Hirokazu Ohashi

Angiographic evaluation of the luminal changes in the radial artery graft in coronary artery bypass surgery: a concern over the long-term patency

OBJECTIVE The radial artery graft (RA) still involves two unsolved problems, namely, vasospasm and intimal hyperplasia, although satisfactory early and mid-term outcomes have been obtained recently. METHODS Two hundred patients underwent coronary artery bypass surgery with RA between October,1996 and December,2000. We made a comparison of the luminal diameters at early and mid-term periods in 23 patients who underwent mid-term angiographies after a mean follow-up of 27 months. The proximal anastomoses of the RA were the ascending aorta in these patients. The G/N ratio was determined as a ratio of the luminal diameter of the graft to that of the revascularized coronary artery so as to evaluate the luminal discrepancy between the graft and the native artery. RESULTS In the 122 patients who underwent angiographies about one month after the operation, the patency rate was 99% (144 of 145) in the RA, 97% (139 of 143) in the left internal thoracic artery graft (LITA), 96% (75 of 78) in the saphenous vein graft (SV). In the 23 patients who underwent mid-term angiographies, the patency rate was 91% (24 of 26) in the RA, 100% (23 of 23) in the LITA, and 83% (20 of 24) in the SV. The luminal diameters of the RA and LITA significantly increased from 2.15 to 2.52 mm, and from 1.75 to 1.97 mm, respectively. The luminal change from 3.78 to 3.33 mm in the SV was not significant. The G/N ratios changed from 1.10 to 1.31, from 1.01 to 1.13, and from 2.05 to 1.86 in the RA, LITA, and SV, respectively. The change of the RA alone was statistically significant. CONCLUSIONS The angiographic early patency rate was almost the same in three kinds of graft material, but the mid-term patency rate of the RA was between those of the LITA and SV. The mid-term luminal dilatation of the RA could involve two conflicting characteristics, namely, a good intimal function and a propensity to increase in the luminal discrepancy. Therefore, a further observation is required to evaluate whether the clinical outcome of the RA could remain as good as that of the LITA in the long-term period.

Evaluation of coronary artery bypass grafts using helical scan computed tomography.

The patency of coronary artery bypass grafts was evaluated by helical computed tomographic (CT) scan. One hundred forty patients who received an enhanced chest CT scan and a coronary angiography after bypass surgery were studied before discharge at the Fukui Cardiovascular Center. Among them was a total of 398 grafts and 436 anastomoses. For the evaluation of 248 vein grafts, the CT scan showed a 99.5% correct positive ratio and an overall accuracy of 96.4%. In 122 internal thoracic arteries tested, an overall accuracy of 64.7% was obtained. In gastroepiploic artery tests the overall accuracy was 33.3% and in radial artery tests it was 45.5%. Thirty‐seven venous sequential anastomoses in 34 grafts and 1 internal thoracic artery sequential anastomosis were also evaluated. In the venous sequential anastomosis, the CT scan showed a 73.0% of accuracy overall. This study showed that the helical CT scan was useful to evaluate graft patency following bypass surgery. Cathet. Cardiovasc. Intervent. 46:322–326, 1999.

Open heart surgery for posttraumatic inferior vena caval thrombosis

A 40-year-old woman was diagnosed as intrahepatic hematoma after blunt abdominal trauma. One month later computed tomography (CT) revealed the inferior vena caval thrombus extending into the right atrium. Emergency thrombectomy was performed under cardiopulmonary bypass. We believe that the thrombus, which was derived from laceration of the hepatic vein, extended through the inferior vena cava into the right atrium, and was the eve of pulmonary embolization. CT study should be repeated, once the intrahepatic hematoma was recognized. We emphasize that we should recognize the existence of such complication to prevent the catastrophic result.

