[show abstract][hide abstract] ABSTRACT: Adult patients with atrial septal defect frequently experience atrial fibrillation. However, the electrophysiologic mechanism has not been directly examined, and the optimal surgical procedure has not been determined.
Ten patients undergoing operations for atrial septal defect and atrial fibrillation underwent intraoperative mapping by use of 253 epicardial electrodes. There were 7 men and 3 women, whose average age was 54 ± 11 years. Eight patients had a secundum defect and 2 a primum defect. There were 4 patients with paroxysmal atrial fibrillation and 6 with long-standing persistent atrial fibrillation. A modified biatrial Maze procedure was performed in 6 patients and pulmonary vein isolation with no other left atrial lesions in 4.
The reentrant or focal activations driving atrial fibrillation were confined within the right atrium in all patients with paroxysmal atrial fibrillation, whereas multiple focal activations arising from the pulmonary veins or posterior left atrium and reentrant activations in the left atrium were observed in 5 of 6 patients with long-standing persistent atrial fibrillation. In 9 patients, sinus rhythm was restored postoperatively and 8 of those patients have been free of any atrial fibrillation during a follow-up period of 94 ± 45 months.
The pattern of the atrial activation during atrial fibrillation correlated with the type of atrial fibrillation and varied from a simple right atrial reentry to complex reentrant and focal activations in the left atrium.
The Annals of thoracic surgery 08/2013; 96(4):1266-1272. · 3.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Volume-rendering computed tomography (CT) without contrast medium has clearly demonstrated the 3-D mapping of the saphenous vein (SV). Contrastless volume-rendering CT was used to preoperatively evaluate the SV anatomy before coronary artery bypass grafting (CABG). This technique was useful for atypical anatomical variations, such as partial duplication of SV (Case 1) or varicose veins (Case 2). Volume-rendering CT may also help with redo CABG (to determine remaining SV) or during endoscopic SV harvesting with restricted view. Volume-rendering CT is an objective, less time-consuming modality to evaluate the SV preoperatively and may be less invasive in terms of avoiding unnecessary skin incision.
Interactive cardiovascular and thoracic surgery 01/2013;
[show abstract][hide abstract] ABSTRACT: "Depolarized arrest", induced by hyperkalemic (moderately increased extracellular potassium) cardioplegia is the gold standard to achieve elective temporary cardiac arrest in cardiac surgery. Hyperkalemic cardioplegic solutions provide good myocardial protection, which is relatively safe and easily and rapidly reversible. However, this technique has detrimental effects associated with ionic imbalance involving sodium and calcium overload of the cardiac cell induced by depolarization of the cell membrane. Hence, the development of an improved cardioplegic solution that enhances myocardial protection would be expected as an alternative to hyperkalemic cardioplegia. In this review, we assess the potential disadvantages of "depolarized arrest" and the suitability and clinical potential of "non-depolarized arrest". "Magnesium cardioplegia" and "esmolol cardioplegia" has been shown to exert superior protection with comparable safety profiles to that of hyperkalemic cardioplegia. These alternative techniques require further examination and investigation to challenge the traditional view that hyperkalemic arrest is best. Endogenous cardioprotective strategies, termed "ischemic preconditioning" and "ischemic postconditioning", may have a role in cardiac surgery to provide additional protection. The elective nature of cardiac surgery, with the known onset of ischemia and reperfusion, lends it to the potential of these strategies. However, the benefit of preconditioning and postconditioning during cardiac surgery is controversial, particularly in the context of cardioplegia. The clinical application of these strategies is unlikely to become routine during cardiac surgery because of the necessity for repeated aortic crossclamping with consequent potential for embolic events, but offers considerable potential especially if "pharmacological" preconditioning and postconditioning could be established.
Journal of Nippon Medical School 01/2013; 80(5):328-41.
