Shinichi Ishii

Prevalence of pannus formation after aortic valve replacement: clinical aspects and surgical management

Pannus formation after aortic valve replacement is not common, but obstruction due to chronic pannus is one of the most serious complications of valve replacement. The causes of pannus formation are still unknown and effective preventive methods have not been fully elucidated. We reviewed our clinical experience of all patients who underwent reoperation for prosthetic aortic valve obstruction due to pannus formation between 1973 and 2004. We compared the initial 18-year period of surgery, when the Björk–Shiley tilting-disk valve was used, and the subsequent 13-year period of surgery, when the St. Jude Medical valve was used. Seven of a total of 390 patients (1.8%) required reoperation for prosthetic aortic valve obstruction due to pannus formation. All seven patients were women; four patients underwent resection of the pannus and three patients needed replacement of the valve. The frequency of pannus formation in the early group was 2.4% (6/253), whereas it was 0.73% (1/137) in the late group (P < 0.05). Pannus was localized at the minor orifice of the Björk–Shiley valve in the early group and turbulent transvalvular blood flow was considered to be one of the important factors triggering its growth. We also consider that small bileaflet valves have the possibility of promoting pannus formation and that the implantation of a larger prosthesis can contribute to reducing the occurrence of pannus.

Total cavopulmonary connection without the use of prosthetic material: Technical considerations and hemodynamic consequences

Total cavopulmonary connection with use of an autogenous intraatrial tunnel to create a straight tube between the inferior vena cava and the pulmonary artery was attempted in several types of cardiac anomaly in eight consecutive candidates for the Fontan operation. A small right atrium with an extraordinary location of the inferior vena cava and a short superior vena cava prevented the use of this procedure in two cases. By preserving the crista terminalis and the sinus node and its arteries we prevented the development of postoperative atrial arrhythmias in the short follow-up period, and the P trigger-signal averaged P waves were not different from those of other cardiac anomalies. The proximal stump of the superior vena cava was not incised in any case to enlarge the anastomosis, even when size mismatch between the superior and inferior venae cavae existed, as in a case of bilateral superior venae cavae. Stretching the vessels by approximately 150% was possible and permitted an adequate anastomosis. Cavopulmonary connections via the intraatrial tunnel ensured smooth, nonturbulent, somewhat pulsatile flow without a pressure gradient. We concluded that the creation of an autogenous intraatrial tunnel was possible in many cases without serious complications and that this procedure has potential benefit for the pulmonary circulation in the aspect of pulsatility.

Long-Term Results of Triple-Valve Procedure

Triple-valve procedures are associated with high early and late mortality. We reviewed our experience in 25 patients who underwent combined mitral and aortic valve replacement with tricuspid valve repair or replacement between 1979 and 2004. The mean follow-up was 7.8 years (range, 10 days to 24.5 years). The mean age at operation was 52 years (range, 31 to 72 years). Four patients underwent triple-valve replacement and 21 had double-valve replacement and tricuspid annuloplasty. Perioperative mortality was 20% and late mortality was 24%. Cumulative survival, calculated taking perioperative mortality into account, was 71% ± 10% at 10 years and 36% ± 15% at 15 years after surgery. Only 1 of 20 perioperative survivors required re-operation for prosthetic valve dysfunction. Double-valve replacement with tricuspid annuloplasty offers satisfactory long-term survival with freedom from thromboembolism and re-operation.

Mitral valve reconstruction: long-term results of triangular resection for degenerative prolapse

AbstractObjectives. Surgical treatment of a prolapsed anterior leaflet of the mitral valve is relatively difficult and controversial compared with management of a prolapsed posterior leaflet. The aim of this study was to assess the long-term results of mitral valve repair, focusing on triangular resection of the anterior leaflet. Methods. Between October 1991 and December 2006, surgical treatment for a prolapsed anterior leaflet was performed in 57 patients with degenerative mitral valve disease, including 49 patients who had anterior leaflet resection. Patients with mitral stenosis, ischemic mitral regurgitation, and congenital valvular disease were excluded. The mean age of the patients was 51.7 ± 15.9 years, and the mean follow-up period was 6.2 ± 3.8 years. Results. The overall actuarial survival rate and noreoperation rate at 10 years were 91.7% ± 4.1% and 92.3% ± 3.7%, respectively. Reoperation was performed in 2 (4%) of 49 patients who had anterior leaflet resection. All patients survived after reoperation, which involved mitral valve replacement. Postoperative echocardiographic studies showed that the mitral valve area was significantly smaller after repair in patients with anterior leaflet resection, but the area was still large enough for a functional valve. Among the 57 patients, 42 had no mitral regurgitation, whereas it was mild in 7 patients and moderate in 3 patients. Conclusion. Triangular resection of a prolapsed anterior leaflet of the mitral valve provides durable and reliable long-term results.

