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So RTY, Chu DKW, Hui KPY, Mok CKP, Sanyal S, Nicholls JM, Ho JCW, Cheung MC, Ng KC, Yeung HW, Chan MCW, Poon LLM, Zhao J, Peiris M. Mutation nsp6 L232F associated with MERS-CoV zoonotic transmission confers higher viral replication in human respiratory tract cultures ex-vivo. bioRxiv 2023:2023.03.27.534490. [PMID: 37034576 PMCID: PMC10081289 DOI: 10.1101/2023.03.27.534490] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) causes zoonotic disease. Dromedary camels are the source of zoonotic infection. We identified a mutation of amino acid leucine to phenylalanine in the codon 232 position of the non-structural protein 6 (nsp6) (nsp6 L232F) that is repeatedly associated with zoonotic transmission. We generated a pair of isogenic recombinant MERS-CoV with nsp6 232L and 232F residues, respectively, and showed that the nsp6 L232F mutation confers higher replication competence in ex-vivo culture of human nasal and bronchial tissues and in lungs of mice experimentally infected in-vivo. Mechanistically, the nsp6 L232F mutation appeared to modulate autophagy and was associated with higher exocytic virus egress, while innate immune responses and zippering activity of the endoplasmic reticulum remained unaffected. Our study suggests that MERS-CoV nsp6 may contribute to viral adaptation to humans. This highlights the importance of continued surveillance of MERS-CoV in both camels and humans.
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Affiliation(s)
- Ray TY So
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China
| | - Daniel KW Chu
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
- UK Health Security Agency, London, United Kingdom
| | - Kenrie PY Hui
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Chris KP Mok
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Sumana Sanyal
- Sir William Dunn School of Pathology, University of Oxford, UK
| | - John M Nicholls
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - John C. W. Ho
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Man-chun Cheung
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Ka-chun Ng
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Hin-Wo Yeung
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Michael CW Chan
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
| | - Leo LM Poon
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China
| | - Jincun Zhao
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China
| | - Malik Peiris
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People’s Republic of China
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China
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Luo Y, Lv H, Zhao S, Sun Y, Liu C, Chen C, Liang W, Kwok KO, Teo QW, So RTY, Lin Y, Deng Y, Li B, Dai Z, Zhu J, Zhang D, Fernando J, Wu NC, Tun HM, Bruzzone R, Mok CKP, Mu X. Age-related seroprevalence trajectories of seasonal coronaviruses in children including neonates in Guangzhou, China. Int J Infect Dis 2023; 127:26-32. [PMID: 36481488 PMCID: PMC9721286 DOI: 10.1016/j.ijid.2022.11.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES Four seasonal coronaviruses, including human coronavirus (HCoV)-229E and HCoV-OC43, HCoV-NL63, and HCoV-HKU1 cause approximately 15-30% of common colds in adults. However, the full landscape of the immune trajectory to these viruses that covers the whole childhood period is still not well understood. METHODS We evaluated the serological responses against the four seasonal coronaviruses in 1886 children aged under 18 years by using enzyme-linked immunosorbent assay. The optical density values against each HCoV were determined from each sample. Generalized additive models were constructed to determine the relationship between age and seroprevalence throughout the whole childhood period. The specific antibody levels against the four seasonal coronaviruses were also tested from the plasma samples of 485 pairs of postpartum women and their newborn babies. RESULTS The immunoglobulin (Ig) G levels of the four seasonal coronaviruses in the mother and the newborn babies were highly correlated (229E: r = 0.63; OC43: r = 0.65; NL63: r = 0.69; HKU1: r = 0.63). The seroprevalences in children showed a similar trajectory in that the levels of IgG in the neonates dropped significantly and reached the lowest level after the age of around 1 year (229E: 1.18 years; OC43: 0.97 years; NL63: 1.01 years; HKU1: 1.02 years) and then resurgence in the children who aged older than 1 year. Using the lowest level from the generalized additive models as our cutoff, the seroprevalences for HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1 were 98.11%, 96.23%, 96.23% and 94.34% at the age of 16-18 years. CONCLUSION Mothers share HCoV-specific IgGs with their newborn babies and the level of maternal IgGs waned at around 1 year after birth. The resurgence of the HCoV-specific IgGs was found thereafter with the increase in age suggesting repeated infection occurred in children.
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Affiliation(s)
- Yasha Luo
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Huibin Lv
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Shilin Zhao
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Yuanxin Sun
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China,The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chengyi Liu
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Chunke Chen
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, PR China,Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Weiwen Liang
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kin-on Kwok
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Qi Wen Teo
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, USA
| | - Ray TY So
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yihan Lin
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yuhong Deng
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Biyun Li
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Zixi Dai
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jie Zhu
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Dengwei Zhang
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Julia Fernando
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Nicholas C Wu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, USA,Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, USA,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, USA,Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, USA
| | - Hein M. Tun
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China,Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China,The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Roberto Bruzzone
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chris KP Mok
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China,The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China,Corresponding authors:
| | - Xiaoping Mu
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China,Corresponding authors:
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Abstract
A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.