[show abstract][hide abstract] ABSTRACT: Since its introduction in the early 1970s, coronary artery bypass grafting (CABG) has become an established surgical treatment for coronary artery disease (CAD). Percutaneous coronary intervention (PCI), first clinically applied in 1977, was promoted as an alternative to CABG during the mid-1980s. Along with the nationwide expansion of PCI, the ratio of PCI to CABG has exceeded 6-7:1. The Japanese Circulation Society (JCS) published "Guidelines on elective coronary intervention, including coronary artery bypass grafting (CABG), for ischemic heart disease in 2000" and "Guidelines on the selection of bypass conduits and operative procedures in coronary artery bypass grafting for ischemic heart disease". The society intended to revise these guidelines in 2010 and to issue two new guidelines specific either to PCI or CABG. They also planned to issue joint guidelines for myocardial revascularization and PCI/CABG, which are primary indications for patients with stable CAD, especially with those with more complex left main trunk disease and/or multi-vessel disease. The scientific committee of JCS established the "Council for myocardial revascularization" that consisted of experts including interventional and non-interventional cardiologists, cardiac surgeons and physicians specialized in diabetes or nephrology selected by medical and surgical societies. After over 10 rounds of meetings, the Council prepared primary guidelines for myocardial revascularization to treat stable CAD, PCI/CABG. These guidelines consist of (1) Statements about myocardial revascularization, (2) Interpretation of the statements and (3) Indications for PCI/CABG including a table.
General Thoracic and Cardiovascular Surgery 12/2012;
[show abstract][hide abstract] ABSTRACT: An infected aortic arch aneurysm is a rare but life-threatening condition. Moreover, surgical treatment for patients with severe calcified aorta is challenging and needs a well-planned strategy. We report a patient with an infected aortic arch aneurysm concomitant with severe calcification of the aorta in whom good results were obtained with open stent grafting in combination with a trifurcated graft.
Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 11/2012;
[show abstract][hide abstract] ABSTRACT: Double potential mapping using bipolar electrodes that straddle the ablation line should identify the site of incomplete ablation as a conduction gap without constructing the activation maps.
Bipolar electrograms were recorded during pacing using 11 custom-made bipolar electrodes straddling the ablation line created by a bipolar radiofrequency ablation device on the lateral right atrium in seven canines. A linear ablation was made with an ablation device, of which one jaw was inserted into the atrium through a purse-string suture. A 3-mm-wide tape was placed on both jaws 10 mm from the tip of the ablation electrode to intentionally create an incomplete ablation lesion. The activation times at each dipole across the ablation line were defined as the times of the maximum positive and negative derivatives of the double potentials, and the site of conduction gap was determined as the site of the earliest activation across the linear ablation. The lateral right atrium was mapped simultaneously with 45 different bipolar electrodes to construct the activation maps and the earliest activation site across the ablation line was determined.
The double potential mapping located the conduction gap on a real-time basis without displaying any maps. There was no significant change in the accuracy between the different times after ablation and different pacing cycle lengths.
Double potential mapping locates the conduction gap on a real-time basis and would be useful in beating-heart epicardial ablation in off-pump setting.
Innovations Technology and Techniques in Cardiothoracic and Vascular Surgery 11/2012; 7(6):429-34.
[show abstract][hide abstract] ABSTRACT: The patient was a 29-year-old male who had been diagnosed with transposition of the great arteries with an intact ventricular septum. At the age of 6 months, he underwent a Senning operation. At the age of 10 years, a dual-chamber (DDD) pacemaker was implanted via the right subclavian vein for the treatment of sick sinus syndrome. At the age of 25, the generator was removed due to a lead fracture, and a new pacemaker was implanted via the left subclavian vein, leaving the previous lead in the right subclavian vein. Later, the patient developed pain in the right precordium, cramping of the major pectoral muscle, and non-sustained ventricular tachycardia, suggesting physical stimulation of the left ventricle (functional right ventricle) by the residual leads. Therefore, lead extraction using an excimer laser sheath was planned. However, the leads adhered strongly to the vessels, and extraction was considered to involve a high risk of injury to the blood vessels, particularly the superior vena cava (SVC). We inserted a thoracoscope via the right precordial third intercostal space and observed the SVC via the thoracic cavity in order to immediately detect any complications. Using this approach, it was possible to extract the lead safely with an excimer laser sheath.
[show abstract][hide abstract] ABSTRACT: We present two cases with an occluded left subclavian artery requiring coronary artery bypass grafting. A preoperative angiogram
confirmed that the subclavian artery, including the internal thoracic artery distal from the occlusion, was thoroughly intact,
in both cases. Immediately after reconstructing the subclavian artery using an aortoaxillary bypass with an 8 mm ring-reinforced
polytetrafluoroethylene graft, each patient underwent double coronary artery bypass grafting using the affected left internal
thoracic artery with either the right internal thoracic artery or a saphenous vein in the same anesthetic setting. Symptomatic
relief was excellent In both cases, a postoperative angiographic study showed good function of the left internal thoracic
artery graft supplying blood to the coronary artery through the aortoaxillary bypass graft.
