The Vascular Lab and the Angiographic Assessment of PAD The Vascular Lab and the Angiographic Assessment of PAD John C. Lantis II, MD John C. Lantis II, MD Assistant Professor of Surgery – Columbia Assistant Professor of Surgery – Columbia Director of Clinical Research Director of Clinical Research St Lukes-Roosevelt Hospital St Lukes-Roosevelt Hospital

The Questions Does the patient have enough blood flow to heal their wound / or the intervention ? Does the patient have enough blood flow to heal their wound / or the intervention ? Does the patient have PAD, and should I be helping them to find coordinated care ? Does the patient have PAD, and should I be helping them to find coordinated care ? Is the patients circulation compromised to the point that I am highly concerned about tissue loss ? Is the patients circulation compromised to the point that I am highly concerned about tissue loss ?

The Answers! (Obviously) A good physical exam (Obviously) A good physical exam Physiologic testing Physiologic testing Ankle brachial indexAnkle brachial index Pulse volume recordingPulse volume recording Duplex/MRI – NOVADuplex/MRI – NOVA TCPO2 (Transcutaneous Oxygen Tension)TCPO2 (Transcutaneous Oxygen Tension) Anatomic testing Anatomic testing DuplexDuplex MRAMRA AngiogramAngiogram CTACTA

The Ankle Brachial Index Measurement of segmental leg pressure compared to the highest brachial artery pressure Measurement of segmental leg pressure compared to the highest brachial artery pressure Can be done at the bedsideCan be done at the bedside Requires little equipmentRequires little equipment Helps determine level of diseaseHelps determine level of disease

The ankle brachial Index Prognostic capabilities Prognostic capabilities Forefoot amputations are likely to heal, if the ankle pressure is > 70 mmHg, or if the ABI > 0.45Forefoot amputations are likely to heal, if the ankle pressure is > 70 mmHg, or if the ABI > 0.45 Toe amputations are likely to heal with ankle pressures of > 35 mmHg or toe pressures > 55 mmHgToe amputations are likely to heal with ankle pressures of > 35 mmHg or toe pressures > 55 mmHg Limitations Limitations Ankle pressures can be artificially inflated in patients with diabetes mellitus and ESRDAnkle pressures can be artificially inflated in patients with diabetes mellitus and ESRD Toe pressures are therefore relied uponToe pressures are therefore relied upon Pressure less than 50 mm Hg and a toe-to-arm ratio of less than 0.6 is indicative of ischemic arterial disease Pressure less than 50 mm Hg and a toe-to-arm ratio of less than 0.6 is indicative of ischemic arterial disease Foot lesions usually heal if toe pressures exceed 30 mmHG in non- diabetic patients and 55 mmHG in diabetic patients Foot lesions usually heal if toe pressures exceed 30 mmHG in non- diabetic patients and 55 mmHG in diabetic patients Ipsilateral ankle to toe pressures can be used to assess for obstructive pedal vascular disease Ipsilateral ankle to toe pressures can be used to assess for obstructive pedal vascular disease AVG 0.65 in normalsAVG 0.65 in normals AVG 0.23 in patients with rest pain of tissue lossAVG 0.23 in patients with rest pain of tissue loss

Pulse Volume Recordings More sensitive and more specific More sensitive and more specific Probably the bread and butter physiologic test Probably the bread and butter physiologic test Will give good guidance to the level and severity of disease Will give good guidance to the level and severity of disease

Pulse Volume Recordings (with ABI and exercise) Treadmill walking test Treadmill walking test Walking at 1.8 mphWalking at 1.8 mph 10 % incline10 % incline Uncovers more subtle lesionsUncovers more subtle lesions Especially proximal lesions in the iliac and SFA vessels Especially proximal lesions in the iliac and SFA vessels A fall in the ABI of 0.2 or a recovery to baseline pressure that is greater than 1 minute is significant A fall in the ABI of 0.2 or a recovery to baseline pressure that is greater than 1 minute is significant

Categories of Chronic Limb Ischemia Clinical Description Clinical Description Normal AsymptomaticNormal Asymptomatic Mild ClaudicationMild Claudication (ABI - < 0.7) (ABI - < 0.7) Moderate ClaudicationModerate Claudication Severe claudicationSevere claudication Rest PainRest Pain (ABI - < 0.4) (ABI - < 0.4) Minor Tissue LossMinor Tissue Loss Major Tissue LossMajor Tissue Loss Pressure Criteria Pressure Criteria Normal Treadmill test Completes test, ankle pressure drops > 20 mmHg, absolute ankle pressure > 50 mmHg Between mild and severe Cannot complete treadmill test and ankle pressure after exercise < 50 mm Hg Resting ankle pressure < 60 mmHG or toe pressure < 40 mmHG Resting ankle pressure less than 40 mmHg or toe pressure less than 30 mmHg Same as minor

