A quantitative angiographic study of characteristics of internal thoracic artery grafts in coronary artery bypass surgery

In adult patients with atherosclerotic coronary artery disease and in pediatric patients with Kawasaki heart disease, characteristics of internal thoracic artery grafts (ITA grafts) used for coronary artery bypass grafting (CABG) were quantitatively assessed by postoperative angiography. In 142 adult patients with a ITA graft for the left anterior descending artery (LAD), the diameter ratio between ITA graft and recipient LAD at the point close to the anastomotic site (ITA/LAD diameter ratio) was determined by postoperative angiography. This ratio for the adult patients as a whole was 1.04 +/- 0.34. The multivariate analysis (Quantification I) was performed to assess the effects of the following 12 factors on the ITA/LAD diameter ratio: (1) age at the time of operation, (2) sex, (3) time-duration from the operation to angiography, (4) laterality of the ITA used, (5) presence of an undivided major side branch of the ITA graft, (6) presence of blood flow competition between the ITA graft and other grafts, (7) presence of distal stenosis of the recipient LAD, (8) severity of LAD stenosis after the operation, and (9-12) presence of hyperlipidemia, diabetes mellitus, hypertension, or smoking history. The standardized category scores of 25% LAD stenosis, 50% LAD stenosis, and blood flow competition between the ITA and other grafts were -0.815, -0.359, and -0.306, respectively. Insignificant stenosis of the recipient coronary artery was associated with reduction of the ITA/LAD diameter ratio, and this ratio strongly correlated with the severity of LAD stenosis (partial correlation coefficient: 0.627). However, no other factors significantly influenced on the ITA/LAD diameter ratio. In 15 pediatric patients, the length and diameter of 19 ITA grafts and 5 saphenous vein grafts (SVGs) which remained patent in the early (about one month) and late (14 +/- 4 months) postoperative period were determined. Only in the ITA graft, increases in graft length and diameter associated with patient growth were recognized. In the present study, the physiological characteristics of the ITA graft were demonstrated as a viable conduit with flow adaptability and growth potential.     

Comparative study of anticoagulant management after coronary artery bypass surgery--warfarin versus dipyridamole]

A prospective randomized study was performed in 137 coronary artery bypass surgery cases to determine if the administration of antiplatelet drugs would improve the patency of coronary artery bypass grafts. The warfarin group received warfarin and thrombotest was controlled to 20% or so. The dipyridamole group received both 300 mg of dipyridamole and 250 mg of aspirin orally each day. These two groups were compared for study in grafts patency. Results were analyzed by chi-square. In the warfarin group, 66 patients had three ITA-LAD grafts and 115 saphenous vein grafts (including 4 sequential grafts). In the dipyridamole group, 71 patients underwent 38 ITA grafts and 167 saphenous vein grafts (including 56 sequential grafts). Eighty-eight of the 107 grafts (82%) were patent in the warfarin group, and 190 of 205 grafts (95%) were patent in the dipyridamole group (p less than 0.01). Of the two ITA grafts in the warfarin group, no graft was occluded, a patency of 100%. In the dipyridamole group, 35 of 38 ITA grafts (92%) were patent. In the warfarin group, 86 of 105 saphenous vein grafts (82%) were patent. In the dipyridamole group, 155 of 167 saphenous vein grafts (95%) were patent (p less than 0.01). In the study of grafted coronary vessel, the patency of left anterior descending coronary artery, diagonal branch and right coronary artery was not significant between two groups. In the dipyridamole group, the patency of left circumflex coronary artery was 93%, and that of the warfarin group was 50% (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Similarity between internal thoracic artery and gastroepiploic artery graft: pharmacological point of view

