title: Efficacy of colonic submucosal saline solution injection for the reduction of iatrogenic thermal injury.
abstract: BACKGROUND
  Submucosal saline solution injection may limit the depth of thermal injury to the gut wall by acting as a heat-sink and by increasing the distance between burn and serosa. The aim of this study was to determine the effect of submucosal saline solution injection on depth of colonic thermal injury produced by commonly used endoscopic thermal modalities.
  
  
  METHODS
  Longitudinal colotomy incisions were made on the antimesenteric colonic border of anesthetized swine. Lesions were made by using a bipolar device (20 W, 2 seconds), heat probe (30 J); monopolar contact with hot biopsy forceps (20 W, 2 seconds), and monopolar noncontact with argon plasma coagulation (45 W, 3 seconds). Ten or more lesions were created with each device. Lesions were made with or without prior submucosal injection of 2 mL of normal saline solution. After 24 hours the lesions were excised for histologic analysis. Injury was assessed in relation to the severity of damage to the deep (longitudinal) muscle layer.
  
  
  RESULTS
  The proportions of control lesions (without submucosal saline solution injection) in which deep injury was evident were as follows: argon plasma coagulation, 86%; hot biopsy forceps, 64%; heat probe, 50%; bipolar device, 18%. Submucosal saline solution injection significantly reduced the proportions of lesions with deep injury for argon plasma coagulation (p = 0.009) and heat probe (p = 0.03), but not hot biopsy forceps or bipolar device (argon plasma coagulation, 86% to 21%; heat probe, 50% to 0%; hot biopsy forceps, 64% to 50%; bipolar device, 18% to 9%).
  
  
  CONCLUSIONS
  At equivalent energy outputs, the bipolar device results in less deep injury than the monopolar or heat probe. Submucosal saline solution injection reduced injury to the muscularis propria caused by both heat probe and argon plasma coagulation, but not hot biopsy forceps. Despite submucosal saline solution injection, caution should be exercised when using prolonged monopolar cautery.
authors.affiliation: Division of Gastroenterology and Hepatology, Developmental Endoscopy Unit, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Norton
authors.forename: Linan
authors.initials: L
authors.lastname: Wang
authors.forename: Susan A
authors.initials: SA
authors.lastname: Levine
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Burgart
authors.forename: Erik K
authors.initials: EK
authors.lastname: Hofmeister
authors.forename: Ashwin
authors.initials: A
authors.lastname: Rumalla
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gostout
authors.forename: Bret T
authors.initials: BT
authors.lastname: Petersen
mesh_terms: D000818:Animals; D001706:Biopsy / Q000009:adverse effects; D002056:Burns / Q000517:prevention & control*; D002425:Cautery / Q000009:adverse effects; D003106:Colon / Q000293:injuries*; D016145:Endoscopy, Digestive System / Q000009:adverse effects*; D005260:Female; D007049:Iatrogenic Disease / Q000517:prevention & control*; D007267:Injections; D017075:Laser Coagulation / Q000009:adverse effects; D012965:Sodium Chloride / Q000008:administration & dosage; D013552:Swine
chemical_list: D012965:Sodium Chloride