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