peripheral-vascular-disease-surgical-presentation

Peripheral Vascular Disease Acute & Chronic Limb Ischemia

Lipi Shukla

What is PVD?

Definition: . Definition: Sudden occlusion of an artery is commonly due to either emboli or trauma & it may also happen when thrombosis occur on plaque pre-existing atheroma. Occlusive disease of the arteries of the lower extremity. Most common cause: Atherothrombosis Others: arteritis, aneurysm + embolism. Has both ACUTE and CHRONIC Px

Pathophysiology:Arterial narrowing  Decreased blood flow = Pain Pain results from an imbalance between supply and demand of blood flow that fails to satisfy ongoing metabolic requirements.

The Facts:

The prevalence: >55 years is 20%2. 70%–80% of affected individuals are asymptomatic3. Pt’s with PVD alone have the same relative risk of death from cardiovascular causes as those CAD or CVD 4. PVD pt’s = 4X more likely to die within 10 years than pt’s without the disease.5. The ankle–brachial pressure index (ABPI) is a simple, non-invasive bedside tool for diagnosing PAD — an ABPI <0.9 = diagnostic for PAD6. Patients with PAD require medical management to prevent future coronary and cerebral vascular events.7. Prognosis at 1 yr in patient’s with Critical Limb Ischemia (rest pain): Alive with two limbs — 50%Amputation — 25%Cardiovascular mortality 25%

Risk Factors:

Typical Patient: Smoker (2.5-3x) Diabetic (3-4x) Hypertension Hx of Hypercholesterolemia/AF/IHD/CVA

Age ≥ 70 years.Age 50 - 69 years with a history of smoking or diabetes.Age 40 - 49 with diabetes and at least one other risk factor for atherosclerosis. Leg symptoms suggestive of claudication with exertion or ischemic pain at rest.Abnormal lower extremity pulse examination.Known atherosclerosis at other sites (eg, coronary, carotid, or renal artery disease).

Factors influencing the clinical manifestations of peripheral arterial disease

1- Anatomical site Cerebral circulation Renal arteries Mesenteric arteries Limbs (legs [Gt ] arms) 2- Collateral supply 3- Speed of onset 4- Mechanism of injury Haemodynamic Thrombotic Atheroembolic Thromboembolic


Chronic lower limb arterial disease

Intermittent claudication (IC) 

Derived from the latin word ( to limp ) ischaemic pain affecting the muscles of the leg upon walking. claudication distance

5% of middle-aged men report IC

only 1-2% per year amputation and/or revascularisation is required

annual mortality rate >5%( 2-3 times higher than in non-claudicant)

Claudication vs. Pseudoclaudication
Claudication
Pseudoclaudication
Characteristic of discomfort
Cramping, tightness, aching, fatigue
Same as claudication plus tingling, burning, numbness
Location of discomfort
Buttock, hip, thigh, calf, foot
Same as claudication
Exercise-induced
Yes
Variable
Distance
Consistent
Variable
Occurs with standing
No
Yes
Action for relief
Stand
Sit, change position
Time to relief
<5 minutes
30 minutes Also see Table 4 of Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192.


Physical Examination:
Examination:
What do to:
Inspection Expose the skin and look for:
Thick Shiny Skin Hair Loss Brittle Nails Colour Changes (pallor) Ulcers Muscle Wasting
Palpation
Temperature (cool, bilateral/unilateral) Pulses: ?Regular, ?AAA Capillary Refill Sensation/Movement
Auscultation
Femoral Bruits
Ankle Brachial Index (ABI)
= Systolic BP in ankle Systolic BP in brachial artery
Buerger’s Test

Pictures:

DDx of Leg Pain
Vascular DVT (as for risk factors) PVD (claudication) Neurospinal Disc Disease Spinal Stenosis (Pseudoclaudication) Neuropathic Diabetes Chronic EtOH abuse Musculoskeletal OA (variation with weather + time of day) Chronic compartment syndrome

What does the ABI mean?

ABI
Clinical Correlation
>0.9
Normal Limb
0.5-0.9
Intermittent Claudication
<0.4
Rest Pain
<0.15
Gangrene
CAUTION: Patient’s with Diabetes + Renal Failure:They have calcified arterial walls which can falsely elevate their ABI.


