g03 vascular injury
TRANSCRIPT
Principles for Evaluation and Treatment of Patients with
Vascular Injury
Timothy McHenry, MD
Overview
• Epidemiology• Types of Injury• Evaluation• Treatment
Mechanisms of Vascular Injury in the Extremities
• Gunshot wound – 54%• Stab wound – 15%• Shotgun wound – 12%• Blunt trauma – 15%• Iatrogenic – 3%
Types of InjuriesActive Hemorrhage
• Laceration
• Partial transection
• Complete Transection
Types of InjuryPotentially non-occlusive
• Contusion with:
– Segmental Spasm
– Thrombosis
– True Aneurysm
Types of InjuryPotentially non-occlusive
• Pseudoaneurysm
• Arteriovenous Fistula
• Intimal Flap
Presentation of Vascular Injury
• First priority is hemorrhage control followed by appropriate diagnostic work-up
Presentation of Vascular Injury
• Dislocations and displaced or angulated fractures: realigned immediately if vascularity is compromised
Evaluation for Vascular Injury• Physical Examination• Doppler Flowmeter• Duplex Ultrasonography• Arteriogram• Local wound exploration should not be done in
an uncontrolled setting• Close coordination with a general or vascular
surgeon recommended
Physical ExaminationHard Signs
• Absent or diminished distal pulses• Active hemorrhage• Large, expanding or pulsatile hematoma• Bruit or thrill• Distal ischemia (pain, pallor, paralysis,
paresthesias, coolness)
Physical ExaminationSoft Signs
• Small, stable hematoma• Injury to anatomically related nerve• Unexplained hypotension• History of hemorrhage no longer present• Proximity of injury to major vessel
Doppler Examination
• Non-invasive adjunct to physical examination• Small, hand-held (non-directional) Doppler flowmeter
provides for subjective interpretation of audible signal• Useful as modality for determining the Ankle-Brachial
Index (ABI)
Doppler
• Normal arterial signals are triphasic or biphasic
Doppler
• Flow distal to a transection may be absent or monophasic and low-pitched due to collateral circulation
Determination of Ankle-Brachial Index
• Appropriate sized blood pressure cuff is placed above the ankle or wrist
• Doppler derived opening pressure of distal artery
• Calculate by dividing ankle pressure by brachial pressure
• Measure injured/ uninjured sides• Normal ABI is 1.00 or greater
ABI Criteria• ABI > 0.9
– Advantages• Strong negative predictor for major vascular injury• Objective noninvasive evidence of vascular
competence– Disadvantages
• Does not exclude all injuries• Not useful in presence of vascular disease
Duplex (B-mode) Ultrasonography
• Direction-sensing Duplex (B-mode) ultrasound allows for visual waveform analysis
• Highly operator dependent• 96-98% accurate in experienced hands• Generally not available during peak trauma
times
Arteriography
• Gold standard for evaluation of peripheral vascular injuries
• Formal arteriograms done in radiology may cause critical delays in diagnosis or intervention
• Single-shot arteriograms done in the emergency room or operating room should be considered in cases where arteriography is indicated.
Indications for Arteriography• Multiple potential sites of injury (shotgun wounds)• Missile track parallels vessel over long distance• Blunt trauma with signs of vascular trauma• Chronic vascular disease• Extensive bone or soft tissue injury• Thoracic outlet wounds• Evaluation of equivocal results from non-invasive tests• Proximity (gsw, knife wound) (controversial)• ABI < .9
Single-shot Arteriogram• 21 or 20 gauge angiocatheter ( at least 2”
long) or single lumen central line or a-line kit
• 3 way stop-cock• 30 cc syringes (x2)• Iodinated contrast (full strength)• Heparinized saline (1,000 IU/liter)• IV extension tubing• Consider inflow and/or outflow occlusion
Single-shot Arteriogram in the Emergency or Operating Room
Summary of Evaluation• Initial priority is to control hemorrhage
– Direct Pressure– Pressure Points– Tourniquet
• If penetrating injury with one or more hard signs of vascular injury then immediate surgical exploration is usually warranted
• If hard signs present with blunt mechanism or multi-site penetrating mechanism then an arteriogram may be warranted
• If soft signs present, consider further diagnostic modalities (usually initially non-invasive)
TreatmentOperative Repair
Indications:• injuries with hard signs of vascular injury
OR
• arteriogram showing occlusion or extravasation
TreatmentNon-operative Observation
• Certain non-occlusive injuries without hard signs (often occult injuries) can be managed conservatively
• Criteria:– Low-velocity injury– Minimal arterial wall disruption– Intact distal circulation– No active hemorrhage
• Serial arteriography or duplex scanning recommended• Close coordination with a vascular or general surgeon
is recommended
Non-operative Management
• Intimal injuries and segmental narrowing are most amenable to conservative care and may resolve over time
• Small pseudoaneurysms sometimes enlarge, become symptomatic and require operative repair
• Asymptomatic acute AV fistulas may be less certain to resolve and should be followed closely
Sequelae of Missed Arterial Injuries
• Deterioration of arterial injury can lead to:– Intimal dissection with resulting occlusion– Arteriovenous fistula– Thromboemboli– Stenosis
• These can cause distal ischemia with significant morbidity:
– Pain– Gangrene– Amputation
Penetrating Arterial InjuryLimb Salvage Rates
• World War II (Debakey and Simeone, 1946)– 2,471 cases– 51% salvage for ligation– 64.2% salvage for repair
• Viet Nam War (Rich et al, 1970)– 1000 cases– 28.5% with concomitant fractures– 87% overall salvage
• Recent civilian (Trooskin et al, 1993)– 50 arterial and 17 venous injuries in 51 patients– 22% with concomitant fractures– 100% salvage– Other recent civilian studies approach a 100% salvage rate as well
Blunt Arterial Injury Salvage Rates
• Have a high amputation rate due to associated soft-tissue and nerve injuries (the mangled extremity)
• These injuries may result in a non-functional limb in spite of a successful revascularization
Mangled Extremity
• Indications for Primary Amputation– Anatomically complete disruption of sciatic or
posterior tibial nerves in adult even if vascular injury is repairable
– Prolonged warm ischemia time – Life threatening sequelae
• rhabdomyolysis
Mangled Extremity
• Relative Indications for Primary Amputation– Serious associated polytrauma– Severe ipsilateral foot trauma
• loss of plantar skin/weight bearing surface– Anticipated protracted course to obtain soft-
tissue coverage and skeletal reconstruction
Variables in Consideration of Limb Viability
• Skin/Muscle Injury• Bone Injury• Ischemia (time, degree)• Type of Vascular Injury• Shock• Age• Infection• Associated injuries (pulmonary, abdominal, head, etc.)• Comorbid Disease (peripheral vascular disease, diabetes
mellitus, etc.)
