Vascular Investigations Prof.Mussaad.S.Al Salmaan. FRCSC,FACS Professor & Consultant Vascular Surgeon. Dean College of Medicine. Dean College of Medicine

Vascular InvestigationsVascular Investigations

Prof.Mussaad.S.Al Salmaan. FRCSC,FACSProf.Mussaad.S.Al Salmaan. FRCSC,FACS

Professor & Consultant Vascular Surgeon.Professor & Consultant Vascular Surgeon.

Dean College of Medicine.Dean College of Medicine.

KKUH & King Saud University RiyadhKKUH & King Saud University Riyadh..

Non Invasive Vascular TestsNon Invasive Vascular Tests

Utilizes instrument – Doppler Ultrasound.Utilizes instrument – Doppler Ultrasound.

Sound –longitudinal mechanical waveSound –longitudinal mechanical wave of any frequency.of any frequency.

Audible Sound rangeAudible Sound range 20-20,000 cycles/sec.20-20,000 cycles/sec. 20Hz-20kHz20Hz-20kHz

Ultrasound-’Ultra’ means ‘Above’ human Ultrasound-’Ultra’ means ‘Above’ human hearing - >20,000 cyc/sec(20kHz).hearing - >20,000 cyc/sec(20kHz).

Diagnostic Ultrasound –2MHz-12MHzDiagnostic Ultrasound –2MHz-12MHz

(2million-12million cyc/sec).(2million-12million cyc/sec).

Doppler ultrasound-based on Doppler ultrasound-based on principle of Doppler effect/shift.principle of Doppler effect/shift.

Ultrasound interaction Ultrasound interaction with stationary object.with stationary object.

No frequency change.No frequency change.

No Doppler effect or No Doppler effect or shift.shift.

Doppler ultrasound-based on Doppler ultrasound-based on principle of Doppler effect/shiftprinciple of Doppler effect/shift

Ultrasound encounters moving objectUltrasound encounters moving object Doppler Effect or Shift occurs.Doppler Effect or Shift occurs. Change perceived frequency of Change perceived frequency of ultrasound emitted by moving object.ultrasound emitted by moving object.

In clinical practice – moving targets In clinical practice – moving targets RBC traveling with in the blood vesselRBC traveling with in the blood vessel

Source & Receiver of sound – Ultrasound Source & Receiver of sound – Ultrasound TransducerTransducer

Transducer – device converts one form of Transducer – device converts one form of energy to anotherenergy to another

Ultrasound Transducer:Ultrasound Transducer:Use piezoelectric crystals.Use piezoelectric crystals.Converts Electro potential energy (voltage) into Converts Electro potential energy (voltage) into Mechanical vibration (ultrasound) & Mechanical Mechanical vibration (ultrasound) & Mechanical vibration into Voltage.vibration into Voltage.

Types of Doppler instruments.Types of Doppler instruments.

Continuous Wave (CW)Continuous Wave (CW)

Pulsed Wave (PW)Pulsed Wave (PW)

Continuous Wave DopplerContinuous Wave Doppler

Doppler transducer Transmit continuously Doppler transducer Transmit continuously ultrasound & Receive simultaneously.ultrasound & Receive simultaneously.

Have two Piezoelectric crystals, one Transmit & Have two Piezoelectric crystals, one Transmit & other Receive.other Receive.

Continuous Wave DopplerContinuous Wave Doppler

AdvantageAdvantage

magnitude of detectable magnitude of detectable velocity – limitless.velocity – limitless.

DisadvantageDisadvantage

Not specific for depth Not specific for depth

Detects any & all vesselsDetects any & all vessels

in beam path.in beam path.

Pulse Wave DopplerPulse Wave Doppler

Single piezoelectric crystal – both transmission Single piezoelectric crystal – both transmission & reception.& reception.

Alternate pulses On & Off.Alternate pulses On & Off.

Transmit pulse – system waits – pulse travels to Transmit pulse – system waits – pulse travels to sample volume (specific area) – echo pulse sample volume (specific area) – echo pulse returns returns

Pulse Wave DopplerPulse Wave Doppler

AdvantagesAdvantages

Specific for depth & range.Specific for depth & range.

No mixture of signals like CW Doppler.No mixture of signals like CW Doppler.

DisadvantageDisadvantage

Limited maximum detectable velocityLimited maximum detectable velocity

unlimited for CW Doppler.unlimited for CW Doppler.

