Practice Essentials
Patients with extremity vascular trauma present daily in emergency departments (EDs) and trauma centers worldwide. [1, 2] Although much of the current state-of-the-art information is the result of wartime observations, the incidence of civilian extremity vascular trauma is significant. A basic understanding of both blunt and penetrating injuries to the extremities and the resultant vascular abnormalities that occur with these injuries helps minimize mortality and morbidity in these patients.
Civilian extremity vascular injury, as with the wartime experience, is most prevalent in cases of penetrating trauma [3] ; however, in contrast to the military experience, penetrating trauma in the civilian setting is usually due to knife wounds or low-velocity handgun injuries. [4] Fortunately, high-velocity assault weapon injuries and explosive injuries are less common in the United States.
In many parts of the world, regional conflicts in which antipersonnel mines are used has given rise to a large population of children and civilian adults with extremity vascular and soft-tissue injuries resulting in amputations. Civilian clinicians expecting to render aid and services in these areas can refer to references such as Husum and colleagues' War Surgery Field Manual to augment their knowledge of civilian wartime injuries. [5]
Vascular injuries can be classified clinically into hard signs and soft signs of injury on the basis of examination (see Presentation). Both hard and soft signs help direct the clinician to the best diagnostic and treatment options for an individual patient.
Medical therapy alone is rarely an option in penetrating or blunt trauma to the extremity vasculature when hard signs of injury are present. Patients who are asymptomatic or who have only soft signs can often be observed, but such observation is best performed by a surgeon who is prepared to operate if changing circumstances require it. The observation must be performed with the understanding that if the examination findings change or if hard signs develop, surgical intervention is necessary. Surgical intervention can be as minor as operative visualization of normal vascular anatomy for diagnostic purposes or as extensive as reconstruction and replacement of entire segments of injured vessels.
Improved Emergency Medical Services (EMS) systems, faster transport times, availability of interventional radiologic techniques, improved surgical technique, and newer vascular conduits may further reduce the morbidity and mortality of extremity vascular injury. The future of limiting the morbidity and mortality of these injuries probably lies with advances in other areas, such as motor vehicle safety, worldwide control and cleanup of antipersonnel mines, and injury prevention programs.
Anatomy
A thorough knowledge of basic medical-school anatomy of the extremities is essential in the evaluation and management of extremity vascular injuries. Although it is often possible to visualize an arterial injury directly through an open wound, obtaining proximal and distal control for vascular reconstruction requires intimate knowledge of vascular, muscular, and bony anatomy to allow rapid access to the arterial tree proximally and distally while incision length and surgical tissue dissection are minimized.
Frequently, especially in cases of blunt trauma and arterial trauma with ongoing hemorrhage, the normal tissue planes are destroyed, and the smooth muscle in both the artery and the vein cause retraction of the vessels into the depths of the wound. Operative identification of arterial and venous injury as a prelude to repair often requires proximal and distal control of the artery or vein, which may require extending the wound in both directions or making counterincisions.
Temporary vascular control can be achieved by simply applying pressure to the vessel proximal to the injury (eg, femoral pressure in a lower-extremity wound). The prevailing view has generally been that the application of tourniquets, while helpful in the operating room, should be limited to patients at risk for exsanguination in the prehospital and field environments who are not responsive to direct pressure for hemorrhage control.
Tourniquet use, especially for prolonged periods, has been considered to increase the incidence of amputation of an injured extremity. Any medical personnel applying a prehospital tourniquet for extremity vascular injury should clearly document its necessity as a lifesaving antiexsanguination device when direct pressure fails and should understand the risk that a tourniquet may save a life but result in loss of an extremity. Currently, however, a growing number of authors have begun to support increased prehospital tourniquet use for diagnosed or suspected extremity vascular injuries. [6, 7]
Pathophysiology
As noted by the preponderance of penetrating injury in the published medical literature, the vascular tree, both arterial and venous, appears to have some limited natural protection from stretching and bending, which results in fewer blunt injuries to the extremity vasculature following trauma. The smooth muscle of the arterial media protects the patient from both stretch-type injuries and minor puncture wounds, which heal spontaneously in most cases. The smooth-muscle layer also offers mild protection from death due to ongoing hemorrhage.
When the arterial vessel is transected, vascular spasm coupled with low systemic blood pressure appears to promote clotting at the site of injury and to preserve vital organ perfusion better than is the case with ongoing uncontrolled hemorrhage. This partially explains the prehospital finding that in the subset of penetrating trauma, limited or no fluid resuscitation until arrival at the hospital may improve patient survival and outcome.
Etiology
Extremity vascular injury may result from penetrating injury (eg, gunshot wounds [8] or knife injuries), but not all penetrating injuries are violent in nature. Many penetrating extremity injuries reported in the literature are from industrial accidents (eg, nail guns) or are iatrogenic complications of vascular access procedures for other medical problems.
Blunt injuries causing vascular injury typically result from motor vehicle accidents but may include falls, assaults, and crush injuries. Fractured long bones or dislocated joints frequently increase the overall risk of vascular injury, but certain injuries (eg, posterior knee dislocation) are more likely to cause vascular injury than other injuries (eg, a Colles fracture of the wrist, which rarely results in radial or ulnar artery injury).
The worldwide increase in explosive-type injuries constitutes an emerging third modality that combines the pathology of both blunt and penetrating injury to the extremities. Terrorist bombings, civilian land mine injuries, and combat-related injuries are becoming more common, and all clinicians will undoubtedly encounter these patients at some time in their career.
Epidemiology
The actual frequency of extremity vascular injuries worldwide is difficult to quantify.
