**7. Results**

• **Unsatisfactory quality of life**—even though unsatisfactory quality of life after CABG is one of the most important unfavorable outcome events, quantifying it is very difficult because it depends on the following three factors:

2.A parallel configuration in which the graft and target coronary axes are aligned

• The side-to-side anastomoses used in SB are technically difficult

• Interrupted crossed side-to-side anastomosis greatly simplifies this

In an experimental study with animals, Shioi [22] compared various techniques for performing anastomoses, reporting that crossed side-to-side anastomosis enabled a larger opening than did parallel side-to-side anastomosis and that interrupted sutures enabled a larger anastomotic opening than did a continuous suture.

• **Early death**—in general, after isolated CABG, approximately 98% of patients survive at least 1 month, and 97, 92, 81, and 66% survive 1, 5, 10, and 15 years or more, respectively. In an analysis of seven large datasets representing more than 172,000 patients, Jones and colleagues identified seven variables most

(parallel side-to-side anastomosis) (**Figure 16**)

*The Current Perspectives on Coronary Artery Bypass Grafting*

procedure.

predictive of early mortality [23]:

**6.8 Complications**

**Figure 16.**

*Parallel side-to-side anastomosis.*

◦ Older age

**100**

◦ Female gender

◦ Previous CABG

• Continuous or interrupted sutures can be used.

compared with regular end-to-side anastomoses.


patency rates are approximately 95% at 10 years after operation, and closure of the mammary artery after that time is uncommon. This favorable performance

descending coronary artery is probably due to its particular wall structure and function and the potentially large runoff through the left anterior descending artery system. Internal mammary artery grafts to other vessels appear to have lower patency rates late postoperatively than do those to the left anterior descending artery, and these may be no greater than those of vein grafts [45]. IMA as a free graft from the aorta to LAD provides patency almost as high as

of the internal mammary artery when anastomosed to the left anterior

*Coronary Artery Bypass Grafting: Surgical Anastomosis: Tips and Tricks*

*DOI: http://dx.doi.org/10.5772/intechopen.88932*

• **Other arterial grafts**—early (<13 months) patency of radial artery grafts exceeds 90% and does not differ from ITA patency [46]. A native coronary stenosis of less than 70% is associated with lower patency of a radial artery graft than if the stenosis is 70% or greater. Tatoulis and colleagues [47], in a study of long-term patency of 1108 radial artery grafts, reported patency of 89% at a mean follow-up interval of 48 months. Of 318 grafts in place for more than 5 years, 294 (92%) were patent. Of 107 in place for more than 7 years, 99 (92%) were patent. Patency was highest for grafts placed to the LAD (96%)

In a study by Suma and colleagues [48] of gastroepiploic artery grafts in 685 patients who underwent postoperative angiographic evaluation, patency was 94% within 1 year in all 685 patients, 88% between 1 and 5 years in 102 patients and 83% between 5 and 10 years in 102 patients. Time-related patency at 1 month, 1 year, 5 years, and 10 years was 96, 91, 80, and 62%, respectively. The principal causes of late occlusion were anastomotic stenoses and anastomoses to less critically stenosed

For the inferior epigastric artery, Gurne and colleagues [49] performed postoperative angiography in 122 patients early (11 5 days) and in 72 patients late (11 6 months) after operation. Early patency was 98%, and late patency was 93%. Of 14 grafts that were occluded or threadlike at the late study, 8 were anastomosed

• **Saphenous vein grafts**—diffuse intimal hyperplasia is a universal finding in vein grafts that have been in place for more than 1 month [50]. Thickness of the intimal hyperplasia seems to be inversely related to flow in the graft, and the process appears to result in a matching of vein lumen size to that of the coronary arteries supplied by the graft. About 10% of vein grafts get closed within the first few postoperative weeks. By 10 years after insertion, half of vein grafts still patent have undergone at least some arteriosclerotic changes [51]. About 20% of vein grafts have proximal suture line stenosis within 1 year; about one fourth of these are found to be occluded 5 years later. Almost 50% of patients have some narrowing of the distal anastomosis within 1 year, but most have not progressed by 5 years after CABG. The 10-year patency rate of vein grafts appears to be highly variable, and in some reports [52] only 50–60% overall are still patent. Arm veins have a still lower prevalence of patency [53] as do synthetic conduits. The patency rates are lower when the anastomosis is to small coronary arteries and to arteries supplying areas with considerable scar. Thrombosis, another process that can reduce graft patency, may develop early postoperatively. Endothelial cell loss and exposure of the basement membrane and collagen to blood tend to appear early after inserting the vein graft, predisposing it to early

accumulation of platelets, fibrin, and thrombus on its luminal surface.

with an in situ graft.

coronary arteries.

**103**

and lowest for grafts to the RCA (83%).

to arteries with a stenosis of 60% or less.

3.Preservation of exercise capacity.

