Biomedical subjects

C W Chiang

Publications and source records attributed to C W Chiang.

At least 55 records · Page 3Linked to original sources

PubMed1997

Video-assisted thoracoscopic operation for interruption of patent ductus arteriosus in adults.

BACKGROUND: Patent ductus arteriosus (PDA) is a frequent congenital heart disease encountered in premature neonates, infants, and children. Video-assisted endoscopic techniques have been used in PDA interruption since 1993. Almost all the experiences are in pediatric patients. Applications in adults with PDA have been limited. METHODS: We report our experience of video-assisted thoracoscopic surgical ligation of PDA in adults. From August 1995 to January 1996, 60 patients with PDA were operated on with a video-assisted thoracoscopic technique. Twelve adults were identified with mean age of 30 years (range, 20 to 57 years). With the patient under general anesthesia and double-lumen endotracheal intubation, two 5-mm holes were made in the left lateral chest wall. Another 4-cm incision was made in the left third intercostal space for manipulation, dissection, and ligation. Conventional surgical instruments were used except an endoscopic grasper and an endoscopic tube that connected to a video camera. The surgical procedure was viewed on a video screen. Transesophageal echocardiography was used for monitoring during PDA ligation. RESULTS: All patients had successful ligation of the PDA. There was no surgical mortality, but there was one morbidity; transient recurrent nerve injury, which recovered 3 months later. Ten patients were extubated in operative room and 2 patients were extubated 2 hours after the operation. Tube thoracostomy was performed in the first 2 cases; it was omitted thereafter. No patients needed narcotic to control chest pain. Postoperative follow-up by echocardiography showed faint ductal flow in 1 patient without any murmur. All patients were discharged within 3 days after the operation. CONCLUSIONS: Our experience suggests that with refinement of instruments and surgical technique, video-assisted thoracoscopic surgical ligation can be safely applied not only in pediatric patients, but also in adults with PDA.

Adult↗

PubMed1997

Video-assisted coronary artery bypass grafting during hypothermic fibrillatory arrest.

BACKGROUND: Hypothermic fibrillatory arrest without aortic cross-clamping is a technique for quieting the heart during coronary artery bypass grafting. This report reviews the preliminary results with this technique in 4 patients having video-assisted coronary artery bypass grafting. METHODS: Four male patients 28.5 to 64.5 years old (mean age, 45.4 years) underwent operation for unstable angina. With video-assisted techniques, coronary artery bypass grafting was performed through a left anterior minithoracotomy with femoral-femoral cardiopulmonary bypass without cross-clamping the aorta. The myocardium was protected by continuous coronary perfusion during hypothermic fibrillatory arrest. RESULTS: A left internal thoracic artery graft was anastomosed to the left anterior descending coronary artery in each patient. The posterior descending branch of the right coronary artery was grafted with a pedicled right gastroepiploic artery in 1 patient. The duration of cardiopulmonary bypass was 72 to 127 minutes (mean duration, 92 +/- 21 minutes). The postoperative course of each patient was uneventful. Follow-up (range, 3.9 to 5.8 months; mean follow-up, 4.9 months) was complete for all patients. There were no late deaths. Coronary angiography showed patent grafts. All patients were in New York Heart Association functional class I or II (mean class, 1.25). CONCLUSIONS: Hypothermic fibrillatory arrest is a simple and effective method of quieting the heart, thereby providing a motionless operative field for video-assisted coronary artery bypass grafting.

Adult↗

PubMed1997

Cardiac tamponade in Taiwan.

