Lower Extremity Flashcards
What is Leriche syndrome?
Triad: absent femoral pulses, intermittent claudication and impotence
Name 4 conditions that mimic PAD?
Spinal stenosis, OA, venous claudication, radiculopathy
What size would be an indication to repair a femoral aneurysm
Normal - 1 cm, indication for repair 3.5 cm (or 2.5 cm if intraluminal thrombus)
What conditions are associated with true femoral pseudoaneurysms?
- Old
- Male
- Smoking
- NTN
- Wegners granulamotosis
- Parkes-Weber
- Bechets
How do most femoral aneurysms present?
65% with claudication/CLI from embolic symptoms
What is the prefered conduit for interposition graft of femoral pseudoaneurysms?
Prosthetic - dacron or PTFE
Should you resect the aneurysm sac during femoral aneurysm repair?
Usually not - may injure surrounding structures
How can you obtain proximal control for large femoral aneurysms (2 ways)?
Proximal balloon occlusion from contralateral femoral.
Retroperitoneal exposure of suprainguinal external iliac artery
What are 3 contraindications to ultrasound guided compression?
Infection, ischemic skin changes, puncture above inguinal ligament,
What does thrombin do?
Converts fibrinogen to fibrin for direct clot formation. “Short circuits” coag cascade and therefore still works with heparin/warfarin on board
How much thrombin is usually required to induce thrombosis?
1000 units or 1 mL (comes in 1000 IU/mL)
What are 3 contraindications to bovine thrombin?
Allergy, infection, pregnancy
What are indications for an open surgical repair of femoral pseudoaneurysm?
- Contraindication to thrombin
- Failure of thrombin
- Skin ischemia
- AV fistulas
What is the embryologic origin of persistent sciatic artery?
Umbilical artery - should regress at 3 months gestational age
What percentage of popliteal aneurysms are bilateral?
50%
What percentage of popliteal aneurysm patients have an AAA?
30-50%
What percentage of AAA have coexisting popliteal aneurysms?
15%
What size threshold for repairing popliteal aneurysms?
> 3 cm or > 2 cm if ++ thrombus, symptomatic any size
What are 4 contraindications to endovascular popliteal aneurysm repair?
- Insufficient landing zone < 2cm proximal and distal
- Not able to take antiplt
- Gardner/carpenter/jobs with a lot of knee flexion
- Extremely tortuous
How long should patients be on dual antiplatelet after popliteal stenting?
4-6 weeks
How much should you oversize a popliteal viabhan for aneurysm repair?
10-15%
Which approach should you use to repair a large popliteal aneurysm that compresses adjacent nerves?
Posterior, unless very proximal
When should you treat an acutely ischemic limb secondary to popliteal aneurysm with thrombolysis?
Insufficient outflow vessels for bypass. Limb must be able to withstand 12-18h of ischemia
What is the objective criteria for Rutherford 0, category 0 CLI?
Normal treadmill or reactive hyperemia test
What is the objective criteria for Rutherford grade 0, category 1 CLI?
Completes treadmill exercise (5 min at 2mph at 12% incline), ankle pressure after exercise > 50 mm Hg
What is the objective criteria for Rutherford category 2 CLI?
Between categories 1 and 3
What is the objective criteria for Rutherford grade 1 category 3 CLI?
Cannot complete treadmill test, ankle pressure after exercise < 50 mm Hg
What is the objective criteria for Rutherford grade 2 category 4 CLI?
Resting ankle pressure < 40 mm Hg or barely pulsatile ankle or metatarsal PVR, toe pressure < 30 mm Hg
What is the objective criteria for Rutherford 3 category 5 CLI?
Resting ankle pressure < 60 mm Hg, ankle or metatarsal PVR flat or barely pulsatile, toe pressure < 40 mm Hg
What is the objective criteria for Rutherford grade 3, category 6 CLI?
Same as category 5 - resting ankle pressure < 60, toe pressure < 40, flat ankle/metatarsal PVR
What is the clinical description for Rutherford grade 3, category 6 CLI?
