Coronary subclavian steal syndrome after internal mammary artery bypass grafting. A cause of severe postoperative recurrent myocardial ischemia

A 65-year-old underwent a triple bypass: internal artery mammary-descending coronary artery, aorta diagonal-lateral coronary (sequential). Three weeks later he started to have severe angina pectoris with ST depression in anterior EKG leads. A left transradial coronary angiography was performed. The examination showed a total occlusion of the left subclavian artery 2 cm after the aortic arch and a retrograde flow in the internal mammary artery (IMA). Via transfemoral approach, angiography showed the patency of the aorto-veinous sequential graft and a retrograde flow through anastomosis in the left mammary artery. The patient underwent a reimplantation of the IMA on the brachiocephalic artery. One month later the patient is doing well without chest pain. A coronary subclavian steal syndrome should be suspected in case of recurrent ischaemia after IMA bypass, particularly if there is more than 20 mmHg systolic pressure differential between the arms. Left transradial approach achieved diagnostic in case of total left subclavian artery occlusion.     

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.     

Noninvasive quantitative evaluation of the patency of internal mammary artery grafts to the left anterior descending coronary artery by transthoracic Doppler echocardiography

OBJECTIVES: Evaluation of left anterior descending coronary artery (LAD) flow by transthoracic Doppler echocardiography (TTDE) may allow assessment of anastomosis of the internal mammary artery (IMA) grafted to the LAD. This study tested the feasibility of TTDE to evaluate anastomotic stenosis of the IMA grafted to the LAD. METHODS: TTDE was performed in 66 patients (48 men and 18 women, mean age 67 +/- 10 years) with left or right IMA grafts to the LAD. The distal IMA flow at the anastomosis was visualized and the percentage stenosis was evaluated by the continuity equation using the anastomotic and pre-anastomotic flow velocity measured by TTDE as well as by angiography. If the anastomotic flow was not visualized by TTDE, the absence of augmented diastolic flow of the proximal IMA, by using the supraclavicular approach, with diastolic to systolic mean velocity ratio < 0.25 was considered as anastomotic occlusion. RESULTS: Anastomotic flow was visualized and the percentage stenosis was obtained by the continuity equation in 50 patients. In 4 of the remaining 16 patients, the proximal IMA flow by TTDE showed the occlusion pattern. In these 54 (82%) patients, the percentage stenosis by TTDE showed a significant correlation with that by angiography (r2 = 0.86, p < 0.0001). In all the remaining 12 patients with the patent proximal IMA pattern but without visualized anastomotic flow, the patency was confirmed by angiography. CONCLUSIONS: TTDE enables direct visualization and quantitative evaluation of the anastomotic patency in patients with IMA graft to the LAD.     

Creation of anastomoses between an extracardiac artery and the coronary circulation. Proof that myocardial angiogenesis occurs and can provide nutritional blood flow to the myocardium.

The purpose of this investigation was to determine whether blood vessels could develop de novo between an extracardiac artery and a collateral-dependent zone of the heart and to quantify the nutritive blood flow afforded by the new vessels. We also adapted the preparation so that angiogenically active agents could be chronically administered directly to the site of neovascularization in subsequent studies. To induce neovascularization between a systemic artery and the coronary circulation, the left internal mammary artery (IMA) was implanted in an intramyocardial tunnel in proximity to the left anterior descending coronary artery (LAD). A tube situated in the distal IMA connected to an implanted pump provided for continuous intra-arterial infusion at the site of angiogenesis. During the same procedure, an ameroid constrictor was placed on the proximal LAD, rendering its perfusion territory collateral dependent during a 2-3 week period. After 8 weeks, the functional capacity of the anastomoses established between the implanted IMA and the LAD territory was assessed by determining regional myocardial blood flow under basal conditions, during adenosine-induced vasodilatation, and during differential occlusions of the IMA and left circumflex coronary artery (LCCA). For all dogs, IMA occlusion decreased maximal LAD territory flow from 1.31 +/- 0.11 to 1.16 +/- 0.10 ml/min/g (p less than 0.005). Occlusion of the LCCA decreased LAD zone flow to 0.73 +/- 0.12 ml/min/g, whereas occlusion of the IMA in addition to the LCCA further decreased LAD zone flow to 0.42 +/- 0.11 ml/min/g (p less than 0.02). The IMA provided measurable nutritive blood flow in seven of 12 dogs, and in these dogs, the artery provided 30.0 +/- 2.5% of total LAD zone collateral conductance under conditions of maximal vasodilatation (range, 23-42%). We conclude that angiogenesis can occur between an implanted internal mammary artery and the native coronary circulation in dogs, providing modest nutritive blood flow to a collateral-dependent region. Further studies will be necessary to determine whether direct, local infusion of angiogenically active factors can enhance neovascularization and whether sufficient flow can be reliably supplied to make some variant of this approach clinically applicable.     

