Haemostasis and prevention of bleeding related to ER: The role of a novel self-assembling peptide

Colorectal endoscopic submucosal dissection in the USA: The current state and future perspectives

Endoscopic submucosal dissection (ESD) is a transformative advancement in the endoscopic management of superficial gastrointestinal lesions. Initially conceived for the treatment of early gastric cancer, ESD has demonstrated proficiency in achieving en-bloc resection of superficial gastrointestinal lesions. ESD has experienced widespread acceptance in Japan and East Asia; however, its adoption in the USA remains delayed. This initial hesitancy could be attributed to procedural complexity and training demands; nonetheless, recently, ESD has been gaining popularity in the USA. This is due to the advancements in endoscopic technology, tailored training programs, and cumulative evidence regarding the efficacy and safety of ESDs. This review aimed to deliberate the historical progress, current implementation, and prospective trajectory of ESDs in the USA. With ongoing clinical research, technological integration, and educational efforts, ESD is likely to become the gold standard for managing large gastrointesitinal lesions. This progress marks an imperative step toward less invasive, more precise, and patient-centric approaches regarding advanced therapeutic endoscopy in the USA.

Efficacy and feasibility of the RADA16 self-assembling peptide, PuraStat® for haemostasis in laparoscopic gynaecological surgery: A pilot study

Bleeding after laparoscopic gynaecological surgery remains a potential complication. We assessed RADA16 (PuraStat®), a topical self-assembling peptide haemostatic agent, in a pilot study of 46 women undergoing laparoscopic gynaecological surgery. The primary outcome was intraoperative haemostatic efficacy for resection site bleeding. Haemostasis was achieved in all intraoperative bleeding situations (40/40 participants: 100%) with no clinically significant surgical bed bleeding or complications. Mean volume and time required to achieve haemostasis were 6 mL and 14 sec, respectively. This study suggests that PuraStat® is a safe, effective haemostatic agent in laparoscopic gynaecological surgery. Randomised controlled trials are warranted to confirm these findings.

The use of a self-assembling peptide gel for stricture prevention in the esophagus after endoscopic submucosal dissection: a U.S. multicenter prospective study (with video)

BACKGROUND AND AIMS

Postoperative stricture is a serious common adverse event after extensive endoscopic submucosal dissection (ESD) in the esophagus. Self-assembling peptide (SAP) gel has been shown to promote tissue healing and re-epithelialization. The aim of this study was to evaluate the effect of the SAP gel for esophageal stricture prevention after ESD.

METHODS

This was a multicenter prospective study of patients who underwent esophageal ESD followed by SAP gel application between March 2022 and December 2023. Patients were included if the ESD mucosal defect involved ≥50% of the circumference of the esophagus. High-risk cases were defined as mucosal defects ≥75% of the circumference. Stricture was defined as the inability to pass an endoscope ≥8.9 mm in diameter or a narrow-caliber lumen in a patient with symptoms.

RESULTS

A total of 43 patients (median age, 71 years; 81.4% male) underwent ESD (median resected specimen size, 50 mm) during the study period. SAP gel (median, 3 mL) was successfully applied in all cases (median time, 4 minutes). In aggregate, stricture occurred in 20.9% (9 of 43) of the cases. Stricture developed in 30.8% of the high-risk cases: 80% (4 of 5) after circumferential ESD and 19% (4 of 21) in those with defects ≥75% but <100% of the circumference. All cases of stricture resolved with endoscopic treatment. Three cases (6.9%) of postoperative bleeding occurred and were adequately managed endoscopically.

CONCLUSIONS

We show that SAP gel application was easy, quick, and associated with a relatively low stricture rate comparable to other prophylactic methods. Additional comparative studies are needed to corroborate these preliminary findings.

Current otolaryngologic applications of the novel self-assembling RADA-16 peptide matrix

A novel bioresorbable agent on the market is PuraGel® (3-D Matrix, Tokyo, Japan), a RADA-16 product that acts as a synthetic hemostatic and space-filling gel that promotes wound healing and prevents adhesion formation. Given the reported benefits of accelerated wound healing and scar tissue prevention, there are multiple otolaryngologic applications where RADA-16 might improve outcomes. Our study highlights current utilization and associated post-operative complications with this product.

Systematic review of self-assembling peptides as topical agents for treatment and prevention of gastrointestinal bleeding

BACKGROUND/AIMS

Gastrointestinal bleeding is a significant and potentially lethal event. We aimed to review the efficiency and safety of self-assembling peptides for the treatment and prevention of gastrointestinal tract bleeding.

METHODS

We conducted a systematic search for studies describing the endoscopic use of self-assembling peptides for treatment or prevention of bleeding in the gastrointestinal tract in a parallel, independent fashion. The primary outcomes were rates of successful initial hemostasis, delayed bleeding, and rebleeding. The secondary outcomes were adverse events and ease and volume of gel used.

RESULTS

Seventeen studies were analyzed. Overall success rate of self-assembling peptides in gastrointestinal bleeding was 87.7% (38%-100%), regardless of etiology or associated treatments. Rebleeding rate ranged from 0% to 16.2%, with a mean of 4.7%, and overall delayed bleeding rate was 5% (range, 0%-15.9%). Only three adverse events were reported in a pooled number of 815 patients. The volume of gel used varied (0.43 to 3.7 mL) according to indication and type of bleeding.

CONCLUSIONS

The limited available data on the use of self-assembling peptides in gastrointestinal endoscopy suggest a high efficiency and good safety profile.

Spray coagulation reduces the use of hemostatic forceps for intraoperative bleeding in gastric endoscopic submucosal dissection

Aims

During intraoperative bleeding in endoscopic submucosal dissection (ESD), switching to spray coagulation may be beneficial compared with the continuous use of swift coagulation and can reduce the need for hemostatic forceps. We retrospectively assessed the effectiveness of spray modes on intraoperative bleeding during gastric ESD.

