Evaluation and Treatment of Vascular Injuries

Disclaimer: The views in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the US government.

I am a military service member. This work was prepared as part of my official duties. Title 17 U.S.C. 105 provides that “Copyright protection under this title is not available for any work of the United States Government.” Title 17 U.S.C. 101 defines a US government work as a work prepared by a military service member or employee of the US government as part of that person's official duties.

Acknowledgment:

The author thanks John Kopitzke, Casey Price, and Kathryn Foster from the Visual Graphics Department for their significant contributions to this chapter, providing the photography, video editing, and original artwork.

Introduction

One of the chief fascinations in surgery is the management of wounded vessels. —WILLIAM STEWART HALSTED, 1912

There are two pressing concerns in vascular trauma: hemorrhage and ischemia. Uncontrolled hemorrhage is widely recognized as the leading cause of preventable traumatic death in both the civilian and military environments. Prolonged limb ischemia is associated with rates of amputation of over 80%. Recognition and timely diagnosis and management of vascular injuries are therefore vital to save lives and limbs. As an orthopaedic surgeon, you will often be the first to evaluate these injuries, either before or in the absence of a vascular or trauma surgeon. Having a complete grasp of the approach to the patient with a potential vascular injury, including the three priorities of diagnosis, hemostasis, and revascularization, will expedite the complete care of the patient and lead to substantially better outcomes in terms of lives saved and limbs salvaged.

The target audience for this chapter is the orthopaedic surgeon or resident with some exposure to vascular surgery. It is assumed that the reader does not practice vascular or trauma surgery on a regular basis, and to that end, this chapter focuses on straightforward techniques that have broad applicability. Advanced procedures such as endovascular management options are briefly addressed to provide the reader with general awareness, but the focus remains on techniques with which the orthopaedist should be familiar and should be able to perform independently. The goal is to provide the tools necessary to either manage a straightforward problem or temporize a complicated situation and set the patient and the vascular specialist up for success. Temporizing has vastly different meanings depending on the environment. In a tertiary care hospital, it may mean holding pressure while a vascular surgeon colleague is summoned to the operating room, whereas for a far-forward military surgeon or an orthopaedic surgeon taking a primary trauma call, it may mean shunting, performing a temporary interposition graft, or ligating an axial artery if the patient is hours or days away from the next level of care.

It cannot be overstated that the focus should be on straightforward approaches that work. Become familiar with a few workhorse vascular exposures, techniques, and instruments and minimize the process variation. This will leave your mind less encumbered by unfamiliar details as you are challenged with the unwelcome sight of rapid bleeding or a pale limb.

Key Points

Vascular injury is uncommon in most orthopaedic trauma, yet there are known patterns of injury associated with a higher risk of vascular injury.
Hemorrhage control takes precedence over revascularization.
Rely on a few versatile techniques, exposures, and instruments.
Develop a familiarity with the expertise and limitations of each new practice environment.
Utilize techniques that fail well and have bail-out options.
Look for hard signs of vascular injury, but be alert for soft signs; recheck the patient regularly to assess for evolving injury patterns.
Palpate, examine, and document all pulses. Use an arterial pressure index for quantitative assessments.
Repeat examinations liberally, after any intervention, and after any functional or physiologic deterioration.
The decision between damage control and definitive repair should include the patient's physiology, the immediate resources, the surgeon's experience, and the availability of expertise in the evacuation or transport chain.

