chronic lower limb ischemia
DESCRIPTION
A complete seminar on chronic lower limb ischemiaTRANSCRIPT
CHRONIC LOWER LIMB ISCHEMIA
Dr Minhajuddin KhurramAl-Ameen Medical College
Bijapur (Karnataka)India
DefinitionPeripheral areterial occlusive disease (PAOD/PAD/PVD) refers to the obstruction or detoriation of ateries other than those supplying the heart and within the brain
Epidemiology & Risk factors
Impairment of circulation Incidence increases with age
0.3%/yr (40 to 55yrs) to 1%/yr (after 75yrs) Quality of life/cost of treatment Non whites> whites Male gender Obesity
Epidemiology & Risk factors
Black (hispanic) Increasing age Smoking Hypertension Dyslipidemia Hypercoaguble states Renal insufficiency DM
Younger>aged
Epidemiology & Risk factors
Family history of vascular disease or stroke/ heart attack
In study C-reactive protein Homocysteine
Anatomy
Micro Anatomy
Intima Internal elastic membrane
Media Composed of smooth m/s, collagen, elastin and
preteoglycans Blood suply:
Internal half: Direct diffusion External half: vasa vasorum
External elastic membrane Adventitia
• Fibroblasts and collagen
Micro Anatomy
Acute vs Chronic Occlusion Acute
Sudden occlusion of an artery No time for collateral openings Poikilothermia, Pain, Pulseless, Pallor,
Parasthesia and Paralysis Chronic
No sudden obstruction Gradual narrowing of lumen Enough time for collaterals to develop More tolerant to prolonged ischemia
Causes of Chronic Occlusion
Atherosclerosis {lower limb}
TAO (Buerger’s Disease) {lower limb}
Infective
Vasculitis syndromes
Atherosclerosis
Atherosclerosis Atherosclerosis =
Athero + sclerois Plaque composed of
smooth m/s, lipids, connective tissue and macrophages
Atherosclerosis Brief pathophysiology
Lipid deposition calcificationerosive areas and
ulceration prothrombotic cell activity plaque
lipid core becomes necrotic covered by FIBROUS
CAP rupture, perceived as injury laying down of
platelets and formation of a clot.
Atherosclerosis Ischemia may be due to
Narrowing of the lumen Rupture leading to fibrous cap Embolization
Atherosclerosis More shearing
stress/ increased turbulence Infra renal aorta Iliac bifurcation Carotid bifircation Superficaial femoral
arteries Ostia or renal,
coronary and mesenteric arteries.
Buerger’s Disease Inflammatory reaction of the arterial wall
with involvement of neighboring vein and nerves
2nd to 4th decade of life; male>females Specifically linked to smoking Low socio-economic groups Recently, familial disposition and
autoimmune mechanism has also been postulated
Buerger’s Disease
Buerger’s Disease Pathology
smoking (nicotine)
Increased % carboxy hb
vasospasm damage to the vessel wall
TAO fibrosis
Buerger’s Disease Involves medium and small sized vessels;
those distal to the popliteal artery Very rare upper limb involvement Acute Lesion:
Arteritis, periarteritis, acute phlebitis (migratory in 30%) and periphlebitis.
