title: MDCT of retractor-related hepatic injury following laparoscopic surgery: appearances, incidence, and follow-up.
abstract: OBJECTIVE
  To investigate the postoperative computed tomography (CT) features resulting from the use of Nathanson retractors during laparoscopic upper gastro-intestinal surgery.
  
  
  METHODS
  A 3-year retrospective study of 176 patients who had undergone laparoscopic upper gastro-intestinal surgery for bariatric or malignant disease was performed. Postoperative CT images [divided into early (≤ 30 days) and late (>30 days)] were assessed by a consultant radiologist and liver abnormalities recorded.
  
  
  RESULTS
  The features of a retractor injury were a hypodense lesion, abutting the liver edge, usually triangular or linear in shape. Late postoperative features included focal subcapsular retraction and associated liver atrophy. Sixty-eight percent (52/77) of patients undergoing surgery for malignancy underwent postoperative CT, compared with 11% (11/99) of those undergoing bariatric surgery. Patients with malignancy were more likely to have retraction-related liver abnormalities (14/52, 27%) at postoperative CT than those in the bariatric group (2/11, 18%).
  
  
  CONCLUSIONS
  Retractor-related liver injuries at MDCT are common following laparoscopic upper gastro-intestinal surgery. Recognition of the characteristic triad of features, a hypodense lesion abutting the liver edge with a triangular or linear shape, should allow confident diagnosis. CT follow-up reveals that over time these lesions may disappear, remain unchanged, or result in a focal subcapsular scar with associated atrophy.
authors.affiliation: Department of Radiology, Derriford Hospital, Plymouth, Devon, UK. Electronic address: katharine.orr@nhs.net.
authors.forename: K E
authors.initials: KE
authors.lastname: Orr
authors.affiliation: Department of Radiology, Derriford Hospital, Plymouth, Devon, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050110:Bariatric Surgery / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000601:surgery; D006801:Humans; D007431:Intraoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology; D010535:Laparoscopy / Q000009:adverse effects*; D008099:Liver / Q000000981:diagnostic imaging / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D012189:Retrospective Studies; D055815:Young Adult