Epidemiology and Outcomes of Vascular Injury in Orthopaedic Trauma

Vascular injury is relatively uncommon in the setting of orthopaedic trauma; superficial femoral artery injury is seen in approximately 1% of femoral fractures, and tibial artery injury occurs in less than 3% of tibial fractures. Risks for vascular injury include high-energy mechanisms such as blast or high-powered firearm injury, open fractures, and joint dislocations. Table 16.1 presents a list of potential arterial injuries associated with orthopaedic trauma. Although much of the mortality and morbidity of extremity injury may be due to the overall burden of trauma sustained by the patient, isolated extremity arterial injury is also correlated with significant mortality and amputation risk. A National Trauma Databank (NTDB) study found a mortality rate of 2.8% and an amputation rate of 6.5% among patients with isolated infrainguinal vascular injury. Injuries to the common femoral and superficial femoral artery, which are more difficult to control with tourniquets compared with more distal arterial trauma, were responsible for most of the deaths in this study. As the point of injury moves distally on the lower extremity, the risk of mortality decreases, but the amputation risk increases, likely due to poor collateral circulation about the knee. Injuries to the common and superficial femoral artery are associated with a 10% rate of amputation, which increases to 15% to 21% for injury to the popliteal artery. Risk factors for amputation include occlusion of a bypass graft, a combined above- and below-knee arterial injury, the presence of compartment syndrome, arterial transection, and a compound fracture. One of the most powerful predictors of amputation, however, is a delay in diagnosis. A delay in revascularization of over 8 hours is associated with amputation rates of over 80%. Although advances in the management of vascular injury have reduced the overall risk of amputation in civilian trauma to less than 5%, long-term disability in terms of skeletal and nerve injury persists in 20% to 50% of patients. Iatrogenic injury is another source of vascular trauma in this patient population. Table 16.2 lists common injuries associated with orthopaedic procedures. In a review of 182 cases of vascular injury during internal fixation procedures of the proximal femur, the profunda femoris artery and its branches were the most commonly injured vessels, responsible for 130 out of 166 cases (78%). The most common injury was a pseudoaneurysm (67%), followed by acute hemorrhage (23%). Mortality was 6.6% in this study, highlighting the critical need to anticipate and prevent these injuries.

Table 16.1

Arterial Injuries Associated With Fractures and Dislocations

This table has been reproduced with permission of the International Association for the Study of Pain® (IASP). The table may not be reproduced for any other purpose without permission.

Fracture or Dislocation	Artery Injured
Upper Extremity
Fracture of clavicle or first rib	Subclavian artery
Anterior dislocation of shoulder	Axillary artery
Fracture of neck of humerus	Axillary artery
Fracture of shaft or supracondylar area of humerus	Brachial artery
Dislocation of elbow	Brachial artery
Lower Extremity
Fracture of shaft of femur	Superficial femoral artery
Fracture of supracondylar area of femur	Popliteal artery
Dislocation of the knee	Popliteal artery
Fracture of proximal tibia or fibula	Popliteal artery, tibioperoneal trunk, tibial artery, or peroneal artery
Fracture of distal tibia or fibula	Tibial or peroneal artery
Skull, Face, or Cervical Spine
Basilar skull fracture involving sphenoid or petrous bone	Internal carotid artery
Le Fort II or III fracture	Internal carotid artery
Cervical spine, especially foramen transversarium	Vertebral artery
Thoracic Spine	Descending thoracic aorta
Lumbar Spine	Abdominal aorta
Pelvis
Anterior-posterior compression	Thoracic aorta
Subtypes of pelvic fractures	Internal iliac, superior gluteal, or inferior gluteal artery
Acetabular fracture	External iliac, superior gluteal, or femoral artery

Table 16.2

Acute or Delayed Arterial Injuries Associated With Orthopaedic Operative Procedures

Orthopaedic Procedure	Artery Injured
Upper Extremity
Clavicular compression plate or screw	Subclavian artery
Anterior approach to shoulder	Axillary artery
Closed reduction of humeral fracture	Brachial artery
Lower Extremity
Total hip arthroplasty	Common or external iliac artery
Nail or nail-plate fixation of intertrochanteric or subtrochanteric hip fracture	Profunda femoris artery
Subtrochanteric osteotomy	Profunda femoris artery
Total knee arthroplasty	Popliteal artery
Anterior or posterior cruciate ligament reconstruction	Popliteal artery
External fixator pin	Superficial femoral, profunda femoris, popliteal, or tibial arteries
Spine
Anterior spinal fusion	Abdominal aorta
Lumbar spine fixation device	Abdominal aorta
Resection of nucleus pulposus	Right common iliac artery and vein, inferior vena cava
Pelvis
Posterior internal fixation of pelvic fracture	Superior gluteal artery
Excision of posterior iliac crest for bone graft	Superior gluteal artery

History and Physical Examination

Signs of Vascular Injury

The signs of vascular injury are classically divided into two broad classes. Hard signs represent clear evidence of a vascular injury, whereas soft signs are suggestive of vascular injury and should prompt further evaluation.

