Biomedical subjects

Angie C Y Ho

Publications and source records attributed to Angie C Y Ho.

7 recordsLinked to original sources

PubMed2006

Evaluation of the longitudinal contraction of the ventricle septum in patients undergoing off-pump coronary artery bypass graft surgery by strain rate imaging.

BACKGROUND: Strain rate (SR) imaging is an emerging technique for assessing myocardial systolic and diastolic functions. This technique can provide assessment in real time and color mapping; it also can detect ischemia at its earlier stages in comparison with visual estimation of wall motion with other techniques. METHODS: This study group consisted of 9 patients undergoing elective coronary artery bypass graft (CABG) surgery. After general anesthesia with sevoflurane (end-tidal 1.8%) in air/oxygen mixture, a complete transesophageal echocardiography (TEE) study was performed with an ultrasound machine. Myocardial wall strain rate imaging was then preformed off-line using a customized computer software (Echopac, Windows 2000 version 2.1, General Electric) running on a Compaq P4 computer. The experimental protocol was divided into 6 parts: (1) T1: 30 minutes after general anesthesia completed, (2) T2: after opening the sternum and pericardium, (3) T3: left anterior descending coronary artery(LAD) snared for the preparation of ischemic pre-conditioning (SLAD), (4) T4: after anastomosing left internal mammary artery (LIMA) on LAD, (5) T5: before closing the sternum and pericardium and (6) T6: after closing the sternum and pericardium. RESULTS: From strain rate imaging, peak systolic SRs were reduced or inverted over LAD perfused area during the SLAD period. In apical segments, peak systolic SR changed from -0.45 +/- 0.48 to 0.42 +/- 0.63 (P < 0.05), whereas peak diastolic SR changed from 0.34 +/- 0.61 to -0.80 +/- 1.08 (P < 0.05). In the middle septum, peak systolic SR changed from -0.67 +/- 0.51 to -0.43 +/- 0.50 (P < 0.05), while peak diastolic SR changed from 0.47 +/- 0.44 to -0.64 +/- 0.84 (P < 0.05). After LIMA grafting, peak systolic SR changed from 0.42 +/- 0.63 to -0.61 +/- 0.40 (P < 0.05), as against peak diastolic SR which changed from -0.80 +/- 1.08 to 0.21 +/- 0.44 (P < 0.05) in the apical septum. Peak systolic SR changed from -0.43 +/- 0.50 to -0.75 +/- 0.46 (P < 0.05), whereas peak diastolic SR changed from -0.64 +/- 0.84 to 0.64 +/- 0.88 (P < 0.05) in the middle septum. CONCLUSIONS: Postsystolic shortening is a marker for both ischemia and successful myocardial reperfusion. By strain rate imaging, we could detect ischemia with a more sensitive and specific method. For anesthesiologists and surgeons, it can be an intraoperative tool for assessing ventricular function after reperfusion.

Aged↗

PubMed2005

Use of the Arndt wire-guided endobronchial blocker to facilitate one-lung ventilation for pediatric empyema during video-assisted thoracoscopy.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has emerged as an innovative and popular procedure for the management of postpneumonic empyema in children refractory to a medical response. One-lung ventilation is required during VATS. In this study, we evaluated the efficacy of intraoperative wire-guided endobronchial blockade (WEB) for achieving 1-lung ventilation during a thoracoscopic procedure for pediatric empyema. METHODS: Eighteen patients undergoing a VATS approach for evacuation of an empyema cavity were studied. We used a new device, a bronchial blocker tube, to establish 1-lung ventilation. Intraoperative oxygenation, ventilation, and hemodynamics, as well as the duration of the operation during 1-lung ventilation were recorded. The number of unsuccessful placement attempts, number of malpositionings of the device, and the number of secondary dislodgements of the device after turning the patient into the lateral position were also counted. The quality of lung deflation and inflation was rated by the surgeon under direct visualization as either excellent, fair, or poor. RESULTS: The mean operative time was 80+/-10.8 (range, 50 approximately 120) min. The mean peak inspiratory pressure under 1-lung ventilation was 28.7+/-3.6 cm H2O, and no desaturation was noted. A number of unsuccessful placement attempts were required in 1 patient (1/18) for left-sided VATS. No malpositioning or secondary dislodgement of the device was noted. The quality of lung deflation was judged as being excellent in all patients. CONCLUSIONS: VATS can safely and effectively be performed in children with a proper anesthetic technique. With the development and clinical use of this new device, the bronchial blocker tube proved to be effective and easy to use for establishing 1-lung ventilation in a pediatric population.

Adolescent↗

PubMed2005

Usefulness of transesophageal echocardiography for transcatheter closure of ostium secundum atrial septum defect with the amplatzer septal occluder.

