Left internal mammary artery intervention: the left radial approach with a new guide catheter

Coronary intervention involving left internal mammary bypass grafts is an increasingly common challenge for the interventionalist. Although successful in a high percentage of patients, the femoral approach may be technically challenging. The shorter, more direct approach from the left radial artery has potential advantages in these cases. The present study evaluated our experience using a new left transradial internal mammary guide catheter. Angiography alone was successfully performed with the catheter in 40 patients. In an additional 10 patients, internal mammary artery interventional procedures were performed. Angioplasty alone was performed in five patients. Five patients underwent coronary stenting within the internal mammary artery or native left anterior descending artery. Guide catheter backup was satisfactory and angioplasty catheters and/or stents could be advanced to the target lesion with minimal difficulty. No procedural complications occurred. The left radial artery access site is an excellent approach for left internal mammary intervention.     

A comparison of morphologic and angiographic findings in long-term internal mammary artery and saphenous vein bypass grafts

Internal mammary artery grafts are currently considered the conduits of choice for myocardial revascularization. Comparisons of long-term morphologic changes in internal mammary artery grafts and saphenous vein grafts and correlation with premortem angiography have not been reported. Eighteen internal mammary artery and 15 saphenous vein grafts that had been in place for 12 to 118 months (mean 56) in 18 patients were removed either surgically or at necropsy and examined histologically. Premortem angiograms were performed within 1 month of histologic study in 15 of these patients. Fibrointimal proliferation was more frequent in internal mammary artery than in saphenous vein grafts 8 [( 44%] of 18 versus 4 [27%] of 15; p = NS). In contrast, atherosclerosis was common in saphenous vein grafts but was extremely rare in internal mammary artery grafts (10 of 15 versus 1 of 18; p = 0.01). A good correlation was noted between the degree of narrowing estimated by angiographic and histologic measurements in both internal mammary artery grafts (d = 0.90) and saphenous vein grafts (d = 0.71). Accelerated atherosclerosis did not occur in internal mammary artery grafts, but was common in saphenous vein grafts. Fibrointimal proliferation was commonly associated with graft narrowing in internal mammary artery grafts and may be an important factor in late graft closure. This study also confirms that internal mammary artery grafts have greater longevity compared with saphenous vein grafts.     

The string phenomenon: an important cause of internal mammary artery graft failure

Internal mammary arteries are the grafts of choice for coronary artery bypass because they are generally free of atherosclerosis and they have high patency rates as grafts. There are, however, increasing reports of graft failure due to diffuse or distal narrowing, known as the string phenomenon. From June 1999 to October 1999, we prospectively reviewed all cases of internal mammary artery angiography at our institution. Twenty-eight cases of internal mammary artery graft failure were identified (M:F, 15:13; mean age, 62 years) out of 261 patients who had undergone internal mammary artery grafting at any institution, including ours. The mean interval between coronary artery bypass and re-angiography was 35 months. There was evidence of competitive flow in 81% (22 of 27) of patients whose internal mammary grafts had developed the string sign. This observational study supports the hypothesis that competitive flow predisposes internal mammary grafts to the string phenomenon. Given the high frequency of competitive flow situations amongst patients with internal mammary artery graft failure, caution should be exercised in the anastomosis of the internal mammary artery to recipient vessels that are less than severely stenosed.     

Internal mammary artery versus saphenous vein graft. Comparative performance in patients with combined revascularisation.

Thirty three patients with coronary artery disease undergoing combined myocardial revascularisation with internal mammary artery and saphenous vein grafts underwent angiographic studies up to 10 years after operation. Each patient had one internal mammary artery graft and one or more saphenous vein grafts. Eleven symptom-free patients, studies one month to five years (mean 1.9 years) after operation, had intact internal mammary artery and saphenous vein grafts in a good state of preservation. Of the six patients developing symptoms within the first year after surgery, three had evidence of poor flow in the internal mammary artery graft because of large side branches and the other three had stenosis or occlusion of the saphenous vein grafts. Sixteen patients developed symptoms after several years free of symptoms and were studied three to 10 years (mean six years) after operation. Of the 23 saphenous vein grafts in this group, 17 (74%) were either occluded or severely stenosed and six (26%) were in good condition. One internal mammary artery graft was occluded and the remaining 15 were in good condition. Saphenous vein graft failure was the predominant cause of late development of symptoms in patients with combined revascularisation. Long term performance of the internal mammary artery grafts is far superior to the saphenous vein grafts.     