Coronary artery bypass grafting by utilizing the internal mammary artery graft in 100 Japanese patients

The internal mammary artery (IMA) grafting for myocardial revascularization was performed in 100 Japanese patients during a three-year period. There were 86 males and 14 females with the mean age of 58 +/- 9 (37 approximately 75 year-old). Unilateral IMA was used in 88 patients and bilateral IMA was used in 12 patients. Sequential IMA grafting was performed in 5 patients. The sites of IMA grafting were 91 left anterior descending arteries (LAD), 16 diagonal branches, 8 circumflex arteries and 2 right coronary arteries. Saphenous vein or gastroepiploic artery was concomitantly used to bypass the other coronary arteries in 90 patients. The number of distal anastomosis ranged from 1 to 6 and the mean was 2.8 per patient. Two patients died within 30 days and one patient died at 3 months after surgery. Perioperative myocardial infarction was noted in 3 patients. Symptomatic relief was obtained in 94 (97%) of 97 survivors. The patency of the IMA graft at mean 2.2 postoperative months was 97% (58/60) in LAD, 100% (14/14) in the diagonal branch, 100% (5/5) in the circumflex artery, 100% (1/1) in the right coronary artery, and 98% (78/80) in over-all grafted coronary arteries. Pre- and postoperative exercise thallium scintigraphy in 13 patients, who received the IMA graft to severely stenosed LAD, showed significant improvement of the washout ratio (from 33.1 +/- 16.9% to 47.4 +/- 14.8%) which was nearly equivalent to that of the saphenous vein graft to LAD (from 24.8 +/- 6.2% to 48.1 +/- 6.6%, n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Short- and medium-term study of arterial grafts and native coronary circulation after in situ implant of the internal mammary artery

The internal mammary artery (IMA) is being increasingly utilized as a conduit for myocardial revascularization, based on its higher long-term patency. The aim of this study is the serial assessment of the changes of native coronary vessels after IMA coronary anastomosis. Twenty-six consecutive patients (24 males and 2 females, mean age 56.4 years) received an IMA graft on the left anterior descending (LAD) artery. IMA coronary anastomosis was single in 11 patients and double (LAD and diagonal branch) in the remaining 15 cases. In 23 patients (88.5%) at least one associated saphenous vein graft was inserted. Post-operatively, no new Q waves or low-output syndromes were observed. Follow-up angiographic study, including selective opacification of the IMA graft, was carried out after 1 month and after 1 year. The cumulative patency rate of IMA grafts was 97.7% after 1 month. The LAD stenosis proximal to the IMA anastomosis progressed to total occlusion in 6 patients (28.5%), all of them with a preoperative stenosis ranging from 90 to 99%; its diameter remained unchanged in 6 patients (28.5%), while a reduction of the coronary narrowing greater than or equal to 20% was observed in 9 patients (43%). Preoperatively, the LAD stenosis of the latter groups ranged from 70 to 90%. Severity of residual stenosis and relative diameters of LAD artery and IMA graft influenced the competitive flow distribution through these vessels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive detection of total occlusion of the left anterior descending coronary artery with transthoracic Doppler echocardiography.

