Tissue adhesives in gastrointestinal anastomosis: a systematic review

A pilot study on endoscopic delivery of injectable bioadhesive for esophageal repair in a porcine model

Endoscopic submucosal dissection (ESD) is the gold-standard surgical procedure for superficial esophageal cancer. A significant and challenging complication of this technique is post-ESD esophageal stricture. In this study, the feasibility of endoscopic catheter delivery of bioadhesive to esophageal lesions in a porcine model was tested. Injectable bioadhesive was composed of oxidized dextran (ODA) and chitosan hydrochloride (CS), its physicochemical properties, injectability, antibacterial activity, and cytocompatibility were investigated beforein vivotest. ODA-CS bioadhesive was delivered to the wound bed of the esophageal tissue using a custom-made catheter device after ESD in a porcine model. Our results show that the ODA-CS bioadhesive is of good injectability, tissue adhesive strength, antibacterial capacity, and blood compatibility.In vivodelivery was achieved by endoscopic spraying of ODA and CS in separate catheters fixed on the endoscopic probe. ODA and CS can be mixed well to allow in situ bioadhesive formation and firmly adhere to the esophageal wound surface. After two weeks, the bioadhesive maintained structural integrity and adhered to the surface of esophageal wounds. However, histological analysis reveals that the ODA-CS bioadhesive did not show improvement in attenuating inflammatory response after ESD. This pilot study demonstrates the feasibility of ODA-CS bioadhesive for shielding esophageal wounds after ESD, whereas efforts need to improve its anti-inflammatory activity to reduce fibrosis for stricture prevention.

Clinical results after external reinforcement of colorectal anastomosis: a systematic review

OBJECTIVE

The aim of this review is to describe and assess the existing methods to cover colorectal anastomoses with biomaterials and their clinical impact in reducing anastomotic leakage (AL).

SUMMARY BACKGROUND DATA

The most serious complication in colorectal surgery is AL. Despite improvements in its diagnosis and management, AL remains an unresolved issue. To prevent its appearance and clinical consequences, different external reinforcement techniques with synthetic or biomaterials have been described.

METHODS

A systematic review search of the available literature until June 2022 was performed, looking for all literature regarding external reinforcement of colonic or colorectal anastomoses. After the review process, a classification of materials was proposed into solid and liquid materials, and an assessment of their clinical impact was performed. The study protocol has been registered at PROSPERO and has been reported in the line with PRISMA and AMSTAR Guidelines 11,12 .

RESULTS

Ninety-seven articles that fulfilled inclusion criteria, were identified and revised. Overall, 18 of the selected articles focused on human clinical trials and 79 on animal models. Only fibrin sealants, collagen patches, and omentoplasty have shown positive results in humans.

CONCLUSIONS

Fibrin sealants, collagen patches, and omentoplasty are, so far, the most studied biomaterials. However, further studies are required to confirm these findings before definite recommendations can be made.

The role of tissue adhesives and sealants in colorectal anastomotic healing-a scoping review

PURPOSE

Anastomotic leakage (AL) after colorectal resection is a serious postoperative complication with grave consequences for patients. Despite several efforts to reduce its incidence, AL is still seen among 2-20% of colorectal cancer patients receiving an anastomosis. The use of tissue adhesives and sealants as an extra layer of protection around the anastomosis has shown promising results. We conducted a scoping review to provide an overview of the current knowledge on the effect of tissue adhesives and sealants on colorectal anastomosis healing, as well as their effect on the postoperative outcome.

METHODS

The databases of PubMed, Embase, and Cochrane Library were systematically searched on 14/10/2022. Studies addressing the use of a tissue adhesive or tissue sealant applied around a colorectal anastomosis, with the goal to prevent AL or to decrease AL-related complications, were included. We presented an overview of the available studies and summarized their results narratively.

RESULTS

Seven studies were included out of the 846 screened. All authors reported the rate of AL in their interventions group. Five of the studies found a decreased rate of AL compared to the control group. One study had no incidences of AL, while the last study had a seemingly low rate of AL but no comparison group. Information on secondary outcomes was sparingly reported, but the results hinted at a positive effect.

CONCLUSION

Tissue adhesives and sealants might have a beneficial effect on colorectal anastomosis healing. The literature is sparse, and this review has shown the need for further clinical studies.

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.

Effect of Chitosan on Rheological, Mechanical, and Adhesive Properties of Pectin-Calcium Gel

In the present study, chitosan was included in the pectin ionotropic gel to improve its mechanical and bioadhesive properties. Pectin-chitosan gels P-Ch0, P-Ch1, P-Ch2, and P-Ch3 of chitosan weight fractions of 0.00, 0.25, 0.50, and 0.75 were prepared and characterized by dynamic rheological tests, penetration tests, and serosal adhesion ex vivo assays. The storage modulus (G') and loss modulus (G″) values, gel hardness, and elasticity of P-Ch1 were significantly higher than those of P-Ch0 gel. However, a further increase in the content of chitosan in the gel significantly reduced these parameters. The inclusion of chitosan into the pectin gel led to a decrease in weight and an increase in hardness during incubation in Hanks' solution at pH 5.0, 7.4, and 8.0. The adhesion of P-Ch1 and P-Ch2 to rat intestinal serosa ex vivo was 1.3 and 1.7 times stronger, whereas that of P-Ch3 was similar to that of a P-Ch0 gel. Pre-incubation in Hanks' solution at pH 5.0 and 7.4 reduced the adhesivity of gels; however, the adhesivity of P-Ch1 and P-Ch2 exceeded that of P-Ch0 and P-Ch3. Thus, serosal adhesion combined with higher mechanical stability in a wide pH range appeared to be advantages of the inclusion of chitosan into pectin gel.

Advances in Hydrogel Adhesives for Gastrointestinal Wound Closure and Repair

Millions of individuals undergo gastrointestinal (GI) tract surgeries each year with common postoperative complications including bleeding, perforation, anastomotic leakage, and infection. Today, techniques such as suturing and stapling seal internal wounds, and electrocoagulation stops bleeding. These methods induce secondary damage to the tissue and can be technically difficult to perform depending on the wound site location. To overcome these challenges and to further advance wound closure, hydrogel adhesives are being investigated to specifically target GI tract wounds because of their atraumatic nature, fluid-tight sealing capability, favorable wound healing properties, and facile application. However, challenges remain that limit their use, such as weak underwater adhesive strength, slow gelation, and/or acidic degradation. In this review, we summarize recent advances in hydrogel adhesives to treat various GI tract wounds, with a focus on novel material designs and compositions to combat the environment-specific challenges of GI injury. We conclude with a discussion of potential opportunities from both research and clinical perspectives.

