Intracoronary Shunt Research Articles

Cirugía coronaria sin circulación extracorpórea y estabilizador cardíaco Octopus®

Between june and july, 1998, surgical myocardial revascularization without cardiopulmonary by-pass through a conventional sternotomy with the use of the "Octopus" heart stabilizer was performed in 6 patients (mean age 63 years, range 49-74 years). All patients received an internal thoracic artery graft. Three of them had also a saphenous vein graft on the distal right coronary artery. An intracoronary shunt was used in four patients and all the anastomoses were accomplished in a completely immobilized area of epicardium. Mean postoperative hemorrhage was 200 ml (50-300 ml) and ICU and total hospital stay were 2 and 6 days respectively. At the first follow-up control, one month post-op, all six patients are free of symptoms without medication. We believe the "Octopus" tissue stabilization system outperforms other heart stabilization devices in our hands and it can be used safely in selected groups of patients.

心拍動下冠状動脈バイパス術における冠状動脈内シャントの有用性

心拍動下冠状動脈バイパス術は吻合時の無血視野を得るために, 冠状動脈の閉塞が必要となる. 閉塞部遠位での心筋虚血を予防するために, 冠状動脈内シャントチューブを用い, その有用性を正常ブタ心にて検討した. 冠状動脈シャントチューブを用いたS群 (n=3) と用いないC群 (n=4) で検討したところ, S群では吻合直後に心電図上, 1例にSTの上昇を認めたほかは, STの変化を認めなかった. また, 酵素上は, CPK-MB, トロポニンTともにほぼ不変であった. 手技上の点からシャントチューブは吻合の妨げにはならなかった. 他方, C群では, 1例を除き, 吻合中に心室細動となり, 電気的除細動にても調律を回復し得なかった. 以上の点から, 冠状動脈内シャントチューブは有用と考えられた.

Técnica de revascularização miocárdica com uso de toracoscopia

The benefits of the internal mammary artery (IMA), as a graft, particularly for the left anterior descending (LAD) coronary artery disease, have been demonstrated. Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) is now an accepted technique of myocardial revascularization. Thoracoscopy and a minimal thoracotomy have been applied to cardiac surgery, however its use has not been well defined. In our approach, we harvested the left or the right IMA thoracoscopically. Following this the left IMA-LAD or right IMA-right coronary artery anastomoses were fashioned, by means of a left or right small anterior thoracotomy on the beating heart without CPB. A double lumen endotracheal tube was used so the lung could be collapsed. Three left or right lateral chest ports of 1.5 cm were made, and the thoracoscope was placed through the initial port, permitting inspection of the thorax. The other ports were used for IMA dissection, using endoscopic instruments (electrocautery, grasping, forceps,...), the side branches were controlled by either cautery or endoscopic clips. When it was possible, the anterior port was extended doing a small left or right anterior thoracotomy, the pericardium was exposed, the IMA was divided and exteriorized through the thoracotomy. After coronary artery control, the bypass graft was carried out on the beating heart without CPB. In certain cases, when myocardial protection was considered to be essential, this was achieved by means of an intracoronary shunt. We have operated on more than 20 patients using this technique with good results in all cases. We believe that with increasing operator experience, this minimally invasive approach will have a major impact on the management of the coronary artery disease patients, with a faster recovery, shorter hospitalization, and certainly less cost.

Myocardial energetics and clinical response to the cardiotonic agent MDL 17043 in advanced heart failure

Cardiotonic agents may prove useful in the long-term treatment of chronic heart failure provided myocardial efficiency is enhanced and clinical status is improved. Accordingly, the short-term hemodynamic and clinical response to the phosphodiesterase inhibitor, MDL 17043, was evaluated. Intravenous increments of 0.05 mg/kg (maximal total 3 mg/kg) were given to a peak cardiac output response in 13 patients with New York Heart Association functional class IV heart failure secondary to ischemic or myopathic disease. Significant (p less than 0.05) responses at peak effect (1.7 mg/kg) included an increase in cardiac output (3.5 to 4.6 liters/min) and heart rate (86 to 90 beats/min) and a decrease in pulmonary capillary wedge (25 to 17 mm Hg), mean arterial (85 to 78 mm Hg) and right atrial (10 to 7 mm Hg) pressures. Coronary sinus flow (measured in nine patients) increased (122 to 144 ml/min, p less than 0.01) as did myocardial oxygen uptake (14.1 to 15.1 ml/min, p less than 0.01), whereas myocardial extraction of oxygen (78 to 72%, p less than 0.01) and lactate (24 to 9%, p less than 0.01) decreased with three patients producing lactate at the time of their peak cardiac output response. Nine of the 12 patients given long-term oral therapy improved at least one functional class at 2 weeks. This improvement was sustained at 20 weeks in five patients. Thus, MDL 17043 acutely improves the function of the failing heart. However, the decrease in oxygen extraction occurring with increased myocardial oxygen uptake suggests that intracoronary shunting may occur along with an increase in oxygen demand and contribute to myocardial anaerobiosis in some patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced incidence of intraoperative myocardial infarction during coronary bypass surgery with use of intracoronary shunt technique

Intraoperative myocardial infarction is a recognized complication of aortocoronary bypass surgery. One major cause of such infarction may be interruption of coronary blood flow, particularly in patient with poor coronary collateral circulation. In 30 patients use of an intracoronary shunt made it possible to limit the period of coronary occulusion during graft construction to a few minutes. Use of this shunt was associated with a reduced incidence of intraoperative myocardial infarction (as judged by the appearance of new Q waves) when these patients were compared with 50 patients operated on without this procedure (6 of 50 [12 percent] versus 0 of 30). The incidence of postoperative persistent S-T segment elevation was reduced from 21 of 50 (42 percent) to 5 of 30 (17 percent). Except for use of the shunt, the surgical technique was identical in the two groups of patients.