Novel temperature-responsive, biodegradable and injectable collagen sol for the endoscopic closure of colonic perforation holes: Animal study (with videos)

A review of hydrogels used in endoscopic submucosal dissection for intraoperative submucosal cushions and postoperative management

Endoscopic submucosal dissection (ESD) has been clinically proved to have prominent advantages in the treatment of early gastrointestinal cancers over traditional surgery, including less trauma, fewer complications, a quicker recovery and lower costs. During the procedure of ESD, appropriate and multifunctional submucosal injected materials (SIMs) as submucosal cushions play an important role, however, even with many advances in design strategies of SIMs over the past decades, the performance of the submucosal cushions with postoperative management function seems to be still unsatisfactory. In this review, we gave a brief historical recount about the clinical development of SIMs, then some common applications of hydrogels used as SIMs in ESD were summarized, while an account of the universal challenges during ESD procedure was also outlined. Going one step further, some cutting-edge functional strategies of hydrogels for novel applications in ESD were exhibited. Finally, we concluded the advantages of hydrogels as SIMs for ESD as well as the treatment dilemma clinicians faced when it comes to deeply infiltrated lesions, some technical perspectives about linking the clinical demand with commercial supply were also proposed. Encompassing the basic elements of SIMs used in ESD surgery and the corresponding postoperative management requirements, this review could be a good reference for relevant practitioners in expanding the research horizon and improving the well-being index of patients.

Potential of temperature-response collagen-genipin sol as a novel submucosal injection agent for endoscopic resection: Acute and chronic phase study using living animals

OBJECTIVES

We proposed a novel temperature-response collagen sol as a submucosal injection agent for endoscopic resection (ER) using pepsin-solubilized collagen (PSC) and genipin (Ge) in a prior study. This study aimed to evaluate the usefulness and safety of the sol (PSC/Ge) in acute and chronic phase experiments using living animals.

METHODS

In experiment 1, we performed endoscopic submucosal dissection (ESD) for six pigs using normal saline (NS), sodium hyaluronate (SH), and PSC/Ge. We compared the required amount of each agent per unit area and procedure time. In experiment 2, we created artificial ulcers with endoscopic mucosal resection (EMR) for five pigs using NS and PSC sol. We compared the artificial ulcer residual rate at 7 and 14 days after EMR, and the scarring rate at 14 days after EMR.

RESULTS

The required amount of agents per unit area for PSC/Ge (0.8 ± 0.8 mL/cm² ) and SH (1.1 ± 0.8 mL/cm² ) were significantly smaller than that for NS (1.8 ± 0.7 mL/cm² ). The total procedure time did not have a statistical difference. The artificial ulcer residual rates were 47.3 ± 0.7% for NS and 40.3 ± 0.7% for PSC/Ge on day 7 (P = 0.51), and 15.0 ± 0.1% for NS and 10.2 ± 0.1% for PSC/Ge sol on day 14 (P = 0.35). The scarring rate on day 14 was 10% for NS and 20% for PSC/Ge.

CONCLUSION

We demonstrated the feasibility of a novel temperature-response collagen gel as a submucosal injection agent for ER in the acute and chronic phase animal experiment.

Closure of gastric perforations during endoluminal resection using a novel biodegradable collagen sol: A feasibility survival study on porcine model (with video)

OBJECTIVE

A prior study using porcine colon demonstrated the feasibility of a novel injectable, temperature?responsive, and biodegradable collagen sol (ICS) that transforms from a liquid to a gel state in response to body temperature for endoscopic closure of perforation during endoscopic resection (ER). This study aims to report the acute and survival outcomes of ICS for gastric perforations during ER.

METHODS

In two experiments using nine live pigs under general anesthesia, four and six perforations (3-5\xA0mm) were created using an electrosurgical knife in acute and survival experiments, respectively. ICS was delivered to the perforations using an endoscopic catheter. In Experiment 1, a leak test and histopathology were performed on all explanted stomachs after euthanization. In Experiment 2, perforation sites were assessed by gastroscopy and histopathology 7, 14 and 28\xA0days post?

RESULTS

In Experiment 1, gastroscopy confirmed complete closure of the perforations with ICS and no evidence of leak. Subsequent histopathology revealed a fixation of collagen gel (CG) as a sealant agent at the perforation sites. There were no adverse effects related with ESD or the use of ICS. In Experiment 2, histopathology revealed a fixation of CG as a sealant agent, replacement with granulation tissue and no CG; and fibrotic tissue at 7, 14 and 28\xA0days, respectively.

CONCLUSIONS

This study presents a novel method using ICS, demonstrating promising efficacy and safety profile for endoscopic closure of perforations during ER. Further studies are necessary before translating to clinical use.