Value of reversed saphenous vein in minimally invasive direct coronary artery bypass graft procedures

BACKGROUND: Minimally invasive direct coronary artery bypass graft procedures are gaining acceptance for revision as well as primary coronary revascularization. When suitable, the left and right internal mammary arteries are preferred as bypass conduits; in other cases, the greater saphenous vein, used for standard coronary artery bypass graft procedures, may be useful to revascularize coronary artery branches during minimally invasive direct coronary artery bypass graft procedures. METHODS: We used the greater saphenous vein on three occasions during minimally invasive direct coronary artery bypass graft procedures (1) to revascularize the left anterior descending coronary artery by anastomosis to the left axillary artery in the infraclavicular region, (2) as an extension to the left internal mammary artery to reach the left anterior descending coronary artery, and (3) as a bridge from the splenic artery to bypass the distal right coronary artery. RESULTS: Postoperatively, all 3 patients had relief from symptoms of coronary artery insufficiency and none has been readmitted to the hospital with symptoms. Angiography or thallium studies were not performed to confirm graft patency because all patients were elderly and the risks of these procedures were considered to outweigh their potential benefit. CONCLUSIONS: The greater saphenous vein is a potential bypass conduit for use in minimally invasive direct coronary artery bypass graft procedures as well as for coronary artery bypass graft procedures.     

Ultrasonographic evaluation of the anterior recess in the normal hip: a prospective study on 166 asymptomatic children

Bypass graft patency with ultrafast computed tomography (= Electron Beam Tomography, EBT) was examined in 72 bypass grafts (47 saphenous veins, 25 internal mammary arteries) in 30 patients and compared with coronary angiography. Angiography was performed a mean of 4.4 +/- 3.5 months (range 1-13) from the EBT examination. Contrast material (120 ml) was continuously administered via a peripheral vein and 40 axial slices (3 mm slice thickness, 110 ms scan time) without overlap sequences were obtained, ECG triggered with the single slice scanner mode. Imaging of internal mammary artery grafts began at the thoracic inlet, for saphenous vein grafts, at the undersurface of the aorta. Sixty of 63 angiographically patent bypass grafts were determined patent by EBT (sensitivity 95%), 8 bypass grafts could not be detected by EBT, and 9 were angiographically occluded (specificity 89%). Twenty-four of 25 internal mammary artery grafts were patent at EBT and coronary angiography, one was occluded. In 27 of the 30 patients (90%), all of the angiographically patent grafts could be confirmed as open with EBT. Obstructions of 10 grafts could not be visualized with EBT. Graft insertion into native coronary vessels could be visualized in axial slices, although morphologic quantification of graft insertion stenosis (75-90%) in two cases was not possible. Three dimensional reconstruction of the 40 axial slices allowed graft anatomy to be delineated. Visualization of bypass insertion into the native coronary vessel was less successful because of opacification of the left and right ventricle. Electron beam computed tomography is a minimally invasive procedure capable of evaluating the patency of saphenous vein and internal mammary artery grafts. The morphologic quantification of graft obstruction and visualization of the insertion of the bypasses into the native coronary vessels is less successful with present technology and imaging modalities.     

Cardiac revascularization using both mammary arteries

Both internal mammary arteries in combination with veins were used for revascularization of the hearth in fifty Danish patients undergoing coronary artery bypass grafting (CABG) at Gentofte Hospital during the period 1994-1996. Patients with insulin-dependent diabetes mellitus, obesity, and age over 75 years were excluded. The patients were followed for at least one month after the operation. No patients died, and the complication rate was low and comparable to standard CABG using the left mammary artery and vein grafts. It is known from the literature that 10 years after CABG only 50% of vein grafts remain patent, and half of these have severe atherosclerosis. The mammary artery is far more resistant to atherosclerosis and 15 years after the procedure fewer patients have recurrent angina when both mammary arteries have been used. Bilateral mammary artery grafts can be used in half of CABG-procedures, and are especially indicated in younger patients.     