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Affiliation(s)
- Y-H Cho
- Department of Biotechnology, Yonsei University, Seoul, 120-749, South Korea
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Abstract
A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.
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Affiliation(s)
- Y-H Cho
- Department of Biotechnology, Yonsei University, Seoul, 120-749, South Korea
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Tsang HWH, Mok CK, Au Yeung YT, Chan SYC. The effect of Qigong on general and psychosocial health of elderly with chronic physical illnesses: a randomized clinical trial. Int J Geriatr Psychiatry 2003; 18:441-9. [PMID: 12766922 DOI: 10.1002/gps.861] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Based on the model by Tsang et al. (2002) which summarized the etiological factors and consequences of depression in elderly with chronic physical illnesses, a randomized clinical trial of a special form of Qigong (The Eight Section Brocades) was conducted to assess if it improved the biopsychosocial health of participants. DESIGN 50 geriatric patients in sub-acute stage of chronic physical illnesses were recruited and randomly assigned into the intervention and control group. The intervention group was given a 12-week period of Qigong practice while the control group was given traditional remedial rehabilitation activities. RESULTS The intervention group participants expressed improvement in physical health, ADL, psychological health, social relationship, and health in general as reflected by scores of the Perceived Benefit Questionnaire and informal feedback. CONCLUSION Although results are not significant in the generalization measures, it may be due to small effect size, small sample size, and short intervention period. Although not all of the hypotheses are supported, this report shows that Qigong (the Eight Section Brocades) is promising as an alternative intervention for elderly with chronic physical illness to improve their biopsychosocial health. More systematic evaluation with larger sample size and longer period of intervention is now underway in Hong Kong. Results will be reported once available.
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Affiliation(s)
- Hector W H Tsang
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong. /rshtsang
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Chan JHM, Tsui EYK, Chan CY, Lai KF, Chau LF, Fong D, Mok CK, Cheung YK, Wong KPC, Yuen MK. Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage. Eur Radiol 2002; 12:2317-21. [PMID: 12195488 DOI: 10.1007/s00330-001-1285-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2001] [Revised: 11/15/2001] [Accepted: 11/22/2001] [Indexed: 12/01/2022]
Abstract
The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images ( p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain.
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Affiliation(s)
- J H M Chan
- Department of Diagnostic Radiology, Tuen Mun Hospital, Tsing Chung Koon Road, Tuen Mun, Hong Kong.
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Mak WL, Mok CK. Pseudohyperkalemia in thrombocythemia. Chin Med J (Engl) 2001; 114:1216-7. [PMID: 11729525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Affiliation(s)
- W L Mak
- Department of Clinical Pathology, Tuen Mun Hospital, Tuen Mun, Hong Kong Special Administrative Region, China.
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Abstract
A 23-year-old female university student was presented with recent onset of non-specific headache and dizziness. She had no neurological deficit on neurological examination and magnetic resonance imaging of the brain revealed diffuse enhancement in the basal cisterns and cerebral sulci. She was treated as tuberculous meningitis but she did not improve and developed respiratory arrest. Autopsy showed primary multifocal leptomeningeal gliomatosis.
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Affiliation(s)
- E Y Tsui
- Department of Radiology, Tuen Mun Hospital, Hong Kong, NT, PR China
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9
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Tsui EY, Cheung YK, Mok CK, Yuen MK, Chan JH. Hypertrophic olivary degeneration following surgical excision of brainstem cavernous hemangioma: a case report. Clin Imaging 1999; 23:215-7. [PMID: 10631896 DOI: 10.1016/s0899-7071(99)00147-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubo-olivary pathway. It is distinguished from other types of neuronal degeneration in that hypertrophy, rather than atrophy, takes place in the neurons in the inferior olivary nucleus. Prior to the invention of Magnetic Resonance Imaging (MRI), HOD was difficult to be detected, and a firm diagnosis could only be made at autopsy. We present a case of bilateral HOD following surgical excision of a cavernous hemangioma in the brainstem. The literature and imaging findings of this uncommon condition are reviewed.
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Affiliation(s)
- E Y Tsui
- Department of Radiology, Tuen Mun Hospital, Hong Kong
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Abstract
BACKGROUND Ruptured sinus of Valsalva aneurysm is a rare cardiac anomaly and long-term survival after surgical treatment is not well established. This study was designed to investigate the determinants of long-term survival after repair of ruptured sinus of Valsalva aneurysm. METHODS From April 1978 to April 1996, 53 patients underwent operation for ruptured sinus of Valsalva aneurysm. The incidence among our cardiac surgical population was 0.56%. Long-term survival was investigated in 46 patients (13 to 65 years) who survived the operation, with 96.2% follow-up completeness (mean+/-standard deviation, 6.5+/-4.9 years; maximum, 17.2 years), by univariate and multivariate analyses. RESULTS There was no early operative death and no recurrence after the initial repair. Actuarial survival was 83.8%+/-8.4% at 15 years. Reoperation, aneurysm draining into the left ventricle, aortic prosthetic dehiscence, bacterial endocarditis, and aortic cross-clamp time (<70 minutes) were significant factors in long-term survival (p < 0.05). Multivariate analysis revealed that only aortic prosthesis dehiscence was the significant factor influencing late survival (p = 0.0001). CONCLUSIONS Surgical treatment for ruptured sinus of Valsalva aneurysm is safe and has satisfactory results. Aortic prosthesis dehiscence is the independent determinant for long-term survival. Other factors including bacterial endocarditis, concomitant ventricular septal defect repair, and aortic valve replacement did not independently influence long-term survival.
