Jun Kawamoto

Early aortic bioprosthetic valve deterioration in an octogenarian.

We experienced extremely early aortic bioprosthetic valve deterioration with leaflet calcification and stiffening 2 1/2 years after aortic valve replacement in a female octogenarian. We could not identify the possible reason for this devastating complication; however, daily calcium supplement consumption may play a role of acceleration of calcium deposition in the leaflets of implanted bioprosthetic heart valves.

Aortic root replacements in reoperations

We evaluated 4 patients who had undergone previous cardiac surgery underwent reoperation involving aortic root replacement. Subjects were a 55-year-old man who had undergone separate valve graft replacement for a dissecting aneurysm (DeBakey type I) 3.25 years earlier; a 51-year-old woman who had undergone separate valve graft replacement for a dissecting aneurysm (DeBakey type I) 6 years earlier; a 66-year-old woman who had undergone aortic valve replacement and single coronary artery bypass grafting for severe aortic regurgitation, angina pectoris, and aortitis syndrome 11 years earlier; a 47-year-old man who had undergone mitral valve replacement and 3-coronary artery bypass grafting for severe mitral regurgitation and angina pectoris 4 years earlier. Development of a surgical technique, coupled with myocardial protection, and pharmacological treatment at reoperation yielded excellent early surgical results. To reduce the incidence of reoperation and ensure satisfactory long-term results, we recommend radical management for the individual case be selected at initial operation and entire resections be conducted for aneurysmal degeneration or dissected segments.

Transaortic Correction of Systolic Anterior Motion of the Mitral Leaflet After Aortic and Mitral Valve Replacement

Left ventricular outflow tract obstruction is a rare and critical complication after mitral valve replacement. We report a patient who presented with severe left ventricular outflow tract obstruction caused by systolic anterior motion of the native mitral leaflet after aortic and mitral valve replacement. The patient was successfully treated by resection of the anterior mitral leaflet through the 19-mm bioprosthetic valve in the aortic position. This approach is quite simple and effective, even through the small aortic bioprosthesis, and does not require a second mitral valve replacement.

Clinical evaluation of right gastroepiploic artery (rgea) graft —Comparison of RGEA with right internal thoracic artery (RITA) graft in the coronary bypass grafting (CABG) operation using only arterial grafts—

From January, 1990 through May, 1997, 100 CABG operations were conducted using only double arterial grafts. RITA/left internal thoracic artery (LITA) (n = 38) and RGEA/LITA (n = 62) groups were compared. The incidence of left main trunk lesion was higher in the RITA/LITA group (29%: 13%), and old myocardial infarction was greater in RGEA/LITA group (77%: 55%). Mean age in the RGEA/LITA group showed high tendency (66.8 +/- 8.5: 63.9 +/- 9.2). Both groups were essentially the same with respect to sex, poor left ventricular function, pre-operative aortic baloon pumping (IABP), diabetes mellitus, hypertension, cerevral vascular disease, hyperlipidemia, smoking, pre-operative ejection fraction (EF). Focal skin infection (32%: 6%) and total operative field infection (focal skin infection + mediastinitis) (39%: 8%) were higher in the RITA/LITA group. Operation time (443 +/- 81: 405 +/- 114) and pleural effusion (29%: 15%) showed high tendency in the RGEA/LITA group. Extracorporeal circulation time, aorta cross-clamping time, reoperation due to bleeding, reoperation due to mediastinitis, post-operative IABP, and post-operative EF were the same for the two groups. The difference of survival rate and cardiac event-free rate between two groups were not recognized. The RGEA/LITA group showed lower complication and similar survival rates than the RITA/LITA group. Based on the present results. RGEA may be considered more usefull than RITA.

Differences in Prosthetic Graft Images Obtained by Three-dimensional CT Angiography.

当施設で末梢動脈バイパス手術に用いたIMPRA™, Bionit™, GELSOFT™, 大伏在静脈の4種類のグラフト材料について, グラフト閉塞の場合とグラフト開存の場合に分けてその描出像を比較検討した. グラフト開存の場合は4種類のいずれも3D-CTAでグラフトが描出され, CT横断像でも内腔が高輝度に描出された. グラフト閉塞の場合, IMPRAと Bionit は3D-CTAでグラフトが描出されるもののCT横断像では内腔は低輝度であった. GELSOFTと大伏在静脈は3D-CTAでグラフトが描出されず, CT横断像でも内腔は低輝度であった. IMPRAと Bionit はグラフト閉塞の場合でも人工血管そのものが描出されるので注意を要することがわかった. グラフト開存の確実な診断のためには, バイパス末梢側の native 血管が造影されることと, 三次元画像構築前のCT横断像にてグラフト内腔が高輝度に描出されていることを確認する必要がある. またCTの閾値を変化させると閉塞血管が虫喰い状に描出されるので診断の参考となる.

Assessment of the Usefulness of Three-dimensional CT Angiography after Peripheral Arterial Bypass Surgery.

1994年10月から1996年4月までに末梢動脈バイパス術を施行した17症例26グラフトについて術後DSAと術後3D-CTAを施行し比較検討を行った. グラフト開存17例ではすべての症例で(1)3D-CTAにおける人工血管あるいは大伏在静脈の描出, (2)3D-CTAにおけるバイパス末梢側 native 血管の描出, (3)CT横断像にてグラフト内腔の造影剤充満の3条件が満たされていた. グラフト閉塞9例では, 閉塞にもかかわらずグラフトの描出されたものが5例にみられ, グラフトが描出されかつ末梢側血管も描出されたものが3例にみられた. ただしCT横断像にてグラフト内腔の造影剤充満を認めた症例はなかった. (1)(2)(3)の3条件はグラフト開存診断のための必要条件であると考えられた.