Efficacy of a novel hemostatic adhesive powder in patients with upper gastrointestinal tumor bleeding

Biomedical applications of functional hydrogels: Innovative developments, relevant clinical trials and advanced products

Functional hydrogels are used for numerous biomedical applications such as tissue engineering, wound dressings, lubricants, contact lenses and advanced drug delivery systems. Most of them are based on synthetic or natural polymers forming a three-dimensional network that contains aqueous media. Among synthetic polymers, poly(meth)acrylates, polyethyleneglycols, poly(vinylalcohols), poly(vinylpyrrolidones), PLGA and poly(urethanes) are of high relevance, whereas natural polymers are mainly polysaccharides such as hyaluronic acid, alginate or chitosan and proteins such as albumin, collagen or elastin. In contrast to most synthetic polymers, natural polymers are biodegradable. Both synthetic and natural polymers are often chemically modified in order to improve or induce favorable properties and functions like high mechanical strength, stiffness, elasticity, high porosity, adhesive properties, in situ gelling properties, high water binding capacity or drug release controlling properties. Within this review we provide an overview about the broad spectrum of biomedical applications of functional hydrogels, summarize innovative approaches, discuss the concept of relevant functional hydrogels that are in clinical trials and highlight advanced products as examples for successful developments.

The efficacy of Hemospray in managing bleeding related to gastrointestinal tumors: systematic review and meta-analysis

INTRODUCTION

Gastrointestinal (GI) bleeding stemming from malignant tumors is increasingly recognized, due to advancements in oncology and detection methods. Traditional endoscopic hemostatic techniques have shown variable success rates in managing hemorrhagic GI neoplasms. Hemospray, an emerging endoscopic hemostatic powder, offers promise in treating upper GI bleeding, potentially extending its utility to neoplastic bleeding sites. This meta-analysis aims to evaluate Hemospray's efficacy in managing bleeding related to GI tumors.

METHODS

We searched Embase, Scopus, Web of Science, Medline/PubMed, and Cochrane. Inclusion criteria encompassed studies focusing on malignancy-related GI bleeding and interventions utilizing Hemospray. Comparative studies contrasted Hemospray with standard endoscopic treatments (SET), while noncomparative studies assessed Hemospray's efficacy independently. The risk of bias was assessed using appropriate tools, and statistical analyses were performed using Review Manager and open Meta analyst software.

RESULTS

We included 19 studies in our meta-analysis. Hemospray demonstrated higher rates of immediate hemostasis compared to SET (odds ratio: 17.14, 95% confidence interval: 4.27-68.86), with consistent outcomes across studies. Rebleeding rates at 14 and 30 days were comparable between Hemospray and SET groups, suggesting similar efficacy in long-term hemostasis. Hemospray showed a significantly lower need for nonendoscopic hemostasis compared to SET (odds ratio: 0.51, 95% confidence interval: 0.30-0.87), indicating a potential reduction in supplementary interventions. Safety assessments revealed no confirmed adverse events directly linked to Hemospray.

CONCLUSION

This meta-analysis highlights Hemospray's efficacy in achieving immediate hemostasis in GI tumor-related bleeding, with potential benefits in reducing supplementary interventions and improving patient outcomes. Despite comparable rebleeding rates, Hemospray emerges as a valuable adjunctive therapy in managing malignant GI bleeding.

Endoscopic Management of Tumor Bleeding: Techniques and Strategies

Endoscopic management of gastrointestinal (GI) tumor-related bleeding is challenging for many reasons including high rebleeding rates, poor tissue response to endoscopic therapies, altered wound healing and underlying coagulopathy. However, endoscopic treatment may help reduce transfusion requirements, avoid surgery, and provide a temporary bridge to oncologic therapy. This article explores various endoscopic techniques in managing tumor bleeding from more traditional approaches of using thermal or mechanical therapy with injection therapy to newer topical agents.

Hemostatic Powder vs Standard Endoscopic Treatment for Gastrointestinal Tumor Bleeding: A Multicenter Randomized Trial

BACKGROUND & AIMS

Current guidelines vary as to their recommendations addressing the role of hemostatic powders when managing patients with malignant gastrointestinal (GI) bleeding because these are based on very-low- to low-quality evidence, in large part due to a paucity of randomized trial data.

