Biomedical subjects

I S Chiu

Publications and source records attributed to I S Chiu.

At least 37 records · Page 2Linked to original sources

PubMed1999

Airway management and transesophageal echocardiographic monitoring for pulmonary artery sling.

Pulmonary artery sling is an uncommon vascular anomaly and can be life threatening when it causes tracheal compression. We report on a 14-day-old boy who presented with respiratory distress soon after birth. A series of examinations showed tracheal stenosis due to a pulmonary artery sling. Surgery was performed with the aid of cardiopulmonary bypass. The external compression and intrisic stenosis could not be resolved by vascular surgery because of tracheal malacia and a complete tracheal ring. We recommend cutting extra holes 1 to 2 cm from the distal end of the endotracheal tube for endobronchial intubation. The airway obstruction was resolved successfully with a custom-made endobronchial tube. However, the patient died of pneumomediastinum and pneumothorax induced by barotrauma, on the fourth postoperative day.

Bronchi↗

PubMed1998

Transarterial approach of the pulmonary artery in anatomically corrected malposition of the great arteries by manipulating a catheter inverted with balloon floating maneuver.

We describe two neonates with anatomically corrected malposition of the great arteries (ACM). A 1-day-old female newborn, who had the salient clinical findings of Goldenhar syndrome, behaved like a patient with the tetralogy of Fallot. The cardiac malformations included ACM, perimembranous inlet and outlet ventricular septal defect with tricuspid valve straddling, conoventricular septal malaligement, bilateral cori without aortic-mitral continuity, pulmonary stenosis at subvalvular, valvular, and supravalvular levels, and bicuspid semilunar valves. After the procedure of left Blalock-Taussig shunt at 3 months of age, cyanosis was alleviated. The other 1-month-old male newborn, who presented with prolonged feeding, tachypnea and tachycardia, likened to a patient with the hypoplastic left heart syndrome. He had a combination of ACM, mitral stenosis, hypoplastic left atrium and left ventricle, a restrictive patent foramen ovale, ventricular septal defect, subaortic conus without aortic-mitral continuity, subaortic stenosis, and a narrow ascending aortic root. Rashkind balloon atrioseptostomy was done with limited success. He survived a Norwood procedure. Transarterial entry of the catheter, which was inverted with the aid of balloon floating maneuver, to hook the retro-aortic pulmonary artery in ACM is recommended.

Angiography↗

PubMed1998

Clinical implications of isolated double aortic arch and its complex with intracardiac anomalies.

From July 1, 1989 to June 30, 1996, a total of six patients, four male and two female, with double aortic arch (DAA) were registered. They aged 16 days to 6.5 years. There were two patients with isolated DAA, and four complicated with intracardiac anomalies. All six patients presented respiratory distress and feeding problem early in life. However, cyanosis, owing to decreased pulmonary blood flow, predominated the clinical picture in each patient having DAA intricated with tetralogy of Fallot (TOF) and pulmonary stenosis, TOF with absent pulmonary valve syndrome, and type II-A tricuspid atresia. DiGeorge syndrome was documented in one patient with TOF and pulmonary stenosis. Expiratory wheezing was remarkable in the patient with TOF and absent pulmonary valve syndrome. Mild cyanosis and heart failure was noted in one patient with ventricular septal defect (VSD), and bicuspid pulmonary valve with mild valvular stenosis. Barium esophagogram showed indentations on esophagus in five patients. Echocardiography was yielding in three infants. Four patients, two isolated and two complex DAA, survived the surgical division of the smaller left aortic arch. One-stage and two-stage operation was performed in patients having DAA intricated with VSD and TOF, respectively. The other two patients with complex DAA remained in close observation owing to the tolerance of symptoms related to intracardiac anomalies.

Aorta, Thoracic↗

PubMed1998

Usefulness of electron beam computed tomography in children with heterotaxy syndrome.

