Teruaki Ushijima

Use of the Radial Artery Graft After Transradial Catheterization: Is It Suitable as a Bypass Conduit?

BACKGROUND The suitability of the radial artery after transradial catheterization as a bypass conduit has been of great concern to surgeons. METHODS A total of 67 patients underwent isolated coronary artery bypass grafting using the radial artery: 22 patients received preoperative transradial catheterization (group 1) and 45 patients did not receive transradial catheterization (group 2). Those patients were retrospectively reviewed. RESULTS Patient characteristics, operative procedures, and early clinical outcome were not different between groups. The stenosis-free graft patency rates in groups 1 and 2 were 88% (16 of 18 patients) and 90% (38 of 42 patients) in the left internal thoracic artery (p = 0.87); 77% (17 of 22 patients) and 98% (48 of 49 patients) in the radial artery (p = 0.017); and 87% (13 of 15 patients) and 84% (21 of 25 patients) in the saphenous vein (p = 0.42), respectively. Intimal hyperplasia of the radial artery was observed in 68% (11 of 16 patients) in group 1 and in 39% (14 of 34 patients) in group 2 (p = 0.046). CONCLUSIONS Transradial catheterization reduced early graft patency and caused intimal hyperplasia, although it did not affect early clinical outcomes. We suggest that the use of the radial artery as a bypass conduit after transradial catheterization should be undertaken cautiously.

Is internal thoracic artery grafting suitable for a moderately stenotic coronary artery

Abstract Grafting an internal thoracic artery to a coronary artery with moderate stenosis remains controversial. Competitive flow from the native coronary artery has been proposed as the cause of distal narrowing and ultimate failure of the internal thoracic artery graft. We investigated intraoperative phasic blood flow in internal thoracic arteries grafted to coronary arteries with various degrees of stenosis and the influence of stenosis on postoperative angiographic findings. One hundred patients who underwent coronary artery bypass grafting of an internal thoracic artery to the left anterior descending coronary artery were divided into three groups according to degree of coronary stenosis. Group 1 included 39 patients who had 75% or less stenosis, group 2 included 34 patients with stenosis from 76% to 90%, and group 3 included 27 patients with stenosis greater than 90%. Mean flow and peak systolic flow of internal thoracic artery graft in group 1 were lower than those in group 2 ( p p p

Internal thoracic artery graft function during exercise assessed by transthoracic Doppler echography.

BACKGROUND Noninvasive quantitative assessment of internal thoracic artery (ITA) graft function at rest and during exercise is important in patients who have undergone coronary artery bypass grafting. METHODS Blood flow in the ITA graft was measured using transthoracic color Doppler echography before and after operation in 50 patients who underwent coronary artery grafting using an ITA to the left anterior descending artery. The patients were divided into three groups according to the degree of coronary stenosis and previous anterior myocardial infarction: Group 1 included 12 patients with severe (90% or more) coronary stenosis accompanied by anterior infarction. Group 2 included 26 patients with severe coronary stenosis without anterior infarction. Group 3 included 12 patients with moderate (75% or less) coronary stenosis without anterior infarction. Transthoracic echographic images of the ITA were obtained through the first intercostal space using a 7.5-MHz probe, and the diameter and cross-sectional area of the ITA were measured on B-mode imaging. Systolic, diastolic, and mean blood flow velocity and volume were measured by the Doppler method. RESULTS Internal thoracic artery diameter increased significantly from 2.2 mm to 2.4 mm after operation. The ITA flow patterns in both flow velocity and volume changed from systolic-dominant to diastolic-dominant after operation. Postoperative ITA graft flow was 82 +/- 24 mL/min, 53 +/- 30 mL/min, and 31 +/- 15 mL/min (p < 0.01, group 1 versus 3; p < 0.05, group 1 versus 2) and percent diastolic fraction of ITA flow was 72%, 68%, and 62% (not significant) in groups 1, 2, and 3, respectively. Compared with intraoperative ITA flow, which was measured using an ultrasound transit-time flowmeter, postoperative ITA graft flow was increased in group 1, but not changed in group 2 or 3. The ITA graft flow was measured before and after exercise in 19 patients and was compared with ITA flow in 10 normal control subjects. The ITA graft flow increased significantly with exercise in all patients in the three groups. Percent diastolic fraction of ITA flow increased significantly with exercise in patients with severe coronary stenosis (groups 1 and 2), but decreased significantly in patients with moderate stenosis (group 3). CONCLUSIONS Changes in native coronary artery and ITA graft may be predicted by assessing ITA flow pattern during exercise. Transthoracic color Doppler echography is a clinically useful noninvasive method of assessing ITA graft function at rest and during exercise.

Late patency of the left internal thoracic artery graft in patients with and without previous successful percutaneous transluminal coronary angioplasty

The aim of this study was to compare early and late graft patency in patients with and without previous successful PTCA. Of the 70 patients who received both early and late follow-up angiography, 13 patients who had received successful PTCA at the left anterior descending coronary artery (LAD) before CABG (group I) and 31 patients who had not received preoperative PTCA in any vessel (group II) were retrospectively reviewed. There were no significant differences in patient characteristics including major coronary risk factors. The mean duration between the operation and control angiography was 35+/-23 months in group I and 36+/-19 months in group II (P=0.90). Occlusions of the LITA graft were observed in four patients of group I and in four patients of group II. Cumulative patencies of the LITA graft were 54% in group I and 83% in group II (P=0.12). The late patency rate of the LITA graft bypassed to the LAD in patients that received previous successful PTCA in the coronary artery tended to be lower than in patients without previous PTCA. This result should be confirmed by further prospective studies.