We retrospectively reviewed all of the patients who were treated for cardiac tamponade at Linkou Chang Gung Memorial Hospital between January 1991 and December 1995. There were a total of 112 patients (57 males, 55 females) with a mean age of 51 +/- 14 years (53 +/- 15, 49 +/- 13, respectively). Dyspnea was the most common complaint (85%). The mean blood pressure was 129 +/- 24/78 +/- 17 mmHg, and only 8% had a systolic blood pressure of less than 90 mmHg. Sinus tachycardia was the most frequent electrocardiographic finding (72%, 62/86). Diffuse low voltage was noted in 35% (30/86) of the patients and electrical alternans was seen in 17% (15/86). The mean volume of pericardial effusion was 610 +/- 263 ml. Sixty-five percent of the pericardial effusions were bloody, 31% were serosanguineous, 2% were purulent and 2% were chylous. Overall, 54.5% of the patients had malignant diseases. Of the 61 patients who died, 79% had malignancies. Thirty-five (57%) of these 48 patients had lung cancer. The mean survival time from emergent pericardiocentesis was 3.4 months. In conclusion, non-traumatic cardiac tamponade had a poor prognosis because most patients had malignant etiologies. There is still no definitive treatment for recurrent malignant pericardial effusion-induced cardiac tamponade. Percutaneous pericardiocentesis as clinically required may be the most appropriate treatment, since it is questionable whether such subjects should be subjected to the unnecessary pain and suffering associated with an operative procedure, considering their short mean survival time.

Adolescent↗

PubMed1997

Thrombectomy for left ventricular protruding thrombi in a patient with dilated cardiomyopathy.

Left ventricular thrombus is one source of cardiogenic embolism. The protruding, mobile type is the highest risk subgroup but is rarely encountered. Thrombectomy is one choice of therapy, and variously recommended based primarily on the experience with myocardial infarction. We report a rare case of successful left ventricular thrombectomy for two protruding, mobile thrombi in a patient with idiopathic dilated cardiomyopathy in order to prevent repeat embolization.

Adult↗

PubMed1997

Rhabdomyolysis, acute renal failure and hepatopathy induced by lovastatin monotherapy.

Lovastatin is a popular drug for the treatment of hypercholesterolemia. Few serious complications are associated with its use although rhabdomyolysis with renal failure has been reported when lovastatin is combined with cyclosporine or other drugs following transplantation. We report the case of a patient who developed hepatopathy and rhabdomyolysis accompanied by acute renal failure after 4 weeks of lovastatin monotherapy. The pathogenesis and treatment of these complications are also discussed.

Acute Kidney Injury↗

PubMed1997

Cardiac perforation and tamponade induced by external cardiac massage: a case report.

A 76-year-old woman suffered from sudden loss of consciousness while sitting in a chair. She was sent to a local hospital and found to be in shock. After a brief period of external cardiac massage, she was transferred to our hospital. In our emergency department she was lethargic with cool, clammy extremities. Her blood pressure dropped from 113/53 mmHg on arrival to 72/42 mmHg 2 hours later. Echocardiography showed massive pericardial effusion, fair left ventricular contractility and no abnormal segmental motion. The echocardiographic appearance suggested fibrin-like substance in the pericardial space, which was felt to indicate the presence of blood. Enhanced chest computerized tomography showed extravasation of contrast medium from the right ventricular outflow tract. At surgery, a small perforation was found at the infundibular area of the right ventricle, and a total of 500 mL of blood had accumulated in the pericardial space. She was discharged 7 days postoperatively, having made an uneventful recovery. External cardiac massage may cause cardiac disruption, and this should be considered in patients who have secondary hemodynamic instability following successful cardiopulmonary resuscitation.

Aged↗

PubMed1997

Transluminal coronary angioplasty and stenting in a patient with single coronary artery and acute myocardial infarction.

An isolated single coronary artery is a rare congenital anomaly with an incidence of 0.03% to 0.4% and can present additional hazards such as myocardial ischemia, infarction, or sudden death in individuals with atherosclerotic changes in this artery. Herein, we report an acute anterior and inferior wall infarction in a 61-year-old male patient with the right coronary artery arising as a branch of the left coronary artery. Selected coronary angiography showed a 90% stenosis in the left anterior descending artery proximal to the origin of the right coronary artery. The patient underwent successful percutaneous transluminal coronary angioplasty and stenting without compromising the flow to the anomalous right coronary artery. There has been no previous reports of percutaneous transluminal coronary angioplasty and coronary stenting in a patient with this anomaly.

