Takahiro Hisaoka

Comparison of the waveforms of transit-time flowmetry and intraoperative fluorescence imaging for assessing coronary artery bypass graft patency.

PurposeAn intraoperative fluorescence imaging (IFI) system, which can provide visual images, could be the common method for assessing graft patency intraoperatively. We conducted a prospective comparison of the diagnostic accuracy of both the fast Fourier transformation (FFT) analysis of transit-time flowmetry (TTFM) waveform and the IFI system to determine graft failure.MethodsThe study included 10 saphenous vein grafts (SVGs), all of which were aortocoronary grafts. Each patient underwent isolated coronary artery bypass grafting (CABG), including conventional CABG or off-pump CABG, and then underwent X-ray angiography after CABG. When intraoperative hemodynamics had stabilized, the grafts were evaluated with both the IFI system and TTFM. Based on the obtained flow profile of TTFM, certain variables were calculated. The waveforms of TTFM were analyzed with the FFT series. Harmonic distortion (HD) was calculated from the amplitudes, and the fundamental frequency was thus determined using the FFT series.ResultsThe IFI system demonstrated a satisfactory flow of all grafts. X-ray angiography demonstrated that one SVG was 75% stenosed, and the others were patent. The mean graft flow (MGF) and the pulsatility index (PI) of the patent SVGs were not significantly different from those of the stenosed SVG. The HD of the patent SVGs was significantly different from that of the stenosed SVG.ConclusionThe HD of the TTFM waveform can provide better diagnostic accuracy for detecting clinically significant grafts than MGF and PI of TTFM and the IFI system.

Ultrasonographic measurement of intima-media thickness of the carotid artery before coronary artery bypass grafting.

PurposeWe evaluated the usefulness of measuring intima-media thickness (IMT) of the carotid artery by ultrasonography before coronary artery bypass grafting (CABG).MethodsSeventy-three patients who underwent carotid ultrasonography before CABG were selected for this study. The maximum IMT (max IMT) in the bilateral common carotid artery was used as the index of carotid ultrasonography. As a quantitative measure of coronary atherosclerosis, we calculated Gensini’s coronary score (GCS) from the preoperative coronary angiography.ResultsThere was a positive correlation between the max IMT and the GCS. Furthermore, the max IMT of the patients with myocardial infarction was significantly greater than that of the patients with angina pectoris.ConclusionsCarotid ultrasonography before CABG is useful, not only for the morphological evaluation of the stenotic lesions of the neck vessels, but also for the quantitative prediction of atherosclerosis in the native coronary artery. The max IMT may predict the progression of atherosclerotic change of the native coronary artery from angina pectoris to myocardial infarction.

Total cavopulmonary connection with straight conduit for apicocaval juxtaposition

If the heart is malpositioned with apicocaval juxtaposition (ACJ), what constitutes the ideal course for the conduit pathway of a total cavopulmonary connection must be considered. When the conduit is positioned between the inferior vena cava and the same side of the pulmonary artery behind the ventricle, potential stenosis of the conduit due to compression by the ventricle or obstruction of the pulmonary vein due to compression by the conduit must be recognized. We reported two cases of ACJ in which a straight conduit pathway behind the ventricle was accomplished. Comprehensive dissection of the heart, especially the posterior side of the ventricle, to make a wide opening into the thoracic cavity is needed to obtain enough space behind the ventricle. Postoperative catheter studies performed 6 months after the operations showed no obstruction or deformity of the conduit or the pulmonary veins, and the mean pulmonary artery pressure measured 9 mmHg in both patients.

Avoiding Homologous Blood Transfusion Ameliorates Postoperative Lung Oxygenation in Pediatric Open Heart Operations

白血球除去フィルターを用い術中輸血中の同種血白血球を除去することで術後の肺酸素化能が改善することが明らかになっているが,最近われわれは小児開心術において輸血合併症予防のため,術前自己血貯血による無同種血輸血手術を積極的に行っており,これらの症例では同種血白血球のみならず血漿成分も入らないため体外循環に起因する炎症反応による肺障害がより軽減される可能性がある.そこで無輸血手術を達成できた小児心室中隔欠損例での術後呼吸機能を輸血症例と比較してみた.われわれの術前貯血プロトコールに従って同種血輸血手術を回避できた体重10kg以上の小児心室中隔欠損例16例(自己輸血群)の体外循環離脱直後から術後6時間までの肺酸素化能をrespiratory indexを算出することで評価した.これを同一疾患の同種血輸血症例(白血球除去フィルター使用:他家輸血群)17例と比較検討した.また術後挿管時間,白血球数,CRPも比較した.患児の年齢,体重は自己輸血群3.4±0.6歳,14.3±1.5kg,他家輸血群4.2±0.4歳,15.7±0.8kgと有意差を認めなかった.術後の挿管時間に両群間で有意差はなかった.体外循環直後,手術直後でのrespiratory indexは両群間で差はなかったが,他家輸血群が術後から再び悪化しているのに対し自己輸血群では時間経過に伴う悪化はなく,術後3時間,6時間には0.43±0.08,0.38±0.07と,他家輸血群(0.79±0.15,1.60±0.17)に比し有意に低値をとった(それぞれp<0.05,0.01).白血球数は術前,術後1日,1週間で両群間に有意差はなかった.CRPも術前,術後1日,1週間,2週間で有意差はなかった.10kg以上の軽症例で行っている自己血貯血による小児無同種血輸血手術では他家輸血例に比べrespiratory indexは術後3,6時間で有意に低値をとり,術後管理がより安全に行えることが実証された.自己血貯血による小児無同種血輸血開心術は輸血回避のみならず術後肺障害の改善にも有用であることが確認された.