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Myocardial revascularisation using radial artery presentation
- 1. بسم ا الرحمن الرحيم
- 2. Myocardial Revascularization Using the Radial Artery: Midterm Results Anas Abdel Azim, Tamer Farouk , Wagih Al-boriey , Magdy Gomaa Cardiothoracic surgery department, Faculty of Medicine, Cairo University
- 3. Background Although CABG is a well-established therapy for advanced CAD, late benefits are influenced by the fate of the bypass conduit used. Formerly SVG were solely used. The development of vein graft atherosclerosis along with the unparalled patency results of LIMA grafts encouraged the search for other arterial grafts.
- 4. Background The radial artery (RA) was first introduced into clinical practice by Carpentier and associates in 1971. Two year later, Carpentier abandoned its use because of severe diffuse narrowing that occurred in 35% of the grafts.
- 5. Background In 1992, Acar and colleagues revived the use of RA in CABG after unexpected finding that some of the RA graft in the early series of Carpentier are still patent 14-18 years later Favorable results due to modified surgical technique avoiding skeletonization and excessive dilatation, along with development of vasodilator agents.
- 6. Advantages of RA • An arterial graft that is adapted to arterial blood pressure with no added risk of sternal devascularization • Homogenous caliber, free from internal valves. • Sufficient Length • Harvested simultaneously with other conduits. • Available in Redo cases.
- 7. Contraindications to RA Use Inadequate ulnar collateral circulation. Diffuse atherosclerosis or medial calcification. Previous trauma or surgery in the forearm. Previous RA cannulation. A-V fistula for hemodialysis. Vasculitis and Raynaud’s disease. Impaired LV function. Old age.
- 8. Pathologic Changes of the RA Compared to IMA, the RA has a thicker muscular wall, less elastic tissue and fenestrated internal elastic, making the RA more prone to atherosclerosis. • 5% of RAs Vs 0.7% of IMAs. • overall severity of pathological changes in the RA is low. Risk factors for RA atherosclerosis: age, male gender, smoking, diabetes, hypertension and PVD. Medical calcification occur in 6% of RAs and is often mild; more common in: old age, diabetes and CRF.
- 9. RA Spasm RA is classified as type III or limb artery: high propensity to spasm (thick muscular wall). The vasoreactivity of RA grafts is highest in the first 3 months Use of antispasmodic drugs seems mandatory; either • topically: papaverine, VG solution, Milrinone and phenoxybenzamine • systemically: Ca++ channel blockers (e.g. verapamil, diltiazem) or nitroglycerine. Long-term Ca++ channel block therapy is controversial.
- 10. A B (A) Cineangiography showing the radial artery graft vasospasm (arrows) emerging of the left internal mammary artery anastomosed to a lateral branch of the left circumflex artery. (B) Cineangiography after intravenous nitroglycerine administration showing resolution of the artery graft vasospasm.
- 11. Assessment of Adequate Hand Circulation It is mandatory to assess adequacy of ulnar collateral circulation of the hand before RA harvest. Inadequate ulnar collateral circulation excludes RA harvest unilaterally in 5-11% of patient and bilaterally in 5-6% of patients Assessment methods: • Modified Allen’s test • Duplex scanning (with dynamic testing)
- 12. Forearm Complications Following RA Harvesting Remains as a source of concern to surgeons. Incidence of local complications is about 5%, including: • Hematoma, • Seroma, • Local swelling • Hand ischemia • Neurologic manifestations
- 13. Forearm Complications Following RA Harvesting Neurologic manifestations (parasthesias, numbness, sensory loss) are the commonest: 9%-49%. The majority of these manifestations are mild and self-limiting. Incidence of wound infection is much lower than GSV harvest site (6% Vs 15%).
- 14. Grafting Strategy Factors affecting RA graft patency: • Target vessel stenosis: the higher the stenosis, the better the RA graft patency. • Target vessel location: RA grafts to RCA territory have lower patency. • Target vessel size. • Target vessel quality. Proximal RA anastomosis: Aortic anastomosis or composite grafting? Sequential grafting and composite grafting possible with the use of RA grafts to achieve total arterial myocardial revascularization .
- 15. Aim of study The aim of this study is to review current knowledge regarding the use of RA in CABG as well as to evaluate the safety and efficacy of this graft in CABG surgery on Midterm basis.