Angioplasty, Balloon, Coronary↗

PubMed1996

The G1691A mutation of the coagulation factor V gene (factor V Leiden) is rare in Chinese: an analysis of 618 individuals.

To understand the allele frequency of the G1691A mutation of the coagulation factor V gene (factor V Leiden) in Chinese, 618 Chinese individuals, including 54 cases with venous thrombosis, were analyzed. Only one case in the control group was heterozygous for the 1691G allele and the 1691A allele. Our data suggest that the factor V Leiden is rare in Chinese.

Alleles↗

PubMed1996

Video-assisted mitral valve operations.

BACKGROUND: Video-assisted endoscopy has been applied frequently in the management of a variety of surgical diseases. However, it has rarely been applied in mitral valve surgery. METHODS: We report 2 patients who received emergency operations for thrombosis of a mitral prosthesis (patient 1, a 68-year-old man) and acute mitral regurgitation due to rupture of anterior chordae (patient 2, a 75-year-old woman). They both had severe congestive heart failure. Cardiogenic shock was noted in patient 2. The mitral valve was approached through a right anterior minithoracotomy with the aid of an endoscope by means of projected images on the video monitor under femorofemoral cardiopulmonary bypass. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest. The left atrium was entered posterior to the interatrial groove. Thrombectomy and mitral valve repair were performed successfully. RESULTS: The duration of extracorporeal circulation was 204 and 147 minutes, respectively. Both patients recovered from the operation rapidly with uneventful postoperative courses. CONCLUSIONS: Our preliminary results suggest that video-assisted endoscopic cardiac surgery is technically feasible and could be performed in the milieu of open heart surgery.

Aged↗

PubMed1996

Video-assisted cardiac surgery in closure of atrial septal defect.

BACKGROUND: Video-assisted endoscopy has been applied in the management of a variety of intrathoracic vascular lesions. Here we report its use in the correction of intracardiac congenital defects. METHODS: Eight patients (3 male and 5 female) underwent operation for closure of an atrial septal defect. The patients ranged in age from 2.0 to 60.9 years (mean, 19.2 +/- 19.0 years). The patients weighed 11 to 66 kg (mean, 41.3 +/- 23.5 kg). The ratio of pulmonary blood flow to systemic blood flow ranged from 2.0 to 6.0 (mean, 3.4 +/- 1.3). The mean pulmonary artery pressure was 19.7 +/- 4.0 mm Hg (range, 13 to 24 mm Hg). The operations were performed through a right anterior minithoracotomy and guided by video-assisted endoscopic techniques under femorofemoral or femoral-right atrial extracorporeal circulation. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest (rectal temperature, 22.0 degrees +/- 2.0 degrees C). Transesophageal echocardiographic monitoring was maintained during the operations. The right atrium was entered after pericardiotomy. Primary closure of the defect was performed successfully in all patients. Conventional nondisposable instruments were used for dissection, grasping, suturing, and hemostasis. RESULTS: The durations of extracorporeal circulation and operation ranged from 47 to 126 minutes (mean, 80 +/- 31 minutes) and from 2.2 to 4.5 hours (mean, 3.1 +/- 0.8), respectively. All patients recovered from the operation rapidly with an uneventful postoperative course. CONCLUSIONS: Our experience demonstrates that video-assisted cardiac surgery is technically feasible and can be used with excellent results for the repair of congenital heart defects in general.

Adolescent↗

PubMed1996

Video-assisted cardiac surgery. Preliminary experience in reoperative mitral valve surgery.

