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Role of Doppler in Acute Vasclar Emergencies
Role of Doppler in Acute Vascular EmergenciesDr Rupa Ananthasivan DMRD, DNB, FRCRConsultant Radiologist, Manipal Hospital, Bangalore.
Vascular EmergenciesPrompt diagnoses
Accurate Diagnoses
Timely Intervention
Quick Decision Making-Surgical vs Non-surgical
Tools AvailableUltrasound with Doppler
CT Angiography
MR Angiography
DSA
Intravascular USG
AdvantagesReadily Available
Portable
Speed
Temporal Resolution
Spatial Resolution
DisadvantagesAcoustic Impedance-Air, Bone, Soft tissue, Bowel, tissue oedema,
Field of View
Operator Dependence
Dos and Donts !!!
Do NO Harm !!!
Be Prepared.
Be Meticulous but quick.
Know your Patient and your machine .
Acute Vascular Emergencies Ruptured Aortic AneurysmAcute Carotid ThrombosesCarotid and Vertebral dissectionPseudo-AneurysmAcute Limb IschemiaGraft Failure
Ruptured Aortic AneurysmFatal if untreated. 50 % may not reach hospital aliveSurgery=30-65 % survival rateClassical Triad- Back Pain, Hypotention, Pulsatile Abdominal Mass- 50%Timely Intervention is the key
Propensity to RuptureF > M
> 6 cm
Increase in size > 5 mm / year (vs 2-3 mm/yr)
Ruptured Aortic AneurysmSensitivity= 98 %Specificity=95 %
( Setting of Abdominal Pain and Haemodynamic Instability)
FindingsCrescent of Intramural Hemorrhage
Para- Aortic Haematoma
Retroperitoneal Haematoma
Haemoperitoeum
Acute Carotid ThrombosisComplication of endarterectomy/ stenting
Acute progression of Carotid stenosis Culprit lesion in an acute stroke
Acute Carotid ThrombosisThrombus is heterogenously echogenic/ or very hypo-echoic
Calibre of vessel is normal or expanded
Pulsations in vessel wall but NO FLOW
Swirling, sludge like flow in Carotid bulb
Thump Flow
Acute Carotid Thrombosis-Thump flow proximally
No flow in the ICA
Low resistance flow in the ECA
Free Floating ThrombusBroad Base towards vessel wall
Tongue like projection
Oscillation with blood flow
Carotid DissectionDue to hemorrhage into the intima with extension into sub-intimal and sub-adventitial layers
Type A Dissection of Aortic Arch
Carotid DissectionEhler-Danlos SyndromeFMDIdiopathicTrauma- Hyper-extension, PenetratingIatrogenic-Following Catheterization
PresentationOften delayedNeck pain, headacheTinnitusFocal neurological defectsHorners SyndromeBlindness
Dissections20% strokes in young patients
2.5% strokes in older patients
Carotid DissectionIntra-cranial- Rare-75% mortality -20-30 yrs
Extra-cranial- Subtle Symptoms-40yrs Commonly - proximal ICA just distal to bifurcation
Extra- cranial Carotid DissectionPatent Carotid BifurcationTapering of the proximal ICADistal ICA stenosis /occlusionIntimal FlapThrombosed False Lumen bulging out
Carotid DissectionHigh resistance , Low velocity flow in Carotid artery
If False lumen patent low velocity to and fro flow
Carotid Dissection
Courtsey-Dr Ullas V Acharya
Vertebral DissectionOcclusion
Dampened Flow
Reverse flow
Accuracy Cervical Carotid artery=70 %
Vertebral Artery=75-86%
Pseudo AneurysmContained Rupture of a blood VesselAbsence of three layers
Causes Iatrogenic- Catheterization, Post-Surgical following Anastomosis, Arterial RepairPenetrating Trauma
Femoral Pseudo-aneurymO.2 % of diagnostic angios
8% 0f Interventional procedures
CFA > EIA> SFA> DFA
Femoral Pseudo-AneurysmIncidence=7-9 %
