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Biomedical subjects

M R Chen

Publications and source records attributed to M R Chen.

At least 55 records · Page 3Linked to original sources
PubMed1989

Is the sinus node visible grossly? A histological study of normal hearts.

The sinus node is said to be occasionally visible in the human heart, while some have denied this visibility. This histological study of the normal sinus node was made on 11 adults and 10 infants. The node was always located subepicardially along the terminal groove at the junction of the superior caval vein and the right atrium. When no fatty infiltration (all infants and 2 adults) or minimal fatty tissue (2 adults) was found over the epicardial side of the node, it was not visible grossly. When fatty infiltration was obvious, then the node could be identified grossly as a yellowish spindle-shaped structure along the terminal groove. This arrangement was observed in 7 adults. The majority of nodes were in lateral position, but the so-called horseshoe arrangement was seen in 2 infants and 2 adults. The artery to the sinus artery was located centrally or eccentrically in the majority of cases, but the artery ramified through the nodal substance in 1 infant and 4 adults. We conclude that the node is not visible grossly in either the infant hearts or in those adult hearts without fatty infiltration. The whole cephalic part of the terminal groove should be carefully avoided to be sure of preventing the injury to the node during cardiac surgery.

Adult↗
PubMedDate not supplied

Clinical implications of short-axis aortopulmonary rotation on juxtacommissural origin of the coronary artery in transposition of the great arteries and surgical strategy.

BACKGROUND: The relationship of short-axis aortopulmonary rotation (APR) with juxtacommissural origin of the coronary arteries (JOCA) in transposition of the great arteries (TGA) has never been elucidated. The surgical outcome of arterial switch operation (ASO) is influenced by the presence of JOCA. METHODS: Fifteen patients with TGA who presented to our institution between 1988 and 1995, and 23 cases from the literature, all with documented JOCA and APR, were analyzed. Each coronary arterial type was assigned to one of five patterns, according to similarities of epicardial configuration. All our patients underwent an ASO with various techniques to deal with JOCA. RESULTS: JOCA near the facing commissure (FC, 35 cases), were more frequent with anterior TGA (29/31, 94%) except types 5cj and 9j that were seen with posterior and right lateral TGA (4/4, 100%); whereas JOCA near the right-hand nonfacing commissure (RNC, 3 cases) were related with posterior TGA. Eta-square analysis showed significant correlation between various JOCA and short axis APR. Thirteen of our cases had JOCA near FC, two near RNC. Five of the former in whom the coronary artery was excised as a single button had a superior trapdoor; using a two-button technique three of the former had a lateral funnel and one of the latter had a medial trapdoor for the JOCA; all survived although on late noncoronary death was noted. In the remaining six cases without augmentation, only one survived (8/1 vs 1/5, p < 0.02). CONCLUSION: JOCA in TGA was related to short axis APR, generally near FC in anterior TGA (except types 5cj and 9j), and near the RNC in posterior TGA. A superior (lateral) or medial flap, to augment the coronary button for JOCA near FC or RNC is helpful for a successful ASO.

Aorta↗
PubMedDate not supplied

Tuberous sclerosis with visceral organ involvement.

This study is to determine the incidence of visceral organ involvement in tuberous sclerosis (TS). We reviewed 30 cases of TS diagnosed between 1987 to 1997. There were 17 males and 13 females, ages ranged from one day old to 17 years old. Among the 30 cases, 25 patients had seizures and skin manifestations; 24 had cerebral tubercles; 10 had heart involvement (9 rhabdomyoma, 1 dilated cardiomyopathy); 4 had kidney involvement (3 polycystic kidney disease, 1 renal hamartoma); and 3 had retinal astrocytic hamartoma. Based on our study, the most common visceral organs involved were the heart and kidney. Among the ten patients with cardiac rhabdomyoma, six were less than 1 year old (mean age 1.6 +/- 2.2 years old). One newborn presented with a cardiac mass diagnosed by prenatal sonography and another newborn, noted to have tachycardia after birth, underwent surgical intervention due to impending heart failure. Four patients had kidney abnormalities; three were less than 5 years old (mean age 5.2 +/- 5.2 years). During this 10 year period, there was no mortality seen among patients with visceral organ involvement. We suggest that clinicians treating patients with TS should not overlook the visceral organs, especially heart and kidney, which, if involved can have significant morbidity.

Adolescent↗
PubMedDate not supplied

Midterm outcome of mitral valve regurgitation after repair of atrioventricular septal defect.

