Basic Assessment Principles
Injuries to blood vessels are responsible for degrees of morbidity and mortality out of proportion to their relatively infrequent presence in trauma patients. The rapid and accurate identification and characterization of vascular injuries are of great importance in the early workup of an injured patient because the potential immediate consequences of vascular disruption include rapid blood loss directly from the vessel and reduced downstream perfusion resulting from complete or partial luminal occlusion. These effects produce the clinical consequences of hemorrhage and ischemia, which form the basis of the clinical assessment for vascular injuries. Before the broad and rapid availability of advanced imaging techniques such as computed tomographic angiography (CTA) during the early workup of an injured patient, clinical suspicion based on evidence of hemorrhage or ischemia would prompt surgical exploration or invasive imaging (angiography). In modern trauma care, mandatory diagnostic exploration and angiography have been supplanted by CTA, but clinical findings retain importance in determining initial management steps to prevent further physiologic derangement from ongoing hemorrhage or ischemia.
Vascular Diagnostic Pathway
There are three phases in the definitive diagnosis of vascular injuries: physical examination (Phase I), initial modalities (Phase II), and targeted imaging/exploration (Phase III). A physical examination for clinical signs of major vessel injury is always performed, followed in most cases by the subsequent two phases in order. However, imaging may be abandoned if the presence, location, and nature of a vascular injury are clinically obvious or the patient is hemodynamically unstable and requires an emergent life-saving operation.
A complete physical examination is part of the workup of any trauma patient, and the presence of clinical signs discussed later in this chapter should generate suspicion for the presence of a major vessel injury. The initial physical examination represents Phase I of the general diagnostic pathway for vascular injuries. Once an injury is suspected, a plan to rapidly and definitively identify it and the beginnings of a plan to treat it should be made. In most cases, some initial bedside imaging of the anatomic area in which a vascular injury is suspected is obtained next. This may include plain x-rays (of the chest, pelvis, or extremities), a focused abdominal sonography for trauma (FAST) examination, or a measurement of extremity Doppler pressure indices. These initial modalities constitute Phase II of the diagnostic pathway and provide initial localization of the suspected vascular injury. The results of the initial modalities, along with the patient’s physiologic status and response to initial resuscitation, will determine the priority of the vascular injury and if the use of targeted imaging is appropriate. The goal of targeted imaging (typically CTA) of the suspected injury is to definitively identify, localize, and characterize it so that a formal plan for treatment can be formulated. Targeted imaging or early operative exploration represents Phase III of the vascular injury diagnostic pathway (Fig. 2-1...