Cyanoacrylate for colonic anastomosis; is it safe?

Suture reinforcement using a modified cyanoacrylate glue to prevent anastomotic leak in colorectal surgery: a prospective multicentre randomized trial : The Rectal Anastomotic seaL (ReAL) trial

BACKGROUND

Anastomotic leakage (AL) is the most frequent life-threating complication following colorectal surgery. Several attempts have been made to prevent AL. This prospective, randomized, multicentre trial aimed to evaluate the safety and efficacy of nebulised modified cyanoacrylate in preventing AL after rectal surgery.

METHODS

Patients submitted to colorectal surgery for carcinoma of the high-medium rectum across five high-volume centres between June 2021 and January 2023 entered the study and were randomized into group A (anastomotic reinforcement with cyanoacrylate) and group B (no reinforcement) and followed up for 30 days. Anastomotic reinforcement was performed via nebulisation of 1 mL of a modified cyanoacrylate glue. Preoperative features and intraoperative and postoperative results were recorded and compared. The study was registered at ClinicalTrials.gov (ID number NCT03941938).

RESULTS

Out of 152 patients, 133 (control group, n = 72; cyanoacrylate group, n = 61) completed the follow-up. ALs were detected in nine patients (12.5%) in the control group (four grade B and five grade C) and in four patients (6.6%), in the cyanoacrylate group (three grade B and one grade C); however, despite this trend, the differences were not statistically significant (p = 0.36). However, Clavien-Dindo complications grade > 2 were significantly higher in the control group (12.5% vs. 3.3%, p = 0.04). No adverse effects related to the glue application were reported.

CONCLUSION

The role of modified cyanoacrylate application in AL prevention remains unclear. However its use to seal colorectal anastomoses is safe and could help to reduce severe postoperative complications.

Double-layer adhesives for preventing anastomotic leakage and reducing post-surgical adhesion

Preventing anastomotic leakage (AL) and postoperative adhesions after gastrointestinal surgery is crucial for ensuring a favorable surgical prognosis. However, AL prevention using tissue adhesives can unintentionally lead to undesirable adhesion formation, while anti-adhesive agents may interfere with wound healing and contribute to AL. In this study, we have developed a double-layer patch, consisting of an adhesive layer on one side, utilizing gallic acid-conjugated chitosan (CHI-G), and an anti-adhesive layer on the opposite side, employing crosslinked hyaluronic acid (cHA). These CHI-G/cHA double-layer adhesives significantly prevented AL by forming physical barriers of CHI-G and reduced post-surgical adhesion at the anastomosis sites by the anti-adhesive layers of cHA. The bursting pressure (161.1 ± 21.6 mmHg) of double-layer adhesives-applied rat intestine at postoperative day 21 was far higher than those of the control (129.4 ± 5.7 mmHg) and the commercial anti-adhesives-applied group (120.8 ± 5.2 mmHg). In addition, adhesion score of double-layer adhesives-applied rat intestine was 3.6 ± 0.3 at postoperative day 21, which was similar to that of the commercial anti-adhesives-applied group (3.6 ± 0.3) and lower than that of the control group (4.9 ± 0.5). These findings indicate that the double-layer patch (CHI-G/cHA) has the potential to effectively prevent both postoperative adhesions and anastomotic leakage, offering a promising solution for gastrointestinal surgery.

Colonic Anastomoses Reinforced With Ethyl-2-Cyanoacrylate Compared With Polydioxanone Sutures Alone in Fecal Peritonitis: An Experimental Study in Wistar Rats

INTRODUCTION

The use of tissue adhesives has been proposed as an anastomosis reinforcement; however, their efficacy has not been evaluated in a contaminated environment. The objective of this study was to determine if the use of sutures reinforced with ethyl-2-cyanoacrylate for colonic anastomoses in the presence of fecal peritonitis, in a murine animal model, decreases the frequency of dehiscence.

METHODS

Wistar rats were used. Fecal peritonitis was established until reaching 18 hours of evolution. Then, resection and anastomosis of the colon were performed with only polydioxanone (PDS) sutures in the control group and reinforcement with ethyl-2-cyanoacrylate in the experimental group. The dehiscence frequency and burst pressure were evaluated six days after the anastomosis was performed.