Methods and Results

A total of 316 bleeding events (156 in the Swift group and 160 in the Spray group) were consecutively recorded. In the Swift group, hemostasis was performed using the swift mode with a retracted tip of the needle-type knife, followed by the hemostatic forceps. In the Spray group, bleeding was treated in a stepwise manner: the swift mode, the spray mode, and the hemostatic forceps. All bleeding events were assigned to one of two groups by an endoscopist who retrospectively reviewed the videos. We compared the use of hemostatic forceps, the total hemostatic time, and the cumulative hemostasis rate between the two groups.The use of hemostatic forceps was significantly lower in the Spray group than in the Swift group (32.7% vs. 13.8%, P < 0.001). There was no significant difference in the total hemostatic time (Swift group, 20 s.; Spray group, 16 s.; P = 0.42), whereas the cumulative hemostasis rate with the knife was significantly higher in the Spray group (P = 0.007).

Conclusion

The results suggested that spray coagulation from the tip of the needle-type knife could reduce the use of hemostatic forceps. In gastric ESD, spray coagulation may facilitate the hemostasis of intraoperative bleeding.

Duodenal Papillary Metastasis of Lung Cancer with Bleeding Controlled by Endoscopic Treatment and Systemic Osimertinib Therapy: Case Report

Introduction

Solid organ malignancies rarely metastasize to the duodenal papilla. We describe a case of primary lung cancer with duodenal papillary metastasis in a patient who presented with melena. To the best of our knowledge, this is only the second report of duodenal papillary metastasis from lung cancer.

Case Presentation

A 65-year-old woman presented with complaints of anorexia, weight loss, and black stool. Imaging studies led to a clinical diagnosis of stage IVB lung cancer, and anticoagulants were initiated to treat pulmonary artery thrombosis. However, endoscopic hemostasis was challenging because of bleeding from a duodenal papillary tumor. Fortunately, the patient was positive for the plasma epidermal growth factor receptor (EGFR) gene mutation, and osimertinib, an EGFR tyrosine kinase inhibitor, was administered, successfully achieving hemostasis. Subsequently, endoscopic ultrasonography-guided transbronchial needle aspiration of an enlarged mediastinal lymph node and duodenal papillary tumor biopsy confirmed duodenal papillary metastasis of the primary lung adenocarcinoma.

Conclusion

Although duodenal papillary metastasis is extremely rare, a good clinical outcome was achieved in this case by considering duodenal papillary metastasis from lung cancer as the differential diagnosis and administering systemic osimertinib therapy.

Efficacy of hemostatic gel for perioperative bleeding and prevention of delayed bleeding of cold snare polypectomy under anticoagulant

Background and Aim

A hemostatic gel, PuraStat (3-D Matrix, Tokyo, Japan), is used for various gastrointestinal hemostasis. In this study, we analyzed the efficacy of PuraStat for perioperative bleeding (POB) and prevention of delayed bleeding (DB) to colorectal cold snare polypectomy (CSP) with continuous anticoagulant.

Methods

This was a single-center, retrospective study. Subjects were lesions of 2-9 mm under continuous anticoagulant from 2021 to 2023 and treated with PuraStat for POB. The definition of POB was bleeding which did not stop spontaneously by 1.0-1.5 min after resection and needed hemostasis. Successful hemostasis was defined as cessation of bleeding within 1.0-1.5 min after spraying PuraStat and the rate of it and risk factors of POB were analyzed. For comparison, cases receiving previous CSP without PuraStat were extracted from all cases with CSP (2018-2021), and POB and DB rate (DBR) were analyzed after propensity score matching.

Results

One hundred twenty-two lesions (91: direct oral anticoagulant (DOAC), 31: warfarin) with anticoagulant were analyzed and the rate of successful hemostasis with PuraStat was 92.6% (DOAC/warfarin: 93.4%/80.6%, P = 0.01). The rate of DB was 0.0%. Multivariate analysis showed that significant risk factors about unsuccessful hemostasis for POB with PuraStat were lesion size 8-9 mm (P < 0.01), warfarin (P = 0.01), and combination of antiplatelet (P = 0.01). Regarding the comparison about CSP with/without PuraStat, the clipping rate and DBR were 8.5%/94.9% (P < 0.01) and 0%/1.7% (P = 1.0).

Conclusion

The effects of PuraStat for POB and DB in colorectal CSP with continuous anticoagulant were acceptable.

Endoscopic Management of Bleeding in Altered Anatomy after Upper Gastrointestinal Surgery

Postoperative non variceal upper gastrointestinal haemorrhage may occur early or late and affect a variable percentage of patients-up to about 2%. Most cases of intraluminal bleeding are an indication for urgent Esophagogastroduodenoscopy (EGD) and require endoscopic haemostatic treatment. In addition to the approach usually adopted in non-variceal upper haemorrhages, these cases may be burdened with difficulties in terms of anastomotic tissue, angled positions, and the risk of further complications. There is also extreme variability related to the type of surgery performed, in the context of oncological disease or bariatric surgery. At the same time, the world of haemostatic devices available in digestive endoscopy is increasing, meeting high efficacy rates and attempting to treat even the most complex cases. Our narrative review summarises the current evidence in terms of different approaches to endoscopic haemostasis in upper bleeding in altered anatomy after surgery, proposing an up-to-date guidance for endoscopic clinicians and at the same time, highlighting areas of future scientific research.

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.

Short Peptide Nanofiber Biomaterials Ameliorate Local Hemostatic Capacity of Surgical Materials and Intraoperative Hemostatic Applications in Clinics

Short designer self-assembling peptide (dSAP) biomaterials are a new addition to the hemostat group. It may provide a diverse and robust toolbox for surgeons to integrate wound microenvironment with much safer and stronger hemostatic capacity than conventional materials and hemostatic agents. Especially in noncompressible torso hemorrhage (NCTH), diffuse mucosal surface bleeding, and internal medical bleeding (IMB), with respect to the optimal hemostatic formulation, dSAP biomaterials are the ingenious nanofiber alternatives to make bioactive neural scaffold, nasal packing, large mucosal surface coverage in gastrointestinal surgery (esophagus, gastric lesion, duodenum, and lower digestive tract), epicardiac cell-delivery carrier, transparent matrix barrier, and so on. Herein, in multiple surgical specialties, dSAP-biomaterial-based nano-hemostats achieve safe, effective, and immediate hemostasis, facile wound healing, and potentially reduce the risks in delayed bleeding, rebleeding, post-operative bleeding, or related complications. The biosafety in vivo, bleeding indications, tissue-sealing quality, surgical feasibility, and local usability are addressed comprehensively and sequentially and pursued to develop useful surgical techniques with better hemostatic performance. Here, the state of the art and all-round advancements of nano-hemostatic approaches in surgery are provided. Relevant critical insights will inspire exciting investigations on peptide nanotechnology, next-generation biomaterials, and better promising prospects in clinics.