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Affiliation(s)
- W K Au
- Department of Surgery, University of Hong Kong, Grantham Hospital, Aberdeen
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Suen WS, Mok CK, Chiu SW, Cheung KL, Lee WT, Cheung D, Das SR, He GW. Risk factors for development of acute renal failure (ARF) requiring dialysis in patients undergoing cardiac surgery. Angiology 1998; 49:789-800. [PMID: 9783643 DOI: 10.1177/000331979804900902] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Acute renal failure (ARF) is one of the major complications after cardiopulmonary bypass for open heart operations. The present study was undertaken to identify the risk factors for the development of ARF following cardiopulmonary bypass (CPB). Four hundred and forty-seven consecutive patients who underwent open heart procedures from July 1994 to June 1995 were analyzed retrospectively. Their mean age was 55.6 +/- 14.2 (SD) years (range, 18 to 80). Dialysis was instituted whenever a patient exhibited inadequate urine output (<0.5 mL/kg/hr) for 2 to 3 hours despite correction of hemodynamic status and diuretic therapy, especially if fluid overload, hyperkalemia, or metabolic acidosis were also present. Twenty variables were analyzed by univariate analysis; these included nine preoperative variables--age, sex, hypertension, atherosclerosis, diabetes mellitus, left ventricular end-diastolic dimension (LVEDD) >5 cm, preoperative congestive heart failure, renal insufficiency (serum creatinine > or =130 micromol/L on two occasions), and sepsis--10 intraoperative variables--duration of CPB, redo procedures, emergency surgery, use of intraaortic balloon pump (IABP) in operating room, use of gentamicin, use of ceftriaxone, use of sulbactam/ampicillin, requirement of deep hypothermic circulatory arrest, duration of low mean perfusion pressure (mean pressure <50 mmHg for more than 30 minutes), operation on multiple valves--and one postoperative variable--significant hypotension (systolic blood pressure less than 90 mmHg for more than 1 hour). Significant variables or the variables having a trend (p<0.1) to be associated with ARF were included in stepwise multiple logistic regression analyses. Three regression analyses were performed separately. The incidence of ARF requiring dialysis in the study period was 15.0%. Significant risk factors for whole group of patients (regression I) were preoperative renal insufficiency (p<0.0001), postoperative hypotension (p<0.0001), cardiopulmonary bypass time more than 140 min (p<0.005), preoperative congestive heart failure (p<0.01), and history of diabetes mellitus (p<0.01). The risk factors in the valve group of patients (regression II) were preoperative renal insufficiency (p<0.0001) and postoperative hypotension (p<0.05). Risk factors in the CABG patients (regression III) were postoperative hypotension (p=0.0001), CPB time more than 140 min (p<0.05), preoperative renal insufficiency (p<0.05), and age (p<0.05). The authors conclude that preoperative renal insufficiency and postoperative hypotension are the most important independent risk factors for ARF in postcardiac surgical patients. In addition, CPB time greater than 140 minutes and old age are also independent risk factors for ARF in CABG patients. CPB time more than 140 minutes, history of diabetes mellitus, and preoperative congestive heart failure are independent risk factors for development of ARF in our total group of patients. These findings may have important clinical implications in the prevention of ARF in postcardiac surgical patients.
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Affiliation(s)
- W S Suen
- Department of Surgery, University of Hong Kong, China
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12
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Mok CK, Lau ST, Leung PM, Wong SY, Siu W, Au SY. A survey of the long term outcome of elderly stroke survivors and the needs of their carers. Hong Kong Med J 1997; 3:158-162. [PMID: 11850566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
A survey was conducted to assess the long term outcome of 60 elderly stroke survivors (mean age, 81.7 years). Of these patients, 48% died within one year of discharge and 79% of the mortality occurred in the first six months. Patients discharged to institutions after the initial stroke had a significantly higher risk of death in one year (relative risk=1.47) compared with those who were discharged home. For those who survived for a mean period of 18.6months, 72% (21/29) were institutionalised. This group had significantly worse functional status and mobility compared with those who were living at home. The caring of elderly stroke patients was considered a heavy burden for most carers at home or in institutions and the need for medical and social support was great.