RESULTS

We included 30 Wistar rats, all males, with a median age of five months and an average weight of 350.43 g. Anastomotic dehiscence was observed in 53.33% of the control group, in contrast with 13.33% of the experimental group (p = 0.020). There was no significant difference in burst pressure between the two groups.

CONCLUSION

The use of ethyl-2-cyanoacrylate, in an experimental murine animal model, as reinforcement in colonic anastomoses in the presence of fecal peritonitis decreases the frequency of anastomotic dehiscence, although it does not increase resistance to burst pressure.

Cyanoacrylate in Colorectal Surgery: Is It Safe?

Anastomotic leakage (AL) of a gastrointestinal (GI) anastomosis continues to be an important complication in GI surgery. Since its introduction more than 60 years ago, Cyanoacrylate (CA) has gained popularity in colorectal surgery to provide "prophylaxis" against AL. However, although in surgical practice it is increasingly used, evidence on humans is still lacking. The aim of this study is to analyze in humans the safety of CA to seal colorectal anastomosis. All consecutive patients from Jannuary 2022 through December 2022 who underwent minimally invasive colorectal surgery were retrospectively analyzed from a prospectively maintained database. Inclusion criteria were a histological diagnosis of cancer, a totally minimally invasive procedure, and the absence of intraoperative complications. 103 patients were included in the study; N-butyl cyanoacrylate with metacryloxisulfolane (Glubran 2®) was used to seal colorectal anastomosis, no adverse reactions to CA or postoperative complications related to inflammation and adhesions occurred; and only one case of AL (0.9%) was recorded. We can consider this study an important proof of concept on the safety of CA to seal colorectal anastomosis. It opens the possibility of starting prospective and comparative studies in humans to evaluate the effectiveness of CA in preventing colorectal AL.

Biological Application of Novel Biodegradable Cellulose Composite as a Hemostatic Material

Degradable hemostatic materials have unique advantages in reducing the amount of bleeding, shortening the surgical operation time, and improving patient prognosis. However, none of the current hemostatic materials are ideal and have disadvantages. Therefore, a novel biodegradable cellulose-based composite hemostatic material was prepared by crosslinking sodium carboxymethyl cellulose (CCNa) and hydroxyethyl cellulose (HEC), following an improved vacuum freeze-drying method. The resulting cellulose composite material was neutral in pH and spongy with a density of 0.042 g/cm³, a porosity of 77.68%, and an average pore size of 13.45 μm. The composite's compressive and tensile strengths were 0.1 MPa and 15.2 MPa, respectively. Under in vitro conditions, the composites were degraded gradually through petite molecule stripping and dissolution, reaching 96.8% after 14 days and 100% degradation rate at 21 days. When implanted into rats, the degradation rate of the composite was slightly faster, reaching 99.7% in 14 days and 100% in 21 days. Histology showed a stable inflammatory response and no evidence of cell degeneration, necrosis, or abnormal hyperplasia in the tissues around the embedded material, indicating good biocompatibility. In the hemorrhagic liver model, the time to hemostasis and the total blood loss in the cellulose composite group was significantly lower than in the medical gauze group and the blank control group (P < 0.05). These data indicate that the novel cellulose composite is a promising implantable hemostatic material in clinical settings.

Tissue Adhesives in Reconstructive and Aesthetic Surgery—Application of Silk Fibroin-Based Biomaterials

Tissue adhesives have been successfully used in various kind of surgeries such as oral and maxillofacial surgery for some time. They serve as a substitute for suturing of tissues and shorten treatment time. Besides synthetic-based adhesives, a number of biological-based formulations are finding their way into research and clinical application. In natural adhesives, proteins play a crucial role, mediating adhesion and cohesion at the same time. Silk fibroin, as a natural biomaterial, represents an interesting alternative to conventional medical adhesives. Here, the most commonly used bioadhesives as well as the potential of silk fibroin as natural adhesives will be discussed.

