CHAPTER 22 INTERVENTIONAL RADIOLOGY: DIAGNOSTICS AND THERAPEUTICS
Radiology has always been an important component of a Level I trauma center. This relationship has increased over the last two decades such that it is almost impossible to conceive of caring for a trauma patient without the ability to perform trauma imaging. Interventional radiology techniques, including angiography, angioembolization, and stent placement, have evolved from infrequently used adjuncts in the care of trauma patients into pivotal adjuncts in the nonoperative management of solid organ injury and hemorrhage associated with pelvic trauma. Historically, these techniques have only been available in a dedicated angiographic suite that was physically separate from the resuscitation area and operating room. This required that patients were hemodynamically normal so that they could tolerate the transportation to the angiographic suite. In addition, commitment to availability 24 hours a day from angiographic technologists and staff was necessary to ensure that these techniques would be available. This distinction among resuscitation area, operating room, and angiographic suite has been gradually dissolving over the past decade. Many centers have built angiographic suites into or next to their emergency department so that the risk of transportation has been decreased. In addition, the development of better radiolucent operating room tables and portable fluoroscopy machines with digital subtraction capabilities has enabled some interventional radiology techniques to be performed in the operating room. Several institutions have built endovascular suites in their operating room suites for the performance of endovascular techniques by vascular surgeons. This ever increasing fusion of resuscitation area, operating room, and angiographic suite has made interventional radiology techniques available to more trauma patients than ever before.
BLUNT CEREBROVASCULAR INJURY
Several screening triggers have been suggested in the literature including cervical spine fracture, neurologic findings not explained by radiographic findings, Horner’s syndrome, LeFort II or III facial fractures, skull base fractures involving the foramen lacerum, and neck soft tissue injury. A good screening test should be relatively inexpensive, have a low morbidity rate, and a high sensitivity rate. It should find all the true positive results with some false positives and no false negatives. In a comparison of magnetic resonance angiography (MRA), computed tomographic angiography (CTA), and four-vessel cerebral angiography between 2000 and 2002, the sensitivity of MRA and CTA for BCVI was 47%–53%. These rates are too low for a test to be an effective screening modality. Four-vessel cerebral angiography has been identified as the gold standard for the diagnosis of BCVI. However, its cost and major complication rate of 1%–3% in large series make it a less than ideal screening test. The development of the multidetector CT scanner has increased the resolution of the CT scanner. Two recent studies demonstrated that CTA performed on multidetector CT scanners has dramatically improved ability to diagnose these injuries. A head-to-head comparison of CTA with multidetector CT scanners and four-vessel cerebral angiography has yet to be done. As a result, four-vessel cerebral angiography remains the gold standard for diagnosis and screening of these injuries. It will be important to continue to monitor improvements in CTA, MRA, and possibly even ultrasound technologies for less invasive, cheaper, and safer screening modalities for BCVI.