Cyanoacrylate applications in the GI tract

Endoscopic ultrasound-guided vascular interventions: An expanding paradigm

Endoscopic ultrasound (EUS) has expanded its arena from a mere diagnostic modality to an essential therapeutic tool in managing gastrointestinal (GI) diseases. The proximity of the GI tract to the vascular structures in the mediastinum and the abdomen has facilitated the growth of EUS in the field of vascular interventions. EUS provides important clinical and anatomical information related to the vessels' size, appearance and location. Its excellent spatial resolution, use of colour doppler with or without contrast enhancement and ability to provide images “real-time” helps in precision while intervening vascular structures. Additionally, structures such as venous collaterals or varices can be dealt with optimally using EUS. EUS-guided vascular therapy with coil and glue combination has revolutionized the management of portal hypertension. It also helps to avoid radiation exposure in addition to being minimally invasive. These advantages have led EUS to become an upcoming modality to complement traditional interventional radiology in the field of vascular interventions. EUS-guided portal vein (PV) access and therapy is a new kid on the block. EUS-guided portal pressure gradient measurement, injecting chemotherapy in PV and intrahepatic portosystemic shunt has expanded the horizons of endo-hepatology. Lastly, EUS has also forayed into cardiac interventions allowing pericardial fluid aspiration and tumour biopsy with experimental data on access to valvular apparatus. Herein, we provide a comprehensive review of the expanding paradigm of EUS-guided vascular interventions in GI bleeding, portal vein access and its related therapeutic interventions, cardiac access, and therapy. A synopsis of all the technical details involving each procedure and the available data has been tabulated, and the future trends in this area have been highlighted.

A Narrative Review of Different Hemostatic Materials in Emergency Treatment of Trauma

Hemostatic materials are very important for the treatment of a large number of bleeding trauma patients in battlefield and disaster environments. Different types of hemostatic materials need to be used for emergency hemostasis according to different injury parts and severity. At present, the first-aid hemostatic materials have been well applied to the bleeding of body surface wounds, limbs, and junctions, but there are still no ideal hemostatic materials in the early treatment of first aid for the deep and incompressible bleeding of thoracoabdominal cavity and visceral organs. This paper reviews the classification and mechanism of hemostatic materials, as well as the application and research progress in trauma emergency, so as to provide reference for the application of hemostatic materials in early first-aid emergency.

Endoscopic ultrasound-guided cyanoacrylate injection to prevent rebleeding in hepatocellular carcinoma patients with variceal hemorrhage

BACKGROUND AND AIM

Secondary prophylaxis (SP) of variceal rebleeding was reported to improve outcomes of hepatocellular carcinoma (HCC) patients, but the optimal endoscopic approach is not well defined. We compared outcomes in HCC patients who underwent SP by endoscopic ultrasound-guided cyanoacrylate obturation (EUS-CYA) versus no SP.

METHODS

Between 2014 and 2018, 30 consecutive patients with inoperable HCC and recent endoscopically controlled variceal bleeding were prospectively recruited. Twenty-seven patients with persistent varices ≥ 3 mm on endoscopic ultrasound underwent EUS-CYA for SP. Thirty-three HCC patients treated by esophagogastroduodenoscopy-guided CYA obturation (EGD-CYA) alone for acute variceal bleeding between 2009 and 2013 were identified from a prospective gastrointestinal bleed registry as standard of care controls for comparison. Outcome measures were death-adjusted cumulative incidence of rebleeding, bleeding-free survival, technical success, and procedure-related adverse events of EUS-CYA.

RESULTS

The majority of patients in both groups had advanced HCC, portal vein thrombosis, and Child-Pugh B cirrhosis. EUS-CYA was successful in all 27 patients with no radiographic evidence of cyanoacrylate-lipiodol embolization. Significantly lower 30- and 90-day death-adjusted cumulative incidence of rebleeding (14.8% vs 42.4%, P = 0.023 and 18.5% vs 60.6%, P = 0.002, respectively) and significantly higher variceal bleeding-free survival at 3 and 6 months (51.9% vs 21.2%, P = 0.009, 40.7% vs 15.2%, P = 0.010, respectively) were observed in the EUS-CYA group when compared with standard of care group.

