Vascular Surgery - Quiz 3 Flashcards
Along with the other common risk factors, Elevated Homocystein & C-Reactive Protein are associated with which disease?
Peripheral Vascular Disease
What are symptoms of PVD?
Claudication
Skin Ulcers
Gangrene
Impotence
What are the mortality rates for PVD at 5 & 10 years?
5 years; 30%
10 years: 70%
How is PVD Treated?
Medications
Transluminal Angioplasty
Endartarectomy
Thrombectomy
Stenting
Arterial Bypass
What are the different Arterial Bypass procedures used to treat PVD?
Aorto-Fem
Axillo-Fem
Fem-Fem
Fem-Pop
Peripheral Vascular Occlusive disease may indicate what other areas that may be effected?
Coronary, Cerebral, and Renal Arteries
>50% of motality from PVD is due to PeriOperative Cardiac Events
What meds can be given d/t high risk of Cardiac Pathology related to PVD?
B-Blockers - decrease O2 demand and corrects O2 Supply-Demand mismatch
What is the primary monitoring objective when for Vascular Surgeries?
Detecting Myocardia Ischemia
Why is pain control important for Vascular Surgeries?
Pain greatly increases SNS stimulation - pain control improves comfort & cardiac stability
What are the Contributing Factors of Abdominal Aortic Aneurysms?
Atherosclerosis
HTN
Smoking
Genes
Obesity
Proteolysis of Elastin & Collagen of Vessel Walls
What are ways used to Diagnose an AAA?
Imaging
Contrast Studies
Digital Subtraction Angiography
When are Abdominal Aortic Aneurisms at the highest risk for rupturing?
Aneurysms > 5 cm
What are the AHA Pre-Operative guidelines for managing a patient w/ an AAA?
Glucose Control
Temperature Maintenance
Cardiac Optimization
What are the Renal Considerations regarding an AAA?
EVAR - stent migration
Contrast Exposure
Clamped Aorta alters Renal Hemodynamics
Hypotension & Perfusion
What is involved in an EVAR?
Guidewire thru Iliac artery to place a stent graft to restrict flow to the aneurysm. Sheath is deployed and hooks & barbs are placed to prevent stent migration
What meds are given before an EVAR?
Heparin 50-100 units/kg
&
ABX - 1st Gen. Cephalosporin
What are the Advantages of an EVAR?
↑Hemodynamic Stablity
↓Embolic Events
↓Blood Loss
↓Stress, Cortisol, Immune Response
↓Sepsis
↓Renal Dysfunction
↓Post Op Pain
What are the EVAR complications?
Graft Problems
Iliac Artery Rupture
Low Extremity Ischemia
Ischemic Gut
Endo Leak
What happens w/ the serious complication of an Endoleak?
Persistent blood flow & pressure b/t graft & aortic aneurysm
What are Type I & III Endoleaks?
Device Related
Type I: attachment site leak / perigraft channels
Type III: Graft Defect, Tear, Disconnection
Fix w/ second graft or open repair
What are Type II Endoleaks?
Collateral Retrograde Perfusion involving other Arteries
Spontaneously closes w/in first month
What is a Type IV Endoleak?
Holes in the Graft
Just observe patient
When is Surgical AAA Repair Contraindicated?
Recent MI
Intractable Angina
Severe Pulm. Dysfunction
Chronic Renal Insufficiency
What makes an AAA repair high risk?
> 85 y.o
Home O2
PaO2 < 50 mmHg
FEV1 < 1 L/s
Creatinine > 3 mg/dL
Severe CHF, CAD, EF < 30%, Ectopy, Angina
Which EKG leads should specifically be monitored for an AAA?
Lead II - Dysrythmias
Lead V5 - Ischemic ST Changes
What is the standard approach to an AAA Procedure?
Transperitoneal to expose infrarenal & iliac vessels as well as intraabdominal organs
Ends w/ rapid closure
What are the complications of the Transperitoneal approach for an AAA procedure?
Increased Fluid Loss
Prolonged Ileus
Post-Op Pain
Pulm. Complications
Mesenteric Traction Syndrome: Hypotension, Tachycardia, Facial Flushing, ↑CO
What are the advantages of a Retroperitoneal approach for an AAA Procedure?
