ACUTE ISCHEMIC LIMB OF PERIPHERAL ARTERIAL DISEASES.pptx

ACUTE ISCHEMIC LIMB
PERIPHERAL ARTERIAL DISEASES
DRY GANGRENE,WET GANGRENE
GANGRENE

1. ACUTE ISCHEMIC LIMB Presentator : Dr E Manisankar PG-I Moderator: Dr S Srinivas Reddy sir

2. Definition Sudden onset of pain, loss of limb perfusion & Neurological deficit up to 2 weeks after initiating event. ALI is an emergency that requires rapid, accurate clinical assessment and emergency surgical treatment. ALI typically occurs as a result of embolic arterial occlusion or trauma, but less common causes including thrombosed popliteal artery aneurysm and popliteal artery entrapment. Ischaemia beyond 6 hours is usually irreversible and results in limb loss.

3. Etiology Embolism Native Vessel Thrombosis Reconstruction Thrombosis Trauma Complications of Peripheral Aneurysm

4. Arterial Embolism The heart is the most common source of distal emboli which accounts for more than 90% of peripheral arterial embolic events. Atrial fibrillation is the most common source. Sudden cardio version results in the daily noncontractile atrial appendage regaining contractile activity which can dislodge the contained thrombus. Other cardiac sources include mural thrombus overlying a myocardial infarction or thrombus forming within a dilated left ventricular aneurysm.

5. Arterial Thrombosis Thrombosis can occur in native arteries and in arterial reconstructions. Patients with thrombosed arterial segments often have an underlying atherosclerotic lesson at the site of thrombosis or aneurysmal degeneration with mural thrombosis. So it is important to obtain a history determined risk factors for atherosclerosis and hypercoagulable status and examine the contralateral extremity for circulatory problems.

6. Assessment Confirm Diagnosis Assess the severity Identify the Underlying cause. Treat the Cause.

7. Pathogenesis

8. Clinical Features ALI Manifests with the “ Six P’s ” Pain Pallor Parathesis Paralysis Pulselessness Perishing cold - Rhabdomyolysis

9. Clinical Features The skin is initially cold and pale, but as time progresses it slowly becomes mottled. First non-fixed (blanching to pressure) and then fixed (non-blanching) indicating skin death. Neurological function deteriorates with time progressing from paresthesia to eventual complete loss of sensory and motor function causing an insensate and paralysed limb. Muscle groups are weakened and painful, manual compression of effected muscle groups may cause pain owning to ischemia induced injury – rhabdomyolysis.

10. Rutherford’s classification of ALI

11. Fontaine Classification

12. Thrombosis vs Embolism Features Thrombosis Embolism Onset Gradual Sudden H/o Claudication + - C/L Pulse Often absent Normal Source of embolus - Heart Temp Changes Low marked More marked Loss of Function Slow Rapid Angiography Diffuse disease Minimal disease Tapered & irregular cutoff Sharp cutoff Collaterals well developed Few collaterals

13. Investigations ECG to assess for myocardial infarction and/or atrial fibrillation Creatinine kinase to assess for rhabdomyolysis Renal function as rhabdomyolysis may lead to myoglobinuria and acute kidney injury CT & BT APTT

14. Imaging assessment of the affected limb’s arterial tree. Eg : DUS or CTA, if readily available and not likely to unnecessarily delay emergency treatment when indicated, like Rutherford class IIb. A similar picture will occur in the arm with a branchial embolus.

15. Treatment In the management of a patient with ischemic lower extremity, several key steps are recommended: 1. Immediate Anticoagulation : Unless there are significant contraindications, anticoagulation should be started promptly to prevent clot propagation. 2. Intravenous Fluid and Foley Catheter : Start intravenous fluid to maintain hydration and insert a Foley catheter to monitor urine output. 3. Baseline Labs: Obtain baseline laboratory tests, with particular attention to creatinine levels.

16. Treatment 4. Hypercoagulable Workup : Consider performing a hypercoagulable workup before initiating heparin if there is clinical suspicion. 5. Treatment Options : Randomized trials suggest no clear superiority between thrombolysis and surgery in terms of 30-day limb salvage or mortality. Access to each treatment option is crucial, given the time-sensitive nature of the decision-making process. 6. Preference for Surgery : National registry data from the United States indicate that surgery is used more frequently than thrombolysis, with a three- to five-fold difference.

17. 7. Catheter-Directed Thrombolytic Therapy : Some studies have investigated the role of catheter-directed thrombolytic therapy in the treatment of acute limb ischemia. These steps highlight the importance of prompt intervention, careful consideration of treatment options, and individualized management based on patient presentation and available resources.