CONCLUSIONS

Secondary prophylaxis by EUS-CYA reduced rebleeding rate and improved variceal bleeding-free survival in patients with inoperable HCC and variceal bleeding when compared with no SP. Randomized studies are needed to confirm the benefits of EUS-CYA for this difficult-to-treat population.

The recent progress of tissue adhesives in design strategies, adhesive mechanism and applications

Tissue adhesives have emerged as an effective method for wound closure and hemostasis in recent decades, due to their ability to bond tissues together, preventing separation from one tissue to another. However, existing tissue adhesives still have several limitations. Tremendous efforts have been invested into developing new tissue adhesives by improving upon existing adhesives through different strategies. Therefore, highlighting and analyzing these design strategies are essential for developing the next generation of advanced adhesives. To this end, we reviewed the available strategies for modifying traditional adhesives (including cyanoacrylate glues, fibrin sealants and BioGlue), as well as design of emerging adhesives (including gelatin sealants, methacrylated sealants and bioinspired adhesives), focusing on their structures, adhesive mechanisms, advantages, limitations, and current applications. The bioinspired adhesives have numerous advantages over traditional adhesives, which will be a wise direction for achieving tissue adhesives with superior properties.

SAFETY AND EFFICACY OF EUS-GUIDED COIL PLUS CYANOACRYLATE VERSUS CONVENTIONAL CYANOACRYLATE TECHNIQUE IN THE TREATMENT OF GASTRIC VARICES: A RANDOMIZED CONTROLLED TRIAL

BACKGROUND

One of the most feared complications with the use of cyanoacrylate for treatment of gastric varices is the occurrence of potentially life-threatening systemic embolism. Thus, endoscopists are turning towards new techniques, including endoscopic coiling, as a potentially safer and more effective treatment option. However, no studies have been performed comparing the two techniques.

OBJECTIVE

This study aims to compare the safety and efficacy of endoscopic ultrasound guided coil and cyanoacrylate injection versus the conventional technique of injection of cyanoacrylate alone.

DESIGN

A pilot randomized controlled trial.

METHODS

Patients randomized into group I were treated with coil and cyanoacrylate, and those in group II with cyanoacrylate alone. Flow within the varix was evaluated immediately after the treatment session and one month following initial treatment. If thrombosis was confirmed, additional follow-up was performed 4 and 10 months following initial treatment. All patients underwent a thoracic computerized tomography scan after the procedure.

RESULTS

A total of 32 patients, 16 in each group, were followed for an average of 9.9 months (range 1-26 months). Immediately after the procedure, 6 (37.5%) group-I patients and 8 (50%) group-II patients presented total flow reduction in the treated vessel (P=0.476). After 30 days, 11 (73.3%) group-I patients and 12 (75%) group-II patients were found to have varix thrombosis. In both groups, the majority of patients required only one single session for varix obliteration (73.3% in group I versus 80% in group II). Asymptomatic pulmonary embolism occurred in 4 (25%) group-I patients and 8 (50%) group-II patients (P=0.144). No significant difference between the groups was observed.

CONCLUSION

There is no statistical difference between endoscopic ultrasound guided coils plus cyanoacrylate versus conventional cyanoacrylate technique in relation to the incidence of embolism. However, a greater tendency towards embolism was observed in the group treated using the conventional technique. Both techniques have similar efficacy in the obliteration of varices. Given the small sample size of our pilot data, our results are insufficient to prove the clinical benefit of the combined technique, and do not yet justify its use, especially in light of higher cost. Further studies with larger sample size are warranted.