METHODS

This was a patient- and outcome assessor-blinded, multicenter, randomized controlled trial. Patients presenting with active bleeding from an upper or lower GI lesion suspected to be malignant at index endoscopy between June 2019 and January 2022 were randomly allocated to receive either TC-325 alone or standard endoscopic treatment (SET). The primary outcome was 30-day rebleeding, and secondary objectives included immediate hemostasis and other clinically relevant endpoints.

RESULTS

Overall, 106 patients made up the study population (55 TC-325 and 51 SET, after 1 exclusion in the TC-325 group and 5 in the SET group). Baseline characteristics and endoscopic findings did not differ between the groups. Thirty-day rebleeding was significantly lower in the TC-325 (2.1% TC-325 vs 21.3% SET; odds ratio, 0.09; 95% confidence interval [CI], 0.01-0.80; P = .003). Immediate hemostasis rates were 100% in the TC-325 group vs 68.6% in the SET group (odds ratio, 1.45; 95% CI, 0.93-2.29; P < .001). Other secondary outcomes did not differ between the 2 groups. Independent predictors of 6-month survival included the Charlson comorbidity index (hazard ratio, 1.17; 95% CI, 1.05-1.32; P = .007) and receiving an additional nonendoscopic hemostatic or oncologic treatment during 30 days after the index endoscopy (hazard ratio, 0.16; 95% CI, 0.06-0.43; P < .001) after adjustment for functional status, Glasgow-Blatchford score, and an upper GI source of bleeding.

CONCLUSION

The TC-325 hemostatic powder results in greater immediate hemostasis rates followed by lower 30-day rebleeding rates when compared to contemporary SET. (ClinicalTrials.gov, Number: NCT03855904).

Novel external reinforcement device for gastrointestinal anastomosis in an experimental study

BACKGROUND

Anastomotic leakage has been reported to occur when the load on the anastomotic site exceeds the resistance created by sutures, staples, and early scars. It may be possible to avoid anastomotic leakage by covering and reinforcing the anastomotic site with a biocompatible material. The aim of this study was to evaluate the safety and feasibility of a novel external reinforcement device for gastrointestinal anastomosis in an experimental model.

METHODS

A single pig was used in this non-survival study, and end-to-end anastomoses were created in six small bowel loops by a single-stapling technique using a circular stapler. Three of the six anastomoses were covered with a novel external reinforcement device. Air was injected, a pressure test of each anastomosis was performed, and the bursting pressure was measured.

RESULTS

Reinforcement of the anastomotic site with the device was successfully performed in all anastomoses. The bursting pressure was 76.1 ± 5.7 mmHg in the control group, and 126.8 ± 6.8 mmHg in the device group, respectively. The bursting pressure in the device group was significantly higher than that in the control group (p = 0.0006).

CONCLUSIONS

The novel external reinforcement device was safe and feasible for reinforcing the anastomoses in the experimental model.

Hemostatic powder for acute upper gastrointestinal bleeding: Recent research advances

Acute upper gastrointestinal bleeding (AUGIB) is a clinically common emergency condition. The common causes of AUGIB are peptic ulcer and esophagogastric variceal bleeding. Despite continuous improvements in endoscopic hemostasis techniques, endoscopic treatment is still unsuccessful in 5%-15% of patients. Hemostatic powder, a new drug for endoscopic hemostasis that is sprayed on the bleeding site with the assistance of an air pump, can absorb water to promote clotting substance aggregation and then adhere over the lesion, forming a mechanical barrier and then achieving hemostasis. It is convenient to spray hemostatic powder under endoscopy, where precise positioning is not warranted. The immediate hemostasis rate of hemostatic powder is often high, and it can be used as a remedy after the failure of conventional hemostasis. However, until now, there have been no recommendations in China regarding the use of hemostatic powder for the treatment of AUGIB. This article summarizes the mechanism, clinical applicability, and side effects of five major types of hemostatic powder by reviewing the existing evidence, with an aim to strengthen endoscopists' understanding of this drug.

Efficacy of topical hemostatic agents in malignancy-related GI bleeding: a systematic review and meta-analysis

BACKGROUND AND AIMS

Despite advances in endoscopic therapies, malignancy-related GI bleeding remains difficult to manage with high rates of treatment failure and rebleeding. Topical hemostatic agents (THAs) are easier to apply to the wide bleeding surface of tumors. We conducted this systematic review and meta-analysis to evaluate the efficacy of THAs in malignancy-related GI bleeding.