Bridging wounds: tissue adhesives' essential mechanisms, synthesis and characterization, bioinspired adhesives and future perspectives

Bioadhesives act as a bridge in wound closure by forming an effective interface to protect against liquid and gas leakage and aid the stoppage of bleeding. To their credit, tissue adhesives have made an indelible impact on almost all wound-related surgeries. Their unique properties include minimal damage to tissues, low chance of infection, ease of use and short wound-closure time. In contrast, classic closures, like suturing and stapling, exhibit potential additional complications with long operation times and undesirable inflammatory responses. Although tremendous progress has been made in the development of tissue adhesives, they are not yet ideal. Therefore, highlighting and summarizing existing adhesive designs and synthesis, and comparing the different products will contribute to future development. This review first provides a summary of current commercial traditional tissue adhesives. Then, based on adhesion interaction mechanisms, the tissue adhesives are categorized into three main types: adhesive patches that bind molecularly with tissue, tissue-stitching adhesives based on pre-polymer or precursor solutions, and bioinspired or biomimetic tissue adhesives. Their specific adhesion mechanisms, properties and related applications are discussed. The adhesion mechanisms of commercial traditional adhesives as well as their limitations and shortcomings are also reviewed. Finally, we also discuss the future perspectives of tissue adhesives.

Mussel‐Inspired Biomaterials: From Chemistry to Clinic

After several billions of years, nature still makes decisions on its own to identify, develop, and direct the most effective material for phenomena/challenges faced. Likewise, and inspired by the nature, we learned how to take steps in developing new technologies and materials innovations. Wet and strong adhesion by Mytilidae mussels (among which Mytilus edulis—blue mussel and Mytilus californianus—California mussel are the most well‐known species) has been an inspiration in developing advanced adhesives for the moist condition. The wet adhesion phenomenon is significant in designing tissue adhesives and surgical sealants. However, a deep understanding of engaged chemical moieties, microenvironmental conditions of secreted proteins, and other contributing mechanisms for outstanding wet adhesion mussels are essential for the optimal design of wet glues. In this review, all aspects of wet adhesion of Mytilidae mussels, as well as different strategies needed for designing and fabricating wet adhesives are discussed from a chemistry point of view. Developed muscle‐inspired chemistry is a versatile technique when designing not only wet adhesive, but also, in several more applications, especially in the bioengineering area. The applications of muscle‐inspired biomaterials in various medical applications are summarized for future developments in the field.

VIVOSTAT ® SYSTEM AS A METHOD OF PREVENTING ANASTOMOTIC LEAKAGE FOLLOWING LOW ANTERIOR RECTAL RESECTION: CLINICAL CASE

Background: According to current literature, anastomosis leakage holds a leading position among all complications of colorectal surgery. A particular area of prevention of this complication in colorectal oncology is the research of the possibilities of using biological adhesive compounds as a universal biological and mechanical barrier to the spread of intraluminal microflora and tumor cells.

Clinical case: A 65-year-old patient (female) was hospitalized with a diagnosis of rectal cancer cT3cN1cM0 (stage III) after neoadjuvant chemoradiotherapy. Surgical treatment was performed: the laparoscopic low anterior resection of the rectum with expanded lymphodissection, protective loop ileostomy. The anastomosis was formed at a height of 4 cm from the anus. Intraoperatively, the anastomosis line was strengthened using the Vivostat R system product. The technology of on-site preparation and application of the compound is described in the paper.. The postoperative period passed without complications.

Conclusion: Due to the possible economic, oncological and postoperative advantages, the use of modern fibrin adhesive compositions is quite promising for introduction into surgical practice. It is required to conduct research aimed at studying the effectiveness of this method of preventing the leakage of colorectal anastomoses.

Randomized Single-Center Study of Effectiveness and Safety of a Resorbable Lysine-Based Urethane Adhesive for a Drain-Free Closure of the Abdominal Donor Site in a DIEP Flap Breast Reconstruction Procedure

OBJECTIVE

The hypothesis of this parallel group randomized trial testifies if TissuGlu is a safe and an effective alternative to the conventional drainage placement in regard to post-operative fluid management in the abdominal donor site for autologous (DIEP flap) breast reconstruction with a higher postoperative patient quality of life.

PATIENTS AND METHODS

Data was collected for 58 women who required to be at min.18 years old with a BMI < 30 and not taking any SSRIs (Selective Serotonin Reuptake Inhibitors).Exclusion criteria: Discharge with indwelling suction drains at the abdominal site or signs of wound infection during hospital stay.The patients were randomized into a study group (donor site closure with application of surgical adhesive without drains) and a control group (donor site closure with drains) using a randomly sorted sealed envelope system.Th e primary outcome was defined as the number of post-operative seroma formations.The secondary endpoint was the evaluation of patient satisfaction with both methods.

RESULTS

58 patients underwent a DIEP reconstruction (29 in the control- and 29 in the study group).Both groups were homogenous. Rate of seroma was 17%(5/29) in the study group and 10%(3/29) in the control group which showed no statistical significance (p-value = 0.71).Smoking and previous abdominal surgery turned out to be a risk factor for seroma formation in the study group.Overall satisfaction was evaluated with a questionnaire and was higher in the study group.

CONCLUSION

The abdominal closure with the surgical adhesive seems to be a safe procedure that contributes to patient satisfaction and increases the independence upon discharge in patients with adequate inclusion criteria.

An off-the-shelf bioadhesive patch for sutureless repair of gastrointestinal defects

Surgical sealing and repair of injured and resected gastrointestinal (GI) organs are critical requirements for successful treatment and tissue healing. Despite being the standard of care, hand-sewn closure of GI defects using sutures faces limitations and challenges. In this work, we introduce an off-the-shelf bioadhesive GI patch capable of atraumatic, rapid, robust, and sutureless repair of GI defects. The GI patch integrates a nonadhesive top layer and a dry, bioadhesive bottom layer, resulting in a thin, flexible, transparent, and ready-to-use patch with tissue-matching mechanical properties. The rapid, robust, and sutureless sealing capability of the GI patch is systematically characterized using ex vivo porcine GI organ models. In vitro and in vivo rat models are used to evaluate the biocompatibility and degradability of the GI patch in comparison to commercially available tissue adhesives (Coseal and Histoacryl). To validate the GI patch's efficacy, we demonstrate successful sutureless in vivo sealing and healing of GI defects in rat colon, stomach, and small intestine as well as in porcine colon injury models. The proposed GI patch provides a promising alternative to suture for repair of GI defects and offers potential clinical opportunities for the repair of other organs.

Stem cell therapy applied for digestive anastomosis: Current state and future perspectives

BACKGROUND

Digestive tract resections are usually followed by an anastomosis. Anastomotic leakage, normally due to failed healing, is the most feared complication in digestive surgery because it is associated with high morbidity and mortality. Despite technical and technological advances and focused research, its rates have remained almost unchanged the last decades. In the last two decades, stem cells (SCs) have been shown to enhance healing in animal and human studies; hence, SCs have emerged since 2008 as an alternative to improve anastomoses outcomes.