The pharmacological responses of internal thoracic artery (ITA), gastroepiploic artery (GEA) and saphenous vein (SV) obtained from patients receiving coronary artery bypass grafting (CABG) were assessed by isometric contraction records. The concentration-response curves for ergonovine and serotonin showed the leftward shift in SV compared with ITA and GEA. The 50% effective dose values of SV for ergonovine and serotonin were significantly less than those of ITA and GEA. The concentration-response curves for phenylephrine were similar among three kinds of grafts. There were no significant differences in the 50% effective dose values for phenylephrine among them. The effect of 0.4% papaverine chloride on the free graft flow was assessed in 15 patients receiving CABG with mean body surface area of 1.62 +/- 0.12 M2. The free flow of ITA graft was 71 +/- 32 ml/min before intraluminal papaverine injection, and that increased to 112 +/- 41 ml/min after injection. The free flow of GEA graft was 82 +/- 39 ml/min before injection, and that also increased to 128 +/- 40 ml/min after injection. The patency rates at the mean 2.2 months after grafting were 98% in ITA, 93% in GEA, and 88% in SV. In conclusion, both GEA graft and ITA graft can be expected as an excellent conduit in myocardial revascularization.     

Structural features of saphenous vein and internal thoracic artery endothelium: correlates with susceptibility and resistance to graft atherosclerosis

Examination of saphenous vein (SV) and internal thoracic artery (ITA) endothelium at the time of coronary bypass surgery has confirmed the known susceptibility of SV to endothelial cell loss during preparation for grafting. In contrast the ITA showed only minimal cell loss. An ultrastructural morphometric analysis of the abluminal surface of the endothelium of both vessels showed significant differences in the numbers and depth of penetration of cytoplasmic processes or folds. Whereas the SV, perfusion-fixed at 110 mmHg, possessed relatively few (15/100 micron) and shallow (less than 1 micron deep) processes the ITA had significantly more (27/100 micron) and deeper (18% greater than 1 micron) processes. The ITA endothelial cells were also smaller and thicker. We suggest that the differences in the numbers and depth of the processes, which are believed to play a role in endothelial attachment, may account for the differing susceptibility of the two vessels to endothelial damage during grafting. This in turn correlates with the known susceptibility of SV grafts and resistance of ITA grafts to atherosclerotic changes.     

Natural Y-grafting using internal thoracic artery branches for off-pump coronary artery bypass

The excellent long-term patency rates achieved utilizing the internal thoracic arteries (ITAs) have stimulated a variety of approaches to expand the use of these conduits in coronary revascularization. The ITA divides at the level of the fifth or sixth intercostal space into the superior epigastric and musculophrenic branches. If these terminal branches of the ITA are large and long enough for grafting, they can be used to construct a "Y" anastomosis to the coronary arteries. We experienced 2 patients who underwent multivessel off-pump coronary artery bypass (OPCAB) using these ITA branches. In both patients the bilateral ITAs and the right gastroepiploic artery were taken down using the skeletonization technique as in situ grafts. One patient had 5 grafts including the right ITA terminal branches which were used for the left anterior descending branch (LAD) and diagonal branch. Another patient had 6 grafts including the left ITA terminal branches which were used for the posterolateral branch (PL)1 and PL2. Postoperative angiography revealed widely patent grafts in both patients. We believe that one of the advantages of applying the off-pump technique when the ITA branches are used is that it might be easier to arrange the angle of constructing a natural "Y" configuration compared with conventional coronary artery bypass grafting (CABG). In conclusion, the terminal branches of the ITA, if of suitable size, should be considered for "Y" grafts to diseased coronary arteries when performing complete arterial revascularization with only in situ grafts.     

Long-term results of bilateral internal thoracic artery grafting

Background. Little is known about the long-term results of the uniform group of patients who had bilateral internal thoracic artery (ITA) grafting with the method of left ITA-to-left anterior descending coronary artery and right ITA-to-circumflex artery.