18. Endovascular Treatment Thrombolysis is often preferred over open surgery as the first-line treatment for acute limb ischemia (ALI) due to its potential to reduce mortality and morbidity while achieving limb salvage. The advantages of thrombolytic therapy include reduced endothelial trauma and the potential for more gradual and complete clot lysis in smaller branch vessels, which are typically inaccessible by embolectomy balloons. It is hoped that the gradual clot dissolution with thrombolysis may decrease the incidence of reperfusion injury, which can occur after open surgical procedures where rapid blood flow return may lead to complications like compartment syndrome.

19. The timing of intervention is critical, as irreversible damage to muscle tissue can begin after 3 hours of ischemia and is nearly complete by 6 hours. Patients with small-vessel occlusion, who lack distal target vessels for bypass surgery, are generally poor candidates for surgery. They should be considered for thrombolysis unless contraindications are present or if the ischemia is too severe for timely clot lysis. Contraindications to thrombolysis include recent stroke, intracranial primary malignancy, brain metastases, or intracranial surgical intervention. Relative contraindications include renal insufficiency, allergy to contrast material, cardiac thrombus, diabetic retinopathy, coagulopathy, and recent arterial puncture or surgery.

20. Advancements in clot removal techniques, such as percutaneous mechanical thrombectomy and thromboaspiration , may expand the applicability of interventions for ALI, particularly for patients with contraindications to thrombolysis. Several thrombectomy devices have received FDA approval for acute lower extremity arterial thrombosis, offering standalone therapy options or combined use with thrombolytic agents for pharmacomechanical thrombectomy to enhance clot lysis and reduce treatment duration.

21. Embolectomy In cases where open surgical intervention is deemed necessary for embolectomy, the procedure typically involves prepping the abdomen, contralateral groin, and entire lower extremity in the field. A vertical incision is made in the groin to expose the common femoral artery (CFA) and its bifurcation. The location of the embolus at the femoral bifurcation is often identifiable by the presence of a palpable proximal femoral pulse that disappears distally. Surgical Treatment

22. The artery is clamped and opened transversely over the bifurcation, and a Fogarty balloon embolectomy catheter is used to extract the thrombus. Good back-bleeding and antegrade bleeding indicate successful removal of the clot. The extracted embolic material is typically sent for culture and histologic examination, and completion angiography is advised to ensure adequate clot removal before closing the artery and fully anticoagulating the patient.

23. When an embolus lodges in the popliteal artery, it can usually be extracted via a femoral incision using similar techniques. A femoral approach is preferred due to the larger diameter of the femoral artery, which reduces the risk of arterial compromise during closure of the arteriotomy. However, directing the embolectomy catheter into each of the infrapopliteal arteries may be more challenging with a femoral approach. Fluoroscopic imaging and an over-the-wire thrombectomy catheter can help overcome this difficulty, or a separate incision may be necessary to expose the popliteal bifurcation for complete thrombectomy.

24. Bypass Graft Thromectomy Bypass thrombectomy is more likely to succeed with prosthetic bypasses, whereas bypass graft revision or replacement is often more appropriate for acute vein graft failures. Vein grafts are less likely to respond to thrombolysis and typically require some form of revision, such as valve lysis, interposition, or extension. Thrombectomy of autogenous (natural) grafts is prone to failure unless an anatomic cause for failure, such as a retained valve or unligated side branch, is identified and corrected.

25. In cases where reperfusion injury or compartment syndrome is a concern, performing a fasciotomy may be necessary to alleviate pressure and prevent complications. This consideration is important in managing the aftermath of successful revascularization procedures.

26. Complications Interventionalists are cautious about using thrombolysis in patients over 80 due to complications. Patients treated for acute ischemia face two major complications post-revascularization: reperfusion and compartment syndromes. Other procedure-related complications include arterial rethrombosis , recurrent embolization, and arterial injuries from catheter manipulations.

27. Reperfusion effects vary based on ischemia severity. Some may experience the full-blown "reperfusion syndrome," while others may have minimal effects if reperfused timely. Patients with acute limb ischemia (ALI) often have severe underlying cardiac disease, making them intolerant to ischemic periods. Complications can occur post-revascularization of the lower extremity and can lead to recurrent thrombosis.

28. Compartment Syndrome Compartment syndrome occurs after prolonged ischemia followed by reperfusion, leading to fluid leakage into muscle interstitial space within a fascial envelope. Elevated compartment pressure halts nutrient flow, causing progressive ischemia despite peripheral pulses. Symptoms include excessive pain, pain on passive stretching, and sensory loss due to nerve compression.

29. The anterior compartment in the leg is commonly affected, with numbness between the first and second toes. Compartment pressure is measured via arterial line insertion, with pressures over 20 mmHg potentially requiring fasciotomy. Fasciotomy involves medial and lateral incisions to relieve compartment pressure.

30. Rhabdomyolysis occurs in 20% of cases, leading to myoglobin precipitation in kidney tubules and acute tubular necrosis. Treatment includes alkalinization of urine, saline diuresis, and removal of the source of dead muscle releasing myoglobin.

31. Thank You