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

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

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

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

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

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Urokinase Recombinant human tissue type plasminogen activator (rtpA, alteplase) In recent years UK & rtpA have largely superceded & replaced SK as preferred agent Dr.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

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

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

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

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

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

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

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

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

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

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

Surgical Embolectomy Problems 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

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

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

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

Percutaneous Rotational Atherectomy (Rotablator) Dr. Rajdeep Agrawal

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

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

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

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

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