Hirokuni Naganuma

Reconsideration of Patient-Prosthesis Mismatch Definition From the Valve Indexed Effective Orifice Area

BACKGROUND The objective of this study was to reassess the validity of defining patient-prosthesis mismatch (PPM) in the aortic position on the basis of an indexed effective orifice area (iEOA) less than 0.85 cm(2)/m(2). METHODS From June 1996 to March 2008, 342 patients underwent aortic valve replacement with a Carpentier-Edwards Perimount valve. From the data collected, the transvalvular pressure gradient was determined by the modified Bernoulli equation, and EOA was calculated from the standard continuity equation. RESULTS The actuarial survival rate at 10 years after surgery was 84.0% +/- 8.2%. The prevalence of PPM was 6.1% when a projected iEOA less than 0.85 cm(2)/m(2) was defined as indicating significant PPM. There was no difference between patients with moderate PPM (85.2% +/- 9.8%) and patients without PPM (81.0% +/- 8.7%; p = 0.44). The relation between mean transvalvular pressure gradient and iEOA demonstrated a gentler slope than that reported previously. Postoperative mean transvalvular pressure gradient was 17.4 +/- 5.6 mm Hg and 14.5 +/- 5.6 mm Hg in patients with an iEOA less than 0.85 and 0.85 or greater, respectively. Most patients had a postoperative mean transvalvular pressure gradient more than 10 mm Hg regardless of PPM. CONCLUSIONS Our analysis suggested that an iEOA less than 2.0 cm(2)/m(2) might be the threshold for PPM, which should not be passed to achieve a low mean transvalvular pressure gradient (less than 10 mm Hg) with the Carpentier-Edwards Perimount valve. The implications of these findings include the necessity for reassessing the hemodynamic performance of each type of prosthesis when attempting to define PPM, to avoid residual significant transvalvular pressure gradient.

Redefinition of tricuspid valve structures for successful ring annuloplasty

Background: Although numerous reports have described suturing techniques for tricuspid annuloplasty, most studies were not based on a detailed anatomy of the tricuspid annulus. Thus, the definition of the tricuspid commissures remains unclear. This study aimed to clearly define the commissures and leaflets of the tricuspid valve and subvalvular structures, and to define a standard method for tricuspid annuloplasty. Methods: In 27 normal heart specimens without cardiac disease, the tricuspid commissure was defined using indentations of the leaflets as a point, not an area, and the length of each tricuspid annulus was measured. The relationships between the leaflets and the subvalvular structures were then examined. Results: In most specimens, the posterior leaflet had 2 (62.9%) or 3 (29.6%) scallops, providing further evidence of posterior leaflet diversity. In addition, the posterior leaflet had 1 or 2 indentations, which can be mistaken for true commissures. The annulus of the posterior leaflet was significantly longer than the annuli of the other 2 leaflets (P < .00428). The annuli of the septal and the anterior leaflets were supported by the interventricular septum and the supraventricular crest, respectively, whereas the posterior leaflet annulus was distributed largely along the right ventricular free wall. Conclusions: There was a structural gap between the tricuspid leaflet indentations and the subvalvular structures. The relationships among the leaflets, commissures, and subvalvular structures differed in the septal, anterior, and posterior leaflets. This new definition of the commissural point may aid the development of a clear‐cut methodology for prosthetic ring annuloplasty.

A 22-year course of the Kay-Shiley disc valve with muscle guard at the mitral position.

Almost 33 years have elapsed since the introduction of the Kay-Shiley disc valve in Japan. Following the development of pyrolite carbon, the Kay-Shiley valve is no longer in clinical use. We report the case of a female patient who had had an isolated mitral valve replacement with the Kay-Shiley disc valve with single muscle guard 22 years previously. After numerous thromboembolic episodes with the Kay-Shiley disc valve, a successful reoperation was done with the CarboMedics valve. The explanted valve revealed that the grooved occluder disc had a loosely adherent clot. The thromboembolism is a notorious complication associated with this valve. We recommend re-replacement of the Kay-Shiley valve whenever possible.

A case report of aortic valve replacement following ruptured aneurysm of the sinus of valsalva with bicuspid valve

Only three cases of the combination of bicuspid aortic valve and ruptured aneurysm of the sinus of Valsalva, associated with previously repaired coarctation of aorta, have been reported. A twenty-year-old man with a sudden onset of CHF due to ruptured aneurysm of the sinus of Valsalva underwent intracardiac repair by direct closure of the sinus Valsalva in combination with patch closure of a subarterial VSD. Although, no AR was detected preoperatively, massive regurgitation occurred after the repair due to subsequent failure of aortic valve coaptation in the present of the bicuspid aortic valve, which was not diagnosed preoperatively. Aortic valve replacement with SJM 25 mm was successfully performed.

Technique of managing periprosthetic leakage due to mitral prosthetic valve endocarditis: report of a case

A patient with multiple leaks caused by active mitral prosthetic valve endocarditis with an annular abscess underwent repeat mitral valve replacement. To secure the new mitral prosthesis, sutures were placed through the healthy interatrial septal wall from right to left at the posteromedial region and then to the new prosthetic valve sewing cuff. In the anterolateral region, sutures were placed through the reconstructed annulus after debridement of the abscess and then reinforced with a pericardial xenograft patch. Postoperatively, the perivalvular leakage stopped and the patient recovered uneventfully.

Mid-Term Pulmonary Homograft Function for Right Ventricular Outflow Tract Reconstruction in the Ross Procedure.

海外では1980年代からhomograftが臨床応用されているが本邦での使用経験は希少である.今回Ross手術右室流出路再建にpulmonary homograftを用いた14例について検討した.Graft機能を心エコーによるpeak flow(PK),圧較差(PG),弁逆流について調べ,PGと患者の年齢,donor年齢,graft保存期間との相関関係も検討した.年齢は平均17.2歳,手術内訳はRoss手術10例,Ross-Konno手術4例,観察期間は23.1ヵ月であった.PK,PGはそれぞれ1.6±0.4m/s,11.9±5.2mmHgであった.弁逆流は1例にごくわずかに認めるのみであった.またPG-年齢,PG-donor年齢,PG-graft保存期間との間にはいずれも相関関係を認めなかった.23ヵ月の期間では,QOLに影響するような狭窄や弁逆流を認めず,右室流出路再建に用いる材質として優れていると考えられた.

Emergency Double Valve Replacement for Acute Mitral Regurgitation due to Ruptured Chordae Tendineae Associated with Congenital Bicuspid Aortic Valve Insufficiency.

僧帽弁逸脱症は腱索断裂を比較的高頻度に合併するが,感染性心内膜炎やMarfan症候群の合併なく急激に僧帽弁閉鎖不全を発症し,急性左心不全さらに,心停止にいたることは希である.今回,突然の急性左心不全にて発症し,救急外来受診直後心停止をきたした僧帽弁腱索断裂を伴う急性僧帽弁閉鎖不全症の43歳男性に対し,緊急手術を施行し良好な結果を得た.本症例では術中に先天性大動脈二尖弁による高度の閉鎖不全症の合併が判明し,これによる慢性左室容量負荷増大に加え,急性の腱索断裂が心停止をきたすほどの急性左心不全を招来した一因と考えられた.