In the United States, it is possible to separate iatrogenic vascular injury from traumatic injury and to reference hospital discharge data for the frequency of diagnosis codes. However, this method may significantly underestimate the actual frequency, depending on the method used to code the diagnosis and the importance and ranking attached to the diagnosis. In many cases, government report forms only record the top three discharge diagnostic codes, with the result that codes due to iatrogenic injury may be missed.
The increased interest in the United States has led to efforts to derive more precise incidence figures. In the late 1980s, Mattox et al [9] and Feliciano et al [10] documented an increasing number of iatrogenic vascular injuries occurring in Houston over the preceding few decades, an observation that is probably mirrored nationwide.
Data on blunt and penetrating injury are somewhat easier to derive. In wartime circumstances, the number of injuries may be extreme. Extremity vascular injuries have been documented during episodes of armed conflict as far back as the Greek and Roman civilizations and undoubtedly occurred before those eras.
Extremity amputation was the most common procedure performed by military surgeons in the US Civil War and World War II. DeBakey and Simeone calculated that the amputation rate from vascular injuries in World War II was higher than 40%. [11] Amputation was primarily a means of saving the life of the soldier in an era with no antibiotics, limited surgical technology, and no critical care.
With advances in general medical and surgical science and concomitant improvements in military technology, the amputation rate from vascular injury in the Korean War and the Vietnam War dropped to approximately 15%. Rich et al collected the vascular database information that has provided modern surgeons with an invaluable source of data that set the standard for management of extremity vascular injury. [12, 13]
Sherif reported 224 extremity vascular injuries in 18 months during the Afghanistan War (ie, ~150/y). [14] Fasol et al reported 94 patients in 3 months (ie, ~376/y) on the Thailand-Cambodia border. [15] In both studies, antipersonnel mines caused the majority of civilian extremity vascular injuries.
Using data from The Joint Theater Trauma Registry, one study evaluated the epidemiology of vascular injury in the wars of Iraq and Afghanistan by identifying the categorization of anatomic patterns, management of casualties, and mechanism of injury, including explosive, gunshot, and other injuries. [16] The study found that the rate of vascular injury in modern combat is five times higher than that in previous wars and varies according to operational tempo, mechanism of injury, and theater of war.
Newer methods of reconstruction, including endovascular surgery, are now applied to nearly half of all vascular injuries and should be a focus of training for combat surgery.
At a university teaching hospital in Australia, Tobin [17] reported 10 cases of extremity vascular injury per year; in Tbilisi, Georgia, Razmadze [18] reported 10.5 cases per year; in Sweden, Kjellstrom and Risburg [19] reported 8.2 cases per year; and in Oxford, United Kingdom, Magee et al [20] reported 4.7 cases per year. Penetrating injuries, both violent and nonviolent, predominated as the causes of vascular injuries in these reviews.
In the United States, the situation is similar, though numbers are generally higher. Humphrey et al [21] reported 12.4 extremity vascular injuries per year at a rural trauma center in Missouri; Feliciano et al [10] reported approximately 55 lower-extremity vascular injuries per year at Ben Taub General Hospital (a high-volume urban trauma center) in Houston, Texas. In both extremes, the predominant cause of injury, especially in isolated vascular injury, was penetrating trauma.
As Mattox et al [9] and Feliciano et al [10] pointed out, the number of iatrogenic vascular injuries increased significantly after 1958 as more and varied physician specialties began to access the vascular tree. [22]
Prognosis
In 1986, Floyd and Kerstein [23] documented 10 patients with successful vascular reconstructions; however, in every case, the patients' outcome included a permanent disability that was moderately severe to severe. In most cases, the disability was due to concurrent partial or complete nerve injury. In addition, whereas no early amputations were necessary, there was a 40% amputation rate.
In 1994, Humphrey et al [21] noted a reduction in the amputation rate from 18% to 7%, with a stable 4.8% patient mortality, after the institution of a helicopter transport system in rural Missouri.
In 1996, Magee et al [20] reported a 6% amputation rate and a 19% complication rate at 6-month follow-up in the United Kingdom. However, no information was noted regarding disability.
In 1999, Razmadze [18] reported a 16% early and late amputation rate, with a 7.6% patient mortality in the former Soviet republic of Georgia.
Siddique and Bhatti studied 54 patients who underwent vascular surgical intervention at a military hospital in Ralwalpindi, India, from 2008 to 2010. [24] Penetrating trauma was the cause in 34 patients. The study concluded that early recognition and revascularization were the keys to saving more than 90% of the limbs.
Scott et al surveyed 214 patients about long-term quality of life and function after wartime extremity vascular trauma. [25] They found that severe injury and chronic pain resulted in unfavorable physical and mental outcomes.
In a retrospective study (N = 31; 54 vessels) designed to identify risk factors for failed limb salvage after revascularization during the acute postoperative period in patients who had sustained blunt leg trauma with vascular injuries, Al-Zoubi et al found that the presence of severe multisegmental bone fractures, a prolonged ischemic time (>10 hr), and a Mangled Extremity Severity Score (MESS) of 9 or higher were significant predictors of limb loss. [26]
In a retrospective study (N = 56) aimed at determining amputation rates and causative factors for failed revascularization leading to amputation in patients undergoing primary limb salvage for lower-extremity vascular injuries, Ali et al reported that secondary amputation was performed in 32.1% of cases. [27] The leading causes of revascularization failure were thrombosis and infection. Factors associated with limb amputation were the type of injury, the site of arterial injury, and the presence of concomitant bony injuries.
These data clearly show that extremity vascular injury, especially those with concomitant nerve, bone, and significant soft-tissue injury, can be disastrous to patients. Early and aggressive vascular repair improves patient outcome but cannot reverse the effects of some injuries. Amputation and disability rates remain high, even with optimal transport, trauma care, and successful operative intervention.
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Crushed and mangled foot of a person who was involved in a motor vehicle accident.