Incorporation of a Poly-ε-Caprolactone Scaffold in a ;Circular Stapled End-To-End Small Intestine Anastomosis Does Not Have Any Adverse Effects Within 30 days: A Study in Piglets

Background. Incorporation of a poly-ε-caprolactone (PCL) scaffold in circular stapled anastomoses has been shown to increase the anastomotic tensile strength on postoperative day (POD) 5 in a pig model. The aim of this study was to investigate the effects of incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis, with stricture formation and anastomotic histology as primary outcomes in a 30-day observation period. Methods. A total of 15 piglets were included. In each piglet, three circular stapled end-to-end anastomoses were made in the small intestines. Two were interventional and one was a control. On POD 10, 20, or 30, the anastomoses were subjected to in vivo intraluminal contrast study, and the index for anastomotic lumen was calculated. The anastomotic segment was resected and subjected to a tensile strength test and histological examination. Results. At POD 10, the mean ± SD value for anastomotic index was .749 ± .065 in control anastomoses and .637 ± .051 in interventional anastomosis (P = .0046), at POD 20, .541 ± .150 and .724 ± .07 (P = .051), and at POD 30, .645 ± .103 and .686 ± .057 (P = .341), respectively. No significant difference was observed in maximum tensile strength and histology at POD 30. Conclusions. The incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis does not increase the risk of stricture or impair wound healing after 30 days.

Electrospun nanofibers as support for the healing of intestinal anastomoses

The breakdown of intestinal anastomosis is a serious postsurgical complication. The worst complication is anastomotic leakage, resulting in contaminated peritoneal cavity, sepsis, multi-organ failure and even death. In problematic locations like the rectum, the leakage rate has not yet fallen below 10 %. Such a life-threatening condition is the result of impaired healing in the anastomotic wound. It is still vital to find innovative strategies and techniques in order to support regeneration of the anastomotic wound. This paper reviews the surgical techniques and biomaterials used, tested or published. Electrospun nanofibers are introduced as a novel and potential material in gastrointestinal surgery. Nanofibers possess several, unique, physical and chemical properties, that may effectively stimulate cell proliferation and collagen production; a key requirement for the healed intestinal wound.

Clinical Feasibility of Large Gastrotomy Closure Using a Flexible Tissue Glue Based on N-Butyl-2-Cyanoacrylate: Experimental Study in Pigs

BACKGROUND

The use of synthetic adhesives such as cyanoacrylates has been established previously for a wide range of clinical indications. However, more research is necessary to evaluate their use in digestive closures or anastomosis. New chemical formulations developed to achieve more flexibility of synthetic adhesives (i.e., based on n-butyl-2-cyanoacrylate) could be an alternative to achieve this purpose. The aim of this study was to investigate the feasibility of using flexible cyanoacrylate adhesives for large gastric incision closure in an animal model.

METHODS

Twelve farm pigs were divided in two groups depending on the type of closure method applied. In all cases, extra-large seven centimeters gastrostomies were performed. Braided absorbable hand-sewn interrupted suture versus n-butyl-2-cyanoacrylate with softener closure were compared during a 3-week follow-up period. Histopathological aspects, hematologic and inflammatory biomarkers, and endoluminal pressure tolerated until leakage were assessed. The time spent on both closing procedures was compared.

RESULTS

No differences between the two groups were found in any of the histopathological and inflammatory variables evaluated. The glued group tolerated a significantly higher pressure than the manual suture group. A reduction of surgery time was also observed.

CONCLUSIONS

Our results suggest that flexible cyanoacrylates could be a feasible alternative to improve the clinical outcome of the closure of hollow viscera through more efficient sutureless procedures.

The effect of three different surgical techniques for colon anastomosis on regional postoperative microperfusion: Laser Doppler Flowmetry study in pigs

BACKGROUND

The optimal surgical approach to reconnecting bowel ends safely after resection is of great importance.

OBJECTIVES

This project is focused on assessment of the perianastomotic microcirculation quality in the short postoperative period when using three different anastomosis techniques in experimental animal.

METHODS

The experimental study involved 27 young female domestic pigs divided into three subgroups of 9 animals according to each surgical method of anastomosis construction in the sigmoid colon region: by manual suture, by stapler, or by gluing. Blood microcirculation in the anastomosis region was monitored using Laser Doppler Flowmetry (LDF). Anastomosis healing was evaluated by macroscopic and histological examination.

RESULTS

Evaluation of the microcirculation in the anastomosis region showed the smallest decrease in perfusion values in animals reconstructed by suturing (Δ= -38.01%). A significantly more profound drop was observed postoperatively after stapling or gluing (Δ= -52.42% and Δ= -59.53%, respectively). All performed anastomoses healed without any signs of tissue and function pathology.