OBJECTIVES: Video-assisted endoscopic techniques had been applied in the surgical correction of patent ductus arteriosus, vascular ring, or coronary artery disease. However, it has been used only recently in the correction of reoperative mitral valve lesions. DESIGN: Video-assisted cardiac operations were performed on four patients who had received surgical interventions on their mitral valves and needed emergent reoperation. PATIENTS: Four patients (3 men and 1 woman) received emergency surgery from September to December 1995 for thrombosis of mechanical mitral prosthesis (2 patients) and severe mitral regurgitation with previously failed mitral valve repair (2 patients). Six previous operations had been performed on these mitral valves. Patient ages ranged from 26.7 to 68.1 years (mean, 47.3 years). Preoperatively, acute pulmonary edema occurred in two patients, cerebral emboli occurred in one patient, and sepsis was found in one patient. Mechanical ventilatory support was used in two patients before operation. INTERVENTION: The operations were performed through right anterior minithoracotomy, guided by video-assisted endoscopic techniques with femoro-femoral extracorporeal circulation. The operative procedures were thrombectomy of mitral prosthesis in two patients, mitral valve repair in one patient, and mitral valve replacement in one patient. RESULTS: The duration of extracorporeal circulation was 166 to 320 min (222 +/- 67 min) and the operation time was 4.6 to 6.8 h (6.1 +/- 1.0 h). All patients recovered from the operations rapidly with uneventful postoperative courses except 1 patient who had sepsis preoperatively and died 2 months later. CONCLUSION: Our experience demonstrates that video-assisted cardiac surgery is technically feasible and could be performed in reoperation of the mitral valve.

Adult↗

PubMed1996

Anticholinergic overdose induced torsade de pointes successfully treated with verapamil.

An 18-year-old schizophrenic female was recently treated after overdosing on trihexyphenidyl, thioridazine and an unknown antidepressant. On presentation to a local hospital, she was cyanotic with dilatated pupils and in acute respiratory failure. She was intubated prior to transfer. While in our Emergency Department, she exhibited occasional premature ventricular contractions which later became intermittent torsade de pointes. As this was an anticholinergic overdose we infused sodium bicarbonate in an attempt to increase protein binding, hoping to decrease the concentration of toxic metabolites. We also tried to suppress the dysrhythmia by infusing magnesium. The potassium level was borderline low so a supplemental infusion was initiated. Defibrillation was attempted. To try to shorten the action potential duration by activating the K+ channel, an isuprel infusion was also attempted. All methods failed. The patient fluctuated between an irregular sinus rhythm with prolonged QT interval and pulseless torsade de pointes for almost 24 hours. At all times, she responded appropriately to pain. Finally we attempted blockade of the calcium channel using verapamil with dramatic results. Each single bolus (0.1 mg/kg) successfully converted the patient back to sinus rhythm for some 15-20 minutes before the torsade recurred. After the initiation of a continuous verapamil infusion (0.005 mg/kg/hr), the patient remained in stable sinus rhythm. Verapamil proved highly effective in this patient with an anticholinergic overdose induced dysrhythmia.

Adolescent↗

PubMed1996

Metastatic colonic carcinoma with intracavitary right ventricular outflow tract obstruction and cardiac tamponade: a case report.

Intracavitary metastasis causing right ventricular outflow tract (RVOT) obstruction is very rare. Combination of cardiac tamponade with RVOT obstruction due to intracavitary metastasis has never been reported in the literature. Herein, we report a case of colonic carcinoma with sudden onset of severe dyspnea. Echocardiography detected cardiac tamponade as well as a huge intracavitary mass obstructing the RVOT. Pericardiocentesis and surgical resection of the right ventricular mass were performed but the patient died during operation. Thus, the combination of intracavitary RVOT obstruction and cardiac tamponade in a patient with carcinoma suggests extensive myocardial and pericardial involvement with a poor prognosis.

Cardiac Tamponade↗

PubMed1996

[Pulmonary embolism: clinical and laboratory features in 62 patients].

