Biomedical subjects

Katsuya Ueno

Publications and source records attributed to Katsuya Ueno.

2 recordsLinked to original sources

PubMed2006

Multislice computed tomography accurately quantifies left atrial size and function after the MAZE procedure.

BACKGROUND: Although the MAZE procedure allows for the recovery of sinus rhythm and left atrial (LA) mechanical function in the great majority of patients with chronic atrial fibrillation (AF), the effects of MAZE on the precise LA geometry and wall motion remain to be elucidated. We hypothesized that LA size and mechanical function in patients with chronic AF and mitral valvular disease are well restored after MAZE. METHODS AND RESULTS: We studied 14 patients (MAZE group: mean+/-SD age, 63.9+/-8.6 years; 8 men and 6 women) who underwent MAZE for chronic AF and mitral valve surgery and 10 patients with sinus rhythm (coronary artery bypass graft [CABG] group: age, 70.0+/-7.9 years; 5 men and 5 women) who underwent CABG at Takeda Hospital between February 2002 and September 2005. MAZE was conducted by the endocardial application of radiofrequency ablation with a temperature-controlled multipolar radiofrequency catheter. LA volume and booster function were quantitatively evaluated by multislice computed tomography at 17.9+/-10.0 months (MAZE group) and 15.3+/-13.6 months (CABG group) postoperatively. All patients with MAZE were free of AF and other atrial arrhythmias during the follow-up period. In the CABG group, LA maximal and minimal volumes and ejection fraction were 109+/-12 mL, 82+/-11 mL, and 26+/-10%, respectively. In the MAZE group, LA maximal volume was 139+/-17 mL (P=0.187 versus CABG), and LA minimal volume was 121+/-16 mL (P=0.082 versus CABG), with an ejection fraction of 15+/-7% (P=0.004 versus CABG). In both groups, all parts of the LA wall contracted toward the geometric center of the LA. The extent of wall motion was significantly worse in the MAZE group compared with the CABG group. In both groups, LA booster function was inversely correlated with LA maximal volume. CONCLUSIONS: MAZE with radiofrequency ablation is safe and effective for the restoration of sinus rhythm in patients with chronic AF and mitral valve disease. However, chronic AF associated with mitral valve disease deteriorates LA mechanical function diffusely throughout the LA wall. Further studies with the use of multislice computed tomography are needed to sequentially evaluate LA function after MAZE in patients with and without mitral valve surgery.

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PubMed2005

Feasibility of the Inoue single-branched stent-graft implantation for thoracic aortic aneurysm or dissection involving the left subclavian artery: short- to medium-term results in 17 patients.

OBJECTIVE: This study assessed the short- to medium-term clinical results of the Inoue single-branched stent graft for repair of thoracic aortic aneurysms or dissections involving the left subclavian artery. METHODS: A retrospective review of experiences at two institutions was performed. We analyzed the data of consecutive 17 patients with thoracic aortic aneurysms or dissections who underwent endovascular repairs with the Inoue single-branched stent graft between July 1999 and April 2004. Complete baseline and follow-up data were available on all patients. The mean age was 71 +/- 9 years, and 13 of the patients (76%) were men. Eight patients (47%) were considered unfit for open surgery because of advanced age or the presence of comorbid diseases. RESULTS: The stent grafts were successfully delivered and deployed in all 17 patients. Periprocedural major complications, defined as those that caused any persistent disorder, occurred in one patient who developed spinal ischemia. A postoperative computed tomographic scan revealed three attachment site endoleaks; two endoleaks were from the proximal attachment sites and one endoleak was from the distal attachment site. The mean follow-up period was 26 months (range, 7 to 65 months). Two deaths occurred in the follow-up period from cerebral bleeding and pneumonia, both considered unrelated to the stent grafting. Two patients with attachment site endoleaks needed secondary stent-grafting; one patient required the implantation of a straight stent-graft in the distal attachment site and the other, the implantation of a double-branched stent-graft. Another patient with attachment site endoleak was considered very high-risk for open surgery or secondary stent grafting and did not undergo secondary intervention. The aneurysmal sac size of the patient has been stable for 28 months. The branched section of the stent graft was patent in all patients in the follow-up period. CONCLUSION: The results demonstrate the feasibility of the Inoue single-branched stent graft for thoracic aortic aneurysms or dissections involving the left subclavian artery.

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