Abstract
Oxidized regenerated cellulose (ORC) is a commonly used surgical hemostatic agent. When retained at the surgical site, it is frequently misdiagnosed on postoperative computed tomography (CT) images as an abscess or a recurrent tumor. Oxidized nonregenerated cellulose (ONC) is a new, more effective version of ORC. It is more effective because of its unorganized fiber structure and greater material density, which may also alter its appearance on CT images relative to ORC. This image report compares the CT characteristics of ONC and ORC. A rabbit's bilateral femoral arteries were punctured to model peripheral vascular surgery. ORC was used to treat 1 of the femoral artery punctures and ONC to treat the contralateral puncture. Noncontrast CT imaging was performed immediately following surgery (day 0) and on postoperative day 14. On day 0, both ORC and ONC were isoattenuating relative to muscle and hyperattenuating to fat, although ONC appears more homogenous. On day 14, neither ORC nor ONC was clearly identifiable. Thus, postoperative retention of ONC can obscure immediate postoperative CT interpretation and, similar to ORC, lead to an erroneous diagnosis of an abscess. By day 14, ONC retention may not obscure CT interpretation. In noncontrast CT imaging, ONC appears more homogeneous than ORC, but is otherwise indistinguishable. The greater homogeneity of ONC may be caused by the unorganized fiber structure or greater material density. Intraoperative use of ONC should be clinically investigated before radiographically diagnosing a postoperative abscess or recurrent tumor.