Biomedical subjects

Hiroshi Nagamine

Publications and source records attributed to Hiroshi Nagamine.

12 recordsLinked to original sources

PubMed2006

Hybrid surgical angiogenesis: omentopexy can enhance myocardial angiogenesis induced by cell therapy.

BACKGROUND: The conditions at the injection site are important in cell transplantation for severe ischemic heart disease. The omentum is both a well-vascularized tissue and a source of angiogenic factors. We examined the effectiveness of autologous bone marrow-derived mononuclear cells (BM-MNCs) with or without omentopexy in a large animal model. METHODS: Myocardial infarction was generated in the lateral wall by ligation of coronary artery branches in miniswine. Animals received BM-MNC injection with or without omentopexy. Controls received saline only. Three weeks after surgery, regional myocardial blood flow and contractility were measured, and density of arterioles was evaluated immunohistologically. Angiography and postmortem examinations were performed to determine collateral communication. RESULTS: Regional myocardial contractility was significantly improved by BM-MNC transplantation both with and without omentopexy (0.29 +/- 0.02 vs 0.11 +/- 0.03, p < 0.01, 0.30 +/- 0.02 vs 0.12 +/- 0.01, p < 0.01, respectively). Relative regional myocardial blood flow in the combined omentopexy group was significantly higher than the controls both at rest (1.05 +/- 0.11 vs 0.57 +/- 0.07, p < 0.01) and under stress (1.09 +/- 0.08 vs 0.40 +/- 0.10, p < 0.01). The number of arterioles (< 50 microm) in both groups were higher than the controls (88.1 +/- 5.00 vs 38.1 +/- 8.99, p < 0.01 and 109.2 +/- 9.91 vs 38.1 +/- 8.99, p < 0.01, respectively). The number of large arterioles (> 50 microm) in the combined omentopexy group was significantly higher than in both BM-MNC alone (26.9 +/- 2.4 vs 17.6 +/- 1.8, p = 0.011) and controls (26.9 +/- 2.4 vs 10.0 +/- 1.3, p < 0.01). Collateral communication between the omentum and myocardium was demonstrated by angiography and postmortem injection. CONCLUSIONS: The BM-MNC transplantation may attenuate cardiac contractile dysfunction, and omentopexy may enhance angiogenesis induced by BM-MNC transplantation.

Angiography↗

PubMed2006

An innovative balloon-type surgical device for atrial fibrillation.

BACKGROUND: The maze procedure and its modifications are the surgical treatment for atrial fibrillation. In an attempt to achieve a less invasive operation, we developed a balloon-type device for electric pulmonary vein isolation and evaluated its effectiveness macroscopically and microscopically. METHODS: We created a left heart system model from 20 pigs. Based on a mold, a balloon was made with silicone resin. When this balloon was inflated, all pulmonary vein orifices were pressed and ablated by probes using radiofrequency and cryotherm as energy sources. Macroscopic and microscopic evaluations were performed. RESULTS: Complete circular ablation by radiofrequency was confirmed in 2 of 3 veins. The transmural denaturation was pathologically confirmed in all areas ablated at 80 degrees for 2 minutes. The complete circular ablation line and the transmural denaturation were macroscopically and microscopically confirmed after cryoablation at -100 degrees for 2 minutes using liquid nitrogen. CONCLUSIONS: This study proved that the balloon is effective in simplifying pulmonary vein isolation and has potential to become an instrument that contributes to less invasive operations in the near future.

Animals↗

PubMed2005

Off-pump CABG with synchronized arterial flow ensuring system.

PURPOSE: We developed a synchronized, arterial-flow, ensuring system to perform coronary anastomoses safely without any ischemia-related event. DESCRIPTION: Arterial blood is removed from the femoral artery. The resulting blood passes a switching valve and is pumped out to a syringe pump. This pump controller provides pulsatile arterial blood flow synchronized with the diastolic phase on an electrocardiogram. The arterial blood is perfused to the coronary artery through a fine flexible cannula during anastomosis. EVALUATION: From February 1999, 524 consecutive patients were operated on using the synchronized arterial flow ensuring system. Mean duration for each anastomosis was 7.6 +/- 3.3 minutes (range, 4 to 20 min). There were no intraoperative fatal arrhythmias, ventricular arrhythmias, or short-run or hemodynamic deterioration during anastomoses. No hospital death was observed, and postoperative myocardial infarction occurred in 2 patients (0.4%). Postoperative angiography showed a 98.1% patency rate. CONCLUSIONS: The early clinical and angiographical results for off-pump CABG with the synchronized arterial flow ensuring system were excellent without mortality. We believe that off-pump CABG can be more safely performed using the synchronized arterial flow ensuring system based on our favorable results.

Aged↗

PubMed2005

The technical aspect of the gastroepiploic artery graft skeletonization with the harmonic scalpel: the samurai technique.