Major tissue loss extending above transmetatarsal, functional foot no longer salvageable
What is the clinical description for Rutherford grade 3, category 5 CLI?
Minor tissue loss, non healing ulcer/focal gangrene
What is the clinical description for Rutherford grade 2, category 4 CLI?
Ischemic rest pain
What is the clinical description for Rutherford grade 1, category 3 CLI?
Severe claudication
What is the clinical description for Rutherford grade 1, category 2 CLI?
Moderate claudication
What is the clinical description for Rutherford grade 1, category 1 CLI?
Mild claudication
What is the clinical description for Rutherford grade0, category 0 CLI?
Asymptomatic
What is the annual mortality rate of a diabetic with a foot ulcer?
10%
What is the 5 year mortality for diabetics who undergo a major amputation?
70%
What percentage of diabetic patients with a major amputation will require a contralateral limb amputation?
Up to 40%
How do diabetics develop equinis deformity?
Somatic neuropathy > muscle wasting > flexor extensor muscle imbalance > weakening of anterior calf muscle.
What are 2 effects sympathetic autonomic nerve dysfunction have on diabetic feet?
1 - Reduced sweating - dry fragile skin prone to fissuring
2-Microvascular AV shunt and impaired regulation of the skin, so foot may feel warm and well perfused and give false sense of security
What percentage of diabetic foot ulcers have contribution from arterial disease?
50%
What is PEDIS?
A way of describing diabetic foot ulcers: perfusion, extent, depth, infection and sensation.
What are important clinical signs of an acute Charcot foot?
Diabetic with unilateral hot swollen foot is Charcot foot until proven otherwise and requires offloading to prevent “rockerbottom” feet.
What does a Semms-Weinstein monofilament evaluate?
Sensation - to test diabetic patients risk of foot ulceration from neuropathy
What TBI is predictive of wound healing?
0.6 and above
What PVR amplitude threshold would indicate a wound was not likely to heal?
PVR < 5 mm
What PPG amplitude threshold would indicate a wound was not likely to heal?
< 50 mm Hg
What are 4 types of foot amputation?
1-transmetatarsal
2-Lisfranc (disarticulate the metarasals)
3 - Chopart (remove cuboids)
4 - Symes (whole foot)
What threshold tcPO2 is considered minimum for wound healing?
TcPO2 > 40 mm Hg for wound healing
What skin perfusion pressure (SPP) is predictive of healing
> 50 mm Hg
What is the intracompartmental pressure threshold for doing fasciotomies?
Absolute - 30 mm Hg - but not a good measure. Arterial pressure changes will alter compartmental pressure. MAP - ICP > 40 mm Hg dynamic pressure threshold may be more useful.
Why does ischemia reperfusion injury cause compartment syndrome?
oxygen radical generation increases microvascular permeability and efflux of plasma proteins with progressive interstitial edema
What are 6 risk factors for compartment syndrome due to ischemia reperfusion injury?
1 - ischemia > 6h
2 - young
3 - insufficient arterial collaterals
4 - poor backflow from embolectomy
5 - acute time course of occlusion
6 - hypotension
What is the risk of compartment syndrome if popliteal artery is injured in trauma?
High - 60%
What are 4 vascular causes for compartment syndrome?
1 - ischemia reperfusion injury
2 - venous outflow obstruction
3 - arterial/venous trauma
4 - hemorrhage
What are 4 non vascular causes for compartment syndrome?
1 - fracture (injured muscle causes bleeding in the compartment)
2 - iatrogenic (punctures in coagulopathic, dorsal lithotomy ORs, cast immobilization)
3 - crush injury
4 - “secondary” - SIRS + massive fluid resuscitation
What are 2 ways to measure compartment pressures?
Arterial line, stryker needle
What is a normal compartment pressure?
< 10 mm hg
Where should you test for numbness for an anterior compartment syndrome?
