title: The "O" sign, a simple and helpful tool in the diagnosis of laparoscopic adjustable gastric band slippage.
abstract: OBJECTIVE
  The purpose of this article is to describe a sign on radiography for gastric band slippage, a complication of adjustable gastric banding surgery, and to emphasize the importance of this finding to radiologists and clinicians.
  
  
  METHODS
  We reviewed the radiologic findings in 55 consecutive patients who underwent laparoscopic gastric banding. Between January 2007 and September 2008, gastric band slippage was diagnosed in four patients at our institution. All patients underwent an upper gastrointestinal examination at the time of presentation. On the basis of either radiographic findings or clinical presentation, all patients underwent exploratory surgery.
  
  
  RESULTS
  In all four patients with surgically proven gastric band slippage, the initial abdominal radiograph showed an O-shaped configuration of the gastric band, which we have termed the "O" sign. Baseline upper gastrointestinal examinations were available for comparison in all patients. In each case, the O-shaped configuration of the band was a change from its rectangular appearance when in the proper position.
  
  
  CONCLUSIONS
  As laparoscopic adjustable gastric banding is increasingly used, more patients will present to the emergency department with complications of the procedure, particularly complications from band slippage. Because the consequences of slippage may require acute surgical intervention, it is imperative that the radiologist is familiar with the surgical technique to correctly position the band and the appearances of a gastric band when correctly and incorrectly positioned. Identification of the O sign on radiography can potentially aid the radiologist, surgeon, or emergency department physician in the early detection of gastric band slippage and appropriate patient triage.
authors.affiliation: Department of Radiology, Boston Medical Center, MA, USA. sabrinapieroni@gmail.com <sabrinapieroni@gmail.com>
authors.forename: Sabrina
authors.initials: S
authors.lastname: Pieroni
authors.forename: Eric A
authors.initials: EA
authors.lastname: Sommer
authors.forename: Rania
authors.initials: R
authors.lastname: Hito
authors.forename: Miguel
authors.initials: M
authors.lastname: Burch
authors.forename: Jaroslaw N
authors.initials: JN
authors.lastname: Tkacz
mesh_terms: D000328:Adult; D003287:Contrast Media; D004867:Equipment Design; D005260:Female; D015391:Gastroplasty / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011859:Radiography
chemical_list: D003287:Contrast Media