Sequential internal mammary artery bypass for multiple coronary stenoses

Long-term studies (10 years) show a 50 per cent patency rate of saphenous vein autograft and 95 per cent patency rate of internal mammary artery coronary bypass grafts. In some situations (after saphenous vein stripping, varicose and fibrotic veins) it is not possible to use venous grafts and the internal mammary artery has to be used. However, the internal mammary artery is usually only used for revascularisation of the left anterior descending artery. Sequential internal mammary artery bypass is a technique which can be used for revascularizing the left anterior descending artery. Seven men aged 44 to 68 years (average 55 years) were operated between November 1983 and February 1985. These patients had clinically stable (4 cases) or instable (3 cases) angina. Two patients had previously undergone bilateral saphenous vein stripping and one patient a terminal anastomosis on the left anterior descending and a latero-lateral anastomosis on the diagonal artery. Three patients had an associated venous bypass graft and one patient also underwent aortic valve replacement. There were no cases of postoperative myocardial infarction. Five control angiographies were carried out during the first postoperative month. In 4 patients the internal mammary graft ant the latero-lateral and termino-lateral anastomoses were patent. In the other case, the latero-lateral anastomosis and the diagonal artery was occluded but the internal mammary graft and the termino-lateral anastomosis on the left anterior descending artery were patent. The average follow-up period is now 18 months: there have been no recurrences of chest pain or any ECG changes. These results show that internal mammary artery bypass grafting is a delicate procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fistulous connection between internal mammary graft and pulmonary vasculature after coronary artery bypass grafting: a rare cause of continuous murmur

A 58-year-old male who had undergone coronary artery bypass grafting (CABG) using left internal mammary artery and a sequential saphenous vein graft 2 years ago presented with new onset angina. His initial physical examination revealed an unexpected continuous murmur over the left sternal border, and two-dimensional echocardiography has failed to identy the cause. Cardiac catheterization then performed and revealed patent left internal mammary artery and saphenous vein grafts. Besides, selective injection of the left internal mammary artery graft also showed a fistula formation between left internal mammary artery graft and pulmonary vasculature of the left upper lobe. He was managed conservatively because of the severely diseased left anterior descending artery distal to internal mammary artery anastomosis and low pulmonary artery pressure. The development of fistulous connection between internal mammary artery and pulmonary vasculature is an extremely rare complication following CABG. Patients with such fistulae usually present with chest pain due to coronary steal syndrome. A new heart sound, especially a continuous murmur, may be detected during physical examination. Surgical correction is indicated in the event of refractory angina, growing fistula causing heart failure or endarteritis. Otherwise, a conservative approach with instruction of the patient for prophylactic precautions of subacute bacterial endocarditis may be recommended for asymptomatic patients.     

10-year results of anastomoses of the left internal mammary artery to the anterior interventricular artery. Angiographic and radionuclide controls

The long term patency of left internal mammary artery graft is better than that of saphenous vein graft. The aim of this study was to determined if this high patency rate was accompanied by a satisfactory myocardial perfusion. Among 143 patients treated with an internal mammary artery graft on the left anterior descending artery between 1972 and 1976, 42 patients underwent coronary angiogram and exercise tomoscintigraphy (thallium 201) over 10 years after surgery. The left internal mammary artery was patent in 92% without any atheromatous lesions. The myocardial perfusion in the area supplied by the left anterior descending artery was normal in 74%. A slight ischemia appeared during exercise in 19% without any clinical symptoms. This long term study shows excellent anatomical results correlated with a good myocardial perfusion during exercise in most cases.     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency.

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of the patency of left internal mammary artery graft by transcutaneous Doppler flow velocity analysis]

OBJECTIVE: To analyze the features of Doppler flow velocity curve of left internal mammary artery by-pass grafts in relation with their permeability as assessed by selective angiography. METHODS: Twenty-five consecutive patients with a left mammary artery graft were studied by angiography and transcutaneous Doppler technique. From the Doppler tracings, peak velocity and time-velocity integral of the systolic and diastolic components were determined. Patency of the graft and the characteristics of the distal native coronary artery were evaluated at angiography. RESULTS: Doppler flow signal was obtained in 23 (92%) of 25 analyzed patients. The graft was angiographically patent in 17 (68%) of 25 patients; in 15 (88%) of them the Doppler flow velocity signal was mainly diastolic and in only 2 (12%) it was predominantly systolic. In 8 (32%) of the 25 patients the graft was angiographically occluded, 6 (75%) of these patients showing a predominantly systolic Doppler signal, while the remaining 2 (25%) patients were those in whom the signal could not be elicited. Sensitivity and specificity of a predominantly diastolic Doppler flow pattern for the presence of graft patency was 88% and 100% respectively, with a predictive positive value of 100% and a negative one of 80%. CONCLUSIONS: Doppler flow velocity pattern of internal mammary artery by-pass grafts is related with patency of the graft, the presence of a predominantly diastolic curve being highly indicative of a patent graft.     

