title: Compression of the superior mesenteric vein-a sign of acute internal herniation in patients with antecolic laparoscopic Roux-en-Y gastric bypass.
abstract: OBJECTIVE
  To investigate whether compression of the superior mesenteric vein (SMV) on computed tomography (CT) can serve as a valid sign of internal herniation (IH) in patients with antecolic laparoscopic Roux-en-Y gastric bypass (LRYGBP).
  
  
  METHODS
  With institutional review board approval, we performed a retrospective analysis of 41 patients with antecolic LRYGBP referred for acute CT of the abdomen with suspicion of IH or another cause of acute abdomen. CT scans were randomly reviewed for signs of IH by two radiologists in a blinded manner, and the findings were correlated with the results of the patients' bariatric workup. Sensitivity, specificity, and inter-observer agreement were calculated for each sign.
  
  
  RESULTS
  Five patients were classified as having intermittent IH and were excluded. Eighteen patients were found to have IH at laparoscopy and served as the study group; 18 patients served as the control group. SMV compression had the best sensitivity (67 % for both reviewers) and inter-observer agreement (kappa = 0.82) of all investigated signs. The swirl sign showed a lower sensitivity (39 and 50 % respectively) and kappa (0.37).
  
  
  CONCLUSIONS
  SMV compression is a reliable sign of IH in patients with antecolic LRYGBP.
  
  
  CONCLUSIONS
  • CT can help detect internal herniation after laparoscopic Roux-en-Y gastric bypass. • Compression of the superior mesenteric vein is a sign of internal herniation. • This sign has a high inter-observer-agreement. • A diagnosis of internal herniation can be made with greater confidence.
authors: Department of Radiology, Køge Sygehus, Lykkebækvej 1, 4600, Køge, Denmark. jefm@regionsjaelland.dk.
authors: Jens
authors: J
authors: Maier
authors: Department of Radiology, Køge Sygehus, Lykkebækvej 1, 4600, Køge, Denmark.
authors: Amaya
authors: A
authors: Herrasti Gallego
authors: Department of Abdominal Surgery, Holbæk Sygehus, Smedelundsgade 60, 4300, Holbæk, Denmark.
authors: Andrea K
authors: AK
authors: Floyd
mesh_terms: D000006:Abdomen, Acute / Q000209:etiology; D034841:Abdominal Cavity; D000208:Acute Disease; D000328:Adult; D000368:Aged; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D046449:Hernia, Abdominal / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008642:Mesenteric Veins / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000000981:diagnostic imaging / Q000209:etiology*; D009767:Obesity, Morbid / Q000601:surgery; D015588:Observer Variation; D010808:Physical Examination; D011312:Pressure; D011897:Random Allocation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
keywords: Gastric bypass, Roux-en-Y; Hernia, abdominal; Multidetector computed tomography; Observer variation; Sensitivity and specificity