Angle of IncidenceAngle of Incidence

Doppler or frequency shift is what we hear & see on Doppler or frequency shift is what we hear & see on graphic display.graphic display.Affected by ‘angle of flow’ or ‘angle of incidence’Affected by ‘angle of flow’ or ‘angle of incidence’Smaller Doppler angle higher the frequency shift.Smaller Doppler angle higher the frequency shift.Optimal Doppler signals –transducer angle 45-60 Optimal Doppler signals –transducer angle 45-60 towards direction of flow.towards direction of flow.

Arterial Assessment – Doppler ultrasoundArterial Assessment – Doppler ultrasound

Audible interpretationAudible interpretation

Waveform analysisWaveform analysis

Hand held DopplerHand held Doppler

Normal Peripheral Normal Peripheral arterial Doppler signalarterial Doppler signal TRIPHASICTRIPHASIC

TRIPHASIC ARTERIAL SIGNALTRIPHASIC ARTERIAL SIGNAL

11stst sound – phase sound – phase

large, high velocity, large, high velocity, forward flow, systolic forward flow, systolic component.component.

22ndnd sound – phase sound – phase

smaller reverse flow smaller reverse flow early diastoleearly diastole

33rdrd sound – phase sound – phase

smaller forward flow smaller forward flow late diastolelate diastole

Audible interpretation & Wave form analysisAudible interpretation & Wave form analysis

PVR ( Pulse Volume Recording)PVR ( Pulse Volume Recording)

Normal PVRNormal PVR

1.Brisk systolic upstroke 1.Brisk systolic upstroke Anacrotic limb.Anacrotic limb.

2.Sharp systolic peak.2.Sharp systolic peak.

3.Gradual down stroke3.Gradual down stroke

Catacrotic limbCatacrotic limb

4.Dicrotic notch-reflective 4.Dicrotic notch-reflective wave-during diastole wave-during diastole normal peripheral normal peripheral resistanceresistance

PVR ( Pulse Volume Recording)PVR ( Pulse Volume Recording)

Arterial Pressure measurementsArterial Pressure measurements

Peripheral arterial occlusive diseasePeripheral arterial occlusive disease..

Sequence of pressure measurement tests.Sequence of pressure measurement tests.

Systolic Brachial & Ankle pressure at restSystolic Brachial & Ankle pressure at rest

Calculation of ABICalculation of ABI

Toe pressure-non compressible tibial artsToe pressure-non compressible tibial arts

Arterial Pressure measurementsArterial Pressure measurements

Sequence of pressure measurement tests cotnd,Sequence of pressure measurement tests cotnd,

Segmental pressure & waveforms – low Segmental pressure & waveforms – low ABI.ABI.

Stress testing – severity of claudicationStress testing – severity of claudication

& to rule out& to rule out

pseudoclaudication pseudoclaudication

Contraindication to pressure measurementsContraindication to pressure measurements

Acute DVTAcute DVT

Bandages & castsBandages & casts

UlcerationUlceration

TraumaTrauma

Surgical siteSurgical site

Ankle Brachial Index (ABI)Ankle Brachial Index (ABI)

Patient supine arms at sidesPatient supine arms at sides

Basal state(10mnts pretest rest)Basal state(10mnts pretest rest)

CW Doppler ultrasoundCW Doppler ultrasound

Appropriate size pressure cuffsAppropriate size pressure cuffs

Ankle Brachial Index (ABI)Ankle Brachial Index (ABI)

Record bilateral systolic brachial Record bilateral systolic brachial pressure & systolic Ankle pressure pressure & systolic Ankle pressure (dorslis pedis & post.tib art)(dorslis pedis & post.tib art)

Interpretation-Ratio highest ankle to Interpretation-Ratio highest ankle to brachial pressure.brachial pressure.

ABI & Relation to PAODABI & Relation to PAOD

0.97 -1.25 Normal0.97 -1.25 Normal

0.75 – 0.96 Mild PAOD0.75 – 0.96 Mild PAOD

0,50 – 0.74 Moderate0,50 – 0.74 Moderate

<0.5 Severe<0.5 Severe

<0.3 Critical<0.3 Critical

>1.5 Vessels non compressible >1.5 Vessels non compressible

Toe PressureToe Pressure

Normal toe pressure – 2/3Normal toe pressure – 2/3rdrd systolic ankle systolic ankle pressurepressure

Plethysmographic device –records Plethysmographic device –records changes in volume (used as sensor).changes in volume (used as sensor).

