Hiroshi Nagamine

Surgical Treatment of Congenital Coronary Artery Fistulas: 27 Years' Experience and a Review of the Literature

Abstract 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.

Therapeutic angiogenesis with intramyocardial administration of basic fibroblast growth factor

BACKGROUND Basic fibroblast growth factor (bFGF) induces endothelial cell and smooth muscle cell proliferation and stimulates angiogenesis. This study was designed to evaluate the effects of intramyocardial administration of bFGF on myocardial blood flow, angiogenesis, and ventricular function in a canine acute infarction model. METHODS Myocardial infarction was induced in 12 dogs by ligation of the left anterior descending coronary artery. Within 5 minutes after coronary occlusion, 100 microg of human recombinant bFGF in 1 mL of saline was injected into the infarct and border zone in 6 dogs, whereas saline alone was used in 6 control dogs. Myocardial blood flow was determined with colored microspheres before and immediately after coronary ligation and again 3, 7, 14, and 28 days after treatment and it was expressed as percent of normal. Angiogenesis was evaluated by immunohistochemical studies 28 days later. Cardiac function was evaluated by repeated echocardiographic measurement. RESULTS Treatment with bFGF significantly increased the endocardial blood flow in the border zone (7 days after infarction, 75%+/-7% and 41% +/-7% in the bFGF and control groups, respectively, p<0.01) as well as epicardial blood flow in the infarcted zone. Treatment with bFGF significantly increased the capillary density (39.7+/-2.3 and 22.7+/-1.1 vessels per visual field in the bFGF and control groups, respectively, p<0.01) as well as arteriolar density in the border zone. Treatment with bFGF significantly reduced the change in ratio of thickness of the infarcted wall to the normal wall (44%+/-6% and 26% +/-5% in the bFGF and control groups, respectively, p<0.05). It improved the left ventricular ejection fraction (7 days after infarction, 0.54+/-0.02 and 0.37+/-0.03 in the bFGF and control groups, respectively, p<0.01). CONCLUSIONS Intramyocardial administration of bFGF increased the regional myocardial blood flow, reduced thinning of the infarcted region, and improved ventricular function in acute myocardial infarction. Intramyocardial administration of bFGF may be a new therapeutic approach for patients with acute myocardial infarction.

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.

A new classification system for branch artery perfusion patterns in acute aortic dissection for examining the effects of central aortic repair

OBJECTIVES We developed a new classification system for branch perfusion patterns in acute aortic dissection and used it to retrospectively evaluate the perfusion status of whole aortic branches and to examine the effects of central aortic repair. METHODS Thirty-four consecutive patients with acute type A aortic dissection underwent emergent surgery at our institution between August 2008 and December 2011. A retrospective review of pre- and postoperative computed tomographic angiography was performed. Branch perfusion patterns were categorized into three classes: Class I, dissection involving but not extending into the branch; Class II, dissection extending into the branch and Class III, dissection causing ostial avulsion. RESULTS In cervical branches (total 169 branches), 70 branches (41%) presented with Class I patterns, 58 (34%) with Class II and none with Class III. In abdominal branches (total 135 branches), 76 branches (56%) presented with Class I patterns, 12 (9%) with Class II and 18 (13%) with Class III. In common iliac arteries (total 68 arteries), 14 arteries (21%) presented with Class I patterns, 24 (35%) with Class II and none with Class III. After repair, among 21 high-risk cervical branches, 14 branches (67%) showed improvement, 3 (14%) preserved distal perfusion supplied through the patent branch false lumen and 4 (19%) showed no improvement in high-risk perfusion pattern or worsened. Among 22 high-risk abdominal branches, 18 branches (82%) showed improvement, 3 (14%) preserved distal perfusion supplied through the patent branch or aortic false lumen and 1 (5%) showed no improvement in high-risk perfusion pattern. CONCLUSIONS To overcome malperfusion syndromes associated with acute aortic dissection, recognition of diverse branch perfusion patterns through a universal classification system is imperative.

Left ventricular perforation and dissecting subepicardial hematoma after catheter ablation for Wolff-Parkinson-White syndrome

Radiofrequency catheter ablation of accessory bypass tracts has become a widely accepted therapy for Wolff-Parkinson-White (WPW) syndrome. The procedure typically has a high success rate with a low incidence of complications. Left ventricular perforation is a rare but serious complication of catheter ablation. Here we describe a patient who developed left ventricular perforation and a dissecting subepicardial hematoma with cardiac tamponade following catheter ablation for WPW syndrome. Immediate hematoma evacuation and direct repair of the fragile myocardium were performed under cardiopulmonary bypass, and the patient survived with no further complications.

Japan's first robot-assisted totally endoscopic mitral valve repair with a novel atrial retractor.