Key wordssubclavian artery occlusion–internal thoracic artery–CABG
The Japanese Journal of Thoracic and Cardiovascular Surgery 04/2012; 48(8):524-527.
[show abstract][hide abstract] ABSTRACT: An electroanatomic mapping system using an electromagnetic navigation technology constructs a 3-dimensional structure of the heart with high geometric accuracy of the data that provides a precise localization of the substrates of arrhythmias. The system was tested for the feasibility and efficacy in intraoperative mapping.
The strength of the magnetic field is measured by a location sensor with three different frequencies generated by a location pad placed beneath the operating table, and the spatial location of the sensor is determined. By roving the catheter on the heart while the local electrogram is recorded simultaneously, the 3-dimensional figure of the heart is reconstructed and an activation or voltage map is generated.
The system was used in 19 patients with ventricular tachycardia or other arrhythmias. The focus or reentrant circuit of the tachycardia was precisely located and a map-guided procedure was successfully performed in all patients. Cardiopulmonary bypass allowed for the tachycardias to be mapped without any hemodynamic compromise.
Intraoperative mapping using the electroanatomic mapping system enables a precise localization of the tachycardia substrate.
The Annals of thoracic surgery 04/2012; 93(4):1285-8. · 3.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Standard surgical methods for managing true aneurysms of the deep femoral artery have not been established because these aneurysms are rare. An 85-year-old man, who had a ruptured aneurysm of the deep femoral artery, underwent aneurysmectomy and distal reconstruction with a contralateral autologous vein graft. Three-dimensional computed tomography is a valuable diagnostic modality to evaluate synchronous aneurysms and peripheral arterial circulation for treatment planning. Because of their etiology, aneurysms of the deep femoral artery should be treated with revascularization when technically feasible, even if the superficial femoral artery is patent. A contralateral saphenous vein may be the preferred conduit because ipsilateral venous stasis is likely.
Journal of Nippon Medical School 01/2012; 79(5):377-80.
[show abstract][hide abstract] ABSTRACT: This study investigated the relation between the cause of blunt cardiac injury and areas of damage. For the purpose of injury prevention, we also examined traffic accident cases in a micro study using engineering-based medicine.
Among the 2673 patients transported to our facility within the 15-month period from February 2009 to April 2010, there were 12 cases of cardiac perforation. We studied these cases anatomically to evaluate the morphology of the damaged cardiac areas. We conducted a detailed micro-study in two cases regarding the circumstances surrounding the traffic accident and the vehicular damage.
Subjects were nine men (mean age 64 years). The mean Injury Severity Score was 54.0 ± 19.6, and the probability of survival was 0.147. The actual survival rate was 16.7% (2 survivors, 10 deaths). Lesion sites in the 12 cases (21 sites in total) were the right atrium in 8 cases, superior and inferior vena cava in 5 cases, right ventricle in 4 cases, pulmonary artery and left atrium in 1 case each, and pulmonary vein in 2 cases, excluding the left ventricle and ascending aorta. In three cases, the aortic isthmus was also injured.
Blunt cardiac injury was more common on the right side chamber. The survival rate was extremely close to the calculated survival probability. Proper seatbelt usage is important for the prevention of blunt cardiac injury due to traffic accidents. Increased severity of injury may be associated with accidents involving light motor vehicles.
General Thoracic and Cardiovascular Surgery 01/2012; 60(1):31-5.
[show abstract][hide abstract] ABSTRACT: Platelet-rich plasma (PRP) contains numerous growth factors that have angiogenic activities. However, the PRP-induced angiogenesis is limited by the short half-life period of growth factors. A new drug delivery system of biodegradable gelatin hydrogel was designed to achieve the controlled release of growth factors in PRP. The purpose of this study is to demonstrate the therapeutic efficacy of slow-release of PRP in the inducing of angiogenesis for critical ischemia.
The PRP was prepared from the whole blood of inbred rats. Thirty-two rats underwent excision of the left femoral artery and its branches to create critical limb ischemia. The rats were randomized into four groups (n=8 each): no treatment (control), intramuscular injection of platelet-poor plasma (PPP), PRP only, or a combination of PRP and gelatin hydrogel (PRP+Gel). Four weeks after the treatment, angiogenesis was evaluated by laser doppler, microangiogram, and immunohistology.