METHODS

We conducted a comprehensive search of multiple electronic databases to identify studies reporting on the use of THAs in malignancy-related GI bleeding. The primary outcome was the achievement of hemostasis; secondary outcomes were early rebleeding (≤3 days), delayed rebleeding (>3 days), aggregate rebleeding, all-cause mortality, and GI bleeding-related mortality. A meta-analysis of proportions was done for all outcomes.

RESULTS

Out of 355 citations, 16 studies with 530 patients were included. Primary hemostasis was achieved in 94.1% (95% confidence interval [CI], 91.5-96.0). Early rebleeding was seen in 13.9% (95% CI, 9.7-19.4) and delayed rebleeding in 11.4% (95% CI, 5.8-21.1). Aggregate rebleeding was seen in 24.2% (95% CI, 18.5-31.0). All-cause mortality was 33.1% (95% CI, 23.7-44.0), whereas GI bleeding-related mortality occurred in 5.9% (95% CI, 2.2%-14.8).

CONCLUSIONS

THAs are highly effective for achieving primary hemostasis in malignancy-related GI bleeding. It should be considered as an alternative to traditional endotherapy methods in malignancy-related GI bleeding. Future studies should be designed to evaluate its efficacy and safety as a primary method of hemostasis as compared with traditional endotherapy measures.

Hemostatic Powders in Non-Variceal Upper Gastrointestinal Bleeding: The Open Questions

Hemostatic powder (HP) is a relatively recent addition to the arsenal of hemostatic endoscopic procedures (HEPs) for gastrointestinal bleeding (GIB) due to benign and malignant lesions. Five types of HP are currently available: TC-325 (Hemospray™), EndoClot™, Ankaferd Blood Stopper^®, and, more recently, UI-EWD (Nexpowder^TM) and CEGP-003 (CGBio™). HP acts as a mechanical barrier and/or promotes platelet activation and coagulation cascade. HP may be used in combination with or as rescue therapy in case of failure of conventional HEPs (CHEPs) and also as monotherapy in large, poorly accessible lesions with multiple bleeding sources. Although the literature on HP is abundant, randomized controlled trials are scant, and some questions remain open. While HP is highly effective in inducing immediate hemostasis in GIB, the rates of rebleeding reported in different studies are very variable, and conditions affecting the stability of hemostasis have not yet been fully elucidated. It is not established whether HP as monotherapy is appropriate in severe GIB, such as spurting peptic ulcers, or should be used only as rescue or adjunctive therapy. Finally, as it can be sprayed on large areas, HP could become the gold standard in malignancy-related GIB, which is often nonresponsive or not amenable to treatment with CHEPs as a result of multiple bleeding points and friable surfaces. This is a narrative review that provides an overview of currently available data and the open questions regarding the use of HP in the management of non-variceal upper GIB due to benign and malignant diseases.

Efficacy analysis of hemostatic spray following endoscopic papillectomy: A multicenter comparative study

BACKGROUND AND AIM

Endoscopic post-papillectomy bleeding is a serious adverse event with a prevalence ranging from 2% to 45.3%. Conventional hemostatic methods, including diluted epinephrine injection before papillectomy or argon plasma coagulation after papillectomy, did not show a preventive role in reducing immediate or delayed post-papillectomy bleeding. Therefore, we aimed to assess the efficacy and safety of a hemostatic powder spray for post-papillectomy bleeding and compare with those of conventional modalities.

METHODS

Patients who underwent endoscopic papillectomy were enrolled in five tertiary hospitals. The group was divided into hemostatic spray and conventional control groups according to the bleeding control methods. The main outcome measurements were delayed bleeding rate and any adverse events related to the procedures.

RESULTS

A total of 40 patients who received a hemostatic spray (n = 18) or conventional hemostatic methods (n = 22) after endoscopic papillectomy were included. The prevalence of delayed bleeding was not different in the two groups: 27.8% and 36.4% in hemostatic spray and conventional control groups (P = 0.564), respectively. The adverse events such as post-papillectomy pancreatitis and cholangitis were not different in the two groups. There were no procedure-related mortalities.

CONCLUSION

Hemostatic spray is technically feasible and safe for the prevention or management of post-papillectomy bleeding. Hemostatic spray can be one of the options for post-papillectomy bleeding control methods owing to its convenient use.

