A novel approach to coronary revascularization in patients with severely diseased aorta.

Atheromatous disease of the aorta significantly increases morbidity and mortality during coronary revascularization. The surgical approach must be modified for patients in whom this condition is identified. In this report, we describe a technique that uses bilateral internal thoracic arteries as composite grafts with reverse saphenous veins. The operation is performed without cardiopulmonary bypass. We report the cases of 2 patients who underwent this procedure. Neither patient experienced signs or symptoms of atheromatous embolization, and there was no perioperative morbidity or mortality. Off-pump myocardial revascularization using bilateral internal thoracic arteries is an attractive surgical approach for patients who have atheromatous aortas or other conditions in which it is advantageous to avoid aortic manipulation, cannulation, cross-clamping, and cardiopulmonary bypass.

Occlusion of left coronary artery ostium by an aortic valve cusp.

Congenital anomalies of the aortic valve can be associated with other cardiac anomalies. In this report, we present a patient with an aortic valve anomaly associated with occlusion of left coronary ostia. In addition, we reviewed the literature and found 10 similar cases. Although compatible with life, this anomaly can lead to significant symptoms. Preoperative diagnosis as well as proper therapeutic planning should be tailored to correct valvular competence and restore coronary blood flow.

Giant aneurysm of saphenous vein graft to coronary artery compressing the right atrium.

Aneurysm of reverse aortocoronary saphenous vein graft is a known complication of coronary artery bypass grafting. In this report we present a case of a 60-year-old man who presented 12 years after coronary artery bypass grafting with a giant graft aneurysm of the reverse aortocoronary saphenous vein graft to the right coronary artery, compressing the right atrium. Spiral computed tomography was used to identify the aneurysm measuring 7 x 6 x 7 cm. We also reviewed the English-language literature and found reports of 50 patients with similar aneurysms of which 30 (61%) were identified as true aneurysms and 17 (33%) were identified as pseudoaneurysms. Three patients could not be identified into either group. We reviewed the presenting symptoms, diagnostic tools, and treatment options for this rare entity. An understanding of the pathophysiology of reverse aortocoronary saphenous vein graft aneurysm is important to prevent the possibility of aneurysm rupture, embolization, myocardial infarction, or death.

Routine myocardial revascularization with the radial artery: a multicenter experience.

BACKGROUND: Current literature documents use of the radial artery (RA) for myocardial revascularization only as an alternative conduit in cases where the saphenous veins have been previously harvested or are unsuitable for use. Large-scale routine clinical use of the RA as the conduit of choice has not been reported. METHODS: This prospective study evaluated the harvest of the RA from 933 patients and the subsequent use of the conduit as a preferred coronary artery bypass graft second only to the left internal thoracic artery in 930 of these patients. RESULTS: Unilateral RA harvest was performed in 786 patients and 147 patients had bilateral RA harvest. A total of 1080 RAs were harvested; 214 (19.8%) originated from the dominant forearm. There was a mean of 3.30+/-0.93 grafts per patient of which 2.43+/-0.83 were arterial grafts. The mean number of RA grafts was 1.43+/-0.53. Operative mortality was 2.3% with none due to the RA graft(s). There was no ischemia nor motor dysfunction in the operated hands. Thirty-two (3.4%) patients experienced transient thenar dysesthesia that resolved in 1 day to 6 weeks. CONCLUSIONS: Our results demonstrate that routine total or near total arterial myocardial revascularization may be achieved safely and effectively with the use of one or both RAs in conjunction with the internal thoracic artery.

Redox potential measurements of plasma in patients undergoing coronary artery bypass graft and its clinical significance.

The apparent redox potentials (Em) of plasma as a marker of oxidant injury during coronary artery bypass graft (CABG) is determined, and their clinical significance is discussed. We measured plasma Em of normal volunteers (n = 20) and samples drawn at different time points from patients undergoing elective CABG (n = 60) directly and by adding 5 microl (20 mM) oxidants or reductants with known redox potential to plasma (95 microl), using a micro Pt/AgCl combination redox electrode. The Em value stays elevated up to 30 min during the surgery, after the administration of protamine it came down toward a more reduced state. Similar changes are seen with the lactate pyruvate ratio. Smaller changes of Em than normal are observed in plasma samples from patients treated with Aprotinin (antiprotease), Carmeda (heparin-coated) circuit and aspirin reflecting their protective effect. Redox potential (Em) measurements appear to be effective and useful in monitoring redox shifts wherever oxidative stress needs to be monitored.