Children with heterotaxy syndrome frequently have complex cardiac and noncardiac malformations requiring detailed diagnostic evaluation for management planning. Direct delineation of these structures by electron beam computed tomography (EBCT) is validated as a means of diagnosis. From July 1995 to March 1997, 32 patients (16 girls, 16 boys) with clinically impressed heterotaxy syndrome were enrolled in this study. After evaluation by echocardiography, EBCT studies were performed. Interpretation of cardiac anomalies was performed by sequential analysis based on these cross-sectional images. The diagnoses were subsequently confirmed by angiocardiography and surgical findings. Twenty-eight patients had bilateral trifurcated bronchi, and most of these (24 of 28) did not have a spleen. Four patients had bilateral bifurcated bronchi, 2 patients had polysplenia, and the other 2 patients had a lobulated single spleen. We found that laterality could be identified by EBCT in all patients. Comparison of diagnostic yield between echocardiography, catheterization, and EBCT showed that EBCT is superior to echocardiography and catheterization in demonstration of pulmonary venous anatomy and presence of a very small rudimentary ventricle. In addition, associated visceral, bronchopulmonary, mediastinal, and intracardiac anomalies could all be clearly delineated by EBCT at the same time. Thus, EBCT is a promising complementary modality for an overall understanding of heterotaxy syndrome.

Abnormalities, Multiple↗

PubMed1998

Extracorporeal membrane oxygenation support for single lung transplantation in a patient with primary pulmonary hypertension.

Left single lung transplantation was performed under perioperative extracorporeal membrane oxygenation (ECMO) support for a patient of primary pulmonary hypertension. Continuous ECMO in this patient for one day after the transplantation decreased the pulmonary blood flow and probably served to minimize the potential complication of reperfusion edema of the graft. During this period, the ECMO was gradually weaned so that the grafted lung could adapt itself to the gradually increased blood flow through it. The patient was extubated without difficulty 2 days alter the removal of ECMO and made a smooth recovery.

Adult↗

PubMed1996

Malalignment-type ventricular septal defect in double-chambered right ventricle.

Double-chambered right ventricle (DCRV) is commonly associated with ventricular septal defect (VSD). In this study, an assessment was made of the relevance of a malalignment-type VSD to hemodynamic and morphologic features in DCRV. During an 8.5-year period, 53 patients with DCRV were enrolled after study with echocardiography, catheterization, and angiography. Patients were divided into 2 groups: group I included 40 patients, aged 3.7 +/- 3.2 years, with a malalignment-type VSD; group II consisted of 13 patients, aged 8.6 +/- 2.7 years, without a malalignment-type VSD. History of congestive heart failure in infancy was present in 21 group I and 2 group II patients (53% vs 15%, respectively, p <0.05). The mean pulmonary-to-systemic flow ratio was significantly higher in group I than in group II (1.89 +/- 0.74 vs 1.14 +/- 0.21, respectively, p <0.05). The mean pressure gradient across the right ventricular outflow tract was lower in group I than in group II (41 +/- 16 vs, 73 +/- 33 mm Hg, respectively, p <0.05). Among 42 patients who had a series of echocardiograms recorded, progression of pressure gradient was evident in 35: 28 in group I and 7 in group II. A subaortic ridge was present exclusively in 29 group I patients (73%). Prolapse of the aortic valve was present in 26 (49%): 20 group I (50%) and 6 group II (46%) patients. Aneurysm formation of the septal defect was found in 17 (43%) and 7 (54%) group I and II patients, respectively. It can be concluded that a history of congestive heart failure was more common in DCRV patients with a malalignment-type VSD. Malalignment-type VSD is significantly associated with a larger pulmonary-to-systemic flow ratio and subaortic ridge.

Adolescent↗

PubMed1996

Angiographic evidence of long-axis rotation in addition to short-axis aortopulmonary rotation: its implication in transposition of the great arteries.

