Biomedical subjects

Koichi Toda

Publications and source records attributed to Koichi Toda.

6 recordsLinked to original sources

PubMed2005

Recovery from hemorrhagic pulmonary damage by combined use of a left ventricular assist system and right ventricular assist system and extracorporeal membrane oxygenation.

A 13-year-old boy developed cardiogenic shock secondary to end-stage dilated cardiomyopathy and extracorporeal life support (ECLS) was initiated. However, pulmonary hemorrhage occurred due to severe pulmonary hypertension. He underwent implantation of a left ventricular assist system (LVAS) and right ventricular assist system (RVAS) plus extracorporeal membrane oxygenation (ECMO) shunting between the right and left atrium. Pulmonary damage was resolved and RVAS-ECMO was terminated after 8 days of support.

Adolescent↗

PubMed2005

The "eaves" technique for distal anastomosis in aortic arch replacement.

We describe the "eaves" technique, a new method for distal anastomosis in aortic arch replacement. The 1-cm wide eaves were created at the site 3 to 4 cm distal to the graft end. The graft was bound with vessel tape from the eaves to the site proximal to the origin of the first branch to make a working space above the eaves and to facilitate graft handling. Then the native descending aorta was sutured to the eaves easily. The eaves enabled a greater surface contact area between the graft and the inner wall of the aorta and reduced bleeding at the anastomosis.

Anastomosis, Surgical↗

PubMed2005

Impact of ostial stenosis on the Doppler flow profiles in internal thoracic artery graft.

As ostial stenoses of internal thoracic artery (ITA) grafts rarely occur after coronary artery bypass grafting, little is known about their Doppler flow profile. This report describes changes in the Doppler flow of ITA grafts with ostial stenosis after surgical repair of the stenosis. A 54-year-old male underwent coronary artery bypass grafting (CABG) in which the left ITA was anastomosed to the left anterior descending coronary artery. The follow-up coronary angiography revealed an ostial 90% stenosis of the ITA. The patient underwent elective surgery during which the radial artery was interposed between the left subclavian artery and the ITA. Intraoperative ultrasonography was performed immediately before cut down of the ITA graft and again immediately after completion of all anastomoses. Both diastolic and systolic velocities and the velocity time integral increased more than 2-fold after the repair. Neither the diastolic-to-systolic peak velocity ratio nor the diastolic velocity time integral fraction showed remarkable change. These profiles were different from those reported previously for distal stenosis.

Constriction, Pathologic↗

PubMed2003

Changes in left anterior descending coronary artery flow profiles after coronary artery bypass grafting examined by means of transthoracic Doppler echocardiography.

OBJECTIVE: We sought to investigate the changes of velocity profiles in the left anterior descending coronary artery after coronary artery bypass grafting using transthoracic Doppler echocardiography. METHODS: Forty-five patients who received a bypass graft to the left anterior descending coronary artery were studied. Before coronary artery bypass grafting, Doppler velocity profiles of the distal left anterior descending coronary artery were recorded with transthoracic Doppler echocardiography. Peak systolic velocity, mean systolic velocity, peak diastolic velocity, mean diastolic velocity, total velocity time integral, systolic velocity time integral, and diastolic velocity time integral were measured. Three weeks after coronary artery bypass grafting, left anterior descending coronary artery antegrade flow in the distal portion of the anastomosis was obtained by using the same method. Coronary angiography was performed before and 3 weeks after coronary artery bypass grafting. RESULTS: The overall success rate of measuring the left anterior descending coronary artery flow was 60.0% preoperatively and 80.0% postoperatively. In 25 patients, in whom all parameters were obtained both before and after coronary artery bypass grafting, the following increased significantly after coronary artery bypass grafting: peak systolic velocity (14.86 +/- 7.50 vs 25.07 +/- 17.02 cm/s, P =.0045), mean systolic velocity (9.86 +/- 5.42 vs 18.03 +/- 12.94 cm/s, P =.0026), peak diastolic velocity (24.26 +/- 12.54 vs 48.28 +/- 31.66 cm/s, P =.0021), mean diastolic velocity (14.94 +/- 6.65 vs 30.36 +/- 20.71 cm/s, P =.0022), diastolic velocity time integral (7.22 +/- 2.88 vs 15.55 +/- 10.39 cm, P =.0009), total velocity time integral (10.50 +/- 4.48 vs 19.27 +/- 12.63 cm, P =.0034), and diastolic-to-systolic velocity time integral ratio (3.09 +/- 1.53 vs 4.97 +/- 2.75, P =.0044). Angiography showed graft patency and no significant change in left anterior descending coronary artery stenosis in all patients. CONCLUSIONS: Transthoracic Doppler echocardiography showed a significant increase in some parameters in left anterior descending coronary artery flow after coronary artery bypass grafting. Measurement of left anterior descending coronary artery flow by means of transthoracic Doppler echocardiography might be a noninvasive method to evaluate the effect of bypass grafting on the left anterior descending coronary artery.