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Affiliation(s)
- C K Mok
- Department of Geriatrics, Tuen Mun Hospital, Tuen Mun, Hong Kong
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Abstract
BACKGROUND It is desirable to repair but not replace the aortic valve in patients with ventricular septal defect and acquired aortic regurgitation. Precise definition of the valvar pathology with monitoring of its repair perioperatively would enhance the surgical management of this condition. METHODS Fourteen consecutive patients (age, 10.6 +/- 6 years; weight 29.7 +/- 5.7 kg) who underwent repair of ventricular septal defect with aortic regurgitation were studied by intraoperative transesophageal echocardiography. The severity of prolapse of each of the individual aortic cusps and its adjacent sinus was assessed and the valvar regurgitation quantified by Doppler-derived regurgitant indices. The echocardiographic and surgical findings were correlated and the preoperative and postoperative echocardiographic data were compared to assess the effectiveness of operation. RESULTS Eight subarterial and six perimembranous defects were located accurately and their sizes (11.8 +/- 3.0 mm) correlated well (r = 0.80) with the surgical measurements. Transesophageal echocardiography detected prolapse of the aortic valve and its sinus in all 14 patients. The severity of the prolapse was severe in 10, moderate in 4, and mild in 5 leaflets. One the basis of these findings, together with the Doppler-derived mean regurgitant indices, exploration of the valve and valvuloplasty were executed appropriately in 12 of 14 patients. In all 14 patients, transesophageal echocardiography after bypass revealed no further cuspal prolapse and significant reduction of the mean regurgitant index (0.55 +/- 0.23 to 0.17 +/- 0.15, p < 0.0001). Residual ventricular septal defect was detected in 5 patients and the only patient with significant shunting who required reexploration was identified correctly. CONCLUSIONS Intraoperative transesophageal echocardiography can assess effectively the surgical repair of ventricular septal defect with aortic regurgitation and provide information that directs and alters surgical plans to the benefit of patients.
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Affiliation(s)
- M P Leung
- Department of Paediatrics, Grantham Hospital, University of Hong Kong, Aberdeen, Hong Kong
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Abstract
BACKGROUND Nasopharyngeal carcinoma (NPC), unlike other head and neck cancers,is known for its propensity for distant metastases. Chemotherapy remains the mainstay of treatment because of this and the chemosensitivity of the tumour, but long-term control is rare. The surgical management of pulmonary metastases of other extrathoracic malignancies prompted this review of surgical management of patients with NPC. METHODS Thirteen thoracotomies were performed in 12 patients with pulmonary metastases as the first and only site of relapse of nasopharyngeal carcinoma. Postoperative chemotherapy was given in four patients, radiotherapy to the mediastinum in one patient and both chemotherapy and radiotherapy in two patients. The survival pattern of this group of 12 patients was compared with a historical control group consisting of 65 patients without surgical resection. RESULTS Lymph node involvement was documented in four patients during operation. Four patients relapsed after surgical resection, two of them were from the group of three patients with lymph node involvement. The site of subsequent relapse was the lung for three patients and the skeletal system for the fourth. The 2 year actuarial survival of the surgically resected group compared favourably with the historical control group (80% and 24.1%, respectively; P=0.0002 by Mantel-Cox text). CONCLUSIONS Surgical resection of pulmonary metastases from NPC seems to be a promising approach thought the effect of case selection cannot be excluded and further studies are indicated. The importance of exploration and dissection of mediastinal nodes in the surgical management of pulmonary metastases from NPC was demonstrated.
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Affiliation(s)
- L C Cheng
- Division of Cardiothoracic Surgery, Department of Surgery, University of Hong Kong
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15
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Wu JL, Leung MP, Karlberg J, Chiu C, Lee J, Mok CK. Surgical repair of coarctation of the aorta in neonates: factors affecting early mortality and re-coarctation. Cardiovasc Surg 1995; 3:573-8. [PMID: 8745172 DOI: 10.1016/0967-2109(96)82849-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Between October 1979 and January 1993, 85 Chinese neonates in Hong Kong underwent surgical repair for coarctation of the aorta. Their mean (s.e.) age and body weight at operation was 15.6(8.5) days and 3.06(0.56) kg, respectively. Simple coarctation was present in 17 babies, while 36 had additional ventricular septal defect and 31 had associated major complex intracardiac lesions. Subclavian flap aortoplasty was performed in 56 babies, resection with end-to-end anastomosis in 18 and aortoplasty with the use of a GORETEX patch in 11. The overall early mortality rate was 16.5%. To identify risk factors for early operative mortality, various clinical variables, surgical options, associated heart lesions and dimensions of the aortic arch at different sites for each patient were reviewed. Univariate analysis identified statistically significant differences between the survivors and non-survivors for the following factors: preoperative body-weight, arterial pH and base excess, serum urea and creatinine levels. Stepwise logistic regression further distinguished serum creatinine levels and the period of operation as two significant risk factors. Contrary to previous reports, the dimensions of the aortic arch and type of surgery did not affect early operative mortality. Among the 71 hospital survivors followed for 38.2(38) months, residual or recurrent coarctation of the aorta was detected in 12(17%). The different surgical operations were not related to the incidence of late complication. The size of the distal transverse arch, however, was different (P=0.05) in those who did and did not develop aortic sequela. Successful balloon angioplasty was subsequently performed in 11 patients. In an era of echocardiography with prenatal diagnosis and therapeutic catheterization, early recognition of the disease with prompt prostaglandin infusion should prevent collapse of the baby, thus avoiding renal impairment and sever metabolic acidosis. Balloon angioplasty would offer a simple effective treatment of patients who developed aortic re-coarctation.
