Acute Limb Ischemia Management (ESVS 2020)

Algorithm Steps

1. ▶

   Start

   Suspected Acute Limb Ischemia

   Sudden decrease in limb perfusion threatening viability

   1. ●

      Action

      Immediate Clinical Assessment

      The 6 Ps of Acute Limb Ischemia

      • Pain - sudden, severe
      • Pulselessness - absent distal pulses
      • Pallor - pale/mottled skin
      • Perishing cold - cold to touch
      • Paresthesia - sensory loss
      • Paralysis - motor loss (late, ominous)
      1. ●

         Action

         Immediate Anticoagulation

         UFH unless contraindicated

         • UFH 5000 IU bolus IV
         • Then infusion targeting aPTT 2-2.5x control
         • Prevents clot propagation
         • Continue until definitive treatment
         • DO NOT DELAY for imaging
         1. ◆

            Decision

            Rutherford Classification

            Determines treatment urgency

            • I: Viable - no immediate threat
            • IIa: Marginally threatened - salvageable if treated promptly
            • IIb: Immediately threatened - salvageable with immediate revascularization
            • III: Irreversible - major tissue loss or permanent nerve damage inevitable
            1. ●

               Action

               Class I: Viable

               No sensory or motor deficit

               • Capillary refill intact
               • Audible arterial Doppler signals
               • No immediate limb threat
               • Time for full evaluation
               • Anticoagulate and investigate
               1. ◆

                  Decision

                  Etiology Assessment

                  Embolic vs Thrombotic

                  • Embolic: AF, recent MI, prosthetic valve, sudden onset, no claudication hx
                  • Thrombotic: PAD history, claudication, prior intervention, subacute
                  • Affects treatment strategy and prognosis
                  1. ●

                     Action

                     Surgical Embolectomy

                     First-line for embolic ALI

                     • Fogarty balloon catheter embolectomy
                     • Groin or popliteal approach
                     • Local or general anesthesia
                     • Intraoperative angiography/completion imaging
                     • Consider fasciotomy prophylactically
                     1. ●

                        Action

                        Post-Revascularization Care

                        Critical monitoring period

                        • Monitor for compartment syndrome (4 compartment pressures >30mmHg = fasciotomy)
                        • Reperfusion injury: rhabdomyolysis, hyperkalemia, acidosis
                        • Continue anticoagulation
                        • Serial pulse checks/ABI
                        • Hydration to prevent AKI from myoglobin
                        1. ●

                           Action

                           Secondary Prevention

                           Address underlying cause

                           • Embolic: anticoagulation, echo, AF management
                           • Thrombotic: antiplatelet, statin, risk factor modification
                           • Hypercoagulable workup if indicated
                           • Smoking cessation
                           • Surveillance imaging
                           1. ✓

                              Outcome

                              Limb Salvage

                              Successful revascularization - 75-90% for Class I-IIa, lower for IIb

                        2. ✓

                           Outcome

                           Amputation

                           10-30% overall; 100% for Class III; consider quality of life

                  2. ●

                     Action

                     Endovascular Treatment

                     CDT or mechanical thrombectomy

                     • Catheter-directed thrombolysis (CDT)
                     • tPA or urokinase infusion
                     • Mechanical thrombectomy devices
                     • Better for thrombotic/graft occlusions
                     • Requires ICU monitoring during CDT
                  3. ●

                     Action

                     Open Surgical Bypass

                     For thrombosis with extensive disease

                     • Bypass with vein or prosthetic graft
                     • Combined with thrombectomy
                     • Indicated for native vessel thrombosis
                     • May combine with endovascular
                     • Higher complexity, longer recovery
            2. ●

               Action

               Class IIa: Marginally Threatened

               Minimal sensory loss (toes)

               • No muscle weakness
               • Inaudible arterial Doppler
               • Venous Doppler audible
               • Salvageable if treated promptly
               • Hours to intervene
            3. ⚠

               Warning

               Class IIb: Immediately Threatened

               Rest pain, sensory loss beyond toes, mild-moderate motor deficit

               • Inaudible arterial Doppler
               • Venous Doppler often inaudible
               • REQUIRES IMMEDIATE REVASCULARIZATION
               • Target <6 hours to revascularization
               • Highest priority
            4. ⚠

               Warning

               Class III: Irreversible

               Profound sensory and motor loss, muscle rigor

               • Anesthetic limb
               • Complete paralysis
               • No Doppler signals
               • Skin marbling, muscle rigidity
               • Revascularization contraindicated - primary amputation
               1. ⚠

                  Warning

                  Primary Amputation

                  For irreversible ischemia (Class III)

                  • Indicated when limb non-viable
                  • Prevents reperfusion syndrome/MODS
                  • Level determined by tissue viability
                  • Life over limb in unstable patients
                  • Early palliative care consultation
      2. ●

         Action

         Imaging (If Time Permits)

         CTA preferred - do not delay treatment

         • CTA: gold standard for anatomy
         • Duplex if CTA unavailable
         • Shows level of occlusion
         • Identifies embolic vs thrombotic cause
         • Skip if Rutherford IIb - go to OR