A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery.

We used quantitative angiography to determine the postoperative diameter of the internal thoracic artery graft at the point close to the anastomosed site in 147 patients who received the graft for the left anterior descending coronary artery. We performed generalized multiple linear regression analysis (Type I quantification method) to assess the effects of the following factors on the internal thoracic artery graft diameter: age, gender, time of angiography, laterality of the internal thoracic artery used, presence of an undivided major side branch of the internal thoracic artery, presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft, presence of distal stenosis of the recipient left anterior descending coronary artery, severity of postoperative left anterior descending coronary artery stenosis, and presence of coronary risk factors. The standardized category scores for 25% left anterior descending coronary artery stenosis, 50% left anterior descending coronary artery stenosis, and presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft were -1.418, -0.767 and -0.622, respectively. Thus, the internal thoracic artery diameter was smaller in patients with well-preserved flow of the recipient coronary artery. The internal thoracic artery diameter had a particularly strong correlation with the degree of left anterior descending coronary artery stenosis (partial correlation coefficient: 0.670). The other factors seemed to have little or no correlation with the postoperative internal thoracic artery diameter. With the criterion that the internal thoracic artery diameter below 1.0 mm represents the "string sign" of internal thoracic artery graft, this phenomenon was observed in nine patients (6.1%). In all of these patients, left anterior descending coronary artery flow was well-preserved, and no ischemia was disclosed in the left anterior descending coronary artery-perfused area. These results indicate that internal thoracic artery grafts have flow adaptability responding to the flow demand of the recipient coronary artery and that the string sign of internal thoracic artery grafts is mainly an outcome of its physiologic characteristics.     

Coronary bypass surgery using the internal thoracic artery after reconstruction of occluded subclavian artery.

We present two cases with an occluded left subclavian artery requiring coronary artery bypass grafting. A preoperative angiogram confirmed that the subclavian artery, including the internal thoracic artery distal from the occlusion, was thoroughly intact, in both cases. Immediately after reconstructing the subclavian artery using an aortoaxillary bypass with an 8 mm ring-reinforced polytetrafluoroethylene graft, each patient underwent double coronary artery bypass grafting using the affected left internal thoracic artery with either the right internal thoracic artery or a saphenous vein in the same anesthetic setting. Symptomatic relief was excellent. In both cases, a postoperative angiographic study showed good function of the left internal thoracic artery graft supplying blood to the coronary artery through the aortoaxillary bypass graft.     

Spontaneous recanalization of functionally occluded bilateral internal thoracic artery T graft

Functional occlusion of the left internal thoracic artery T graft is reported. The patient underwent triple coronary artery bypass grafting with bilateral internal thoracic artery, anastomosing in situ to the left internal thoracic artery to the left anterior descending artery, free right internal thoracic artery to the obtuse marginal and posterolateral branch of the left circumflex artery. Early angiography showed occlusion of the in situ left internal thoracic artery to the moderately stenosed left anterior descending artery and patent side arm to circumflex. However, mid-term angiography revealed restoration of the left internal thoracic artery flow. A negative exercise stress test was noted throughout the postoperative period. Flow competition with a native coronary artery may be responsible for functional occlusion of the left internal thoracic artery.     

Lateral femoral circumflex artery for coronary artery bypass surgery in a patient receiving hemodialysis: report of a case

A 59-year-old man receiving hemodialysis had a 2-vessel coronary disease. We performed double coronary artery bypass grafting with the left internal thoracic artery to the left anterior descending artery, and the composite graft of right internal thoracic artery and lateral femoral circumflex artery to the right coronary artery. Postoperative coronary angiogram showed that the LFCA bypass graft was widely patent and supplied sufficient blood to the anastomosed vessel. There was no stenosis at the anastomotic site. He had no postoperative complication. Long-term follow-up and more cases is necessary to establish the usefulness of LFCA as an arterial free graft for coronary revascularization in patients receiving hemodialysis.     