Hard Signs

Hard signs of vascular injury can be divided into three major categories: active hemorrhage, frank ischemia, and arteriovenous fistula. In a study of all trauma patients admitted with extremity injury, hard signs occurred in 5.5% of cases. Among patients with known vascular injuries in the PROOVIT vascular trauma registry, hard signs were present in 29.3% of patients. Patients with hard signs of vascular injury should undergo immediate surgical exploration and repair. In cases of multilevel injury such as a shotgun blast, intraoperative angiography is useful for localizing the vascular injury. An arteriovenous fistula, a pathologic connection between the arterial and venous systems, generally presents in a delayed fashion and can be associated with diminished arterial flow, which would be apparent on an arterial pressure index. Arteriography is helpful for definitive diagnosis. The examination may reveal a palpable thrill (a continuous buzzing sensation upon palpation of the venous structures) or an audible bruit when auscultating the area.

Soft Signs

Soft signs can also be divided into three classes: clear signs of diminished arterial perfusion, evidence of significant prior blood loss, and signs of injury to structures adjacent to major arteries or veins, otherwise known as proximity injury. The vital consideration is that a soft sign may portend a severe vascular injury ; they are associated with vascular injury in 3% to 25% of cases, although only 3% to 20% will require operative intervention, depending on the combination of soft signs present. In the LA County experience, the most common soft sign was a nonexpanding or nonpulsatile hematoma (36%) and abnormal arterial pressure index (API; 36%), followed by venous oozing (22%) and diminished pulses (19%).

The most obvious of the soft signs is a weak (and likely asymmetric) pulse. Maintain a very low threshold to obtain an API (see the following section for details) in any setting suggestive of a vascular injury. It is also wise to obtain pressure measurements before and after an intervention such as fracture reduction. If the API is less than 0.9, this should prompt further investigation for occult vascular injury. A stable hematoma or a history of major bleeding is suggestive of injury to a major vessel. In some cases, the only clue to the presence of a vascular injury may be the damage done to structures known to be anatomically adjacent. Dysfunction of a nerve that runs in a major neurovascular bundle should prompt evaluation of the vessels of this bundle. The simple proximity of a wound tract to a neurovascular bundle is historically considered a soft sign, but in a study at LA County Trauma, no vascular injuries were identified in patients who underwent computed tomography (CT) imaging for proximity alone in the absence of other findings.

Hemorrhage

Halstead stated that “The only weapon with which the unconscious patient can immediately retaliate upon the incompetent surgeon is hemorrhage.” It is, then, hemorrhage that is the most immediate concern in any trauma scenario. The patient with uncontrolled bleeding is the most critical of trauma patients; failure to rapidly recognize and control the bleeding will promptly lead to death. Uncontrolled hemorrhage has been widely recognized as the leading preventable cause of trauma deaths in both the civilian and military trauma populations. This has led to a shift in the trauma resuscitation algorithm to prioritize control of massive hemorrhage ahead of other interventions such as airway and respiratory support. A suggested algorithm for the approach to the patient with a suspected vascular injury is presented in Fig. 16.1 . Patients who present in extremis from hemorrhage should be taken immediately to the operating room (OR) for resuscitation and immediate vascular control. The right-turn resuscitation , a term referring to bypassing the emergency department and moving directly to the OR with a patient in extremis, has been shown to reduce the time to resuscitation and improve survival.

Fig. 16.1, Approach to the patient with suspected extremity vascular injury.

Extremity Hemorrhage

Manual Pressure and Hemostatic Dressings

In the actively bleeding extremity, the first step is to put pressure directly on the wound. The intent is to counter the blood pressure within the bleeding vessel, leading to temporary hemostasis. In most cases, there will be a wound tract, which should be packed with a space-occupying material such as Kerlix gauze or a topical hemostatic agent such as QuickClot Combat Gauze (Z-Medica, Wallingford, CT). When these dressings are applied, at least 3 minutes of direct pressure should be applied by the medical provider.