The clinical and laboratory features in 62 patients with acute pulmonary embolism were analized. There were 26 males, and 36 females with mean age of 63 +/- 11 (range 37 to 90). The clinical symptoms include: dyspnea (92%), chest pain and/or chest tightness (65%), cough (50%), wheezing (29%), leg swelling (32%), hemoptysis (24%), syncope (18%), leg pain (10%). Clinical signs include: tachypnea (respiratory rate > or = 20 per minute) (79%), tachycardia (37%), deep vein thrombosis (29%), cyanosis (8%), fever (> 38.5 degrees C) (2%). The possible predisposing factors include: immobilization (18%), surgery (5%), deep vein thrombosis, ever(5%), malignancy (5%), pulmonary embolism, ever (3%). Arterial blood gas analysis (while patients breathed room air) revealed mean PH of 7.46 +/- 0.06, mean PO2 of 64.5 +/- 12.1 mmHg, mean PCO2 of 35.3 +/- 4.6 mmHg, mean Alveolar-arterial O2 difference of 36.5 +/- 16.6 mmHg. The electrocardiographic changes include; nonspecific ST-T change (61%), sinus tachycardia (20%), S1Q2T3 pattern (15%), atrial fibrillation (16%), incomplete right bundle branch block (10%), complete right bundle branch block (8%), atrial premature contraction (7%), paroxysmal supraventricular tachycardia (2%). The chest x-ray findings include: cardiomegaly (48%), regional hypovascularity (31%), atelectasis (5%), pleural effusion (5%), wedge-shaped infiltrate (3%), elevated diaphragm (6%). Venous plethysmography was performed in 49 of 62 patients. Of these 49 patients, 28 patients revealed positive finding. Of these 28 patients with positive finding, 18 patients had clinical evidence of deep venous thrombosis. The in-hospital mortality rate was 10% (6/62).

Aged↗

PubMed1995

[Angioplasty for subclavian artery stenosis: report of two cases].

We present our experience of percutaneous transluminal angioplasty (PTA) in the treatment of subclavian artery stenosis in two patients. One patient was a 66-year-old asymptomatic man. His left arm systolic blood pressure was 40 mmHg lower than that of his right arm. He had irregular segmental stenotic lesions (50% to 80%) at the proximal portion of the left subclavian artery. PTA was attempted via the left brachial artery. After the procedure, the stenotic lesion seemed totally dilated and his left arm systolic blood pressure was 8 mmHg lower than that of his right arm. Restenosis of the left subclavian artery was noted four months after the procedure. The second patient was a 51-year-old man with symptoms of intermittent dizziness, nausea and vertigo. His left arm systolic blood pressure was 30 mmHg lower than that of his right arm. He had 43% diameter stenotic lesion at the proximal portion of the left subclavian artery. PTA was attempted via right femoral artery. After the procedure, the stenotic lesion seemed markedly dilated and his left arm systolic blood pressure was 14 mmHg lower than that of his right arm. He is well three years post-procedure without evidence of restenosis.

Aged↗

PubMed1995

Multiplane transesophageal echocardiography in traumatic aortic dissection: a case report.

We report a case of a 23 year old male who suffered a traffic accident and had a suspicious widening of the mediastinum on chest x-ray. Computed tomography (CT) failed to demonstrate an aortic dissection. Due to the mechanism of injury and chest X-ray findings, we decided to perform a multiplane transesophageal echocardiogram (MTE). This revealed an aortic dissection of less than one centimeter in length and good heart function. Due to CT evidence of hemoperitoneum, the patient received an emergent laparatomy. A liver laceration and jejunal perforation were found and repaired. An intraabdominal abscess developed, which led to sepsis, multiple organ failure and ultimately death. MTE was used to monitor the status of the dissection and adequacy of heart function during his intensive care unit stay. The dissection extended to 4 cm in length by the second week and then remained stable. There was no thrombus formation within the false lumen by the third month. While the patient unfortunately died from complications related to his abdominal injuries, MTE not only diagnosed the traumatic aortic dissection when CT failed, but allowed easy monitoring of both the rate of extension and the flow patterns within the false lumen. This made prognostication and treatment planning much easier.