- 16. Patients and Methods Patient Population & Follow-up • Between January 2005 and December 2007, 50 patients underwent Primary isolated CABG surgery using the RA as one of the bypass conduits • In all patients, LAD was exclusively bypassed using LIMA, while RA was used to bypass the next largest territory. Revascularization was completed by GSV if necessary • Patients were followed up throughout the durations of their hospital stay and for at least 2 years thereafter
- 17. Patients and Methods General exclusion criteria: • Patients >65 years. • Emergency CABG. • Redo CABG. • Patients undergoing concomitant valve procedure, LV procedure or another vascular/general surgical procedure. Specific contraindications for RA use: • Previous trauma or surgery to forearm. • A-V fistula for hemodialysis. • Radial dependent hand circulation. • Raynaud’s disease. • Subclavian artery disease
- 18. Preoperative Assessment Routine medical history and detailed clinical examination: with emphasis on preoperative risk factors (smoking, obesity, hyperlipidemia, diabetes, …etc), previous MI. Routine panel of preoperative studies: • Laboratory tests (CBC, coagulation profile, liver and kidney functions). • 12-lead resting ECG. • Plain chest x-ray. • Echocardiography. • Coronary angiography. • Myocardial perfusion scintigraphy, if indicated. • Duplex scanning of the carotid and radial arteries as well as the lower limb veins. Preoperative assessment of hand circulation is done via Modefied Allen’s test (with the cut-off point for positive test at 10 seconds) along with duplex scanning of the radial arteries.
- 19. Operative strategy RA harvesting: • RA harvesting as a pedicle graft using low-energy electrocautery and hemoclips • VG solution was used to flush the RA after harvesting without distension • Fascia overlying the RA was not opened except at the anastomotic points • Before skin incision low-dose verapamil infusion was started (0.5 mg/h) to guard against RA spasm • Forearm wound is closed in 2 layers on a small suction drain
- 20. Operative strategy Surgical technique: • Median sternotomy, on cardiopulmonary bypass with warm antegrade cardioplegic arrest • LIMA was exclusively used to bypass LAD while RA was grafted to next largest myocardial territory • All RA grafts were used to bypass coronary arteries with critical (>90%) stenosis • Proximal RA anastomosis was placed on LIMA as a T- or Y-graft on cross-clamp
- 21. Early postoperative follow up: • Period of mechanical ventilation. • Inotropic support • Use of IABP • Peak CK-MB level • Incidence of major complications: Low cardiac output syndrome Postoperative myocardial ischaemia Graft spasm Re-exploration for bleeding and the need for blood transfusion. Neurologic dysfunction. Renal impairment. Chest infection and respiratory failure. Sternal wound infection. RA harvest site complications. • Duration of ICU stay. • Duration of hospital stay. • In-hospital mortality.
- 22. Late follow up: • Cardiac Adverse events: Myocardial infarction recurrent angina Clinically-significant arrhythmias Hospitalization for cardiac cause Coronary re-intervention (PCI or CABG). • Mortality and event-free survival • Forearm and hand complications
- 23. RESULTS
- 24. Preoperative patient characteristics No. of patients 50 Clinical characteristics: Age (years) 52.5±7.3 (40-65 ) Female 10 (20%) Coronary risk factors: Hypertension 10 (20%) Diabetes 30 (60%) Hyperlipidemia 38 (76%) Smoking 40 (80%) Obesity 20 (40%) Family history 6 (12%) Co-morbidity: CVD 3 (6%) PVD 4 (8%) COPD 6 (12%)
- 25. Preoperative cardiac profile of study patients Cardiac profile: Previous MI: 30 (60%) EF: >50% 38 (76%) <50% 12 (24%) CCS: I 5 (10%) II 10 (20%) III 30 (60%) IV 5 (10%) Angiographic profile: 2-vessel disease 14 (28%) 3-vessel disease 29 (58%) Lt main disease 7 (14%) Previous angioplasty 12 (25%)
- 26. Distribution of coronary risk factors in the study group 40 35 30 25 20 15 10 5 0 Fa H O D S H m yp ia yp be m be ok er er si iy te in ty te lip hi s g ns id st io or em n y ia
