Surgery : Cardiac Surgery Flashcards
Indications for CABG
CAD that is refractory to med treatments Unstable angina Chronic Angina Symptomatic/Complicated MI Triple Vessel Disease Diabetes with 2 Vessel Disease
Gold standard for diagnosing extent of CAD and latency of vessels ?
PCI Angiography (allows for simultaneous treatment by placing a stent )
What are the two main type of grafts used in CABG
Saphenous Vein
Internal Mammary Artery (thoracic)
Saphenous vein grafts typically are used to connect which two structures ?
Aorta and Right Coronary Artery
Internal Mammary Artery grafts connect which two structures ?
Subclavian (via root of IMA) and the Left Anterior Descending Artery (Left Internal Mammary artery is used )
Patency rate of Saphenous grafts at 10 yrs
50% occlusion at 10 years
Patency rate of LIMA grafts at 10 yrs
95%
When patient has good LV function, No comorbidities and is less than 80%, what is the mortality rate for CABG graft with these patients ?
1-2%
Risk factors for morbidity and mortality related to CABG graft surgery
Age (>80) COPD PVD Previous open heart surgery Renal Insufficiency (if kidneys were shot beforehand, not really going to make a difference ) LV dysfunction Recent MI < 90 days
How long after surgery until the patient will be up and walking ?
first 24 hrs !
ICU admission x at least 24 hours Intubated Chest tube Pacemaker electrodes Average total LOS 5 days Out of bed and walking post op day one Discharge home ASAP
Traditional CABG
Sternotomy incision
Heart is STOPPED
Bypass machine with blood HEPARINIZED
Still the most common procedure
Off Pump CABG
Sternotomy incision Performed on a beating heart No bypass machine, no heparin required Better results , fewer complications Takes longer, not appropriate for complex procedures Not yet universally available
Minimally Invasive Direct Coronary Artery Bypass (MIDCAB)
Small left side incision
Performed on beating heart
No bypass machine, no heparin
Limited to anterior surface of the heart – LIMA to LAD**
Takes longer, not appropriate for complex procedures
Not yet universally available
Total endoscopic coronary artery bypass
Still in development Endoscopic instruments through tiny incisions Requires robotic equipment Beating or non beating heart You know the rest
Prevalence of Atrial Fib. post CABG and Valve replacement respectively ?
25% 50% Even when treated with Beta Blockers Continue to treat with BB or CCB's If A Fib goes on for 48 Hrs then anti-coagulate. (most resolve within 24 hrs)
RIsk factors for post op A.fib ?
Age
HTN
Increased time on Ventilation
Valve Replacement due to Aortic Stenosis: What 4 classes of Aortic stenosis are there ?
Congenital
Calcific (age related)
Endocarditis
Rheumatic
Symptoms associated with Stenotic Aoritic Valve
CHF
Syncope
Angina
Critical valve area .5cm2
Causes of Aortic Vavle Regurgitation
Rheumatic
Endocarditis
Aortic root disease –> dilation
Seen in Marfans and Syphilis.
Mechanical Aortic Valves
St. Jude is most common
Last very long time
Patient must be anticoagulated for rest of life
Contraindicated in cerebral and GI bleeds due to need for anti-coagulation
Bioprosthetic Aortic Valves
Porcine
Bovine
Cadaveric Homograft
Last 10-15 yrs
Do not require anti-coagulation
What Valve: Young healthy patient ?
Mechanical
What Valve: Elderly with multiple health problems
BP since it will last 10 years and will not need anti-coagulation
What Valve: Woman of child bearing years
Bioprosthetic since we cannot anti-coagulate this patients properly
What Valve: Patient With A-fib
Mechanical, will need to be anti-coagulated anyhow
Treatment of Mitral Vavle Stenosis
Percutaneous balloon valvuloplasty
Open mitral commissurotomy
Mitral valve replacement
Esp. if pulm. HTN***
Multi-valve disease
Aortic + Mitral
Mitral + Tricuspid
Triple valve disease
Excellent results in elderly and high risk patients
Valve replacement is very rarely denied unless the only option is transplant