BACKGROUND: Transcatheter closure of ostium secundum atrial septum defect (ASDII) using the new self-centering occluder, Amplatzer Septal Occluder (ASO), has been well developed in recent years. We describe the importance and role of transesophageal echocardiography (TEE) in the selection and closure of such defects. METHODS: Thirty patients referred for transcatheter closure of ASDII by ASO were enrolled in this study. During catheterization, two-dimensional TEE was performed on all patients during and after transcatheter closure. ASD size and morphology were assessed by TEE before catheterization. The ASD stretched diameter was also measured by TEE and fluoroscopy. RESULTS: With the aid of TEE, transcatheter closure of an ASD was successfully, safely and effectively performed on 29 patients. The mean ASD diameter determined by TEE was 17.4 +/- 4.8 mm. The mean stretched diameters measured by TEE and fluoroscopy were 18.7 +/- 5.6 mm and 17.9 +/- 5.5 mm, respectively. The mean device diameter was 19 +/- 5.6 mm. Immediate complete closure was documented by color Doppler TEE in 29 patients. Complications were encountered in one patient, with the device becoming dislodged into the main pulmonary artery. The device was retrieved by surgery and the defect was repaired in the operating room. CONCLUSIONS: Transcatheter closure of ASDs using an Amplatzer device is feasible, safe and effective. Two-dimensional TEE can provide useful information before, during and after transcatheter closure of ASDs.

Adolescent↗

PubMed2004

Usefulness of intraoperative transesophageal echocardiography in the assessment of surgical repair of pediatric ventricular septal defects with video-assisted endoscopic techniques in children.

BACKGROUND: Mini cardiac operative procedures with video-assisted endoscopic techniques for closure of ventricular septal defects (VSDs) in pediatric patients have become quite popular for cardiac surgery. A precise diagnosis is very important for determining the surgical approach, and evaluation by intraoperative transesophageal echocardiography (TEE) plays a major role in confirmation of the preoperative diagnosis, residual defects, and the need to return to the bypass after repair. METHODS: Sixty-five patients (30 boys and 35 girls; aged 8.7 +/- 5.3 years) who were undergoing minimally invasive closure of VSDs were monitored with a Hewlett-Packard color Doppler pediatric TEE throughout the procedure. RESULTS: Closure of the defect was successfully performed in all patients. Sixty-two patients showed neither residual shunt nor aortic regurgitation after the repair. Residual leaks were detected intraoperatively in 3 patients after the repair. One patient required a return to the bypass with an immediate reoperation due to a residual color jet diameter of > 3 mm. One patient was changed from video-assisted endoscopic techniques to a surgical approach for closure of the VSD from a conventional median sternotomy after identification by TEE of an outlet-type perimembranous VSD with 2 additional muscular VSDs. CONCLUSIONS: Our study showed that, with refinement of surgical closure of VSD via video-assisted endoscopic techniques, intraoperative TEE provides valuable and accurate information for decision-making in surgical management, provides immediate assessment of surgical repairs, and prevents reintervention and the morbidity associated with residual flow.

Adolescent↗

PubMed2003

Delayed hypoxemia after bone cement insertion during total hip replacement under spinal anesthesia--a case report.

We report a case of delayed hypoxemia in an aged healthy male patient, which developed 2 hours after cementation of the prosthesis in total hip replacement (THR) under spinal anesthesia. The patient was doing well throughout the operation but unfortunately, progressive tachypnea was noted 1 h after he was transferred to the recovery room (i.e. 2 h after the application of bone cement into the femur). An hour further, distinct wheeze was heard bilaterally on auscultation, which signified bronchospasm. Arterial blood gases analysis revealed a low PaO2 of 71 mmHg and a decrease of oxygen saturation to 91% with supplement of fractional oxygen of 35%. Aerosolization of bronchodilator with terbutaline was administered and supplemental fractional oxygen was increased to 50%. Although wheezing soon subsided, tachypnea and desaturation persisted. He was then transferred to the surgical intensive care unit for further management. Ventilation-perfusion lung scan was performed, which was suggestive of multiple pulmonary embolism.

Aged↗

PubMed2002

Successful one-lung ventilation in a patient with aberrant tracheal bronchus.

IMPLICATIONS: We report a 47-yr-old patient who underwent surgery for esophageal cancer. Because of the isolated ventilation of the right upper lobe after occlusion of the right mainstem bronchus, bronchoscopic re-confirmation exposed an aberrant tracheal bronchus. A Fogarty tube was introduced to block the tracheal bronchus and provide one-lung ventilation.

Bronchi↗

PubMed2002

Stroke after intraaortic balloon counterpulsation associated with mobile atheroma in thoracic aorta diagnosed using transesophageal echocardiography.

We describe a patient who developed embolic stroke after coronary artery bypass grafting (CABG) associated with intraaortic balloon pump (IABP) insertion. Intraoperative transesophageal echocardiography (TEE) revealed marked irregular mass and disruption of the intimal surface of the thoracic aorta with overlying shaggy echogenic material on the intimal surface of the descending thoracic aortic lumen. This case of stroke after IABP insertion suggested that the balloon inflation fragmented some mobile components on the inner surface of the aorta, and this floating debris entered the systemic circulation. TEE might be able to predict the risk of stroke in such a patient.

Aged↗