Right internal thoracic artery remodeling 18 years after circumflex system grafting

A 64-year-old man with left main coronary artery disease underwent myocardial revascularization. The left internal thoracic artery (LITA) was sutured to the left anterior descending artery, and the right internal thoracic artery (RITA) was sutured to the obtuse marginal artery. Eighteen years later, angina reoccurred. Catheterization revealed that both the coronary and the left subclavian arteries were occluded and that a patent RITA graft was maintaining the cardiac blood supply. The RITA graft evaluation revealed increased lumen diameters, suggestive of remodeling. The LITA was subsequently disconnected and sutured to the aorta as a free graft in order to restore appropriate myocardial blood flow. This case emphasizes the benefits of using a live graft for left coronary system grafting, which include long-term patency and flow-dependent remodeling.     

Effects of atrial fibrillation on coronary artery bypass graft flow.

OBJECTIVES: No detailed studies exist of coronary artery bypass graft flow during atrial fibrillation. We examined the effects on bypass graft flow of atrial fibrillation following coronary artery bypass grafting. METHODS: Immediately after surgical revisualization, atrial fibrillation was induced in 18 patients by high frequency atrial pacing. Hemodynamic variables were measured in sinus rhythm and atrial fibrillation. The graft flow in pedicled left internal thoracic artery grafts and in saphenous vein grafts was also measured using transit-time flowmetry. RESULTS: Left internal thoracic artery graft flow had a greater diastolic component than saphenous vein graft flow, as shown by the percent diastolic time-flow integral (86 +/- 10% in the left thoracic artery and 62 +/- 12% in the saphenous vein, P < 0.0001). The induced atrial fibrillation caused significant deterioration in hemodynamics: heart rate and central venous pressure increased, and mean arterial pressure and cardiac index decreased (all P < 0.0025). In left internal thoracic artery grafts (n = 18) and also in saphenous vein grafts (n = 20), graft flow decreased significantly with atrial fibrillation (44.3 +/- 26.2 to 26.2 +/- 20.7 ml/min in the left internal thoracic artery, P = 0.0003; 39.7 +/- 15.6 to 33.3 +/- 14.3 ml/min in the saphenous vein, P = 0.001). The reduction in graft flow due to atrial fibrillation was much larger in left internal thoracic artery grafts than in saphenous vein grafts (P = 0.0008). CONCLUSIONS: Direct measurement of coronary artery bypass graft flow shows that atrial fibrillation after surgery significantly reduces graft flow. The effect is much larger in left internal thoracic artery grafts with their strong diastolic component than in saphenous vein grafts.     

Aortic valve replacement in a patient with a patent internal thoracic artery graft

Myocardial protection in patients requiring a second open-heart surgical procedure after coronary artery bypass grafting, especially when there is a patent left internal thoracic artery graft to the left anterior descending coronary artery, remains controversial. We present the case of a patient in whom aortic valve replacement was undertaken 18 months after coronary artery revascularization. Unusual features included beating-heart aortic valve replacement with continuous retrograde coronary sinus perfusion and avoidance of dissection of the patent grafts, including the left internal thoracic artery and a saphenous vein graft.     

Segmentation of the left internal thoracic artery: a new technique for maximal arterial grafting

The left internal thoracic artery lpa r;LITA) is the preferred graft with the best patency rate in coronary artery bypass grafting (CABG). To maximize its use, we developed a technique of grafting 2 distant coronary arteries with the LITA, using its distal portion segmented to construct a Y graft with either the in situ LITA or right internal thoracic artery (RITA). We applied this technique in 51 patients. The distal segment of the LITA was used to create a Y graft in 4 different configurations according to coronary pathology. Offpump grafting was performed in 11% of cases. The use of a distal segment of the LITA was thus extended not only to the left anterior descending artery and branches but also to the circumflex and right coronary artery territories.     

Morphological differences of the internal thoracic artery in patients with and without coronary artery disease--evaluation by duplex-scanning.

