Aberrant Obturator Artery Is a Common Arterial Variant That May Be a Source of Unidentified Hemorrhage in Pelvic Fracture Patients

Abstract

Similar to all pelvic arteries, the aberrant obturator artery (AOA) and its branches are at risk for injury when the pelvic ring is fractured; however, because of its unique origin, bleeding from this artery may be unrecognized and, thus, treatment ineffective. The purpose of this study was to describe the incidence of the AOA using angiography and determine the sensitivity of 64-slice computed tomography angiography (CTA) at identifying the AOA. Imaging from patients undergoing pelvic angiography, for any reason, during 2009 was retrospectively reviewed to determine the incidence of the AOA. The angiographically determined arterial anatomy was the compared with CTA findings. Pelvic angiography, performed in 174 patients, identified the AOA in 60.0% of males, 52.3% of females, 55.1% of all patients, and 38.4% of hemipelvises. The sensitivity/specificity of CTA at identifying the AOA is 90.0%/100% and 63.6%/92.3% in nonpelvic fracture and pelvic fracture patients, respectively; the sensitivity difference being significant (p=0.0351). Three of the 13 (23.1%) AOA identified in pelvic fracture patients demonstrated extravasation when the inferior epigastric artery was cannulated; however, flush angiography failed to demonstrate the extravasation. The AOA is a common arterial variant occurring in more than half of the population and, if present in pelvic fracture patients, commonly injured. Although CTA is effective at identifying the AOA in nonpelvic trauma patients, it is not as effective in pelvic fracture patients. Failure to consider this arterial variant may result in untreated arterial bleeding with the attendant consequences.