CONCLUSIONS

Sewing, stapling, and gluing techniques for bowel anastomosis each have a different effect on regional microcirculation during 120 min. postoperatively. Nevertheless, the final results of anastomosis healing were found without of any pathology in all experimental animals managed by above mentioned anastomotic techniques.

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.

Sutureless closure of colonic defects with tissue adhesives: an in vivo study in the rat

BACKGROUND

Tissue adhesives (TAs) in gastrointestinal surgery are gradually gaining acceptance. Before implementation as colonic sealants, an evaluation of the sealing capability of a TA when in contact with fecal matter, as in a leaking anastomosis, is needed. In this study, we used clinically available TAs for the sutureless closure of colonic defects evaluating mechanical strength and tissue healing.

METHODS

A total of 160 rats were divided into 8 groups. Two .5-cm incisions were created, one in the proximal and another in the distal colon. Incisions were sealed with a TA: Histoacryl Flex, Bioglue, Dermabond, Tissucol, Duraseal Xact, gelatin-resorcinol-formaldehyde or Glubran 2. A control group was included in which the colonic defects were not sealed. Follow-up time was 3 or 10 days. Clinical complication rate, bursting pressure, and histopathologic analysis was included.

RESULTS

Leakage rates in the TA groups were highest for Duraseal Xact, Bioglue, and gelatin-resorcinol-formaldehyde at 3 and 10 days. The cyanoacrylates Glubran 2, Histoacryl Flex, and Omnex, and the fibrin glue Tissucol showed the lowest overall clinical complication rates while maintaining the highest bursting pressure at day 10. Histoacryl Flex exhibited significantly higher collagen formation at day 10 than the other TAs.

CONCLUSIONS

This experimental model evaluates the protective effect of a TA seal on a leaking colonic defect. We found large differences in leakage rates and inertness of the tested TAs. The cyanoacrylates Histoacryl Flex, Omnex, and Glubran 2 as well as the fibrin glue Tissucol demonstrated the lowest leakage rates and the most inert histopathologic profile while maintaining high mechanical strength.

Introduction of Flexible Cyanoacrylates in Sutureless Gastric Closure

Background Clinical effectiveness and safety of biological and synthetic adhesives in digestive closures have been evaluated. Their use is becoming more prevalent, as rigidity and inflexibility are its more remarkable weaknesses. However, little is known about their role in gastric and anastomotic closures. Moreover, usefulness of novel flexible types of synthetic adhesives as n-butyl-cyanoacrylate has not been assessed yet. Materials and Methods One centimeter long gastrotomy was performed in 24 male Wistar rats, which were divided depending on the type of closure method employed: manual USP 5/0 silk interrupted suture versus sutureless closure with Histoacryl Flexible (n-butyl-cyanoacrylate with softener) or Histoacryl Double Component (n-butyl-cyanoacrylate with softener and hardener). Microscopic evaluation of the suture viability and integrity was performed, and adhesion formation during the cicatrization process were assessed. During an 8-week follow-up clinical and histopathological aspects as well as hematologic and inflammatory biomarkers were studied. Results No differences among groups where found in any of the clinical, analytical, or histopathological issues assessed except for a higher incidence rate of adhesions in the Histoacryl Double Component group when compared with hand-sewn suture group (P = .04). Our results support experimental studies in large mammals (pigs) for further study of sutureless hollow viscera closure.

A cross-linking strategy provides a new generation of biodegradable and biocompatible cyanoacrylate medical adhesives

A general strategy provides a new generation of biodegradable and biocompatible cyanoacrylate medical adhesives.

Fibrinogen and thrombin concentrations are critical for fibrin glue adherence in rat high-risk colon anastomoses

OBJECTIVE

Fibrin glues have not been consistently successful in preventing the dehiscence of high-risk colonic anastomoses. Fibrinogen and thrombin concentrations in glues determine their ability to function as sealants, healers, and/or adhesives. The objective of the current study was to compare the effects of different concentrations of fibrinogen and thrombin on bursting pressure, leaks, dehiscence, and morphology of high-risk ischemic colonic anastomoses using fibrin glue in rats.

METHODS

Colonic anastomoses in adult female Sprague-Dawley rats (weight, 250-350 g) treated with fibrin glue containing different concentrations of fibrinogen and thrombin were evaluated at post-operative day 5. The interventions were low-risk (normal) or high-risk (ischemic) end-to-end colonic anastomoses using polypropylene sutures and topical application of fibrinogen at high (120 mg/mL) or low (40 mg/mL) concentrations and thrombin at high (1000 IU/mL) or low (500 IU/mL) concentrations.