First dorsal webspace - deep peroneal distribution
Name 4 ways of blunting oxygen radical formation to reduce intracompartmental pressure
1-Mannitol
2- Allopurinol
3-thromboxane A2
4-melatonin
Only in animal models now
How does myoglobinuria lead to nephrotoxicity?
Vasoconstricts, renal tubular cast formation, direct heme protein induced cytotoxicity
How do you treat myoglobinuria?
Aggressive crystalloid infusion, forced diuresis with mannitol, alkalinazation of urine with bicarb (urine pH > 6.5)
Why do you use aggressive crystalloid and alkalinzation to treat myoglobinuria?
Heme proteins are not nephrotoxic in the abscence of hypovolemia and aciduria
Name 6 absolute indications for fasciotomy
1 - tense compartment with either 2 or 3
2 - pain on passive motion of muscles in the affected compartment
3 - paresis of muscles in the affected compartment
4 - tense compartment cannot be examined because obtunded patient
5- ICP - MAP < 40
6 - ICP - dBP < 10
What is the most common nerve injured during fasciotomy? Where does it course?
Superficial peroneal nerve. Descends along the septum separating anterior and lateral compartments
How long should fasciotomy skin incisions be?
15 - 20 cm
Where do you make the incisions for a 4 compartment fasciotomy?
Medial - 1-2 cm posterior to tibia, avoiding saphenous vein and nerve
Lateral - 4 cm from crest of tibia, 4/5 cm distal to fibular head to avoid injury to common, superficial and deep peroneal nerves
What is contained in the anterior compartment of the lower leg?
Muscle - tib ant, extensors (digitorum longus/hallicus longus)
Vessels - AT artery/veins
Nerve - deep peroneal
What is contained in the deep compartment of the lower leg?
Muscle - Tib post, Flexors (hallicus, digitorum), popliteus
Vessels - PT artery and veins
Nerve - Tibial
What is contained in the superficial compartment of the lower leg?
Muscle - Gastrocnemius, soleus, plantaris
Vessels - None
Nerve - None
What is contained in the lateral compartment of the lower leg?
Muscle - peroneus longus/brevis
Vessels - peroneal artery and veins
Nerve - superficial peroneal
Where do you make your incision for a “single - incision” 4 compartment fasciotomy?
Lateral incisoin over the fibula
What is contained in the anterior compartment of the thigh?
Muscle - quads (rectus femoris, vastus medialis, lateralis, intermedius), sartorius
Vessels: Femoral artery and vein
Nerve: Femoral nerve
What is contained in the medial compartment of the thigh?
Muscle - adductors (long, brev, mag, min), obturator, pectinius gracilis,
Vessels: Profunda artery and vein
Nerve: Obturator nerve
What is contained in the posterior compartment of the thigh?
Muscle - biceps femoris, semimembranosis, semitendonosis
Vessels: None
Nerve: Sciatic nerve
Where do you make your incision for a thigh compartment decompression?
Medial rarely needs decompression. Lateral incision at intertrochanteric line to lateral epicondyle
How do you open the medial compartment of the thigh?
Medial incision over adductor muscle group - rarely needed
How do you open the posterior compartment of the thigh?
Reflect vastus lateralis medially to expose lateral intermuscular septum
How do you open the anterior compartment of the thigh?
Cut through iliotibial band along length of incision (intertrochanteric line)
What are the compartments of the foot?
Variably described - medial lateral superficial calcaneal
Where do you make incisions for a foot fasciotomy?
2 plantar incisions - Medial to D2 and lateral to D4. Calcaneus requires separate incision for decompression
Must avoid medial and lateral plantar neurovasc bundles.
What are 5 ways of healing fasciotomy sites?
1 - secondary intention
2-delayed primary closure
3-split thickness skin graft
4 - myocutaneous flap
5-gradual dermal apposition
What is a Volkmann contracture?
Classic late consequence of missed compartment syndrome - ischemic muscle and nerves replaced with fibrotic tissue leaving compartment firm and dysfunctional
What is the diagnostic criteria for chronic
What is the diagnostic criteria for chronic exertional compartment syndrome?
