近赤外分光法を利用した心筋酸素代謝マッピング法による心拍動手術の基礎的研究

金沢大学附属病院目的:常温酸素化血液逆行性冠潅流による心拍動下心内手術法を確立すること。方法実験1;冠灌流の血流量を10分間隔で5.0〜10.0ml/kg/minに変化させ、心筋組織酸素飽和度と心筋組織血流を心室筋表面4箇所で同時測定し、至適冠灌流量を検討した。実験2;実験1で得られた至適血流量にて120分間の逆行性冠灌流を行い、灌流前後で心機能評価と、心筋障害の程度評価を行い、本方法の臨床応用の妥当性を検討した。結果1.逆行性冠灌流7.0〜7.5ml/kg/minにて心筋酸素飽和度、心筋血流が最も安定した値(約80%、88mL/min/100g)となり至適灌流量であることが判明した。2.120分の持続灌流にて心筋酸素飽和度は75〜83%、心筋血流は97〜107mL/min/100gと安定した値を維持。3.血行動態 前 後心拍数 92.7bpm 90.3bpm平均血圧 73.7mmHg 71.8mmHg肺動脈圧 29.3mmHg 28.2mmHg肺動脈喫入圧 15.7mmHg 15.2mmHg心係数 53.0ml/min/kg 49.2ml/mm/kg と血行動態は120後も全く低下することはなかった。4.術後心筋障害の指標として測定したトロポニンT(pre0.045:peak0.082ng/mL)、CK-MB(pre4.1:peak5.2ng/mL)は術前後で上昇することなく、至適灌流量の120分潅流で心筋障害は認めなかった。結語以上の動物実験から、心拍動下心内手術を行うための至適流量は7.0〜7.5ml/kg/minであり、この逆行性灌流法により120分間は、心機能を低下させることなく安全な心拍動手術が可能であることが判明した。今後、本灌流方を臨床応用しさらに研究を進める予定である。研究課題/領域番号:14770676, 研究期間(年度):2002-2003出典：「近赤外分光法を利用した心筋酸素代謝マッピング法による心拍動手術の基礎的研究」研究成果報告書　課題番号14770676（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-14770676/)を加工して作

心筋酸素代謝からみた迷走神経心臓枝刺激による新たな心房除細動法の基礎的研究

金沢大学附属病院研究課題/領域番号:26462084, 研究期間(年度):2014-04-01 – 2017-03-31出典：研究課題「心筋酸素代謝からみた迷走神経心臓枝刺激による新たな心房除細動法の基礎的研究」課題番号26462084（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-26462084/）を加工して作

Total arterial revascularization with composite skeletonized gastroepiploic artery graft in off-pump coronary artery bypass grafting

AbstractBackgroundTotal arterial revascularization in coronary artery bypass grafting has recently become of great interest to many surgeons. At the same time, off-pump coronary bypass grafting has also become a popular procedure because of its low morbidity and mortality. Here we report our recent series of off-pump coronary bypass grafting performed with a grafting technique we developed by using the skeletonized gastroepiploic artery and the radial artery composite graft to achieve total arterial revascularization.MethodsFrom September 2000 to April 2003, 98 patients underwent total arterial revascularization with the skeletonized gastroepiploic artery and radial artery composite graft on the beating heart. We used the gastroepiploic artery graft of choice in patients with a right coronary artery lesion. When multiple grafting was required in inferior, posterolateral, or lateral ventricular walls and the gastroepiploic artery graft was too short to cover these areas, we used the composite grafting technique.ResultsThere were no in-hospital deaths and there was no severe morbidity among the study patients. Postoperative angiography showed graft occlusion at the anastomosis site between the gastroepiploic and radial arteries. The patency rate of the gastroepiploic arterial composite graft was 98.3% (118/120 distal anastomoses).ConclusionsA composite graft with the skeletonized gastroepiploic artery and the radial artery ensured sufficient caliber size and length for myocardial revascularization on inferior, posterolateral, and lateral ventricular walls. This composite graft can be used safely and effectively even in off-pump coronary bypass surgery with excellent early clinical and angiographic outcome in selected patients, although longer follow-up periods are necessary to draw definitive conclusions

Successful low-energy cardioversion using a novel biodegradable gel pad: Feasibility of treating postoperative atrial fibrillation in animals