The resultant number of platelets for PRP was higher than that of PPP (p<0.01). The concentrations of vascular endothelial growth factor, transforming growth factor-β1, and platelet-derived growth factor-BB were significantly higher in PRP animals than in PPP (p<0.01). Although the PRP group improved tissue blood flow (82.7%±6.2%) compared with the control group or PPP group (69.6±12.2 or 72.2±11.8%, p<0.05), the improvement of blood flow in the PRP+Gel group was significantly better (95.1%±8.0%, p<0.05) than in the PRP group. Angiographic score in the PRP+Gel group was significantly higher than that in the control, PPP, and PRP groups (8.6±2.1 versus 3.8±0.8, 3.7±0.6, and 5.6±1.5, respectively; p<0.01). Capillary density also increased immunohistologically in the PRP+Gel group when compared with the control, PPP, and PRP groups (p<0.01).
A controlled release system of PRP was effective in inducing angiogenesis for critical ischemia. The biodegradable gelatin hydrogel incorporating PRP as applicable could possibly be used to treat for patients with ischemic cardiomyopathy.
The Annals of thoracic surgery 09/2011; 92(3):837-44; discussion 844. · 3.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Deep vein thrombosis (DVT) is a major risk factor for pulmonary thromboembolism (PTE). We carefully selected patients for surgical thrombectomy to treat acute-phase thrombosis and obtained favorable results.
Over the past 5 years, we have performed surgical thrombectomy via a minimum femoral skin incision in 11 patients. Surgery was considered for patients with persistent phlegmasia cerulea dolens, despite thrombolytic therapy. All of our patients underwent surgery within 14 days of the onset of symptoms. During the operation, the patients were kept in the supine anti-Trendelenburg position to prevent PTE, and general anesthesia was maintained with positive-pressure mechanical ventilation. Blood flow to the inferior vena cava was occluded with a blocking catheter, and thrombectomy was performed with a thrombectomy catheter inserted parallel to the blocking catheter. A cell separator device was used effectively for autologous blood transfusion. To prevent reocclusion and promote collateral perfusion, we constructed an arteriovenous fistula for an iliac venous spur.
There were no major postoperative complications, such as PTE or peritoneal bleeding, and no cases of postthrombotic syndrome after an average 38.4 months of follow-up.
This surgical technique for venous thrombectomy is minimally invasive and safe for Japanese patients; surgical thrombectomy should be considered a treatment option for DVT in Japan.
Journal of Nippon Medical School 06/2010; 77(3):155-9.
[show abstract][hide abstract] ABSTRACT: Cardiopulmonary bypass (CPB) has been implicated as a cause of acute lung injury (ALI) in cardiac surgical patients. We used a bronchoscopic microsampling (BMS) probe to examine alveolar biochemical constituents and evaluated the effect of sivelestat sodium hydrate, a novel synthesized polymorphonuclear (PMN) neutrophil elastase inhibitor, on ALI induced by CPB. Twelve patients undergoing aortic valve replacement were treated with either sivelestat 0.2 mg/kg/h (sivelestat group, n=6) or 0.9% saline (control group, n=6) from the start of surgery. Samples were collected by the BMS probe at three time points: after tracheal intubation, 1 h after CPB introduction, and 3 h after CPB termination. Pulmonary function was assessed perioperatively. There were no differences in baseline characteristics. The concentration of PMN elastase was significantly suppressed in the sivelestat group, compared with the control group (P=0.001). The sivelestat group also had lower levels of interleukin-6 and interleukin-8. Alveolar-arterial oxygen difference markedly increased, and a worsening of the PaO(2)/FiO(2) ratio indicated severe impairment after CPB. However, sivelestat attenuated the pattern of physiological deterioration of gas exchange. Sivelestat may attenuate neutrophil elastase or proinflammatory cytokines, and improve pulmonary dysfunction in patients undergoing CPB.
Interactive cardiovascular and thoracic surgery 03/2010; 10(6):859-62.