Reoperative coronary bypass grafting without cardiopulmonary bypass through a small thoracotomy

BACKGROUND: The danger of coronary reoperations is mainly hidden in the reopening of the sternum and in the manipulation of the heart and the old grafts. Therefore, the minimally invasive direct coronary artery bypass procedure seems an ideal technique for coronary reoperations if only the left anterior descending coronary artery needs to be revascularized and the left internal mammary artery has not been used previously. METHOD: From January 1995 until May 1996 we performed 81 minimally invasive direct coronary artery bypass procedures through a small anterolateral thoracotomy in the fifth intercostal space, anastomosing the left internal mammary artery to the left anterior descending coronary artery. Six of these 81 were reoperative minimally invasive direct coronary artery bypass procedures on patients who had previously undergone coronary grafting through a median sternotomy with a vein graft to the left anterior descending coronary artery. RESULTS: Mean operation time was 85.8 +/- 22.2 minutes. Mean length of the mammary pedicles was 13 +/- 2 cm. Mean coronary occlusion time was 9.2 +/- 3.2 minutes. Mean postoperative hospital stay was 5.7 +/- 1.2 days (range, 5 to 8 days). No mortality and no cardiac-related morbidity were recorded. CONCLUSIONS: These results suggest that the technique is safe and promising in selected cases of reoperative coronary operation.     

Coronary steal through anomalous internal mammary artery graft. Treated by ligation without sternotomy

A patient who had undergone adequate coronary revascularization with a left internal mammary artery graft to the left anterior descending coronary artery and with saphenous vein grafts to the right coronary artery and to the 1st and 2nd obtuse marginal branches presented with early-onset recurrent angina. A repeat angiogram showed an abnormally large branch arising from the very proximal segment of the left internal mammary artery and supplying the whole lateral chest wall via many intercostal tributaries. Relief of symptoms was achieved by ligation of this branch, and the patient remains symptom free more than 6 years after the procedure.     

Anatomic variability of rejection in intestinal allografts after pediatric intestinal transplantation

The internal mammary artery is routinely used for coronary artery bypass grafting because of its optimal long-term patency profile. This vessel can be imaged by angiography, but only the proximal tract at the origin from the succlavian artery can be imaged by conventional echography. The aim of our study was to visualize the intrathoracic course of the native and grafted internal mammary arteries by a new ultrasound equipment which allows high-resolution transthoracic color Doppler imaging of the chest wall vessels and coronary arteries. We studied 35 patients, 16 non operated and 19 operated of coronary surgery with the internal mammary artery grafted to the left anterior descending coronary artery. We used a multifrequency 3.5-7 MHz transducer with a small insonating surface, placed at the second-fifth intercostal space at the left and right sternal border, to image the native mammary arteries. The grafted mammary artery was detected at the fourth-fifth left intercostal space 2-4 cm lateral to the sternal border. The native left internal mammary artery was visualized in all 16 non operated patients, and the right internal mammary artery in 14/16 (87%). The native left internal mammary artery peak flow velocity was 41-160 cm/s (mean 81 +/- 34 cm/s), and the mean flow velocity was 28-89 cm/s (mean 45 +/- 17 cm/s). The right internal mammary artery peak flow velocity was 35-153 cm/s (mean 82 +/- 36 cm/s), and mean flow velocity was 21-82 cm/s (mean 46 +/- 22 cm/s). The grafted left internal mammary artery was visualized in 16/19 patients (84%), evaluated at 6 days to 36 months after surgery. Peak diastolic flow velocity ranged from 24 to 80 cm/s (mean 48 +/- 17 cm/s), and mean diastolic flow velocity ranged from 13 to 57 cm/s (mean 33 +/- 11 cm/s). The left anterior descending peak flow velocity distal to the anastomosis was 22-62 cm/s (mean 37 +/- 15 cm/s) and mean flow velocity was 18-53 cm/s (mean 29 +/- 12 cm/s). We conclude that transthoracic color Doppler echocardiography allows to image the native and grafted mammary arteries, with potential clinical applications in the management of patients with coronary artery disease.     