Aged↗

PubMed2003

Aortic arch replacement with proximal first technique.

BACKGROUND: Deep hypothermic circulatory arrest (DHCA) without retrograde cerebral perfusion (RCP) has a strict time limit. We modified a surgical technique for anastomosis to shorten the period of DHCA and unilateral cerebral perfusion (UCP). METHODS: Between March 1993 and August 2001, retrospective analysis was done on 23 consecutive patients, who underwent aortic arch replacement with branches. The patients were divided into two groups: DHCA group and UCP group. The DHCA group, in which DHCA alone and without additional cerebral perfusion was performed, comprised of nine patients. Proximal aortic anastomosis was performed first during systemic cooling; then both the brachiocephalic artery and left carotid artery were reconstructed with the branches of the artificial graft during circulatory arrest; thereafter, cerebral and coronary perfusions were resumed. The UCP group, in which DHCA was not used but right hemisphere perfusion during deep hypothermia was performed when the origin of brachiocephalic artery was safely clamped, consisted of 14 patients. RESULTS: Mean time of DHCA was 18.8+/-4.2 minutes and that of right hemisphere perfusion time was 11.0+/-3.8 minutes, respectively. Twenty-one patients survived the surgery (91.3%), and two (8.7%) died during hospitalization. Transient cerebral complication occurred in four patients in the DHCA group and all recovered. Logistic regression analysis revealed that DHCA was the only parameter to significantly influence temporary neurological dysfunction. There was no other significant difference between the two groups. CONCLUSION: With our modified and simple surgical technique for aortic arch repair, we were able to successfully shorten the DHCA time and right hemisphere perfusion time. However, because DHCA was the only parameter to significantly influence temporary neurological dysfunction, some form of continuous cerebral perfusion at deep hypothermia may be a safer method to preserve cerebral function.

Adult↗

PubMed2002

Revascularization in severe ventricular dysfunction (15% < OR = LVEF < OR = 30%): a comparison of bypass grafting and percutaneous intervention.

BACKGROUND: We sought to determine the optimal approach to revascularization of patients with severe left ventricular (LV) dysfunction. METHODS: We conducted a single-center observational study of 117 consecutive patients who had severe LV dysfunction (15% < OR = LV ejection fraction < OR = 30%) and underwent either coronary artery bypass grafting (CABG, n = 69) or percutaneous revascularization (n = 48) between 1992 and 1997. RESULTS: The CABG group was younger (62 versus 67 years, p = 0.026), and fewer previous bypasses (7% versus 40%, p < 0.0001) and fewer prior percutaneous revascularizations (16% versus 42%, p = 0.0019) were noted. More vessels were revascularized (3 +/- 0.8 versus 1.5 +/- 0.7, p < 0.0001), and revascularization was more complete by CABG (84% versus 48%, p < 0.0001). Morbidity and mortality at 30 days were similar, and there was no significant difference in 3-year survival (73% versus 67%), although 3-year cardiac event-free survival (52% versus 25%, p = 0.0011) and 3-year target vessel revascularization-free survival (71% versus 41%, p < 0.0001) were significantly better in the CABG group, and LV ejection fraction was significantly improved after CABG. In the subgroup of patients 65 years of age or older and those without proximal left anterior descending coronary artery lesions, significant benefit of CABG in cardiac event-free and target vessel revascularization-free survival disappeared. CONCLUSIONS: We found that in clinically selected patients with severe ventricular dysfunction, CABG compared with percutaneous revascularization achieves more complete revascularization, improved LV function, fewer cardiac events, and fewer target vessel revascularizations, but does not affect mid-term survival. A prospective controlled trial with defined criteria for treatment assignment is warranted to confirm our results regarding the two revascularization strategies in patients with severe LV dysfunction.

Age Factors↗