Usually young athletes, reproducible, bilateral pain after 30 mins of exercise that abates with 30 mins of rest.
1) Resting ICP > 15
2) ICP > 30 after 1-2 mins of exercise
What is the treatment for chronic exertional compartment syndrome?
Avoid precipitating activities. Fasciotomy or fasciectomy (removal of an ellipse of fascia)
What percentage of amputations are due to diabetes?
25-90%
Are amputation rates increasing or decreasing over time?
Despite increase in diabetes, amputation rates are decreasing
Which patients are more likely to be offered primary amputation instead of revascularization?
regional variation, non-white, low income, no insurance
What is the overall mortality rate of major amputation?
8%
What percentage of amputation patients have stump complications?
10%
Which medications should you put a patient undergoing major amputation on?
antiplatelet and statin. also need to optimize glucose and other medical comorbidities.
What percent of amputation related deaths are due to PE?
20%
What is cryoamputation?
For moribund patients - place large plastic bag with dry ice to freeze off the limb to control infection and alleviate time pressure for urgent amps - can be maintained for several weeks
How do you select degree of amputation based on physical examination?
1-extent of gangrene and infection dictates maximal length. Dependent rubour = gangrene because it is ischemic.
2-pulse proximal to site = wound will heal. But no pulse does not mean necessarily that it wont heal.
What skin temperature threshold predicts wound healing for selecting level of amputation?
90F
What absolute ankle pressure is required to heal BKA?
80 mm Hg
What toe pressure indicates healing?
> 30 mm Hg
How can you use arteriography to plan amputation level/wound healing?
Not useful. Infact, angiographic patency tended to be greater in limbs with failed/delayed healing!
What physiologic tests are available to test tissue perfusion/oxygen delivery? Which is most accurate?
1 - intradermal isotope xenon 133/iodine 125 (unreliable)
2- Tc99 sestamibi scintigraphy
3 - intracutaneous iodine 123
4- skin fluorescence with UV light after IV injection of fluoroscien (more affected by inflammation/cellulitis compared with scintigraphy)
5- tcPO2 - most accurate
What tcPO2 readings indicate wound healing?
> 40 mm Hg heal, < 20 mm Hg won’t heal
What is the ambulatory rate for patients with a BKA?
80%
What is the ambulation rate for AKA?
40-50%
What is the ambulatory rate for amputations with knee disarticulations?
30%
What is the ambulation rate for hip disarticulation amputations?
< 10%
How much increased energy expenditure is required for ambulation with BKA with long stump? Short stump?
10%, 40%
What percentage increase in energy is required to walk with an AKA?
60%
What percentage increase in energy is required to walk with a hip disarticulation amputation?
80%
What percentage of increased energy expenditure is required to walk with a knee disarticulation amputation?
70%
What dressing options are available for BKA? Which should you use?
Soft gauze, rigid plaster, prefabricated immediate pneumatic postop prostheses (IPOP). Some data suggest IPOP better healing, faster rehab, less complications compared with gauze.
What percent of diabetic amputees lose their other limb withing 5 years?
Up to 30%
Why is it advisable to not over strip the periosteum when doing amputations?
Limits vascular supply - can lead to ring sequestra (bony lesions)
What are the bones of the foot?
7 tarsals, 5 metatarsals, 1st toe only one with 2 distal phalanges, medial and lateral sesamoid bones stabilize first toe.
How do you do a ray amputation?
Racket incision, resect digit and metatarsal head, typically excise sesamoid bones, excise flexor tendons
Why might you consider a transmetatarsal amputation vs. a 1st digit ray amputation
1st digit ray amp significantly alters gate and up to 60% get recurrent ulcers
How do you perform a transmet? 4 steps
1 - incision over distal metatarsals
2-Excise extensor tendons and incise periosteum
3- bone saw across the metatarsals, each 3 mm shorter than the last for a 30 degree angle to help with lift off.