AIM

To summarise the published knowledge of SC utilisation as a preventative tool for hollow digestive viscera anastomotic or suture leaks.

METHODS

PubMed, Science Direct, Scopus and Cochrane searches were performed using the key words “anastomosis”, “colorectal/colonic anastomoses”, “anastomotic leak”, “stem cells”, “progenitor cells”, “cellular therapy” and “cell therapy” in order to identify relevant articles published in English and Spanish during the years of 2000 to 2021. Studies employing SCs, performing digestive anastomoses in hollow viscera or digestive perforation sutures and monitoring healing were finally included. Reference lists from the selected articles were reviewed to identify additional pertinent articles.

Given the great variability in the study designs, anastomotic models, interventions (SCs, doses and vehicles) and outcome measures, performing a reliable meta-analysis was considered impossible, so we present the studies, their results and limitations.

RESULTS

Eighteen preclinical studies and three review papers were identified; no clinical studies have been published and there are no registered clinical trials. Experimental studies, mainly in rat and porcine models and occasionally in very adverse conditions such as ischaemia or colitis, have been demonstrated SCs as safe and have shown some encouraging morphological, functional and even clinical results. Mesenchymal SCs are mostly employed, and delivery routes are mainly local injections and cell sheets followed by biosutures (sutures coated by SCs) or purely topical. As potential weaknesses, animal models need to be improved to make them more comparable and equivalent to clinical practice, and the SC isolation processes need to be standardised. There is notable heterogeneity in the studies, making them difficult to compare. Further investigations are needed to establish the indications, the administration system, potential adjuvants, the final efficacy and to confirm safety and exclude definitively oncological concerns.

CONCLUSION

The future role of SC therapy to induce healing processes in digestive anastomoses/sutures still needs to be determined and seems to be currently far from clinical use.

The Contribution of a Collagen Patch Coated With Fibrin Glue in Sealing Upper Gastrointestinal Defects: An Experimental Study

BACKGROUND/AIM

We aimed to evaluate the safety and efficacy of sealing primary upper gastrointestinal (GI) perforations with a collagen patch coated with fibrin glue (Tachosil^®).

MATERIALS AND METHODS

Thirty New Zealand rabbits were used in this study. An iatrogenic gastric perforation was created, and primary repair was performed on the control group. Tachosil^®, without suturing the deficit, was used in the intervention group.

RESULTS

Leakage was observed in 3 (20%) and 2 rabbits (13.3%) in the control and intervention group, respectively; however, the difference was not statistically significant (p=0.62). Moreover, adhesions formed in 10/15 and all rabbits in the intervention and control group, respectively (p=0.014); however, based on the Zuhlke adhesion's classification, there was no statistically significant difference between the two groups.

CONCLUSION

A collagen patch coated with fibrin glue is not a replacement but can be considered a safe option for the reinforcement of suturing, preventing leakages in the upper GI tract.

Reinforcement of rectal anastomoses with a collagen-based haemostatic patch: a case series report

In this case series report of 10 colorectal cancer patients, a polyethylene glycol-coated collagen-based haemostatic patch was applied after rectal resection to reinforce rectal anastomoses and reduce anastomotic leakage. Patients underwent rectal resection and anastomoses were stapled in place. The patch—Hemopatch®—was applied to 75% of the anastomotic circumference. The surgeon judged the simplicity of application using a reinforcement of rectal anastomosis score. Mean age of patients was 68.1 (range 50–94) years. The patch was successfully applied in eight patients; in seven patients, patch application was straightforward or only slightly complex, according to the reinforcement of rectal anastomosis score. Seven of eight patients experienced no leakage or signs of stricture 6 weeks post-surgery. All patients underwent radical resection. It is possible to apply Hemopatch® during colorectal surgery. However, the patch application procedure needs to be standardized and efficacy needs to be evaluated by conducting larger clinical studies.

Evaluation of Fibrin Sealant in Prevention of Cervical Anastomotic Leakage After McKeown Esophagectomy: A Single-Center, Retrospective Study

BACKGROUND

Anastomotic leakage remains an issue after esophagectomy for patients with esophageal or esophagogastric junction cancer. Previous studies have indicated that the intraoperative application of fibrin sealant may reduce the incidence of postoperative anastomotic leakage. This retrospective study was aimed to evaluate the efficacy and safety of fibrin sealant in the prevention of anastomotic leakage in patients undergoing McKeown esophagectomy.

METHODS

We designed a single-center, retrospective study. Between January 2018 and December 2019, 227 patients with esophageal or esophagogastric junction cancer undergoing McKeown esophagectomy performed by our team were retrospectively identified, of whom 86 patients were included in the FS group and 141 patients were included in the control group. Intraoperatively, 2.5 ml of porcine fibrin sealant was applied circumferentially to the cervical anastomosis after the anastomosis was created in the FS group. The primary outcome was the incidence of cervical anastomotic leakage within the first three months after surgery.

RESULTS

The differences in baseline clinical characteristics between the two groups were not significant except for a history of drinking. In the FS group, the postoperative cervical anastomotic leakage rate was lower (FS group: 4.7% [4 of 82] vs. control group: 19.9% [28 of 141], p < 0.01). Multivariate logistic regression showed that the intraoperative application of fibrin sealant was an independent protective factor for anastomotic leakage (OR 0.169, 95% CI 0.055-0.515, p = 0.002).

CONCLUSIONS

The intraoperative application of fibrin sealant could possibly prevent cervical anastomotic leakage after McKeown esophagectomy with satisfactory safety. Further prospective clinical trials are warranted.

Human fibrinogen and thrombin patch for extraluminal protection of intestinal anastomosis

In spite of recent advances regarding equipment and surgical techniques in colorectal surgery, rates of anastomotic dehiscence (AD) have remained stable throughout the years. The development of products to protect anastomosis aiming the reduction of AD rates has shown to be promising. Human fibrinogen and thrombin patch (HFTP Tachosil®) have been used in experimental studies in animals and small case series in humans, with promising results. In this study, the authors describe the technique of HFTP use in details, aiming the protection of colorectal anastomosis, and retrospectively demonstrate the preliminary results in a pilot case series. HFTP was used in 4 patients submitted to conventional surgery. The procedures performed were: left colon resection, segmental colectomy (both for colorectal cancer), enteral anastomosis for fistula closure and right ileocolectomy. Anastomotic healing and absence of complications were observed in 3 patients, and the patient submitted to right ileocolectomy developed AD and died after reoperation. The use of HFTP is safe and can be indicated in selected cases. However, AD can occur even after the use of this strategy. Randomized controlled trials with larger samples of patients are needed in order to properly define the real benefits of this strategy in dehiscence prevention