Invasion of wall by polymorphs and giant cells. Thrombus, with microabscesses
Buerger’s Disease Chronic Lesion
Arteries and veins bound together by fibrosis Nerve involvement Fibroblastic activity and endothelial
proliferation in the thrombus Thrombus organized as fibrous tissue
Clinical Manifestation Pain (Intermittent claudication)
“Claudio”= I limp Cramp like pain Brought on by exercise Not present on walking the first step Relieved by standing still Slight variation each day
Due to accumulation of substance P Site of Claudication:
Group of muscles distal to the site of obstruction
Clinical Manifestation Pain (Intermittent claudication)
Clinical Classificationa) Boyd’s Classification
Grade PainI Pain relieved on continued walkingII Walks in painIII Compelled to take restIV Pain at rest
Clinical Manifestation Claudication distance : distance at which
the pain first appears
Clinical Manifestationb) Fontaine Classification
Clinical Manifestationc) Rutherford Classification
Clinical Manifestation Pain (Intermittent claudication)
Occlusion and site of claudicationSite of Occlusion Claudication site/ other symptomsAorto-iliac obstruction
• Claudication in in both buttocks, thighs and calf
• Absent femoral, popliteal and DP pulses• Impotence (Leriche’s syndrome)
Iliac obstruction • Unilateral claudication in thigh and calf• Unilateral absence of femoral and distal
pulses
Femoropopliteal obstruction
• Unilateral claudication in the calf• Absent distal pulses
Distal obstruction • Ankle pulses absent• Claudication in calf and foot
Clinical Manifestation Pain (Intermittent claudication)
Rest pain Grade IV Boyd’s classification Felt in the foot (most distal parts) Due to ischemia of the somatic nerves (cry of the
dying nerves) Exacerbate on lying down or elevation of foot Worse at night; patient sits in “hen-holding” position Pressure of even bed clothes worsens the pain Lessened by hanging the foot down or sleeping on a
chair Patient may commit suicide
Clinical Manifestation Pain (Intermittent claudication)
Rest pain – “Hen-holding”
Clinical Manifestation Pain (Intermittent claudication)
Critical limb ischemia Persistently recurring ischemic rest pain
requiring regular, adequate analgesia for more than 2 weeks or ulceration or gangrene of foot or toes with ankle pressure <50mmHg or toe pressure <30mmHg
Clinical Manifestation Pain (Intermittent claudication)
Differential Diagnosis1. Nerve root compression (eg: herniated disc)
Sharp lacinating painSudden onset on walkingHistory of back problems
2. Spinal stenosisHistory of back problemsMotor weakness more prominentOnset by standing alsoRelived by change in position
Clinical Manifestation Pain (Intermittent claudication)
Differential Diagnosis3. Arthritic/ inflammatory
Aching painVariable painNot relieved as quickly
4. Baker’s cystSwelling, tendernessRest painSubsides slowlyNot intermittent
Clinical Manifestation Pain (Intermittent claudication)
Differential Diagnosis5. Venous claudication
Bursting type of painRelief speeded by elevationh/o DVTSigns of venous congestion
6. Chronic compartment syndromeBursting painHeavily muscled legsRelief speeded by elevation
Clinical Manifestation Other symptoms
Ulceration Gangrene Loss of senstion Loss of movements
Clinical Assessment History
Can identify the location and severity of the disease Pain:
Location Precipitating and aggravating factors Frequency, duration and evolution
Rule out other causes of pain in the lower limbs Patients with co- morbid conditions who cannot walk
present late with gangrene and rest pain Drug/Medical history Surgical history Family history : first degree with abdominal aortic
aneurysm
Clinical Assessment History
Vascular review of symptoms TIA Difficulty in speech or swallowing Dizziness/ drop attacks Blurry vision Arm fatigue Pain in abdomen after eating Renal insufficiency (poorly controlled hypertension) Impotence Claudication Rest pain or tissue loss
Clinical Assessment Physical examination
Inspection Change in colour Signs of ischemia Bueger’s test Capillary filling test Venous refilling Pregangrenous/ gangrenous part examination
Clinical Assessment Physical examination
Palpation Skin temperature Venous refilling Perpheral pulses
Disapperaing pulse Joint movements / muscle strength Sensations
Auscultation: Bruits
Clinical Assessment Physical examination
Dry vs Wet GangreneDry gangrene Wet gangrene
Dry, shriveled, mummified Odematous, putrified and discoloured
Occurs due to slow and gradual loss of blood supply
Occurs due to sudden loss of blood supply
Clear line of demarcation is present
Vague/ No line of demarcation
No proximal extention Proximal extension
Limited amputation High amputation
Clinical Assessment Physical examination
Dry vs Wet Gangrene
Investigations ABPI
Investigations ABPI
Physiological testingSBP of PT/PT/PA (higher)--------------------------------- = ABPIHigher of the two brachial SBPs
Normal value =>1 Claudication <0.9 Rest pain <0.5 Imminent necrosis <0.3
Note: Normal value doesn’t rule out ischemia Retest after exercise, ABPI may fall Wrong high readings in calcified arteries, e.g. seen in diabetics
&ESRD
Investigations ABPI Note:
Normal value doesn’t rule out ischemia Retest after exercise, ABPI may fall Post exercise ABPI considered POSITIVE when
ABPI fall => 0.2 and/or Failure to return to baseline in 3 minutes
Wrong high readings in calcified arteries, e.g. seen in diabetics &ESRD
Investigations Segmental pressure
Difference of 20-30 mmHg is indicative of significant lesion
Investigations Photo-Plethysmography
Investigation for segmental flow
Infra-red light emitting source + a photosensor
Light decreases when flow increases
Generates a pressure and waveform of different
arteries
A difference of 20-30 mmHg is significant.