4 - Divide the plantar myofascial attachments to metatarsal head and remove tendons and sheaths that are poorly vascularized
Name 3 proximal foot amputations
1 - Lisfranc’s
2- Chopart’s
3 - Syme’s
What are Boyd and Pirogoff amputations?
Hindfoot, used in peds to preserve length/growth centres. Rarely used.
How can you avoid an equinis deformity in mid foot amputations?
Divide or lengthen achilles tendon. Mid foot divides the strong ankle extensor attachments and the achilles plantar flexor forces are unopposed.
How do you perform a Lisfranc’s amputation? 5 steps
1- Long plantar flap
2- disarticulate 1/3/4/5 tarsometatarsal joints,
3 -2 is transected 1-2cm distal to medial cuniform bone.
4- Release achiles tendon.
5-Close plantar fascia.
How do you perform a chopart’s amputation? 5 steps
1 - long plantar flap
2- disarticulate at talocalcaneonavicular joint and calneocuboid joint
3 - acheilles tenectomy recommended
4- reatach extensor hallicus longs and tibialis anterior tendons to talar neck and extensor digitorum longus to calcaneus
5- close
How do you perform a Syme’s amputation?
1 - incision across the ankle distal to each malleolus
2 - dorsalis pedal artery ligated
3- heel fat pad carefully dissected - preserving post-tib artery
4-ankle disarticulated
5-malleoli sawed
6- holes drilled in tibia and fibula to secure heel directly under tibia.
How do you draw out the posterior flap for a BKA?
15 cm below tibial tuberosity (4 fingerbreadths) - Take circumference, anterior incision = 2/3, posterior flap 1/3 length
How do you draw out the incision for a skew flap BKA?
15-20 cm below tibial tuberosity, anterior point. Make rounded flaps with a string 1/4 the length of circumference. Helps if the skin isn’t healthy enough for a posterior flap
What are the 4 most common collateral pathways that prevent aortoiliac disease from presenting with CLI
1 - superior mesenteric artery > inferior mesenteric artery > superior rectal artery >
- middle and inferior rectal arteries > internal iliac arteries
- obturator / internal pudendal arteries > common femoral arteries
2- intercostal, subcostal, and lumbar arteries > superior gluteal and iliolumbar arteries > internal iliac arteries > external iliac arteries.
3 - intercostal, subcostal, and lumbar arteries > circumflex arteries > external iliac arteries
4 - subclavian arteries > internal thoracic (mammary) arteries > superior epigastric arteries > inferior epigastric arteries > external iliac arteries (the Winslow Pathway 7)
What are the differences between people who get isolated aortoiliac disease versus multilevel
Isolated - younger, male = female, smoker, hypercholestoremia
Multilevel - older, male, DM, HTN, CAD/CVA, reduced life expectancy
What is small aortic syndrome?
Young female smokers - diffusely calcified stenosis, don’t have the typical atherosclerotic risk factors
What resting difference between brachial and thigh pressure represents a significant aortoiliac stenosis?
20 mm Hg
Why can you sometimes feel palpable pedal pulses in someone with aortoiliac occlusive disease?
Extensive collaterals - may only lose pulses after exercise
What percentage of claudicants require an intervention in 5 years?
30%
What are the annual mortality and limbloss rates of claudicants?
5%, 1%
What are 4 indications for surgical intervention for AIOD?
1 - disabling claudication
2- restenosis after endovascular therapy
3- CLTI
4- shaggy aorta
What are the 3 criteria for a diagnosis of chronic limb threatening ischemia?
1) Persistent pain > 2 weeks requiring opoids
2) Ankle pressure < 50, Toe pressure < 30
3) Tissue loss
What profunda popliteal index would indicate that an inflow procedure would be insufficient to revascularize a leg (i.e. require distal procedure too)
0.25
How do you access the profunda from an anterior approach?
Incise and dissect down between the vastus medius and sartorius
How do you access the profunda from a medial approach?
Incise and dissect between the adductor longus and sartorius
Do vein cuffs offer a patency advantage for infrainguinal bypasses?