OBJECTIVES: The purpose of this study was to evaluate the value of transthoracic Doppler echocardiography (TTDE) for the noninvasive detection of total left anterior descending coronary artery (LAD) occlusion. BACKGROUND: Total coronary occlusion is associated with an adverse long-term prognosis, and mechanical revascularization may be required for the patient with total coronary occlusion. However, a noninvasive diagnosis of total coronary occlusion before coronary angiography (CAG) has been difficult, especially in patients without clinical signs. METHODS: We studied 103 consecutive patients who underwent CAG for the evaluation of coronary artery disease. The study group consisted of 16 patients with total LAD occlusion (group A) and 87 patients without total LAD occlusion (group B). Coronary flow velocity in the mid-portion of the LAD was recorded by TTDE. RESULTS: Adequate spectral Doppler recordings of diastolic flow in the LAD were obtained in 98 study patients (95%; 15 patients in group A and 83 patients in group B). In group A, retrograde LAD flow was obtained in 14 (93%) of 15 patients. The mean diastolic velocity of the retrograde flow was 21.0 +/- 6.1 cm/s. In group B, antegrade LAD flow was obtained in all 83 patients (100%). The mean diastolic velocity of the antegrade flow was 21.5 +/- 7.1 cm/s. Retrograde LAD flow by TTDE had a sensitivity of 93% and a specificity of 100% for the detection of total LAD occlusion. CONCLUSIONS: Retrograde flow in the LAD by TTDE is a highly sensitive and specific finding that can be used to noninvasively diagnose total LAD occlusion.     

The efficacy of intermittent coronary sinus occlusion in the absence of coronary artery collaterals

The purpose of this study was to evaluate the efficacy of time-controlled intermittent coronary sinus occlusion (ICSO) in preserving regional and global mechanical function during acute ischemia in an animal preparation without significant arterial collateral vessels. Seventeen (eight control, nine ICSO) swine heart preparations undergoing extracorporeal coronary perfusion in situ were subjected to ligation of the left anterior descending coronary artery (LAD) distal to the first major diagonal branch. Data were obtained before and immediately after coronary artery ligation in both animal groups. ICSO, 15 sec of occlusion alternating with 5 sec of release, was then begun in the treatment group. Additional data were obtained in both control and treatment groups at 15 min intervals for 1 hr starting immediately after coronary artery ligation. Global left ventricular function was assessed by shifts in left ventricular end-diastolic pressure and left ventricular dP/dt with left ventricular systolic pressure maintained at about 100 mm Hg. Regional mechanical function was evaluated with transmurally placed ultrasonic crystals. Pressure was also measured directly in the coronary sinus and LAD distal to the ligature. Regional myocardial blood flow was measured in the ischemic bed using 9 micron diameter radiolabeled microspheres injected before, immediately after, and 60 min after coronary artery ligation in both treated and control animals. LAD mean pressure measured distal to the ligation (less than 16 mm Hg) and ischemic bed myocardial blood flow (less than 0.01 ml/g/min) confirmed the absence of significant arterial-arterial collaterals in this preparation. Mean coronary sinus pressure increased significantly (p less than .001) in treated animals during ICSO (e.g., 11.2 +/- 1.6 to 66.2 +/- 10.0 mm Hg at 15 min after coronary ligation). Mean LAD pressure distal to the coronary ligature also increased during ICSO (14.2 +/- 1.2 to 26.8 +/- 1.6 mm Hg), with a similar but delayed rate of pressure rise. No significant differences in left ventricular end-diastolic pressure or left ventricular dP/dt were noted between control or treated animals after coronary ligation. Ischemic bed systolic wall thickening, present before coronary ligation, was not present after occlusion and was not improved during intermittent coronary sinus occlusion in the treatment group. We conclude that in an animal preparation without significant collateral circulation, intermittent coronary sinus occlusion is incapable of restoring regional or global left ventricular mechanical function during conditions of acute ischemia.     

