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Biomedical subjects

Shigeyuki Tomita

Publications and source records attributed to Shigeyuki Tomita.

At least 19 recordsLinked to original sources
PubMed2006

Portable coronary active perfusion system for off-pump coronary artery bypass grafting.

PURPOSE: The present study was performed to develop a new perfusion system for off-pump coronary artery bypass grafting and to examine whether even a simple coronary perfusion system can maintain adequate blood flow delivery during anastomosis. DESCRIPTION: The experiment was performed in two stages. In procedure 1, 3 pigs with left anterior descending artery occlusion were used to evaluate optimal perfusion flow rate and coronary artery internal pressure, and to evaluate the safety area of perfusion. In procedure 2, 6 pigs were used to validate the new portable coronary perfusion system. EVALUATION: The optimal blood flow in the portable coronary active perfusion system was less than approximately 40 mL/min. The small, easy to use pump system (ie, the portable coronary active perfusion system) may prevent hemodynamic deterioration and ventricular arrhythmia during coronary occlusion, resulting in better maintenance of left ventricular function. CONCLUSIONS: Even a simple pump system can achieve effective perfusion for safe anastomosis. Further studies are required to allow the clinical use of this system.

Anastomosis, Surgical↗
PubMed2006

Successful coronary revascularization using the PAS-Port system in a patient with Takayasu's arteritis and Behcet's disease.

Coronary artery disease is rare in patients with Takayasu's arteritis or Behcet's disease. We report the case of a patient with concomitant Takayasu's arteritis and Behcet's disease who had angina pectoris develop due to severe narrowing of the left main coronary artery. The patient underwent revascularization with saphenous vein grafts with the assistance of the PAS-Port Proximal Anastomosis System (Cardica, Inc, Redwood City, CA). In conclusion, the PAS-Port Proximal Anastomosis System seems to be a safe and effective method of facilitating revascularization, particularly when severe calcification of the ascending aorta precludes cross-clamping during off-pump coronary artery bypass grafting.

Anastomosis, Surgical↗
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↗
PubMed2006

[Endoscopic off-pump coronary artery bypass].

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.

Coronary Artery Bypass, Off-Pump↗
PubMed2005

Intramyocardial foreign body: sewing needle with the uncommon clinical feature of constrictive pericarditis.

A rare case of intracardiac injury with a sewing needle causing constrictive pericarditis is reported. A 72-year-old woman was admitted with edema of the face and legs. A chest radiogram showed a needle-shaped metallic image overlying the cardiac silhouette. Computed tomography revealed the needle was located in the left ventricular myocardium, and also showed a thickened pericardium. Surgical removal of the needle and pericardectomy were performed simultaneously.

Aged↗
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↗
PubMed2005

A multipurpose arterial graft holder for coronary artery bypass grafting.

A multipurpose arterial graft holder designed for use during coronary artery bypass grafting is described. This new holder is atraumatic and holds the arterial grafts and saphenous vein graft securely during anastomosis. The use of this instrument facilitates the use of multiple arterial grafts for coronary artery bypass grafting.

Arteries↗
PubMed2005

A novel figure A-shape sternal retractor for off-pump coronary artery bypass grafting.

A novel figure A-shape sternal retractor was developed to avoid brachial plexus injury caused by sternal wide separation, and facilitate exposure of circumflex artery by elevating a rake and dropping the heart into the right pleural cavity during off-pump coronary artery bypass grafting. In addition, it has several notches to hold deep pericardial stitches in order to enhance the exposure.

Brachial Plexus↗
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.

Aged↗
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

Beating heart coronary artery bypass grafting: results from 402 patients and the usefulness of gastroepiploic artery composite grafting.

OBJECTIVES: We have studied the results of 402 consecutive cases of beating heart coronary artery bypass grafting (CABG) and evaluated the usefulness of gastroepiploic artery (GEA) composite grafts. METHODS: Between March 1993 and August 2001, 402 patients underwent beating heart CABG. They were 321 male and 81 female patients, aged 17 to 88 (mean 66) years. Beating heart CABG was facilitated by mechanical stabilization with a doughnut stabilizer, a newly designed sternal retractor and a new coronary perfusion system. Minimally invasive direct coronary artery bypass (MIDCAB) was performed in 206 patients (the MIDCAB Group), and beating heart CABG with median sternotomy (OPCAB) was performed in 196 patients (the OPCAB Group). RESULTS: Definite off-pump CABG was accomplished in 381 patients. 21 patients (5%) were converted to on-pump beating heart CABG using percutaneous cardiopulmonary system via femoral vessels because of hemodynamic instability. There was 1 operative mortality (0.2%). There was perioperative myocardial infarction in 2 (0.5%), and cerebral infarction in 3 (0.7%). The rate of complete revascularization was 78% in the MIDCAB Group and 97% in the OPCAB Group. The mean number of anastomoses was 1.6 in the MIDCAB Group and 3.3 in the OPCAB Group. The early graft patency was 99.1% in a left internal thoracic artery graft, 97.0% in a right internal thoracic artery graft, 96.5% in GEA, 98.2% in a radial artery graft, and 94.2% in a vein graft. A GEA composite graft was used in 55 of the 168 patients who received GEA grafting. The mean number of anastomoses for the GEA composite graft was 1.6 +/- 0.6 per patient. The graft patency rate was 94.6% (53/56) for GEA and 98.6% (72/73) for the radial artery used as a composite graft. CONCLUSION: A consecutive series of beating heart CABG was performed safely and effectively with a low mortality rate and low morbidity rate. Beating heart CABG could be performed in all patients, and definite off-pump CABG was accomplished in 95% of them. In order to aim for complete revascularization, GEA composite graft was found to be effective since it required a low mean number of 1.6 anastomoses and a satisfactory patency rate at the same time.

Adolescent↗
PubMed2003

Aortic valve replacement by limited sternotomy for infective endocarditis in a patient with a tracheostomy.

Active infection in the area of the tracheostomy during cardiac surgery presents a high risk. We successfully performed urgent aortic valve replacement for an endocarditis patient with active infection of methicillin resistance staphylococcus aureus in the tracheostoma. To avoid wound infection, a 2nd J-limited sternotomy was used during the operation. Despite malnutrition, the patient showed no wound infection after surgery and recovered smoothly.

Aged↗