Yes - 52% patency PTFE + cuff vs. 29% no cuff at 2 years
What is the patency of vein vs PTFE in above knee bypasses?
70% vein, 40% PTFE at 5 years
What is the patency of vein compared with PTFE in below knee bypasses?
70% vein, 50% PTFE at 4 years (Veith)
What is the patency of fem tib with vein vs PTFE?
50% vein, 10% PTFE at 4 years (Veith et al)
What are 4 ways you can assess the patency of your graft intra-op?
1) Palpation
2) XA (can detect 27% defects not seen with palpation!)
3) Duplex
4) Angioscopy
What duplex criteria would suggest you should prophylactically repair an infrainguinal bypass?
PSV > 300 cm/s, Velocity ratio 3.5-4
What follow up infrainguinal bypass duplex criteria should prompt you to get an angio?
Low flow < 40 cm/s or ABI decrease by 0.15
What are 7 BKA flap options?
1 - Posterior flap
2-Skew flap
3 - Fish mouth
4 - Medial skew flap
5 - Ertl (tib/fib attached together for better biomech)
6 - Guillotine in septic emergencies
7 - Cryoamputation dry ice for patients that are too sick for OR/GA
What percentage of BKAs do not heal primarily?
20-30%
What percentage of BKA patients require higher level amputations?
20%
What percentage of through knee amputation patients require higher level amp?
15-30%
Where do you make the femur transection in an AKA?
12 cm above femoral condyles
What is the 30d mortality for major lower extremity amputation?
10%
What percentage of amp patients experience chronic pain?
95%
What percentage of amputation patients have contractures?
3-5%
What is the EUCLID trial and what were the main results?
Compared ticagrelor and plavix - no difference in symptomatic peripheral artery disease patients
Name 2 drugs that can be prescribed for intermittent claudication symptom relief
- Naftidrofuryl
- Cilostazol
What were the findings of the CLEVER trial for aortoiliac disease?
Supervised exercise and stent revascularization results in better outcomes than medical therapy alone at 18 months. Functional status and health related quality of life however did not differ.
How should you treat SFA instent restenosis? What are relevant trials?
DCB - FAIR and PACUBA trials showed better patency and less recurrent restenosis with DCB vs PBA
Which registry shows pedal angioplasty has benefit for rate of wound healing and time to wound healing?
RENDEZVOUS (Japan)
What are 4 indications for aortoiliac endovascular intervention?
- Hip/buttock/calf claudication
- CLTI (though usually multilevel diffuse disease)
- Younger patients to minimize sexual dysfunction
- Embolization (contraversial).
What are 5 relative contraindications to aortoiliac endovascular intervention?
- Renal impairment
- Juxtarenal disease
- Heavy calcification.
- Hypoplastic aorta.
- Juxtaposition to aneurysmal disease
What is a “technical success” for an endovascular aortoiliac intervention?
Less than 20% residual stenosis and less than 10 mm Hg systolic pressure gradient
What is a paradoxical embolism? How does it typically present?
- Clot from the venous system travels through a patent foramen ovale and into the arterial system.
- Young patient with acute arterial ischemia and simultaneous DVT
What is the description, findings, and doppler signals associated with Class 2B acute limb ischemia?
- Description: Immediately threatened
- Findings: sensory loss more than just toes + rest pain, mild to moderate muscle weakness
- Doppler signals: arterial signals inaudible, venous audible
What is the description, findings, and doppler signals associated with Class 2A acute limb ischemia?
- Description: Marginally threatened
- Findings: sensory loss minimal, no muscle weakness
- Doppler signals: arterial inaudible, venous audible
What is the description, findings, and doppler signals associated with Class 3 acute limb ischemia?
- Description: Irreversible
- Findings: sensory/muscle weakness - profound (anesthetic and paralysis/rigor)
- Doppler signals: arterial and venous inaudible
What is the description, findings, and doppler signals associated with Class 1 acute limb ischemia?
- Description: Viable
- Findings: sensory/muscle weakness - none
- Doppler signals: arterial and venous are audible
Why should you avoid revascularizing Class 3 acutely ischemic limbs?