Efficacy of a novel self-assembling peptide gel for hemostasis in refractory neoplastic bleeding

Video 1Outline of how self-assembling peptide gel can be used ex vivo.

Emergency Endoscopic Hemostasis for Gastrointestinal Bleeding Using a Self-Assembling Peptide: A Case Series

Background and Objectives: A novel synthetic self-assembling peptide, PuraStat, has been introduced as a hemostatic agent. This case series aimed to evaluate the clinical efficacy of PuraStat for gastrointestinal bleeding during emergency endoscopy. Cases: Twenty-five patients with gastrointestinal bleeding who had undergone emergency endoscopy with PuraStat between August 2021 and December 2022 were retrospectively examined. Six patients were receiving antithrombotic agents, and ten patients with refractory gastrointestinal bleeding had undergone at least one endoscopic hemostatic procedure. The breakdown of bleeding was gastroduodenal ulcer/erosion in 12 cases, bleeding after gastroduodenal or colorectal endoscopic resection in 4 cases, rectal ulcer in 2 cases, postoperative anastomotic ulcer in 2 cases, and gastric cancer, diffuse antral vascular ectasia, small intestinal ulcer, colonic diverticular bleeding, and radiation proctitis in each case. The method of hemostasis was only PuraStat application in six cases, and hemostasis in combination with high-frequency hemostatic forceps, hemostatic clip, argon plasma coagulation, and hemostatic agents (i.e., thrombin) in the remaining cases. Rebleeding was observed in three cases. Hemostatic efficiency was observed in 23 cases (92%). Conclusions: PuraStat has the expected hemostatic effect on gastrointestinal bleeding during emergency endoscopy. The use of PuraStat should be considered in emergency endoscopic hemostasis of gastrointestinal bleeding.

Efficacy of self-assembling peptide in mitigating delayed bleeding after advanced endoscopic resection of gastrointestinal lesions: A meta-analysis

Background and study aims  Advanced endoscopic resection techniques carry a risk of delayed bleeding (DB). A novel fully synthetic self-assembling peptide (SAP) has shown promising results in mitigating this risk. In this meta-analysis, we evaluated all available data and analyzed the effectiveness of SAP in reducing DB after advanced endoscopic resection of gastrointestinal luminal lesions. Patients and methods  Electronic databases (PubMed, Embase, and Cochrane Library) from January 2010 through October 2022 were searched for publications addressing the use of SAP solution in patients undergoing advanced endoscopic resection of gastrointestinal lesions. Pooled proportions were calculated using fixed (inverse variance) and random-effects (DerSimonian-Laird) models. Results  The initial search identified 277 studies, of which 63 relevant articles were reviewed. The final analysis included data from six studies comprising 307 patients that met inclusion criteria. The pooled rate of DB was 5.73 % (95 % confidence interval [CI] = 3.42-8.59). Mean patient age was 69.40 years ± 1.82. The weighted mean size of resected lesions was 36.20 mm (95 % CI = 33.37-39.02). Endoscopic submucosal dissection was used in 72.69 % (95 % CI = 67.62-77.48), while endoscopic mucosal resection was used in 26.42 % (95 % CI = 21.69-31.44) of the procedures. Among the 307 patients, 36 % were on antithrombotic medications. No adverse events (AEs) were attributable to using SAP, with a pooled rate of 0.00 % (95 % CI = 0.00-1.49). Conclusions  SAP solution appears promising in reducing post-procedural DB after advanced endoscopic resection of high-risk gastrointestinal lesions with no reported AEs.

Endoscopic Hemostatic Treatment for Acute Gastrointestinal Bleeding by Combined Modality Therapy with PuraStat and Endoscopic Hemoclips

Acute gastrointestinal bleeding (AGIB) is a common condition leading to hospitalization and is associated with significant morbidity and mortality. Various endoscopic treatments have been reported for AGIB, while its endoscopic hemostasis treatment by combined modality with PuraStat and endoscopic hemoclips remains less well documented. We report 6 cases of AGIB, i.e., 5 cases of ulcer bleeding and 1 case of ruptured gastric varices in 3 males and 3 females aged 49-97 years (mean age, 77 years), 2 and 1 of whom had been on antithrombotic drugs and nonsteroidal anti-inflammatory drugs, respectively, with 2 of these found to be in critical condition with hemorrhagic shock. Types of bleeding treated included oozing bleeding from visible vessels (n = 3), spurting bleeding from visible vessels (n = 2) and from gastric varices (n = 1). In all cases, complete hemostasis was achieved with no rebleeding. To our knowledge, this report represents a valuable addition to the AGIB literature describing endoscopic hemostasis by combined modality therapy with PuraStat and endoscopic hemoclips.

JAG consensus statements for training and certification in flexible sigmoidoscopy

Introduction

Joint Advisory Group (JAG) certification in endoscopy is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update standards for training and certification in flexible sigmoidoscopy (FS).

Methods

A modified Delphi process was conducted between 2019 and 2020 with multisociety representation from experts and trainees. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on FS training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer-reviewed by national stakeholders for incorporation into the JAG FS certification pathway.

Results

In total, 41 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (17), assessment of competence (7) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (A) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, rectal retroversion >90%, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (B) minimum procedure count ≥175; (C) performing 15+ procedures over the preceding 3 months; (D) attendance of the JAG Basic Skills in Lower gastrointestinal Endoscopy course; (E) satisfying requirements for formative direct observation of procedural skill (DOPS) and direct observation of polypectomy skill (SMSA level 1); (F) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool and (G) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in FS have been updated to support training, uphold standards in FS and polypectomy, and provide support to the newly independent practitioner.

JAG consensus statements for training and certification in colonoscopy

Introduction

In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification.

Methods

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway.