Most of the patients have a satisfactory quality of life early after CABG, but this gradually begins to decline after about 5 years [34].


patency rates are approximately 95% at 10 years after operation, and closure of the mammary artery after that time is uncommon. This favorable performance of the internal mammary artery when anastomosed to the left anterior descending coronary artery is probably due to its particular wall structure and function and the potentially large runoff through the left anterior descending artery system. Internal mammary artery grafts to other vessels appear to have lower patency rates late postoperatively than do those to the left anterior descending artery, and these may be no greater than those of vein grafts [45]. IMA as a free graft from the aorta to LAD provides patency almost as high as with an in situ graft.

• **Other arterial grafts**—early (<13 months) patency of radial artery grafts exceeds 90% and does not differ from ITA patency [46]. A native coronary stenosis of less than 70% is associated with lower patency of a radial artery graft than if the stenosis is 70% or greater. Tatoulis and colleagues [47], in a study of long-term patency of 1108 radial artery grafts, reported patency of 89% at a mean follow-up interval of 48 months. Of 318 grafts in place for more than 5 years, 294 (92%) were patent. Of 107 in place for more than 7 years, 99 (92%) were patent. Patency was highest for grafts placed to the LAD (96%) and lowest for grafts to the RCA (83%).

In a study by Suma and colleagues [48] of gastroepiploic artery grafts in 685 patients who underwent postoperative angiographic evaluation, patency was 94% within 1 year in all 685 patients, 88% between 1 and 5 years in 102 patients and 83% between 5 and 10 years in 102 patients. Time-related patency at 1 month, 1 year, 5 years, and 10 years was 96, 91, 80, and 62%, respectively. The principal causes of late occlusion were anastomotic stenoses and anastomoses to less critically stenosed coronary arteries.

For the inferior epigastric artery, Gurne and colleagues [49] performed postoperative angiography in 122 patients early (11 5 days) and in 72 patients late (11 6 months) after operation. Early patency was 98%, and late patency was 93%. Of 14 grafts that were occluded or threadlike at the late study, 8 were anastomosed to arteries with a stenosis of 60% or less.

• **Saphenous vein grafts**—diffuse intimal hyperplasia is a universal finding in vein grafts that have been in place for more than 1 month [50]. Thickness of the intimal hyperplasia seems to be inversely related to flow in the graft, and the process appears to result in a matching of vein lumen size to that of the coronary arteries supplied by the graft. About 10% of vein grafts get closed within the first few postoperative weeks. By 10 years after insertion, half of vein grafts still patent have undergone at least some arteriosclerotic changes [51]. About 20% of vein grafts have proximal suture line stenosis within 1 year; about one fourth of these are found to be occluded 5 years later. Almost 50% of patients have some narrowing of the distal anastomosis within 1 year, but most have not progressed by 5 years after CABG. The 10-year patency rate of vein grafts appears to be highly variable, and in some reports [52] only 50–60% overall are still patent. Arm veins have a still lower prevalence of patency [53] as do synthetic conduits. The patency rates are lower when the anastomosis is to small coronary arteries and to arteries supplying areas with considerable scar. Thrombosis, another process that can reduce graft patency, may develop early postoperatively. Endothelial cell loss and exposure of the basement membrane and collagen to blood tend to appear early after inserting the vein graft, predisposing it to early accumulation of platelets, fibrin, and thrombus on its luminal surface.

1.Freedom from angina or heart failure;

*The Current Perspectives on Coronary Artery Bypass Grafting*

3.Preservation of exercise capacity.

gradually begins to decline after about 5 years [34].

reintervention.

least for 3–10 years [38].

**102**

2.Freedom from the need for medication, rehospitalization, and

Most of the patients have a satisfactory quality of life early after CABG, but this

• **Neurobehavioral outcomes**—damaging effects of CPB machine are usually blamed for neurobehavioral disturbances and decline in cognitive function in some patients. These are mild most of the times and might not be apparent unless patients are tested specifically for them. As many as 75% of patients may exhibit these subtle defects when tested 8 days after CABG, but by 3–6 months postoperatively, proportion drops to only about 10–30% [35]. Gross defects most likely result from embolization of arteriosclerotic debris from the ascending aorta or from air and intracardiac thrombus rather than from damaging effects of CPB [36]. Prevalence is about 0.5% in relatively young patients but rises to about 5% in patients older than age 70 and about 8% in those older than 75 [37]. Randomized trials comparing on- and off-pump procedures showed similar prevalence of adverse neurologic outcomes [28].