The purpose of this retrospective study was to evaluate the outcome of mitral regurgitation (MR) following repair of atrioventricular septal defects (AVSDs). Echocardiograms of all survivors after AVSD surgery between 1991 and 1996 were reviewed. This study enrolled 16 patients who had had more than two postoperative color Doppler studies. On each echocardiogram, MR severity was graded on a 1+ to 4+ scale, based on the size of the MR jet. Mean age at surgery was 31.1 months (range 2.5 to 83) and mean postoperative follow-up duration was 23.6 months (range 1 to 59). Mild deterioration of mitral valve function was common. MR severity increased by one or more grades in 5 patients (31%) between the initial and final examinations. However, the deterioration in mitral valve function occurred primarily on the immediate postoperative stage. On mid-term follow-up, the MR improved, or at least became stationary, in all patients. Mitral valvuloplasty was not necessary in surviving patients. We conclude that postoperative MR remains fairly stable following AVSD repair. Serious deterioration is rare.

Child↗
PubMedDate not supplied

Cardiovascular function in young patients with type 1 diabetes mellitus.

Echocardiographic assessment of cardiovascular function was performed in 47 type 1 diabetic patients and 30 healthy control subjects of comparable age, height, weight, and heart rate. Indexed left ventricular mass, stroke volume, cardiac output, cardiac index, shortening fraction, indexed diastolic dimension, and indexed diastolic volume were calculated and compared between patient and control groups. Left ventricular mass and performance were slightly elevated in type 1 diabetic patients compared with 30 healthy control individuals. However, only cardiac output had borderline statistical significance (p = 0.06). The reason might be short duration (mean, 4.02 +/- 4.07 years) of diabetes in our patients group. In 18 of 47 patients the duration of type 1 diabetes was even less than two years. Relation of left ventricular mass to independent variables showed that, left ventricular mass was significantly correlated with stroke volume (p = 0.008), cardiac index (p = 0.0005), indexed systolic blood pressure (p = 0.0000199), indexed diastolic blood pressure (p = 0.0000172) and left ventricular contractility (p = 0.000273) in diabetic patients. Left ventricular contractility was also independently associated in diabetic patients with the indexed systolic and diastolic blood pressure (p = 0.0000755 and 0.000678 respectively). Albumin excretion, duration of diabetes, glycosylated hemoglobin (HbAlc), serum creatinine, and left ventricular preload did not have significant univariate correlation with left ventricular contractility.

Child↗
PubMedDate not supplied

Midterm results of aortic valve reconstruction for congenital aortic stenosis with or without regurgitation.

Aortic valve is often replaced if valvular stenosis fails to be balloon dilated. Aortic valve reconstruction was performed on 4 patients from August 1993 to 1999. Their ages ranged from 1 month to 15 years (mean 8.3 years). Unicuspid aortic valve was present in three of them and bicuspid in the other one. Two patients were associated with a patent arterial duct, one aortic regurgitation, and one pulmonary stenosis. Commissurotomy was done in three of them to transform the aortic valve into tricuspid except one, in whom bicuspid valve was preserved. In one case with unicuspid aortic valve, a piece of tanned autologous pericardium was used to augment one myxomatous and retracted leaflet. The sinus of Valsalva was molded together with a bulging shape of its aortic leaflet. All four were weaned from cardiopulmonary bypass smoothly. Transesophageal echocardiography in one case prompted rebypass to decrease the degree of regurgitation from moderate to mild by further shaping of the leaflet and sinus of Valsalva. In one patient chylopericardium was complicated and subsided in 5 days after conservative treatment. All patients were doing well on follow up at 56.8 +/- 34.4 months after surgery, with trivial to mild systolic pressure gradient (20 +/- 26 mmHg; preoperatively: 88 +/- 36 mmHg) and mild regurgitation. Aortic valve reconstruction is feasible in the setting of congenital aortic stenosis in our limited experience; repair instead of replacement is recommended even when regurgitation is present.

Adolescent↗
PubMedDate not supplied

Intestinal pseudo-obstruction followed by major clinical features of Kawasaki disease: report of one case.

