Biomedical subjects

Osamu Tagusari

Publications and source records attributed to Osamu Tagusari.

44 records · Page 3Linked to original sources

PubMed2002

The effect of cryo-maze procedure on early and intermediate term outcome in mitral valve disease: case matched study.

BACKGROUND: The maze procedure is an effective way to treat atrial fibrillation (AF) associated with mitral valve disease. In a last several years, cryoablation was substituted for atrial incision in many reports to simplify the maze procedure. However, there has been no comparative study to delineate the feasibility of the use of cryoablation. METHODS AND RESULTS: We compared the early and intermediate-term results of the maze procedure including pulmonary venous isolation from the left atrium using cryoablation (CM) with our conventional (Kosakai) maze procedure (KM) including encircling incision around the orifices of pulmonary veins. One hundred and 10 pairs of patients were matched in the age, left atrial dimension >70 mm, duration of AF >0 years, previous cardiac surgery, mechanical valve implantation and concomitant aortic valve procedures. CM required significantly shorter cardiopulmonary bypass time (186+/-56 minute versus 214+/-47 minute, P=0.001) and aortic cross-clamp time (134+/-43 minute versus 144+/-37 minute, P=0.03) than KM with less chest tube drainage (590+/-353 mL versus 745+/-618 mL, P=0.02) for 12 hours after operation. The sinus rhythm restoration rate in CM group (85.4%) was comparable with KM group (86.4%) at discharge. In the late results, the actuarial freedom from recurrence of sustained AF at 3 years in CM group (97.7%) was not significantly (P=0.11) different from that in KM group (90.4%). The actuarial freedom from stroke at 3 years in CM group was 99.0%. CONCLUSION: The modification of the maze procedure including cryoablation for pulmonary venous isolation provided less aortic cross-clamp time and less amount of chest tube drainage with the comparable recovery and maintenance of sinus rhythm with KM. CM is a reliable and less invasive surgical option for the AF associated with mitral valve disease.

Atrial Fibrillation↗

PubMed2002

The impact of diabetic retinopathy on long-term outcome following coronary artery bypass graft surgery.

OBJECTIVES: We sought to assess the impact of diabetic retinopathy on long-term outcome among patients with diabetes and multivessel coronary artery disease (MVD) following coronary artery bypass graft surgery (CABG). BACKGROUND: For diabetics, CABG is the preferred revascularization strategy. Diabetic retinopathy is a major microvascular complication of diabetes, and its severity is directly related to total glycemic exposure. METHODS: We identified 223 consecutive diabetics with MVD whose retinae were evaluated within one year prior to CABG. The most recent ophthalmologic records up until the time of CABG were used to evaluate the severity of retinopathy. The median follow-up after CABG was 11.6 years. RESULTS: Diabetic retinopathy was a strong independent predictor of overall mortality (relative risk [RR], 4.0), and repeat revascularization (RR, 3.0). In separate analyses of diabetics with retinopathy and without retinopathy, predictors of mortality differed significantly between the two groups. Among diabetics with retinopathy, the presence of either preoperative renal (RR, 2.5) or ventricular (RR, 2.0) dysfunction had unfavorable effects on mortality, but the survival curves did not differ significantly according to the presence or absence of internal thoracic artery (ITA) grafting. In comparison, among diabetics without retinopathy, ITA grafting (RR, 0.34) had a beneficial effect on mortality, and the survival curves varied somewhat according to the presence or absence of renal or ventricular dysfunction. CONCLUSIONS: Diabetics with retinopathy had a distinct post-CABG course with a worse long-term prognosis, as compared with diabetics without retinopathy. Retina evaluation is useful for prediction of long-term prognosis and management of diabetics who need CABG.

Aged↗

PubMed2002

EVAHEART: an implantable centrifugal blood pump for long-term circulatory support.

OBJECTIVE: We developed "EVAHEART": a compact centrifugal blood pump system as an implantable left ventricular assist device for long-term circulatory support. The 55 x 64 mm pump is made from pure titanium, and weighs 370 g. The entire blood-contacting surface is covered with an anti-thrombogenic coating of diamond like carbon (DLC) or 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve blood compatibility. Flows exceeding 12 L/min against 100 mmHg pressure at 2600 rpm was measured. A low-temperature mechanical seal with recirculating cooling system is used to seal the shaft. EVAHEART demonstrated an acceptably low hemolysis rate with normalized index of hemolysis of 0.005 +/- 0.002 g/100L. METHODS: We evaluated the pump in long-term in-vivo experiments with seven calves. Via left thoracotomy, we conducted left ventricular apex-descending aorta bypass, placing the pump in the left thoracic cavity. RESULTS: Pump flow rates was maintained at 5-9 L/min, pump power consumption remained stable at 9-10 W in all cases, plasma free Hb levels were less than 15 mg/dl, and the seal system showed good seal capability throughout the experiments. The calves were sacrificed on schedule on postoperative day 200, 222, 142, 90, 151, 155, and 133. No thrombi formed on the blood contacting surface with either the DLC or MPC coating, and no major organ thromboembolisms occurred except for a few small renal infarcts. CONCLUSION: EVAHEART centrifugal blood pump demonstrated excellent performance in long-term in-vivo experiments.