To assess the pattern of aortic sinus in varied aortopulmonary rotations and its clinical implications, three aortic sinuses at the diastolic phase in true lateral view are identified in 53 angiograms of complete transposition of the great arteries recorded between 1988 and 1993. The patients with the high takeoff of the coronary arteries found at surgery and in the literature were selected for additional investigation. Six regions were defined on the horizontal plane. From left anterior 89 degrees to 61 degrees, the non-facing sinus moved toward the anterior aspect (one patient). From left anterior 60 degrees to left anterior 1 degree, the left-hand sinus moved gradually from an anterior toward a posterior location (two patients). From directly anterior 0 degree to right anterior 59 degrees, the right-hand sinus moved from posterior toward an anterior position (30 patients). From right anterior 60 degrees to right posterior 105 degrees, the non-facing sinus moved posteriorly (20 patients). On approaching directly anterior 0 degree and toward right anterior 60 degrees, the left-hand sinus was the lowest in anterior transposition of the great arteries instead of the non-facing sinus, as in left anterior 90 degrees and in posterior transposition of the great arteries. High takeoff occurred commonly above the lowest left-hand sinus in anterior transposition of the great arteries (2 cases here and 5 in the literature, 100%). In conclusion, aortopulmonary rotations about the short and long axes were both evident on identification of the aortic sinus in various rotations. The aortic sinus did not rotate along the long-axis in anterior transposition of the great arteries, thus making the left-hand sinus, the lowest of this group, vulnerable to the high takeoff of the coronary arteries in anterior transposition of the great arteries.

Aorta↗

PubMed1996

Studies on epoxy compound fixation.

Bioprostheses derived from collagenous tissues have to be fixed and subsequently sterilized before they can be implanted in humans. Clinically, the most commonly used fixative is glutaraldehyde. However, the tendency for glutaraldehyde to markedly alter tissue stiffness and promote tissue calcification are well-recognized drawbacks of this fixative. To address the deficiencies with the glutaraldehyde-fixed tissue, a new fixative, epoxy compound, was used to fix biological prostheses. The study was undertaken to investigate the fixation rates and crosslinking densities of biological tissues fixed with various epoxy compounds. These epoxy compounds are different in their chemical structures. Glutaraldehyde was used as a control. The fixation rates and crosslinking densities of the fixed tissues were determined by measuring their fixation indices and denaturation temperatures, respectively. Generally, the epoxy-fixed tissues were more pliable than the glutaraldehyde-fixed one. Furthermore, the tissues fixed with monofunctional epoxy compound were more pliable than those fixed with multifunctional epoxy compounds. With increasing pH or temperature, the fixation rate of epoxy compound increased. However, the number of epoxide functional groups did not seem to affect the fixation rate of the epoxy compound. The fixation rate of glutaraldehyde was faster than that of epoxy compounds. Additionally, the crosslinking density of the glutaraldehyde-fixed tissue was greater than that of the epoxy-fixed counterparts. Moreover, it was noted that the denaturation temperatures of the tissues fixed with glutaraldehyde or multifunctional epoxy compounds were significantly higher than the fresh ones (p < 0.05), while that fixed with monofunctional epoxy compound stayed roughly the same throughout the entire fixation process (p > 0.05). The results obtained in this study may be used to optimize the fixation process for developing bioprostheses fixed with epoxy compounds.

Animals↗

PubMed1996

Efficacy of ultrafiltration in removing inflammatory mediators during pediatric cardiac operations.