Removal of infected pacemaker lead through sternotomy without cardiopulmonary bypass

A 66-year-old man, who had undergone DDD pacemaker implantation for complete A-V block two years ago, was admitted because of endocarditis with septicemia and renal failure. His blood culture revealed Staphylococcus aureus. We tried to remove the infected cardiac pacemaker lead. But we failed to remove the atrial lead because it was strongly adhered with the right atrial appendage. Antibiotic therapy was ineffective. In the last resort, we operated through median sternotomy three months after the initial infectious episode. In intraoperative inspection, we found it difficult to remove the lead by traction because of atrial residual lead sticking out of the right atrial appendage. We applied a purse string suture on the right appendage and obtained successful removal of infected lead without the cardiopulmonary bypass. His postoperative course has been uneventful. He is totally asymptomatic and doing well up to now. In case of such local infection, we conclude that all transvenous leads should be removed and recommend a simultaneous implantation of the epicardial pacemaker system.

Gastroepiploic artery graft angiography via brachial approach using a Yumiko catheter.

We report here our initial experience in angiography of gastroepiploic artery (GEA) grafts via a brachial approach using the Yumiko catheter regarding technical aspect. Good‐quality GEA angiography was obtained in 12 (86%) of 14 patients using our technique. GEA graft angiography can be performed using the Yumiko catheter via a brachial approach. This technique may be less stressful for patients receiving coronary catheterization, including GEA graft angiography. Catheter Cardiovasc Interv 2004;61:350–353.

Arterial revascularization. 18-year experience with coronary artery bypass grafting in familial hypercholesterolemia.

Familial hypercholesterolemia is characterized by a high plasma level of cholesterol and is frequently associated with rapidly progressing coronary heart disease. The internal thoracic artery is recognized as the conduit of choice for coronary artery bypass grafting. This study was performed to determine whether multiple arterial grafting was associated or not with additional benefits for patients with familial hypercholesterolemia. Between June 1980 and March 1998, 95 patients with familial hypercholesterolemia. underwent a total of 103 coronary artery bypass procedures with one hospital death. The patients were divided into 3 groups according to the type of bypass graft. Group 1 included 31 patients with only saphenous vein grafts; Group 2,48 patients with one arterial graft and supplemental vein grafts; and Group 3, 24 patients with multiple arterial grafts. The overall actuarial survival rate was 90.9% at 10 years and 81.8% at 18 years. The overall actuarial freedom from recurrent angina was 68.9% at 10 years and 55.8% at 16 years. The actuarial survival rate in group 2 was higher than that in Group 1 (p < 0.05). There was no difference in the actuarial survival or in the freedom from cardiac events between Group 2 and Group 3. Single arterial grafting improved the long-term survival in patients with familial hypercholesterolemia. However, no additional benefit from multiple arterial grafting was identified.

How I do it: high-quality intraoperative fluorescence imaging in off-pump coronary artery bypass grafting.

We have developed a simple technique for establishing high-quality intraoperative fluorescence imaging in off-pump coronary artery bypass grafting. The technique of transaortic injection of indocyanine green is an effective method of achieving clear fluorescence imaging and for evaluating the quality of graft anastomoses. We consider the images obtained with this technique to be equivalent to those obtained by conventional coronary angiography with selective enhancement of the graft.

Skeletonized arterial graft holder for coronary artery bypass grafting

A skeletonized arterial graft holder, designed for use during off-pump coronary artery bypass grafting, is described. This new holder is atraumatic and holds a skeletonized arterial graft securely during anastomosis. It helps the operator to make the first several stitches avoiding graft injuries, and the use of this instrument facilitates the use of skeletonized arterial grafts for coronary artery bypass grafting.

Power Acquisition from Preconditioned Muscle by Low Power/High Stroke Energy Converter in Artificial Heart Drive

In a chronic study, the preconditioned skeletal muscle ventricle has been reported, to show reduction of stroke volume and marginal power as a substitute for the systemic ventricle; the use of linearly-contracted skeletal muscle as an energy source for cardiac assist devices therefore provides a potential alternative. The present study evaluated the power output of linearly contracted skeletal muscle, after preconditioning, for driving an artificial heart via a muscle energy converter. The right latissimus dorsi muscles (LDMs) of ten mongrel dogs were dissected, with the preservation of collaterals, and preconditioned for a mean duration of 8.8 weeks without vascular delay. The LDM, freed at the humeral insertion, was connected to a low power/high stroke energy converter (LP) or a high power/ low stroke energy converter (HP) for the artificial heart and the power output was tested through the performance of a 20-ml blood pump in a mock circuit. At 20mmHg mean afterload, the HP converter produced an output of 0.12 ± 0.01 mW/g and the LP, an output of 0.14 ± 0.01 mW/g, with outputs being 0.51 ± 0.03mW/g and 0.61 ± 0.06mW/g, respectively, at 80mmHg mean afterload. Power translation with the LP converter is more advantageous for power acquisition from the power-limited preconditioned skeletal muscle than with the HP converter. The preconditioned linear muscle provided 69% of the power for a fully-ejected artificial heart at systemic afterload and power almost equivalent to 112% of the canine left ventricle when the canine heart rate was adjusted by a pump rate of 60bpm.