Experience with internal mammary artery grafts in 298 patients

The internal mammary artery (IMA) was used as a graft in 298 patients undergoing coronary bypass procedures. Two patients died during the operative period and 2 others died one year later. Most of the survivors are free of angina. Of the IMAs restudied 9 to 24 months postoperatively, 95% were patent. This group included nearly all the patients having angina after operation. There are some situations in which the IMA may have inadequate flow in comparison to the vein graft. These results suggest the IMA is an excellent graft in most coronary bypass procedures.     

New stent technologies

Poor long-term patency of saphenous vein grafts limits the long-term success of the coronary artery bypass operation. If this is to be improved, either measures that increase the patency of saphenous vein grafts or alternative conduits are required. The benefits of using the left internal mammary artery as a pedicled graft to the left anterior descending coronary artery have prompted increasing use of arterial grafts to further improve outcome. Concurrently advances in the understanding of the pathological processes underlying saphenous vein graft occlusion raise the possibility of improving vein graft patency. In this paper we review the problem of vein graft occlusion and possible solutions, the theoretical benefits of arterial grafts and the clinical results associated with their use.     

Minimally invasive surgery for coronary disease: a new alternative

To avoid the inflammatory syndrome generated by cardiopulmonary bypass, a new surgical technique, minimal invasive direct coronary artery bypass (MIDCAB), has been developed. An anastomosis is performed between the left internal mammary artery (LIMA) and the left anterior descending artery (LAD) on a beating heart, through a limited anterior thoracotomy. We describe our experience with this technique. Ten consecutive patients underwent a MIDCAB procedure. (9 males, age 65.9 +/- 9 years). There were 8 bypasses of the LIMA on the LAD, one bilateral mammary bypass on the LAD and the right coronary artery, and one conversion to a standard sternotomy with CPB for a saphenous vein bypass on the LAD because of injury to the LIMA (2nd case). There was one redo for haemostasis of the mammary artery bed (3rd case). The first 3 patients required postoperative blood transfusion. From the 4th operation onwards, with the introduction of new instrumentation which was better adapted to the narrowness of the surgical field, there were no further surgical complications. During the follow-up (mean 5 months; range 2-9), no patient suffered anginal recurrence. With the improvement of instrumentation, the MIDCAB technique offers satisfactory short- and mid-term results, while avoiding CPB with its adverse effects. Lastly, the cosmetic result is far better than with the conventional procedure.     

Use of the polymerase chain reaction in the diagnosis of leprosy

A case is described in which a pericardial branch of a nongrafted left internal mammary artery communicated directly with the distal left anterior descending artery, following saphenous vein bypass grafting. This type of collateralization following coronary artery bypass surgery seems to be very rare, and perhaps could protect the myocardium from severe ischemia.     

Complete direct mammary harvest for minimally invasive coronary artery bypass

Minimally invasive coronary artery bypass has primarily involved left internal mammary artery grafting to the left anterior descending coronary artery through a small left anterior thoracotomy incision. Harvesting of the mammary artery has been accomplished completely using a video-assisted thoracoscopic technique or incompletely to the second interspace under direct vision. With a mammary retractor, the mammary artery can be dissected completely under direct vision, thus eliminating any criticism of an incomplete harvest and any increased difficulty or expense associated with the thoracoscopic harvest. In this series, all 17 mammary arteries were successfully harvested completely under direct vision and 16 patients underwent successful minimally invasive coronary bypass.     