Urgent trans‐axillary valve‐in‐valve procedure using the Edwards 16‐F expandable introducer

Transcatheter aortic valve implantation could represent an alternative option to conventional surgery in high‐risk patients with degeneration of aortic bioprosthesis. Herein, we report the performance of a valve‐in‐valve procedure in urgent conditions and via the left axillary artery in a patient with patent left internal mammary artery coronary graft. A 23‐mm Edwards Sapien^® transcatheter valve was deployed within a 23‐mm Edwards Magna Ease bioprosthesis through the novel Edwards 16‐F expandable introducer. In this non‐elective case, the expandable introducer allowed a safe procedure, reduced the risk of subclavian injury, and preserved the left internal mammary artery graft flow. © 2012 Wiley Periodicals, Inc.     

Success of internal mammary bypass grafting can be assessed intraoperatively using myocardial contrast echocardiography

To determine whether the success of internal mammary artery bypass grafting can be assessed intraoperatively using myocardial contrast echocardiography, sonicated Renografin-76 was injected into the aortic root of 11 dogs during the delivery of cardioplegic solution. Studies were performed with the left anterior descending coronary artery patent and totally occluded, and after internal mammary artery bypass grafting distal to the occluded vessel. Flow rate during cardioplegia was constant for all three stages in each experiment. Myocardial contrast echocardiography clearly demonstrated homogeneous myocardial perfusion with the left anterior descending coronary artery patent, lack of perfusion in the left anterior descending artery bed during its occlusion and excellent perfusion of the occluded bed after internal mammary artery bypass grafting distal to the occlusion in 10 of the 11 dogs. In one dog, the bypass graft was technically inadequate and contrast opacification was not noted in the left anterior descending artery bed after internal mammary artery bypass grafting. The exponential function C(t) = Ae-alpha t + Be-beta t was fitted to computer-derived time-intensity curves from the myocardium, where alpha denotes contrast washout and beta denotes contrast appearance. Respective values for alpha and beta (mean + 1 SD) were similar for the patent left anterior descending coronary artery and after internal mammary artery bypass grafting distal to the occluded artery (0.11 +/- 0.10 versus 0.10 +/- 0.10, and 2.5 +/- 2.4 versus 1.1 +/- 0.56). In conclusion, myocardial contrast echocardiography has potential for intraoperative assessment of the adequacy of coronary artery bypass grafting.     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency. Therefore, an angiographically occluded internal mammary graft may be only functionally occluded and reversible even when the occlusion is demonstrated several days apart.     

Internal Mammary Artery Graft Dissection: A Case-Based Retrospective Study and Brief Review

The left internal mammary artery is the preferred graft for treating left anterior descending coronary artery disease. Dissection is a rare but grave sequela of internal mammary artery graft angiography. The available medical literature is scant, perhaps as a result of under-reporting.We report a case in which dissection of the internal mammary artery graft occurred during diagnostic angiography, and we discuss its management. In addition, we review the available literature and provide a retrospective analysis of the data from our own catheterization laboratory. In our single-center analysis of 542 cases of selective internal mammary artery graft angiography, we found only the single case of internal mammary artery graft dissection (0.2%) that we report here. Our review of the literature revealed 7 reported cases of internal mammary artery graft dissection, 3 of which were iatrogenic. There were no identifiable risk factors for such dissection. After treatment with angioplasty and stenting, all patients had good outcomes during follow-up.     

The brachial artery method to transluminal internal mammary artery angioplasty

A new catheter technique to perform angioplasty of the right or left internal mammary artery coronary graft utilizing the brachial artery approach is described. Utilization of the ipsilateral brachial artery permitted cannulation of the internal mammary artery with preformed polyurethane Teflon-lined guide catheters. The coronary dilatation catheter was passed through the guiding catheter into the internal mammary artery. This technique permitted successful access into the ipsilateral mammary artery in eight patients, the left internal mammary artery graft in five and the right in three patients. The angioplasty procedure was successfully performed in seven of eight cases (spasm of the left internal mammary artery precluded successful dilatation catheter passage in one case). No brachial artery complications were encountered. In two cases, angioplasty was successfully performed in additional coronary vessels. Follow-up of 1-16 months (mean: 7.7 months) revealed no clinical evidence of restenosis. The ipsilateral brachial artery approach utilizing preshaped guiding catheters for visualization and introduction of dilatation catheters into the internal mammary artery graft is a safe and successful approach, and it is an acceptable alternative to the femoral technique.     