Investigations Doppler Ultrasound
(DU) Continous wave DU with
segmental waveforms Doppler shift converted
to audio signal Normal Triphasic Signal
Sharp systolic upstroke
Reversal of flow in early diastole
Low amplitude forward flow
throughout diastole.
Investigations Doppler Ultrasound (DU)
Obstructive disease Initial Loss of reversal flow in early diastole (Bi-phasic) Severe blunting of arterial waveform with decreased
amplitude Worsening only diastolic flow (Mono-phasic )
In case of a proximal obstruction/ stenosis Assessment downstream is less accurate
Shows moving blood but it may/ may not be sufficient
Investigations Doppler Ultrasound
(DU)
Investigations Duplex Ultrasound
Provides with B mode settings (gray settings)
Pulsed Doppler spectral waveforms
Can even detect very low flow states
Color flow data and waveforms for analysis by a computer.
Shows blood flow and turbulence
Peak systolic velocities (PSV) and End diastolic velocities are
recorded.
Investigations Duplex Ultrasound
Change in waveforms Triphasic biphasic Monophasic
Ratio of PSV proximal and distal to occlusion >2.0 indicates a stenosis of 50% or more
Difficult in aoto-illiac segments, especially in obese individuals
(patient should fast overnight)
Investigations Angiography
Invasive techique of visualising the arterial tree Hypaque 45 (Sodium Diatrazoate) is used as a dye
(75 to 100 ml) Course of arteries, constrictions, and distal “Run
off” To plan interventions
1. Transfemoral2. Trans-lumbar (established bi-lateral obstruction)
Seldinger technique is used
Investigations Angiography
Done in 4 stagesi. Dye released at the level of diaphragm in the aorta
Abdominal aorta Celiac artery Sup mesenteric artery Inferior mesenteric artery
ii. Dye released at aortic bifurcation B/L common iliac arteries Hypogastric arteries External iiliac arteries Common femoral arteries Sup Femoral arteries Profunda femoris
Investigations Angiography
Done in 4 stagesiii. Contralateral common femoral artery
Contralateral Sup Femoral artery Profunda femoris Popliteal artery 3 crural arteries Pedal arteries
iv. Ipsilateral common Femoral artery Sup Femoral artery Profunda femoris Popliteal artery 3 crural arteries Pedal arteries
Investigations Angiography
Site of block in Atherosclerosis
Investigations Angiography
Cork-screw pattern of vessels in TAO
Block at multiple sites in small and medium sized arteries
Investigations Angiography
Risk / Complications:a) Groin hematomab) Retroperitoneal bleedingc) Pseudo-anuerysmd) Arterial dissectione) Contrast nephropathyf) Contrast allergy
Investigations CT angiography
IV contrast followed by Ct imaging Thin slices of 0.625mm Allows 3-D reconstruction Improved speed Lesser contrast material Appreciation of thrombus, calcification, etc. better Disadvantages similar to angiography
Investigations Digital subtraction angiography (DSA)
Angiographic images being digitilised by a computer
With substraction of extrenous background (bone, soft tissues)
Investigations MR angiography
Uses Godalinium as contrast Better sensitivity and specificity Disadvantages:
longer study duration Costlier Metallic implants contra-indication Nephrotoxic contrast Fibrosed nodules of skin, eyes and joints (rare
complication)
Investigations Carbon Dioxide angiography
CO2 as contrast agent In cases of renal insuffieciency CO2 temporarily displaces blood but dissolves in
3-5 minutes Poor detail Significant patient discomfort Gas trapping mesenteric ischemia
Investigations General Investigations
ECG ECHO Lipid profile COPD Blood tests to exclude
Anemia DM Deranged RFT High blood viscosity (polycythemia and
thrombocythemia)
Investigations Intravascular
ultrasound (IVUS) Catheter based
intravascular ultrasound
Provides transverse and 360 degree image of the lumen of the vessel
Qualitative data about the wall anatomy
Investigations Brown’s vasomotor index
For Buerger’s disease Test of vasospasm Block the nerves with Local anesthesia to
predict efficacy of Sympathectomy Rise in skin temperature is recorded Index = Rise in skin temperature – Rise of mouth
temperatureRise of mouth temperature