Results

In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate–severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

Endoscopic Management Using Novel Haemostatic Agents for Immediate Bleeding during Endoscopic Retrograde Cholangio-Pancreatography

Bleeding after endoscopic sphincterotomy (ES) remains as a major challenge during ERCP procedure. Standard endoscopic haemostatic procedures have demonstrated good performance for bleeding control. Novel endoscopic haemostatic agents have also been widely used in gastrointestinal bleeding management. Regardless, there is still a paucity of high-quality evidence evaluating the practicality of these agents in ERCP. This case series study was performed on the patients who underwent ERCP procedure in a tertiary referral private hospital within 2 years period. Post-ES immediate bleeding is defined as the onset of bleeding at the time of sphincterotomy. Treatment groups for post-ES bleeding are divided into (1) standard haemostatic methods and (2) novel haemostatic agents. There were 40 patients who received standard haemostatic treatment and 60 patients who received novel haemostatic agents. Initial haemostasis was achieved in all patients. Two patients who received standard haemostatic treatment had rebleeding. Meanwhile, no patients in novel haemostatic treatment group had rebleeding. In conclusion, novel haemostatic agent can be considered as an easy and practical method in daily practice, especially when an ERCP procedure is performed. Further studies with larger sample size which, if possible, can also include a cost-effectiveness analysis are still required to implement these agents as a standard procedure in clinical practice. (This abstract has been presented at the American College of Gastroenterology meeting October 2021).

Effectiveness and safety of a newly designed self-assembling gel in the treatment of endoscopic submucosal dissection-induced gastric ulcer: A multicenter randomized controlled trial

Objectives: To evaluate the effectiveness and safety of a newly designed self-assembling gel in treating ESD-induced gastric ulcers in patients.

Methods: This open-label, multicenter, randomized controlled trial enrolled patients who underwent ESD between September 2020 and May 2021. Patients were randomized (1:1) to receive the gel (applied to cover the entire ulcer bed under endoscopic guidance immediately after ESD; gel group) or not (control group). The primary outcome was the ulcer healing rate at 28 days. And the secondary outcomes were the delayed bleeding, changes in the ulcer stage, and adverse events.

Results: Finally, 125 patients (mean age, 63.7 years; 70 [56.0%] males) were enrolled. The ulcer healing rate was higher in the gel group than in the control group at 28 days (96.9 ± 4.1% vs. 94.7 ± 5.0%; p = 0.001). The ulcer reduction rate at 28 days differed significantly (p &lt; 0.001) between ulcers with majority gel coverage (99.8%), ulcers with minority gel coverage (96.2%), and ulcers with no gel coverage (98.0%). Delayed bleeding was found in 1/63 gel-treated patients (1.6%) versus 5/62 controls (8.1%). A1-stage ulcers were found in 16/63 patients in the gel group versus 44/62 patients in the control group (25.4% vs. 71.0%, p &lt; 0.001) at 3–5 days.

Conclusion: The newly developed self-assembling gel was safe and effective in accelerating gastric ulcer healing in patients after ESD.

Clinical Trial Registration: UMIN Clinical Trials Registry System (registration number, ChiCTR2100052935).

Preventing Postendoscopic Mucosal Resection Bleeding of Large Nonpedunculated Colorectal Lesions

The most common major adverse event of endoscopic mucosal resection (EMR) is clinically significant post-EMR bleeding (CSPEB), with an incidence of 6%-7% in large lesions. Repeat colonoscopy, blood transfusions, or other interventions are often needed. The associated direct costs are much higher than those of an uncomplicated EMR. In this review, we discuss the aspects related to CSPEB of large nonpedunculated polyps, such as risk factors, predictive models, and prophylactic measures, and we highlight evidence for preventive treatment options and explore new methods for bleeding prophylaxis. We also provide recommendations for steps that can be taken before, during, and after EMR to minimize bleeding risk. Finally, this review proposes future directions to reduce CSPEB incidence.

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

New endoscopic approaches for the prevention of delayed bleeding (DB) after gastric endoscopic submucosal dissection (ESD) have been reported in recent years, and endoscopic delivery of biodegradable polymers for iatrogenic ulcer hemostasis and coverage has emerged as one of the most promising techniques for post-ESD management. However, the comparative efficacy of these techniques remains uncertain. We performed a systematic search of multiple databases up to May 2022 to identify studies reporting DB rates as outcomes in patients undergoing gastric ESD who were treated with subsequent endoscopic management, including endoscopic closure (clip-based methods and suturing), PGA sheet tissue shielding, and hemostatic powder/gel spray (including polymeric sealants and other adhesives). The risk ratios (RRs) of delayed bleeding in treatment groups and control groups were pooled, and the Bayesian framework was used to perform a network meta-analysis (NMA). Among these studies, 16 head-to-head comparisons that covered 2742 lesions were included in the NMA. Tissue shielding using PGA sheets significantly reduced the risk of DB by nearly two thirds in high-risk patients, while hemostatic spray systems, primarily polymer-based, reduced DB in low-risk patients nine-fold. Researchers should recognize the essential role of polymers in the management of ESD-induced ulcers, and develop and validate clinical application strategies for promising materials.

Engineered Molecular Therapeutics Targeting Fibrin and the Coagulation System: a Biophysical Perspective

The coagulation cascade represents a sophisticated and highly choreographed series of molecular events taking place in the blood with important clinical implications. One key player in coagulation is fibrinogen, a highly abundant soluble blood protein that is processed by thrombin proteases at wound sites, triggering self-assembly of an insoluble protein hydrogel known as a fibrin clot. By forming the key protein component of blood clots, fibrin acts as a structural biomaterial with biophysical properties well suited to its role inhibiting fluid flow and maintaining hemostasis. Based on its clinical importance, fibrin is being investigated as a potentially valuable molecular target in the development of coagulation therapies. In this topical review, we summarize our current understanding of the coagulation cascade from a molecular, structural and biophysical perspective. We highlight single-molecule studies on proteins involved in blood coagulation and report on the current state of the art in directed evolution and molecular engineering of fibrin-targeted proteins and polymers for modulating coagulation. This biophysical overview will help acclimatize newcomers to the field and catalyze interdisciplinary work in biomolecular engineering toward the development of new therapies targeting fibrin and the coagulation system.