Endoscopic treatment of esophageal fistulas after esophagectomy with injection of an alpha-cyanoacrylate monomer: a phase II study

Background and study aims  Interventional endoscopic treatments including the application of glue are becoming more frequently used for the treatment of esophageal fistulas. However, there are no prospective studies of endoscopic treatment for esophageal fistulas. This prospective study aims to investigate the efficacy and safety of endoscopic injection of alpha-cyanoacrylate monomer for intractable esophageal fistulas. Patients and methods  This single-center prospective phase II trial included patients with more than 1 wk of conservative medical treatment for intractable esophageal fistulas after esophagectomy. In the image-guided therapy suite, a mixture of alpha-cyanoacrylate monomer and oily contrast agent in a ratio of 0.3 to 1.7 mL was endoscopically injected through the fistula. Results  Twenty-five patients who underwent esophagectomy at Wakayama Medical University Hospital were enrolled in this study. The primary disease was esophageal cancer in 16 patients (64 %) and gastric cancer in the remaining 9 patients (36 %). Complete closure of the esophageal fistula was performed in 22 patients after endoscopic injection of alpha-cyanoacrylate monomer. The overall success rate was 88 %. There was no fistula recurrence in any successful closure cases. Three patients with failed esophageal fistula closure had esophageal cancer with cervical esophageal fistulas and required reoperation of the fistulectomy under general anesthesia. No complications associated with this endoscopic treatment were detected. Conclusions  Endoscopic treatment with injection of alpha-cyanoacrylate monomer facilitated healing of post-esophagectomy fistula in 88 % of patients without complications. This suggests that the treatment is effective and safe for patients with esophageal fistulas.

Saphenous vein ablation with a new cyanoacrylate glue device: a systematic review on 1000 cases

BACKGROUND

To review published evidence regarding an n-butyl-cyanoacrylate (NBCA) injection device for great (GSV) and small (SSV) saphenous vein incompetence in terms of occlusion rate, postoperative complications and quality of life improvement.

MATERIAL AND METHODS

International bibliographic databases (PubMed, EMBASE, Scopus) were searched to identify possible target articles. The only inclusion criterion was the use of the Variclose^® system (Biolas, Ankara, Turkey) for superficial vein insufficiency. Exclusion criteria were case reports, review, meta-analysis, article with <6-month follow-up data, abstracts and congress presentations. PRISMA guidelines were used to lead articles selection.

RESULTS

Seven studies were included in the final data analysis. A total of 918 patients (1000 limbs) underwent an NBCA procedure for GSV (947 cases) or SSV (53 cases) incompetence. The average procedure duration was 11.7 min. The most common postoperative complications were postoperative pain (4.8%) and superficial vein thrombosis (2.1%). No deep vein thrombosis or pulmonary embolism cases were described. The occlusion rates at six, 12 and 30 months were 97.3%, 96.8% and 94.1%, respectively.

CONCLUSION

NBCA injection with the Variclose device seems to be a feasible, effective and safe treatment in GSV incompetence. Long-term follow-up studies and randomized controlled trials are needed to achieve high-quality evidence.

Covalently-controlled drug delivery via therapeutic methacrylic tissue adhesives

Therapeutic methacrylic (TMA) monomers lend local, covalently-controlled release of therapeutics, tunable mechanical properties, and increased cytocompatibility to cyanoacrylate medical adhesives.

Non-variceal upper gastrointestinal bleeding: Rescue treatment with a modified cyanoacrylate

AIM

To evaluate the safety and efficacy of a modified cyanoacrylate [N-butyl-2-cyanoacrylate associated with methacryloxysulfolane (NBCA + MS)] to treat non-variceal upper gastrointestinal bleeding (NV-UGIB).

METHODS

In our retrospective study we took into account 579 out of 1177 patients receiving endoscopic treatment for NV-UGIB admitted to our institution from 2008 to 2015; the remaining 598 patients were treated with other treatments. Initial hemostasis was not achieved in 45 of 579 patients; early rebleeding occurred in 12 of 579 patients. Thirty-three patients were treated with modified cyanoacrylate: 27 patients had duodenal, gastric or anastomotic ulcers, 3 had post-mucosectomy bleeding, 2 had Dieulafoy’s lesions, and 1 had duodenal diverticular bleeding.