TC-325 hemostatic powder in the management of upper gastrointestinal malignant bleeding: a randomized controlled trial

Background and study aims  Upper gastrointestinal bleeding (UGIB) from malignancy is associated with high rebleeding and mortality rates. Recently, TC-325 powder has shown promising results in the treatment of UGIB, including malignant bleeding. The aim of this study was to compare the efficacy of TC-325 versus best clinical management. Patients and methods  From August 2016 to February 2020, all patients with evidence of UGIB from malignancy were randomized to receive TC-325 therapy or control group, in which endoscopic treatment was not mandatory. Exclusion criteria were hemoglobin drop without overt bleeding and UGIB from non-tumor origin. The primary outcome was 30-day mortality. Secondary outcomes were 30-day rebleeding, blood transfusion and length of hospital stay. Results  Sixty-two patients were randomized, three were excluded and 59 were included in the final analysis (TC-325 group = 28; control = 31). Groups were similar at baseline. Active bleeding was observed in 22 patients in the TC-325 group and 19 in the control group ( P  = 0.15). Successful initial hemostasis with TC-325 was achieved in all cases. Additional therapy (radiotherapy, surgery or arterial embolization) was equally performed in both groups (42.9 % vs 58.1 %; P  = 0.243). There were no differences in 30-day mortality (28.6 % vs. 19.4 %, P  = 0.406) or 30-day rebleeding rates (32.1 % vs. 19.4 %, P  = 0.26). Logistic regression identified no significant predictors of rebleeding. Age, Eastern Cooperative Oncology Group (ECOG) score 3 to 4 and AIMS65 score > 1 predicted greater mortality. Conclusions  TC-325 was effective in achieving immediate hemostasis in malignant gastrointestinal bleeding but did not reduce 30-day mortality, 30-day rebleeding, blood transfusion or length of hospital stay. Age, ECOG 3-4, and AIMS65 > 1 were predictive factors of mortality.

Gastrointestinal Emergencies and the Role of Endoscopy

Many gastrointestinal (GI) disorders present to the emergency room with acute clinical presentations, some even life threatening. Common emergencies encountered that require urgent endoscopic interventions include GI hemorrhage (variceal and nonvariceal), foreign body ingestion, obstructive jaundice, postprocedure-related complications such as postpolypectomy bleed or perforation, etc. A major advantage of emergency endoscopy is that it is cost effective and, on many occasions, can be life-saving. The present review will highlight a practical approach on various endoscopic modalities and their use in the GI emergencies.

Hemostatic powders for gastrointestinal bleeding: a review of old, new, and emerging agents in a rapidly advancing field

Background and study aims  Hemostatic powders are increasingly used to address limitations in conventional endoscopic techniques for gastrointestinal bleeding. Various agents exist with different compositions, characteristics, efficacy, and adverse events (AEs). We sought to review existing hemostatic powders, from preclinical to established agents. Methods  A literature review on hemostatic powders for gastrointestinal bleeding was undertaken through a MEDLINE search from 2000-2021 and hand searching of articles. Relevant literature was critically appraised and reviewed for mechanism of action, hemostasis and rebleeding rate, factors associated with hemostatic failure, and AEs. Results  The most established agents are TC-325 (Hemospray), EndoClot, and Ankaferd Blood Stopper (ABS). These agents have been successfully applied to a variety of upper and lower gastrointestinal bleeding etiologies, in the form of primary, combination, salvage, and bridging therapy. Few AEs have been reported, including visceral perforation, venous embolism, and self-limited abdominal pain. Newer agents include CEGP-003 and UI-EWD, which have shown results similar to those for the older agents in initial clinical studies. All aforementioned powders have high immediate hemostasis rates, particularly in scenarios not amenable to conventional endoscopic methods, but are limited by significant rates of rebleeding. Other treatments include TDM-621 (PuraStat) consisting of a liquid hemostatic agent newly applied to endoscopy and self-propelling thrombin powder (CounterFlow Powder), a preclinical but promising agent. Conclusions  Rapid development of hemostatic powders and growing clinical expertise has established these agents as a valuable strategy in gastrointestinal bleeding. Further research will continue to refine the efficacy and applicability of these agents.

Hemostatic efficacy and safety of the hemostatic powder UI-EWD in patients with lower gastrointestinal bleeding

Background and aims

Acute lower gastrointestinal bleeding (LGIB) is a common cause of emergency hospitalization and may require readmission for re-bleeding. Recently, a novel endoscopic hemostatic powder (UI-EWD/Nexpowder™, Nextbiomedical, Incheon, South Korea) was developed and applied for the control of LGIB. The aim of this study was to evaluate the hemostatic efficacy and long-term safety of UI-EWD in LGIB.