Duplex Ultrasound (Combination of B mode imaging and doppler velocity criteria) Doppler waveform analysis of the femoral, popliteal and tibial vessels can be carried out Doppler waveform analysis of the femoral, popliteal and tibial vessels can be carried out Waveforms are evaluated similarly to the PVR tracings Waveforms are evaluated similarly to the PVR tracings More accurate at localizing disease than PVRs More accurate at localizing disease than PVRs Very labor intensive Very labor intensive

Transcutaneous Partial pressure of Oxygen Transcutaneous oxygen (tcPO 2) Transcutaneous oxygen (tcPO 2) Reflects the metabolic state of the target tissueReflects the metabolic state of the target tissue Best for severe ischemiaBest for severe ischemia Heated Clark electrode (very tech dependent, hard to reproduce)Heated Clark electrode (very tech dependent, hard to reproduce) < 20 mmHg – healing failure< 20 mmHg – healing failure > 40 mmHg – healing success> 40 mmHg – healing success Elevate limb > 30 0 /3 min – drop > 15 mmHg – healing failureElevate limb > 30 0 /3 min – drop > 15 mmHg – healing failure

Other Methods of Assessing Blood Supply Laser Doppler Velocimetry Laser Doppler Velocimetry A relative index of cutaneous blood flowA relative index of cutaneous blood flow With ischemia pulse waves are attenuated, mean velocities are decreasedWith ischemia pulse waves are attenuated, mean velocities are decreased If mean velocity is > 40 millivolts (mV) and pulse wave amplitude is > 4 mV – associated with healingIf mean velocity is > 40 millivolts (mV) and pulse wave amplitude is > 4 mV – associated with healing NOVA NOVA Non-invasive Optimal Vessel Analysis (NOVA) a non- invasive Magnetic Resonance Imaging (MRI) techniqueNon-invasive Optimal Vessel Analysis (NOVA) a non- invasive Magnetic Resonance Imaging (MRI) technique NOVA provides actual milliliter/minute blood flow data using specialized software analysis of standard MRI phase contrast imagingNOVA provides actual milliliter/minute blood flow data using specialized software analysis of standard MRI phase contrast imaging InvestigationalInvestigational

Back to the Questions…. Does the patient have enough blood flow to heal their wound / or the intervention ? NO Does the patient have enough blood flow to heal their wound / or the intervention ? NO Does the patient have PAD, and should I be helping them to find coordinated care ? YES Does the patient have PAD, and should I be helping them to find coordinated care ? YES Is the patients circulation compromised to the point that I am highly concerned about tissue loss ? YES Is the patients circulation compromised to the point that I am highly concerned about tissue loss ? YES

Leads to the next two questions… Where is the patients lesion? Where is the patients lesion? Segmental PressuresSegmental Pressures Segmental PVRsSegmental PVRs Long leg duplexLong leg duplex Can I get this patient revascularized? Can I get this patient revascularized? What type of lesion?What type of lesion? How many and where?How many and where?

MRA Non nephrotoxic contrast Non nephrotoxic contrast No arterial puncture No arterial puncture However, claustrophobia limited However, claustrophobia limited Sensitivity and specificity to level of disease 80-85% Sensitivity and specificity to level of disease 80-85% Approximately 85 % concordance with Angiography Approximately 85 % concordance with Angiography

MRA

Angiography Usually nephrotoxic dye Usually nephrotoxic dye Arterial puncture Arterial puncture Done with sedation (few issues with claustrophobia) Done with sedation (few issues with claustrophobia) Able to intervene at time of procedure Able to intervene at time of procedure With subtraction capabilities probably able to see post-occluded vessels as well as MRA With subtraction capabilities probably able to see post-occluded vessels as well as MRA

Angiography

CT Angiogram Approaching MRAs capabilities Approaching MRAs capabilities Relatively large nephrotoxic dye load Relatively large nephrotoxic dye load No arterial puncture No arterial puncture Minimal claustrophobia issues Minimal claustrophobia issues Distal vessel resolution still machine and center dependent Distal vessel resolution still machine and center dependent

CT Angiogram

A day in the life…. A patient limps in… A patient limps in… No palpable pulse… No palpable pulse… Small amount of tissue loss Small amount of tissue loss ABI/PVRs are obtained ABI/PVRs are obtained ….Obtain toe NIFs.. ….Obtain toe NIFs.. Pt went onto heal.. Pt went onto heal..

Or more likely….. We have flat line tracings We have flat line tracings Which we follow with a anatomic diagnostic …. Which we follow with a anatomic diagnostic …. Which leads us to our next speakers… Which leads us to our next speakers…