Detection of patency of internal mammary artery grafts to the left anterior descending artery by transthoracic Doppler echocardiography

BACKGROUND: To determine whether a coronary artery bypass graft (CABG) is patent, we examined the flow of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) by transthoracic Doppler echocardiography (TTDE). PATIENTS AND METHODS: Eighty-seven patients with CABG (LIMA to distal LAD) were enrolled in the study. The flows from each subject were analyzed by three criteria: mosaic flow at the anastomosis site, distal anterograde flow (ante flow), and proximal retrograde flow (retro flow). RESULTS: On angiography, 79 grafts were patent and eight were not. TTDE study of 79 patent grafts demonstrated mosaic, ante, and retro flow in 63 (79.7%), 74 (93.7%), and 35 grafts (49.4%), respectively. The averaged diastolic peak velocity of ante flow was 26.3 +/- 11.0 cm/sec, significantly higher than that (4.8 +/- 7.1 cm/sec, P < or = 0.0001) in eight patients without patent grafts. These eight patients had no mosaic or retro flow and only three had ante flow. The accuracies to predict patency were 81.6%, 90.8%, and 49.4% for mosaic, ante, and retro flows, respectively. CONCLUSIONS: The existence of mosaic, retro, or sufficient ante flows strongly indicated the patency of LIMA to the LAD. When symptoms are possible to be derived from the occlusion of CABG to LAD, TTDE is a promising method to examine whether a LIMA to LAD bypass is patent.     

Catheter-based ventricle-coronary vein bypass.

The goal of this study was to investigate the feasibility of a catheter-based ventricle-to-coronary vein bypass (VPASS) in order to achieve retrograde myocardial perfusion by a conduit (VSTENT) from the left ventricle (LV) to the anterior interventricular vein (AIV). Percutaneous coronary venous arterialization has been proposed as a potential treatment strategy for otherwise untreatable coronary artery disease. In an acute setting, the VSTENT implant was deployed percutaneously using the VPASS procedure in five swine. Coronary venous flow and pressure patterns were measured before and after VSTENT implant deployment with and without AIV and left anterior descending artery (LAD) occlusion. In a separate chronic pilot study, the VPASS procedure was completed on two animals that had a mid-LAD occlusion or LAD stenosis. At day 30 post-VPASS procedure, left ventriculography and magnetic resonance imaging (MRI) were performed to assess the patency and myocardial viability of the VSTENT implants. Pre-VSTENT implantation, the mid-AIV systolic wedge pressure was significantly lower than LV systolic pressure during AIV blockage (46 +/- 19 vs. 90 +/- 16 mm Hg; P < 0.01). The VSTENT implant deployment was performed without complication and achieved equalization of the AIV and LV systolic pressures and creation of retrograde flow in the distal AIV (maximal flow velocity: 37 +/- 7 cm/sec). At day 30 post-VPASS procedure, left ventriculography showed VSTENT implant patency. MRI perfusion images demonstrated myocardial viability even with an LAD occlusion. Coronary retrograde perfusion using the VPASS procedure is feasible and may represent a potential technique for end-stage myocardial ischemia.     

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)     

Occlusion of a giant saphenous vein graft aneurysm using distal coil embolisation and a proximal vascular plug

An asymptomatic giant true saphenous vein graft aneurysm was successfully occluded by percutaneous distal coil embolisation combined with deployment of a proximal Amplatzer vascular occlusion plug. The aneurysm cavity was excluded from both antegrade flow via the aortosaphenous anastamosis and retrograde flow via the distal left anterior descending coronary artery (supplied by a left internal mammary artery graft), to reduce the risk of subsequent aneurysm rupture.     

Do changes in blood flow in the subclavian artery affect flow volume in IMA grafts after complete arterial revascularization with the T-graft technique?

BACKGROUND: The T-graft procedure achieves complete arterial coronary revascularization with only two conduits. In this technique, all the bypass anastomoses are supplied by the left internal mammary artery (IMA). Changes in flow conditions or flow redistribution in the subclavian artery may thus sigificantly influence coronary perfusion. The objective of this study was to determine whether changes in blood flow in the subclavian artery affect the flow in IMA grafts in patients who have undergone complete arterial revascularization with T-grafts. METHODS: Quantitative flow volume and flow profiles in the IMA graft and the proximal subclavian artery were measured with a flow-wire in 20 patients one week postoperatively. Following baseline measurements, brachial artery constriction was achieved by applying a blood pressure measurement cuff to the patient's left upper arm. After 5 minutes, quantitative flow in the IMA and in the proximal subclavian artery was assessed. The cuff was then released and the measurements repeated. RESULTS: Flow in the subclavian artery changed significantly (p < 0.01) from baseline (355.4 +/- 95.2 ml/ min) to constriction (171.2 +/- 61.3 ml/min) and hyperemia (679.3 +/- 195.1 ml/min). Flow in the IMA graft remained constant irrespective of subclavian artery flow (75.4 +/- 26.2 ml/min vs. 78.0 +/- 28.9 ml/min vs. 75.5 +/- 29.3 ml/min, respectively). The flow profile in the IMA was similarily unchanged. CONCLUSION: In patients in whom the coronary bypass blood flow is dependent on the left IMA, neither the quantitative flow volume nor the flow profile are altered by changes in blood flow of the subclavian artery.     