Futile and may have adverse systemic effects including cardiac arrest due to acidosis and hyperkalemia.
What are 10 relative contraindications to thrombolysis?
- Major surgery/trauma within 10 days
- HTN sBP >180
- CPR within 10 days
- Pregnancy
- Intracranial tumour
- Diabetic hemorrhagic retinopathy
- Recent eye surgery
- Hepatic failure
- Bacterial endocarditis
- Puncture of noncompressible vessel
What are 5 absolute contraindications to thrombolysis?
- Active bleeding disorder
- GI bleed within 10 days
- Cerebrovascular event within 6 months
- Intracranial or spinal surgery within 3 months
- Head injury within 3 months.
What are the doses for a “low dose” continuous infusion of tPA?
1 mg bolus followed by 0.5 - 1 mg/h for 10-12 h or overnight
What is a high dose tPA regimen for continuous thrombolysis?
10 mg pulse spray bolus followed by 0.05 mg/kg per hour continuous infusion for 6 hours.
What is the maximum dose of tpa infusion?
4 mg /h
What fibrinogen level do you discontinue continuous tpa infusions?
Fibrinogen less than 100 mg/dL
What did the Rochester study show when comparing thrombolysis to immediate operation for acute limb threatening ischemia?
1 year amputation free survival: 75% with thrombolysis and 52% with surgery.
Subsequent analysis showed that surgery patients had more mortalities due to intra-op cardiac events.
What were the main outcomes of the STILE trial?
Thrombolysis better when ALI symptoms < 14 days
> 14 days: surgery has lower amputation rates compared with thrombolysis at 6 months (3 vs. 12%)
< 14 days: thrombolysis had lower amputation rates (11% vs 30%)
What are the post-thrombolysis graft patency rates at 2 years?
10-40% - an argumnt for replacing failed graft if an anatomic lesion is not identified as the etiology of graft failure
What are 3 advantages of using percutaneous mechanical thrombolysis for acute limb ischemia
- Faster - less ischemic time compared with pharmocologic
- Lower pharm dose therefore less risk of hemorrhagic complications
- Can be used in patients with contraindications to thrombolysis (e.g. recent surgery)
What is the mortality rate associated with acute limb ischemia?
Unacceptably high - 10-25%
Though limb salvage rates have improved with modern techniques, death has not substantially changed.
Why does compartment syndrome happen more often with open surgical revascularization and percutaneous mechanical thrombectomy when compared with catheter directed thrombolysis when treating acute limb ischemia?
Speed of revascularization
CDT - much more gradual resolution
Open thrombectomy and PMT are much faster
Name clinical manifestation of atheromatous embolization - 7 different body parts/systems
1 - Skin: blue toe
2 - Eyes: hollenhorst plaque
3-Neuro- stroke/amarosis fugax
4-Cardiac - MI
5-GI - ischemic bowel/splenic infarcts
6-Renal - impairment
7-Constitutional: fever, weight loss, malaise
Name 3 risk prediction models for CLTI patients and their endpoints
- FINNVASC (30 d mortality and limb loss)
- PREVENT III (AFS at 1 year)
- BASIL (Survival at 2 years)
Name 4 critical factors identified in the FINNVASC score.
- DM
- CAD
- Gangrene
- Urgent operation
What are the wound stages in the WIFi classification?
0 - no ulcer
1 - small, shallow ulcer, no gangrene
2 - deeper ulcer w exposed bone, joint, tendon +/- gangrene
3 - extensive deep ulcer, full thickness heel ulcer +/- calcaneal involvement +/- extensive gangrene
What are the foot infection stages in the WIFi classification?
0 - no signs and symptoms of infection
1 - local skin/superficial infection
2 - local deeper than skin infection
3 - SIRS
What are the ischemia stages in the WIFi classification?