Toe Pressure contd,Toe Pressure contd,

Inflate cuff above 2/3Inflate cuff above 2/3rdrd of ankle pressure. of ankle pressure.

BP cuff (2.5cm) around base of toe.BP cuff (2.5cm) around base of toe.

Gradual deflate until arterial tracing Gradual deflate until arterial tracing demonstrate return of pulsatile flow – demonstrate return of pulsatile flow – recorded as systolic toe pressure.recorded as systolic toe pressure.

Segmental PressureSegmental Pressure

Drop in ABI at rest or post exerciseDrop in ABI at rest or post exercise

indicates hemodynamically significant indicates hemodynamically significant disease proximal to cuff.disease proximal to cuff.

Segmental pressure measurement – Segmental pressure measurement – localizes the diseased arterial segment. localizes the diseased arterial segment.


Pressure difference Pressure difference between two adjacent between two adjacent segments <20mm of Hgsegments <20mm of Hg


Gradient >30mmofHgGradient >30mmofHg

Hemodynamically Hemodynamically significant disease significant disease between adjacent between adjacent levels.levels.

Exercise Test (StressTest)Exercise Test (StressTest)

Thread mill stress testThread mill stress test

Reactive hyperemia stress testReactive hyperemia stress test


Assess functional limitation due to PAODAssess functional limitation due to PAOD

Differentiates PAOD – Pseudoclaudication Differentiates PAOD – Pseudoclaudication

Ex; neurogenic claudicationEx; neurogenic claudication


Resting ankle & brachial pressuresResting ankle & brachial pressures

Pressure cuffs secured in place –ankle & Pressure cuffs secured in place –ankle & arm.arm.

Walk at 2mph at 12% gradient-5mnts or Walk at 2mph at 12% gradient-5mnts or point claudication symptoms.point claudication symptoms.

Return supine position & measure ankle Return supine position & measure ankle pressure 30secs & 1mnt post exercise.pressure 30secs & 1mnt post exercise.

Measure till baseline pressure recovered. Measure till baseline pressure recovered.


Note:Note:

Duration of exercise.Duration of exercise.

Distance walked.Distance walked.

Symptoms prevented exercise.Symptoms prevented exercise.

Exercise Test (Stress Test)Exercise Test (Stress Test)

Interpretation:Interpretation:

NormalNormal :no drop in :no drop in ankle pressure.ankle pressure.

Minimal diseaseMinimal disease::

pressure returns to pressure returns to baseline in 2mntsbaseline in 2mnts


Single level diseaseSingle level disease

pressure returns to pressure returns to baseline in 3-5mnts.baseline in 3-5mnts.

Multi level diseaseMulti level disease

pressure returns to pressure returns to baseline >10mntsbaseline >10mnts

Doppler assessment of VeinsDoppler assessment of Veins

FiveFive qualities of normal qualities of normal Venous flow:Venous flow:

AA - Spontaneity - Spontaneity

BB - Phasicity - Phasicity

CC - Augmentation - Augmentation

DD - Valvular competence - Valvular competence

EE - Non pulsatility - Non pulsatility

Doppler assessment of VeinsDoppler assessment of Veins

In cases of In cases of DVTDVT

Normal five qualities ofNormal five qualities of

Venous flow are lostVenous flow are lost

Doppler assessment of Veins - DVTDoppler assessment of Veins - DVT

Ultrasound ImagingUltrasound Imaging

Imaging PrinciplesImaging Principles

Amplitude modeAmplitude mode

(A-mode)(A-mode)

method of presenting method of presenting

returning echoes of returning echoes of

US on a displayUS on a display

screenscreen

Ultrasound ImagingUltrasound Imaging

A-modeA-mode: : displayed as verticaldisplayed as vertical

deflections ordeflections or

spikes, projecting from spikes, projecting from

baseline.baseline.

Stronger echoes-higher Stronger echoes-higher amplitude signalsamplitude signals

Ultrasound ImagingUltrasound ImagingB-modeB-mode

Brightness modeBrightness modeReturning echoesReturning echoes

displayed as series of displayed as series of

dots.dots.

