Endoscopic Delivery of Polymers Reduces Delayed Bleeding after Gastric Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis

Advancing hemostasis: A meta-analysis of novel vs conventional endoscopic therapies for non variceal upper gastrointestinal bleeding

BACKGROUND

Non variceal upper gastrointestinal bleeding (NVUGIB) is a life-threatening condition requiring prompt and effective hemostasis. Various endoscopic interventions, including novel hemostatic powders (HP), over-the-scope clips (OTSC), and traditional approaches, have been employed to manage upper gastrointestinal bleeding (UGIB). Despite advancements, comparative efficacy and safety of these modalities remain uncertain.

AIM

To evaluate the efficacy and safety of novel hemostatic interventions compared to conventional endoscopic techniques for managing UGIB.

METHODS

Cochrane, MEDLINE, PubMed and Scopus libraries were searched for randomized controlled trials (RCTs) published up to October 2024. Only RCTs comparing novel interventions, such as HP or OTSC, with conventional endoscopic treatments computed tomography (CT) were included. The primary outcome was the 30-day rebleeding rate. Secondary outcomes included initial hemostasis, short-term rebleeding rates, need for salvage therapy (surgical/angiographic), 30-day all-cause mortality, and bleeding-related mortality. We performed pairwise and network meta- analyses for all treatments.

RESULTS

Seventeen studies were included in this analysis. Regarding the 30-day rebleeding rate, OTSC and HP showed superior efficacy compared with CT [OTSC vs CT: Relative risk (RR): 0.47, 95% confidence interval (CI): 0.33-0.65; HP vs CT: RR: 0.73, 95%CI: 0.45-1.13], while OTSC and HP had comparable efficacy (RR: 0.56, 95%CI: 0.30-1.05). OTSC ranked the highest in the network ranking estimate for this outcome. For the secondary outcomes, OTSC demonstrated superior efficacy for the short-term rebleeding rate (OTSC vs CT: RR: 0.35, 95%CI: 0.14-0.74; HP vs CT: RR: 0.62, 95%CI: 0.28-1.35; OTSC vs HP: RR: 0.59, 95%CI: 0.17-1.67). Regarding the initial hemostasis rate, OTSC was slightly more effective than CT (OTSC vs CT: RR: 1.20, 95%CI: 1.06-1.57) and comparable to HP (OTSC vs HP: RR: 1.08, 95%CI: 0.89-1.40). There were no significant differences among treatments for all-cause mortality, bleeding-related mortality, or the necessity of surgical or angiographic salvage therapy. OTSC consistently ranked highest across most outcomes in the network ranking estimate.

CONCLUSION

This meta-analysis highlights OTSC as the most effective intervention for reducing 30-day and short-term rebleeding rates in NVUGIB, surpassing both CT and HP, supporting OTSC as a preferred first-line treatment for NVUGIB, while HP and CT remain viable alternatives. Further studies are needed to explore long-term outcomes and cost-effectiveness.

Closure strength of endoscopic hand-suturing in ex vivo porcine gastric ESD defect models: an exploratory animal study

BACKGROUND

Endoscopic hand-suturing (EHS) has been used to close gastrointestinal defects following endoscopic submucosal resection (ESD), but its closure strength needs further evaluation. This exploratory animal study aimed to compare the closure strength of EHS and titanium clips in ex vivo porcine gastric ESD defect models.

METHODS

Fifteen porcine stomachs were used to create ESD defect models, each featuring a 2-3-cm defect in the gastric body and another in the antrum. Defects were randomly assigned to three groups: EHS group (Group A), dense clipping group (Group B), and loose clipping group (Group C). Under endoscopy, Group A defects were sutured with 4 stitches, Group B with 7 clips, and Group C with 4 clips. The primary outcome measures were overall closure strength and closure strength per unit length, measured with a digital spring scale. Differences among groups were analyzed with the Kruskal-Wallis H test.

RESULT

All 30 defects were successfully closed endoscopically. Group A achieved significantly higher overall closure strength [1.06 kg (0.96 kg, 1.22 kg)] compared to Group B [0.27 kg (0.19 kg, 0.31 kg), P = 0.026] and Group C [0.11 kg (0.09 kg, 0.15 kg), P < 0.001]. For the closure strength per unit length, Group A [0.33 kg (0.27 kg, 0.35 kg)] also outperformed Group B [0.08 kg (0.06 kg, 0.10 kg), P = 0.023] and Group C [0.04 kg (0.03 kg, 0.04 kg), P < 0.001].

CONCLUSION

EHS can provide superior closure strength for ex vivo gastric ESD defects compared to simple titanium clips.