Minimally invasive coronary artery bypass grafting: port-access approach versus off-pump techniques

BACKGROUND: Within the past 5 years several surgical techniques have been developed for less invasive surgical treatment of coronary artery disease. The aim of this study was to define specific indications for the various minimally invasive coronary artery surgical procedures. METHODS: Minimally invasive direct coronary artery bypass grafting through a minithoracotomy was performed in 67 patients. The left internal mammary artery was anastomosed on the beating heart with the use of a pressure or suction stabilizer without the use of extracorporeal circulation. In 58 other patients with multivessel disease, the off-pump coronary artery bypass grafting technique through a sternotomy was applied with a left internal mammary artery to left anterior descending artery and additional vein grafts without extracorporeal circulation. In a third group, Port-Access (Heartport Inc, Redwood City, CA) coronary artery bypass grafting was performed through a left minithoracotomy with the use of an endovascular extracorporeal circulation system and cardioplegic arrest. Angiographic follow-up was complete in 64% of the patients. RESULTS: There was minimal perioperative or postoperative mortality (0.5%). The medium surgical procedure time for all minimally invasive and off-pump procedures was 2.5 hours; it was 4.5 hours for Port-Access procedures. The median postoperative intensive care unit stay was 1.0 days, and the median hospitalization was 5.0 days. Overall graft patency was 97.3%; in 8 patients (4.1%) a stenosis either at or distal to the graft anastomosis was dilated with coronary angioplasty. CONCLUSIONS: For single-vessel disease of the left anterior descending artery, the minimally invasive coronary artery bypass grafting procedure can be performed safely without the use of extracorporeal circulation. In case of hemodynamic instability or anatomic variation, the Port-Access procedure can be applied without additional necessity for sternotomy. For multivessel disease, the off-pump bypass grafting procedure with sternotomy can be recommended depending on the coronary arteries involved. In case of necessary grafts to the lateral marginal or circumflex branches, Port-Access grafting can be recommended and may play an important role in the future for the development of fully endoscopic robot-assisted coronary artery bypass grafting.     

Coronary revascularization and abdominal aortic aneurysm repair in a patient with Beh?et's diseases

Beh?et's disease is a systemic disease characterized by oral aphta, genital ulcer, and ocular lesion. Arterial involvement is an uncommon complication of Beh?et's disease, and it most frequently affects the abdominal aorta followed by the femoral artery and the pulmonary artery. Coronary lesions in Beh?et's disease have been little reported in the literature. In this communication, we present a case with coronary artery stenosis and with subsequently developed supra-renal abdominal aortic aneurysm. The coronary lesions were revasculized with gastroepiploic artery, right internal mammary artery, and saphenous vein graft. Abdominal aortic repair was performed with partial cardiopulmonary stand by, because of the risk of coronary ischemia during the cross clamp including the celiac artery. To our knowledge, this is the first report of successful repair of combined lesions of the coronary and the abdominal aorta in a patient with Beh?et's disease.     

Bilateral internal mammary artery atherosclerosis: a late complication of delayed repair of coarctation of the aorta

A 58-year old patient who had undergone repair of aortic coarctation at 19 years of age, subsequently developed coronary artery disease requiring coronary artery bypass surgery. At operation both internal mammary arteries were found to be totally occluded with calcific atherosclerosis. We therefore advise that the internal mammary arteries should be assessed carefully in patients with similar past histories.     

Oropharyngeal synovial sarcoma. Report of one case]