Endoscopic Management for Post-Surgical Complications after Resection of Esophageal Cancer

Simple Summary

Flexible endoscopy has an important part in the diagnosis and treatment of postoperative complications after oncologically intended esophagectomy. Endoscopy offers the possibility of effective therapy with minimal invasiveness at the same time, and the use of endoscopic therapy procedures can avoid re-operations. In this review we present the advantages of endoscopic treatment opportunities during the last 20 years regarding patients’ treatment after esophageal cancer resection. According to prevalence and clinical relevance, four relevant postoperative complications were identified and their endoscopic treatment procedures discussed. All endoscopic therapy procedures for anastomotic bleeding, anastomotic insufficiencies, anastomotic stenosis and postoperative delayed gastric emptying are presented, including innovative developments.

Abstract

Background: Esophageal cancer (EC) is the sixth-leading cause of cancer-related deaths in the world. Esophagectomy is the most effective treatment for patients without invasion of adjacent organs or distant metastasis. Complications and relevant problems may occur in the early post-operative course or in a delayed fashion. Here, innovative endoscopic techniques for the treatment of postsurgical problems were developed during the past 20 years. Methods: Endoscopic treatment strategies for the following postoperative complications are presented: anastomotic bleeding, anastomotic insufficiency, delayed gastric passage and anastomotic stenosis. Based on a literature review covering the last two decades, therapeutic procedures are presented and analyzed. Results: Addressing the four complications mentioned, clipping, stenting, injection therapy, dilatation, and negative pressure therapy are successfully utilized as endoscopic treatment techniques today. Conclusion: Endoscopic treatment plays a major role in both early-postoperative and long-term aftercare. During the past 20 years, essential therapeutic measures have been established. A continuous development of these techniques in the field of endoscopy can be expected.

"PP-type" self-assembling peptides with superior rheological properties

The ionic-complementary self-assembling peptides discovered by Zhang Shuguang have solution-to-gel (sol-gel) transition capacity and one such peptide RADA16 has been commercialized into hemostatic agents. However, their sol-gel transition ability was not obvious because the peptide aqueous solution with a concentration greater than 1% w/v appeared to be thick and viscous. The current report describes PP-type self-assembling peptides. In addition to the ionic-complementary sequence, they have prolines at both ends of the sequence. This feature has led to better solubility, lower viscosity of the peptide solution, and simplified synthesis and purification processes while maintaining the great gelling performance of the ionic-complementary peptides. The PP-type peptides self-assembled into a well-organized nanofiber scaffold as shown by TEM. Among the PP-type peptides, the PRVDP9 sequence peptide was tested as a hemostatic agent and a mucosal elevating agent. The results were comparable to the classic RADA16. The PP-type self-assembling peptides have superior sol-gel transition ability. Therefore, it is predicted that they will be more suitable to be transported through catheters or endoscopes and have higher commercialization potential as compared with the classic self-assembling peptide sequences.

Efficacy of hemostatic powders in lower gastrointestinal bleeding: Clinical series and literature review

BACKGROUND

There is limited evidence on the efficacy of hemostatic powders in the management of lower gastrointestinal bleeding.

AIMS

to revise our series of patients with lower gastrointestinal bleeding treated with hemostatic powders and to provide a pooled estimate of their efficacy based on the current literature.

METHODS

Sixty-five patients underwent topical endoscopic application of hemostatic powder between 2016 and 2020. The primary endpoint was treatment success, with 7- and 30-day rebleeding rate, adverse events and mortality as secondary outcomes. Literature review was based on computerized bibliographic search on the main databases through December 2020. Pooled effects were calculated using a random-effects model.

RESULTS

Overall, the powder was applied as monotherapy in 37 patients (56.9%), as combination therapy in 15 patients (23.4%), and as rescue therapy in 13 cases (19.9%). Hemostasis was achieved in 100% of patients. Rebleeding rate at 7- and 30-day was 7.7% and 9.2%, respectively. A total of 10 studies with 259 patients were included in the meta-analysis. Immediate hemostasis was achieved in 96.3% (93.4%-99.2%) patients, whereas pooled 7- and 30-day rebleeding rates were 9.6% (4.5%-14.6%) and 12.9% (7.2%-18.5%), respectively.

CONCLUSION

Novel hemostatic powders represent a user-friendly and effective tool in the management of lower gastrointestinal bleeding.

The feasibility of a novel injectable hydrogel for protecting artificial gastrointestinal ulcers after endoscopic resection: an animal pilot study

Recently, covering materials for protecting post-endoscopic ulcers are being developed using hydrogels. Existing hydrogels are not ideal coating materials because it is difficult to control their physical properties. Therefore, we conducted an animal pilot study to investigate the protective effect of a novel ulcer coating material, whose physical properties can be easily controlled and designed. We applied the novel injectable hydrogel to artificial ulcers induced on the gastric mucosa of rats. Rats were assigned to the hydrogel or the control group. To measure the protective effect of hydrogel on ulcers, the perforation rate, ulcer diameter, and ulcer area were evaluated 48 h after gel application. As secondary endpoints, we assessed the residual rate of the hydrogel at the bottom of the ulcer, performed histological analysis, and analyzed adverse events associated with hydrogel. The perforation rate was significantly lower (16% vs. 75%) and the mean diameter of ulcers was significantly smaller (5.4 ± 1.8 mm vs. 7.8 ± 2.8 mm) in the hydrogel group. Histopathological findings revealed the inflammatory cell count was significantly higher in the control group. Our novel hydrogel showed a protective effect on artificial gastric ulcers in a rat model.

Self-assembling peptide haemostatic gel reduces incidence of pelvic collection after total mesorectal excision: Prospective cohort study

BACKGROUND

Pelvic surgery has the potential to leave behind a large raw surface, which can bleed and ooze postoperatively. The adoption of precision surgical approach for rectal cancers has led to reduction in blood loss. We aimed to assess 1) the feasibility and 2) the safety of using a self-assembling peptide (SAP) haemostatic agent (PuraStat®) after rectal cancer surgery to reduce the incidence of pelvic collections.