Polymeric Tissue Adhesives

Polymeric tissue adhesives provide versatile materials for wound management and are widely used in a variety of medical settings ranging from minor to life-threatening tissue injuries. Compared to the traditional methods of wound closure (i.e., suturing and stapling), they are relatively easy to use, enable rapid application, and introduce minimal tissue damage. Furthermore, they can act as hemostats to control bleeding and provide a tissue-healing environment at the wound site. Despite their numerous current applications, tissue adhesives still face several limitations and unresolved challenges (e.g., weak adhesion strength and poor mechanical properties) that limit their use, leaving ample room for future improvements. Successful development of next-generation adhesives will likely require a holistic understanding of the chemical and physical properties of the tissue-adhesive interface, fundamental mechanisms of tissue adhesion, and requirements for specific clinical applications. In this review, we discuss a set of rational guidelines for design of adhesives, recent progress in the field along with examples of commercially available adhesives and those under development, tissue-specific considerations, and finally potential functions for future adhesives. Advances in tissue adhesives will open new avenues for wound care and potentially provide potent therapeutics for various medical applications.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model

Introduction

Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery.

Materials and methods

112 adult (8–10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups.

Results

Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats.

Conclusions

Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

The Effect of TISSEEL® on Colorectal Anastomosis Healing Process in a Diabetic Animal Experimental Model

BACKGROUND/AIM

Diabetes mellitus is an established risk factor of colorectal anastomosis failure. The purpose of the present study was to evaluate the effect of TISSEEL® in anastomotic healing.

MATERIALS AND METHODS

Forty male, Sprague-Dawley rats were used. Diabetes was induced in half of them by intraperitoneal injection of Streptozotocin, 60 mg/kg. One week after the injection, animals were operated and a 1 cm segment was removed and an end-to-end hand sewn anastomosis was performed. TISSEEL® was applied in each group (diabetic, non-diabetic) following randomization.

RESULTS

The pathology analysis revealed improved tissue remodeling in the TISSEEL® group, both for the normoglycemic and the diabetic group. Specifically, the extent of inflammation was decreased (p<0.001), whereas fibroblast and collagen formation were improved (p=0.040 and p=0.008). Neovascularization was also improved (p=0.047).

CONCLUSION

Application of TISSEEL® on colorectal anastomoses improves healing in rats that suffer from severe hyperglycemia.

Advances in Topical Hemostatic Agent Therapies: A Comprehensive Update

Severe hemorrhage causes significant metabolic and cellular dysfunction secondary to deficient tissue perfusion and oxygen delivery. If bleeding continues, hemodynamic destabilization, hypoxemia, multiple organ failure, and death will occur. Techniques employed to promote hemostasis include surgical suture ligatures, cautery, chemical agents, self-assembling nanoparticles, and physical methods, like mechanical pressure. Improved understanding of the natural clotting cascade has allowed newly designed agents to become more targeted for clinical and military use. Topically-applied hemostatic agents have enormous clinical applications in achieving hemostasis. This manuscript describes currently available and developing topical hemostatic materials, including topical active agents, mechanical agents, synthetic/hemisynthetic hemostatic agents, and external hemostatic dressings for clinical practice.

Innovative approaches for induction of gastrointestinal anastomotic healing: an update on experimental and clinical aspects

PURPOSE

In most cases, traditional techniques to perform an anastomosis following gastrointestinal resections lead to successful healing. However, despite focused research in the field, in certain high-risk situations leakage rates remain almost unchanged. Here, additional techniques may help the surgeon to protect the anastomosis and prevent leakage. We give an overview of some of the latest developments on experimental and clinical techniques for induction of anastomotic healing.

METHODS

We performed a review of the current literature on approaches to improve anastomotic healing.

RESULTS

Many promising approaches with a high clinical potential are in the developmental pipeline. Highly experimental approaches like inhibition of matrix metalloproteinases, stem cell therapy, hyperbaric oxygen therapy, induction of the hypoxic adaptive response, and the administration of growth factors are still in the preclinical phase. Other more clinical developments aim to strengthen the anastomotic suture line mechanically while shielding it from the influence of the microbiome. Among them are gluing, seaming the staple line, attachment of laminar biomaterials, and temporary intraluminal tubes. In addition, individualized bowel preparation, selectively reducing certain detrimental microbial populations could become the next stage of bowel preparation. Compression anastomoses are evolving as an equivalent technique additional to established hand-sewn and stapled anastomoses. Fluorescence angiography and flexible endoscopy could complement intraoperative quality control additionally to the air leak tests. Virtual ileostomy is a concept to prepare the bowel for the easy formation of a stoma in case of leakage.

CONCLUSION

A variety of promising diagnostic and prophylactic measures that may support the surgeon in identifying high-risk anastomoses and support them according to their potential deficits is currently in development.

Reducing the rate of fistula: does a fibrin sealant act as an adjunct in pharyngeal closure? A two-centre experience

BACKGROUND

Pharyngocutaneous fistula is a troublesome complication. Recently, synthetic materials such as fibrin sealant have been used as a secondary measure to treat fistula. This work assessed whether the primary use of fibrin sealant can reduce the rate of fistula.

METHOD

A retrospective review of 50 cases from 2 centres was completed. Tisseel was an adjunct to primary closure in all cases.

RESULTS

In the first centre, 3 out of 34 cases developed pharyngocutaneous fistula (fistula rate of 9 per cent). All three were salvage cases. In the second centre, 0 out of 16 cases developed a fistula.

CONCLUSION

The incidence of pharyngocutaneous fistula post-radiation and post-chemoradiotherapy in laryngectomy cases has been quoted as 23 per cent and 34 per cent respectively. This study represents the first patient series on the use of fibrin sealant as an adjunct in primary closure following laryngectomy. The results are promising, encouraging the use of Tisseel as an adjunct to meticulous closure.

Filling of Polyglycolic Acid Sheets for Closure of Gastrointestinal Fistulas With an Easily Deliverable Technique Using a Guidewire

Background

This retrospective study aimed to investigate the suitable indications, methodology and long-term effect of the closure of gastrointestinal (GI) fistulas using polyglycolic acid (PGA) sheets and fibrin glue (FG) and to evaluate the usefulness of a delivery technique using a guidewire.

Methods

It involved 10 applications in six patients (median age 73 (range 53 - 78) years old, three men) with GI fistulas. A guidewire was introduced endoscopically or percutaneously into the fistula beyond the opposite orifice of the fistula with radiologic control. A tapered catheter was inserted over the guidewire, and the fistula was cleaned with an adequate quantity of saline. Subsequently, a small piece of PGA sheet was skewered onto the guidewire at the center and then pushed using the tapered catheter over the guidewire and delivered into the fistula. In cases of endoscopic procedure, the mucosa around the fistula was ablated, and the orifice of the fistula along with the surrounding mucosa was shielded with a piece of PGA sheet fixed with hemoclips and FG.