This case report presents the first robot-assisted totally endoscopic mitral valve plasty in Japan. A 54-year-old woman was found by echocardiography to have grade III mitral valve regurgitation because of prolapse of the posterior leaflet. Surgical repair was performed using the da Vinci Surgical System. For the totally endoscopic mitral valve repair, a right-sided approach was used through four ports. A transthoracic aortic cross-clamp and novel flexible port access retractor were inserted through a 5-mm skin incision. Quadrangular resection of the posterior leaflet was performed, and an annuloplasty band was placed into the atrium. Resection of the valve segment took 13 min, and band implementation, 45 min. The total pump time was 197 min and the aortic cross-clamp time, 117 min. Postoperative echocardiography confirmed the absence of mitral insufficiency.

Use of skeletonized radial artery graft with the PAS-Port proximal anastomotic device.

Purpose We report our initial experience with the PAS-Port proximal anastomosis system (Cardica Inc, Redwood City, CA) using full-skeletonized radial artery (RA) in patients requiring off-pump coronary artery bypass grafting. Description The PAS-Port system (Cardica Inc) was used in 25 patients undergoing off-pump coronary artery bypass surgery. All patients received at least one RA graft using the PAS-Port system on the proximal anastomosis. The radial arteries were harvested in a fully skeletonized fashion before loading to the PAS-Port system. Evaluation Our attempt to use the PAS-Port system for proximal anastomosis of the RA was successful in 25 anastomoses. Postoperative angiography showed 24 grafts to be widely patent. During the mean postoperative follow-up of 9.2 ± 3.1 months, there was no cardiac-related event in any patient. Mid-term patency collected from the first 8 patients was 87.5% (mean follow-up, 12.8 ± 2.8 months). Conclusions The PAS-Port system does not require aortic clamping and enables the creation of uniform and widely patent anastomosis with use of RA grafts.

Clinical significance of a false lumen pathway through the arch in acute type A aortic dissection and its influence on cervical branch compromise

OBJECTIVES Upon onset of acute type A aortic dissection, the aortic true lumen generally becomes fixed around the supra-aortic branches in the greater curvature and Botallos ligament in the lesser curvature of the aortic arch. Therefore, the pathways of the false lumen through the arch can be categorized as anterior, bilateral and posterior. We investigated the relationship between a false lumen pathway through the arch and cervical branch compromise, stratified by primary tear location. METHODS Sixty-four consecutive patients with acute type A aortic dissection underwent emergency surgery at our institution between March 2005 and October 2013. Of these, 40 cases (63%) were DeBakey type I, 15 cases (23%) were type II and 9 cases (14%) were type III-D (retrograde type A). We conducted a retrospective review of preoperative computed tomographic angiography using three-dimensional image post-processing tools for 43 cases, excluding 15 cases with type II and 6 cases with type I for which preoperative digital image data were not available. RESULTS Of the 43 cases, 14, 18 and 11 revealed anterior, bilateral and posterior pathways, respectively. Twenty-one cases (49%) showed a primary intimal tear in the ascending aorta (8 anterior, 12 bilateral and 1 posterior), 12 cases (28%) showed a primary intimal tear in the aortic arch (5 anterior, 3 bilateral and 4 posterior) and 10 cases (23%) showed a primary intimal tear in the descending aorta (1 anterior, 3 bilateral and 6 posterior). Twelve of the 14 anterior pathway cases (86%) had a total of 26 supra-aortic branch compromises, 13 of the 18 bilateral pathway cases (72%) had a total of 20 supra-aortic branch compromises, while only 4 of the 11 posterior pathway cases (36%) had a total of four supra-aortic branch compromises. None of the 11 posterior pathway cases had a dissection extending into all 3 supra-aortic branches. CONCLUSIONS Posterior pathway cases generally showed primary tear locations in the arch or descending aorta, and cervical branch compromise was rare. Aortic dissections tended to extend into the cervical branches through the anterior side of the aortic arch. A false lumen pathway through the arch was strongly associated with cervical branch compromise in acute type A aortic dissections.

Visualization of myofiber architecture in the left ventricular myocardium: re-evaluation of Lunkenheimer’s pneumo-myocardium technique

Fig. 1. Three-dimensional orthogonal multi-planar reconstruction images of postmortem porcine pneumo-myocardium. In 1984, Lunkenheimer et al. reported a trans-coronary pneumo-myocardium technique to visualize myocardial architecture in Investigative Radiology. Pneumo-myocardium was produced with continuous transcoronary air injection at 600 mmHg. Capillary vessel walls were dissected and myocardial fibers were gently separated. (A) Mid-ventricular slice in the axial plane. (B) Long-axis three-chamber view

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.