title: Endoscopic balloon dilation for obstructive colorectal cancer: a basic study on morphologic and pathologic features associated with perforation.
abstract: BACKGROUND
  The use of endoscopic dilation and a self-expandable stent for colorectal cancer (CRC) presenting with a stricture or obstruction, either prior to surgery or as a palliative measure (an alternative to colostomy), causes perforation with relative high incidence (1%-17%).
  
  
  OBJECTIVE
  To experimentally investigate risk factors associated with perforation in excised CRC specimens.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Ex vivo experiment on freshly excised human colon cancer specimens at an academic hospital.
  
  
  METHODS
  This study involved 47 patients with strictured CRCs of <15 mm in internal diameter as assessed by a preoperative contrast enema.
  
  
  METHODS
  Immediately after surgical resection, a balloon with a diameter of 18 mm was placed in the stricture. The balloon was inflated slowly with hydrostatic pressure over 1 minute and kept at the maximum diameter for 1 minute.
  
  
  METHODS
  Correlations between macroscopic perforation and 20 items, including morphological and histopathological characteristics.
  
  
  RESULTS
  Perforation occurred in 8 of 47 (17.0%) CRC specimens. Four items showed statistically significant (P < .05) correlations with perforation: peritumoral proliferation of collagen fibers (relative area > or =23.9% in the visual field), annularity of the tumor, severe stricture (<7.9 mm), and fewer residual smooth muscle cells in the muscularis propria, reflecting tumor encroachment. The best predictor of perforation was a combination of severe stricture and pronounced peritumoral proliferation of collagen fibers.
  
  
  CONCLUSIONS
  An uncontrolled study with a small number of patients.
  
  
  CONCLUSIONS
  Histopathological and morphological items associated with a decrease in elastic compliance were more important as predictors of perforation than dilation procedure parameters, such as balloon pressure.
authors.affiliation: Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara, Japan. atanaka@is.icc.u-tokai.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Tanaka
authors.forename: Sotaro
authors.initials: S
authors.lastname: Sadahiro
authors.forename: Masanori
authors.initials: M
authors.lastname: Yasuda
authors.forename: Satoru
authors.initials: S
authors.lastname: Shimizu
authors.forename: Yuji
authors.initials: Y
authors.lastname: Maeda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tokunaga
authors.forename: Kyoji
authors.initials: K
authors.lastname: Ogoshi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002404:Catheterization / Q000379:methods*; D003094:Collagen / Q000378:metabolism; D003106:Colon / Q000473:pathology; D003108:Colonic Diseases / Q000473:pathology* / Q000628:therapy*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D003187:Compliance; D003238:Connective Tissue / Q000473:pathology; D004548:Elasticity; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000473:pathology* / Q000628:therapy*; D007416:Intestinal Perforation / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000473:pathology; D009361:Neoplasm Invasiveness; D012002:Rectal Diseases / Q000473:pathology* / Q000628:therapy*; D012307:Risk Factors; D015607:Stents
chemical_list: D003094:Collagen