An unusual cause of recurrent angina two years after coronary artery bypass grafting: fistula between internal mammary artery graft to pulmonary vasculature.

A 55-year-old man developed recurrent angina pectoris 2 years after coronary artery bypass grafting. Cardiac catheterization demonstrated that the venous grafts were patent, but selective left internal mammary angiogram showed multiple fistulous connections between the internal mammary artery and the pulmonary vasculature of the left upper lobe. After surgical correction of the fistula, the angina resolved. Only three previous cases of acquired internal mammary artery graft fistulas draining to the pulmonary vasculature have been described. The etiology, clinical presentation, and management of an internal mammary artery fistula to the pulmonary vasculature are discussed.     

Ischemia induced by coronary steal through a patent mammary artery side branch: A role for embolization

Non-occlusion of the internal mammary artery side branches may cause ischemia due to flow diversion after coronary artery bypass grafting.The authors present the case of a 67-year-old man with recurrent angina after undergoing myocardial revascularization with a left internal mammary artery to left anterior descending bypass. He presented with impaired anterior wall myocardial perfusion in the setting of a patent left internal mammary artery side branch. Effective percutaneous treatment was carried out through coil embolization, with improved flow and clinical symptoms, confirmed through ischemia testing.Coronary steal through a patent mammary artery side branch is a controversial phenomenon and this type of intervention should be considered only in carefully selected patients.     

Kinking of internal mammary grafts: report of two cases and surgical correction

Two patients who underwent left internal mammary artery (IMA) anastomoses to the left anterior descending artery (LAD) developed sudden angina associated with anterior ischemic changes on EKG in the early postoperative period, one at 4 hr and the other at 3 days following operation. Digitalized arteriography via retrograde injection of the left brachial artery revealed the IMAs, which were partially obstructed because of looping and Kinking, although the anastomoses to the LAD were patent. Reoperation was successful in relieving obstruction by reducing these abnormalities and resulted in an uncomplicated postoperative course following the second operation. Discussion of the etiology, radiological technique of diagnosis, correction, and prevention of this cause of internal mammary graft failure is presented.     

Use of 2 internal mammary arteries in coronary bypass. Combination with a bypass using the gastroepiploic artery in 2 cases

Coronary revascularisation by bilateral internal mammary artery grafting was performed in 39 patients. The left internal mammary was anastomosed to the left anterior descending (N = 22), the left lateral (N = 12) or diagonal artery (N = 5). The right internal mammary was implanted on the right coronary (N = 17), the left anterior descending (N = 16), the left lateral (N = 3) or diagonal artery (N = 3). In two cases, the inferior myocardial segments were revascularised by grafting the gastroepiploic artery. Three patients died and one patient had signs of postoperative myocardial infarction. Respiratory complications, usually mild, occurred in 5 patients. Bilateral internal mammary artery grafting should be reserved for: 1) young patients, 2) those without usable leg veins (varicose veins, previous stripping or coronary bypass surgery). The gastroepiploic artery is a useful arterial graft for revascularizing regions of the heart inaccessible to the internal mammary arteries.     

Myocardial Protection during Reoperative Cardiac Surgery: Early Experience with a New Technique