OBJECTIVE: To assess the prognostic factors of myocardial recovery expected after coronary bypass surgery and the impact of surgical technique used, a prospective non-randomized study including a 1-year postoperative evaluation of left ventricular function was performed in patients with left ventricular dysfunction (left ventricular ejection fraction (LVEF) < 0.40). METHODS: From 1993 to 1996, 110 patients (mean age 61+/-11 years) were included in the study. The mean LVEF was 31+/-6%. All patients had preoperative radionuclide investigations based on the combination of stress/reinjection thallium single photon emission computed tomography (SPECT) and planar evaluation of LVEF; 88% of patients had reversible ischemic thallium defects. Two surgical technique were used: 53 patients received the left internal mammary artery with associated sequential vein graft, and 57 patients received only arterial grafts, internal mammary and gastroepiploic arteries. The mean number of distal anastomoses was 3.2+/-0.8 and 54% of patients had complete revascularization. At 1 year, all survivors had clinical evaluation and the same radionuclide investigations. RESULTS: The early mortality was 2.7%. At 1 year, 100 patients were surviving; on average, NYHA class decreased 1.9+/-0.8 to 1.4+/-0.6 (P < 0.01) and CCS class from 2.8+/-0.6 to 1+/-0.3 (P < 0.01). The mean LVEF increase from 31+/-9 to 34+/-10% (P < 0.01) and the mean LV end-diastolic volume decreased from 317+/-112 to 285+/-108 ml (n.s.). The postoperative improvement in LV function was higher in patients in NYHA class 3 or 4 before surgery (P < 0.05), when associated sequential vein graft had been used (P < 0.01), and in patients with low preoperative LVEF (P < 0.01). The postoperative LVEF improvement observed was significantly correlated with the improvement in left ventricular end-diastolic (LVED) volume and the improvement in redistribution/reinjection thallium uptake. Multivariate analysis showed that the surgical technique used and the preoperative LVEF were independent prognostic factors of the postoperative myocardial function recovery, with a significant positive impact of the vein use. CONCLUSION: This study confirms the excellent clinical results of coronary artery bypass grafting (CABG) in patients with coronary artery disease and LV dysfunction; improvement in LV function can be documented objectively and is correlated with reperfusion of hibernating myocardium. However, the extended use of arterial grafts does not allow to achieve the significant myocardial recovery observed with the use of one internal mammary artery (IMA) and associated sequential vein graft; it seems to be related to the preoperative selection of patients, but a direct negative impact of arterial grafts was documented and leads to be cautious in patients with severe LV dysfunction.     

Two repressor elements inhibit expression of the von Willebrand factor gene promoter in vitro

The objective of this study was to examine the endothelial function of internal mammary artery in patients with coronary artery disease and in heart transplant recipients. Therefore the response of this artery to increasing concentrations of acetylcholine (1, 10, 20 microg/min for 2.5 minutes each) was assessed in 6 patients in a control group, 16 patients with coronary artery disease (CAD group) matched for risk factors with 16 heart graft recipients (who underwent transplantation for nonischemic heart failure), and 12 patients with coronary artery disease and peripheral vascular disease (PVD group). Diameters of proximal and middle segments of internal mammary artery were measured by quantitative angiography. The responses to the first concentration of acetylcholine were attenuated in these three groups compared with the control group. At the highest concentration of acetylcholine the diameter increase was similar in the control and CAD groups, whereas the responses remained significantly impaired in the transplant and PVD groups. However, after selective infusion of L-arginine (30 mg/min for 11 minutes), the precursor of endothelium-derived nitric oxide, was performed, the responses to acetylcholine were restored in these two latter groups. Endothelin plasma levels were significantly enhanced in the PVD group, which exhibited the most severe impairment in acetylcholine-induced vasodilation. Thus some patients with CAD, mainly those with advanced atherosclerosis, and cardiac transplant recipients exhibit internal mammary artery endothelial dysfunction, and this abnormality seems reversible.     

Angina caused by subclavian-coronary steal in patients revascularized with internal mammary artery]

After coronary bypass surgery in the left internal mammary artery, occlusive atherosclerosis in the proximal subclavian artery can produce reverse flow in the mammary artery and myocardial ischemia (coronary-subclavian steal syndrome). This is a rare cause of recurrent myocardial ischemia. We present two patients with postoperative complete obstruction in the proximal subclavian artery and inverse flow in the mammary artery producing severe ischemia in the left anterior descending artery territory. Both patients were treated with subclavian-subclavian bypass, which in one patient was ineffective in producing an adequate anterograde flow in the left internal mammary artery. We review clinical management, diagnostic methods and therapeutic options used in the coronary-subclavian steal syndrome.     