RESULTS

Ischemia alone, anastomosis alone, or both together reduced the bursting pressure. Glues containing a low fibrinogen concentration improved this parameter in all cases. High thrombin in combination with low fibrinogen also improved adherence exclusively in low-risk anastomoses. No differences were detected with respect to macroscopic parameters, histopathology, or hydroxyproline content at 5 days post-anastomosis.

CONCLUSIONS

Fibrin glue with a low fibrinogen content normalizes the bursting pressure of high-risk ischemic left-colon anastomoses in rats at day 5 after surgery.

Critical analysis of cyanoacrylate in intestinal and colorectal anastomosis

BACKGROUND

Although cyanoacrylate glue (CA) has been widely used in various kinds of medical applications, its application in gastrointestinal anastomosis remains limited, and outcomes of experimental studies have not been satisfactory. This systematic review summarizes research regarding CA application in intestinal and colorectal anastomosis, and correlates methodological aspects to experimental outcomes.

METHODS

A systematic literature search was performed using Medline, Embase, Cochrane, and Web-of-Science libraries. Articles were selected if CA was applied to intestinal or colorectal anastomoses. Included articles were categorized according to CA molecular structure; the method details in each study were extracted and analyzed.

RESULTS

Twenty-two articles were included. More than half of the inclusions reported positive outcomes (seven articles) or neutral outcomes (eight articles). Analysis of the methods revealed that methodological details such as CA dosage, time of polymerization were not consistently reported. Porcine studies, inverted anastomosis, and n-butyl-cyanoacrylate studies showed more positive outcomes; everted anastomosis, and oversized sutures might negatively influence the outcomes.

CONCLUSIONS

Owing to the positive outcome from the porcine studies, application of CA in gastrointestinal (GI) anastomosis still seems promising. To achieve a better consistency, more methodological details need to be provided in future studies. Optimizing the dosage of CA, choice of animal model, inverted anastomosis construction, and other method details may improve intestinal and colorectal anastomoses with CA application in future studies.

All the commercially available adhesion barriers have the same effect on adhesion prophylaxis?; A comparison of barrier agents using a newly developed, severe intra-abdominal adhesion model

BACKGROUND

Various types of adhesion barriers are widely used to prevent intra-abdominal adhesion. However, few studies have compared the efficacy of adhesion barriers using the same animal model. The aim of this study was to compare the anti-adhesive effects of various barrier agents using a newly developed, severe adhesion model.

METHODS

A severe adhesion model was established by excision of a 1-cm(2) intra-abdominal wall and application of cyanoacrylate in rat. Eighty male Sprague-Dawley rats (10 weeks old; 370 ± 50 g) were divided randomly into four groups (n = 20 each): the untreated control group, G-group using a hyaluronic acid and sodium carboxymethyl cellulose gel (Guardix-sol®), A-group using 4% icodextrin (Adept®), and S-group using a hyaluronate-carboxymethyl cellulose membrane (Seprafilm®). The effect of each adhesion barrier was evaluated by means of the extent and severity of adhesion, difficulty of adhesiolysis scoring systems, and microscopic grade of fibrosis.

RESULTS

The G-group showed no difference in adhesion score and fibrosis, the A-group demonstrated only a significantly lower fibrosis, and the S-group exhibited a significantly lower adhesion score and lower fibrosis compared with the control group. The S-group had a significantly lower adhesion score and reduced fibrosis compared with the G-group; however, no significant difference in adhesion score and fibrosis was noted with the A-group.

CONCLUSIONS

The membranous barrier Seprafilm® may be effective in the prevention of adhesion in the condition of peritoneal injury combined with foreign material. Adept® showed a tendency of decreasing the severity of adhesion and was effective in the prevention of fibrosis.

Reducing anastomotic leakage by reinforcement of colorectal anastomosis with cyanoacrylate glue

INTRODUCTION

Technical failure of sutured or stapled anastomoses may lead to anastomotic leakage, which is one of the most important complications after colorectal surgery. Cyanoacrylate glue (CA) provides strong mechanical attachment, making it a good candidate for suture reinforcement. This study aimed to demonstrate that CA is the most important factor in the strength of a sealed colorectal anastomosis, in both normal and insufficient anastomoses.

