Role of multidetector-row CT in assessing the source of arterial haemorrhage in patients with pelvic vascular trauma. Comparison with angiography.

PURPOSE: We investigated the role of multidetector-row computed tomography (MDCT) in identifying active bleeding and its source in polytrauma patients with pelvic vascular injuries with or without associated fractures of the pelvis.
MATERIALS AND METHODS: From January 2003 to December 2007, 28 patients (19 men and nine women, age range 16-80 years) with acute symptoms from blunt pelvic trauma and a drop in haematocrit underwent MDCT and angiography. Conventional radiography of the pelvis was performed in all patients at the time of admission to the emergency department. MDCT was performed with a four-row unit in 15 patients and a 16-row unit in the remaining 13 patients. The study included whole-body CT to identify craniocerebral, vertebral, thoracic, abdominal and pelvic injuries. CT was performed before and after rapid infusion (4-5 ml/s) of intravenous contrast material (120 ml) using a power injector. A triphasic contrast-enhanced study was performed in all patients. MDCT images were transferred to a workstation to assess pelvic fracture, site of haematoma and active extravasation of contrast material, visibility of possible vascular injuries and associated traumatic lesions. At angiography, an abdominal and pelvic aortogram was obtained in all cases before selective catheterisation of the internal iliac arteries and superselective catheterisation of their branches for embolisation purposes. Results related to identifying the source of bleeding at MDCT were compared with sites of bleeding or vascular injury identified by selective pelvic angiography. The sensitivity and positive predictive value (PPV) of MDCT were determined.
RESULTS: MDCT allowed us to identify pelvic bleeding in 21/28 patients (75%), with most cases being detected in the delayed contrast-enhanced phase (13/21 cases, 61.9%). Injured arteries were identified on MDCT in 12/21 cases (57%): the obturator artery (n=9), internal iliac artery (n=6), internal pudendal artery (n=6) and superior gluteal artery (n=5) were most frequently injured. In 8/21 patients (28.6%), more than one artery was injured. Among the 12 patients in whom MDCT showed the presence of pelvic haemorrhage, there was agreement between MDCT and angiography in ten cases. Angiography confirmed the site of bleeding detected on MDCT and identified a second arterial haemorrhage in one patient. There was no agreement between MDCT and angiography in the last patient. MDCT showed a sensitivity of 42.85% and a PPV of 100% in identifying the injured arteries.
CONCLUSIONS: Arterial haemorrhage is one of the most serious problems associated with pelvic fracture, and it remains the leading cause of death attributable to such fractures. MDCT provides diagnostic information regarding the presence of small pelvic fractures and, thanks to the contrast-enhanced angiographic technique, it is capable of identifying pelvic bleeding, with the demonstration in some cases of it source. The presence of contrast material extravasation is an indicator of injury to a specific artery passing through the region of the pelvis where the extravasation is noted on MDCT. Urgent angiography and subsequent transcatheter embolisation are the most effective methods for controlling ongoing arterial bleeding in pelvic injuries.