BACKGROUND: Conventional and modified ultrafiltration was used in pediatric cardiac operations to reduce volume overload and total body water. The purpose of this study was to compare the efficacy of these techniques in removing inflammatory mediators during cardiopulmonary bypass. METHODS: Fifty pediatric patients undergoing cardiac operations were randomized into a modified or conventional ultrafiltration group. Blood samples were obtained before and after ultrafiltration to assess the plasma concentrations of leukocyte elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8. RESULTS: Except for plasma concentrations of tumor necrosis factor-alpha in the modified ultrafiltration group, the plasma concentrations of all the mediators measured increased after ultrafiltration in both groups of patients. The volume of ultrafiltrate and the total amounts of tumor necrosis factor-alpha and interleukin-6 removed by ultrafiltration were significantly greater in the modified group. The concentrations of mediators in the ultrafiltrate and the ratio of ultrafiltrate to plasma concentrations of the mediators did not differ between the groups. Ultrafiltration was more efficient in removing tumor necrosis factor-alpha than the other mediators. CONCLUSIONS: The efficacy in removing the inflammatory mediators generated during cardiopulmonary bypass did not differ between modified and conventional ultrafiltration.

Analysis of Variance↗

PubMed1996

Anomalous pulmonary venous pathway traversing pulmonary parenchyma. Diagnosis and implication.

STUDY OBJECTIVES: To describe four patients having total anomalous pulmonary venous connection with an intrapulmonary vertical vein, rendering difficulty in diagnosis and surgery. SETTING: a tertiary referral center. PATIENTS AND METHODS: By reviewing medical records, 4 of 25 patients with right atrial isomerism and total anomalous pulmonary venous connection were identified to have an intrapulmonary vertical vein. All four patients underwent echocardiography, catheterization, and angiography. One underwent MRI. Two underwent open-heart surgery and one received a modified Blalock-Taussig shunt. RESULTS: Right atrial isomerism was present in all four patients. On chest x-ray films, an abnormal shadow resembling scimitar syndrome was seen in two patients. Imaging the vertical vein was unsuccessful with an echocardiogram in all four patients. The intrapulmonary course of the vertical vein was depicted with a pulmonary venogram in two patients and with magnetic resonance in one patient. The intrapulmonary segment remained undetected until autopsy in one patient. All four patients died. At autopsy, the pulmonary venous confluence was hypoplastic in all four hearts. The vertical vein was buried in pulmonary parenchyma and drained to superior vena cava with significant obstruction. CONCLUSION: In the presence of right atrial isomerism and total anomalous pulmonary venous connection, there may be an intrapulmonary pulmonary venous connection that may be obstructed. Anastomosing the pulmonary venous confluence to the atrium may be difficult because of hypoplasia of the pulmonary venous confluence.

Anastomosis, Surgical↗

PubMed1996

Pentalogy of Cantrell corrected by one-stage repair.

Pentalogy of Cantrell (POC), is a rare congenital defect associated with five ventral midline abnormalities and high mortality. We report a 2,788 g female infant with partial repair of POC in the neonatal stage. This consisted of repairing the omphalocele, plicating the eventrated diaphragm and placing the heart into the thoracic cavity by fixing the pericardium to the ventral side of the diaphragm. She was well 6 months after surgery.

Abnormalities, Multiple↗

PubMed1996

Continuous monitoring of venous oxygen saturation in critically-ill infants.

A 4-French gauge Opticath catheter, inserted into a neonate's right atrium through the right internal jugular vein, can be used to continuously monitor venous blood oxygen saturation in the right atrium. This method instantly detects subtle changes in cardiopulmonary function in small infants and neonates and enables the appropriate treatment to be given in cases of critical infantile and neonatal cardiopulmonary deterioration. This report discusses four neonatal and infantile patients who underwent continuous monitoring of venous blood oxygen saturation in the right atrium. Continuous monitoring allowed appropriate treatment to be given earlier compared to conventional monitoring methods of blood pressure and heart rate.

Cardiac Catheterization↗

PubMed1995

Surgical treatment of complete atrioventricular septal defect associated with tetralogy of Fallot.