A novel skeletonization technique using the scissors-type harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH, USA) is presented. This "samurai technique," which uses the harmonic scalpel by frequently turning over the scissors, facilitates the handling of the gastroepiploic artery, enlarges the caliber size, and allows easy skeletonization without any vessel injury.

Coronary Artery Bypass↗

PubMed2004

Intramyocardial CD34+ cell transplantation combined with off-pump coronary artery bypass grafting.

This report describes a new therapeutic approach for severe ischemic heart disease, intramyocardial transplantation of autologous bone marrow-derived CD34 + cells combined with off-pump coronary artery bypass grafting (CABG). CD34 is widely known as a cell surface antigen expressed on hematopoietic stem cells, and recent experimental studies have shown that CD34 + cells include endothelial progenitor cells. We used the Isolex 300i magnetic cell selection system to separate CD34 + cells from bone marrow cells. This report describes the first case treated with the combination of off-pump CABG and cell transplantation for therapeutic angiogenesis and myocardial regeneration. The transplantation of autologous bone marrow-derived CD34 + cells improved perfusion of the ungraftable ischemic area.

Bone Marrow Cells↗

PubMed2004

Skeletonized radial artery graft with the St. Jude Medical Symmetry Bypass System (aortic connector system).

BACKGROUND: We report our initial experience with an automatic anastomotic device using skeletonized radial artery in patients requiring off-pump coronary artery bypass grafting (CABG). METHODS: St. Jude Medical, Inc, Symmetry Bypass System (aortic connector system [ACS]) (St Jude Medical, St. Paul, MN) was used in ten patients. Ten consecutive patients who underwent off-pump CABG and who received at least one radial artery graft proximal anastomosis using the ACS were evaluated. The radial artery (RA) was harvested in a skeletonized fashion and applied to the ACS in the same manner as applying saphenous vein graft. The creation of the anastomosis lasted no longer than a few seconds. RESULTS: Our attempt to use the ACS for proximal anastomosis of the RA was successful in all ten patients. Mean operating time was 3.2 +/- 0.6 minutes and an average of 3.0 +/- 0.9 bypass grafts (range, 2 to 5 grafts) were performed. There was no postoperative fatal complication. Postoperative angiographic control showed that all grafts were widely patent including grafts other than the RA. During the mean postoperative follow-up of 10.3 +/- 2.9 months, there was no cardiac-related event in any patient. CONCLUSIONS: The St. Jude Medical Symmetry aortic connector system allows the construction of uniform and widely patent anastomoses in RA graft and does not require aortic side biting. Skeletonization of the RA is a safe and effective technique for applying ACS in off-pump CABG using multiple arterial grafts.

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PubMed2004

Skeletonization of gastroepiploic artery graft in off-pump coronary artery bypass grafting: early clinical and angiographic assessment.

BACKGROUND: Recently skeletonization has been recognized as an alternative to pedicle harvesting of the internal thoracic artery as a technique that increases the length and caliber size of the graft compared with pedicled internal thoracic artery grafts; however, this is not yet popular for harvesting the gastroepiploic artery (GEA). We report here our experience of skeletonized GEA grafting in off-pump coronary artery bypass grafting with early clinical and angiographic results. The purpose of this study was to evaluate skeletonization of GEA grafting in off-pump coronary artery bypass grafting with a large patient volume. METHODS: One hundred sixty-eight patients including 131 men and 37 women (mean age, 65 years; range, 45 to 87 years) underwent the skeletonized GEA grafting in off-pump coronary artery bypass grafting. These patients represent 41% (168 of 407 patients) of those who underwent off-pump coronary artery bypass grafting operations during the same period. We used the GEA graft of choice in patients with right coronary artery lesion. Skeletonization was performed in a unique manner we developed. RESULTS: There were no in-hospital deaths among the study patients. One patient had a perioperative myocardial infarction, which was considered a result of vasospasm of the GEA graft. None of the other patients had severe morbidity. The patency rate of the skeletonized GEA graft was 98.1% (151 of 154 distal anastomoses). CONCLUSIONS: This study suggests that skeletonization of the GEA graft can enlarge its caliber size and improve its flow capacity. In addition, the acceptable early clinical and angiographic outcome suggests that use of the skeletonized GEA graft in off-pump coronary artery bypass grafting surgery is safe and effective.

Aged↗

PubMed2004

Efficacy of FK633, an ultra-short acting glycoprotein IIb/IIIa antagonist on platelet preservation during and after cardiopulmonary bypass.