OBJECTIVE: The internal thoracic artery is an established arterial graft for myocardial revascularisation, especially of the left anterior descending artery because of a higher patency rate compared to venous grafts. It has never been investigated, whether there are morphological differences in this vessel between patients with or without coronary artery disease or if they are comparable to morphological changes in the common carotid artery. METHODS: We investigated the internal thoracic artery and the common carotid artery of 24 patients (12 with coronary artery disease, 12 without coronary artery disease) with an ultrasonic system on both sides. The intima-media thickness and the diameter of both vessels were estimated. RESULTS: The intima-media-thickness of the internal thoracic artery was comparable in all patients, independent of the presence of a coronary artery disease (0.51+/-0.11 mm with coronary artery disease, 0.50+/-0.17 mm without coronary artery disease, P>0.05). Compared with this the intima-media-thickness of the common carotid artery was thicker in patients with coronary artery disease (0.84+/-0.13 mm with coronary artery disease, 0.73+/-0.07 mm without coronary artery disease, P< or or =0.014). There was no correlation between the thickness of the internal thoracic artery and the common carotid artery (r=0.018, P>0.05). CONCLUSIONS: It could be demonstrated for the first with non-invasive ultrasound, that the intima-media-complex of the internal thoracic artery is protected of the influence of arteriosclerosis. There are no morphological differences like the intima-media-thickness of the common carotid artery. The proven protective mechanism underlines the widespread use of the internal thoracic artery as a coronary artery bypass graft.     

Mid-term angiographic results of radial artery (RA) graft in CABG: Does the proximal site of anastomosis affect graft patency?

Background Use of arterial conduits in coronary artery bypass grafting (CABG) is based on the documented excellent patency rates of left internal thoracic (mammary) artery (LITA). Alternative arterial conduits such as radial artery and gastroepiploic artery also showed superior long-term patency rates compared to vein grafts. Free arterial grafts are being used increasingly to replace the long saphenous vein as a conduit. This study was undertaken to compare two methods of radial artery grafting as a free graft and a composite graft. Methods Between January 1997 and October 2003 a total of 441 patients were operated for coronary artery bypass grafting using radial artery (RA) as one of the conduits. Among these patients, 125 patients received radial artery as a composite graft; In 68 patients RA was used with left internal thoracic artery as a composite y graft (n=68), and in 57 patients it was used with right internal thoracic artery (RITA) as an in situ composite pedicle graft (n=57). In the remaining 316 patients the radial artery was used as a free graft. Angiographic evaluation of radial artery graft was carried out in 63 patients who consented. Angiograms were carried out after an interval of 6–72 months (mean of 28.15±21.17 months). Of these 63 patients who underwent reangiography, the different surgical strategies used were RITA+RA composite in situ graft (n=34), LITA+RA composite y graft (n=17) and aorto coronary (free) RA graft (n=12). Results There were 3 hospital deaths in the series 441 patients. Among the 63 patients who underwent check angiography 60 patients were in NYHA C1 I and 3 patients were in C1 II. None of the patients had perioperative myocardial infarction. Angiographically overall radial artery graft patency rate was 94.1% (59 patients). In patients with RITA and RA in situ grafts patency rate was 94.1%, LITA+RA composite y graft patency was 94.1% and aorto coronary (free) radial artery grafts patency was 91.6%. Conclusion In 63 selected asymptomatic patients studied, we found that radial artery graft when used as an aortocoronary (free) graft or as a composite y graft with left internal thoracic artery or in situ pedicle graft with right internal thoracic artery the patency rates were comparable in all three groups.     

Complete arterial coronary revascularisation using radial artery conduit for double thoracic artery inlet flow: arterial sling operation.

