vascular investigations prof.mussaad.s.al salmaan. frcsc,facs professor & consultant vascular...
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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
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
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.
Segmental PressureSegmental Pressure
Pressure difference Pressure difference between two adjacent between two adjacent segments <20mm of Hgsegments <20mm of Hg
Segmental PressureSegmental Pressure
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
Exercise Test (StressTest)Exercise Test (StressTest)
Assess functional limitation due to PAODAssess functional limitation due to PAOD
Differentiates PAOD – Pseudoclaudication Differentiates PAOD – Pseudoclaudication
Ex; neurogenic claudicationEx; neurogenic claudication
Exercise Test (StressTest)Exercise Test (StressTest)
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.
Exercise Test (StressTest)Exercise Test (StressTest)
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
Exercise Test (StressTest)Exercise Test (StressTest)
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
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.
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
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
ComplicationsComplications
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.
ComplicationsComplications
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
Ascending venographyAscending venography
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.
Ascending venographyAscending venography
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
LymphoscintigraphyLymphoscintigraphy
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.
LymphoscintigraphyLymphoscintigraphy
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
LymphoscintigraphyLymphoscintigraphy
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.
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