OBJECTIVE: Temporary pharmacologic inhibition of platelet function during and after cardiopulmonary bypass (CPB) (platelet anesthesia) is an attractive strategy for preserving platelets during CPB. We examined the efficacy of FK633, an ultra-short acting glycoprotein IIb/IIIa antagonist. METHODS: The study was carried out in six mongrel dogs that received an intravenous bolus of 0.1 mg/kg of FK633 at the time of administration of heparin (group F), and six control dogs (group C). All animals underwent 60 min of normothermic CPB followed by a 2-h observation period. Blood samples for platelet count, platelet aggregation to adenosine diphosphate and parameters concerning the coagulation system were obtained at eight time points. Hemodynamics, bleeding time, and postoperative blood loss were assessed serially. Scanning electron micrograph of the oxygenator's membrane was investigated. RESULTS: FK633 significantly protected platelet number (group F, 59+/-10% versus group C, 38+/-15% of the pre-CPB value; P < 0.01), and inhibited platelet aggregation to adenosine diphosphate (group F, 13+/-12% versus group C, 35+/-9% of the pre-CPB value; P < 0.01) during CPB. Postoperative blood loss did not significantly differ between the two groups, but there was a tendency of less bleeding in group F (group F, 73+/-23 ml versus group C, 111+/-44 ml; P = 0.09). In group F, scanning electron micrograph of the oxygenator's membrane showed that its surface was free from platelets. There were no significant differences between the groups in hemodynamics. CONCLUSIONS: An ultra-short acting glycoprotein IIb/IIIa antagonist, FK633, is effective in preventing both platelet aggregation and thrombocytopenia during CPB, and may be effective for minimizing postoperative bleeding.

Adenosine Diphosphate↗

PubMed2004

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

BACKGROUND: Total 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. METHODS: From 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. RESULTS: There 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). CONCLUSIONS: A 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.

Aged↗

PubMed2003

Protective effect of basic fibroblast growth factor against myocyte death and arrhythmias in acute myocardial infarction in rats.

The present study in rats investigated whether basic fibroblast growth factor (bFGF) plays an important role in cardioprotection against myocardial cell death and arrhythmias in acute myocardial infarction (AMI). After ligating the left coronary artery in 62 Wistar rats, 20 Eg of human recombinant bFGF was injected into the infarcted myocardium in 33 rats (group F), while saline was used for 29 control rats (group C). The development of ventricular tachyarrhythmias was assessed during the first 30 min of ischemia. After 24 h occlusion, the hearts of the surviving rats (group F: n=13, group C: n=10) were excised to assess minimum infarct wall thickness and infarct size, determine the number of TUNEL-positive cardiomyocytes and to analyze Bcl-2 and Bax expression by immunohistochemical staining and Western blotting. The incidence of ventricular tachycardia was higher in group C than in group F (p<0.05). The thinning ratio was higher in group F than in group C (p<0.05). There were fewer TUNEL-positive cardiomyocytes in the infarct border area in group F than in group C (p<.0001). Western blot analysis showed greater expression of Bcl-2 in group F than in group C (p<0.05), but similar expression of Bax in the 2 groups. In conclusion, intramyocardial administration of bFGF prevented ischemia-induced myocardial cell death and arrhythmias.

Animals↗

PubMedDate not supplied

Surgical treatment of congenital coronary artery fistulas: 27 years' experience and a review of the literature.

BACKGROUND AND AIM OF THE STUDY: A congenital coronary artery fistula (CAF) is a relatively rare congenital anomaly and is defined as an abnormal direct communication between any coronary artery and any of the cardiac chambers. This article reviews our experience over the past 27 years, as well as other literature, and discusses the surgical indications and methods relating to CAF. METHODS: From 1973, 25 patients aged from 2 to 69 years underwent surgical treatment for congenital CAF. Seventeen patients were diagnosed as isolated CAF. All patients under 19 years of age with isolated CAF were asymptomatic. Twenty fistulas originated from the left coronary artery and 9 from the right. The pulmonary artery was the most dominant drainage site. Four patients among the isolated CAF cases were surgically treated without a cardiopulmonary bypass. RESULTS: All patients were discharged from hospital without any perioperative complications. Postoperative coronary angiography was done on all patients with only one slightly residual CAF flow. The average follow-up time was 9.6 years and all patients were asymptomatic and doing well. CONCLUSIONS: Definitive surgical correction is safe and effective, with good results. Therefore, it should be considered even in asymptomatic patients because of the risk of future complications.

Adult↗

PubMedDate not supplied

An experimental study of a new pull-through technique for aortic arch aneurysm in a porcine model.

A new pull-through technique for placement of the aortic arch stent-graft was developed. Self-expandable curved stents (Matsui-Kitamura stents) were used on 4 pigs. With use of the endoscopic system, the sheath insertion was performed at the ascending aorta. By this pull-through method from the ascending aorta to the femoral artery, the stent was deployed into the aortic arch. All stents were successfully deployed into the correct position, and they fitted into the curvature of the aortic arch wall. By this method, stent-grafting for aortic arch aneurysm is expected to be performed with more accuracy and safety.

Animals↗