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Affiliation(s)
- J L Wu
- Department of Paediatrics and Surgery, The Grantham Hospital and Queen Mary Hospital, University of Hong Kong, China
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16
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Abstract
The article describes two Chinese boys ages 2 and 3 years with unilateral Wilms' tumors complicated by intracaval and intracardiac extension. In contrast to the previously recommended treatment with surgery followed by chemotherapy and radiation therapy, the children were managed primarily with combination chemotherapy before definitive operation. Reduction of tumor size on serial imaging was documented, and no viable tumor cells were found when the involved kidney and right atrium were explored. Both patients remained alive without evidence of disease more than 5 years after initial diagnosis. A literature search revealed case reports and retrospective analyses of 70 patients with Wilms' tumors and intracardiac involvement, and a tendency toward preoperative chemotherapy with or without the addition of radiation therapy was observed. The overall outcome of this group of patients parallels the outcome of those without intracardiac extension by histology and stage. Wilms' tumor presenting with extension into the inferior vena cava and right atrium is thus rare and renders the affected child with additional cardiovascular complications and operative risks. As a result of the uncommon occurrence, a consensus on management based on prospective study would be difficult. The present report and the literature are supportive of the use of preoperative chemotherapy in the initial management of advanced Wilms' tumor extending into the right atrium.
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Affiliation(s)
- A C Lee
- Department of Paediatrics, University of Hong Kong, Queen Mary Hospital, Pokfulam
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17
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Abstract
To examine the impact on survival and clinical course of incorporating the morphologic classification of the right ventricle into the evolving management strategy for babies with pulmonary atresia and intact ventricular septum, the surgical results and follow-up status of the first 62 consecutive patients managed in this hospital between 1979 and 1990 were reviewed. Before 1984, all 23 babies from group I underwent primary right ventricular outflow reconstruction irrespective of right ventricular morphology and size. Since 1984, depending on the morphology and size of the right ventricle, 39 babies from group II had either closed transventricular pulmonary valvotomy (n = 31) or a shunt operation (n = 8). There were 10 hospital (43%) and 2 late deaths (total mortality 52%) in our group I patients. Three of the 11 long-term survivors had cyanosis at rest but none had any residual pressure gradient across the pulmonary outflow. Group II had 6 hospital (15%) and 4 late deaths (total mortality = 26%). Of the 29 long-term survivors, 9 had a second-stage right ventricular outflow reconstruction, 8 had balloon valvuloplasty and 2 had successful Fontan operation. At the latest follow-up, 5 children from this group have cyanosis at rest, 1 has a residual gradient (55 mm Hg) across the infundibulum, and 3 have right ventricular dysfunction. The hospital and total mortality for babies in group II was significantly lower than that in group I (p < 0.01). These data suggest that tailoring the treatment to the right ventricular anatomy results in a lower overall mortality although long term postoperative hemodynamic abnormalities are observed in both groups.
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Affiliation(s)
- M P Leung
- Department of Paediatrics, Grantham Hospital, University of Hong Kong, Aberdeen
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18
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Abstract
Invasive cystic thymoma is reported in two siblings (an 11-year-old girl and a 9-year-old boy) and the radiographic, CT and ultrasonographic features are described. The tumours were removed by thoracotomy. Familial thymic masses are reviewed, and the imaging differential diagnosis of cystic anterior mediastinal mass in a child is discussed.
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Affiliation(s)
- W W Lam
- Department of Diagnostic Radiology, Queen Mary Hospital, Hong Kong
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19
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Abstract
Two children, aged 7 and 6 years, had severe Ebstein's malformation of the tricuspid valve and underwent operation because of progressive cyanosis (saturation, 70%). Preoperative angiography demonstrated linear attachment of the distal edges of the displaced anterosuperior and mural leaflets, leaving only a "keyhole" communication between the atrialized and functional portions of the right ventricle. Operation was directed toward completely excising these dysplastic leaflets, which were obstructing the flow of blood. The continuity between the functional right ventricle and pulmonary trunk was left intact. In addition, an atriopulmonary truncal connection was established. Postoperatively, both children were in functional class I with arterial saturation of 95%. Angiography and Doppler echocardiography demonstrated that there was a dominant phase of systolic flow of blood up the pulmonary trunk from the right ventricle, and also diastolic filling of the pulmonary arteries through the atriopulmonary truncal connection. The filling patterns did not change over time for the follow-up period of 4 and 1.5 years, respectively. This modified Fontan procedure appears to be an effective surgical alternative for some patients with severe Ebstein's malformation and predominant tricuspid stenosis.