Myocardial revascularization using both internal mammary arteries. Clinical results and surgical strategy

To improve the benefits from coronary artery grafting with internal mammary artery (IMA) several technical manoeuvres and methods have been developed to increase the number of coronary arteries and their branches that can be bypassed with internal mammary arteries. Between November 1985 and December 1986, 50 patients underwent a surgical myocardial revascularization procedure using both internal mammary arteries by single or sequential anastomoses and supplemental saphenous vein graft. In 42% of these patients complete revascularization was achieved employing only internal mammary artery grafts. One hundred and twenty-six internal mammary artery grafts (77% of the total coronary bypass performed), were placed. One patient developed perioperative myocardial infarction. Reparative surgery to control immediate post-operative bleeding was required in two patients. Post-operative coronary angiography performed in 30 patients showed all patent internal mammary artery grafts but one. No late deaths occurred. Mean follow-up of 10 months was complete in 50 patients, of whom 94% are symptom free. We conclude that bilateral internal mammary artery grafting can be performed with low operative risk and can provide excellent long-term functional improvement and survival employing only high patency arterial conduit. Moreover, it doesn't significantly increase surgical morbidity.     

An update on internal mammary artery grafting for coronary artery disease

PURPOSE OF REVIEW: To describe recent results regarding the use of the internal mammary artery for coronary artery bypass grafting with emphasis on bilateral internal mammary artery grafting, patency, resistance to atherosclerosis, skeletonisation, composite arterial grafts, flow measurement, vasodilatation, and non-invasive imaging techniques. RECENT FINDINGS: Coronary artery bypass grafting plays an important part in coronary revascularisation and seems to be associated with a survival benefit in comparison with percutaneous coronary intervention. After 10 years, internal mammary arteries demonstrate better patency than vein grafts except when grafting moderately stenosed right coronary arteries. Bilateral internal mammary artery grafting increases survival further, but carries a higher risk of sternal complications. Skeletonisation may reduce this risk. The internal mammary arteries are used increasingly as composite arterial grafts and this technical solution should no longer be considered experimental. Perioperative flow measurement by the transit-time method is recommended while postoperative echocardiography represents an accurate method for evaluation of flow in internal mammary artery grafts. Multi-detector computed tomography allows for accurate assessment of all types of bypass conduits and native coronary arteries. At present, magnetic resonance imaging of internal mammary artery patency and flow is possible. SUMMARY: Newer studies confirm earlier data with respect to improved long-term survival when using internal mammary artery grafting, and this survival benefit is superior to percutaneous coronary intervention treatment. Bilateral internal mammary artery grafting improves survival further. Skeletonisation of the internal mammary artery provides extra length of grafts for complete arterial revascularisation. Non-invasive imaging techniques are increasingly sophisticated and may change the referral pattern for patients with coronary artery disease to either percutaneous coronary intervention or coronary artery bypass grafting.     