Methods. Late follow-up study was performed in the first consecutive 203 patients (mean age, 62.6 ± 9.1 years) who underwent isolated coronary artery bypass grafting with the left ITA anastomosed to the left anterior descending coronary artery and the right ITA to major branches of the circumflex artery. The patients were grouped according to the patency of ITA grafts demonstrated by early postoperative angiography (Both patent (BP) group, 168 patients: both ITAs showed complete patency; Not patent (NP) group, 23 patients: at least one ITA was dysfunctional).

Results. Actuarial 7-year survival in all patients was 89.3% ± 3.1%. The cumulative probability of event-free survival for cardiac death, myocardial infarction, intervention, and angina at 7 years was 96.6% ± 1.8%, 98.0% ± 1.5%, 86.7% ± 3.2%, and 90.7% ± 2.9%, respectively. NP group had more myocardial infarction and angina than the BP group, but was not statistically significant. Because of failed grafts at the early angiography, intervention was performed more frequently in NP group (p < 0.01).

Conclusions. Our results of actuarial 7-year survival and the cumulative probability of event-free survival were at least comparable to the results of other similar studies using bilateral ITA. The freedom from angina appeared to be better than in the previous study. Overall our study supports the continued use of this method of ITA grafting.     

Coronary revascularization with bilateral internal thoracic artery grafts]

Thirty-two patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts. Each patient received 2.7 grafts in average including double ITA grafts. Seventeen patients had the right ITAs as free grafts. The other sixteen were treated with 13 autologous veins and 9 right gastroepiploic arteries in addition. Fifty-five grafts out of 56 (98.2%) were proved to be patent at the time of hospital discharge. The postoperative morbidity included three reoperations for bleeding and one perioperative inferior myocardial infarction. One patient died of colon perforation after surgery and another died of cerebral infarction late after surgery. These results exhibited that coronary artery bypass grafting with bilateral ITA grafts had relatively low risks and could contribute to complete revascularization in patients with diseased coronary arteries.     

Angiographic 20-year follow-up of 61 consecutive patients with internal thoracic artery grafts.

OBJECTIVE: To assess the behavior of internal thoracic artery (ITA) grafts versus venous grafts in repeated angiograms up to 20 years. SUMMARY BACKGROUND DATA: Use of ITA grafts to bypass left anterior descending artery stenosis has been shown to be associated with improved survival in patients undergoing coronary artery bypass grafting. METHODS: Sixty-one consecutive patients who received one or two ITA grafts and who underwent surgery from Oct. 5, 1971, to Dec. 18, 1973, in Helsinki University Central Hospital, Finland, were included in this prospective follow-up series. Fifty-six of the patients (92%) also received at least one venous graft. The number of distal anastomoses was 157, of which 47.7% (75) were performed with ITA grafts. The median age of the patients was 47.7 years (range 30.0 to 63.1), and 85% (52) were men. RESULTS: After 20 years of follow-up, 18/20 (90%) of the survivors underwent angiography; the patency rate was 88.9% for ITA grafts and 47.8% for venous grafts. Cumulative graft patency at 20 years, using all the information obtained from repeated angiographic examinations and autopsies, was also calculated to eliminate selection bias. The cumulative 20-year patency rate was 81% for ITA-left anterior descending artery anastomoses, 53.8% for venous graft-right coronary artery anastomoses, and 48.5% for venous graft-left circumflex artery anastomoses. In paired comparisons between anastomoses, the patency time of the ITA-left anterior descending artery anastomoses was on average 2.8 years longer than the venous graft-left circumflex artery patency time and 2.6 years longer than the venous graft-right coronary artery. CONCLUSIONS: Internal thoracic artery grafts, especially in left anterior descending artery anastomoses, should be considered as a primary solution in coronary artery bypass grafting surgery in patients with >10 years of life expectancy; if venous grafting is preferred, further evidence is needed.     