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Affiliation(s)
- M P Leung
- Department of Paediatrics, Grantham Hospital, University of Hong Kong
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20
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Abstract
During a 2 1/2-year period, staged procedures of transventricular closed pulmonary valvotomy followed by balloon valvuloplasty were attempted in 12 babies with pulmonary atresia and an intact ventricular septum. All babies immediately underwent valvotomy when echocardiography revealed a tripartite right ventricle with adequate inflow and outflow dimensions and without sinusoidal-coronary arterial fistulas. After valvotomy, the overall mortality rate was 25% (3/12), but the only surgical death (1/12, 8%) was due to failure to establish continuity between the right ventricular cavity and the pulmonary trunk. The other 2 babies died of neonatal complications after successful valvotomy. Angiocardiography performed 5 to 18 months after valvotomy documented substantial growth of the right ventricular inflow and outflow dimensions in the 9 survivors. Twelve balloon dilation procedures were then performed in 7 babies. All except 1 achieved a significant drop in the right ventricular to left ventricular peak systolic pressure ratio (0.96 +/- 0.40 to 0.56 +/- 0.28; p less than 0.01). Balloon valvuloplasty was not required in 1 baby and failed in the other, who then underwent successful right ventricular outflow tract reconstruction. After these staged procedures, follow-up at 1 month to 20 months (mean follow-up, 14.8 months) revealed resting cyanosis in 3 babies, which was related to severe residual infundibular stenosis (55 mm Hg) in 1 and a subnormal tricuspid valve annulus in 2. The remaining 5 babies (including 1 who required no valvuloplasty) were active and pink (saturation greater than 97%) and had a mean Doppler estimated gradient of 19 mm Hg (range, 8 to 36 mm Hg) across the pulmonary valve.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M P Leung
- Department of Paediatrics, Grantham Hospital, University of Hong Kong, Aberdeen
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21
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Lau KC, Cheung HH, Mok CK. Congenital absence of the pulmonary valve, intact interventricular septum, and patent ductus arteriosus: management in a newborn infant. Am Heart J 1990; 120:711-4. [PMID: 2202195 DOI: 10.1016/0002-8703(90)90039-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- K C Lau
- Department of Pediatrics, University of Hong Kong
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22
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Abstract
Severe ostial stenosis of the coronary arteries following aortic valve replacement is a potentially lethal complication. The usual presentations are recent onset of severe angina, ventricular arrhythmias, congestive heart failure, and sudden death. It is generally accepted to arise from injury to the coronary arteries during direct cannulation and continuous perfusion of cardioplegia under high pressure during operation. We report on a patient who developed critical left coronary ostial stenosis after aortic valve replacement. The cause for the stenosis was probably related to the over-sizing and orientation of the prosthesis. The prosthesis was replaced and patch angioplasty of the left coronary ostia performed. The patient was well with normal coronary anatomy three years after surgery.
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Affiliation(s)
- H H Cheung
- Department of Surgery, University of Hong Kong, Grantham Hospital
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23
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Teoh SH, Martin RL, Lim SC, Lee KH, Mok CK, Kwok WC. Delrin as an occluder material. ASAIO Trans 1990; 36:M417-21. [PMID: 2252716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Delrin (DR) has been used in biomedical applications for more than 25 years. Because of durability concerns, it was replaced by the expensive Pyrolytic Carbon (PC) in numerous cardiac valves. However, the durability problem could be related to design rather than poor materials selection. Recent reports on brittle fracture of PC, leading to sudden deaths, have prompted a critical comparison between DR and PC in the St. Vincents Mechanical (SVM) heart valves. Three SVM-DR and SVM-PC valves were subjected to accelerated life cycle tests, and examined for wear at 400 million cycles. These results were compared to those of Björk-Shiley Delrin (BS-DR) valves. Wear in BS-DR valves in vivo for more than 17 years were also analyzed and compared. Using a linear (wear depth)-log (cycles) plot, wear rates in mm/log (million cycles) were obtained. The results showed that the wear rates for DR and PC in SVM valves are close. The double reduction in wear rate of the SVM-DR, compared to BS-DR, is probably due to the lower contact stresses of the SVM valves. SVM-DR in vivo should, therefore, have lower wear. The PC discs also showed edge chipping and hairline cracks. The authors conclude that the durability of DR can be improved by design and, since it is more impact resistant than PC, it is a safer, more inexpensive occluder material for cardiac valves.
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Affiliation(s)
- S H Teoh
- Mechanical and Production Engineering Department, National University of Singapore
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24
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Abstract
A 54-year-old man underwent aortic valve replacement for syphilitic aortic regurgitation. Eight years later, he was admitted with sudden precordial discomfort and symptoms of superior vena caval obstruction. Ascending aortic dissection was diagnosed by echocardiography and computed tomography of the thorax. The patient succumbed rapidly after admission. Postmortem findings and histological features were compatible with syphilitic aortitis, without significant atherosclerosis. This case report adds to the sparse literature on aortic dissection complicating syphilitic aortitis, and illustrates that, at certain stages of the disease process, syphilitic aortitis can lead to such a degree of mechanical instability of the aortic wall as to predispose to dissection.
