You are in: eMedicine Specialties > Vascular Surgery > MEDICAL TOPICS Extremity Vascular TraumaArticle Last Updated: Sep 12, 2006AUTHOR AND EDITOR INFORMATIONAuthor: H Scott Bjerke, MD, FACS, Clinical Associate Professor, Department of Surgery, Indiana University School of Medicine, Medical Director of Trauma Services, Methodist Hospital, Clarian Health Partners, Inc H Scott Bjerke is a member of the following medical societies: American Association for the History of Medicine, American Association for the Surgery of Trauma, American College of Surgeons, Association for Academic Surgery, Eastern Association for the Surgery of Trauma, Midwest Surgical Association, National Association of EMS Physicians, Pan-Pacific Surgical Association, Royal Society of Medicine, Southwestern Surgical Congress, and Wilderness Medical Society Coauthor(s): Edward J Jakubs, MD, Staff Physician, Department of Surgery, Indiana University School of Medicine; David FE Stuhlmiller, MD, FACEP, EMS Medical Director, Emergency Medical Associates of Westchester Medical Center; Medical Director, LifeNet of New York, An Air Methods Company; Medical Advisor, International Association of Flight Paramedics Editors: Ernest Dunn, MD, Program Director of General Surgery, Director of Trauma and Critical Care, Clinical Associate Professor, Department of Surgery, Methodist Hospitals of Dallas, University of Texas Southwestern; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Robert L Sheridan, MD, Assistant Chief of Staff, Chief of Burn Surgery, Shriners Burns Hospital; Associate Professor of Surgery, Department of Surgery, Division of Trauma and Burns, Massachusetts General Hospital and Harvard Medical School; Paolo Zamboni, MD, Professor of Surgery, Chief of Day Surgery Unit, Chair of Vascular Diseases Center, University of Ferrara, Italy; William H Pearce, MD, Chief, Division of Vascular Surgery, Violet and Charles Baldwin Professor of Vascular Surgery, Department of Surgery, Northwestern University School of Medicine Author and Editor Disclosure Synonyms and related keywords: extremity vascular trauma, land mines, motor vehicle accidents, amputation, soft tissue injury, penetrating trauma, blunt trauma INTRODUCTIONPatients with extremity vascular traumas present daily in emergency departments (EDs) and trauma centers worldwide. While 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. History of the ProcedureExtremity 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 amputations were the most common procedure performed by military surgeons in the US Civil War and World War II. DeBakey and Simeone calculated the amputation rate from vascular injuries in World War II as greater than 40%. 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 the advance of general medical and surgical science and a concomitant improvement in military technology, the amputation rate from vascular injury in the Korean War and the Vietnam War dropped to approximately 15%. Rich and colleagues collected the vascular database information that has provided modern surgeons with an invaluable source of data that sets the standard for management of extremity vascular injury. ProblemCivilian extremity vascular injury, as with the wartime experience, is most prevalent in cases of penetrating trauma; however, unlike the military experience, this penetrating trauma is usually due to knife wounds or low-velocity handgun injuries. Fortunately, high-velocity assault weapon injuries and explosive injuries are rare 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 trauma surgeons 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. FrequencyThe 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 based 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 3 discharge diagnostic codes, enough to potentially miss codes due to iatrogenic injury. With the increased interest in the United States, more precise incidence numbers may be observed in the next few years. Mattox et al and Feliciano et al have shown an increasing number of iatrogenic vascular injuries occurring in Houston over the last 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. Sherif reported 224 extremity vascular injuries in 18 months during the Afghanistan War, roughly 150 per year. Fason et al reported 94 patients in 3 months (ie, approximately 376/y) on the Thailand-Cambodia border. In both studies, antipersonnel mines caused the majority of civilian extremity vascular injuries. At a university teaching hospital in Australia, Tobin reported 10 cases per year of extremity vascular injuries; in Tbilisi, Georgia, Razmadze reported 10.5 cases per year; in Sweden, Kjellstrom and Risburg reported 8.2 cases per year; and in Oxford, United Kingdom, Magee et al 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, although numbers are generally higher. Humphrey et al reported 12.4 extremity vascular injuries per year at a rural trauma center in Missouri; Feliciano et al reported approximately 55 lower extremity vascular injuries per year at Ben Taub General Hospital (a high-volume urban trauma center) in Houston, Tex. In both extremes, the predominant cause of injury, especially in isolated vascular injury, was due to penetrating causes. Mattox et al and Feliciano et al have also pointed out that the number of iatrogenic vascular injuries has significantly increased since 1958 as more and varied physician specialties access the vascular