Redo off-pump coronary artery bypass grafting for high risk hemodialysis patients

BACKGROUND: The number of reoperative (redo) coronary artery bypass grafting (CABG) for patients with long-term hemodialysis has been increasing. Off-pump CABG (OPCAB) may decrease risks associated with redo CABG. METHODS: Two patients on chronic hemodialysis with calcification of the ascending aorta underwent redo double coronary OPCAB for the left anterior descending artery (LAD) and the posterior descending artery (PDA) via median sternotomy. The LAD was bypassed with the left internal thoracic artery (LITA). The PDA was exposed with minimum dissection and bypassed with a composite graft of the right internal thoracic artery (RITA) and the saphenous vein (SV). RESULTS: Both patients made a quick recovery with no complications and one had postoperative angiography that showed the patent grafts. Both patients were free from angina pectoris at follow-up of 6 months and 3 months, respectively. CONCLUSION: Redo OPCAB of the LAD and PDA can be performed with minimal dissection via median sternotomy using the LITA and a composite graft of the RITA and SV.     

Revascularization with bilateral internal thoracic artery grafts in patients with left main coronary stenosis.

Left main occlusive disease (LMD) is a potentially fatal lesion which is optimally treated with surgical revascularization. Although the internal thoracic artery (ITA) is recognized as having superior long term patency, there has been concern regarding possible flow limitation. Because of this concern, there may be reluctance to use only this conduit in patients with LMD in whom high graft flows are desirable. From 1985 to 1990, 45 patients (38 males, 7 females) with LMD ranging in age from 37 to 75 years (mean 55.9 +/- 8.7) underwent revascularization using bilateral ITA grafts placed to the left anterior descending and circumflex arteries. The right ITA was used as a free graft in 19 of 45 (42%) patients and the left ITA was used as a free graft in 3 of 35 (7%). No saphenous vein grafts were placed to the left coronary system in any patient. Over half of these patients (24 patients, 53%) also had occlusive disease in the right coronary artery. A saphenous vein graft was placed to the right coronary artery in 22 of 45 (49%) patients. Ventricular function in this patient subset was good (mean LV score 7.1 +/- 2.1). Intra-operative ITA graft flows were 49.7 +/- 29.1 ml/min for grafts to the left anterior descending and 45.5 +/- 31.7 ml/min for circumflex grafts. There were no perioperative deaths. Morbidity included myocardial infarction, stroke and reoperation for bleeding in 1 patient each (2.2%). Low cardiac output occurred in 2 patients (4.4%). No patient had a mediastinal wound infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extended use of bilateral internal thoracic arteries for coronary artery bypass grafting in the elderly

Objective: Internal thoracic artery (ITA) grafts provide better early and long-term patency than saphenous vein (SV) grafts. Furthermore, bilateral ITA grafting has recently demonstrated better long-term results than unilateral ITA grafting. However, its use in the elderly is controversial. Methods: From March 1991 through November 2001, 307 consecutive patients aged 65 years or over undergoing isolated coronary artery bypass grafting (CABG) were reviewed, and the influence of bilateral ITA grafting on the early and long-term results was evaluated. All ITA grafts were harvested as a pedicle, and almost all of which were used as in-situ grafts. Results: Operative mortality in 138 patients undergoing bilateral ITA grafting was 1.4%, and in 108 patients undergoing unilateral ITA grafting, the rate was 0.9%. Predischarge angiography conducted in 97% of the subjects showed that the patency rate of all the ITA grafts (98.9%) was superior (p<0.0001) to that of all the SV grafts (93.6%). In comparisons of survival and freedom from cardiac events at 10 years after CABG, the bilateral use of ITA grafts was proved to be more beneficial than the unilateral use (p<0.05). Conclusions: It was demonstrated that bilateral ITA grafting could be performed with acceptable mortality and morbidity. Moreover, it offers better long-term survival and freedom from cardiac events than either unilateral ITA grafting or no ITA grafting. Bilateral ITA grafting thus can serve as a favorable procedure even in elderly patients.     