MATERIALS AND METHODS

This prospective cohort pilot study compared the results of 25 consecutive cases of total mesorectal excision (TME) with use of 5-10 ml of SAP, and 25 consecutive cases without PuraStat® application (CON, control group). The groups were compared for complications (Clavien-Dindo grade III and IV classification), postoperative drain output and length of hospital stay (LOS). Statistical analysis was carried out using paired samples T test and Fisher's exact test.

RESULTS

Fifty patients (SAP = 25, CON = 25) were enrolled into this study. Mean drain outputs (ml) on day 1, day 2 and day 3 were 60 ± 18, 89 ± 42 and 64 ± 45 in SAP group, and 102 ± 31, 95 ± 52, 66 ± 37 in CON group. This was significantly better for SAP group in day one after surgery. The mean LOS was shorter in SAP group (5.7 versus 7.4 days in CON, p 0.04). Clavien-Dindo III & IV complications were seen in two and five cases respectively (p 0.18). R0 resection rate (p 0.32) and lymph node harvest (p 0.13) were similar in both groups. There were no complications seen in relation to the application of the SAP.

CONCLUSIONS

These initial data suggest that SAP is a safe product, and feasible to apply in the pelvis after TME surgery. It appears to shorten the LOS and reduce the postoperative drain output and may reduce the incidence of Clavien-Dindo grade III & IV complications.

PuraStat in gastrointestinal bleeding: results of a prospective multicentre observational pilot study

Background

A recently developed haemostatic peptide gel for endoscopic application has been introduced to improve the management of gastrointestinal bleeding. The aim of this pilot study was to evaluate the feasibility, safety, efficacy and indication profiles of PuraStat in a clinical setting.

Methods

In this prospective observational multicentre pilot study, patients with acute non-variceal gastrointestinal bleeding (upper and lower) were included. Primary and secondary application of PuraStat was evaluated. Haemoglobin, prothrombin time, platelets and transfusion behaviour were documented before and after haemostasis. The efficacy of PuraStat was assessed during the procedure, at 3 days and 1 week after application.

Results

111 patients with acute gastrointestinal bleeding were recruited into the study. 70 percent (78/111) of the patients had upper gastrointestinal bleeding and 30% (33/111) had lower gastrointestinal bleeding. After primary application of PuraStat, initial haemostatic success was achieved in 94% of patients (74/79, 95% CI 88–99%), and in 75% of the patients when used as a secondary haemostatic product, following failure of established techniques (24/32, 95% CI 59–91%). The therapeutic success rates (absence of rebleeding) after 3 and 7 days were 91% and 87% after primary use, and 87% and 81% in all study patients. Overall rebleeding rate at 30 day follow-up was 16% (18/111). In the 5 patients who finally required surgery (4.5%), PuraStat allowed temporary haemostasis and stabilisation.

Conclusions

PuraStat expanded the therapeutic toolbox available for an effective treatment of gastrointestinal bleeding sources. It could be safely applied and administered without complications as a primary or secondary therapy. PuraStat may additionally serve as a bridge to surgery in order to achieve temporary haemostasis in case of refractory severe bleeding, possibly playing a role in preventing immediate emergency surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08589-6.

Clinical Use of the Self-Assembling Peptide RADA16: A Review of Current and Future Trends in Biomedicine

RADA16 is a synthetic peptide that exists as a viscous solution in an acidic formulation. In an acidic aqueous environment, the peptides spontaneously self-assemble into β-sheet nanofibers. Upon exposure and buffering of RADA16 solution to the physiological pH of biological fluids such as blood, interstitial fluid and lymph, the nanofibers begin physically crosslinking within seconds into a stable interwoven transparent hydrogel 3-D matrix. The RADA16 nanofiber hydrogel structure closely resembles the 3-dimensional architecture of native extracellular matrices. These properties make RADA16 formulations ideal topical hemostatic agents for controlling bleeding during surgery and to prevent post-operative rebleeding. A commercial RADA16 formulation is currently used for hemostasis in cardiovascular, gastrointestinal, and otorhinolaryngological surgical procedures, and studies are underway to investigate its use in wound healing and adhesion reduction. Straightforward application of viscous RADA16 into areas that are not easily accessible circumvents technical challenges in difficult-to-reach bleeding sites. The transparent hydrogel allows clear visualization of the surgical field and facilitates suture line assessment and revision. The shear-thinning and thixotropic properties of RADA16 allow its easy application through a narrow nozzle such as an endoscopic catheter. RADA16 hydrogels can fill tissue voids and do not swell so can be safely used in close proximity to pressure-sensitive tissues and in enclosed non-expandable regions. By definition, the synthetic peptide avoids potential microbiological contamination and immune responses that may occur with animal-, plant-, or mineral-derived topical hemostats. In vitro experiments, animal studies, and recent clinical experiences suggest that RADA16 nanofibrous hydrogels can act as surrogate extracellular matrices that support cellular behavior and interactions essential for wound healing and for tissue regenerative applications. In the future, the unique nature of RADA16 may also allow us to use it as a depot for precisely regulated drug and biopharmaceutical delivery.

Prevention of late complications with coverage agents in endoscopic resection of colorectal lesions: Current landscape in gastrointestinal endoscopy

Endoscopic removal of large (≥ 20 mm) non-pedunculated colorectal lesions (LNPCLs) may result in major adverse events, such as delayed bleeding (DB) and delayed perforation (DP), despite closure of the mucosal defects with clips. Topical application of a coverage agent refers to the creation of a shield with a biocompatible medical device (tissue or hydrogel) with proven bioactive properties. Coverage of the eschar after endoscopic resection provides shielding protection to prevent delayed complications. The aim of the present review was to systematically collect and review the currently available literature regarding the prevention of DB and DP with coverage agents after endoscopic mucosal resection or endoscopic submucosal dissection of LNPCLs.

Feasibility and safety of a new endoscopic synthetic sealant nebulizing device over gastric endoscopic submucosal dissections

Background

Endoscopic Submucosal Dissection (ESD) is the treatment of choice of superficial neoplastic gastrointestinal lesions. Delayed bleedings and perforations are still current clinical concerns. Glubran 2 is a synthetic cyanoacrylate-derived glue nowadays already widely used as an effective tissue adhesive. ENDONEB is a novel device thought for enabling the sealant nebulization over a specific targeted surface during laparotomy, laparoscopy, and thoracotomy. The aim of this single-center preclinical animal trial is to evaluate the feasibility and safety of the same nebulization technique during ESD in the perspective that further clinical studies would demonstrate the efficacy of Glubran 2 in preventing post-ESD adverse events.