We recently introduced a new adjunct to myocardial preservation in patients with a patent left internal mammary artery graft who were undergoing reoperative cardiac surgery. The purpose of this study was to review our early experience with this technique.The technique consists of preoperative insertion of a suitably sized angioplasty balloon catheter into the proximal part of the graft under fluoroscopic guidance. Intraoperative inflation of the balloon results in occlusion of the graft during aortic cross-clamping. We have used this technique in 9 patients. The case records of these patients were retrospectively reviewed.There were 5 men and 4 women with a mean age of 71 ± 11 years and a mean Euro-SCORE of 10 ± 3. The median time interval from previous cardiac operation to reoperation was 6 years (interquartile range, 2–11 yr). After the balloon catheter was inserted successfully into the left internal mammary artery graft, the balloon was inflated intraoperatively for successful occlusion of the graft in all patients. There was no in-hospital death, and no significant complications were observed.The early results of this technique seem favorable. A prospective randomized study is needed in order to evaluate the potential advantages of this method over other techniques of myocardial protection during cardiac reoperations.Key words: Angioplasty balloon, catheterization, peripheral, coronary artery bypass, graft occlusion, vascular, internal mammary artery, reoperation/methods, vascular patencyReoperative cardiac surgery is becoming increasingly common but is associated with a higher risk of perioperative morbidity and death than is primary surgery.^1,2 This increased risk is partly due to the characteristics of the patient population, since patients undergoing reoperations tend to be older and have more comorbid conditions and worse cardiac function, but it is also due to the complexity and technical challenges of reoperations.^1,2 One of the common technical challenges of cardiac reoperations is the dissection and external control of a patent left internal mammary artery (LIMA) graft in patients who have undergone previous coronary artery bypass surgery. Control of this artery becomes necessary when cardioplegic techniques are used for myocardial protection, because blood flowing through a patent graft would otherwise wash away the cardioplegic solution. Mobilization and external clamping of a patent LIMA graft can cause injury to the vessel, leading to adverse short- and long-term outcomes. Angioplasty balloon occlusion of the LIMA graft—an interesting alternative to external clamping—was first described in 2001 by Grinda and colleagues.³ The principle of the technique is preoperative placement of a suitably sized angioplasty balloon in the LIMA graft followed by intraoperative inflation of the balloon during aortic cross-clamping. The purpose of this retrospective study was to review our early experience with this technique.     

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)     

Relocation of the internal mammary artery graft in a case of coronary-subclavian steal

Reverse flow in the internal mammary artery coronary graft in the presence of subclavian stenosis is rare. We describe a 67-year-old man who 7 years after coronary artery surgery was admitted with left subclavian artery stenosis and retrograde flow in the pedicled left internal mammary artery graft. Subsequent redo triple coronary artery bypass grafts included regrafting the left internal mammary artery graft to a new vein conduit.     

The internal mammary artery in myocardial revascularization

Internal mammary artery by-pass graft is a very usefull alternative to venous by-pass graft for myocardial revascularization. From February 1982 up to August 1984, 111 patients with coronarosclerosis have been operated on with left internal mammary artery. Right internal mammary artery has been also used in 2 cases. Left internal mammary artery has been used as a sequential graft 13 times. Vein grafts have been associated in more than 2/3 of the patients who had surgery with internal mammary artery and the mean of anastomoses per patient was 2.9. Five patients had a perioperative myocardial infarction and one an infarction shortly after the operation. Ten patients had immediate reoperation: 5 for postoperative bleeding, 2 for arterial graft anastomosis occlusion, 2 for sudden ST elevation and 1 for acute myocardial infarction. Only one patient died for acute myocardial infarction post-operatively, following coronary artery spasm. Eighty-six patients have been followed-up 3 to 31 months after surgery. Advantages and limits of this surgical technique are discussed.     

The split radial technique: an alternative to the Y-graft for total arterial myocardial revascularisation

There is evidence that the use of Y-grafts attached to the left internal mammary artery - to - left anterior descending artery graft may compromise the patency of the distal limb of the left internal mammary artery. We describe a technique (split radial technique) that avoids the use of Y-grafts by constructing two aorto-coronary grafts from a single radial artery. The split radial technique requires the harvesting of the radial artery in its entirety from the brachial bifurcation to the radial styloid. The first radial artery distal anastomosis is performed and the required length of conduit is determined. The conduit is transected, leaving a sufficiently long radial segment for a second aorto-coronary graft. A clinical follow-up 41 weeks after surgery of the first 37 patients in whom the split radial technique was used showed no deaths or major complications. This suggests that the split radial technique is a useful and safe way to maximise the use of radial artery conduit and to avoid the potential risk of compromising internal mammary artery patency with Y-grafts. There is evidence that the use of Y-grafts attached to the left internal mammary artery may compromise the patency of the distal limb of the left internal mammary artery. We describe the split radial technique of constructing two aorto-coronary graft segments from a single radial artery that can be used to avoid the use of Y-grafts.     

A saphenous vein graft aneurysm with fistula development to the right atrium: Surgical management of a rare bypass graft complication

A patient presented late following coronary artery bypass surgery with recurrent angina. Investigations revealed a saphenous vein graft aneurysm, which subsequently formed a fistula with the right atrium. This was managed by surgical excision and repair followed by regraft of the run-off territory. Intraoperatively, the left internal mammary artery, a patent graft to the left anterior descending artery, was isolated from the circulation during aortic cross-clamping by preoperative placement of a percutaneous balloon catheter within this graft. Surgery was successful and the patient was discharged symptom-free one week later.