The impact of chronic renal failure on atherosclerosis of the internal thoracic arteries

BACKGROUND: Little is known about the impact of renal failure on atherosclerotic changes in the internal thoracic artery (ITA). METHODS: A total of 20 consecutive patients on chronic dialysis who underwent coronary artery bypass grafting (CABG) during April 1998 through September 1999 were investigated. The 20 control patients were selected from the same interval to rigorously match risk factors. Atherosclerosis of the ITA collected from each patient was analyzed using the subjective evaluation proposed by Kay and colleagues. RESULTS: There were no cases of greater than 25% atherosclerotic luminal narrowing among a total of 35 ITA specimens from dialysis patients. The degree of atherosclerosis was not significantly different from that of the specimens from matched patients (p = 0.18). No calcification was found in ITA grafts either microscopically or macroscopically. The number of elastic lamellae, an index of the elasticity of the ITA graft, was not significantly different from those obtained from the matched patients. Analysis of preoperative coronary angiography revealed that coronary calcification was significantly more frequent in dialysis patients (15 patients, 75%) than in matched patients (p < 0.05). By analysis of postoperative angiography in dialysis patients, no evidence of atherosclerotic changes was found in 28 opacified ITAs. In addition, despite the presence of calcification in the native coronary, no calcification was evident along the entire length of the ITAs. CONCLUSIONS: This study revealed the minimal impact of chronic renal failure on atherosclerotic changes in the ITA. The results of this study support the continued use of ITA grafting in dialysis patients.     

Minimally invasive direct coronary artery bypass grafting for third-time coronary artery revascularization.

We performed a minimally invasive direct coronary artery bypass (MIDCAB) on two patients for third-time revascularization. The first patient was a 66-year-old woman who had patent bilateral internal thoracic artery (ITA) grafts and an occluded radial artery (RA) graft anastomosed to the posterolateral (PL) branch. She underwent her third revascularization for left circumflex coronary artery reconstruction with the MIDCAB technique using the right gastroepiploic artery. The second patient was a 65-year-old man who had occluded saphenous vein grafts (SVGs) on the anterior aspect of the heart, a stenotic left ITA graft to the left anterior descending artery, and a stenotic SVG to the PL branch. He underwent his third revascularization by MIDCAB using a bilateral RA-Y graft. Postoperative angiography of the two cases showed that the new grafts were widely patent.     

Coronary artery bypass grafting in patients with systemic lupus erythematosus.

OBJECTIVE: Few reports exist on the results of coronary artery bypass grafting (CABG) in patients with systemic lupus erythematosus (SLE). METHODS: We retrospectively reviewed eight CABG in seven SLE patients. In early and late postoperative angiography, all grafts were evaluated for occlusion, development of string sign, or presence of significant stenosis. The early and late results were compared. The pathological studies were performed on the segments of the internal thoracic artery (ITA) and saphenous vein collected from each patient. Atherosclerosis of the ITA was analyzed using the subjective evaluation proposed by Kay et al. (Kay HR, Korns ME, Flemma RJ, Tector AJ, Lepley D. Atherosclerosis of the internal mammary artery. Ann Thorac Surg 21;1976:504-507) scale 0-4 (0 = normal, 1 = minimal disease, 2 = less than 25% luminal narrowing, 3 = 25-50% narrowing, and 4 = greater than 50% narrowing). RESULTS: The patients consisted of three men and four women with a mean age of 59.8 years. Co-morbid diseases were frequent and there were three patients (37.5%) with renal failure (two dialysis patients, one with renal dysfunction) and two patients with severe atherosclerosis of the aorta. The ITA was used in four patients. Saphenous vein graft was used in seven patients. Concomitant procedures included aortic valve replacement and mitral annuloplasty, mitral valvuloplasty and tricuspid annuloplasty, mitral valve replacement and tricuspid annuloplasty (TAP). There was one hospital death (12.5%). Early patency rates were 87.5% (21/24). No other atherosclerotic changes or stenosis suggesting vasculitis were noted. In pathological studies, there was no significant atherosclerosis in the six ITA specimens from four patients, although three patients had degree two atherosclerosis. No vasculitis was found in ITA or saphenous vein grafts. During the mean follow-up period of 35.3 months (range, 5-91 months), there was one non-cardiac late death. Late restudy (in three patients, 12, 57 and 64 months later respectively) revealed no deterioration in either ITA or vein grafts. Overall prognosis after the operation in SLE patients appears to be good. No other cardiac events were observed, and patients demonstrated marked clinical improvement. CONCLUSIONS: CABG in SLE patients can be performed with acceptable morbidity and mortality. Our data so far reveals no evidence to preclude the use of ITA and vein grafts in SLE patients.     

