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Takaaki Suzuki

Publications and source records attributed to Takaaki Suzuki.

13 recordsLinked to original sources
PubMed2006

Selective management of the left ventricular outflow tract for repair of interrupted aortic arch with ventricular septal defect: management of left ventricular outflow tract obstruction.

OBJECTIVE: Left ventricular outflow tract obstruction remains an early and late complication after repair of interrupted aortic arch and ventricular septal defect. We reviewed our experience with the selective management of the infundibular septum during primary repair to address left ventricular outflow tract obstruction. METHODS: From 1991 through 2001, all 27 patients presenting with interrupted aortic arch/ventricular septal defect and posterior deviation of the infundibular septum were analyzed. Fifteen patients with the smallest subaortic areas underwent myectomy or myotomy of the infundibular septum concomitant with interrupted aortic arch/ventricular septal defect repair. RESULTS: Patients undergoing myectomy-myotomy (Group I) had significantly smaller subaortic diameter indexes (0.83 +/- 0.16 cm/m2) when compared with those who had only interrupted aortic arch/ventricular septal defect repair (group 2: 0.99 +/- 0.13 cm/m2, P = .012). Two hospital deaths occurred in group 1, and 1 occurred in group 2. No late deaths occurred. No patient in group 2 required reoperation. Six group 1 patients required 9 reoperations for left ventricular outflow tract obstruction. Five patients underwent resection of a new subaortic membrane. Only 1 patient had recurrent muscular left ventricular outflow tract obstruction. Three patients required a second reoperation, primarily related to aortic valve stenosis. CONCLUSIONS: Interrupted aortic arch/ventricular septal defect with posterior malalignment of the infundibular septum can be repaired with low mortality in the neonatal period. Tailored to the degree of subaortic narrowing, resection or incision of the infundibular septum at the time of primary repair was very effective in preventing or prolonging the interval to recurrent left ventricular outflow tract obstruction compared with the published data. However, reoperation for left ventricular outflow tract obstruction, often related to the development of a new and discrete subaortic membrane or valvar stenosis, is still required in a subset of patients.

Aorta↗
PubMed2004

Intraoperative trans-mitral endoscopic resection of left ventricular tumor.

A successful resection of left ventricular tumor in an 82-year-old woman who had undergone coronary artery bypass grafting ten years ago is presented. In an attempt to make a procedure less invasive, we chose a trans-mitral endoscopic resection with minimum dissection because of reoperation on patient of advanced age. With the use of cardiopulmonary bypass and cardioplegic protection, the right side of left atrium was incised longitudinally. The endoscope was inserted in the ventricle via the mitral valve. A stalk of the tumor was cut by snare strangulation and the whole tumor was extracted endoscopically. The postoperative course was uneventful. To our best knowledge, this is the first report on endoscopic resection of the left ventricular tumor via a mitral valve. This method appear to be the choice in resecting the left ventricular tumor.

Aged↗
PubMed2003

Valve sparing aortic root replacement for dilatation of the pulmonary autograft and aortic regurgitation after the Ross procedure.

BACKGROUND: Aortic insufficiency secondary to progressive dilatation of the pulmonary autograft is being recognized with increasing frequency after the Ross procedure. We reviewed our experience with valve-sparing aortic root replacement concomitant with aortic annuloplasty to assess the effectiveness of this approach. METHODS: Four patients, aged 8 to 27 years, presented with moderate to severe aortic insufficiency associated with progressive root dilatation from 1 to 8 years after a Ross procedure. All patients had 0 to 1+ aortic insufficiency early after the Ross procedure, with a mean maximal sinus diameter of 37 mm (range 30 to 45 mm). At reoperation the maximum diameter of the root ranged from 45 to 55 mm (mean 50 +/- 4 mm). A valve-sparing aortic root replacement with annular reduction was performed. The annulus was decreased from a mean of 27 mm to 23 mm. For the root replacement, 1 patient underwent a standard root remodeling procedure; in the others, a separate piece of scalloped Dacron (C.R. Bard, Haverhill, PA) graft material was used for each sinus to facilitate optimal exposure. RESULTS: All 4 patients are in New York Heart Association functional class I at a mean follow-up of 6 months. The most recent echocardiography demonstrated 0 to 1+ aortic insufficiency with good left ventricular function. Histology of the excised pulmonary autograft walls demonstrated severe elastin fragmentation. CONCLUSIONS: Aortic root remodeling with annular reduction is an effective treatment for aortic root dilatation and aortic insufficiency after the Ross operation. This procedure allows correction of aortic insufficiency and avoids the need for a prosthetic valve and anticoagulation.