RESULTS

Of the 45 patients treated endoscopically without initial hemostasis or with early rebleeding, 33 (76.7%) were treated with modified cyanoacrylate glue, 16 (37.2%) underwent surgery, and 3 (7.0%) were treated with selective transarterial embolization. The mean age of patients treated with NBCA + MS (23 males and 10 females) was 74.5 years. Modified cyanoacrylate was used in 24 patients during the first endoscopy and in 9 patients experiencing rebleeding. Overall, hemostasis was achieved in 26 of 33 patients (78.8%): 19 out of 24 (79.2%) during the first endoscopy and in 7 out of 9 (77.8%) among early rebleeders. Two patients (22.2%) not responding to cyanoacrylate treatment were treated with surgery or transarterial embolization. One patient had early rebleeding after treatment with cyanoacrylate. No late rebleeding during the follow-up or complications related to the glue injection were recorded.

CONCLUSION

Modified cyanoacrylate solved definitively NV-UGIB after failure of conventional treatment. Some reported life-threatening adverse events with other formulations, advise to use it as last option.

Intraoperative salvage endoscopy performed during orthotopic liver transplantation due to esophageal bleeding

Introduction

Liver transplantation (LTx) is a widely accepted method of treatment for end stage liver diseases. There are many reports on the management of gastrointestinal bleeding (GIB) after LTx, however the number of studies concerning salvage endoscopic procedures during LTx are scarce.

Aim

We present our material of intraoperative endoscopic procedures due to GIB during LTx.

Material and methods

During this period there were 4 females and 1 male at the mean age of 52.2 (35–65) years who underwent LTx and 1 patient had Re-LTx. All patients were Child-Pugh group C and mean MELD score was 17.75. Esophageal and/or gastric varices were present before surgery in all patients but only 1 female patient didn't experience GIB prior to LTx. Variables such as operating time, cold ischemic time, blood loss, blood transfusion, PLT count, international normalized ratio, albumin levels were similar in all patients thus making it statistically insignificant as the cause of GIB.

Results

In all cases a single IOE was necessary and bleeding from ruptured varices succumbed to endoscopic ligation. In 2 patients besides trials of ligating the varix, histoacryl was put in use which proved success. In both these last female patients the endoscopic physician had to insert a Danis stent. A follow up endoscopy was performed on the 7–10 POD.

Conclusions

Intra-operative endoscopy performed during LTx does not interrupt surgery. Performed as soon as possible results in less future endoscopic interventions due to GIB. Intraoperative endoscopy may be considered as a salvage procedure and should be performed in the shortest possible time.

Endoscopic management of refractory gastrointestinal non-variceal bleeding using Histoacryl (N-butyl-2-cyanoacrylate) glue

Background: Histoacryl glue (N-butyl-2-cyanoacrylate) has well-established utility in the endoscopic management of gastrointestinal variceal bleeding. The role of Histoacryl glue in non-variceal bleeding is less clear, and there are few articles describing its use in this setting.

Methods: Six patients with intractable non-variceal gastrointestinal bleeding were managed using injection of Histoacryl glue. All patients had previously failed conventional endostasis and/or interventional angioembolization and were not suitable for emergency salvage surgery due to serious comorbidities or unacceptable anaesthetic risk. An endoscopic Lipiodol-Histoacryl-Lipiodol sandwich injection technique was used in these patients. The clinical outcomes and complications were evaluated.

Results: There were four females and two males with a mean age of 55 years. Bleeding lesions included gastric ulcers (n = 2), duodenal ulcers (n = 2), duodenal gastrointestinal stromal tumor (GIST) (n = 1) and rectal ulcers (n = 1). All patients had successful Histoacryl endostasis without the requirement for salvage surgery. There was no treatment-related morbidity and no mortality. Two patients had further bleeding after initial Histoacryl endostasis, which was successfully controlled with further endoscopic Histoacryl injection.

Conclusion: Histoacryl endostasis should be included in the treatment algorithm for refractory non-variceal gastrointestinal bleeding.