ObjectivePostoperative atrial fibrillation is one of the most frequent complications of cardiac surgery. We developed a novel biodegradable gel pad consisting of biopolymers that directly attach to the myocardium by electrostatic interaction. The present study examines the feasibility and effectiveness of low-energy internal cardioversion using these pads.MethodsThe hearts of 6 pigs were exposed through a median sternotomy under general anesthesia, and 2 monopolar pacing wires were placed on the left pulmonary veins (chest open group). Two biodegradable cardioversion gel pads were placed on the right appendage and the left atria without suturing. All wires were extruded through the skin and secured with a suture. Sustained atrial fibrillation was induced by burst-pacing from the pulmonary veins in continuous 20-ms cycles. Shock intensity started at 0.5 J, and the energy level was increased in 0.5-J increments until cardioversion occurred. This protocol was repeated 5 times per pig. In a second group of 6 pigs (chest closed group), the epicardial cardioversion electrode gel pads and pacing wire electrodes were positioned as described above. Shock intensity was started at 0.5 J. If the shock was unsuccessful, the energy level was increased in 0.5-J increments until 2 consecutive cardioversions were achieved at a single energy level. At postoperative days 1, 3, 5, and 7, the defibrillation threshold was determined with the chest closed. At postoperative day 10, the cardioversion wires were removed. At predetermined time intervals, the heart was reexposed and the extent of degradation in vivo was visually evaluated and histologically assessed after sacrifice.ResultsAll pigs with induced atrial fibrillation were cardioverted to sinus rhythm on the determined postoperative day. The mean energy and lead impedance in the chest open group were 0.65 ± 0.23 J and 97.6 ± 5.52 Ω, respectively, and the overall values of mean energy and lead impedance in the chest closed group were 1.67 ± 1.00 J and 75.9 ± 13.3Ω, respectively. No complications were observed after wire removal. The gel pads became degraded and decreased in thickness, and signs of mild inflammation were evident on the gel pad. However, the gel pads did not elicit significant severe inflammatory reactions according to both gross and histologic assessments at 1 month after the surgery.ConclusionAtrial cardioversion using novel biodegradable gel pads that are easily affixed may afford a straightforward and effective treatment for atrial fibrillation after cardiac surgery

Subzero 24-hr nonfreezing rat heart preservation: A novel preservation method in a variable magnetic field

BACKGROUND: A new supercooling system using a variable magnetic field has been recently developed. Subzero nonfreezing preservation has been believed to be a beneficial method because of the lower metabolic rate. The purpose of this study was to evaluate the hemodynamic and metabolic effects of rat heart preservation in a variable magnetic field without cryoprotectants. METHODS: Rat hearts were perfused ex vivo for 120 min after 24-hr preservation in two groups (n=6 each): (1) conventional storage group, in which the hearts were stored at 4°C, and (2) the subzero group, in which the hearts were preserved at-3°C in a variable magnetic field. RESULTS: Reperfusion cardiac performance after preservation was significantly preserved in the subzero group compared with the conventional group with respect to heart rate, coronary flow, the peak positive dP/dt, and the peak negative dP/dt (P<0.05). Edema after reperfusion was significantly decreased (P<0.05), and the adenosine triphosphate level was higher in the subzero group (P<0.05). CONCLUSIONS: The rat hearts preserved in a variable magnetic field at-3°C showed better hemodynamic and metabolic performance than those preserved using conventional storage at 4°C. Copyright © 2012 Lippincott Williams &Wilkins

Potent Vasodilatory Effect of Fasudil on Radial Artery Graft in Coronary Artery Bypass Operations