Coronary artery bypass with bovine internal mammary artery graft

Ten of 1,025 patients undergoing coronary bypass surgery received one or two bovine internal mammary artery grafts. Surgery consisted in quadruple coronary bypass in 1 case, triple coronary bypass in 3 cases and double coronary bypass in 6 cases using 4 autologous saphenous vein grafts, 6 autologous internal mammary artery grafts and 13 bovine internal mammary artery grafts. It was necessary to use bovine internal mammary artery grafts because of total bilateral venous stripping in 5 patients, diffuse, bilateral varicose veins in 4 patients and because of the insufficient length of the vein in 1 patient. Short and medium-term (12 months) angiographic studies of the bovine grafts showed 5 occluded grafts, 2 proximal graft stenoses, and 1 patient graft up to the time of his death of extracardiac causes, with a maximum follow-up of 13 months. One of these 10 patients died in the early postoperative period of extracardiac causes with a patent bovine coronary graft. Another patient died in the 5th postoperative month during reoperation motivated by occlusion of the two implanted bovine coronary grafts. The other 8 patients are alive and stable from the coronary view point. Bovine internal mammary artery grafts may be used to manage an acute episode of coronary insufficiency by providing the time for the collateral circulation to develop but it does not provide a complete and durable method of revascularisation. Their use should therefore be reserved for exceptional cases.     

Internal mammary artery versus saphenous vein graft. Comparative performance in patients with combined revascularisation

Thirty three patients with coronary artery disease undergoing combined myocardial revascularisation with internal mammary artery and saphenous vein grafts underwent angiographic studies up to 10 years after operation. Each patient had one internal mammary artery graft and one or more saphenous vein grafts. Eleven symptom-free patients, studies one month to five years (mean 1.9 years) after operation, had intact internal mammary artery and saphenous vein grafts in a good state of preservation. Of the six patients developing symptoms within the first year after surgery, three had evidence of poor flow in the internal mammary artery graft because of large side branches and the other three had stenosis or occlusion of the saphenous vein grafts. Sixteen patients developed symptoms after several years free of symptoms and were studied three to 10 years (mean six years) after operation. Of the 23 saphenous vein grafts in this group, 17 (74%) were either occluded or severely stenosed and six (26%) were in good condition. One internal mammary artery graft was occluded and the remaining 15 were in good condition. Saphenous vein graft failure was the predominant cause of late development of symptoms in patients with combined revascularisation. Long term performance of the internal mammary artery grafts is far superior to the saphenous vein grafts.     

Cannulation of a LIMA graft via the right brachial arterial route using a MANI catheter: an alternative approach

Some different revascularization methods including coronary artery bypass surgery can be performed in the treatment of coronary artery disease. Saphenous vein grafts and/or arterial grafts including left internal mammary artery (LIMA) can be implanted during coronary bypass surgery. It is necessary to perform cannulation of the LIMA, in order to diagnose and treat these patients. In addition to conventional internal mammary artery catheters, several types of catheters can be used for this purpose. In general, LIMA catheterization via the femoral artery has been preferred over other methods. However, the right brachial arterial approach can be mandatory in some rare conditions. In this report, we describe an alternative method to the conventional techniques of the LIMA graft angiography via the right brachial arterial approach using a MANI catheter. According to our knowledge, no data are available using the MANI catheter for this purpose in the current literature.     

Percutaneous transluminal angioplasty involving internal mammary artery bypass grafts: a femoral approach

Percutaneous transluminal coronary angioplasty is an effective technique for the treatment of selected patients with ischemic heart disease due to coronary artery stenosis. Successful angioplasty in saphenous vein bypass grafts has been documented, but little experience has been reported using angioplasty in internal mammary artery to coronary artery bypass grafts. Nine of ten patients with stenosis in the internal mammary artery to coronary artery anastomosis or in the coronary vessel distal to the anastomosis site were successfully treated with angioplasty. One patient developed restenosis 1 month after the procedure, and a repeat angioplasty was successful. In one patient, the balloon catheter could not be advanced through the left internal mammary artery to the stenosis site. Technical features of internal mammary artery angioplasty are discussed, including the use of specially designed guiding wires, guiding catheters, and balloon catheters that facilitate angioplasty involving internal mammary arteries from the femoral approach.     

Percutaneous transluminal angioplasty in patients with subclavian stenosis and internal mammary grafts

Subclavian artery stenosis is an uncommon cause of myocardial ischaemia in patients with internal mammary artery grafts. Coronary subclavian steal and impaired flow through the graft are the two mechanisms implied. We report 2 patients with mammary artery grafts in whom reappraisal of anginal symptoms was related to the presence of proximal subclavian stenoses located just before the origin of the mammary artery grafts. Both patients were successfully treated by percutaneous angioplasty and stent implantation.     