Potential application of interventional endoscopic ultrasonography for the treatment of esophageal and gastric varices

Interventional endoscopic ultrasonography (EUS) has been developed mainly for the treatment of pancreaticobiliary disorders (e.g. cyst drainage for pancreatic pseudocysts, biliary drainage for malignant biliary obstruction, and celiac plexus neurolysis). Recently, the application of interventional EUS has been expanded to a new field, the treatment of gastrointestinal varices. There have been several studies examining this new technique for the treatment of esophageal and gastric varices. In the present review, we have summarized the current status of interventional EUS for the treatment of esophageal and gastric varices (e.g. EUS-guided coil deployment for gastric varices) and clarified the clinical feasibility of this procedure.

Achieving hemostasis and the risks associated with therapy

Acute gastrointestinal bleeding is a common cause for hospitalization. Endoscopic hemostasis plays a central role in the management of lesions with active bleeding or high-risk stigmata for rebleeding. The efficacy and safety of endoscopic hemostasis rely on the identification of lesions suitable for endoscopic therapy, selection of the appropriate hemostatic devices, attention to technique, and prompt recognition and management of procedure-related adverse events. In this article, practical applications of hemostatic devices and pitfalls related to endoscopic hemostasis are discussed.

Emerging endoscopic therapies for nonvariceal upper gastrointestinal bleeding

Several new devices and innovative adaptations of existing modalities have emerged as primary, adjunctive, or rescue therapy in endoscopic hemostasis of gastrointestinal hemorrhage. These techniques include over-the-scope clip devices, hemostatic sprays, cryotherapy, radiofrequency ablation, endoscopic suturing, and endoscopic ultrasound-guided angiotherapy. This review highlights the technical aspects and clinical applications of these devices in the context of nonvariceal upper gastrointestinal bleeding.

Application of cyanoacrylate in difficult-to-arrest acute non-variceal gastrointestinal bleeding

Gastrointestinal bleeding is a common medical emergency. Although endoscopic treatment is effective in controlling non-variceal upper gastrointestinal bleeding, in cases of persistent bleeding radiological or surgical interventions are required. Application of cyanoacrylate for treatment of difficult-to-arrest non-variceal upper gastrointestinal bleeding is poorly investigated. We describe patients in whom cyanoacrylate for acute non-variceal gastrointestinal bleeding was used to stop the bleeding after failure of conventional endoscopic treatment. Five patients were treated with cyanoacrylate application (injection and/or spraying) for persistent bleeding (duodenal ulcer in 3, gastric ulcer in 1 and gastric Dieulafoy's lesion in 1) despite conventional endoscopic therapies. Hemostasis was achieved in all patients (100%). One patient (20%) developed recurrent bleeding 4 days after initial treatment. No complications or adverse events attributed to the cyanoacrylate application during the follow-up period of 57 days were observed. Application of cyanoacrylate is a safe and effective method to achieve immediate hemostasis when conventional endoscopic treatment is unsuccessful. This technique is easy to perform and should be considered in cases of patients with difficult-to-arrest acute non-variceal upper gastrointestinal bleeding.

Interventional endoscopic ultrasonography

OPINION STATEMENT

Endoscopic ultrasound (EUS) is not only a diagnostic tool but also an interventional and therapeutic procedure. Indeed, in addition to tissue acquisition, it can also drain fluid collections adjacent to the gastrointestinal tract, provide access to biliary and pancreatic ducts, biliary, pancreatic, and gallbladder drainage, pancreatic cyst ablation, and, finally, provide anti-tumoral treatments and interventional vascular procedures. Although several improvements have been made in the last decade, the full potential of interventional EUS is yet to be completely explored. Future areas of research are the development of dedicated tools and accessories, the standardization of the interventional procedures, and the widening of the use of EUS, while increasing the expertise worldwide. In addition, more data, based on well-performed, possibly randomized clinical trials, are needed to accurately determine the risks and long-term outcomes of these interventions. We firmly believe that interventional EUS can play a pivotal role in anti-tumor treatments, by the fine-needle injection of anti-tumoral agents, tumor ablation, and assisting radiation treatment with gold fiducial placement and the implantation of intralesional seeds. The goal of the near future will be to offer targeted therapy and monitoring of tumor treatment response in a more biologically driven manner than has been available in the past. Interventional EUS will be an essential part of the multidisciplinary approach to cancer treatment.