title: Thermo-sensitive isopentane aerification for mucosal lift during endoscopic resection in animal models (with video).
abstract: OBJECTIVE
  Mucosal lift is critical for successful endoscopic treatment. Normal saline (NS) solution is widely used as the submucosal filler, but its short persistency restricts clinical endoscopic submucosal dissection (ESD). In this study, thermo-sensitive isopentane was introduced for submucosal injection. With a boiling point at 27.8°C, liquid isopentane can be easily applied, and gasification inflation can provide great support for submucosal lifting at body temperature. The feasibility and efficiency of isopentane were evaluated in this study.
  
  
  METHODS
  Porcine stomachs were used for in vitro evaluation. A 37°C water bath was used to mimic body temperature. Compared with NS, isopentane was studied for its lifting performance, including injection dosage, persistence of lifting strength, and efficacy for assisting submucosal dissection. The changes in submucosal tissue were also compared. For in vivo evaluation, rats were used to further compare the differences between isopentane and NS, including lifting efficacy, pathologic effect, and safety.
  
  
  RESULTS
  Compared with NS, the maximum lifting height was achieved with less isopentane (2% NS volume). Longer persistency and faster operation for submucosal dissection were also recorded for isopentane during the in vitro study. Aerification resulted in vacuolization of submucosal connective tissue, which facilitates EMR and postoperative recovery. The same results were confirmed in the rat model. With the same dosage, isopentane produced better mucosal elevation and larger range than NS. According to the histologic examination, no tissue injury was observed with isopentane application.
  
  
  CONCLUSIONS
  As a submucosal injection agent, the feasibility, efficacy, and safety of isopentane has been demonstrated. Thermo-sensitive aerification may be a promising approach to facilitate ESD.
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Liu
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Zhining
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Digestive Endoscopy Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
mesh_terms: D000818:Animals; D000069916:Endoscopic Mucosal Resection / Q000379:methods*; D005240:Feasibility Studies; D005753:Gastric Mucosa / Q000601:surgery*; D007267:Injections; D010420:Pentanes / Q000008:administration & dosage* / Q000737:chemistry; D051381:Rats; D012965:Sodium Chloride / Q000008:administration & dosage; D013552:Swine; D013696:Temperature; D014835:Volatilization
chemical_list: D010420:Pentanes; D012965:Sodium Chloride; C067038:isopentane