Patients and methods

We conducted a retrospective cohort study of LGIB at a single tertiary center in south Korea. One hundred and sixty-seven consecutive patients with LGIB who were initially successful in endoscopic hemostasis were included and divided into the conventional treatment group (n = 112) and the UI-EWD therapy group (n = 55; 38 patients with conventional treatment and 17 patients with UI-EWD alone). The success rate of hemostasis, adverse events related to UI-EWD, and re-bleeding rate were evaluated.

Results

The incidence of endoscopic hemostasis applied to the hepatic flexure (7.3% vs. 0%, p = 0.011) and larger than 4 cm (25.5% vs. 8.0%, p = 0.002) were significantly higher in the UI-EWD group than in the conventional therapy group. The cumulative rebleeding rate within 28 days in the UI-EWD group was 5.5% (3/55), which was significantly lower than that in the conventional treatment group (17.0% [19/112]; p = 0.039). No UI-EWD-related adverse events were recorded.

Conclusion

Based on our results, application of UI-EWD in LGIB showed promising results for the prevention of re-bleeding, especially in locations where it is difficult to approach or cases with more bleeding. There were no significant complications, such as perforation or embolism. In particular, UI-EWD should be considered first for anatomical or technical impediments to endoscopic access in LGIB.

Risk Stratification in Cancer Patients with Acute Upper Gastrointestinal Bleeding: Comparison of Glasgow-Blatchford, Rockall and AIMS65, and Development of a New Scoring System

Background/Aims

Few studies have measured the accuracy of prognostic scores for upper gastrointestinal bleeding (UGIB) among cancer patients. Thereby, we compared the prognostic scores for predicting major outcomes in cancer patients with UGIB. Secondarily, we developed a new model to detect patients who might require hemostatic care.

Methods

A prospective research was performed in a tertiary hospital by enrolling cancer patients admitted with UGIB. Clinical and endoscopic findings were obtained through a prospective database. Multiple logistic regression analysis was performed to gauge the power of each score.

Results

From April 2015 to May 2016, 243 patients met the inclusion criteria. The AIMS65 (area under the curve [AUC] 0.85) best predicted intensive care unit admission, while the Glasgow-Blatchford score best predicted blood transfusion (AUC 0.82) and the low-risk group (AUC 0.92). All scores failed to predict hemostatic therapy and rebleeding. The new score was superior (AUC 0.74) in predicting hemostatic therapy. The AIMS65 (AUC 0.84) best predicted in-hospital mortality.

Conclusions

The scoring systems for prognostication were validated in the group of cancer patients with UGIB. A new score was developed to predict hemostatic therapy. Following this result, future prospective research should be performed to validate the new score.

An in situ catechol functionalized ε-polylysine/polyacrylamide hydrogel formed by hydrogen bonding recombination with high mechanical property for hemostasis

In situ hydrogel has attracted widely attention in hemostasis due to its ability to match irregular defects, but its application is limited by insufficient mechanical strength and long gelation time. Although some specifical in situ chemically cross-linked hydrogels could be fast formed and exhibit high mechanical strength, they unable to absorb blood. Hence their applications were further limited in emergency hemostasis usage. In this study, a robust hydrogel formed by hydration of powders was developed using multiple hydrogen bonds crosslinking. Here, catechol groups modified ε-polylysine (PL-CAT) and polyacrylamide (PAAM) were used to construct the PL-CAT/PAAM hydrogel. This hydrogel could be formed within 7 s to adhere and seal bleeding sites. The catechol groups endowed the hydrogel outstanding adhesive strength, which was 3.5 times of fibrin glue. Besides, the mechanical performance of in-situ PL-CAT/PAAM hydrogel was explored and the results showed that the hydrogel exhibited high compressive strength (0.47 MPa at 85% strain). Most importantly, the blood loss of wound treated with PL-CAT/PAAM hydrogel powders was 1/7 of untreated group, indicating the hydrogel's excellent hemostatic effect. And the cytotoxicity studies indicated that the PL-CAT/PAAM hydrogel had low toxicity. To summarize, this hydrogel could be a potential hemostatic material in emergency situations.