title: Postoperative pericardial adhesion prevention using Carbylan-SX in a rabbit model.
abstract: BACKGROUND
  The presence of dense adhesions within the pericardial space complicates reoperative cardiac surgery. Prior attempts to reduce adhesion formation after primary cardiac surgery using medications or biomaterials have had variable success. Carbylan-SX (Carbylan Biosurgery Inc., Palo Alto, CA) is a hyaluronan-based biomaterial, which has been shown to be effective at reducing adhesions in a nonthoracic rat model. This study evaluates whether Carbylan-SX can effectively reduce postoperative adhesions within the pericardial cavity.
  
  
  METHODS
  Thirty-eight New Zealand white rabbits underwent a left lateral thoracotomy. A pericardiotomy was made and epicardial adhesions were induced on the anterior surface of the heart using a Dremel device (Racine, WI). The rabbits were divided into four groups: controls with abrasions only receiving no treatment (n=10), Carbylan-SX films (n=10), Carbylan-SX aerosolized hydrogel (n=10), and Seprafilm (n=8). The pericardial sac and chest were subsequently closed. Rabbits were sacrificed at a mean of 15 days. For histological analysis, each heart was divided into 12 separate 1 mm sections. Computer imaging software was used to measure the adhesion thickness and the mean of 12 random measurements for each animal was recorded and statistical analysis performed.
  
  
  RESULTS
  Histological analysis revealed all treatment groups to be significantly better than the control (2159 mum thickness, P<0.0001) at preventing adhesions. The Carbylan-SX film and Carbylan-SX aerosolized hydrogel both proved to be better at preventing adhesions than Seprafilm (Genzyme Corp., Cambridge, MA) with an average adhesion thickness of 454 and 577 microm, respectively, compared with 1319 microm for Seprafilm (P<0.0001 and P<0.0005, respectively). The Carbylan-SX film and Carbylan-SX aerosolized hydrogel were equally effective at preventing adhesion formation.
  
  
  CONCLUSIONS
  Carbylan-SX film and Carbylan-SX aerosolized crosslinkable hydrogel are equally effective methods of reducing postoperative pericardial adhesions within the pericardial cavity. Both the Carbylan-SX film and aerosolized hydrogel showed a significantly greater reduction in adhesions than Seprafilm. Clinical application of Carbylan-SX could have significant therapeutic implications in the future.
authors.affiliation: Department of Surgery, Division of Cardiothoracic Surgery, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA. rafe.connors@hsc.utah.edu
authors.forename: Rafe C
authors.initials: RC
authors.lastname: Connors
authors.forename: Jeffery J
authors.initials: JJ
authors.lastname: Muir
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Liu
authors.forename: G Russell
authors.initials: GR
authors.lastname: Reiss
authors.forename: Peter C
authors.initials: PC
authors.lastname: Kouretas
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Whitten
authors.forename: Tyler K
authors.initials: TK
authors.lastname: Sorenson
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Prestwich
authors.forename: David A
authors.initials: DA
authors.lastname: Bull
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods*; D004195:Disease Models, Animal; D005780:Gelatin / Q000627:therapeutic use; D006820:Hyaluronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D020100:Hydrogels / Q000627:therapeutic use; D008297:Male; D010496:Pericardium / Q000473:pathology / Q000601:surgery*; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000473:pathology / Q000517:prevention & control*; D011817:Rabbits; D000267:Tissue Adhesions / Q000473:pathology / Q000517:prevention & control
chemical_list: D020100:Hydrogels; C520950:carbylan-SX; C015233:gelatin film; D011092:Polyethylene Glycols; D005780:Gelatin; D006820:Hyaluronic Acid