0 - ABI > 0.8, AP > 100, TP > 60
1 - ABI 0.6-0.8, AP 70-100, TP 40 - 60
2 - ABI 0.4-0.6, AP 50-70, TP 30-40
3 - ABI < 0.4, AP < 50, TP < 30
What are the wound stages in the WIFi classification?
0 - no ulcer
1 - small, shallow ulcer, no gangrene
2 - deeper ulcer w exposed bone, joint, tendon +/- gangrene
3 - extensive deep ulcer, full thickness heel ulcer +/- calcaneal involvement +/- extensive gangrene
What are the amputation rates of claudicants at 5 years?
1-7%
What is the annual mortality of claudicants
3-5% per year (As high as 12%)
How does cilostazol work? 4 beneficial effects?
Phosphodiesterase 3 inhibitor - increases cAMP resulting in:
1) Inhibition of smooth muscle contraction
2) Inhibition of platelet aggregation
3) Possibly decreases smooth muscle proliferation
4) Reduces serum triglycerides and increases HDL.
Which 2 drugs are FDA approved for claudication? Which is better?
Pentoxyfilline and cilostazol. RCT showed cilostazol increased maximal walking distance more than pentoxyfilline (which was similar to placebo group).
What are adverse side effects of cilostazol? What are contraindications?
Headache, diarrhea, GI discomfort.
Contraindication: CHF.
What is a TASC D aortoiliac lesion?
- Infrarenal aortoiliac occlusion
- Diffuse disease
- Multiple stenoses involving CIA, EIA and CFA
- Unilateral occlusions of both CIA and EIA
- Bilateral occlusions of eia
- Iliac stenoses in AAA pateints requiring open treatment
What is a TASC C aortoiliac lesion?
- Bilateral CIA occlusions
- Bilateral EIA stenoses up to 10 cm
- Unilateral EIA stenosis extending to CFA
- Unilateral EIA occlusion involving CFA/internal iliac origins
- Heavily calcified unilateral EIA occlusion
What is a TASC B aortoiliac lesion?
- Short stenosis of infrarenal aorta
- Unilateral CIA occlusion
- EIA stenoses up to 10 cm, not extending into CFA
- Unilateral EIA occlusion, not extending into internal iliac or CFA
What is a TASC A aortoiliac lesion?
Unlateral or bilat stenosis of CIA or < 3 cm EIA stenosis
What is a TASC D infrainguinal lesion?
- CTO of cfa or SFA > 20 cm involving pop
- CTO of popliteal or trifurcation
What is a TASC C infrainguinal lesion?
- Multiple lesions totalling > 15 cm
- Recurrent stenosis or occlusions that need treatment after 2 endo treatments
What is a TASC B infrainguinal lesion?
- Multiple lesions each < 5 cm
- Single stenosis or occlusion < 15 not involving pop
- Single/multiple lesions in absence of continuous tibial vessels
- Heavily calcified occlusion < 5 cm
- Single popliteal stenosis
What is a TASC A infrainguinal lesion?
- Single stenosis < 10 cm
- Single occlusion < 5 cm
Name 2 RCTs that compare medical therapy to endovascular therapy for claudication
- Edinburgh walking study
- CLEVER trial
What were the main outcomes of the CLEVER trial?
Claudicants with aortoiliac disease:
At 6 month follow up, change in peak walking time greatest in supervised exercise group, then stenting, worse for pharm treatment
QoL significantly improved in supervised exercise and stenting group compared with pharm
Which vessel supplies angiosome 2
Lateral calcaneal (peroneal artery)
Which vessel supplies angiosome 3
Showing plantar heel: Lateral calcaneal (peroneal)
Which vessel supplies angiosome 6
Lateral plantar artery (PT)
Which vessel supplies angiosome 5
Medial plantar artery (PT)
Which vessel supplies angiosome 4
Calcaneal branch (PT)
Which vessel supplies angiosome 1
Dorsalis pedis (AT)
How do you access the middle part of the profunda?
Dissect at the medial border of sartorius and retract laterally
How do you access the distal part of the profunda?
Dissect at the lateral border of sartorius and retract medially
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