Animals↗

PubMed2002

Perioperative advantages of off-pump coronary artery bypass grafting.

For the first time in Japan, off-pump coronary artery bypass grafting (OPCAB) was compared with the conventional on-pump technique, retrospectively examining the morbidity associated with coronary artery bypass grafting (CABG) and assessing the efficacy of OPCAB. In 2000, 158 patients underwent CABG: 95 patients (60%) had OPCAB (Group I) and 63 patients (40%) had conventional CABG (Group II). The operating time, length of intensive care unit (ICU) stay, ventilation time, postoperative bleeding, transfusion, postoperative renal function, occurrence of stroke, and early graft patency were examined in both groups. There were no hospital deaths in either group. The operating time, ICU stay, and ventilation time were significantly (p < 0.0001, p = 0.013, and p < 0.0001, respectively) shorter in Group I (351 +/- 85 min, 3.0 +/- 1.4 days, and 5.1 +/- 2.8h) than in Group II (449 +/- 112 min, 3.6 +/- 1.8 days, and 13.7 +/- 18.0 h). The postoperative blood loss within 12h and the transfusion volume were significantly (p = 0.0004 and p < 0.0001, respectively) smaller in Group I (480 +/- 210 ml and 300 +/- 490ml) than in Group II (720 +/- 430ml and 1,230 +/- 1,180 ml). Peak serum blood urea nitrogen and creatinine concentrations (excluding patients with preoperative chronic renal failure, ie a preoperative serum creatinine > 1.5 mg/dl) were significantly (p < 0.0001 and p < 0.0001, respectively) lower in Group I (16.2 +/- 15.2mg/dl and 0.81 +/- 0.72 mg/dl) than in Group II (19.2 +/- 7.6 mg/dl and 0.92 +/- 0.28 mg/dl). There were no perioperative strokes in Group I, but 6.4% of Group II patients suffered a stroke. There was no significant difference in graft patency between the groups (95.6% vs 94.9%). OPCAB reduced the mortality and morbidity of coronary revascularization, with a shorter operating time and more rapid recovery from surgery.

Aged↗

PubMed2002

Total arterial off-pump coronary revascularization with only internal thoracic artery and composite radial artery grafts.

OBJECTIVE: Total arterial off-pump coronary artery bypass (OPCAB) grafting with only internal thoracic artery (ITA) and composite radial artery (RA) grafts has been applied extensively to avoid cerebral complications and late vein graft failure. We evaluated the initial experience with this method by clinical and angiographic study. METHODS: Between April 2000 and May 2002, 257 patients underwent OPCAB grafting with this technique. The range of ages at operation was 42 to 86 years (mean, 66.1 +/- 8.6 years). On average, 3.28 +/- 0.86 grafts per patient were completed. More than 4 distal anastomoses were performed in 88 patients (34%). For coronary revascularization, 289 ITA and 555 RA grafts were used. The RA was used as a Y graft in 211 patients, as an I graft (for ITA extension) in 52 patients, and as a K graft (the side of the RA attached to the side of the left ITA) in 28 patients. Sequential bypass grafting was performed with 190 RA and 7 ITA grafts. The sites of distal anastomoses were 256 left anterior descending arteries (30%), 236 posterolateral branches (28%), 144 posterior descending arteries (17%), 106 diagonal branches (13%), 82 obtuse marginal branches (10%), and 19 right coronary arteries (2%). RESULTS: There were 1 operative death (0.4%) due to cerebral hemorrhage and 2 episodes of stroke (0.8%) during postoperative angiography. There were no clinical underperfusion syndromes or new intra-aortic balloon pump insertions. Perioperative myocardial infarction occurred in 12 patients (4.7%), sternal dehiscence in 5 (1.9%), and early coronary intervention in 4 (1.6%). There was no deep wound infection, reexploration for bleeding, or hand ischemia. The actuarial survival rate and the cardiac event-free rate at 2 years were 98.6% +/- 2.4% and 94.2% +/- 0.8%, respectively. Early postoperative angiography revealed a 97.8% (264/270) graft patency of ITAs and 97.9% (512/523) graft patency of RAs in 238 patients. Flow competition of the RA graft was recognized in 22 patients and, as indicated by follow-up angiographic study, did not cause late graft occlusion. CONCLUSIONS: OPCAB grafting with ITAs and composite RAs provides excellent early and intermediate clinical results and graft patency.

Adult↗

PubMed2002

Eight-year experience of combined valve repair for mitral regurgitation and maze procedure.