tree. (See Caps' excellent article on the epidemiology of vascular injuries in Seminars in Vascular Surgery [1998] and Mattox and colleagues' paper on epidemiological evolution of these injuries in Annals of Surgery [1989]). EtiologyExtremity vascular injury may result from penetrating injury (eg, gunshot wounds, 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 physicians will undoubtedly encounter these patients sometime in their career. PathophysiologyAs 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 that which occurs 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. ClinicalWorldwide, patients with extremity vascular injuries most frequently present after a penetrating injury to an extremity. In the United States, high-speed motor vehicle accidents, often with fractures or dislocations, result in the next largest group of patients. In patients with large lacerations or open wounds, persisting or increasing hemorrhage with resuscitation is an early indication of vascular injury requiring operative exploration. Vascular injuries can be classified clinically into hard signs and soft signs of injury based on examination. Classic so-called hard signs of vascular injury include the following:
These signs are used to identify patients requiring surgical intervention. A finding of cool, cold, and pulseless extremities may be attributable to a low systemic blood pressure, but isolated pulse abnormalities and significant variation in pulse quality from side to side are strong indicators of underlying proximal vascular injury. Neurologic deficit, delayed capillary refill, and bony abnormalities should increase the suspicion of extremity vascular injury and the need for emergent arteriography or surgical exploration and repair. Soft signs of vascular injury include the following:
Clinical examination and reexamination remain the mainstays for identifying and treating these wounds. Clinical examination and findings should determine the need for adjunctive studies such as noninvasive Doppler ultrasound and arteriography. The physical examination may be augmented by measurement of the ankle-brachial index (ABI), also referred to as the arterial pressure index in the literature. Measurement of the ABI is a standard component in the evaluation of atherosclerotic peripheral vascular disease, and its value extends to the identification of penetrating injuries to extremity vessels. Both hard and soft signs help direct the physician to the best diagnostic and treatment options for an individual patient. INDICATIONSIn general, hard signs (eg, change in pulse quality compared to the opposite extremity, loss of pulse in the extremity) are absolute indications for further diagnostic studies (eg, arteriogram, exploration and direct visualization in the operating room). Softer signs (eg, temperature change, color change, delayed capillary refill, neurologic deficit) should alert the clinician to the need for close observation and monitoring. If the ABI is higher than 0.9, many authors advocate observation, but if the ABI is lower than 0.9, further evaluation is warranted. In these cases, many authors now recommend duplex Doppler vascular studies as a rapid, noninvasive method of assessing vascular injury. However, an arteriogram in stable patients and operative exploration in unstable or bleeding patients remain the criterion standards of care. RELEVANT ANATOMYA thorough knowledge of basic medical school anatomy of the extremities is essential in the evaluation and management of extremity vascular injuries. While it is often possible to directly visualize an arterial injury 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 minimizing incision length and surgical tissue dissection. 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 use 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. The use of tourniquets, especially those left for prolonged periods, markedly increases 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 anti-exsanguination device when direct pressure fails and should understand that, in most cases, a tourniquet saves a life but results in loss of an extremity. CONTRAINDICATIONSPreexisting renal insufficiency and allergies (seafood, iodine, contrast dye) are relative contraindications for arteriography in the assessment of vascular injury of an extremity. Pre-angiography volume resuscitation and sodium bicarbonate may help minimize the complications noted above. Persistent massive hemorrhage and hemodynamic instability are principal contraindications for any diagnostic studies, and patients with these conditions require urgent operative exploration for diagnostic and therapeutic measures. Duplex Doppler studies may provide important information regarding vascular injury in most stable patients who have contraindications to arteriography. WORKUPLab Studies
Imaging Studies
Other Tests