METHODS

Ex vivo porcine colorectal segments were resected. A 1-layer continuous anastomosis or an insufficient 6-interrupted-suture anastomosis was created, and the baseline anastomotic bursting pressure (ABP) was measured. The primary anastomosis was then reinforced either by CA or with 4 additional interrupted sutures, further inverting the anastomosis. After reinforcement a second ABP test was performed.

RESULTS

Thirty-two segments were used. Reinforcing the anastomosis by CA significantly increased ABP in both normal and insufficient anastomoses when compared to the primary anastomosis (p < 0.05 for all groups); no significant difference in ABP was found between normal and insufficient anastomosis groups after CA reinforcement. Anastomotic reinforcement with CA was not inferior to the reinforcement with sutures in both normal and insufficient anastomoses, and had significantly fewer ABP variances in normal anastomosis groups (p = 0.042).

CONCLUSION

Reinforcing a colorectal anastomosis with CA increases its mechanical strength in both normal and technically insufficient situations, which may contribute to the reduction of anastomotic leakage. CA is promising for anastomotic reinforcement based on mechanical improvement of the anastomosis, and in vivo studies are needed to evaluate its biological effects.

Prevention of leakage by sealing colon anastomosis: experimental study in a mouse model

BACKGROUND

In colorectal surgery, anastomotic leakage (AL) is the most significant complication. Sealants applied around the colon anastomosis may help prevent AL by giving the anastomosis time to heal by mechanically supporting the anastomosis and preventing bacteria leaking into the peritoneal cavity. The aim of this study is to compare commercially available sealants on their efficacy of preventing leakage in a validated mouse model for AL.

METHODS

Six sealants (Evicel, Omnex, VascuSeal, PleuraSeal, BioGlue, and Colle Chirurgicale Cardial) were applied around an anastomosis constructed with five interrupted sutures in mice, and compared with a control group without sealant. Outcome measures were AL, anastomotic bursting pressure, and death.

RESULTS

In the control group there was a 40% death rate with a 50% rate of AL. None of the sealants were able to diminish the rate of AL. Furthermore, use of the majority of sealants resulted in failure to thrive, increased rates of ileus, and higher mortality rates.

CONCLUSIONS

If sealing of a colorectal anastomosis could achieve a reduction of incidence of clinical AL, this would be a promising tool for prevention of leakage in colorectal surgery. In this study, we found no evidence that sealants reduce leakage rates in a mouse model for AL. However, the negative results of this study make us emphasize the need of systemic research, investigating histologic tissue reaction of the bowel to different sealants, the capacity of sealants to form a watertight barrier, their time of degradation, and finally their results in large animal models for AL.

Tissue adhesives in gastrointestinal anastomosis: a systematic review

BACKGROUND

Anastomotic leakage in gastrointestinal (GI) surgery remains a major problem. Although numerous studies have been undertaken on the role of tissue adhesives as GI anastomotic sealants, no clear overview has been presented. This systematic review aims to provide a clear overview of recent experimental and clinical research on the sealing of different levels of GI anastomosis with tissue adhesives.

METHODS

We searched MEDLINE and Embase databases for clinical and experimental articles published after 2000. We included articles only if these addressed a tissue adhesive applied around a GI anastomosis to prevent anastomotic leakage or decrease leakage-related complications. We categorized results according to level of anastomosis, category of tissue adhesive, and level of evidence.

RESULTS

We included 48 studies: three on esophageal anastomosis, 13 on gastric anastomosis, four on pancreatic anastomosis, eight on small intestinal anastomosis, and 20 on colorectal anastomosis; 15 of the studies were on humans.

CONCLUSIONS

Research on ileal and gastric/bariatric anastomosis reveals promising results for fibrin glue sealing for specific clinical indications. Sealing of pancreatico-enteric anastomosis does not seem to be useful for high-risk patients; however, research in this field is limited. Ileal anastomotic sealing was promising in every included study, and calls for clinical evaluation. For colorectal anastomoses, sealing with fibrin glue sealing seems to have more positive results than with cyanoacrylate. Further research should concentrate on the clinical evaluation of promising experimental results as well as on new types of tissue adhesives. This research field would benefit from a systematic experimental approach with comparable methodology.

External coating of colonic anastomoses: a systematic review

PURPOSE

Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic anastomoses.