Background: The radial artery (RA) is a useful conduit for coronary artery bypass grafting (CABG) but is susceptible to vasospasm during harvesting. We evaluated the usefulness of fasudil, a Rho kinase inhibitor, in dilating the RA graft and increasing graft free flow (GFF) compared with the conventional graft-dilating agents papaverine and verapamil-nitroglycerin (VG). Methods: Between June 2012 and January 2013, 45 patients with ischemic heart disease who underwent isolated CABG using the RA were enrolled and randomly assigned to fasudil (n = 15), papaverine (n = 15), or VG (n = 15). Fasudil (2.67 mmol/L), papaverine (1.0 mmol/L) mixed with heparinized blood, or VG (30 μmol/L each of verapamil and nitroglycerin) was injected intraluminally into the RA graft after harvesting. Main outcome measures were RA GFF, hemodynamic changes, and histopathologic examination of the RA. Results: In the fasudil group, GFF increased significantly (p < 0.001) from 36.8 ± 20.4 at baseline to 148.0 ± 88.3 mL/min after injection. GFF increased significantly (p < 0.001) from 36.0 ± 19.0 to 72.3 ± 36.7 mL/min in the papaverine group and increased significantly (p < 0.001) from 39.5 ± 23.3 to 64.3 ± 29.9 mL/min in the VG group. The GFF was significantly higher (p = 0.001) in fasudil-treated RA than in papaverine- or VG-treated RA. Histopathologically, RA graft diameter was markedly increased after fasudil injection, and the structure of the multiple elastic lamellae was intact. Blood pressure did not change significantly after drug injection in all groups. Conclusions: Fasudil exhibited a very potent vasodilatory effect on the RA compared with conventional papaverine or VG, resulting in increased GFF. This agent is useful for dilating RA grafts in CABG. © 2013 The Society of Thoracic Surgeons

内視鏡下のOPCAB

金沢大学医薬保健研究域医学系Since 1999, we have performed total endoscopic off-pump coronary artery bypass (OPCAB). Innovation of endoscopic optic techniques and development of endoscopic forceps were necessary to perform this procedure. The operative methods of the endoscopic OPCAB; a 12 mm port for 3-D endoscope is firstly inserted through the 5th intercostal space (ICS) in the mid axillary line, and then the left internal thoracic artery (LITA) is taken down in semi-skeletonized fashion using other 2 instrumental 5 mm ports (the 3rd, 6th anterior axillary ICS). To anastomose LITA to the left anterior descending artery (LAD), other 2 10 mm and 12 mm ports are inserted through the 4th ICS in parallel. A conventional end-to-side anastomosis is manually performed with 8-0 prolene. The average LITA harvesting time and anastomotic time have been shortened significantly thanks to the endoscopic innovation. However, there are some limits to manual manipulations in the endoscopic OPCAB. Robotic surgery might have more advantages to the flexibility of forceps tips. The introduction of robotic surgery system is indispensable to safe and certain endoscopic OPCAB

Fasudil is a superior vasodilator for the internal thoracic artery in coronary surgery

Background: The internal thoracic artery (ITA) is a very useful conduit for coronary artery bypass artery (CABG), with excellent long-term patency. With the purpose to dilate the ITA graft and increase graft free flow (GFF) intraoperatively, we evaluated the usefulness of intraluminal injection of fasudil, a Rho-kinase inhibitor, in comparison to the conventional graft dilating agent, papaverine. Methods: Between June 2011 and January 2012, 30 patients with ischemic heart disease who underwent isolated CABG using ITA were enrolled. The patients were randomly assigned to 2 groups: the fasudil group (n = 15) in which fasudil solution 0.9 mg/dL was injected into the ITA, and the papaverine group (n = 15) in which papaverine solution (0.4 mg/mL) mixed with heparinized blood was used. Outcome measures were left ITA GFF, heart rate, and mean blood pressure during flow measurements, and histopathologic examination of the ITA. Results: In the fasudil group, GFF increased significantly (p < 0.01) from 19.7 ± 15.2 mL/minute at baseline to 66.9 ± 31.7 mL/minute after fasudil injection. In the papaverine group, GFF increased significantly (p < 0.01) from 22.9 ± 17.3 mL/minute at baseline to 44.8 ± 26.7 mL/minute after papaverine injection. Blood pressure and heart rate did not change significantly after drug injection in both groups. The GFF was significantly higher (p = 0.038) in fasudil-treated ITA than in papaverine-treated ITA. Histopathologically, the diameter of the ITA was markedly increased after fasudil injection. Elastica van Gieson staining showed that the multiple elastic lamellae structure was intact. Conclusions: Fasudil exhibited very potent vasodilatory effect on the ITA compared with conventional papaverine resulting in increased GFF. This agent is a useful graft dilating agent. © 2013 The Society of Thoracic Surgeons