Over the past five decades of experience in the management of extremtty vascular trauma, a number of factors have been identified that directly influence outcome. These include the time between injury and treatment, mechanism, anatomic location, associated injuries, age and comorbidity, and clinical presentation. A knowledge of these prognostic factors is essential for the appropriate evaluation and treatment of these patients.
The time from injury to treatment is perhaps the most critical determinant of salvage of both life and limb following extremity vascular injury, as it is for all forms of trauma. This is explained by the time-dependent nature of the two major consequences of vascular injury, hemorrhage and ischemia. A linear correlation between delay in treatment of arterial injuries and limb loss was shown in World War II.’ This association has become even stronger in both experimental and clinical studies that involve prompt repair and restoration of blood flow following acute arterial injury. In 1949, Miller and Welch” showed increasing rates of limb loss with increasing time delay of reperfusion of canine hind limbs after femoral artery ligation. This relation also was
demonstrated in wounded soldiers in subsequent military conflicts in Afghanistan 8 and Lebanon,” where amputation
rates rose from 22 and 3%, respectively, among injuries revascularized within 6 to 12 h, to as high as 93% when revascularization was delayed more than 12 h. Several civilian clinical series have since confirmed this close correlation of limb loss with delay in revascularization, especially when extremity arterial injury is complicated by associated injuries to vein, soft tissue, and bone. Even salvaged limbs following a delay in treatment are subject to functional disability from damage to nerve and muscle, as well as the development of potentially dangerous vascular complications such as false aneurysms arid AVFs (Fig. 43—5). These latter lesions are more difficult to repair than acute vascular injuries and have a greater perioperative morbidity and mortality in some series.” These results have established the critical time interval for restoration of limb perfusion and optimal limb salvage to be at most 6 to 8 h following extremity vascular trauma. The degree of ischemia and extent of collateral circulation affects tissue tolerance of delay. Therefore, prompt diagnosis and treatment of vascular injuries must be a major goal of management of all extremity trauma." ’ The low incidence of false aneurysms and AVFs in large series of vascular injuries (see Table 43--4) demonstrates how’well this principle has been teamed.
Blunt mechanisms of injury involve a wider application of force, with greater damage to extremity vessels and surrounding structures than is imparted by penetrating trauma. Blunt vascular injuries ai‘e associated with a more difficult diagnosis, ‘and higher rates of amputation and severe dysfunction than are simple penetrating vascular injuries, which are typica1ly clean, isolated, and more easily diagnosed and re-
- paired." ""' 5 56 Among penetrating injuries, stabs impart the least destructive force and are associated with a
small and discrete area of injury 5 As discussed earlier, high-
velocity gunshot and shotgun wounds create a level of daiiiage similar to blunt trauma, in terms of the complexity and extent of the damage, the difficulty of diagnosis and treatment, and the higher rate of limb loss 5 This increased
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