Results

Technical success of fistula closure was achieved in all applications, and no complications were observed after the procedure. The long-term occlusion of the fistula was ultimately achieved in four of six patients at 202 - 654 days (median duration, 244 days) after the last procedure with one or two applications.

Conclusions

The closure of GI fistulas using PGA sheets and FG demonstrated long-term efficacy for upper GI fistula of a certain length, and the filling technique using a guidewire ensured a safe smooth procedure.

Fibrin sealant for esophageal anastomosis: A phase II study

BACKGROUND

Esophagectomy is a pivotal curative modality for localized esophageal or esophagogastric junction cancer (EC or EJC). Postoperative anastomotic leakage (AL) remains problematic. The use of fibrin sealant (FS) may improve the strength of esophageal anastomosis and reduce the incidence of AL.

AIM

To assess the efficacy and safety of applying FS to prevent AL in patients with EC or EJC.

METHODS

In this single-arm, phase II trial (Clinicaltrial.gov identifier: NCT03529266), we recruited patients aged 18-80 years with resectable EC or EJC clinically staged as T1-4aN0-3M0. An open or minimally invasive McKeown esophagectomy was performed with a circular stapled anastomosis. After performing the anastomosis, 2.5 mL of porcine FS was applied circumferentially. The primary endpoint was the proportion of patients with AL within 3 mo.

RESULTS

From June 4, 2018, to December 29, 2018, 57 patients were enrolled. At the data cutoff date (June 30, 2019), three (5.3%) of the 57 patients had developed AL, including two (3.5%) with esophagogastric AL and one (1.8%) with gastric fistula. The incidence of anastomotic stricture and other major postoperative complications was 1.8% and 17.5%, respectively. The median time needed to resume oral feeding after operation was 8 d (Interquartile range: 7.0-9.0 d). No adverse events related to FS were recorded. No deaths occurred within 90 d after surgery.

CONCLUSION

Perioperative sealing with porcine FS appears safe and may prevent AL after esophagectomy in patients with resectable EC or EJC. Further phase III studies are warranted.

Recent Advances in Tissue Adhesives for Clinical Medicine

Tissue adhesives have attracted more attention to the applications of non-invasive wound closure. The purpose of this review article is to summarize the recent progress of developing tissue adhesives, which may inspire researchers to develop more outstanding tissue adhesives. It begins with a brief introduction to the emerging potential use of tissue adhesives in the clinic. Next, several critical mechanisms for adhesion are discussed, including van der Waals forces, capillary forces, hydrogen bonding, static electric forces, and chemical bonds. This article further details the measurement methods of adhesion and highlights the different types of adhesive, including natural or biological, synthetic and semisynthetic, and biomimetic adhesives. Finally, this review article concludes with remarks on the challenges and future directions for design, fabrication, and application of tissue adhesives in the clinic. This review article has promising potential to provide novel creative design principles for the generation of future tissue adhesives.

The effect of fibrin glue in preventing staple-line leak after sleeve gastrectomy. An experimental study in rats

Purpose

To evaluate the effect of fibrin glue on staple-line leak after sleeve gastrectomy.

Methods

Fourteen adult wistar rats 300 gr were randomized into two groups: Control group (n=7) and study group (n=7). All the rats underwent sleeve gastrectomy using lineer stapler. In the study group, fibrin glue was used to reinforce the staple-line. The rats were sacrificed 7 days after surgery. The stomach was resected, submerged in saline and exposed to excess pressure to obtain a burst pressure value. The gastric staple line was evaluated histopathologically according to the Ehrlich Hunt scale. The results of the two groups were compared.

Results

The mean Ehrlich-Hunt scores for inflammation, fibroblastic activity and neo-angiogenesis were similar between the groups (p>0.05). Collagen deposition was significantly higher in study group (3.42±0.53) when compared with control group (2.57±0.78) (p=0.035). The mean burst pressure was 137.8±8.5 mmHg for control group and 135.0±8.1 mmHg for study group (p=0.536).

Conclusion

Reinforcement of the staple-line with fibrin glue has no effect on the burst pressure after sleeve gastrectomy. More studies are needed to evaluate the precautions against leak after sleeve gastrectomy.

Frequency and severity of hypersensitivity reactions in patients after VenaSeal™ cyanoacrylate treatment of superficial venous insufficiency

Objective

Hypersensitivity reaction presenting as a distinctive erythematous rash has been reported following VenaSeal™ cyanoacrylate adhesive closure. We report the frequency of hypersensitivity reactions, time to onset, duration, and severity of symptoms in patients treated with cyanoacrylate adhesive closure at a single institution. Patient and procedural factors associated with hypersensitivity reactions were evaluated.

Methods

A combined retrospective/prospective review of cyanoacrylate adhesive closure-treated patients was conducted over five years. Data collected from electronic medical records were reviewed for the presence of hypersensitivity reactions along with the time of onset, duration of symptoms, and severity of reaction. Severity was classified as mild if no treatment or over the counter medication was provided, moderate if steroids were required, and severe if the reaction lasted >30 days or required vein excision.

Results

Three hundred and seventy-nine limbs were treated in 286 patients (313 treatment days). Hypersensitivity reactions occurred in 18 patients (5.8% treatments, 6.3% patients). Thirteen were mild (4.2%), four were moderate (1.3%), and one was severe (0.3%). No patient or procedural predictive factors for hypersensitivity reaction were identified other than a trend towards decreased hypersensitivity reactions in patients with Clinical, Etiologic, Anatomic, Pathophysiologic (CEAP) clinical class C4–C6 (p = .06). Second limb treatment on a subsequent day was performed in 27 patients, and no hypersensitivity reactions occurred. Symptom onset time ranged from 1 to 23 days, with a mean of 13 days (confidence interval (CI) ±3.5 days). Duration of symptoms ranged from 3 to 28 days (mean 10.8 CI ±4.9 days).

Conclusions

Hypersensitivity reactions occurred in 6.0% of patients treated with cyanoacrylate adhesive closure, but most were mild and self-limited. Severe reactions were uncommon. No predictive patient or procedural factors were found to be associated with hypersensitivity reactions other than a trend towards decreased risk in patients with advanced CEAP clinical class. Previous cyanoacrylate adhesive closure treatment was not a predictive factor for hypersensitivity reaction in patients undergoing treatment at a later date.