Free arterial grafts

The use of free arterial grafts has increased since the late patency of free internal mammary artery grafts was found to approach that of pedicle internal mammary artery grafts. An intensified search for other suitable arterial grafts has resulted in reports on the use of free gastroepiploic artery grafts and free inferior epigastric artery grafts. Free arterial heterografts and free homograft saphenous veins have had very disappointing results in general. The lateral costal artery, when available, offers another possible arterial conduit in approximately 10% of patients. To effect a wider use of arterial conduits for coronary bypass grafts, a number of techniques have been devised to use the internal mammary artery and other arterial grafts as free grafts.     

Use of a pigtail catheter to engage a difficult internal mammary artery.

Increasing use of bilateral internal mammary arteries for coronary surgery will increase the number of interventions in these grafts. Such interventions may be technically challenging because of often tortuous and angulated vessels. We describe a technique to intubate an acutely angulated right internal mammary artery that was inaccessible with conventional catheters.     

Internal mammary artery graft for ischemic heart disease. Effect of revascularization on clinical status and survival.

Four hundred consecutive patients, 80 percent of whom had multiple vessel obstruction, received a single internal mammary artery graft (121 patients) alone or combined with vein grafts (279 patients) in 1971 and 1972. Four patients died during or within 30 days of the operation. Sixteen patients had intraoperative infarction; three died. Arteriography was performed postoperatively (mean 12 months) in 254 patients, and 248 of 261 internal mammary artery grafts (95 percent) and 195 of 237 vein grafts (82 percent) were patent. Follow-up was complete (mean interval 38 months); all 80 patients with single vessel disease are alive, and the 3 year survival rate for patients with double and triple vessel disease was 98.7 and 94.4 percent, respectively. Comparison of longevity of 741 patients who had received vein grafts in 1967 to 1970 with that of 400 patients with internal mammary artery grafts (1971 to 1972) indicates greater survival for the recent series (P less than 0.004). Factors responsible for improved survival include (1) reduced operative mortality, (2) fewer intraoperative infarctions, (3) more complete revascularization, and (4) higher patency rate of the internal mammary artery graft.     

Internal mammary artery bypass graft in reoperative myocardioal revascularization.

Thirty-two consecutive patients who earlier received indirect or direct myocardial revascularization underwent reoperation with one or more internal mammary artery grafts either alone or in combination with saphenous vein grafts. The main indication for reoperation was graft closure or progression of coronary atherosclerosis in nongrafted vessels, or both. Graft construction was performed under normothermic perfusion and anoxic arrest with interrupted suture technique. No intraoperative infarctions or hospital deaths occurred. All patients are alive after an average follow-up period of 20 months, and two thirds are asymptomatic. Arteriography after reoperation in nine patients revealed patency of eight of nine internal mammary artery and five of five secondary vein grafts. When angiographic and symptomatic indications for reoperation exist, the internal mammary artery bypass graft has become a valuable alternative, particularly for patients with small coronary vessels or previous vein graft failure.     

Combined two-dimensional and Doppler echographic examination of internal mammary artery grafts from the supraclavicular fossa.

The noninvasive examination of internal mammary artery grafts is gaining importance with the increasing use of this vessel in the surgical treatment of coronary atherosclerosis of the left anterior descending artery. We studied 36 patients (37 internal mammary artery grafts) with combined two-dimensional and pulsed Doppler echography from the supraclavicular fossa. Adequate visualization and Doppler signals were obtained in 95% of arterial grafts. Twenty-four grafts leading to an area without evidence of old myocardial infarction or ischemia and 10 grafts leading to an area of old myocardial infarction but without evidence of ischemia on exercise showed a significant decrease of the peak systolic velocity and of the peak systolic velocity/peak diastolic velocity ratio as compared to the controls, which consisted of the contralateral internal mammary arteries in situ. One patient with a distally subtotally occluded mammary artery graft had a flow pattern different from the other bypassed mammary arteries. It seems that combined two-dimensional and pulsed Doppler echography is a useful method to evaluate the functional status of internal mammary artery grafts.     