Clinical results of free (aorta-coronary) internal thoracic artery grafting

In the two year period from 1989 to 1990, 22 patients (18 men, 4 women; age range from 40 to 59 years) underwent coronary artery bypass grafting (CABG) using in situ and free internal thoracic arteries (ITAs). 23 of total 38 ITA grafts were free grafts in the aorta-coronary position, mainly to provide sufficient graft length. All of 34 ITA grafts were patent in 20 patients with coronary arteriography about one month after operation. There were no early and late death, and all patients were free from angina after a 9.4 month mean follow-up. Perioperative complications included reoperation for the bleeding in one case and the elevation of left diaphragm in one case, but there was no other major complication such as perioperative myocardial infarction, cerebral infarction or mediastinitis. These results indicated that the free ITA could be applied as well as the in situ ITA in multiple CABG of the Japanese with good patency rate and low operative risk.     

Redo coronary artery bypass grafting using the patent left internal thoracic artery graft as an in flow with composite internal thoracic artery Y grafting; report of a case

In redo coronary artery bypass grafting (CABG), graft selection and revascularization methods are major problems. We experienced a redo-CABG with occluded previous vein grafts. These grafts were to the circumflex artery and right coronary artery. We conducted operation using cardiopulmonary bypass. We at this operation, chose right internal thoracic artery (RITA) as a conduit and anastomosed it to the side of functioning left internal thoracic artery (LITA) graft, and then diogonal branch, posterolateral branch, and atrioventricular branch were revascularized with the RITA. Post operative course was uneventful. Internal thoracic artery (ITA) is superior to vein graft and other arterial graft as to long term patency. We believe composite Y graft with the use of bilateral ITA can be one of the revascularization strategy in redo CABG.     

Results of internal thoracic artery grafting over 15 years: single versus double grafts

One hundred consecutive patients who had coronary artery bypass grafting using both internal thoracic arteries (ITAs) and saphenous veins, operated on during a 3-year period between 1972 and 1975, have been compared retrospectively with a series of 100 patients operated on during the same period who had one ITA graft along with saphenous vein grafts. The two groups were similar with respect to age, sex, risk factors for coronary artery disease, angina class, extent of coronary artery disease, left ventricular function, number of coronary bypass grafts performed, and completeness of revascularization. Single ITA operative mortality was 2% and double ITA, 9% (p = NS). The mean follow-up of hospital survivors was 14.4 +/- 2.7 years; all but 7 patients had follow-up for at least 10 years. At 13 years, the actuarial patency of the right ITA was 85% and the left ITA, 82%. These data strongly suggest a survival benefit for patients with double ITA grafts among hospital survivors (74% versus 59%; p = 0.05). Patients receiving two ITA grafts had a significant freedom from subsequent myocardial infarction (75% versus 59%, p less than 0.025), recurrent angina pectoris (36% versus 27%, p less than 0.025), and subsequent total ischemic events (32% versus 18%, p less than 0.01). These data also suggest improved freedom from coronary artery interventional therapy (percutaneous transluminal coronary angioplasty and reoperation) when two ITA grafts were used. These results support the use of bilateral internal thoracic artery grafting in selected patients.     

