High-Density Free Fluid on Computed Tomography: a Predictor of Surgical Intervention in Patients with Adhesive Small Bowel Obstruction.
Patients with adhesive small bowel obstruction (ASBO) often develop intraabdominal free fluid (IFF). While IFF is a finding on abdominopelvic computed tomography (CT) associated with the need for surgical intervention, many patients with IFF can be still managed non-operatively. A previous study suggested that a higher red blood cell count of IFF is highly predictive of strangulated ASBO. We hypothesized that radiodensity in IFF (Hounsfield unit (HU)) on CT would predict the need for surgical intervention.



Patients with clinicoradiological evidence of ASBO between January 2009 and December 2013 were identified. In patients with IFF > 3 cm2identified on CT, the HU was measured in the largest pocket of IFF. A sensitivity analysis was performed to determine a high-density HU threshold. The HU of patients who underwent therapeutic laparotomy was compared with those successfully discharged with non-operative management.



A total of 318 patients with ASBO (median age 52 years, 56.0 % male) were identified. Of 111 patients who had IFF on CT, 55.9 % underwent therapeutic laparotomy and 15.3 % required bowel resection. Radiodensity of IFF in the operative group was significantly higher than that in the non-operative group (18.2 vs. 7.0 HU, p < 0.01). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of high-density IFF (>10 HU) to predict the need for surgical intervention were 83.9, 65.3, 75.4, 76.2, and 75.6 %, respectively.



High-density IFF on CT was significantly associated with the need for surgical intervention in patients with ASBO. Prospective study to validate the predictive value of high-density IFF on CT will be warranted.
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA. kazuhide.matsushima@med.usc.edu.
Kazuhide
K
Matsushima
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Kenji
K
Inaba
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Ryan
R
Dollbaum
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Vincent
V
Cheng
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Moazzam
M
Khan
Department of Radiology, University of Southern California, Los Angeles, CA, USA.
Keith
K
Herr
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Aaron
A
Strumwasser
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Sabrina
S
Asturias
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Evren
E
Dilektasli
Division of Acute Care Surgery, Department of Surgery, University of Southern California, Los Angeles, CA, USA.
Demetrios
D
Demetriades
D000328:Adult; D001202:Ascitic Fluid / Q000000981:diagnostic imaging*; D013505:Digestive System Surgical Procedures; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D007421:Intestine, Small / Q000000981:diagnostic imaging / Q000601:surgery*; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000267:Tissue Adhesions / Q000150:complications / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
Computed tomography; High density; Intraabdominal free fluid; Small bowel obstruction