Position of each dotPosition of each dot

corresponds to distancecorresponds to distance

from the sound sourcefrom the sound source

Brightness correspondsBrightness corresponds

to amplitude of returningto amplitude of returning

echo – Gray scale echo – Gray scale intensity. intensity.

Duplex ScanDuplex Scan

Combination of Combination of B-modeB-mode imaging with imaging with pulsed Doppler USpulsed Doppler US – gives both – gives both anatomical & physiological information of anatomical & physiological information of vascular systemvascular system

Duplex ScanDuplex Scan

Addition of Addition of colourcolour frequency mapping – frequency mapping – Colour Duplex imagingColour Duplex imaging

Uses of colour duplex imagingUses of colour duplex imaging

Arterial:Arterial:

Identify obstructive or aneurysmal Identify obstructive or aneurysmal atherosclerotic diseaseatherosclerotic disease

peripheral arteriesperipheral arteries

carotid arteriescarotid arteries

renal & visceral arteriesrenal & visceral arteries

Surveillance of by pass grafts. Surveillance of by pass grafts.

ArterialArterial

Venous DuplexVenous Duplex

Diagnosis of DVTDiagnosis of DVT

Assessing competance of deep vein Assessing competance of deep vein valves.valves.

Superficial venous reflux & identifying Superficial venous reflux & identifying Sapheno Femoral & Popliteal Jnc refluxes.Sapheno Femoral & Popliteal Jnc refluxes.

Preoperative mapping of saphenous veinPreoperative mapping of saphenous vein

Criteria for Duplex examn. Of venous Criteria for Duplex examn. Of venous systemsystem

NormalNormal

Easily compressibleEasily compressible

Should be echo freeShould be echo free

Normal valve motionNormal valve motion

Normal Doppler Normal Doppler signalssignals

Abnormal (DVT)Abnormal (DVT)

Non compressibleNon compressible

Echogenic thrombus Echogenic thrombus in veinin vein

Incompetant valvesIncompetant valves

Absent Doppler Absent Doppler signalssignals

Venous DuplexVenous Duplex

ArteriographyArteriography

Gold Standard.Gold Standard.

Good resolution.Good resolution.

Seldinger techniqueSeldinger technique

Access –commonly femoral artery Access –commonly femoral artery

& brachial artery & brachial artery

ArteriographyArteriography

Inject iodinated contrastInject iodinated contrast

Two types of contrastTwo types of contrast

Ionic or high osmolar Ionic or high osmolar

Non ionic or low osmolarNon ionic or low osmolar

Ionic or High Osmolar ContrastIonic or High Osmolar Contrast

Water solubleWater soluble

Hypertonic, osmolality 5-10 times of blood.Hypertonic, osmolality 5-10 times of blood.

Causes discomfort at injection site.Causes discomfort at injection site.

More nephrotoxic. More nephrotoxic.

Non Ionic or Low Osmolar ContrastNon Ionic or Low Osmolar Contrast

Has same no of iodine ions ,no cationsHas same no of iodine ions ,no cations

Osmolality 1/3Osmolality 1/3rdrd of high osmolar contrast of high osmolar contrast

Still hypertonic twice that of plasma.Still hypertonic twice that of plasma.

Less nephrotoxicLess nephrotoxic

More expensiveMore expensive

ComplicationsComplications

Local:Local:

HemorrhageHemorrhage

ThrombosisThrombosis

Pseudo aneurysmPseudo aneurysm

AV fistulaAV fistula

Intimal dissectionIntimal dissection

EmbolizationEmbolization


General:General:

Renal – nephrotoxicityRenal – nephrotoxicity

Cardiac- hypertension, arrhythmias, CCF.Cardiac- hypertension, arrhythmias, CCF.

Neurological – Carotid angiogram – TIA Neurological – Carotid angiogram – TIA stroke, convultions.stroke, convultions.

Pulmonary-bronchospasm, pulm edema.Pulmonary-bronchospasm, pulm edema.


Allergic reaction to contrastAllergic reaction to contrast

Minor – nausea, vomiting, head ache, Minor – nausea, vomiting, head ache, chills, fever, itching.chills, fever, itching.

Intermediate - hypotension. urticaria, Intermediate - hypotension. urticaria, bronchospasm.bronchospasm.