Purely internal thoracic artery grafts: outcomes

BACKGROUND: Most of our patients with coronary artery disease have undergone bypass exclusively with purely internal thoracic artery grafts (PITA). Our goal has been to lengthen the time a patient benefits from coronary bypass operations. The present report describes an 8.5-year study of outcomes including mortality and the need for reintervention in patients who have undergone bypass with PITA. METHODS: We studied 897 patients who underwent PITA with a total of 3,784 internal thoracic artery (ITA) grafts (4.2 grafts per patient). Connecting ITA to ITA along with sequential anastomosis made the procedure possible. RESULTS: Early mortality for the group was 2.3%. Freedom from death was 86% and freedom from reintervention was 94% at 5 years after the operation. CONCLUSIONS: The acceptable early and late mortality and the 94% freedom from reintervention as long as 8.5 years after operation in this group of patients inspire us to continue choosing PITA for patients with three-vessel coronary artery disease.     

Experimental study on coronary bypass grafts--functional and pathologic comparison of late changes in various coronary grafts]

The internal thoracic artery (ITA) has excellent long-term patency when used as a conduit for coronary artery bypass (CAB), but there are still some problems, such as flow capacity and limited graft length of the ITA. This study was performed to evaluate the functional and pathologic late changes in left ITA grafts (LITAG), vein grafts (VG), ITA-vein (ITA-VG) and ITA-ITA composite grafts (ITA-ITAG) in a canine model of coronary artery bypass. Twenty-nine adult mongrel dogs underwent bypass of the left circumflex coronary artery (CX) with one of the above grafts. More than five months postoperatively (mean follow up period 245 +/- 78 days), changes in graft flow (CX flow in control group), mean aortic pressure (AoP), left ventricular end diastolic pressure (LVEDP), diastolic pressure time index/tension time index (DPTI/TTI), left atrial pressure (LAP) and right atrial pressure (RAP) with atrial pacing were compared with control group, and postmortem specimens were examined microscopically. With atrial pacing, AoP and RAP did not change in any group. Increases in graft flow, LVEDP and LAP with decrease in DPTI/TTI were observed in ITAG and ITA-ITAG groups, but these changes were similar to control group. On the other hand, increases in LVEDP and LAP with decreases in graft flow and DPTI/TTI were observed in VG and ITA-VG groups, and these changes were different from control group. No atherosclerotic change without anastomotic site was observed in any ITA which was used in ITAG, ITA-ITAG and ITA-VG groups, while intimal thickening and irregular dilatation were observed in al veins which were used in VG and ITA-VG groups. In conclusion, this study shows that ITA is a excellent conduit for CAB because of sufficient flow capacity and no atherosclerosis without anastomotic site in a long-term period. And to elongate ITA as a CAB graft, ITA-ITAG could be more appropriate than ITA-VG.     

Coronary-coronary bypass using the internal thoracic artery: a sparing procedure of the arterial conduit

BACKGROUND: The internal thoracic artery (ITA) is well known to be the best conduit for coronary artery bypass grafting. However, the bilateral use of ITAs remains limited because in situ right ITAs (RITAs) do not possess an adequate length to be directed to the posterolateral myocardium. We thus considered using free ITAs for conduits between the two segments of the same coronary artery. METHODS: From March 1997 to May 1999, 17 patients underwent coronary-coronary bypass grafting (C-CBG) using free ITAs. Early operative results were analyzed. C-CBG was indicated when the right ITA had an inadequate length or when a distal part of the ITA was left unused. RESULTS: No patient died after C-CBG and none have experienced angina since C-CBG (mean follow-up period 27.3 +/- 19.8 months). Postoperative angiography was performed in all subjects at discharge. Only one coronary-coronary bypass graft was occluded, the other grafts were patent, and there were no stenotic changes. Bilateral ITAs were used in 75% of the patients undergoing CABG during the period of this study. CONCLUSIONS: C-CBG can expand the use of bilateral ITAs and can provide an alternative method for revascularization of the posterolateral myocardium.