Classification Systems• Mangled Extremity Syndrome Index (MESI)
– 10 variables• Predictive Salvage Index (PSI)
– 4 variables• Mangled Extremity Severity Score (MESS)
– 4 variables• Limb Salvage Index (LSI)
– 7 variables • NISSSA scoring system
– 5 variables
Mangled Extremity Scoring SystemFactor ScoreSkeletal/soft-tissue injury
Low energy (stab, fracture, civilian gunshot wound) 1Medium energy (open or multiple fracture) 2High energy (shotgun or military gunshot wound, crush) 3Very high energy (above plus gross contamination) 4
Limb Ischemia (double score for ischemia > 6 hours)Pulse reduced or absent but perfusion normal 1Pulseless, diminished capillary refill 2Patient is cool, paralyzed, insensate, numb 3
ShockSystolic blood pressure always >90 mm Hg 0Systolic blood pressure transiently <90 mm Hg 1Systolic blood pressure persistently <90 mm Hg 2
Age, yr<30 030-50 1>50 2
Mangled Extremity Severity Score
• All information for classification available at time of ER presentation
• Simplest to apply of all scoring systems• Most thoroughly studied• A score of less than 7 is supposed to predict
limb salvageability
LEAP Data • 556 lower extremity injuries• prospectively scored—MESS, PSI, LSI, NISSSA,
HFS-97• High specificity (84-98%)• LOW SENSITIVITY (33-51%)• Not a substitute for clinical judgment and experience
for salvage vs amputation decision making
Bosse et al, JBJS, 83-A, 2001
Mangled Extremity Management
• Involves a determination of both the feasibility (restoring viability) and advisability (restoring function) of salvaging the limb
• Should be a coordinated effort of the orthopaedic, vascular and plastic surgeons starting at the initial evaluation of the patient
Fasciotomies
• Prophylactic fasciotomies after vascular repair have been credited as being a major reason for increased limb salvage rates in recent years
• Fasciotomies after prolonged ischemia prevent compartment syndrome that may result from reperfusion injury– The reperfusion injury is delayed and may manifest
after the patient leaves the operating room
Indications for Fasciotomies
• No absolute clinical indications for fasciotomy exist• Subjective criteria
– Extensive soft-tissue or bony injury– Progression of swelling– Compartment tightness
• Objective criteria– Ischemia time greater than 6 hours– Compartment pressure within 20 mm Hg of diastolic blood pressure
Morbidity of Fasciotomies
• Increased risk of infection– Exposure of injured or ischemic muscle
• Decreased fracture healing– Potentially converting a closed to an open fracture
• Iatrogenic injury– Neuroma– Chronic venous insufficiency
Pharmacologic Treatment of Reperfusion Injury
• Following reperfusion, byproducts of anaerobic metabolism may be released causing local and systemic effects
• Administration before reperfusion– Mannitol
• Free radical scavenging– Heparin
• Anti-coagulant• Anti-inflammatory
• May be contraindicated in acute trauma
Issues Concerning Surgical Order
• The order of surgical repair in penetrating injuries requiring both vascular repair and orthopaedic fixation is controversial:– Delayed revascularization until after
orthopaedic stabilization may adversely effect limb salvage
– Fractures instability or subsequent orthopaedic stabilization may disrupt a vascular repair
Surgical Order
• In general, revascularization takes precedence over definitive orthopaedic fixation
• In cases with gross fracture instability• a temporary vascular shunt can be placed and vascular
repair deferred until after orthopaedic fixation• If the ischemia time is short, consideration can be given to
application of a provisional unilateral external fixator prior to revascularization
Temporary Vascular Shunt
Definitive Vascular Repair
Definitive Fixation
• Definitive orthopaedic fixation should be internal in most cases
• Consider external fixation for:– Pediatric fractures– Extensive soft-tissue injuries– Contaminated wounds– Hemodynamically unstable patients
Penetrating Superficial Femoral Artery Injury with Femur Fracture
Summary
• The treatment of fractures or dislocations with vascular injury requires close coordination between the orthopaedic surgeon and the vascular or general surgeon to facilitate optimal limb outcome.
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