title: CT appearances following laparoscopic partial nephrectomy for renal cell carcinoma using a rolled cellulose bolster.
abstract: OBJECTIVE
  To describe the evolving computed tomography (CT) appearances of a cellulose surgical bolster used as a hemostatic agent in patients who undergo laparoscopic partial nephrectomy for renal cell carcinoma.
  
  
  METHODS
  We retrospectively reviewed the follow-up CT studies of 33 patients with stage T1N0M0 renal carcinoma who underwent laparoscopic partial nephrectomy using a rolled, oxidized, regenerated cellulose sheet sutured in place as a bolster in the parenchymal defect. Thirteen patients undergoing laparoscopic partial nephrectomy without the use of a bolster were also evaluated to differentiate imaging features.
  
  
  RESULTS
  The bolster-related masses were significantly larger than those seen in the non-bolster patients. There was a decrease in size of the post-operative bolster-related mass with time. The bolster shape evolved with time, initially appearing oval, and becoming irregular with decreasing size. Equivocal increase in attenuation of 10-20 HU was seen in 6 patients. Increase in attenuation of greater than 20 HU was seen in 3 patients. There was no evidence of tumor recurrence in any of the patients. Invagination of fat was seen in two bolster-related masses at 18 months or greater.
  
  
  CONCLUSIONS
  Cellulose bolster has a variable appearance on follow-up CT exams. Evolutionary features include reduction in bolster size and shape with time leading finally to non-visualization. Bolster enhancement can mimic abscesses and tumor recurrence.
authors.affiliation: Departments of Radiology, University of Michigan Hospitals, Ann Arbor, MI 48109, USA.
authors.forename: Deepa
authors.initials: D
authors.lastname: Pai
authors.forename: Jonathon M
authors.initials: JM
authors.lastname: Willatt
authors.forename: Melvyn
authors.initials: M
authors.lastname: Korobkin
authors.forename: Richard H
authors.initials: RH
authors.lastname: Cohan
authors.forename: James H
authors.initials: JH
authors.lastname: Ellis
authors.forename: Isaac R
authors.initials: IR
authors.lastname: Francis
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Wolf
authors.forename: Matthew
authors.initials: M
authors.lastname: Schipper
mesh_terms: D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D002482:Cellulose / Q000627:therapeutic use*; D006488:Hemostasis, Surgical / Q000295:instrumentation*; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D010535:Laparoscopy; D009392:Nephrectomy / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D002482:Cellulose