Understanding the ABI
The ratio of the higher brachial systolic pressure and the higher ankle systolic pressure for each leg:
Ankle systolic pressure Higher brachial artery systolic pressure
ABI =

Interpreting the Ankle-Brachial Index

Adapted from Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192. Figure 6.
ABI
Interpretation
1.00–1.29 Normal
0.91–0.99 Borderline
0.41–0.90 Mild-to-moderate disease
≤0.40 Severe disease
≥1.30 Noncompressible

ABI Limitations

Incompressible arteries (elderly patients, patients with diabetes, renal failure, etc.) Resting ABI may be insensitive for detecting mild aorto-iliac occlusive disease Not designed to define degree of functional limitation Normal resting values in symptomatic patients may become abnormal after exercise



Toe-Brachial Index Measurement
The toe-brachial index (TBI) is calculated by dividing the toe pressure by the higher of the two brachial pressures.TBI values remain accurate when ABI values are not possible due to non-compressible pedal pulses.TBI values ≤ 0.7 are usually considered diagnostic for lower extremity PAD.

Exercise ABI Testing

Confirms the PAD diagnosisAssesses the functional severity of claudicationMay “unmask” PAD when resting ABI is normalAids differentiation of intermittent claudication vs. pseudoclaudication diagnoses

Critical limb ischaemia (CLI)

defined as rest (night) pain, requiring opiate analgesia, and/or tissue loss (ulceration or gangrene), present for more than 2 weeks, in the presence of an ankle BP of < 50 mmHg. Rest pain only, with ankle pressures > 50 mmHg, is known as subcritical limb ischaemia (SCLI). The term severe limb ischaemia (SLI) is used to describe both CLI and SCLI

Investigations:

NON INVASIVE:Duplex Ultrasound normal is triphasic  biphasic  monophasic  absent BLOOD TESTS: FBE/EUC/Homocysteine Levels Coagulation Studies Fasting Lipids and Fasting Glucose HBA1C
WHEN TO IMAGE:To image = to intervenePt’s with disabling symptoms where revascularisation is consideredTo accurately depict anatomy of stenosis and plan for PCI or SurgerySometimes in pt’s with discrepancy in hx and clinical findings

ANGIOGRAPHY:Non-invasive:CT AngiogramMR Angiogram Invasive:Digital Subtraction Angiography  Gold Standard Intervention at the same time

Tardus et parvus = small amplitude + slow rising pulse

CT Angiography Digital Subtraction Angiography
Value of angiography Localizes the obstruction Visualize the arterial tree & distal run-off Can diagnose an embolus: Sharp cutoff, reversed meniscus or clot silhouette

Treatment:

1. RISK FACTOR MODIFICATION: Smoking Cessation Rigorous BSL control BP reduction Lipid Lowering Therapy
3. MEDICAL MANAGEMENT: Antiplatelet therapy e.g. Aspirin/Clopidogrel Phosphodiesterase Inhibitor e.g. Cilostazol Foot Care
2. EXERCISE: Claudication exercise rehabilitation program 45-60mins 3x weekly for 12 weeks

PTA/Surgery:

Indications/Considerations:Poor response to exercise rehabilitation + pharmacologic therapy.Significantly disabled by claudication, poor QOLThe patient is able to benefit from an improvement in claudicationThe individual’s anticipated natural hx and prognosisMorphology of the lesion (low risk + high probabilty of operation success)PTA:Angioplasty and StentingShould be offered first to patients with significant comorbidities who are not expected to live more than 1-2 yearsBypass Surgery:Reverse the saphenous vein for femoro-popliteal bypassSynthetic prosthesis for aorto-iliac or ilio-femoral bypassOthers = iliac endarterectomy & thrombolysisCurrent Cochrane review = not enough evidence for Bypass>PCIAmputation: Last Resort

What are the features of an acute ischemic limb?

REMEMBER THE 6 P’S:PAIN2. PALLOR3. PULSELESNESS4. PERISHING COLD (POIKILOTHERMIA)5. PARASTHESIAS6. PARALYSIS Fixed mottling & cyanosis

What will you do now?

1. CALL THE VASCULAR SURGEON OR INTERVENTIONALIST
2. ORDER INVESTIGATIONS FBE EUC Coagulation Studies Group and Hold 12 Lead ECG Chest XR
3.INITATE ACUTE MANAGEMENT:AnalgesiaCommence IV heparinCall Radiology for Angiography if limb still viableDiscuss for :Thrombotic cause  ?cathetar induced thrombolysisEmbolic cause  ?embolectomyAll other measures not possible  Bypass/Amputation Simple measures to improve existing perfusion: Keep the foot dependant Avoid pressure over the heel Avoid extremes of temperature (cold induces vasospasm) Maximum tissue oxygenation (oxygen inhalation) Correct hypotension

Questions?