Internal mammary arteriography: a new catheter technique by right brachial approach

A technique for catheterization of both internal mammary arteries (IMAs) by right brachial approach is described. A special preformed catheter was used in 75 patients with coronary artery disease, including ten patients with direct IMA grafts. No complications occurred. The IMAs were studied to examine the question of their usefulness in direct myocardial revascularization. There were individual variations in the size of IMAS with poor correlation to age (r = -0.432)) and body surface area (r = 0.517). Seventy percent of the women had adequate IMAs. The IMA diameter was equal to or larger than the left anterior descending coronary artery (LAD) in 72% and the right coronary artery (RCA) in 34% of comparisons. Of the ten patients with direct IMA grafts, three instances of large side branches were seen. These branches appeared to carry large flows at the expense of the grafted coronary artery. Preoperative internal mammary arteriography should be done if the use of this vessel is contemplated in direct myocardial revascularization to assure the use of an IMA of adequate caliber compared to the recipient coronary artery. The side branches should be meticulously ligated during the operation.     

Comparison of coronary hemodynamics in patients with internal mammary artery and saphenous vein coronary artery bypass grafts: a noninvasive approach using combined two-dimensional and Doppler echocardiography

Blood flow in bypass grafts and recipient left anterior descending coronary arteries was evaluated with combined two-dimensional and Doppler echocardiography in 15 patients with an internal mammary artery graft and in 24 patients with a saphenous vein graft. Comparative studies of coronary hemodynamics were also performed regarding these two different grafting techniques. The graft vessel was detected in 11 (79%) of 14 patients with an internal mammary artery graft and in 20 (87%) of 23 with a saphenous vein graft. The recipient left anterior descending coronary artery was detected in 10 (67%) of the former group and 17 (71%) of the latter. The blood flow patterns obtained were generally biphasic, consisting of systolic and diastolic phases with higher velocity during diastole. The maximal diastolic flow velocity in internal mammary artery grafts was much higher than that in saphenous vein grafts. In patients with an internal mammary artery graft, the flow pattern characteristics within the recipient coronary artery were quite similar to those within the arterial graft, and flow velocities within the recipient coronary artery and the arterial graft were quantitatively almost identical. This outcome may contribute to the long-term patency seen in internal mammary artery grafts. On the other hand, the flow velocity in saphenous vein grafts was fairly low throughout the cardiac cycle. Flow velocity in the recipient coronary artery in patients with a saphenous vein graft was accelerated only in early diastole. As a result, the recipient coronary artery flow pattern and velocity differed substantially from those in the saphenous vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal angioplasty of left internal mammary artery grafts: two years' experience with a femoral approach

Percutaneous transluminal angioplasty via the femoral approach was attempted through internal mammary artery grafts in 11 patients who presented with distal anastomotic stenoses or distal native coronary artery stenoses and angina pectoris. The procedure was technically successful in 10 patients and no major complications occurred. During follow up there was one late death, but all 10 surviving patients showed functional improvement. Percutaneous transluminal angioplasty seems to be a safe and effective treatment for stenoses of internal mammary artery grafts. This is an effective technique for treating the increasing number of patients who are likely to present with stenoses of these grafts.     

ST-Segment elevation acute myocardial infarction due to severe hypotension and proximal left subclavian artery stenosis in a prior coronary artery bypass graft patient

Proximal subclavian artery stenosis may result in cardiac ischemia in coronary artery bypass graft patients with internal mammary grafts. We report a case of acute anterior myocardial infarction in such a patient who developed severe systemic hypotension. Symptoms and electrocardiographic changes resolved after proximal left subclavian artery stenting. Subclavian angiography should be considered in all prior coronary artery bypass graft patients with internal mammary grafts undergoing coronary angiography.