- 27. Operative Results Total operative time (minutes) 319.90 ± 76.9 Total bypass time (minutes) 102.2 ± 29.5 Total aortic cross-clamp time (minutes) 67.8 ± 21.4 RA harvest time (minutes) 35.0 ± 2.8 Total No. of distal anastomosis 157 No. of distal anastomosis per patient 3.14 (2-5) Total No. of LIMA anastomoses 50/157 (31.8%) Total No. of arterial anastomoses 120/157 (76.3%) No. of patients with total arterial revascularization 15/50 (30%) Total No. of GSV graft distal anastomoses 37/157 (23.7%)
- 28. Patterns of RA grafting in study patients Total No. of distal RA anastomoses 70/157 (44.5%) No. of separate RA grafts 32/50 (64%) No. of sequential RA grafts 18/50 (36%) Target site of the RA grafts: - Lt anterior descending artery 0/70 (0%) - Diagonal branches 14/70 (20%) - Obtuse marginal branches 36/70 (51.4%) - Posterior descending artery 13/70 (18.5%) - Posterolateral artery 2/70 (2.8%) - Ramus 5/70 (7.1%)
- 29. Distribution of the radial artery grafts to the different coronary arteries [OM: obtuse marginal branches; PDA: posterior descending artery] 40 35 30 25 No. of Anastomoses 20 15 10 5 0 R P P D O am os D ia M A g t us er on ol a lb at er ra al n ch ar e te s r Vessel grafted y
- 30. Postoperative morbidity and mortality In-hospital mortality 1 (2%) ICU stay (hours) 75 ± 9.1 hours Hospital stay (days) 11 ± 2.4 days Mechanical ventilation (hours) 8.5 ± 1.2 hours Inotropic support (dose of adrenaline) 0.03 ± 0.045 µg/Kg/min IABP support 2 (4%) Mean CK-MB level (IU/L) 13.2 ± 11.6 IU/L Postoperative MI 1 (2%) Postoperative ischaemia 2 (4%) Re-exploration for bleeding 2 (4%) Transfusion requirements: - Packed RBCs (units) 4.3 ± 1.8 units - Fresh frozen plasma (units) 8.5 ± 4.9 units - Platelets (units) 6.6 ± 1.7 units RA harvest site complications: - Hand ischaemia - - Paresthesias 18 (36%) - Hand swelling 10 (20%) - Hematoma 1 (2%) - Forearm wound infection - - Functional impairment - Sternal wound infection 2 (4%) Acute renal failure 1 (2%) Cerebrovascular accident -
- 31. Midterm Results Follow-up completed for 84%(85.7%) of patients Mean follow-up period=2.5±0.4 years Angiographic follow-up available for 7 patients (14.3%)
- 32. Midterm Results Cardiac Adverse events: • Myocardial infarction 4.7%(2) • recurrent angina 9.5%(4) • Clinically-significant arrhythmias 4.7%(2) • Coronary re-intervention 2.3%(1) • Hospitalization for cardiac cause 21.4%(9)
- 33. Midterm Results Repeat angiography: • Average time to repeat angiography: 28.5 months • Total RA grafts/anastomoses studied: 7/13 • Patency rate for the studied RA grafts: 100% Survival: • Midterm survival: 95.2% (40/42) • Overall survival: 93% (40/43)
- 37. Discussion In spite of mounting evidence that multiple arterial grafts improve outcome in CABG, some surgeons worldwide are still reluctant to adopt total arterial revascularization (TAR) TAR is associated with several concerns: • Is it safe? • Which arterial conduit to use preferentially after LIMA: RIMA or RA?
- 38. Discussion 4 randomized trial to evaluate role of RA in CABG Long-term results of RA graft patency and survival compared with SV graft remains controversial in randomized controlled trials, probably because both the incidence of flow competition and the varied definition of graft patency
- 39. RA grafting Randomized Trials N Follow- Angiographic patency Design up RAPS 561 1 RA= 91.8% RA or SV to the (2004) year SV=86.4% next important territory after LAD RSVP 142 5 RA=98.3% RA or SV to LCx (2008) years SV=86.4% territory RAPCO 394 5.5 RAvsRIMA=89%vs83% RA vs SV>70y (2010) 225 years RAvsSV=90%vs87% RA vs RIMA<70y VA Study 757 1 RA=89% RA or SV to the (2011) year SV=89% next important territory after LAD
- 40. Conclusion In the current study, we tried to answer the question: • Is the use of RA grafts in CABG is safe and effective on midterm basis? Based on the results of this study, which comes in accordance with others, the use of RA seems to be safe, reproducible and does not compromise operative and midterm outcomes of CABG surgery