Index =>3.5 is positive for sympethectomy
Management Conservative management
Indications: Ankle pressure >60mmHg Femoral pulse + No rest pain No tissue loss Controlled infection (eg diabetic patient) Unfit for surgery ABPI >0.5 (Relative indication)
Management Conservative management
Stop smoking Keep walking Reduce weight (obese individuals) Exercise Diabestes and hypertension Care of feet Buerger’s position Buerger’s exercise
Management Conservative management
Drugs Analgesics- Aspirin Vasodialtors
Cilostazol (phosphodiasterase inhibitors) Pentoxyphylline (phosphodiasterase inhibitors) Prostacycline
Platelet aggregation inhibitors Clopidrogel Aspirin Prostacycline
Management Conservative management
Drugs To Control
Diabetes Hypertension Dyslipidemia Atherosclerosis Infection
Note: Risk of limb Loss to be explained to the patient (Failure in 25% of patients)
Opening up of collaterals or change of gait with less usage of the affected muscle
Management Indirect surgeries
Sympathectomy Chemical Surgical Indications:
Rest pain Skin ulcerations TAO Elderly patient (senile gangrene)
Management Indirect surgeries
Sympathectomy Chemical
Produces cutaneous vasodilatation Injection in front of the lumbar fascia which contains
sympathetic trunk; Under C-Arm 5ml phenol in water is inected in front of 2nd, 3rd and
4th lumbar vertebra
Management Indirect surgeries
Sympathectomy Surgical (pre-ganglionic sympathectomy)
Abdomen opened with oblique incision under genral anasthesia
Dissection through flat abdominal muscles, and peritoneum
The sympathic chain is situated medial to the medial margin of psoas muscle
Rt side overlapped by IVC Lt side overlapped by aorta Sympathetic chain identified by the presence of ganglia First lumbar ganglia is as high as crus of the diaphragm
Management Indirect surgeries
Sympathectomy Surgical
Sympathectomy from 1 to 4th lumbar ganglion Closed the site in layers
Note: in case of bilateral surgery; preserve L1 of atleast one side causes retrograde ejaculation.
Management
Management Surgical Management
Surgical Revascularization Procedures Open Endo-vascular
Amputation
Management Surgical Revascularization Procedures
Open vs endo-vascular Trans-Atlantic Inter Society Documentation
Management of Peripheral Arterial Disease (TASC) 2000
TASC –II in 2007“Endovascular therapy is the treatment of choice for Type A lesions and surgery is the treatment of choice for Type D lesions. Endovascular treatment is the preferred treatment for Type B lesions and surgery is the preferred treatment for good risk patients with Type C lesions”
Management TASC –II (Aorto-iliac)
Management TASC –II (Aorto-iliac)
Management TASC –II (Aorto-iliac)
Management TASC –II (Aorto-iliac)
Management TASC –II (Femoro-popliteal)
Management TASC –II (Femoro-popliteal)
Management TASC –II (Femoro-popliteal)
Management TASC –II (Femoro-popliteal)
Management Open Surgical Management (Aorto-iliac
disease) Aorto-bifemoral bypass with a prosthetic graft via
transabdominal or retroperitoneal approach. End to end or end to side proximal anastomosis Nervi erigentes should be taken care of (damage
will lead to retrograde ejaculation) in the area of CIA
Mortality 5%
Management Open Surgical Management
Choice of Graft (Conduits) Great Sephanous vein
Preferred for lower limbs with better patency rates (90% First yr and 60% five yrs)
Should preferentially be used in all below knee by-passes Can be used in situ
Better size match Removal of valves with valvulotome
Reversed No need of disruption of valves May be harvested endoscopically
No added advantage of one over the other
Management Open Surgical Management
Choice of Graft (Conduits) PTFE (Polytetrafluoroethylene)
Can be used as a replacement of LSV Poorer results compared to LSV (50% in five yrs) New: with heparin coating
Dacron is a brand name of PTFE
Management Open Surgical Management
Choice of Graft (Conduits) Small sephanous vein Basillic vein Cephalic vein
All these three veins have very thin walls, hence no good results
veins when joined to increase the length gives poor results
Cryo-preserved arteries Cadevaeric arteries preserved in cold