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Affiliation(s)
- Y T Tai
- Department of Medicine, Queen Mary Hospital, Hong Kong
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25
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Chow WH, Tai YT, Mok CK, Cheung KL. Ruptured aneurysm of the sinus of Valsalva. Cathet Cardiovasc Diagn 1990; 19:148. [PMID: 2306779 DOI: 10.1002/ccd.1810190219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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26
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Abstract
Left ventricular pseudoaneurysms, with or without overt ventricular rupture, are usually fatal in the absence of prompt surgical intervention. This report details the long-term survival of a patient who developed a left ventricular pseudoaneurysm following repair of ventricular rupture subsequent to replacement of the mitral valve, with spontaneous closure of the "neck" of the pseudoaneurysm.
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Affiliation(s)
- Y T Tai
- Department of Medicine, Grantham Hospital, University of Hong Kong
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27
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Abstract
Infection of sternotomy wounds due to Mycobacterium fortuitum-chelonei complex postoperatively was noted in ten patients in 1987 and six patients in 1988 in our hospital. The first ten patients were treated with a combination of ofloxacin and amikacin, successfully in nine. In the six later patients, five had M fortuitum infection and one had M chelonei infection. In those five we used single daily-dose ofloxacin, 600 mg, in three with rapid clinical response and bacteriologic cure. The MIC of ofloxacin for these three isolates ranged from 0.32 mg/L to 1.25 mg/L, and peak serum level of ofloxacin assessed by high-performance liquid chromatography ranged from 4.1 mg/L to 8.0 mg/L. Monotherapy with ofloxacin is recommended for M fortuitum infection of wound and soft tissue, with in vitro susceptibility studies as a guide, pending further reinforcing clinical evidence.
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Affiliation(s)
- W W Yew
- Tuberculosis and Chest Unit, Grantham Hospital, Hong Kong
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28
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Abstract
A patient with an asymptomatic aortic right ventricular fistula acquired after aortic valve and mitral valve replacement is presented. This was diagnosed by two-dimensional and pulsed Doppler echocardiography, and confirmed at cardiac catheterization.
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Affiliation(s)
- W H Chow
- Department of Medicine, Grantham Hospital, Hong Kong
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29
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Abstract
A temporary pacing electrode was inserted in a patient with severe calcific aortic stenosis complicated by complete atrioventricular block. Despite normal pacing and sensing function, a diagnosis of myocardial perforation was made on the basis of a lateral chest radiograph. Neither the surface electrocardiogram nor the frontal chest radiograph suggested evidence of myocardial perforation, and echocardiographic diagnosis was limited by poor echogenicity of the patient. Biventricular perforation with pericardial effusion were documented at operation.
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Affiliation(s)
- C P Lau
- Department of Medicine, Queen Mary Hospital, University of Hong Kong
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30
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Abstract
Ten male patients with extensive primary endodermal sinus tumor of the mediastinum were treated with chemotherapy (with or without surgical excision and radiation therapy) between 1977 and 1985. Three patients, treated with cyclophosphamide-vincristine-based chemotherapy, died 1.5, 2.5, and 6.0 months, respectively, after initial diagnosis. Of the seven patients treated with cisplatin-based chemotherapy, one patient died of septicemia at 2.5 months after diagnosis and was disease-free at autopsy examination. Three other patients died of progressive disease at 7.0, 13.0, and 14.0 months, respectively. The three survivors remain alive at 17.0, 31.0, and 40.0 months from diagnosis; all are without evidence of disease. Of the three patients who underwent excision of the residual mediastinal tumor after cisplatin-based chemotherapy, persistent local disease was found in two patients. One of these two patients died of recurrent disease. All surviving patients had surgical resection of the tumor either before or after cisplatin-based chemotherapy, with or without radiotherapy and the timing of therapeutic interventions was guided by changes in the serum alpha-fetoprotein concentrations after initial therapy and during follow-up. Our experience suggests that the optimal management of patients with primary mediastinal endodermal sinus tumor requires an aggressive multidisciplinary approach guided by the extent of the tumor and the serum tumor marker levels.
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Affiliation(s)
- J S Sham
- Department of Radiotherapy and Oncology, Queen Mary Hospital, Hong Kong
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31
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Leung MP, Cheung DL, Lo RN, Mok CK, Lee J, Yeung CY. The management of symptomatic neonates with suspected congenital heart disease using combined cross-sectional echocardiography and pulsed Doppler flow study as the definitive investigations. Int J Cardiol 1989; 24:41-6. [PMID: 2759755 DOI: 10.1016/0167-5273(89)90039-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We studied prospectively 140 consecutive symptomatic neonates with suspected congenital heart disease by combined cross-sectional and pulsed Doppler echocardiography. Using the sequential segmental approach, the anatomy at all cardiovascular junctions was clearly defined in 89 (64%) babies. Based on the non-invasive investigations, 47 went to surgery while 42 babies were treated medically. The other 51 babies underwent further cardiac catheterisation. Of these, only 23 (16%) required diagnostic catheterisation prior to their management decision. The remaining 28 babies were catheterised for (1) angiographic measurement of anatomical structures (n = 12), (2) haemodynamic measurement (n = 1), and (3) balloon atrial septostomy (n = 15). One hundred and two babies had ultimate verification of their echocardiographic diagnoses. A total of 612 cardiovascular segments were identified. There were 33 (5%) echocardiographic errors, 23 of missed or uncertain diagnosis and 10 wrong interpretations. The diagnostic sensitivity and specificity for the combined non-invasive technique were thus 96 and 98%, respectively. Only one death was attributed directly to an echocardiographic error. Hence when the clinical outcome was taken into consideration, 88 of the 89 neonates without an initial catheterisation were judged to be appropriately managed for their presentation.