BACKGROUND: Coronary artery bypass graft surgery with arterial revascularisation of all diseased coronary vessels is considered highly efficient because arterial grafts have an excellent long-term patency compared with venous grafts. However, problems to reach the infero-lateral wall with the in situ internal thoracic arteries usually require alternative techniques. We present the first results of a new surgical principle using a free radial artery segment to complete the arterial coronary revascularisation and concomitantly connect the internal thoracic arteries. METHODS: In patients referred for coronary bypass surgery and three-vessel disease an end-to-end anastomosis of the right internal thoracic artery and the radial artery segment preceded cardiopulmonary bypass, during which side-to-side anastomoses of the radial artery segment were used to revascularise stenotic branches of the right coronary and circumflex arteries. The left internal thoracic artery was used for revascularisation of stenotic branches of the left anterior descending artery, and finally an end-to-side anastomosis of the radial artery segment to the left internal thoracic artery was performed. Coronary artery blood flow was measured in 41 patients with Doppler flow probe. RESULTS: One hundred and ninety-two coronary anastomoses (an average of 4.2 per patient) were performed in 46 patients. We measured a mean total blood flow in the arterial sling graft of 104ml/min (range 35-221ml/min), compared with 69 and 68ml/min of the single inlet right and left internal thoracic arteries, respectively (P<0.01). Flow capacities of 104 and 120ml/min of the right and left internal thoracic arteries were measured during clamp of both the aorta and the contralateral internal thoracic artery. The mean crossclamp duration was 77min (range 51-113min). Postoperative angiography demonstrated patent graft anastomoses to all coronary arteries. There were no perioperative deaths or myocardial infarctions. One patient had a minor postoperative stroke. DISCUSSION: Complete arterial revascularisation can be achieved by the arterial sling operation with an acceptable crossclamp time and a high early rate of graft patency. The double arterial inlet provides a 50% higher blood flow to the beating heart and two-fold increase in the flow reserve compared with a single inlet. Although further research including long-term follow-up of this new principle is required, the present findings seem promising and suggest that the arterial sling operation has a potential role for complete arterial coronary revascularisation.     

Reoperative coronary artery bypass via left thoracotomy.

The patient was a 49-year-old woman. When she was 39 years old, she underwent coronary artery bypass grafting (left internal thoracic artery to left anterior descending artery, saphenous vein graft to first diagonal branch). At the age 48, she had effort angina. On coronary angiography, triple-vessel disease was found, and she was treated conservatively. Progression of the disease was confirmed with detection of the left circumflex artery associated with jeopardized collateral to the right coronary artery showing total occlusion. The patient underwent reoperation. Since the left internal thoracic artery was patent despite occlusion of the saphenous vein graft, the approach of left thoracotomy was employed. Under cardiopulmonary bypass with ventricular fibrillation and left vent through left atrial appendage, the right radial artery was anastomosed to the left circumflex artery from the descending thoracic aorta, and the right gastroepiploic artery was anastomosed to the right coronary artery (4AV branch). Patency of the bypass was confirmed postoperatively. We consider this operative technique was especially useful for reoperation in cases of a patent internal thoracic artery in which left thoracotomy can be conducted safely.     

Free right internal thoracic artery in a "horseshoe" configuration: a new technical approach for "in situ" conduit lengthening

Severe chronic obstructive pulmonary disease with large lung volumes may prevent both the "in situ" internal thoracic arteries to reach coronary anastomoses sites. We present a method to revascularize the left antero-lateral myocardial wall using the right internal thoracic artery as a "free graft" anastomosed side to end to the "in situ" left internal thoracic artery, in a "horseshoe" fashion. The two ends of the "free graft" were anastomosed to the left anterior descending coronary artery and the second obtuse marginal branch, respectively. This method was successfully used in a 74-year-old patient with severe chronic obstructive pulmonary disease.     

Hydrodissection technique of harvesting left internal thoracic artery

Use of internal thoracic arteries in coronary artery bypass surgery has become universal. Skeletonized internal thoracic artery is useful in coronary artery surgery for sequential anastomosis as it also provides a long length of graft. Skeletonizing the conduit is technically more difficult than harvesting it as a pedicle graft. We describe a technique of harvesting the internal thoracic artery in which 10 to 20 mL of normal saline is injected into the fascial plane of the left side of chest wall along the course of artery to develop a plane of dissection.     