Bovine pericardial patches
Management Open Surgical Management (Aorto-iliac
disease) Aorto-bifemoral bypass
Midline or transverse abdominal incision CFA and branches exposed through groin incision Small bowel retracted to right Posterior peritoneum is open Retroperitoneal tunnels are made to groin. Heparin 5000U given iv bolus and vessels clamped
Management Open Surgical Management (Aorto-iliac
disease) Aorto-bifemoral bypass
Vertical incision on anterior aspect of Aorta Dacron sutured end to side (taking all the layers) The Limbs fed to the groin sutured end to side to
CFA Posterior peritoneum closed over peritoneum
Management Aorto-bifemoral bypass
Management Open Surgical Management (femoro-popliteal)
Open groin surgery CFA endarectomy + profundoplasty/ iliofemoral bypass
In case of added proximal (iliac) occlusion CFA endarectomy + profundoplasty / iliofemoral
bypass + iliac stenting
In case of added distal (SFA)occlusion CFA endarectomy + profundoplasty +SFA stenting/
femoropopliteal bypass
Management Open Surgical Management
Endarterectomy Open:
When it involves short segment of big arteries Also called “dis-obliteration/ reboring” Heparin 5000U given pre-opeartively Artery is exposed after placing clamps Distal clamp applied first Longitudinal incision taken oven the occlusion till the
plaque is reached
Management Open Surgical
Management Endarterectomy
Open: Plane created
between plaque and media
The plaque is removed with the diseased intima
In case of thrombus, it is removed
Closed with non absorbable fine
sutures directly or a vein graft
Post op anticoagulant therapy with warfarin
Management Open Surgical Management
Endarterectomy Closed
Artery exposed and clamped Proximal and distal transverse incisions taken Plane created between plaque and tunica media Wire loop passed from distal to lower arteriotomy
insion, stripping the plaque Can be used in relatively longer occlusions
Management Open Surgical Management
Endarterectomy Balloon
Artery is exposed after clamping Proximal arteriotomy is made Fogarty ballon catheter is passed
Management Open Surgical
Management Endarterectomy
Passed beyond the obstruction
Ballon is inflated Pulling the catheter
removes the atheroma
More commonly used for emboli (as they are comparetively loosely
adherant)
Management Open Surgical Management
Profundoplasty Repairing of profunda femoris Arises posterior to CFA The vessel is dissected out and clamps are applied Arteriotomy extending from CFA to distal to
occlusion Atherectomy is then performed
Management Open Surgical
Management Profundoplasty
Defect is them closed by a vein patch
On table angiography is then performed to check for patency
May be done in adjunct to bypass
surgeries
Management Open Surgical Management
Femoro-popliteal bypass In patients with SFA and popliteal artery occlusion with a
distal segment of patent popliteal artery. In continuity with any crural artery Longitudinal groin incision to access the CFA Popliteal artery is exposed medially from thigh or the leg In above knee bypass, incision proximal to the knee to
access popliteal artery In below knee bypass, popliteal fossa is opened
Management Femoro-popliteal
bypass Polpileat vein is held
in Silastic loops Graft is tunnelled
and placed at the anastomotic site
Sephanous vein graft can be used In situ (requires
desruption of valves) Reversed, can be
accessed by a parallel skin incision
Management Open Surgical Management
Infrapopliteal bypass Disease involving popliteal artery and proximal tibial
arteries. the target artery must have luminal continuity with
the foot Stenosis upto 50% is accepted as patent for surgery Calcification also not considered a contra-indiaction. SFA or Popliteal artery is used for “inflow”
Management Open Surgical Management
Infrapopliteal bypass Access to PTA with dissection and separation of Soleal
muscle attachment from tibea access to PTA and PA Access to ATA with anterolateral incision on
legseparation of ant tibial muscle and external longus muscle ATA. Separation of interosseus membrane for tunneling of the graft.