Methods

Four live Landrace pigs were enrolled. Two approximately 30-mm-wide gastric ESDs were performed in each pig (experimental ESD and control ESD). About 0.5 mL of Glubran 2 was nebulized on the experimental ESDs. Subjective perception of the feasibility of the Glubran 2 nebulization was reported. Pigs were clinically monitored at follow-up and upper GI endoscopy was performed at 24 and 48 hours, when animals were euthanized to perform a macroscopic and histological analysis of the specimens.

Results

No peri-procedural adverse events were reported. Glubran 2 nebulization over experimental ESDs showed to be technically easy and time-effective. Clinical and endoscopic animal monitoring was negative at follow-up. At 24 hours, the Glubran 2 film was clearly visible on the eschar of the ESDs and signs of initial hydrolysis were discernable at 48 hours. No signs of peritoneal reaction were observed at the macroscopic examination. Equal transmural inflammation was described at the histological examination of both types of ESDs.

Conclusions

Safety and feasibility profiles of Glubran 2 nebulizing ENDONEB device over ESD surfaces were excellent. Further evidences and human trials are needed to investigate its effectiveness in ESDs’ eschars sealing and, thus, in delayed micro-perforations and bleedings prevention and treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08480-4.

A novel self-assembling peptide for hemostasis during endoscopic submucosal dissection: a randomized controlled trial

BACKGROUND

 Endoscopic submucosal dissection (ESD) is associated with a risk of bleeding. Bleeding is usually treated with diathermy, although this does carry a risk of mucosal thermal injury. Purastat is a topical hemostat that may be effective in controlling bleeding during ESD, thereby reducing the use of heat therapy. The aim of this study was to assess the reduction in heat therapy used in the interventional group (Purastat) compared with the control group. The secondary aims were to compare the procedure length, time for hemostasis, delayed bleeding rate, adverse events, and wound healing between the groups.

METHODS

 This was a single-center randomized controlled trial of 101 patients undergoing ESD. Participants were randomized to a control group where diathermy was used to control bleeding or an interventional group where Purastat could be used. Follow-up endoscopy was performed at 4 weeks to assess wound healing.

RESULTS

 There was a significant reduction in the use of heat therapy for intraprocedural hemostasis in the interventional group compared with controls (49.3 % vs. 99.6 %, P < 0.001). There were no significant differences in the procedure length, time for hemostasis, and delayed bleeding rate between the groups. Complete wound healing at 4 weeks was noted in 48.8 % of patients in the interventional group compared with 25.0 % of controls (P = 0.02).

CONCLUSIONS

 This study has demonstrated that Purastat is an effective hemostat that can reduce the need for heat therapy for bleeding during ESD. It may also have a role in improving post-resection wound healing.

First report of a Mexican family with mutation in the CDH1 gene

Background

Germline mutations in E‐cadherin (CDH1) gene are associated with autosomal‐dominantly inherited cancer syndrome characterized by diffuse gastric cancer, lobular breast cancer, and in some families, cleft lip/palate. However, there may be generations in which these neoplasms do not occur at all in a family and later on, one or another carcinoma arises, which makes it difficult for physicians to think about hereditary origin.

Methods

We report the first Mexican family with CDH1 mutation (variant c.377del).

Results

An asymptomatic young woman underwent a search for mutations in susceptibility genes for breast cancer due to the history of this neoplasm in her mother and maternal aunt. A CDH1 mutation was detected. After an endoscopy, a diffuse gastric carcinoma was found. Later on, three generations of this family were studied. The findings are presented.

Conclusion

Medical communities should be aware of the contribution of this gene in the development of hereditary diffuse gastric carcinoma (HDGC) and breast cancer.

Efficacy of a novel self-assembling peptide hemostatic gel as rescue therapy for refractory acute gastrointestinal bleeding

BACKGROUND

Acute gastrointestinal bleeding (AGIB) results in significant morbidity and mortality. Topical hemostatic products have been developed for endoscopic use to help in the management of difficult bleeding. Our aim was to demonstrate the ease of use, safety, and efficacy of PuraStat, a novel hemostat, to control AGIB.

METHODS

We describe 77 patients (41 men) who were treated for acute upper and lower AGIB in a 2-year period. In 50 patients, bleeding occurred as a complication of a previous endoscopic procedure, predominantly endoscopic mucosal resection (EMR) and endoscopic retrograde cholangiopancreatography (ERCP); however, in the other 27 patients, it derived from peptic ulcers, angiodysplasia, cancers, and surgical anastomoses. Bleeding was spurting in 13 of the 77 patients and oozing in 64. PuraStat was used after the failure of at least two conventional hemostatic methods.

RESULTS

A mean of 2.6 conventional hemostatic methods had been attempted prior to the application of PuraStat. PuraStat achieved successful hemostasis in 90.9 % of patients. In 41 patients, once hemostasis was obtained with PuraStat, endoscopists further stabilized hemostasis by using at least one additional method. Recurrence of bleeding was observed in eight patients (10.4 %). In 16 patients with intraprocedural bleeding, it was possible to complete the procedures (14 EMR, 2 ERCP) after PuraStat hemostasis. No adverse events related to PuraStat were recorded.

CONCLUSIONS

PuraStat is feasible, safe, and effective in controlling different types of gastrointestinal hemorrhage after failure of conventional hemostatic methods. Its application also does not hinder continuing endotherapy.

Application of a novel self-assembling peptide to prevent hemorrhage after EMR, a feasibility and safety study

Background

A novel self-assembling peptide (SAP) can be applied to the post-endoscopic mucosal resection (EMR) defect to treat oozing bleedings. It has been suggested to stimulate early healing of damaged vessels. We hypothesized that SAP application could prevent delayed bleeding (DB) after EMR and performed a prospective cohort study to determine feasibility and safety.