Major-anaphylaxis, pul edema, laryngeal Major-anaphylaxis, pul edema, laryngeal edemaedema

VenogramVenogram

Ascending VenographyAscending Venography

Descending VenographyDescending Venography

Ascending venographyAscending venography

Relatively invasive studyRelatively invasive study

Requires painful venipuctureRequires painful venipucture

Injection of iodinated contrastInjection of iodinated contrast

Exposure to radiationExposure to radiation


IndicationIndication

High clinical suspicion of DVT with negativeHigh clinical suspicion of DVT with negative

Or equivocal non invasive vascular tests.Or equivocal non invasive vascular tests.

Gives information about anatomy & Gives information about anatomy & patency of deep veinspatency of deep veins

& locates the incompetant perforators & locates the incompetant perforators veins.veins.


Inject about 40-60 ml of contrast into Inject about 40-60 ml of contrast into superficial foot arch veins & tourniquet tied superficial foot arch veins & tourniquet tied above ankle to visualize deep veins.above ankle to visualize deep veins.

Complications: thrombophlebitisComplications: thrombophlebitis

Decending venogramDecending venogram

Indication:Indication:

To distinguish primary deep venous To distinguish primary deep venous valvular incompetance from thrombotic valvular incompetance from thrombotic disease.disease.

Identify level of deep venous reflux & Identify level of deep venous reflux & morphology of venous valves.morphology of venous valves.

Venographic categories of Deep vein refluxVenographic categories of Deep vein reflux

Grade 0 – normal valve function norefluxGrade 0 – normal valve function norefluxGrade 1 – minimal reflux confined to upperGrade 1 – minimal reflux confined to upper

thigh thigh Grade 2 – extensive reflux reach lowerGrade 2 – extensive reflux reach lower

thighthighGrade 3 – extensive reflux reach to calf Grade 3 – extensive reflux reach to calf

levellevelGrade 4 – no valvular competanceGrade 4 – no valvular competance

immediate reflux distally to calf.immediate reflux distally to calf.

LymphedemaLymphedema

Minimal invasive investigation to identify Minimal invasive investigation to identify edema of lymphatic originedema of lymphatic origin

LymphoscintigraphyLymphoscintigraphy

CT & MRICT & MRI


Isotope LymphographyIsotope Lymphography

Radiolabelled Colloid or Protein injected Radiolabelled Colloid or Protein injected 11stst web of foot web of foot

Gama Camera monitoring of tracer Gama Camera monitoring of tracer uptake.uptake.


Measurement of tracer uptake within the Measurement of tracer uptake within the lymph nodes after a defined interval – lymph nodes after a defined interval – distinguishes lymph edema from edema of distinguishes lymph edema from edema of non lymphatic origin.non lymphatic origin.

Appearance of tracer outside the main Appearance of tracer outside the main lymph routes – dermal back flow indicateslymph routes – dermal back flow indicates

Lymph reflux & proximal obstructionLymph reflux & proximal obstruction


Poor transit of isotope from injection site – Poor transit of isotope from injection site – suggest hypoplasia of lymphatics.suggest hypoplasia of lymphatics.

LymphedemaLymphedema

CT & MRICT & MRI

Honeycomb pattern in the subcutaneous Honeycomb pattern in the subcutaneous compartment, characterstic of compartment, characterstic of lymphedema lymphedema

Direct contrast X Ray lymphographyDirect contrast X Ray lymphography

LymphangiographyLymphangiographylymph vessels identified by injecting vital dyes & lymph vessels identified by injecting vital dyes & lymph vessel cannulated.lymph vessel cannulated.Lipiodol contrast directly injectedLipiodol contrast directly injectedNormal limb shows opacification of 5-15 main Normal limb shows opacification of 5-15 main lymph vessels as converge to inguinal lymph lymph vessels as converge to inguinal lymph nodes.nodes.Lymphatic obstruction-contrast refluxes into Lymphatic obstruction-contrast refluxes into dermal network – dermal backflow.dermal network – dermal backflow.

Other Modalities of Vascular InvestigationsOther Modalities of Vascular Investigations

CT, CTAngiogramCT, CTAngiogram

MRI, MRAngiogramMRI, MRAngiogram

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Vascular Investigations Prof.Mussaad.S.Al Salmaan. FRCSC,FACS Professor & Consultant Vascular Surgeon. Dean College of Medicine. Dean College of Medicine