[show abstract][hide abstract] ABSTRACT: We experienced an unusual case of partial atrioventricular septal defect in an elderly patient. A preoperative ultrasonic cardiogram revealed the mitral leaflet pouching toward the right atrium and suggested the presence of a ventricular septal defect underneath the atrioventricular valve. The mitral aneurysm was diagnosed as a septal aneurysm on preoperative ultrasonic cardiogram. A crescent-shaped Dacron patch (InterVascular S. A., La Ciotat Cedex, France) was placed beneath the atrioventricular valve to prevent rupture of the mitral aneurysm and support the anterior mitral leaflet by creating a new annulus. We believe that this is the first report describing this type of mitral aneurysm and its surgical repair.
The Annals of thoracic surgery 10/2009; 88(4):1341-3. · 3.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pulmonary dysfunction is a frequent postoperative complication after cardiac surgery with cardiopulmonary bypass, and atelectasis is thought to be one of the main causes. The aim of this study was to evaluate whether low-frequency ventilation and continuous positive airway pressure during cardiopulmonary bypass reduce postcardiopulmonary bypass lung injury.
Eighteen Yorkshire pigs were subjected to 120 minutes of cardiopulmonary bypass (1 hour of cardioplegic arrest) followed by 90 minutes of recovery before being sacrificed. Six animals served as control with the endotracheal tube open to atmosphere during cardiopulmonary bypass. The remaining animals were divided into 2 groups of 6: One group received continuous positive airway pressure of 5 cm H(2)O, and one group received low-frequency ventilation (5/minutes) during cardiopulmonary bypass. Lung tissue biopsy and bronchoalveolar lavage samples were obtained before and 90 minutes after discontinuation of cardiopulmonary bypass for measurement of adenine nucleotide (adenosine-5'-triphosphate, adenosine diphosphate, adenosine monophosphate), lactate dehydrogenase, DNA levels, and histology. Hemodynamic data and arterial blood gases were also collected through the study.
The hemodynamic parameters were similar in the 3 groups. After cardiopulmonary bypass, the low-frequency ventilation group showed significantly better oxygen tension and alveolar arterial oxygen gradient, higher adenine nucleotide, lower lactate dehydrogenase levels, and reduced histologic damage in lung biopsy, as well as lower DNA levels in bronchoalveolar lavage compared with the control group. The continuous positive airway pressure group showed only significantly reduced lactate dehydrogenase levels compared with control.
Low-frequency ventilation during cardiopulmonary bypass in a pig experimental model reduces tissue metabolic and histologic damage in the lungs and is associated with improved postoperative gas exchange.
The Journal of thoracic and cardiovascular surgery 07/2009; 137(6):1530-7. · 3.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Sivelestat, a neutrophil elastase inhibitor, has been shown to attenuate pulmonary injury during ischemia and reperfusion by improving microcirculation and may be effective as a cardioprotective agent. Isolated rat hearts were Langendorff-perfused (constant pressure, 75 mmHg) with oxygenated Krebs-Henseleit bicarbonate buffer (KHB). The optimal sivelestat concentration at 19 micromol/l was revealed because left ventricular developed pressure (LVDP) recovery in 19 micromol/l sivelestat was highest among 0.19, 1.9, 19, 190, and 1900 micromol/l sivelestat (26+/-10, 33+/-7, 56+/-5*, 35+/-2, and 15+/-5%, respectively; *P<0.01). In order to examine the optimal administration timing, sivelestat was administered at pre- and post-ischemic phases. LVDP recovery and troponin-T were observed in pre-, post-ischemic sivelestat groups and control. After 60 min-reperfusion, LVDP recoveries were 42+/-10*, 45+/-19*, and 14+/-5%, respectively (*P<0.01 compared to control), and troponin-T values were 4+/-1, 2+/-1**, and 8+/-2, respectively (**P<0.05 compared to control). Acetylcholine-induced increase in coronary flow was also investigated to examine the sivelestat's cardioprotective mechanism. Ischemia-reperfusion (I/R) impaired the acetylcholine-induced increase in coronary flow (maximal changes: sham, 125+/-11%; I/R, 98+/-3; P<0.01) and this impairment was attenuated by sivelestat-perfusion at reperfusion (maximal change: 112+/-7%; P<0.05 vs. I/R). Sivelestat attenuates coronary endothelial ischemia-reperfusion injury and improves myocardial protection even when administered at the reperfusion period. This suggests a role for sivelestat in the preservation of coronary endothelial function enhancing myocardial protection.
Interactive cardiovascular and thoracic surgery 03/2009; 8(6):629-34.