Kawasaki Disease (KD) or atypical KD (AKD) rarely presents with intestinal obstruction or pseudo-obstruction. Others have reported gastrointestinal symptoms appearing with and up to 4 weeks after the occurrence of major clinical symptoms of KD. However, we presented a 1-year-old boy with prolonged fever who was found to have pyuria and liver dysfunction on the fourth day of fever. He developed a picture of intestinal pseudo-obstruction including bilious vomiting and abdominal distention on his fifth day of fever, four days before he developed the fissured lips. Because of the emergence of four major clinical criteria of KD, coronary artery dilatation, and aseptic meningitis, AKD was initially diagnosed and prompted the use of intravenous immunoglobulin on the tenth day of fever. Hydrops of the gallbladder, leukocytosis, increased ESR, and thrombocytosis were noted during hospitalization. These atypical features rarely develop all together in one patient with KD or AKD. Nevertheless, our patient had early intestinal pseudo-obstruction with almost all of the above unusual systemic manifestations and the late occurrence of clinical features of KD. We demonstrate that intestinal pseudo-obstruction in KD may develop earlier than other major clinical features and may improve under the conservative treatment. Surgery should be reserved for those who have complete intestinal obstruction presenting with significant peritoneal signs.

Humans↗
PubMedDate not supplied

Metabolic disturbance in obese children: glucose, insulin levels and lipid profile.

Obesity is a common nutritional disorder among children and adolescents. The purpose of this study was to investigate the biochemical changes in obese children in Taiwan, in comparison with those observed by other authors. Children with weights above 120 percent of ideal body weight were considered obese. Serum glucose, insulin, uric acid, and creatinine levels and lipid profiles of 298 obese children (mean age 11.3 +/- 2.4 years, 158 boys) and 60 controls (mean age 11.6 +/- 2.2 years, 38 boys) were determined using accepted procedures. Demographic and serum biochemical characteristics were compared between obese and control groups overall and by gender. Serum glucose, insulin, cholesterol, and triglyceride levels, known risk factors for coronary heart disease, were higher in the obese patients than in the control group. Early treatment and prevention of childhood obesity may keep the metabolic disturbance from deteriorating and becoming risk factors for coronary heart disease.

Adolescent↗
PubMedDate not supplied

Clinical observation of meconium peritonitis.

Twenty cases of meconium peritonitis were found between September 1980 and March 1988 at Mackay Memorial Hospital. The male to female ratio was 1.5 to 1. Six of the 20 cases involved premature babies. The great majority presented symptoms and signs before 5 days old, but one case was not diagnosed until 13 months of age. Polyhydramnios of the mother was found in six cases (30%). Abdominal distension was the universal symptom in all 20 cases. Hydrocele was noticed in 8 of the 12 male babies. In seven cases (35%) radiological examination showed abdominal calcifications. All patients underwent surgical intervention. Peritonitis was of cystic type in seven cases (35%); fibroadhesive in nine cases (45%); generalized in four cases (20%). Evident intestinal perforation was noted in 13 patients, and a mechanical obstructive lesion was found in 9 cases (45%) including intestinal diaphragm, atresia, volvulus, and Hirschsprung's disease. In only two patients (10%) was neither evident perforation nor obstructive lesion. The overall mortality rate was 30% (6/20), with no mortality after 1986 (0/6). The mortality seemed increased in those associated with perforation (4/13) and midgut volvulus (2/2) in particular, compared with non-perforation cases (1/7). It appears that early aggressive operation, and meticulous postoperative care, have contributed to the higher survival rate in recent years.

Cysts↗
PubMedDate not supplied

The VATER association: analysis of forty six cases without karyotyping.

Forty-six patients with two or more features of the VATER association admitted to the Mackay Memorial Hospital from May, 1983 to Mar, 1992 were retrospectively enrolled in this study. We compared the incidence of major features with that reported in the literature. Imperforate anus, congenital heart disease, and renal anomalies were the three most common major features in our study. Thirteen patients died. Heart failure was the major cause of mortality. We noted many patients associated minor features, and among them there was a relatively high ratio of cleft lip, cleft palate, and hypospadius. The overall outcome and development were good among the survivals. We suggest that children who have any congenital anomaly included in the VATER association should get a careful examination and evaluation of their heart, genitourinary tract, limbs and vertebrae. Early correction if possible is indicated in such patients.

Abnormalities, Multiple↗
PubMedDate not supplied

Embolization of the major aorto--pulmonary collateral artery in tetralogy of Fallot: report of one case.

A boy with tetralogy of Fallot diagnosed in infancy, presented for definitive correction at the age of 5 years and 3 months. He had undergone bilateral Blalock-Taussig shunts twice at 1 and 2 years of age, respectively. Cardiac catheterization and angiography prior to total correction revealed a major aorto-pulmonary collateral artery arising from the thoracic aorta and supplying the right upper lung. Embolization of the collateral artery with two platinum coils (via catheterization) was performed. The successful embolization exempted the patient from the risky ligation of the deeply located collateral artery.

Aorta↗