Adult↗

PubMed1994

Long-term results of polytetrafluoroethylene mitral annuloplasty.

Prosthetic rings are customarily used for mitral annuloplasty to plicate and reinforce the annulus and keep the annulus from further dilating. From July 1984 to March 1992, mitral annular plication using polytetrafluoroethylene (PTFE) graft material was performed on 73 patients (age range, 15 to 69 years; mean, 35.7 years) with mitral regurgitation. The cause of the mitral regurgitation was rheumatic in 50.7% and degenerative in 36.9% of the patients. After other repair procedures on the mitral valve apparatus had been performed, a PTFE graft (3 mm) was tailored to the length of the free edge of the anterior leaflet and then inserted at the posterior part of the mitral annulus between the commissures. The operative mortality was 2.7%. Follow-up ranged from 0.7 to 8.5 years (mean, 5.6 years). Postoperative echocardiography confirmed that 94.2% of the survivors had either no or only mild mitral regurgitation with a large mitral valve area (2.7 +/- 0.3 cm2) and almost no pressure gradient across the mitral valve or left ventricular outflow tract. Two patients successfully underwent redo PTFE mitral annuloplasty. Two patients died, one 15 and the other 20 months later, due to myocardial failure, with no mitral regurgitation. The event-free survival rate was 90% +/- 4% at 8 years. We conclude that PTFE mitral annuloplasty is an effective procedure that yields good long-term results.

Adolescent↗

PubMed1994

Comparisons between female and male patients with mitral stenosis.

OBJECTIVE: To compare Doppler, echocardiographic, and clinical variables in female and male patients with mitral stenosis. DESIGN: Observational study in consecutive patients with mitral stenosis of cross sectional and Doppler echocardiographic and clinical variables and a retrospective search for a history of systemic embolism. SETTING: A medical centre with 3000 beds, serving both urban and rural populations. PATIENTS: 500 consecutive patients with an echocardiographic mitral valve area of 2 cm2 or less. 331 (66.2%) were female and 169 (33.8%) male (mean (SD) ages of 49 (13) and 48 (14) respectively). MAIN OUTCOME MEASURES: Mitral valve areas by echocardiographic planimetry and Doppler pressure half-time method, peak early diastolic mitral velocity and pressure gradient, echocardiographic score of mitral valve, left atrial end systolic diameter, frequency of left atrial thrombus and smoky echoes as well as various valve lesions detected with Doppler and echocardiography, cardiac rhythm, symptomatic functional class of heart failure, and history of systemic embolism. RESULTS: The prevalence of significant tricuspid (22% v 9%, P < 0.001) and pulmonary regurgitation (5% v 1%, P = 0.018) was higher in the female patients than in the male patients. Female patients also had a higher peak regurgitant velocity (3.2 (0.7) v 2.9 (0.7) m/s, P = 0.007) and pressure gradient (41 (21) v 36 (19) mm Hg, P = 0.010) across the tricuspid valve. However, the male patients had a higher echocardiographic score (9.7 (2.4) v 7.0 (2.3), P < 0.001) and a smaller Doppler-derived mitral valve area (0.9 (0.4) v 1.0 (0.4) cm2, P = 0.027). There were no differences between the female and the male patients in mitral valve area measured by planimetry, peak early diastolic mitral velocity and pressure gradient, and left atrial end systolic diameter or in the prevalence of atrial fibrillation, left atrial thrombus, left atrial smoky echoes, significant aortic stenosis, aortic regurgitation, or heart failure of New York Heart Association class III or IV. CONCLUSIONS: Female patients not only had a higher prevalence of mitral stenosis but also had a higher prevalence of associated tricuspid and pulmonary regurgitation along with a higher velocity and gradient of tricuspid regurgitation. The echocardiographic score was higher in male patients, however. These findings suggest that the pathophysiology of mitral stenosis is different in the two sexes and that gender should be taken into account when therapeutic strategies are formulated.

Echocardiography↗