Preventive strategies for anastomotic leakage after colorectal resections: A review

Anastomosis is a crucial step in radical cancer surgery. Despite being a daily practice in gastrointestinal surgery, anastomotic leakage (AL) stands as a frequent postoperative complication. Because of increased morbidity, mortality, combined with longer hospital stay, the rate of re-intervention, and poor oncological outcomes, AL is considered the most feared and life-threatening complication after colorectal resections. Furthermore, poor functional outcomes with a higher rate of a permeant stoma in 56% of patients this could negatively affect the patient’s quality of life. This a narrative review which will cover intraoperative anastomotic integrity assessment and preventive measures in order to reduce AL. Although the most important prerequisites for the creation of anastomosis is well-perfused and tension-free anastomosis, surgeons have proposed several preventive measures, which were assumed to reduce the incidence of AL, including antibiotic prophylaxis, intraoperative air leak test, omental pedicle flap, defunctioning stoma, pelvic drain insertion, stapled anastomosis, and general surgical technique. However, lack of clear evidence of which preventive measures is superior over the other combined with the fact that the decision remains based on the surgeon’s choice. Despite the advances in surgical techniques, AL remains a serious health problem associated with increased morbidity, mortality with additional cost. Many preventative measures were employed with no clear evidence supporting the superiority of stapled anastomosis over hand-Sewn anastomosis, coating of the anastomosis, or pelvic drain. Defunctioning stoma, when justified it could decrease the leakage-related complications and the incidence of reoperation. MBP combined with oral antibiotics still recommended.

Reinforcement of intrathoracic oesophago-gastric anastomosis with fibrin sealant (Tisseel®) in oesophagectomy for cancer: A prospective comparative study

PURPOSE

Fibrin sealant (Tisseel) is a human protein and thrombin soluble fibrinogen that has been indicated for reinforcement of gastro-intestinal anastomoses to prevent leakage. The objective of this study is to examine the impact of fibrin sealant regarding anastomotic leak, following Ivor-Lewis procedure.

METHODS

This is a prospective comparative study on 2-stage oesophagectomy for cancer of the distal oesophagus or oesophagogastric junction. N = 57 individuals were randomly subjected; n = 22 patients to Tisseel in combination to surgical anastomosis versus n = 35 patients to surgical anastomosis alone. The test of probability was assessed through Chi-Square, independent samples paired T-Test and Log-Rank analysis.

RESULTS

Of the 57 cases included, 56 underwent hybrid and 1 open oesophagectomy. In the Tisseel group, n = 5(22.7%) developed anastomotic leak comparing to n = 3(8.6%) of the control group. No statistically significant difference in leak rate was shown between the two groups; the test of probability was rejected.

CONCLUSIONS

Our results are not supportive of Tisseel tissue sealing property on the intrathoracic oesophago-gastric anastomosis and fibrin sealant's use cannot be justified.

Adipose-Derived Mesenchymal Stromal Cells Improve the Healing of Colonic Anastomoses Following High Dose of Irradiation Through Anti-Inflammatory and Angiogenic Processes

Cancer patients treated with radiotherapy (RT) could develop severe late side effects that affect their quality of life. Long-term bowel complications after RT are mainly characterized by a transmural fibrosis that could lead to intestinal obstruction. Today, surgical resection is the only effective treatment. However, preoperative RT increases the risk of anastomotic leakage. In this study, we attempted to use mesenchymal stromal cells from adipose tissue (Ad-MSCs) to improve colonic anastomosis after high-dose irradiation. MSCs were isolated from the subcutaneous fat of rats, amplified in vitro, and characterized by flow cytometry. An animal model of late radiation side effects was induced by local irradiation of the colon. Colonic anastomosis was performed 4 wk after irradiation. It was analyzed another 4 wk later (i.e., 8 wk after irradiation). The Ad-MSC-treated group received injections several times before and after the surgical procedure. The therapeutic benefit of the Ad-MSC treatment was determined by colonoscopy and histology. The inflammatory process was investigated using Fluorine-182-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography and Computed Tomography (¹⁸F-FDG-PET/CT) imaging and macrophage infiltrate analyses. Vascular density was assessed using immunohistochemistry. Results show that Ad-MSC treatment reduces ulcer size, increases mucosal vascular density, and limits hemorrhage. We also determined that 1 Ad-MSC injection limits the inflammatory process, as evaluated through ¹⁸F-FDG-PET-CT (at 4 wk), with a greater proportion of type 2 macrophages after iterative cell injections (8 wk). In conclusion, Ad-MSC injections promote anastomotic healing in an irradiated colon through enhanced vessel formation and reduced inflammation. This study also determined parameters that could be improved in further investigations.

A web-based overview, systematic review and meta-analysis of pancreatic anastomosis techniques following pancreatoduodenectomy

BACKGROUND

Many pancreatic anastomoses have been proposed to reduce the incidence of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy, but a complete overview is lacking. This systematic review and meta-analysis aims to provide an online overview of all pancreatic anastomosis techniques and to evaluate the incidence of clinically relevant POPF in randomized controlled trials (RCTs).

METHODS

A literature search was performed to December 2017. Included were studies giving a detailed description of the pancreatic anastomosis after open pancreatoduodenectomy and RCTs comparing techniques for the incidence of POPF (International Study Group of Pancreatic Surgery [ISGPS] Grade B/C). Meta-analyses were performed using a random-effects model.

RESULTS

A total of 61 different anastomoses were found and summarized in 19 subgroups (www.pancreatic-anastomosis.com). In 6 RCTs, the POPF rate was 12% after pancreaticogastrostomy (n = 69/555) versus 20% after pancreaticojejunostomy (n = 106/531) (RR0.59; 95%CI 0.35-1.01, P = 0.05). Six RCTs comparing subtypes of pancreaticojejunostomy showed a pooled POPF rate of 10% (n = 109/1057). Duct-to-mucosa and invagination pancreaticojejunostomy showed similar results, respectively 14% (n = 39/278) versus 10% (n = 27/278) (RR1.40, 95%CI 0.47-4.15, P = 0.54).

CONCLUSION

The proposed online overview can be used as an interactive platform, for uniformity in reporting anastomotic techniques and for educational purposes. The meta-analysis showed no significant difference in POPF rate between pancreatic anastomosis techniques.

A systematic review on the use of topical hemostats in trauma and emergency surgery

BACKGROUND

A wide variety of hemostats are available as adjunctive measures to improve hemostasis during surgical procedures if residual bleeding persists despite correct application of conventional methods for hemorrhage control. Some are considered active agents, since they contain fibrinogen and thrombin and actively participate at the end of the coagulation cascade to form a fibrin clot, whereas others to be effective require an intact coagulation system. The aim of this study is to provide an evidence-based approach to correctly select the available agents to help physicians to use the most appropriate hemostat according to the clinical setting, surgical problem and patient's coagulation status.