BACKGROUND AND AIMS OF THE STUDY: Although atrial fibrillation (AF) is often associated with severe mitral regurgitation (MR), a simultaneous maze procedure for AF associated with repair of MR remains controversial. In this study, mid-term results of combined mitral valve repair and the maze procedure were examined. METHODS: Between May 1992 and April 2001, 85 patients (61 males, 24 females) underwent valve repair for MR and the maze procedure. Mean age at surgery was 61.8+/-9.1 years; mean follow up was 4.7+/-2.3 years. Valve lesions were anterior in 26 patients (31%), posterior in 31 (36%), anterior + posterior in 23 (27%), and simple dilated annulus in five (6%). Chordal replacement with expanded PTFE sutures was performed in 40 patients (47%), and leaflet resection in 41 (48%). Ring annuloplasty was also applied in 61 patients (72%). Associated procedures were tricuspid valve annuloplasty in 33 (36%), coronary artery bypass grafting in four, atrial septal defect closure in two, aortic valve repair in one, and resection of abnormal septum in the left atrium in one. RESULTS: There was one hospital death (1%), and one late death (1%). Reopening the chest for bleeding was necessary in six cases (7%). One thromboembolic episode was detected during follow up (0.25%/patient-year). Reoperation for MR was performed in three patients (4%). Actuarial event-free survival rate was 90.0+/-6.4% at eight years. Sinus rhythm was regained in 68 patients (81%), and atrial A-wave was detected in 57 (68%) by pulsed Doppler study. Postoperative left ventricular diastolic and systolic dimensions were significantly (p = 0.001 and p = 0.017) smaller in patients who restored sinus rhythm than in those who did not (48.6+/-4.6 versus 54.6+/-4.7 mm, and 33.0+/-6.0 versus 38.1+/-6.9 mm). CONCLUSION: Combined mitral valve repair for MR and the maze procedure showed satisfactory midterm results. Postoperative sinus rhythm conversion by the maze procedure may reduce left ventricular size, and the incidence of thromboembolic episodes in mitral valve repair.

Adult↗

PubMed2002

Multiple off-pump coronary revascularization with "aorta no-touch " technique using composite and sequential methods.

BACKGROUND: Although off-pump coronary artery bypass grafting (OPCAB) has been widely applied in patients who are considered high risk for cardiopulmonary bypass (CPB), there is still a risk of stroke during the operation because of the ascending aortic partial clamp for proximal anastomosis. In the present study, we report the initial results of an "aorta no-touch " technique using an in-situ graft and composite and sequential grafting methods. METHODS: Between March 2000 and April 2001, 120 patients underwent OPCAB with this technique. The age of patients ranged from 47 to 86 years, with a mean age of 65.7 +/- 8.7 years. On average, 3.12 +/- 0.77 grafts per patient were completed. More than 4 distal anastomoses were performed in 32 patients (27%). As in-situ grafts, 140 internal thoracic arteries (ITAs) and 9 gastroepiploic arteries were used. The radial artery (RA) was used as a Y composite graft in 91 patients, as an I composite graft in 25, and as a K composite graft in 2. Sequential bypass grafting was performed using the RA in 60 patients, the saphenous vein (SV) in 6, the ITA in 4, and the gastroepiploic artery (GEA) in 3. Arterial grafts were used in 92% (345/374) of total bypass grafts. Distal anastomosed sites were 119 left anterior descending arteries (LADs) (32%), 90 posterolateral branches (24%), 64 posterior descending arteries (17%), 49 diagonal branches (13%), 39 obtuse marginal branches (10%), and 13 right coronary arteries (3.5%). RESULTS: There was no operative death or stroke. Early postoperative angiography revealed 95.5% (321/336) graft patency with 100% patency (119/119) of ITA to LAD grafts. Graft patency of the ITAs and RAs (98.5% and 95.9%) were significantly better than that of the GEA (79.0%, p = 0.0064 and p = 0.030) and saphenous vein (82.3%, p = 0.011 and p = 0.048). CONCLUSION: OPCAB performed with the aorta no-touch technique using an in-situ graft and composite and sequential grafting methods provides excellent early clinical results and graft patency.

Aged↗

PubMed2002

Effect of maze procedure in patients with atrial fibrillation undergoing valve replacement.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to elucidate the impact of the maze procedure on late outcome after valve replacement. METHODS: Between 1992 and 2000, 241 patients underwent the maze procedure combined with valve replacement. Patients were allocated to three groups: aortic valve replacement (AVR/maze, n = 16); mitral valve replacement (MVR/maze, n = 148); and combined aortic and mitral valve replacement (DVR/maze, n = 77). RESULTS: Mean follow up was 3.9 +/- 2.3 years. Hospital mortality was 0% in the AVR/maze group, 2.0% (n = 3) in the MVR/maze group, and 3.9% (n = 3) in the DVR/maze group. Elimination of atrial fibrillation (AF) at discharge was achieved in 74.3-75.9% of cases. Freedom from recurrence of AF/atrial flutter was 71.2% in the AVR/maze group, 68.2% in the MVR/maze group, and 64.0% in the DVR/maze group at five-year follow up. By multivariate analysis, risk factors for recurrence of AF/atrial flutter included preoperative enlarged left atrial dimension >70 mm, decreased postoperative fractional shortening <30%, and absence of postoperative left atrial contraction. Freedom from stroke was 93.6% in patients who achieved regular rhythm (normal sinus rhythm or junctional rhythm), and 80.9% in those with recurrence of AF at five years after surgery (p = 0.03). CONCLUSION: The combined maze procedure and valve replacement is safe and effective in selected patients. Restoration of regular rhythm significantly reduced the incidence of late stroke.

Adult↗