Intraoperative Flu?messung koronarer Bypassgef??e mit der Ultraschall-Transit-Zeit-Methode

The aim of the study was to compare the mean and maximum flow and the flow pattern of coronary vein grafts (SVG) supplying target vessels of the inferior and lateral wall with internal mammary (IMA) grafts to the left anterior descending artery (LAD). In 21 patients 25 bypass grafts (13/25 SVG, 12/25 IMA) were investigated. Using the transit time ultrasound method, flow was measured every 5 ms and the flow data of 60 s were acquired. The flow pattern showed significant differences between both graft types during their cycle. IMA grafts showed only one peak occurring after 22.1+/-12.3% and the second after 63.4+/-15.5% of their cycle. The mean flow was not different in both graft types (IMA: 45.3+/-27.0 ml/min and SVG: 41.8+/-26.7 ml/min, p = n. s.) as it was the case for the maximum flow (IMS: 98. 4+/-45.2 ml/min and SVG: 75.7+/-55.4 ml/min, p = n. s.). In conclusion, there is a different flow pattern for both graft types concerning the number and the occurrence of flow-peaks in the bypass cycle. The mean and peak flow showed no significant difference.     

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.     

SequentiaI RevascuIarization of Intramuscular Left Anterior Descending Coronary Artery

A bstract We present a new technique for avoiding possible kinking or angulation of the sequential left internal mammary artery to left anterior descending artery (LIMA-LAD) anastomoses when the LAD follows an intramuscular course. A 3- to 5-mm cusp of saphenous vein segment is interposed between the intramuscular LAD segment and internal mammary artery (IMA) at the sequential anastomotic site, to which the distal portion of the IMA was anastomosed in standard end-to-side fashion.     

Atresia of the left internal mammary artery graft following percutaneous intervention of the left main

Because of its durability and patency, the left internal mammary artery (LIMA) is preferentially used to bypass obstructive lesions in the left main coronary artery (LMCA) and/or the left anterior descending coronary artery (LAD). The long-term patency of the LIMA graft is determined by several factors, principal among them being the dynamic competition between flow through the internal mammary artery graft and the LAD. We report a patient with LMCA stenosis and a well-functioning and mature LIMA graft, who after percutaneous intervention of the LMCA and normalized antegrade flow in the LAD, developed atresia of a large caliber LIMA graft.     

Internal mammary artery steal syndrome secondary to a para-IMA after coronary artery bypass graft： a case report

Introduction
The use of the intemal mammary artery （IMA） in coronary artery bypass graft（CABG） for myocardial revascularization is gaining popularity in routine practice, especially when the target vessel is the left anterior descending artery （LAD）. Occasionally, IMA hypoperfusion occurs when there is inadequate flow through the IMA graft to the LAD artery due to the exist of lateral branches.     

Challenges associated with treatment of left internal mammary artery graft thrombosis

Acute occlusion of the left internal mammary artery (LIMA) graft late after coronary artery bypass grafting surgery is a rare and potentially life‐threatening complication. We describe a case of acute myocardial infarction 19 years after coronary artery bypass graft surgery due to acute occlusion of the distal anastomosis of a LIMA graft to the left anterior descending artery. Aspiration thrombectomy failed to remove the thrombus. Laser thrombectomy caused perforation. After drug‐eluting and covered stent implantation, antegrade TIMI 3 flow was restored with an uneventful postprocedural course.