METHODS

The literature from 2000 to 2016 was systematically screened according to PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] protocol. Sixty-six articles were reviewed by a panel of experts to assign grade of recommendation (GoR) and level of evidence (LoE) using the GRADE [Grading of Recommendations Assessment, Development and Evaluation] system, and a national meeting was held.

RESULTS

Fibrin adhesives, in liquid form (fibrin glues) or with stiff collagen fleece (fibrin patch) are effective in the presence of spontaneous or drug-induced coagulation disorders. Mechanical hemostats should be preferred in patients who have an intact coagulation system. Sealants are effective, irrespective of patient's coagulation status, to improve control of residual oozing. Hemostatic dressings represent a valuable option in case of external hemorrhage at junctional sites or when tourniquets are impractical or ineffective.

CONCLUSIONS

Local hemostatic agents are dissimilar products with different indications. A knowledge of the properties of each single agent should be in the armamentarium of acute care surgeons in order to select the appropriate product in different clinical conditions.

Influence of Early Postoperative Feeding in Gastrointestinal Anastomotic Fistula Formation and Healing Time in Rabbits

OBJECTIVES

To determine whether early postoperative feeding attenuates the inhibitory effects of intestinal anastomosis in rabbits.

METHODS

After undergoing gastrointestinal anastomosis, 48 rabbits were randomly divided into experimental and control groups. The rabbits in the experimental group were fed a liquid diet beginning 24 h postoperatively, while the control rabbits received only total parenteral nutrition after the operation. Exploratory laparotomies were performed on four rabbits in each group 3, 5, 7, 10, and 15 days postoperatively, and the healing rate of the anastomosis, anastomotic bursting pressure, anastomotic breaking strength, and hydroxyproline content at the anastomosis were determined.

RESULTS

The anastomoses healed in 91.6% (22/24) of the control group and 95.8% (23/24) of the experimental group. The anastomotic bursting pressure decreased remarkably in both groups 3 days postoperatively, reaching the lowest value. The anastomotic breaking strength did not differ between the two groups 3 days postoperatively, when both reached their lowest points, and both groups increased markedly and peaked 10 days postoperatively. The hydroxyproline content of the anastomosis was slightly lower in the experimental group 3 days postoperatively, although both groups peaked 7 days postoperatively.

CONCLUSIONS

Early postoperative feeding does not increase the anastomosis healing time or rate of gastrointestinal anastomosis leakage.

Endoscopic Treatment of Diverse Complications Caused by Laparoscopic Adjustable Gastric Banding: A Study in Eastern Asia

Background/Aims

The use of laparoscopic adjustable gastric banding (LAGB) is increasing proportionally with the obesity epidemic. However, some postoperative complications have been highlighted as major problems associated with LAGB. There is no consensus concerning the endoscopic management of these adverse events. The aim of this study was to retrospectively review the feasibility and effectiveness of endoscopic treatment for LAGB complications.

Methods

We retrospectively evaluated 352 patients who underwent LAGB between 2011 and 2015. LAGB-associated complications developed in 26 patients (7.4%). This study involved six patients (1.7%) who received endoscopic treatment.

Results

Types of LAGB-induced complications in our series included intragastric migration (n=3), gastric leaks (n=2), and gastric fistulas (n=1). The endoscopic treatment of these complications was successful in four of the six patients. Endoscopic band removal was successful in two patients. All gastric leaks were successfully closed via an endoscopic procedure. In two cases (intragastric migration and gastric fistula), endoscopic treatment was not sufficient, and surgery was performed.

Conclusions

Endoscopic procedures afforded acceptable treatment of band migration and gastric leaks after LAGB. However, the results were poor in patients with gastric fistula.

Sealing with Cyanoacrylate and a Falciform Patch Cannot Prevent Postoperative Pancreatic Fistula

BACKGROUND

This study aimed to evaluate the effect of a new combined method of covering the pancreatic anastomosis or stump with a cyanoacrylate and a falciform patch (CAFP) on the occurrence of postoperative pancreatic fistula (POPF).

METHODS

Patients undergoing a pancreaticoduodenectomy (PD) or a distal pancreatectomy (DP) were recruited over a period of 12 months. The pancreaticojejunostomy in PD and the stump in DP were sealed with cyanoacrylate glue and wrapped in a falciform patch. Incidence and severity of POPF and associated postoperative complications were retrospectively compared with historical controls of 750 PD and 336 DP at the same institution and with current data from the literature.

RESULTS

The new method was applied in 27 PD and 25 DP. The rate of clinically relevant POPF after PD with CAFP was 22.2% compared to 14.4% in historical patients, p = 0.26. The rate of clinically relevant POPF after DP with CAFP was 36% compared to 30% in historical patients, p = 0.65.

CONCLUSION

Sealing the pancreatic anastomosis or stump with a combination of a cyanoacrylate glue and a falciform patch didn't reduce the rate of POPF after major pancreatic resections.

Different types of pancreatico-enteric anastomosis

The pancreatico-enteric anastomosis has widely been regarded as the 'Achilles heel' of the modern day, single-stage, pancreatoduodenectomy (PD). A review of the literature was carried out to address the evolution of the pancreatico-enteric anastomosis following PD, the spectrum of anastomoses performed around the world, and finally present the current evidence in support of each anastomosis. Pancreaticogastrostomy (PG) and pancreaticojejunostomy (PJ) are the most common forms of pancreatico-enteric reconstruction following PD. There is no difference in postoperative pancreatic fistula (POPF) rates between PG and PJ, as well as individual variations, except in a high-risk anastomosis where performance of a PJ may be preferred. The routine use of glue, trans-anastomotic stents or omental wrapping is of no proven benefit. Externalised trans-anastomotic stents may have a role in mitigating the risk of a clinically relevant POPF in high-risk anastomoses. Pancreatico-enteric anastomosis is an important component of reconstruction following PD even though it is fraught with the risk of development of a POPF. Adherence to the tenets of anastomotic reconstruction and performance of a safe and reproducible anastomosis with a low clinically-relevant POPF rate remain the mainstay of achieving the best outcomes. Appropriate selection and opportune use of fistula mitigation strategies may help provide optimal outcomes when faced with the need to perform a high-risk pancreatico-enteric anastomosis.

Solution blow spun polymer: A novel preclinical surgical sealant for bowel anastomoses

BACKGROUND

Solution blow spinning is a technique for depositing polymer fibers with promising potential use as a surgical sealant. This study assessed the feasibility and efficacy of solution blow spun polymer (BSP) for sealing bowel perforations in a mouse model of partial cecal transection. We then evaluated its use for reinforcing a surgical anastomosis in a preclinical piglet model.

METHODS

Three commercially available surgical sealants (fibrin glue, polyethylene glycol (PEG) hydrogel, and cyanoacrylate) were compared to BSP in the ability to seal partially transected cecum in mice. For anastomosis feasibility testing in a piglet model, piglets were subjected to small bowel transection with sutured anastomosis reinforced with BSP application. Outcome measures included anastomotic burst pressure, anastomotic leak rate, 14-day survival, and complication rate.