New Alternative? Self-Assembling Peptide in Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

BACKGROUND

Gastrointestinal bleeding (GIB) is a common and potentially fatal condition with all-cause mortality ranging from 3 to 10%. Endoscopic therapy traditionally involves mechanical, thermal, and injection therapies. Recently, self-assembling peptide (SAP) has become increasingly available in the United States. When applied to an affected area, this gel forms an extracellular matrix-type structure allowing for hemostasis. This is the first systematic review and meta-analysis to assess the safety and efficacy of this modality in GIB.

METHODS

We performed a comprehensive literature search of major databases from inception to Nov 2022. The primary outcomes assessed were the success of hemostasis, rebleeding rates, and adverse events. The secondary outcomes assessed were successful hemostasis with monotherapy with SAP and combined therapy, which may include mechanical, injection, and thermal therapies. Pooled estimates were calculated using random-effects models with a 95% confidence interval (CI).

RESULTS

The analysis included 7 studies with 427 patients. 34% of the patients were on anticoagulation or antiplatelet agents. SAP application was technically successful in all patients. The calculated pooled rate of successful hemostasis was 93.1% (95% confidence interval (CI) 84.7-97.0, I2 = 73.6), and rebleeding rates were 8.9% (95% CI 5.3-14.4, I2 = 55.8). The pooled rates of hemostasis with SAP monotherapy and combined therapy were similar. No adverse events were noted related to SAP.

CONCLUSION

SAP appears to be a safe and effective treatment modality for patients with GIB. This modality provides an added advantage of improved visualization over the novel spray-based modalities. Further, prospective, or randomized controlled trials are needed to validate our findings.

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions

Early gastric cancer comprises gastric malignancies that are confined to the mucosa or submucosa, irrespective of lymph node metastasis. Endoscopic resection is currently pivotal for the management of such early lesions, and it is the recommended treatment for tumors presenting a very low risk of lymph node metastasis. In general, these lesions consist of two groups of differentiated mucosal adenocarcinomas: non-ulcerated lesions (regardless of their size) and small ulcerated lesions. Endoscopic submucosal dissection is the technique of choice in most cases. This procedure has high rates of complete histological resection while maintaining gastric anatomy and its functions, resulting in fewer adverse events than surgery and having a lesser impact on patient-reported quality of life. Nonetheless, approximately 20% of resected lesions do not fulfill curative criteria and demand further treatment, highlighting the importance of patient selection. Additionally, the preservation of the stomach results in a moderate risk of metachronous lesions, which underlines the need for surveillance. We review the current evidence regarding the endoscopic treatment of early gastric cancer, including the short-and long-term results and management after resection.

Effect of particle size on the tissue adhesion and particle floatation of a colloidal wound dressing for endoscopic treatments

Endoscopic submucosal dissection (ESD) is a minimally invasive technique that is widely used to remove gastrointestinal tumors. However, because the walls of the duodenum and large intestine are thin, perforation can easily occur after ESD. We have previously reported that alkyl group-modified Alaska pollock gelatin-based microparticles (C10Ps) formed a colloidal gel that could adhere to defects and close perforations, driven by hydrophobic interactions. The present study focused on the effect of particle size on the colloidal gel properties and the floatation of C10Ps in the air in the delivery of C10Ps. We prepared C10Ps with different particle sizes from 0.1 to 100 µm. The storage modulus and adhesion strength of the C10P colloidal gel increased with decreasing particle size. All the C10Ps formed a colloidal gel layer on duodenum tissue after being sprayed from an endoscopic device. The underwater stability and burst strength of C10Ps with a particle size of 0.1 and 1 µm were higher than for larger C10Ps. Floating of the small-sized C10Ps in the air was observed. The results indicated that C10Ps with a size of 1 µm had suitable properties for use in endoscopic treatments. STATEMENT OF SIGNIFICANCE: We previously reported tissue adhesive microparticles as a spray-deliverable wound dressing in gastrointestinal tissues. However, their functions depending on particle size have not yet been clarified. In the present study, we prepared decyl group-modified Alaska pollock gelatin nano and microparticles (C10Ps) with different particle sizes from 0.1 to 100 µm and evaluated the effect of particle size on the colloidal gel properties (rheological property, underwater stability and perforation-closing ability) and the floatation of C10Ps in the air in the delivery of C10Ps.

Management of Adverse Events of Submucosal Endoscopy

The risk-benefit profile of submucosal endoscopic procedures is generally favorable but there exist unique considerations regarding the recognition, treatment, and prevention of submucosal endoscopic complications. Bleeding during the procedure can be managed with knife electrocautery, tamponade by injection of additional submucosal agent, or hemostatic forceps, depending on the location and degree of bleeding. Delayed bleeding should be managed with repeat endoscopy. Potential means to reduce the risk of delayed bleeding include anticipatory coagulation of visible vessels in the dissection ulcer base, applied hemostatic chemicals, snares, clips, and sheets of cultured cells.