Transcript Post CABG coronary insufficiency
Post CABG coronary insufficiency: from prevention to intervention
By Ashraf Reda, M.D.
My deepest thanks to Hosam Mansour Marwa Ibrahim
CABG Modalities
• STANDARD CORONARY ARTERY BYPASS GRAFTING • BEATING HEART CORONARY ARTERY BYPASS GRAFT SURGERY • MID CABG WITHOUT CARDIOPULMONARY BYPASS
Internal mammary grafting consisting of an in situ left internal mammary artery (IMA) graft to the left anterior descending artery (end to side) and diagonal branch (side to side), with the diamond anastomotic technique used for the latter. The details show the IMA pedicle rolled up over the diagonal coronary artery to facilitate exposure and the use of continuous suture. (From Jones EL: Extended use of the internal mammary –coronary artery bypass
. J Card Surg 1:13, 1986. By permission of Futura Publishing Co.)
COMPLICATIONS OF CORONARY ARTERY BYPASS GRAFT SURGERY
• Aortic instrumentation and manipulation, including cannulation, decannulation, and partial or complete clamping and unclamping.
• Global cardiac arrest • Hypothermia • An intense "inflammatory" response to artificial perfusion • The sternotomy and skin incision
COMPLICATIONS OF CORONARY ARTERY BYPASS GRAFT SURGERY
• • Operative mortality 2-4% • Peri-operative myocardial infarction 2-4% Low cardiac output • Tachy-arrhythmias (AF in 40%} • Brady-arrhythmias • Bleeding(4-6% re-operation) • Neurological complications (2-4%) • Infection (mediastinitis 1% with 14% mortality) (14% in DM with bil. IMAs) • Acute renal failure (30% defined as a 50% + in S. cereat.) • Pleural effusion (90%) • Phrenic nerve damage (1%) • Intercostal nerve damage • Aortic dissection ( in1-4% a permanent pacing is required) • Thrombocytopenia (Limit post operative heparin) • Early readmission
Post CABG coronary insufficiency
• Recurrent Ischemia (17% @ 1 year) New disease in vessels not previously bypassed, Progressive disease in native vessels beyond the graft anastomosis, Disease in the bypass conduits themselves •
Vein graft failure:
8% at 1 year, 38% at 5 years and 75% at 10years.
Campeau L, et al, 1984.
Silent occlusion occurs in 28%, 32%, and 35% of SVG at 1-3, 4-6, and 7-11 • years after CABG respectively
Repeat Revascularsation:
Repeat CABG or PTCA is required in 4% of patients at 5 years, 19% of patients 10 years,and31% of patients 12 years after initial CABG .
Mark Freed, 1996
• Early
Graft occlusion
• Intermediate • Late
Graft occlusion passes in one out of three phases:
• Early occlusion: • Prior to discharge in 10% • Small vessel (1.5 mm) • Stenosis <70% • Technical factors, such as kinks from excessive length of the graft or poor distal artery run off
Graft occlusion passes in one out of three phases:
• Intermediate phase occlusion: 5 to 10 percent between one month and one year .
platelet aggregation, growth factor secretion, reduced endothelial production of nitric oxide and prostacyclin, reduced local fibrinolytic potential. Yang et al, 1998.
Graft occlusion passes in one out of three phases:
• Late occlusion: • After the first postoperative year • Intimal hyperplasia, lipid deposition and atherosclerotic plaque. • 2 percent per year from year2 to Yr 6, Then 4 to 5 percent per year. • Stenotic vein grafts to the left anterior descending (LAD) artery had two and five year survival rates of 70 and 50 percent compared to 97 and 80 percent for patients with native LAD stenoses. Lytle et al 1992 .
Mechanisms of Post CABG ischemia
• Thrombosis (Early) • Intimal hyperplasia (Intermediate) • Atherosclerosis (Late) • Coronary steal after internal mammary graft
insertion (IMA)
Subclavian stenosis
Un-ligated IMA branches
Radial artery conduit
• Less patency rates compared to IMA • Liability to spasm is a concern • Intra-operative papaverin, pre- and post operative Ca antagonists improve the outcome.
• Can be used as a free or a composite graft • Inferior epigastric artery to RCA and LCX is promising
PREDISPOSING FACTORS FOR POST CABG CORONARY INSUFFICIENCY
• Native Vessel Diameter • Grafted Vessel • Severity of Bypassed Proximal Stenosis • Age of Graft • Cigarette Smoking • Hyperlipidemia • Hypertension • Diabetes Mellitus • Effect of Gender
DIAGNOSIS OF POST CABG CORONARY INSUFFICIENCY
• Clinical and ECG evaluation: a normal resting ECG= normal LV function and good long term prognosis • Stress ECG (50-70% sensitivity & 80-90% specificity) • Radionuclide scintigraphy (higher sensitivity &specificity) • Multi-slice CT angiography • Coronary angiography
PREVENTION OF POST CABG CORONARY INSUFFICIENCY
Improved Vein Graft Preservation
• More effective anti-platelet therapy( early ASP + clopidogrel, Coumadin showed no benefit) • Intensive risk factor modification {statin-smoking cessation) • New therapeutic modalities ( gene, external stenting, GF modulation)
Alternatives to Vein Grafts
• Increasing use of arterial grafts • Recombinant techniques (PCI+CABG)
Fig.2: PERCENTAGE OF DISEASED GRAFTS
100 90 80 70 60
%
50 40 30 20 10 0 LIMA RIMA
GRAFTS
Radial SVG
Fig.4. PATIENT OUTCOME
60 50 40
%
30 20 10 0 PTCA Redo CABG
OUTCOME
Medical treatment
Causes of ischemia in the IMA territory:
• Significant atheroma distal to the anastomotic site.
• At the anastomotic site (intimal hyperplasia, technical error) • Subclavian stenosis proximally • Large un-ligated branch of IMA • PCI is usually effective
MANAGEMENT OF POST CABG CORONARY INSUFFICIENCY
• IMA anastomotic site: balloon • IMA elsewhere: stent • SVG: ????????
PCI restenosis is 40-70% Redo CABG is risky Try not to use them
Guidelines and recommendations
• Class I indications: • Early postoperative ischemia (within30 days) • Class II indications • 1-3 Yrs- discrete graft lesion- preserved LV function • Disabling AP in native circulation • >3 years diseased venous grafts • Class III indications • PCI to chronic total VG occlusion • Multi vessel disease, multiple SVG failure and poor LV function
PCI in venous grafts
• Early is better than late • High thrombotic burden (recent VG with focal lesion is favorable yet with high re-stenosis rate around 25% with stents) • Distal protection is an option (Percu-Surge Guard-Wire) • Covered stents • Atherectomy devices • Catheter thrombectomy • Ultrasound thrombectomy
Trans-myocardial Revascularization (TMR)
The concept emerged from what was determined hearts were not nourished from sinusoidal connections to the ventricular chamber as were reptilian hearts. Wearns et al., 1933. The early clinical trials suggest that angina relief is excellent, averaging two angina classes of
Remember
Leave asymptomatic patients alone
Remember
If it’s CABG use arterial grafts
CardioLipid 2006
9th Annual Lipid Day &Interactive Cardiology Course 1st Annual meeting of the working group for Lipidology, Vascular biology and Research
20:45- 21:00
: Post CABG intervention: Case I Mohamed Ashraf
21:00- 21:15:
Post CABG intervention Case II
21:15- 21:30:
Case III
21:30: 21:45
: Post CABG intervention: are there any guide lines Hosam Mansour Ihab Abdelfatah Hosam Kandil
16-18 November 2006 Stella DeMary ElSokhna