Composite arterial Y graft has less coronary flow reserve than independent grafts

BACKGROUND: It is not known whether a composite Y graft of the left internal thoracic artery can provide sufficient blood flow to the whole left coronary system. The aim of this study was to compare regional myocardial blood flow (MBF) and coronary flow reserve after coronary artery bypass grafting using arterial composite Y graft or independent arterial grafts. METHODS: Positron emission tomography was performed at rest and after dipyridamole infusion using oxygen-15-labeled water 2 weeks after coronary artery bypass grafting. Regional MBF was calculated in seven segments of the left ventricle. Coronary flow reserve was defined as the ratio of MBF after dipyridamole infusion to MBF at rest. In the Y graft group (n = 22), a free arterial graft to obtuse marginal arteries was anastomosed to the proximal side of in situ left internal thoracic artery, which was anastomosed to the left anterior descending artery. In the independent graft group (n = 13), left anterior descending and obtuse marginal arteries were independently revascularized using in situ left internal thoracic artery and a free arterial graft. RESULTS: There was no difference between the groups in MBF at rest. Coronary flow reserve in the Y graft group was lower than that in the independent group in the anterobasal (1.43 +/- 0.07 versus 1.90 +/- 0.13, p = 0.038), apical (1.24 +/- 0.06 versus 1.64 +/- 0.12, p = 0.003), septal (1.34 +/- 0.05 versus 1.75 +/- 0.13, p = 0.023), and lateral regions (1.19 +/- 0.04 versus 1.66 +/- 0.09, p = 0.001). CONCLUSIONS: Although arterial composite Y graft improved MBF at rest, it was not as effective as independent grafts for improving coronary flow reserve soon after coronary artery bypass grafting.     

Bilateral internal thoracic artery T grafting for coronary artery revascularization

OBJECTIVES: We studied the early outcome of bilateral internal thoracic artery T grafting. METHODS: Coronary artery bypass grafting was studied retrospectively using bilateral internal thoracic artery T grafting in 51 patients. The T graft was made by anastomosing the free right internal thoracic artery to the in-situ left internal thoracic artery. Average patient age was 63.5 +/- 9.9 years, and the average number of anastomoses per patient was 3.6 +/- 0.9. In 35 patients, the right gastroepiploic artery (21 anastomoses in 20 patients), radial artery (1 anastomosis), free left internal thoracic artery (1 anastomosis) and saphenous vein graft (14 anastomoses in 13 patients) were used as additional bypass conduits. RESULTS: Hospital mortality was 0%. The morbidity of stroke was 1.9% (1 patient) and deep sternal infection 0%. Patency of the in-situ left internal thoracic artery was 49/50 anastomoses (98%) and that of the free right internal thoracic artery 81/84 anastomoses (96.4%). Mid-term coronary angiography in 7 patients demonstrated patent anastomosis of the T graft. Acute myocardial infarction unrelated to graft failure occurred in 2 patients during follow-up. Other patients were evaluated by exercise stress tests every year and none exhibited myocardial ischemia in the areas of T graft coronary revascularization. Three-year actuarial survival rate was 100% and freedom from cardiac events 96%. CONCLUSIONS: The bilateral internal thoracic artery T graft provides satisfactory early and mid-term outcomes in properly selected patients.     

Reoperative off-pump subclavian-coronary artery bypass grafting in an elderly patient with left internal thoracic artery stenosis]

A 80-year-old Japanese female was diagnosed to have angina pectoris and admitted to our hospital. She had been operated on with mitral valve replacement and coronary artery bypass grafting to right and circumflex coronary artery 4 years before. The coronary angiogram showed significant stenosis with severe calcification in the left anterior descending coronary artery, and it was unsuitable for catheter intervention. The patient also had stenotic left internal thoracic artery and multiple cerebral infarction, but successful off-pump subclavian-coronary artery bypass grafting using saphenous vein graft through small thoracotomy was performed without new neurological deficit. This procedure is useful for patients with left internal thoracic artery unsuitable for MIDCABG, due to quality, size, or injury during preparation.     