Exposure to Justa/SupraRenal Aneurysm
↓Fluid Loss
↓Pain
↓Pulm. & GI Complications
No Mesenteric Traction Syndrome
What are the sites that Aortic Cross-Clamping can be?
Infrarenal - Most Common
Juxtarenal
Suprarenal
What are the risks associated with Higher Aortic Cross-Clamping?
Impact on CV System and Vital Organs d/t Hypoperfusion & Ischemia
What are the CV changes w/ Aortic Cross-Clamping?
HTN above Clamp
Hypotension Below Clamp
Blood Redistribution
No Distal Blood Flow
↓CO or No Change
↑PAOP or No Change
What drugs are normally used during Aortic Cross-Clamping?
Vasoactive Drugs
Nitroglycerin - ↓Preload & O2 Demand
Dopamine & Dobutamine - ↑CO
Nipride - ↓Afterload
Isolfurane - ↓SVR
What is the Neuroendrocrine response to Aortic Cross-Clamping?
Inflammation
↑Temp
Leukocytosis
Tachycardia
Tachypnea
Fluid Sequestration
Renal Failure may happen from Aortic Cross-Clamping, what can be given to prevent this?
Mannitol before Clamping
Dopamine
Lasix after Clap Removal
Fluids
How can Post-Op Paraplegia happen from an AAA Procedure?
Spinal Cord damage to the Adamkiewicz Artery / Radicular Artery from absence of collateral blood flow d/t higher clamp positions.
Maintain the MAP
Ischemia to which vessel can cause Ischemic Colon during an AAA repair?
Inferior Mesenteric Artery that supplies the Left Colon
What happens w/ Declamping Shock Syndrome?
Liberation of Anaerobic Metabolites
↓SVR
↓Venous Return
Reactive Hyperemia
↓Preload & Afterload
What is vital to providing circulatory stability before clamp release?
Volume loading Fluids to restore circulating volume to CVP by 3-5mmHg or PAOP by 3-4mmHg
What is the mortality rate for a Rupture AAA?
94%
Primary Objective - Hemodynamic stability & Fluid Resuscitation
Besides Abdominal, what are the other types of Aortic Aneurysms?
Thoracic Aortic
Aortic Dissection
Descending Thoracic
Thoracoabdominal
What causes a TIA or Stroke?
Abrupt decrease in Cerebral Blood Flow
How long does a TIA last?
Seconds to Minutes and can happen again after 24 hours
No loss of conciousness
Why are Carotid Endarterectomies performed on patients w/ TIAs?
>50% of strokes happen after a TIA
30% after 2 yrs & 55% after 12 yrs
What are the symptoms of a TIA w/ Vertebral Involvement?
Confusion
Dizziness
Vision Problems
What are the TIA symptoms when the Carotid is involved?
Unilateral Blindness or weakness
What can be used to Diagnose Cartoid Artery Stenosis?
Duplex Ultrasonography - Definity
Arteriography
CT
MRI
What contributes to poor surgical outcomes for a patient w/ CAD undergoing a CEA?
Myocardial Infarction more than stroke
What does a Positive Dipyridamol-Thallium imaging suggest?
Increased risk of adverse cardiac events
How does brain receive adequate blood flow when the carotid is clamped?
CPP is maintained by collateral blood flow
Cerebovascular Autoregulation
Shunt may also be placed
What EEG measurements may indicate neuro dysfunction?
Loss of Beta Waves
Loss of Amplitude
Emergence of Slow Waves
What Carotid stump pressures indicate neuro hypoperfusion?
Stump Pressures < 40-50 mmHg = neuro hypoperfusion
Needs shunt placed
At what MAP does CBF remain constant?
MAP of 60-160 mmHg
Chronic HTN shifts curve to the right, needing higher map to ensure adequare Cerebral Perfusion
What are PostOp considerations for CEA’s?
HTN
Carotid Hemorrhage
Neuro Decline
Cerebral Hyperperfusion Syndrome
What is the ACT requirement for Carotid Artery Stenting?
> 250 Seconds
Questionable safety and efficacy d/t increased stroke risk
Done under Local