Methods

A total of 48 consecutive patients who underwent EMR between June 2018 and August 2019 for large lesions in the esophagus, duodenum (> 1 cm) or colorectum (> 2 cm) were treated with adjuvant SAP application. Duration and ease of SAP application were measured, as well as DB outcome.

Results

The EMR defects of 48 patients were treated with SAP; 17 in the esophagus, 13 in the duodenum and 18 in the colorectum. SAP was easy to apply on the EMR defect with a median duration of 2.0 min. A dose of 3 cc was generally enough to cover a defect between 10 and 50 mm. An exploratory analysis of the prophylactic ability of SAP showed that 15.9% of patients (7/44) treated with SAP still had a DB, mostly in the duodenum (4/11). No adverse events related to gel exposure were reported.

Conclusions

SAP application after EMR was found to be feasible and safe, and did not delay the procedure; however, DB was still relatively common. Future comparative studies are needed to evaluate whether SAP is able to reduce DB after EMR, particularly for lesions with an increased bleeding risk, such as in the duodenum.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07819-7) contains supplementary material, which is available to authorized users.

Valuing innovative endoscopic techniques: prophylactic clip closure after endoscopic resection of large colon polyps

BACKGROUND AND AIMS

Clip closure of the mucosal defect after resecting large (≥20 mm) nonpedunculated colorectal polyps reduces postprocedure bleeding and is cost saving for payers. Clip costs are not reimbursed by payers, posing a major barrier to adoption of this technique in the community. We aimed to determine appropriate clip costs to support broader use of this procedure in practice.

METHODS

We performed budget impact analysis using our recent decision analytic model, comparing prophylactic clip closure with no clip closure on national cost and outcomes data, to determine the maximum feasible clip price while maintaining cost savings in practice. Sensitivity analyses were performed on important clinical factors.

RESULTS

In the original model, the baseline postprocedure bleeding risk was 6.8%, increasing cost of care by $614.11 averaged among all patients undergoing large polyp resection without clip closure. Prophylactic clip closure of only large right-sided polyps reduced postprocedure bleeding risk by 70.7% but resulted in cost saving only if the price of clips was $100 or less. Comparatively, prophylactic clip closure of large left-sided polyps had no clinical benefit and was not cost saving. Clip closure strategies focused only on extra-large polyps (≥40 mm), or patients taking antithrombotics regardless of polyp characteristics, were only minimally cost saving. Cost savings and maximum tolerated clip prices depended on medical comorbidity, which directly influences the costs of care to manage postprocedure bleeding.

CONCLUSIONS

Prophylactic clip closure after endoscopic resection of large colon polyps, particularly those in the right colon segment, is cost saving but requires clip costs less than $100. Translating these findings into practice requires gastroenterology practices to obtain reimbursement from payers for improved clinical outcomes and to align commercial clip prices with this clinical indication.

Use of Purastat, a novel haemostatic matrix based on self-assembling peptides in the prevention of nasopharyngeal adhesion formation

•

Purastat is a novel haemostatic agent used effectively in nasal procedures in the prevention of epistaxis and adhesions.

•

This study describes the use of PuraStat following division of nasopharyngeal stenosis to reduce the risk of restenosis.

•

On last follow-up the patient experienced excellent resolution of symptoms with no evidence of readhesion.

•

The authors propose that PuraStat may be used in other surgical interventions to prevent mucosal adhesion formation.

Introduction

Purastat is a novel haemostatic agent that has recently been used effectively in nasal procedures, specifically in functional endoscopic endonasal surgery in the prevention of post-operative epistaxis while minimising adhesion formation. This study presents a case of successful application of Purastat following division of a nasopharyngeal/palatal stenosis following radiotherapy.

Presentation of case

A 49-year-old male developed severe nasopharyngeal stenosis following concurrent chemoradiotherapy with curative intent a HPV positive base of tongue squamous cell carcinoma. Following treatment, while the patient experienced excellent metabolic response, he began to progressive nasal obstruction which he reported to be significantly affecting his quality of life. Following multidisciplinary team discussion, division of the stenosis was considered appropriate.

Under general anaesthesia, the patient was positioned lying supine with the neck extended. A Boyle-Davis gag with lip and teeth protection was placed and a Y-suction catheter inserted to lift the palate from the posterior pharyngeal wall. Coblation using a PDW wand was used to divide the area of fibrosis bilaterally toward the superior tonsillar pillar until palatopharyngeus musculature was visible. Injection of 4 mg of Dexamethasone with a hypodermic needle was then performed followed by application of 4 ml of topical Purastat onto the raw surfaces after haemostasis was confirmed.

The patient was discharged the same day on simple analgesia and instructions to avoid exertion for two weeks. He attended follow-up in the outpatient department two months later and reported persisting resolution of his nasal obstructive symptoms. No evidence of recurrence or residual adhesion tissue was noted.

Designer Self-Assembling Peptide Hydrogels to Engineer 3D Cell Microenvironments for Cell Constructs Formation and Precise Oncology Remodeling in Ovarian Cancer

Designer self-assembling peptides form the entangled nanofiber networks in hydrogels by ionic-complementary self-assembly. This type of hydrogel has realistic biological and physiochemical properties to serve as biomimetic extracellular matrix (ECM) for biomedical applications. The advantages and benefits are distinct from natural hydrogels and other synthetic or semisynthetic hydrogels. Designer peptides provide diverse alternatives of main building blocks to form various functional nanostructures. The entangled nanofiber networks permit essential compositional complexity and heterogeneity of engineering cell microenvironments in comparison with other hydrogels, which may reconstruct the tumor microenvironments (TMEs) in 3D cell cultures and tissue-specific modeling in vitro. Either ovarian cancer progression or recurrence and relapse are involved in the multifaceted TMEs in addition to mesothelial cells, fibroblasts, endothelial cells, pericytes, immune cells, adipocytes, and the ECM. Based on the progress in common hydrogel products, this work focuses on the diverse designer self-assembling peptide hydrogels for instructive cell constructs in tissue-specific modeling and the precise oncology remodeling for ovarian cancer, which are issued by several research aspects in a 3D context. The advantages and significance of designer peptide hydrogels are discussed, and some common approaches and coming challenges are also addressed in current complex tumor diseases.