The combination of complete atrioventricular septal defect (AVSD) and tetralogy of Fallot (TF) was reported to occur in less than 2% of patients undergoing repair of TF. From September 1981 to November 1989, five consecutive patients with such combination underwent total correction at National Taiwan University Hospital. Their age ranged from 3.8 years to 6.3 years. Two cases were associated with Down's syndrome. All interventricular communications were repaired by combined transatrial and transventricular approach and a separate pericardial patch was used to repair the interatrial communication. The transannular patch (TAP) was not used in one case; of the four cases with TAP, a pericardial monocusp was mounted in one of them. There was one hospital mortality, and one late death. Both were related to intractable right heart failure. We conclude that total repair of this anomaly could be accomplished after 3 years of age provided there is thorough awareness of anatomical features and avoidance of right heart failure.

Child↗

PubMed1995

Evolution of coronary artery pattern according to short-axis aortopulmonary rotation: a new categorization for complete transposition of the great arteries.

OBJECTIVES: We studied the correlation between coronary artery pattern and aortopulmonary rotation in complete transposition of the great arteries. BACKGROUND: Classifications of the coronary arteries in complete transposition are puzzling and incomplete. METHODS: Coronary artery anatomy and relation of the great arteries were identified at angiography, echocardiography, surgical intervention or autopsy in 76 patients with complete transposition from 1988 to 1993. Five main types (type 0 and Shaher types 1,2,4 and 9) and their similar variants of epicardial configuration were categorized into five patterns (O, I, II, IV and IX). In addition, data from 568 cases from published reports were collected for analysis. RESULTS: As the aorta rotated from a left anterior to a directly anterior location relative to the pulmonary trunk, the left anterior descending coronary artery arose from the left-hand sinus together with the right coronary artery (type 0, one case decreased to no cases); then it gradually shifted to the left to have the same origin as the left circumflex coronary artery from the right-hand sinus (type 1, 10 cases increased to 146, p < 0.0003). When the aorta rotated farther clockwise from directly anterior to right anterior (type 1, 146 cases increased to 235; type 2, 9 cases increased to 50, p < 0.0006) or from right anterior to right lateral (type 1, 235 cases decreased to 6 cases; type 2, 50 cases decreased to 20, p < 0.00000), the left circumflex coronary artery tended to move retropulmonically and originated from the left-hand sinus with the right coronary artery (type 2). When the aorta moved from right anterior to right lateral (type 2, 50 cases decreased to 20; type 4, 13 cases increased to 14, p < 0.031) or from right lateral to right posterior (type 2, 20 cases decreased to 1; type 4, 14 cases increased to 16, p < 0.0003), the right coronary artery shifted to the right-hand sinus anteaortically to join the left anterior descending coronary artery (type 4). Finally, the left anterior descending coronary artery combined with the left circumflex coronary artery (type 9, 12 cases increased to 21, p = 0.407) to become the usual pattern for normally related great arteries. Eta-square analysis showed that the evolution from pattern O to IX was dependent on clockwise aortopulmonary rotation. CONCLUSIONS: The coronary arteries in complete transposition of the great arteries can be classified into five patterns and their evolution deduced on the basis of aortopulmonary rotation. Dependence of coronary artery type on aortopulmonary rotation made it possible to anticipate the coronary pattern from the relation of the great arteries in transposition.

Adolescent↗

PubMed1995

Implication of anterior septal malalignment in isolated ventricular septal defect.