> Size of Catheter, >Length of procedure, >Use of anti-coagulants, >Obesity, >Hypertension
Femoral Pseudo-aneurysmOften 1-10 days post-procedureSwelling in GroinPulsatile massThrill
Femoral PseudoaneurysmBubble like Anechoic /hypoechoic structure attached to artery
Cylindrical neck along needle track
Bubble measures 1-3 cms
Neck variable length and width
Femoral PseudoaneurysmSwirling pattern within pseudo-aneurysm-----Yin-Yang
To and Fro flow in the neck
Rarely only neck show flow
TreatmentUSG guided compression- Upto 75% success > Ihr compression > painful
Thrombin Injection-99% success 0.5-1ml 0f 1000 IU/ml
Inadvertent injection into artery/vein very rare
HematomaNatural Outcome of Vascular DisruptionDue to poor CompressionEcchymosis and DiscomfortRarely large compressing the artery and nerve rootsRetroperitoneal and pelvic extention, Compartment syndrome
HaemotomaInitially Echogenic / hypo-echoic well/ill defined area
Later becomes more well-defined and anechoic
Initial scan exact measurements and even skin marking
Acute Limb IschemiaEmbolic- Heart, Aorta, Iliac arteries, Aneurysm
Thrombosis over an existing plaque
Symptom onset is usually rapid-severe claudication, rest pain, sensory loss and colour change
Depends upon collaterals
Acute InterventionsLimb Saving-Embolectomy, Bypass, Thrombolysis
Life Saving- Amputation
Acute Limb IschemiaGray Scale
Colour Doppler
Spectral Tracing
Acute Limb IschemiaCase 1--- Gangrene left Foot
Case 2- Acute Pain Right hand, Impending Gangrene
Case 3- Gangrene right Thumb
Left Superficial Femoral Artery-1
Brachial Artery Case 2
Acute Limb IschemiaAcute Thrombosis - hetero-echoic/ hypoechoic
Expansion of Vessel
Retrograde Propagation
Use Accompanying veins to track artey
Identify reconstituted area
Acute Limb IschaemiaUpstream- High Resistance, Biphasic, Reversed Diastolic
Downstream-Monophasic, Low resistance, Decreased Velocity
70
Case 2- Impending Gangrene-Right Hand
Case 2
Case 1- Gangrene Left Foot
Case 3- Gangrene Left Thumb
Case 1- Left Foot GangreneLeg arteries
Case 2- Impending Gangrene-Right Hand
Case 3- Gangrene Left Thumb
DiagnosesCase 1- Superficial Femoral artery occlusion due to atherosclerosis with significant small vessel disease
Case 2- Acute Distal Subclavian Artery Occlusion
Case 3-Significant Radial Artery Compromise
Case 2- Acute Subclavian Occlusion
Failed Inguino Bypass Graft> 1 month ---------Surgical technique
1month-2 years---Fibrio-intimal Hyperplasia
> 2 years-------------Atherosclerosis
Bypass Graft FailureGraft thrombosis
Absent Flow
Poor flow in run off vessels
Impending FailureLow flow velocity within the graft
Average velocity < 45 cm/sec
Interval decrease in ankle- brachial index
Be Prepared to be unprepared !!!!-Alert-Quick-Accurate-CalmThe Eyes do not see what the mind does not know !!!!
AcknowlegementsDr Pramesh Reddy
Mr. Mahesh Mahadev
Carotid StenosisCandidates for Acute Carotid Endarterectomy / Acute Carotid Stenting
Cresendo TIAStroke In EvaluationFluctuating defficietsFree floating thrombosis
Intra-operative USGIntimal flapsUlcerative plaquesRetained Thrombi
Acute Limb Ischaemia
? Segmental Pressure GradientsEntire limb artery Examination
AVF (Graft ) Thrombosis
Loss of thrill
Inability to dialyze
Swelling
Usually Venous portion
Other ComplicationsA-V Shunting through unligated veins
Anastomotic Pseudoaneurysm
Perigraft Abcess