METHODS

CINAHL, EMBASE, and PubMed were searched up to September 2011 to identify studies evaluating external coating of colonic anastomoses.

RESULTS

Forty studies have evaluated 20 different coating materials, of which only fibrin sealant, omental pedicle graft, and hyaluronic acid/carboxymethylcellulose have been used in humans. Fibrin sealant has shown positive, however not significant, results. Omental pedicle graft can be used safely, yet without beneficial effects, whereas hyaluronic acid/carboxymethylcellulose should be avoided due to increased complications. The remaining coating materials have solely been evaluated in experimental animals with many contradictory and few positive results.

CONCLUSIONS

External coating of colonic anastomoses has yet failed to show convincing results. Randomized clinical trials and high-quality experimental studies are warranted to determine the role of fibrin sealant, omental pedicle graft, and other coating materials for prevention of colon anastomotic leakage.

Adipose-tissue-derived Stem Cells Enhance the Healing of Ischemic Colonic Anastomoses: An Experimental Study in Rats

Purpose

This experimental study verified the effect of adipose-tissue-derived stem cells (ASCs) on the healing of ischemic colonic anastomoses in rats.

Methods

ASCs were isolated from the subcutaneous fat tissue of rats and identified as mesenchymal stem cells by identification of different potentials. An animal model of colonic ischemic anastomosis was induced by modifying Nagahata's method. Sixty male Sprague-Dawley rats (10-week-old, 370 ± 50 g) were divided into two groups (n = 30 each): a control group in which the anastomosis was sutured in a single layer with 6-0 polypropylene without any treatment and an ASCtreated group (ASC group) in which the anastomosis was sutured as in the control group, but then ASCs were locally transplanted into the bowel wall around the anastomosis. The rats were sacrificed on postoperative day 7. Healing of the anastomoses was assessed by measuring loss of body weight, wound infection, anastomotic leakage, mortality, adhesion formation, ileus, anastomotic stricture, anastomotic bursting pressure, histopathological features, and microvascular density.

Results

No differences in wound infection, anastomotic leakage, or mortality between the two groups were observed. The ASC group had significantly more favorable anastomotic healing, including less body weight lost, less ileus, and fewer ulcers and strictures, than the control group. ASCs augmented bursting pressure and collagen deposition. The histopathological features were significantly more favorable in the ASC group, and microvascular density was significantly higher than it was in the control group.

Conclusion

Locally-transplanted ASCs enhanced healing of ischemic colonic anastomoses by increasing angiogenesis. ASCs could be a novel strategy for accelerating healing of colonic ischemic risk anastomoses.

Protection of intestinal anastomosis with biological glues: an experimental randomized controlled trial

BACKGROUND

The aim of the study was to compare the degree of healing and air tightness of hand-sewn colonic anastomoses provided by different biological glues.

METHODS

Thirty colonic anastomoses were fashioned in ten rabbits, at 5, 10, 15 cm from the ileocecal valve, with 4/0 PDS running sutures. Each suture was randomized to treatment with fibrin sealant (Tissucol®), a synthetic glue (Coseal®), or nothing (control). After 15 days, the rabbits were killed and the anastomoses examined for their integrity and resistance to bursting. The van der Hamm scale was used to evaluate postoperative adhesions. A blind histological evaluation of the newly formed tissue was made (Ehrlich-Hunt scale).

RESULTS

Two rabbits developed an intraabdominal abscess, one in the control anastomosis group without glue. Postoperative adhesions were present in all animals. Median anastomosis bursting pressures were 0.9 atm in all three groups: Tissucol, Coseal, and control. Pressure values were 0.9, 1.0, and 0.9 atm in the three different proximodistal sites, respectively. A trend toward an increased resistance was observed in the glued anastomosis, although this was not significant. Lymphocyte infiltration, fibroblast activity, blood vessel density, and collagen deposition were lower in controls. Anastomoses treated with Tissucol had the highest lymphocyte infiltration level. The Coseal group developed the highest rates of fibroblast activity, collagen deposition, and blood vessel neogenesis.

CONCLUSION

The use of biological glues did not result in a statistically significantly increased bursting resistance. Histological evaluation demonstrated more intense tissue neoformation in the glue groups, particularly in the Coseal group. The role of biological glues in decreasing the leakage rate of intestinal anastomoses is uncertain, and larger trials using different protective agents are warranted.