StagingOrgan injury scaling may be helpful in the acute setting but should not override clinical experience and individual patient needs. Vascular injury scaling is also helpful for epidemiological study, peer review, and coding and billing. For information regarding organ injury scaling of peripheral vascular injuries currently sanctioned by the American Association for the Surgery of Trauma, see the study by Moore et al. TREATMENTMedical therapyMedical therapy alone is rarely an option in penetrating or blunt trauma to the extremity vasculature with hard signs. Asymptomatic patients or patients with only soft signs can often be observed, but this is best performed by a surgeon who is prepared to operate if the clinical examination changes. The observation must be performed with the understanding that if the examination findings change or if hard signs develop, surgical intervention is necessary. While pharmacologic anticoagulation is a viable therapy for arterial thrombosis in some situations, acute injury of the arteriovenous tree usually requires surgical intervention and mechanical repair. Limited anticoagulation or antiplatelet drugs may be helpful after vascular repair, especially with prosthetic material, but carefully weigh the benefit of these drugs against the potential for hemorrhage in other injured tissue, especially with concurrent brain or spinal injury. Surgical therapySurgical intervention when suspecting peripheral vascular injuries 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. Timing of surgical intervention can be critical to outcome in extremity vascular injury. Vascular reconstruction that occurs within 3 hours of injury is generally accepted to have the best outcome. While this can frequently be accomplished in urban Level 1 Trauma Centers, it becomes more difficult in rural areas where availability of rapid EMS transport, geographic location of the hospital, and availability of interventional radiology and surgical subspecialists may be limited. In most cases in which the injured segment is 1 cm or less, dissecting and freeing edges and performing a primary anastomosis is frequently possible. Take care to avoid traction on perforating branches or excessive dissection, which may devascularize surrounding tissue. Attention to vascular surgical technique should minimize tension on the vessel and stricture at the anastomotic site. In more severe cases with multiple associated injuries, hemorrhage control by ligation of actively bleeding arterial or venous vessels may be all that is possible. Tissue viability distal to an arterial ligation depends on regional arterial anatomy, collateral blood flow, preexisting atherosclerotic disease, competent venous outflow, and volume status. Although venous ligation is counter-intuitive, it may carry a higher risk than arterial ligation. Certain vessels, such as the popliteal vein, carry a high postligation amputation rate, while the rate for femoral or external iliac vein ligation is statistically lower. The risk of subsequent amputation after any ligation is much higher than after vascular repair, but patients with severe brain injury or hemodynamic instability may not tolerate a 2- to 3-hour operation to repair a vascular injury, and damage-control techniques with arterial or venous ligation may save lives. Use of intravenous chemical vasoconstrictors (phenylephrine [Neo-Synephrine,norepinephrine) should be minimized in the postoperative period. If the patient's condition and hemodynamic status allow prolonged operative intervention, general replacement of an injured peripheral arterial segment is accomplished with an autologous vein. The saphenous or cephalic veins harvested from the same or contralateral extremity are the most commonly used vein segments. Polytetrafluoroethylene (PTFE) can be used in some situations but is usually reserved for above-knee or above-elbow applications. PTFE has been successfully used in contaminated fields with a low infection rate (Shah, 1984) for both venous and arterial reconstruction. In some trauma centers, PTFE is the preferred conduit and has replaced the use of an autologous vein in above-knee, below-knee, and elbow reconstruction. Stevens et al (1987) summarize the causes of failure of arterial reconstruction. Typically, in most acute situations, venous injuries are primarily ligated, but, in a select number of injuries in hemodynamically stable patients, venous reconstruction may be an option. Very little prospective data is available in the trauma literature, but readers are directed to an older but more pertinent retrospective review in the Journal of Vascular Surgery for more information (Nypaver, 1992). After reconstruction in the stable patient or vascular ligation in damage-control situations has been completed, the surgeon should consider the risk of reperfusion injury and the potential for compartment syndrome. While this is more common in distal lower extremities, it is also possible in proximal compartments and the upper extremities (see Image). Fasciotomies increase the risk of infection, increase fluid and blood loss, and eventually require reoperation for either skin closure or skin grafting. These complications should be weighed against the risk of compartment syndrome with risk of limb loss, renal failure from myoglobin release, and tissue gangrene. Monitoring compartment pressures in the postoperative period in conjunction with the clinical examination is possible, but prophylactic fasciotomies, even with the attendant risks noted above, are to be recommended in the more severe cases. The most challenging injuries are those of the mangled extremity, with concurrent bony, soft tissue, nerve, and vascular injury. The treatment of these complex injuries precludes detailed description in a short review, but many authors have evaluated the factors that determine the risk of amputation. Scoring systems have been developed as a means to predict amputation and