RESULTS

For the mouse model, the survival rates for the sealants were 30% for fibrin glue, 20% for PEG hydrogel, 78% for cyanoacrylate, and 67% for BSP. Three of 9 mice died after BSP administration because of perforation leak, failure to thrive with partial obstruction at the perforation site, and unknown causes. All other mice died of perforation leak. The mean burst pressure at 24h was significantly higher for BSP (81mm Hg) when compared to fibrin glue (6mm Hg, p=0.047) or PEG hydrogel (10mm Hg, p=0.047), and comparable to cyanoacrylate (64mm Hg, p=0.91). For piglets, 4 of 4 animals survived at 14days. Mean burst pressures at time of surgery were 37±5mm Hg for BSP and 11±9mm Hg for suture-only controls (p=0.09).

CONCLUSIONS

Solution blow spinning may be an effective technique as an adjunct for sealing of gastrointestinal anastomosis. Further preclinical testing is warranted to better understand BSP properties and alternative surgical applications.

Sutures versus new cyanoacrylates in prosthetic abdominal wall repair: a preclinical long-term study

BACKGROUND

As an alternative to sutures, meshes used for hernia repair can be fixed using cyanoacrylate-based adhesives. Attempts to improve these adhesives include alkyl-chain lengthening to reduce their toxicity. This preclinical study compares the long-term behavior of cyanoacrylates of different chain lengths already used in hernia repair and new ones for this application.

MATERIALS AND METHODS

Partial abdominal wall defects were repaired using a Surgipro mesh in 18 New Zealand White rabbits, and groups were established according to the mesh fixation method: sutures (control), Glubran 2 (n-butyl), Ifabond (n-hexyl), and the new adhesives SafetySeal (n-butyl), and Evobond (n-octyl). Six months after surgery, recovered implants were examined to assess adhesive degradation, host tissue reaction, and biomechanical strength.

RESULTS

All the cyanoacrylate groups showed good host tissue incorporation in the meshes. Macrophage responses to Glubran and Ifabond were quantitatively greater compared with sutures. Cell damage caused by the adhesives was similar, and only Glubran induced significantly more damage than sutures. Significantly lower collagen 1/3 messenger RNA expression was induced by Ifabond than the remaining fixation materials. No differences were observed in collagen expression except slightly reduced collagen I deposition in Glubran/Ifabond and collagen III deposition in the suture group. Mechanical strengths failed to vary between the suture and cyanoacrylate groups.

CONCLUSIONS

All cyanoacrylates showed good long-term behavior and tolerance irrespective of their long or intermediate chain length. Cyanoacrylate residues persisted at 6 mo, indicating their incomplete degradation. Biomechanical strengths were similar both for the adhesives and sutures.

Technical Details of Laparoscopic Sleeve Gastrectomy Leading to Lowered Leak Rate: Discussion of 1070 Consecutive Cases

Introduction

Laparoscopic sleeve gastrectomy is a widely utilized and effective surgical procedure for dramatic weight loss in obese patients. Leak at the sleeve staple line is the most serious complication of this procedure, occurring in 1–3% of cases. Techniques to minimize the risk of sleeve gastrectomy leaks have been published although no universally agreed upon set of techniques exists. This report describes a single-surgeon experience with an approach to sleeve leak prevention resulting in a progressive decrease in leak rate over 5 years.

Methods

1070 consecutive sleeve gastrectomy cases between 2012 and 2016 were reviewed retrospectively. Patient characteristics, sleeve leaks, and percent body weight loss at 6 months were reported for each year. Conceptual and technical changes aimed towards leak reduction are presented.

Results

With the implementation of the described techniques of the sleeve gastrectomy, the rate of sleeve leaks fell from 4% in 2012 to 0% in 2015 and 2016 without a significant change in weight loss, as depicted by 6-month change in body weight and percent excess BMI lost.

Conclusion

In this single-surgeon experience, sleeve gastrectomy leak rate has fallen to 0% since the implementation of specific technical modifications in the procedure.

The Physiological Incubation Biosimulator (PIBS): An Improved Ex Vivo Experimental Setup for the Mechanical Stability of Biological Sealants in Surgical Procedures

BACKGROUND

Tissue-bound fibrin sealants are used in a wide array of surgical procedures. The microenvironmental interaction between sealant and application site is often poorly evaluated due to a lack of suitable experimental models.

METHODS

A physiological incubation biosimulator (PIBS) was developed to test biological sealants in an ex vivo setup under physiological conditions comparable to the microenvironment at application site (temperature, humidity, pressure). PIBS was validated by a study on the effectiveness of TachoSil for leak closure at pancreatic resection sites. Defined defects in a thoracic membrane of porcine origin were sealed by TachoSil. Integrity of the sealing was tested in the presence of active pancreatic fluid over 60 minutes. Heat-inactivated pancreatic fluid and electrolyte solution served as controls. The time to leakage was recorded and experimental groups were analyzed by Kaplan-Meier analysis.

RESULTS

PIBS produced reliable results. TachoSil lead to a leakage rate of 96% after incubation with active pancreatic fluid (p = 34), which was significantly higher compared with heat-inactivated pancreatic fluid (p = 34, 52%) or electrolyte solution (p = 20, 19%).

CONCLUSION

PIBS is an effective tool to evaluate microenvironmental effects on the adhesive strength of biomaterials. Tissue sealing effect of TachoSil is diminished in a "pancreatic" microenvironment rich with pancreatic enzymes. Our results might therefore explain the reason of the findings of randomized controlled trials recently published on this subject.

Anastomotic leaks in gastrointestinal surgery and their prevention

Anastomotic leak in the gastrointestinal tract is one of the most important complications of resection. They are the main cause of reoperation, their occurrence worsens the prognosis of the patient, increasing the proportion of direct mortality, as well as being a significant risk factor for recurrence of cancer. The risk of leaks within the gastrointestinal tract is greatly varied, depending on the location and extent of the resection, but also on patient, disease or a surgical procedure, including surgeon. To determine the potential risk of leakage can be significant for introduction some prophylactic actions. Some of them have the character of general recommendations, as proper nutrition of the patient in the perioperative period, while another part is directly connected to the surgical procedure. The second group includes protective stoma, the use of tissue glues, insertion transrectal drain for rectal anastomosis decompression, the use of stents or the use of collagen matrix coated with fibrinogen and thrombin. Important to reduce the proportion of leaks can be more precise and targeted prophylactic recommendations, based on the individualized determination of risk factors leaks. Further research for this purpose are necessary for this purpose, the big hope can be associated with data obtained through mobile applications.