Batista’s operation with coronary artery bypass grafting and mitral valve plasty for ischemic dilated cardiomyopathy

A 52-year-old male was admitted for angina pectoris and congestive heart failure classified as New York Heart Association class III. Coronary angiography showed 95% stenosis in the left anterior descending artery, 99% stenosis in the first diagonal branch, total occlusion in the left circumflex artery, and a hypoplastic right coronary artery. Left ventriculography showed a severely dilated left ventricle (ejection fraction 20%) and mild mitral regurgitation. In the myocardial scintigram using 99m-tetrofosmin, there was no viability in the posterolateral wall although the other wall was viable. Partial left ventriculectomy, which is called Batistas operation, coronary artery bypass grafting and Alfieris mitral valve plasty were performed concomitantly. Postoperatively, the ejection fraction was improved to 39%, and all grafts were patent. The patient was discharged in New York Heart Association class I. We concluded that to succeed in partial left ventriculectomy for ischemic dilated cardiomyopathy, not only should there be no viability in the posterolateral wall to be resected for volume reduction, but the coronary artery which perfuses the residual myocardium with viability should be graftable.

A Case Report of Dor's Operation for Left Ventricular Aneurysm with Cardiac Failure 19 Years after the Operation for Post Infarction Ventricular Septal Perforation

症例は70歳男性.1982年に前壁中隔領域の急性心筋梗塞後の心室中隔穿孔に対してlinear法にてVSP閉鎖術を施行されている.軽快退院後外来経過観察中であった.術後19年目に心不全をきたし再入院.心カテーテル検査にて広範囲な左室心尖部および中隔側のasynergyを認めた.LVEF39%,LVEDV200mlであった.手術は体外循環,心室細動下にDor手術と左回旋枝への1枝バイパスを行った.術後経過は良好で,術後33日目に軽快退院した.前回の手術ではlinear法を用いて左室切開線を閉鎖した結果,遠隔期に広範囲akinesisを認めるにいたった.今回Dor手術を行い,術後著明な改善が認められた.このことは,linear法による瘤切除よりもDor手術の優位性を示すものと考えられた.

Pedunculated hemangioma in the right ventricle

We report a rare case of right ventricular hemangioma. In an asymptomatic 56-year-old man, echocardiography as a part of medical checkup demonstrated a pedunculated tumor, 1.0 x 1.3 x 1.5 cm, arising from the free wall of the right ventricle. No findings were seen of a feeding artery to the tumor or vascular blush in preoperative coronary angiography. Successful resection was done through right atriotomy under total cardiopulmonary bypass. The histological examination revealed capillary hemangioma. The postoperative clinical course was uneventful, but requires careful follow-up for possible coronary cardiac fistula. This is the fifth case of right ventricular hemangioma, to our knowledge, ever reported in Japan.

Ultrasound Vasography Evaluation of Radial Arterial Grafts used for Coronary Arterial Bypass Surgery

OBJECTIVES For coronary bypass surgery, radial arteries are often used as bypass grafts. Some of these arteries however, have arteriosclerotic lesions. We attempted to evaluate the relationship between arteriosclerosis and vasodilation. METHODS Prior to bypass surgery, 20 patients underwent ultrasound vasography to determine the condition of their radial and brachial arteries. Flow-mediated dilation, which is the same as endothelium-dependent vasodilation, was measured in the brachial artery of the nondominant arm by reactive hyperemia after 5-minute forearm ischemia. Vasodilation after application of a sublingual glyceryl trinitrate spray was also measured. RESULTS During surgery, 4 of 20 radial arteries demonstrated calcification, and 3 of the 4 could be used by removing the calcified part. However, the other artery, which had extensive calcification that could not be detected by ultrasound vasography, was discarded. The amount of vasodilation seen after the administration of sublingual glyceryl trinitrate had no correlation with calcified grafts. Calcified radial arteries demonstrated significantly poor brachial artery vasodilation by an endothelial-dependent vasodilation test. CONCLUSIONS Calcification in radial arteries can thus only be evaluated by flow-mediated dilation.