Small veins can be used for anastomosis Or PTFE graft can be used
Management Open Surgical Management
Other bypassesA. Axillofemoral graft
Tunnelled subcutaneously between the axillary artery proximally, to reachone or both CFA
Low patency ratesB. Femoro-femoral crossover bypass
Crossover graft by tunnelling a prosthetic graft subcutaneously above the pubis between the groins
Management
Management Endovascular management
Basically involves gaining access into transmural space via percutaneous femoral artery puncture
Balloon angioplasty Subintimal angioplasty Stenting Stent graft Variations of balloon angioplasty
Management Endovascular management
Balloon angioplasty Guide wire is negotiated through the stenosis or
occlusion Then a balloon is inflated to open the occlusion It is kept inflated for approx 1 minutes with high
pressure then deflated May be combined with stenting
Management Endovascular management
Balloon angioplasty Very good results for dilating the iliac and
femporopopliteal segments Below knee procedures are less successful 98% success in CLI (extremely good results) Limb salvage rate of 91% over 5 fyrs Failure in TASC D patients
Management Endovascular management
Subintimal angioplasty Creating an arterial dissection purposely
begenning at the proximal end of the oclusion The guide wire is made to re-enter the lumen at
the diastal end of occlusion Use of balloon angioplasty to increase the
diameter of the false lumen Poor results 3 yrs patency rates being only 30% But good for critical limb ischemia
Management Endovascular management
Subintimal angioplasty
Management Endovascular management
Stenting If the vessel fail to remain dilated use stents Stainless steel stents May be introduced on a balloon catheter and
placed in position Self expanding stents (nitinol), which expand on
withdrawing the sheath Angioplasty (balloon) + stenting > primary
stenting But primary stenting > only angioplasty Poor results in TASC D patients
Management Endovascular management
Stenting
Management Endovascular management
Stenting
Management Endovascular management
Stent garft Expanded PTFE (ePTFE) with external nitinol stent Inner surface bonded with heparin Extremely flexible Can close conform to the shape of artery (esp: SFA) Self expanding stents Easier with better patency rates than atherectomy. It is easier, with more better technical succes
comapred t o PTA Few studies show similar results comapred to bypass
Management Endovascular
management Cutting balloon
Originally designed for coronary arteries
The balloon has three or four atherotomes or micro-surgical blades
These are mounted longitudinally on the balloon
The blades score the lesion and dilate the lesions
Management Endovascular management
Cryoplasty Apoptosis by cooling Designed by Polar Cath Peripheral Dilatation
System (Boston Scientific) Balloon filled with nitrous oxide gas To cool to -10 degrees C Supposed to prevent restenosis
Management Endovascular management
Endovascular atherectomy Excision atherectomy catheters remove and collect the
atheroma Ablative atherectomy device fragment it Rotational cutters turn at the speed of 8000rpm to shave the
plaque and collect in a storage chamber Laser atherectomy has a cold tipped laser that delivers burst
of ultraviolet Xenon energy in short pulse durations
Results same as balloon angioplasty
Management Endovascular management
Endovascular atherectomy
Rotational cutter Laser tipped
Management Amputation
Indication for amputation Dead Limb
Gangrene Deadly Limb
Wet gangrene Spreading cellulitis
Dead Loss Limb Severe rest pain with Ischemia Paralysis Contracture
Management Amputation
Choice of amputation Below knee amp[utation (BKA) Above knee amputation (AKA Ray amputation Transmetatarsal amputation Miscellaneous
Syme’s Chopart’s Lisfranc’s
Management Amputation
Level of amputation Skin perfusion pressure >=40 mmhg Transcuatneous oxygen pressure >= 30mmhg
Predictors for Transmetatarsal amputation: Toe Blood Pressure >=30 mmhg Ankle Blood Pressure >= 80 mmHg
Management Amputation
Below Knee Amputation Above Knee Amputation
Poor Healing Better Healing
More chances of revision/ healing by secondary intention
Less chances of revision
Better ambualtion Poor ambulation
Management Amputation
Ray amputation
Management Amputation
A. Syme’s B. Chopart’sC. Lisfranc’sD. Transmetatarsal
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