Tourniquets

If extremity bleeding cannot be controlled with manual pressure or hemostatic dressings, the next step is the application of a tourniquet. Recent experience from the combined multinational military trauma literature has demonstrated that the use of tourniquets clearly saves lives, and when commercial devices are applied properly, they have a low risk of significant complications. The advantages of tourniquets are significant: they are easy to apply and can be applied by the patient if necessary, they provide consistent occlusion pressure throughout transport, and they free the medical provider to assume other tasks. In resource-limited environments, such as tactical engagements (e.g., an active shooter) or mass casualty (e.g., a terrorist bombing incident), the liberal use of tourniquets will free providers from holding pressure and can act as a force multiplier. In the emergency department, they allow the surgeon to focus on other priorities once the bleeding is temporized. Known complications of tourniquet use include temporary nerve palsy at the point of tourniquet application in 1.4%, myonecrosis in 1.5%, acute renal failure due to reperfusion injury in 1%, and vascular thrombosis in 3%. Other potential adverse events include a significant reperfusion injury once the tourniquet is removed, although it is difficult to predict in which patients this will occur. The duration of occlusion, the amount of ischemic muscle (i.e., proximal thigh tourniquet versus below-knee tourniquet), the temperature of the ischemic limb, and the overall metabolic state (i.e., global trauma burden) of the patient will all contribute to the risk of reperfusion injury and renal failure in ways that as yet cannot be predicted with certainty. Improper application of a tourniquet that causes venous outflow obstruction with persistent arterial inflow can lead to increased bleeding and can threaten the patient's life. The associated amputation rate of 35% and fasciotomy rate of 25% are a result of the traumatic injury itself and have not been deemed to be a result of the tourniquet application.

The general guidelines of proper tourniquet use are to place the tourniquet as distal as possible to limit the volume of ischemic tissue but at least 5 cm proximal to the site of injury to spare joints as much as possible, to apply directly over skin to avoid slippage (or with a soft dressing such as Webril under the tourniquet in the hospital setting to protect the skin), and to convert the tourniquet as quickly as possible to either another type of dressing or to achieve surgical bleeding control. In selecting a tourniquet, two facts are worth remembering. First, there have been no documented cases of permanent limb dysfunction or limb loss from tourniquets left in place for 2 hours or less. Second, the wider the tourniquet, the lower the pressure required for occlusion, and the lower the risk of nerve dysfunction. Therefore it is wise to select the widest possible tourniquet that will not interfere with the operative field. Once in place, it is imperative to move quickly to definitive vascular control.

Tourniquet Conversion

Although tourniquets are clearly lifesaving in properly selected patients, they have a substantial risk in terms of threat to the limb and ischemia-reperfusion injury. Therefore “tourniquet conversion,” meaning removal of the tourniquet and replacement with a hemostatic or pressure dressing, should occur as soon as possible for unnecessary tourniquets. The challenge is identifying which are unnecessary. In combat environments, especially care under fire, tourniquets are applied liberally, with little ability for accurate diagnosis. In the Israeli experience, there was a wide variety of indications for tourniquet application; the most common was a mass casualty situation (57%), followed by amputation (34%) and “under fire” situation (34%). Another 3% of tourniquets were reportedly applied “due to darkness,” reflecting an inability to assess the casualty. Overall, 47% were considered “not indicated.” As military management strategies for combat trauma are translated to the civilian setting, the prehospital use of tourniquets is increasing, currently occurring in 20% of cases of extremity vascular injury. With the increasing incidence of active-shooter and other terrorist events, there is a growing mandate to train the lay public to control traumatic hemorrhage. Application of tourniquets by bystanders may soon become a reality, and those providing surgical care will need to be prepared for this.

In most cases, the surgeon will encounter a patient with a tourniquet already in place. In cases of short evacuation, it is also likely that no attempts at conversion will have yet been made, and therefore the first task is to determine whether the tourniquet is necessary per the guidelines previously discussed. Carefully loosen (but do not remove) the tourniquet and examine the limb. If bleeding recurs, attempt to control it with hemostatic dressings. If this fails, reapply the tourniquet or convert it to a pneumatic device and proceed to the OR for surgical control.

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