OBJECTIVE: The aim was to define the long term prognosis of isolated ventricular septal defect (VSD) with anteriorly malaligned outlet septum. DESIGN: Cohort study. SETTING: University hospital, tertiary medical care centre. PATIENTS: Between July 1986 and June 1993, 63 patients were studied with an isolated VSD and anteriorly malaligned outlet septum (59 perimembranous; 4 muscular outlet). MAIN OUTCOME MEASURES: The diagnosis of septal malalignment, aneurysmal transformation, right ventricular obstruction, subaortic ridge, and aortic valve prolapse was based on echocardiographic criteria, then confirmed by angiography in 33 patients and by surgery in 28. An actuarial curve for each event was obtained by Kaplan-Meier non-parametric analysis and the significance was examined by log-rank test. RESULTS: Aneurysmal transformation decreased the size of the VSD in 52% of the patients, but was also associated with the appearance of subaortic ridge (p < 0.05). Progressive obstruction in the right ventricle was observed in 51%, more often in those without aneurysmal transformation (p < 0.05). Aortic valve prolapse was quite common whether or not aneurysmal transformation occurred (33% and 23%, respectively). This was attributed to the location of the VSD and the anterior malalignment of the outlet septum. Surgery was performed in 28 patients at a median age of 50 months because of significant left to right shunt (n = 5), or the development of obstruction in right ventricle (n = 9), aortic valve prolapse (n = 3), or combinations (n = 11). The presence of subaortic ridge per se was not considered to be a surgical indication. CONCLUSIONS: Anteriorly malaligned VSDs have variable presentation. Careful echocardiographic evaluation is needed to identify various combinations of progressive right ventricular obstruction, aneurysmal transformation, subaortic ridge, or aortic valve prolapse. In extreme cases a patient may have a pathology complex comprising right ventricular outflow obstruction, subaortic ridge, aortic valve prolapse, and anteriorly malaligned VSD.

Child, Preschool↗

PubMed1995

Electrophysiological properties of dual atrioventricular nodes in patients with right atrial isomerism.

There are reports that in right atrial isomerism the conduction system has paired sinus nodes and paired atrioventricular nodes. Electrophysiological studies were performed in two patients with right atrial isomerism. One patient had a delta wave on the surface electrocardiogram without tachycardia attacks. The other, who did not have manifest pre-excitation, had recurrent narrow QRS tachycardia. Electrophysiological studies suggested the presence of dual atrioventricular nodes. Only unidirectional atrioventricular or ventriculoatrial conduction was demonstrated for these dual atrioventricular nodes even after infusion of isoprenaline. It is suggested that unidirectional conduction may be a common property of the dual atrioventricular nodes in right atrial isomerism and that the absence of retrograde ventriculoatrial conduction protects the patients against tachycardia.

Atrioventricular Node↗

PubMed1995

Cerebral embolism from the thrombus in the atrioventricular septal aneurysm.

Atriventricular septal aneurysm is a rare finding. Thrombus within the atrioventricular septal aneurysm has never been reported. Here, we report a girl with sudden-onset hemiparesis. Magnetic resonance imaging of the patient's head revealed a lesion at the right basal ganglion. Cerebral infarction was impressed. A series of examinations was performed to find the source of the cerebral embolism. Transthoracic echocardiography further showed a thrombus in the aneurysm. A subsequent operation revealed a fresh thrombus in the aneurysm. The presence of an anatomic substrate such as this might justify anticoagulation treatment or even surgical intervention before thromboembolism occurs.

Adult↗

PubMed1995

[The first successful case or Norwood operation for hypoplastic left heart syndrome in Taiwan].

UNLABELLED: Hypoplastic left heart syndrome is not infrequently seen in Taiwan, but all died previously. An 8 day-old-male baby suffering from hypoplastic left heart syndrome was transferred to our hospital after cardiopulmonary resuscitation. Oral prostaglandin E2 was used to maintain ductal patency and carbon dioxide was used through a respirator to control his pulmonary blood flow. He underwent Norwood operation at age 15 days under deep hypothermia and circulatory arrest. The postoperative course was smooth and occasional tachypnea was controlled by carbon dioxide inhalation through a mask. A follow up echocardiogram showed patent shunt and neoaortic pathway, good interatrial communication and mild tricuspid regurgitation. The baby survived and has fared well 2 years postoperatively. CONCLUSION: We recommend carbon dioxide manipulation before and after the Norwood operation for hypoplastic left heart syndrome with increased pulmonary blood flow uncontrollable by the respirator.

Carbon Dioxide↗