• **Functional capacity**—maximal exercise capacity of patients is improved by CABG. The degree of exercise capacity depends on preoperative LV function, graft patency, and completeness of revascularization. Maximal exercise capacity generally is improved more by CABG than by medical treatment, at

• **Left ventricular function**—resting regional perfusion defects are improved after CABG in at least 65% of patients [39]. Left ventricular wall segments that are hypokinetic, akinetic, or even dyskinetic at rest preoperatively often have improved systolic function after CABG [40]. This is associated with increased regional myocardial perfusion. Improvement in segmental wall motion 12 months after CABG has been observed even in areas of scarring from previous MI [41]. This finding supports the concept that viable muscle cells, which may be hibernating, are scattered through hypokinetic and, at times, even akinetic and dyskinetic segments and that wall motion in such segments can be improved by CABG [42]. When segmental wall contraction does not occur after CABG, incomplete revascularization is the cause in some patients. LV diastolic function, more specifically LV "relaxation," is also improved by

successful CABG, and improvement may be immediate [43].

• **Exercise**—the decrease in EF with exercise that is a characteristic of ischemic heart disease is absent 2 weeks after operation in most patients. This favorable response to stress can be brought about only by CABG or PCI and does not result from collateral circulation alone, even when extensive [44]. When global and segmental function during exercise is not improved early (3 months) after

operation, one or more bypass grafts are usually occluded or stenosed.

• **Patency of grafts: internal mammary artery**—the highest patency rates for coronary bypass grafts are associated with the use of the left internal mammary (thoracic) artery to bypass the left anterior descending coronary artery. These

*The Current Perspectives on Coronary Artery Bypass Grafting*

**References**

pp. 1087-1113

1998;**19**:23-44

**28**:36

[1] Benjamin EJ, Blaha MJ, Chiuve SE,

*DOI: http://dx.doi.org/10.5772/intechopen.88932*

*Coronary Artery Bypass Grafting: Surgical Anastomosis: Tips and Tricks*

[9] Cooley DA. In memoriam. Tribute to Rene Favaloro, pioneer of coronary bypass. Texas Heart Institute Journal.

[10] Vineberg A, Miller G. Internal mammary coronary anastomosis in the surgical treatment of coronary artery insufficiency. Canadian Medical Association Journal. 1951;**64**:204-210

[11] Effler DB. Chapter 1: History. In: Green GE, Singh RN, Sosa JA, editors. Surgical Revascularization of the Heart: The Internal Thoracic Arteries. Tokyo:

[12] Wijnberg DS, Boeve WJ, Ebels T, van Gelder IC, van den Toren EW, Lie KI, et al. Patency of arm vein grafts used in aorto-coronary bypass surgery. European Journal of Cardio-thoracic

[13] Culliford AT, Colvin SB, Rohrer K,

Baumann G, Spencer FC. The atherosclerotic ascending aorta and transverse arch: A new technique to prevent cerebral injury during bypass: Experience with 13 patients. Annals of

Thoracic Surgery. 1986;**41**:27

[14] Aranki SF, Rizzo RJ, Adams DH, Couper GS, Kinchla NM, Gildea JS, et al. Single clamp technique: An important adjunct to myocardial and cerebral protection in coronary operations. The Annals of Thoracic Surgery. 1994;**58**:296

[15] Puskas JD, Thourani VH, Kilgo P, Cooper W, Vassiliades T, Vega JD, et al. Off-pump coronary artery bypass disproportionately benefits high-risk patients. The Annals of Thoracic Surgery. 2009;**88**:1142-1147

[16] Moller CH, Perko MJ, Lund JT, Andersen LW, Kelbaek H, Madsen JK, et al. Three-year follow-up in a subset of high-risk patients randomly assigned to

Igaku-Shoin; 1991. pp. 1-17

Surgery. 1990;**4**:510

2000;**27**:231-232

[2] Ganz P, Ganz W. Coronary blood flow and myocardial ischemia. In: Braunwald E, Zipes DP, Libby P, editors. Heart Disease. Philadelphia: W.B. Saunders Company; 2001.

[3] Brandt PW, Partridge JB, Wattie WJ. Coronary angiography: A method of presentation of arteriogram report and a scoring system. Clinical Radiology. 1977;

appropriate treatment for stable angina: Safety considerations. Drug Safety.

[4] Asirvatham S, Sebastian C, Thadani U. Choosing the most

[5] Thadani U. Current medical management of chronic stable angina. Journal of Cardiovascular Pharmacology and Therapeutics. 2004;**9**:S11-S29

[6] Food and Drug Administration. Acetylsalicylic acid and the heart. Journal of the American Medical Association. 1993;**270**:2669

[7] Bhatt DL, Fox KA, Hacke W, et al. Clopidogrel and aspirin versus aspirin

atherothrombotic events. The New England Journal of Medicine. 2006;**354**:

[8] Pfeffer MA, Braunwald E, Moye LA, et al. Effect of captopril on mortality and morbidity in patients with left ventricular dysfunction after myocardial infarction. The New England Journal of Medicine. 1992;**527**:

alone for the prevention of

1706-1717

669-677

**105**

et al. Heart disease and stroke Statistics-2017 update: A report from the American Heart Association. Circulation. 2017;**e146**:135