Adolescent↗
PubMed2003

Premature failure of small-sized Shelhigh No-React porcine pulmonic valve conduit model NR-4000.

OBJECTIVE: Given the limited availability of small-sized cryopreserved pulmonary homografts, we implanted a series of Shelhigh No-React porcine pulmonic valve conduits (SPVC). The aim of this study was to evaluate the short-term performance following implantation. METHODS: From February 2000 to September 2000, the SPVC was implanted 25 times in 24 patients in the right ventricular outflow tract (RVOT) to correct congenital anomalies. The anatomical malformations were TOF/PA in eight patients, TGA/VSD/PS in four, truncus arteriosus in four, IAA/VSD/AS or AA in four, l-TGA/VSD in two and other in two. Age at operation was 2.8+/-3.9 years (mean+/-SD), including 12 patients under 1 year. The median conduit size was 14mm (range, 10-18). RESULTS: At a mean follow-up of 23+/-5 months, two late deaths (8%) have occurred. Although they were not primarily conduit related, both showed severe conduit stenosis. Twenty-one conduits (84%) showed mild to severe conduit stenosis, regurgitation or both. Two patients underwent balloon dilatation for distal conduit stenosis. Twelve conduits (48%) in 11 patients were removed at a median of 12 months (range, 2-18 months) due to RVOT obstruction in 11 and free conduit insufficiency with pseudoaneurysm in one. The typical findings of the explanted conduits were prominent intimal peel formation at the distal anastomosis without calcification. The actuarial freedom from reintervention at 18 months was 48+/-10%. CONCLUSIONS: Our experience of the SPVC with the diameter of 14mm or less has revealed a high incidence of distal conduit stenosis due to intimal peel formation resulting in early conduit failure. These findings have led us to abandon its use when other options are available.

Bioprosthesis↗
PubMed2002

Successful surgical repair of a ventricular septal defect and high take-off of the right coronary artery in an infant.

A 6-month-old boy was admitted in acute distress because of severe dyspnea and intractable congestive heart failure. With a diagnosis of the ventricular septal defect, pulmonary hypertension and deteriorated lung function due to the respiratory syncytial virus infection, he was taken to the operating room to undergo banding of the pulmonary artery. However, an intraoperative finding of the anomalous high take-off from the right coronary artery made us to discontinue the banding procedure. After intensive medical management, he underwent a successful surgical repair of the defect with no ischemic injury to the myocardium. Congenital cardiac defects having this particular subset of anomalies of the coronary artery need to be repaired primarily since the palliative procedure near the anomalous coronary artery has a potential hazard to compromise the flow of blood through this artery.

Coronary Vessel Anomalies↗
PubMed2002

Arrhythmia after modified total cavopulmonary connection without use of prosthetic material.

BACKGROUND: Although total cavopulmonary connection without use of prosthetic material appeared to be a promising surgical procedure that would retain potential growth of the intraatrial tunnel, midterm incidence of arrhythmia remains unknown. METHODS: Twelve patients underwent modified total cavopulmonary connection. A prosthetic material was not used in 5 patients (group F) and was used in 7 patients (group P). A retrospective review of the perioperative electrocardiogram and ambulatory monitoring were performed. RESULTS: All patients revealed regular sinus rhythm before the operation. In the early postoperative period, the incidence of sinus node dysfunction was higher in group F than in group P (80% versus 28.6%). This difference no longer existed by hospital discharge (group F, 20%; group P, 14.3%). In the midterm follow-up period, sinus node dysfunction was detected in 4 patients of group F (80%) and 1 patient of group P (14.3%). Transient tachyarrhythmia was detected in 1 patient of group F and 3 patients of group P. CONCLUSIONS: Modified total cavopulmonary connection without use of prosthetic material affected unfavorably the sinus node in the early and midterm postoperative period.

