemorrhage (3 animals) or intestinal ischemia. The eight animals to which the adhesive was applied exhibited no transoperative bleeding, but one animal died during the postoperative period. Using cyanoacrylate permitted more rapid procedures (p<0.004) and no local reactions were observed in macroscopic examination of tissues.CONCLUSIONS: The cyanoacrylate adhesive demonstrated effectiveness for sealing aortotomies, considering the survival outcomes, duration of procedures and absence of local reactions on macroscopic examination.

[Topical haemostatic agents and tissue adhesives]

In the last ten years the hemostatic agents and tissue adhesives have been frequently used and they are positive alternatives to prevent excessive blood loss. The objective of this review is to discuss the characteristics of each of these agents to facilitate the surgeon's decision when choosing the most suitable product for every type of bleeding and nature of hemorrhage. A survey of the literature on the subject, in English and in Portuguese, was conducted using PubMed (www.pubmed.com) and Google (www.google.com.br) to find recent articles on the topic. Based on these studies, the authors conducted a didactic review on the hemostatic agents and tissue adhesives and concluded that there is a hemostatic agent to be used in each specific scenario.

The use of cyanoacrylate in surgical anastomosis: an alternative to microsurgery

To present anastomosis with cyanoacrylate as a cheap, simple, fast, and available technique for anastomosis in urological, vascular, gynecological, and general surgical procedures. This method may in the future be a good alternative to microsurgery, particularly in centers where facilities are unavailable and the financial implication is unbearable for the patient. Cyanoacrylate is an adhesive or glue that is available in different chemical forms ranging from ethylcyanoacrylate (superglue) to Isobutylcyanoacrylate and octylcyanoacrylate (dermerbond), which is in clinical use. Anastomosis with cyanoacrylate requires the application of stay sutures, a luminal stent and the subsequent application of the adhesive. The adhesives with lower molecular weights produce a rigid and patent region of anastomosis, while the higher molecular compounds produce a consistency close to the normal tissue. This technique presents a surgical method that is socially, culturally, and ethically acceptable, which is affordable to a larger majority of patients in our subregion. Cyanoacrylate anastomosis may in the future present a fast, convenient, simple, and affordable option in the treatment of patients requiring anastomosis. In our subregion where the socio-cultural, psychological, and economic burden of failed anastomosis is high, associated with the low per capital income, this may be a novel option for the management of urogynecological, vascular, neurosurgical, and general surgical procedures requiring either microscopic or macroscopic anastomosis.

Cyanoacrylate surgical glue as an alternative to suture threads for mesh fixation in hernia repair

BACKGROUND

In recent years, the use of synthetic glues has become an established practice in several areas of surgical treatment. For example, they are used in open and laparoscopic surgery and in digestive tract endoscopy, interventional radiology, and vascular neuroradiology. The experiments in this study were aimed at elucidating that suture-based permanent mesh fixation can be replaced by fixation with N-butyl 2-cyanoacrylate glue (Glubran2) for surgical repair of abdominal wall hernias.

MATERIALS AND METHODS

In 25 Wistar rats, two hernia defects (1.5 cm in diameter) per animal were created bilaterally in the midline of the abdominal wall. The peritoneum was spared. The lesions were left untreated for 10 d to achieve a chronic condition. Then the defects were covered with TiMESH extralight (2 × 2 cm) and fixed by 30 μL of Glubran2 or traditional suture. The time points of sacrifice were 17 and 28 d, 3, 4, and 5 mo. At autopsy, histology and immunohistochemistry were performed to evaluate the inflammatory response and the presence of apoptotic cells respectively.

RESULTS

Mesh fixation was excellent in all samples at each time point. At application sites, the inflammatory reaction was mild with a small number of macrophages and vascularized connective tissue presence around glue and mesh threads. Glue residues were observed in histologic sections at each time point. No presence of apoptotic cells was found.

CONCLUSIONS

This study demonstrated that Glubran2 can effectively replace traditional suture in mesh fixation without affecting tissue healing and determining a physiological inflammatory reaction at the abdominal wall site.