Has the in situ right internal thoracic artery been overlooked? An angiographic study of the radial artery, internal thoracic arteries and saphenous vein graft patencies in symptomatic patients.

OBJECTIVE: The right internal thoracic artery is being used infrequently despite favorable observational angiographic data. Conversely, the radial artery utilization has increased with only limited data available. The purpose of this paper is to re-evaluate the roles of the right internal thoracic artery and the radial artery grafts. METHODS: We reviewed all ischemia-directed coronary angiographic procedures from January 1996 to December 2003. A total of 219 patients had primary coronary artery bypass grafting with an internal thoracic artery and a radial artery as two of the bypass grafts. Six hundred and seventy-nine (679) graft angiograms (45 saphenous vein, 363 radial artery, 54 right internal thoracic artery and 217 left internal thoracic artery) were studied. The mean period from operation to re-angiogram was 1104+/-761 days. Angiographic outcomes were divided into groups as: (1) patent (<50% stenosis) or (2) failed (>or=50% stenosis, string sign or occluded). A generalized linear mixed model was used to analyze predictors of graft patency. Turnbull's estimates of cumulative patency were used to compare graft failure rates over time. RESULTS: A total of 632/679 (93%) grafts were patent and 47/679 (7%) grafts had failed. Empirical saphenous vein graft patency was 40/45 (89%), radial artery patency 329/363 (91%), right internal thoracic artery patency 51/54 (94%) and left internal thoracic artery patency 212/217 (98%). Pairwise comparisons of patency from the generalized linear mixed model were: LITA>RITA, OR=1.5 (P=0.5); LITA>RA, OR=5.7 (P<0.001); LITA>SV, OR=6.5 (P<0.001); RITA>RA, OR=3.9 (P=0.01); RITA>SV, OR=4.4 (P=0.01); RA>SV, OR=1.1 (P=0.7). Five-year patency estimates from the Turnbull's model were the left internal thoracic artery (95.9%), right internal thoracic artery (91.2%), the radial artery (90.6%) and the saphenous vein (81.8%). CONCLUSIONS: Consideration should be given to the routine use of both internal thoracic arteries for coronary artery bypass grafting. When additional grafts are required, there is no evidence to suggest that either the radial artery or saphenous vein is superior.     

Healing of the intimal dissection of the internal thoracic artery graft

We report healing of the intimal dissection of an internal thoracic artery graft. Triple coronary artery bypass grafting was performed using left internal thoracic artery and saphenous vein grafts. One month after operation, the intimal dissection of the internal thoracic artery graft was clearly visible by coronary angiography; however, after 1 year of only medical treatment consisting of warfarin, ticlopidine, and nitrate, the intimal dissection was undetectable by coronary angiography.     

Urgent coronary artery bypass graft operation of a patient with acute anterior myocardial infarction,congenital right coronary artery to main pulmonary artery fistula and left hilar hamartoma of the lung

BACKGROUND: Coronary artery fistulas are rare congenital or acquired coronary artery anomalies that can originate from any of the three major coronary arteries and drain into all the cardiac chambers and great vessels. METHODS (CASE REPORT): A 67-year-old male patient administered to the emergency department with a severe unstable angina pectoris. Patient underwent a three-vessel coronary artery bypass graft surgery, liga-clip occlusion of coronary artery to pulmonary artery fistula and a direct diagnostic punch biopsy from the left hilar mass lesion. RESULTS: No complications were encountered postoperatively. The patient was discharged on postoperative day eleven with a referral to the thoracic surgery department for further treatment of his lung tumor. CONCLUSIONS: In this report we present successful combination of an urgent coronary artery bypass graft operation in acute anterior myocardial infarction status with concomitant pathologies of congenital right coronary artery to main pulmonary artery fistula and left hilar mass lesion of the lung.