Validity of identifying patient-prosthesis mismatch from the indexed effective orifice area.

The main problem that arises from patient-prosthesis mismatch after aortic valve replacement is a residual high transvalvular pressure gradient, resulting in left ventricular overload. It was demonstrated by Pibarot and Dumesnil that the indexed effective orifice area should be larger than 0.85–0.90 cm2/m2 to prevent any significant transvalvular pressure gradient after operation. However, we have encountered a higher residual transvalvular pressure gradient than expected in some patients with an aortic stented bioprosthesis with an indexed effective orifice area greater than 0.85 cm2/m2. Based on our data, an indexed effective orifice area of less than 1.25 cm2/m2 might be considered the threshold for patient-prosthesis mismatch in patients with a stented bioprosthesis because this indexed effective orifice area is associated with a low mean transvalvular pressure gradient (less than 10 mmHg). The practical implications include the necessity to consider the hemodynamic performance of each prosthesis type when seeking to define patient-prosthesis mismatch and abnormally or significant high postoperative gradients that lead to an increased left ventricular workload, so as to avoid residual significant transvalvular pressure gradients and higher rates of morbidity and mortality.

Mitral Valve Plasty in the Active Phase of Infective Endocarditis with Intracerebral Mycotic Aneurysms and Abscesses in the Brain and Lower Limb

症例は38歳,女性.脳膿瘍および下腿膿瘍を合併した感染性心内膜炎により当院へ入院した.入院後の頭部CT検査で脳膿瘍,感染性脳動脈瘤を認めたが,心エコー検査で僧帽弁に径8mmの可動性疣贅を認めたために,準緊急的に疣贅切除術と僧帽弁形成術を施行した.術前にみられた発熱と下腿痛(筋内膿瘍)はすみやかに消失し,脳動脈瘤,脳膿瘍も退縮した.感染活動期に積極的に僧帽弁形成術を行い,全身症状の著明な改善を認めた貴重な経験であり,若干の文献的考察を加えて報告する.

Midterm results of mitral valve repair with the Carpentier-Edwards rigid ring

OBJECTIVE Prosthetic annuloplasty rings play an important role in mitral valve repair. This clinical study was undertaken to evaluate the midterm results obtained with the Carpentier-Edwards rigid ring. METHODS Between October 1991 and March 2005, 112 patients (mean age 53.0 years) underwent mitral valve repair with a Carpentier-Edwards rigid ring at our institution. Degenerative disease was the most frequent cause and a small number had other conditions such as endocarditis and rheumatic disease. Ten patients were in Carpentiers functional class Type I, 101 patients in Type II and 1 patient in Type III, based on valve pathology. Ischemic mitral regurgitation was excluded. The mean follow-up time was 5.3+/-3.6 years (range: 8 days to 12.3 years). All patients were completely followed by echocardiography. RESULTS The rigid ring ranged from 26 to 36 mm in diameter and the most common size was 30 mm. Although the mitral orifice area was decreased after mitral valve repair in all patients, none of them required reoperation because of mitral stenosis or left ventricular outflow tract obstruction (systolic anterior motion). Reduction of both systolic and diastolic left ventricular volumes was observed postoperatively. Ejection fractions were preserved in all cases. The actuarial survival rate was 92.0+/-3.0% at 10 years and the reoperation-free rate at 10 years was 96.0+/-2.0%. CONCLUSION The rigid ring has produced promising midterm results in terms of reoperation-free and survival rates.

Some techniques for the correction of the congenital heart disease with autologous flap

14 living flaps in 8 children were used to repair for the congenital heart disease, because artificial material and xeno grafts were shrunk in growing children but living flaps were going to glow with children. It were possible to use the living flaps to reconstruct of pulmonary outflow in truncus arteriosus, for septoplasty in partial anomarous of pulmonary venous return and reconstruction of unloofed coronary sinus in endocardial defect with triatriatum and intraatrial tunnel in TCPC or Fontan type operation.