functional outcome. Scoring systems such as Mangled Extremity Syndrome Index (MESI), Mangled Extremity Severity Score (MESS), Predictive Salvage Index (PSI), and Limb Salvage Index (LSI) have been reviewed by Durham et al. Prediction of amputation was sensitive and specific, but prediction of functional outcome was universally poor. The MESS score appears to be the most commonly used method and is based on criteria that include (1) degree of skeletal/soft tissue injury, (2) limb ischemia, (3) shock, and (4) patient age (Heflet et al, 1990). Note that some authors have been unable to validate individual scoring systems, and no one system is universally accepted (Bonanni et al, 1993). Interventional radiologic techniques should also be noted as an option in acute injury, but the indications and timing are still being developed. Coil embolization of complications of vascular trauma, such as arteriovenous malformations and pseudoaneurysms, are more commonplace and are described in more detail in Follow-up care. Endovascular stenting has been reported for acute traumatic injuries since 1994, but it is not yet available in most facilities (Veith and Marin, 1996 et al, Weiss and Chaikof, 1999). Long-term outcome and complication rates have not been calculated, and although the technique is promising, more long-term follow-up study is necessary. Preoperative detailsIf planning reconstruction, the best results have been reported in patients who are hemodynamically stable with normal laboratory findings and preoperative arteriography to localize the injury. In some cases, operative intervention is primarily performed for life-saving hemorrhage control rather than for operative repair with limb salvage. Intraoperative detailsInitial ligation of life-threatening vascular hemorrhage may allow stabilization of patients and subsequent exploration and repair of the injured vessels. In the patient who remains hemodynamically unstable, the surgeon should balance the desire to save the limb with that of preserving the patient's life. Postoperative detailsFrequent monitoring and vascular checks (eg, pulse presence, quality, capillary refill) should continue for the first 24-48 hours. Consideration of anticoagulation and antiplatelet agents should be balanced with the risk of fatal hemorrhage from other injuries (eg, head and chest injuries). Maintain adequate hydration, especially after administration of contrast dye, after episodes of hypotension, and in the presence of concomitant renal injury. A urine output of 20 mL/h or more is ideal in adult patients. Follow-upVascular repair with palpable pulses in the postoperative period rarely requires repeat angiography. If a completion angiogram was not performed in the operating room, duplex Doppler ultrasound may provide a less invasive method of monitoring graft status. Advise patients of the risks and symptoms of thrombosis or vascular occlusion so that they may quickly contact the surgeon or obtain evaluation in a local ED if problems occur. The surgeon should consider the need for anticoagulation or antiplatelet medications (eg, coumadin, aspirin), balancing the overall risk to patients with the needs of the graft and vascular repair. COMPLICATIONSThrombosis of the graft remains the most common complication of vascular injury and blood vessel repair. Narrowing of the vessel with primary repair or kinking of the graft, especially after repetitive orthopedic intervention may compromise volume of flow and may require revision of the repair. Ligation of vessels for emergent hemorrhage control may result in ischemia, leading to amputation more frequently than vascular repair. One of the more difficult situations for patients and surgeons occurs when permanent nerve injury ensues but is diagnosed late because of concurrent head or other injury. Functional vasculature with significant irreparable denervation of motor and sensory components of the extremity usually results in a useless appendage, which causes more problems or complications than amputation. Splinting or bracing the extremity occasionally provides an acceptable functional result and should be considered, but many patients opt for amputation and a functional prosthesis rather than a nonfunctional insensate extremity that requires constant care and monitoring. OUTCOME AND PROGNOSISIn 1986, Floyd and Kerstein 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, while no early amputations were necessary, there was a 40% amputation rate. In 1994, Humphrey et al noted a reduction in the amputation rate from 18% to 7%, with a stable 4.8% patient mortality rate with institution of a helicopter transport system in rural Missouri. In 1996, Magee et al 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 reported a 16% early and late amputation rate, with a 7.6% patient mortality rate in the former Soviet republic of Georgia. 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. FUTURE AND CONTROVERSIESImproved Emergency Medical Services (EMS) systems, faster transport times, availability of interventional radiological techniques, improved surgical technique, and new 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 advancements in other areas, eg, motor vehicle safety, worldwide control and cleanup of antipersonnel mines, and injury prevention programs. MULTIMEDIA
REFERENCES
Extremity Vascular Trauma excerpt Article Last Updated: Sep 12, 2006 | ||||||||||||