Acute Ischemia Of Lower Limb (AILL)

1. Acute Ischemia Of Lower Limb(AILL) • Aetiology 1. Embolisation most common cause heart as a source - 70 %, Atrial Fibrillation, AMI with mural thrombus 2. Acute thrombosis superimposed upon stenosis 3. Popliteal Aneurysm Dr. Rajdeep Agrawal

2. Acute Ischemia Of Lower Limb • The extent of ischemia & final outcome depends upon 1. Size & location of clot 2. Extent of collateral circulation 3. Time between onset of occlusion & treatment Dr. Rajdeep Agrawal

3. Clinical Features • Characterized by 5 “P”s 1. Pain - sudden onset 2. Pallor- waxy 3. Parasthesia – numbness 4. Pulselessness 5. Paralysis Dr. Rajdeep Agrawal

4. Therapeutic Strategies in Acute Ischemia • Most common vascular emergency 1. Intra arterial thrombolysis 2. Thrombo-aspiration with catheter 3. Mechanical thrombolysis 4. Surgical embolectomy – Fogarty catheter Dr. Rajdeep Agrawal

5. Peripheral Intra-arterial Thrombolysis (PIAT) • Rapidly restores blood flow to ischemic limb & identifies underlying lesions for percutaneous or surgical intervention • Catheter directed local delivery of thrombolytic agents directly at the site of thrombosis is significantly more effective than systemic thrombolysis & is associated with lower bleeding complications Dr. Rajdeep Agrawal

6. Thrombolytic Agents • Streptokinase • Urokinase • Recombinant human tissue type plasminogen activator (rtpA, alteplase) In recent years UK & rtpA have largely superceded & replaced SK as preferred agent Dr. Rajdeep Agrawal

7. Peripheral Intra-arterial Thrombolysis (PIAT) PIAT – Common procedure • Angiography is done • Thrombus is located • Multiple end hole catheter is advanced to the upper limit of the thrombus • One of the infusion methods shown next is then used Dr. Rajdeep Agrawal

8. PIAT– Infusion Methods • Stepwise infusion Done by stepwise advancement of infusion catheter as thrombus dissolves • Graded infusion( McNamara’sprotocol) gradual tapering of infusion rate • Continuous infusion • Pulse spray technique Dr. Rajdeep Agrawal

9. PIAT--McNamara’s Protocol • UK 4000 units/min x 2hrs 2000 units/min x next 2hrs 1000 units/min x next 4-24 hrs or until the lysis is completed Systemic heparin continued during PIAT And till definite endovascular or surgical Rx of underlying lesion is done Dr. Rajdeep Agrawal

10. PIAT--McNamara’s Protocol • Complete lysis is considered if > 75% of the clot dissolves • Initial reestablishment of flow takes on an 3.3 hrs avg. complete clot lysis up to 13hrs avg Systemic Heparin is continued through this period Dr. Rajdeep Agrawal

11. Predictors Of Successful Thrombolysis • Easy traversability of clot with non-hydrophilic guide wire 0.035” • Significant lysis within 2hrs Dr. Rajdeep Agrawal

12. Thrombolysis-Contraindications • Absolute 1. Recent Cerebro Vascular Accident, neurosurgery, intracranial trauma, within the last 3 months 2. Active bleeding diathesis 3. Recent GI bleed (< 10days) 4. Irreversible ischemia Dr. Rajdeep Agrawal

13. Thrombolysis-Contraindications • Relative 1. Cardiopulmonary resuscitation, major nonvascular surgery, trauma within last 10 days 2. Uncontrolled HT systolic > 180 diastolic >110 3. Puncture of non compressible vessel 4. Intracranial tumor, diabetic proliferative retinopathy, bacterial endocarditis, pregnancy Dr. Rajdeep Agrawal

14. PIAT -- Complications • Significant hemorrhage 1% • Distal Embolisation Dr. Rajdeep Agrawal

15. Post PIAT Management • Underlying flow limiting lesion is present in more than 70% cases & surgery or PTA can be performed immediately after thrombolysis with no additional risk of hemorrhage • No underlying lesion -- anticoagulation Dr. Rajdeep Agrawal

16. Treatment of Acute Occlusion • Embolectomy - Using Fogarty’s catheter -> Catheter passed beyond emblous, balloon inflated & pulled back till blood comes • Direct Embolectomy - Artery exposed, transverse incision, clot removed. • Intra-arterial Thrombolysis - TPA preferred. Arteriography done and a catheter embedded in clot - Thrombolytic agent infused over several hrs Dr. Rajdeep Agrawal

17. Surgical Embolectomy • Relatively simple procedure • Done under LA, small incision in the groin, using Fogarty’s cath. • Problems 1. Blind procedure, can be traumatic 2. Not successful in 10 – 30% cases 3. Inefficient in multistenosed artery 4. Complete removal of thrombus difficult in leg arteries Dr. Rajdeep Agrawal

18. Post PTA MX • Antiplatelet agents • LMW Heparin X 7 – 10 D • IV / oral Trental • Statins • Aggressive control of risk factors Dr. Rajdeep Agrawal

19. Newer Techniques Of Angioplasty • Atherectomy • Directional • Percutaneous Rotational • TEC • LASER • Stent Dr. Rajdeep Agrawal

20. Directional Atherectomy • It excises the atheromatous plaque material into very fine slices which can be retrieved outside body Dr. Rajdeep Agrawal

21. Percutaneous Rotational Atherectomy (Rotablator) Dr. Rajdeep Agrawal

22. LASER • A LASER produces an intense beam of light in uniform wavelength that can be precisely focused to deliver high energy levels to a small area • It converts solid plaque to gas which is soluble in blood Dr. Rajdeep Agrawal

23. Stent • An expandable metallic helical device which is permanently implanted in the artery. • Mechanism • The prosthesis acts as a scaffold to hold the artery open • Prevents recoil of the vessel • Reduces Restenosis Dr. Rajdeep Agrawal

24. Lower Limb Ischemia - Approach to therapy • Risk factor management * Abstinence from smoking * Control of diabetes * Control of hyperlipidemia Dr. Rajdeep Agrawal

25. Lower Limb Ischemia - Approach to therapy • Risk factor management *Weight reduction • Control of hypertension, CHF, CRF • Chronic anticoagulation oral with judicious use of PT PI measurements Dr. Rajdeep Agrawal

26. Lower Limb Ischemia - Role of Drugs • Pentoxyfylline – not useful • Antiplatelet Agents • Prostaglandins • Vasodilators Dr. Rajdeep Agrawal