Surgery for ischemic heart disease.

Surgical treatment for ischemic heart disease continues to evolve. The long-term benefit of coronary artery bypass grafting can be shown to extend for 15 to 20 years. The long-term patency achieved with internal thoracic artery grafts has extended the already good results of coronary artery bypass grafting. It is the surgeon's hope that the pursuit of multiple arterial grafting will further extend these results. Operations continue to increase in complexity and include a growing number of reoperations. Techniques to deal with these situations have continued to evolve so that the operative mortality remains low. The role of angioplasty in patients with multiple-vessel coronary artery disease has not been firmly established. However, increasing data indicate that in patients with triple-vessel disease and depressed ventricular function, complete surgical revascularization is the treatment of choice.

Profound systemic hypothermia protects the spinal cord in a primate model of spinal cord ischemia.

Spinal cord ischemia with resultant paraplegia or paraparesis remains an important clinical problem after operations on the thoracoabdominal aorta. Because hypothermia has a protective effect on ischemic neural tissue, we developed a baboon model of spinal cord ischemia to simulate the situation encountered clinically for resection of aneurysms of the thoracoabdominal aorta and to determine whether profound hypothermia produced by hypothermic cardiopulmonary bypass has a protective effect on spinal cord function. After cardiopulmonary bypass was established, the aorta was clamped distal to the left subclavian artery and proximal to the renal arteries for 60 minutes. Group I animals (n = 9) underwent aortic clamping at normothermia (37 degrees C), and group II animals (n = 9) were cooled to a rectal temperature of 15 degrees C before aortic clamping and underwent cardiopulmonary bypass at this temperature until the aorta was unclamped. Of the eight operative survivors in group I, six animals were paraplegic and two were paraparetic, whereas all six group II animals that survived the procedure were neurologically intact (p = 0.0002). The protective effect of hypothermia was associated with blunting of the hyperemic response of spinal cord blood flow (determined by the radioactive microsphere technique) in the lower thoracic and the lumbar segments of the spinal cord after unclamping of the aorta. Profound hypothermia produced by hypothermic cardiopulmonary bypass may be an effective method of protection of the spinal cord in patients undergoing repair of aneurysms of the thoracoabdominal aorta and may reduce the prevalence of ischemic injury to the spinal cord.

Surgery for ischemic heart disease.

Surgical treatment of ischemic heart disease continues to evolve, and specific criteria are available to guide management. The benefit of placing the left internal mammary artery to the left anterior descending artery is well known, and there are newer data, not including survival benefit, supporting the use of two internal mammary arteries. The role of more than two arterial conduits remains to be established. It is hoped that greater use of arterial conduits will reduce the need for reoperation due to saphenous vein graft closure. Operations on older patients and on those with severe impairment of left ventricular function continue to increase. These cases present an ongoing challenge, as do those when operation for acute failure of angioplasty is required.

A model of right ventricular failure after global myocardial ischemia and mechanical left ventricular support.

Postcardiotomy right ventricular (RV) failure after institution of mechanical left ventricular (LV) support is poorly understood. Using a canine model supported by cardiopulmonary bypass (CPB), the animals underwent 30 min of aortic clamping or no ischemia and were weaned to an LV assist device (LVAD). Echocardiographic measurements of LV and RV cavity size off support allowed calculation of percentage change in cavity area (fractional shortening). There were no differences at baseline. After 2 hrs on LVAD, there were significant differences between ischemic and control groups in both LV (38 +/- 12 vs. 61 +/- 6) and RV (15 +/- 3 vs. 55 +/- 12). The ischemic RV also had significantly decreased function compared with the LV (38 +/- 12 vs. 15 +/- 3). The control group demonstrated no differences in ventricular function. The authors concluded that global ischemia diminishes LV and RV function, and this effect is accentuated in the RV after LVAD support. In controls, RV function is not affected by LVAD support, but after ischemia, LVAD support alone often will be inadequate.