In the management of patients with traumatic injuries, the primary role for diagnostic radiology is to identify patients who may be at risk of death because of visceral bleeding in the acute period. Days, weeks, months, or even years after successful
In the management of patients with traumatic injuries, the primary role for diagnostic radiology is to identify patients who may be at risk of death because of visceral bleeding in the acute period. Days, weeks, months, or even years after successful conservative treatment, some trauma patients develop delayed complications as a result of partial- or full-thickness tears of the vessel walls or complete transection.
These complications, as well as acute or delayed injuries to large vessels, can be treated effectively with endovascular techniques, according to speakers at the ECR on Friday morning.
Although most trauma patients die at the accident site as a result of central nervous system compromise and disruption of large vessels, a significant number die from abdominal hemorrhage during the second peak of acute mortality a few hours after injury. To be sure they do not "diagnose patients to death," radiologists should confine x-rays to a minimum by focusing radiographic studies on the lateral cervical spine and anteroposterior chest and pelvis, said Prof. Dr. Robert Dondelinger from the University of Liège, Belgium.
Rather than waste time grading injury, radiologists should place patients in one of two broad categories on the basis of CT findings. Patients with probable hemorrhage are hemodynamically stable and do not necessarily have indications of hemorrhage in the hemoperitoneum, the presence of a sentinel clot, or a small "blush." Patients who have ongoing bleeding often exhibit progressive dilution of contrast material from the source of bleeding into the hemoperitoneum or spread of contrast beyond the parenchymal capsule and inside interstitial tissue, Dondelinger said.
"The negative effects of imaging on trauma patients in particular involve time loss in diagnosis of non-life-threatening conditions by improper imaging sequences and prolonged imaging in hemodynamically decompensated patients," he said.
Most patients who develop delayed complications of treatment for traumatic injury can be managed without surgery in the radiology department, and it is the nature of vascular injury that determines the mode of endovascular therapy, said Dr. James E. Jackson from the Hammersmith Hospital in London.
When a vascular injury involves a vital vessel, the goal of treatment is to preserve patency, primarily by the placement of covered stents. Packing of the aneurysm sac may be considered if it is the only option, Jackson said. When a pseudoaneurysm or arteriovenous fistula involves a non-vital vessel, radiologists must look for a "back door" collateral supply of blood before embolization.
A stent successfully occluded and caused complete thrombosis of a pseudoaneurysm in a patient who had a partial tear of the thoracic aorta six months after sustaining severe traumatic chest and abdominal injuries. And because a full-thickness tear of the main pulmonary artery generally is not readily managed with a covered stent, Jackson packed a pseudoaneurysm with coils in a patient who had massive hemoptysis a year after postoperative hemorrhage following partial hepatectomy. When the clot retracted and lysed, the coils fell into the cavity and recanalization occurred. Four months later, the patient was retreated endovascularly, with glue placed at the origin of the pseudoaneurysm.
For a patient with an arteriovenous fistula four years after surgical correction of macrognathia, Jackson needed to work out the anatomy before attempting embolization to determine whether collateral circulation was feeding the fistula distally. When the tear in the vessel continued to fill after it was occluded proximally, Jackson moved more distally and worked back toward the site of the fistula.
Although ultrasound is the imaging modality of choice for assessing traumatic and nontraumatic injuries to blood vessels in emergencies, contrast-enhanced CT, particularly with multidetector machines, yields the most information about central vascular injuries, said Prof. Dr. Johannes Lammer from the Medical University of Vienna.
Treatment of vascular injuries with endovascular techniques, most commonly with stents covered by a plastic membrane, solves vascular problems before surgery is performed to treat other traumatic injuries.
"Interventional radiology techniques can treat the majority of arterial injuries and should be offered in state-of-the-art centers," Lammer said.