Morphological and angiographic studies on mammary artery in coronary sclerosis

Macroscopic and microscopic studies on the anterior interventricular ramus of left coronary artery, internal thoracic artery, and great saphenous vein were carried out 50 dead, aged 21 to 60 years. The internal thoracic artery was always normal whereas in 40 cases stenosing coronary sclerosis was found. At mammography, 25 patients with operable coronary obstruction also showed no degenerative alterations of this systematic artery. With a diameter of 1.5 mm in the 5th intercostal space the internal thoracic artery was fit for performing an anastomosis.     

Vasodilatory effects of adenosine A2 receptor agonists CGS 21680 and CGS 22492 in human vasculature

The vasodilatory effects of the adenosine analogs, 5'-N-ethylcarboxamidoadenosine (NECA), 2-[p-(2-carboxyethyl)phenethyl amino]-5'-N-ethylcarboxamidoadenosine (CGS 21680) and 2-[(2-cyclohexylethyl)amino]adenosine (CGS 22492) in human coronary, internal mammary artery and saphenous vein were examined in vitro. All produced concentration-dependent relaxations in arterial as well as venous rings contracted with 35 mM KCl. The concentration-response curves for NECA and CGS 21680 were parallel in the coronary. The adenosine A2 receptor antagonist, 9-chloro-2-(2-furyl)[1,2,4]triazolo[1,5-c]quinazolin-5-amine (CGS 15943A) significantly attenuated the relaxing response to the adenosine analogs in coronary artery. Although NECA and CGS 22492 were equally as effective at the highest concentration administered (both achieving approximately 70% relaxation at 10(-4) M) NECA (EC50 = 1.25 +/- 0.11 microM) induced greater vasodilation at lower concentrations than CGS 22492 (EC50 = 11.27 +/- 1.53 microM). CGS 21680 was the least potent of the agents tested achieving only 44% relaxation at 10(-4) M (EC50 = 4.71 +/- 0.46 microM). Coronary artery appeared to be more responsive than internal mammary artery or saphenous vein which displayed only marginal relaxation to these agents.     

Study of the coronary flow with high resolution transthoracic echocardiography and nondirectional Doppler

Two-dimensional echocardiography allows to evaluate the effect of myocardial ischemia on left ventricular wall motion, but a direct measure of coronary flow by this method is still lacking. The aim of the present study was to evaluate the efficacy of a new, high-resolution echocardiographic equipment designed to image the epicardial and intramural coronary vessels by non directional Doppler. We studied 33 consecutive patients by transthoracic echocardiography in apical projections, to detect one or more segments of the left anterior descending coronary artery by non directional Doppler. Once the coronary artery has been imaged, pulsed Doppler was used to measure coronary blood flow velocity at rest. Peak and mean flow velocities were measured on the diastolic phase of the Doppler spectrum. In 25/33 patients (75.7%) the middle-distal tract of the left anterior descending coronary artery was imaged by non directional Doppler. In 15/33 patients (45.5%) the periapical tract of the left anterior descending coronary artery was imaged along with its perforating branches. In 2 out of 4 patients operated of coronary artery bypass grafting, the anastomosis between the left internal mammary artery and the left anterior descending coronary artery was imaged. In all 25 patients it was possible to measure by pulsed Doppler the coronary velocity flow pattern, characterized by a typical prevalent diastolic component. Peak diastolic flow velocity was 49.98 +/- 17.30 cm/s and mean diastolic flow velocity was 36.52 +/- 11.91 cm/s. The Doppler pattern of the grafted mammary artery was different from the native mammary flow. This new non invasive imaging technique of the coronary arteries promises to expand the field of diagnostic and experimental echocardiography and brings new insight into the pathophysiology of ischemic heart disease.