Arrhythmias, Cardiac↗
PubMed2002

Shallow stitching close to the rim of the ventricular septal defect eliminates injury to the right bundle branch.

BACKGROUND: Complete right bundle branch block carries a deleterious effect on the long-term outcome of patients who undergo surgical treatment of the perimembranous ventricular septal defect. We describe a novel suturing method to reduce the prevalence of complete right bundle branch block. METHODS: From March 1996 through December 2000, 48 consecutive patients with perimembranous ventricular septal defect underwent patch closure using shallow stitches placed close to the rim (group 1). The same number of patients was randomly selected from those who had previously undergone surgery using deep stitches placed distant from the rim (group 2). Postoperative electrocardiograms were reviewed to compare the prevalence of complete right bundle branch block between groups. A morphologic study of the conduction system was performed to identify the vulnerable segment of the right bundle branch where the surgical damage tended to occur. Additional analyses were made to determine whether younger age and right ventriculotomy increased the prevalence of complete right bundle branch block. RESULTS: The prevalence of complete right bundle branch block in group 1 (6.3%) was significantly (p < 0.0001) lower than in group 2 (43.8%). The result was consistent with the morphologic finding that stitches of group 2 tended to damage the right bundle branch and those of group 1 did not. The younger age and right ventriculotomy did not increase the prevalence of complete right bundle branch block. CONCLUSIONS: Shallow stitches placed close to the rim of the perimembranus ventricular septal defect eliminate injury to the right bundle branch.

Age Factors↗
PubMed2002

Two-patch repair of complete atrioventricular septal defect using a small ventricular patch.

Since 1992, 19 patients with an atrioventricular septal defect have undergone surgical treatment using a novel annuloplasty technique in which a small ventricular patch was used to reduce the anterior-posterior dimension of the atrioventricular orifice. All patients recovered uneventfully and needed no reoperation for the residual regurgitation or shunt. The results showed that the new annuloplasty technique was promising, although a long-term result is yet to be seen.

Blood Vessel Prosthesis Implantation↗
PubMed2002

Word order preferences for direct and indirect objects in children learning Korean.

Pre-school Korean children typically manifest higher comprehension rates on the 'unmarked' SOV sentences of their language than on the 'scrambled' OSV patterns. To date, however, scant attention has been paid to children's ordering preferences with respect to direct and indirect objects. The results of an act-out comprehension experiment involving 40 subjects (aged 4;0 to 7;0) show a strong, statistically significant preference for the accusative-dative order, despite evidence that the reverse order is more common in mother-to-child speech. Two hypotheses are considered, one involving the relationship between word order and grammatical relations and the other involving the relationship between word order and the types of situations denoted by the sentences in question. The results of a follow-up study involving transitive verbs with instrument arguments provide strong evidence in favour of the latter hypothesis.

Child↗
PubMed2002

Perspective-taking and comprehension of passive sentences by Japanese-speaking children.

This study demonstrates that children's difficulties in the interpretation of passives are attributed to their perspective-taking ability. Thirty-six Japanese preschool children participated in act-out sentence comprehension tasks. They were asked to manipulate two toy animals to demonstrate the meaning of two types of stimulus sentences: Type I had the child's toy, whose reference involved the child's actual name (e.g.. Jun-kun no neko "Jun's cat") encoded as grammatical subject, while Type II had the child's toy encoded as non-subject. Since passive structures take the perspective of the patient-denoting subject NP, it is assumed that only Type I passives have the perspective that matches that of the child. The results show that children's performance on passives was significantly better in Type I than in Type II sentences. But this difference was not observedfor active sentences. For those who showed (nearly) perfect performance on active sentences, only Type I passives were equally well understood. These results strongly suggest that perspective-taking difficulties mask children's true competence on passives and that even 6-year-olds may not yet have attained the fill perspective-taking ability required for comprehension of passive sentences.

Child↗