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Affiliation(s)
- M P Leung
- Department of Paediatrics, Grantham Hospital, University of Hong Kong
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32
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Abstract
Mycobacterium fortuitum infection of soft tissue and wound (postoperative or otherwise) has been well reported in medical literature. In 1987, ten patients in our hospital with various cardiac diagnoses requiring open-heart surgery developed M fortuitum infection at the sternotomy site. As successful chemotherapy, in addition to surgical debridement, relies on in vitro susceptibility testing, ofloxacin and amikacin were thus assessed and found to have very satisfactory MIC. For the former: 1.25 mg/L for eight isolates, 2.5 mg/L for one isolate, and greater than 20 mg/L for one isolate were found. For the latter: 1 mg/L for six isolates, 2 mg/L for two isolates, and 4 mg/L and 8 mg/L for the remaining two isolates were found, respectively. These patients were given ofloxacin (300 mg once daily to 1,200 mg daily in divided doses) for three to six months and 500 mg amikacin daily (in two divided doses intravenously or intramuscularly) for three to eight weeks. The clinical outcome was favorable except for one patient who died of bacteremia due to M fortuitum coupled with many medical complications. Encouraged by these preliminary results, a future prospective study with ofloxacin as single agent for soft tissue, particularly postoperative sepsis due to M fortuitum, will be planned.
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Affiliation(s)
- W W Yew
- Tuberculosis and Chest Unit, Grantham Hospital, Wong Chuk Hang, Aberdeen, Hong Kong
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33
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Abstract
A left subclavian arterioesophageal fistula was diagnosed in a 35-year-old man at exploratory thoracotomy for suspected aortoesophageal fistula. After successful closure of the arterial fistula the patient developed a mediastinal abscess and esophagopleural fistula. The latter was successfully managed by retrosternal jejunal esophagoplasty followed by excision of the thoracic esophagus. This report documents a case of left subclavian arterioesophageal fistula and illustrates the importance of early diagnosis and surgical intervention of arterial perforation secondary to a foreign body in the esophagus.
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Affiliation(s)
- C K Mok
- Department of Surgery, University of Hong Kong, Grantham Hospital
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34
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Abstract
In this prospective study, 27 consecutive neonates suspected to be suffering from pulmonary atresia and intact ventricular septum underwent detailed two-dimensional echocardiographic examination before cardiac catheterization. Of the 27 neonates 25 had pulmonary atresia and intact ventricular septum and the remaining 2 had "functional pulmonary atresia" secondary to severe Ebstein's anomaly of the tricuspid valve. In all 25 neonates with pulmonary atresia and intact ventricular septum, the diagnosis and right ventricular morphology based on the tripartite approach were correctly established by echocardiography. The associated Ebstein's anomaly in two babies with pulmonary atresia and intact ventricular septum was also correctly identified by echocardiography. Among the five babies who had a sinusoidal-coronary artery communication, echocardiography demonstrated the fistula in one and provided clues for its diagnosis in two others. In the 25 neonates with pulmonary atresia and intact ventricular septum, the echocardiographic dimensions of their tricuspid anulus, right ventricular infundibulum and main pulmonary artery correlated well with the angiocardiographic measurements (r greater than 0.8). The results of this study suggest that, in the management of neonates with pulmonary atresia and intact ventricular septum, preoperative evaluation by echocardiography is usually sufficient and cardiac catheterization should be reserved for selected cases.
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Affiliation(s)
- M P Leung
- Department of Paediatrics, University of Hong Kong, Grantham Hospital
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35
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Abstract
A 78 year old man underwent aortic valve replacement because of acute aortic regurgitation and intractable heart failure. At operation the intact commissure between the left and right coronary cusps of a grossly normal aortic valve was found to have separated from the aortic wall. Histopathological examination of the surgical specimen showed that the site of separation was an atheromatous plaque. This is believed to be the first report of this feature.
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Affiliation(s)
- C K Mok
- Department of Surgery, University of Hong Kong, Grantham Hospital
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36
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Mok CK, Cheung DL, Chiu CS, Aung-Khin M. An unusual lethal complication of preservation of chordae tendineae in mitral valve replacement. J Thorac Cardiovasc Surg 1988; 95:534-6. [PMID: 3343862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In two patients, several chordae tendineae of the mural leaflet were preserved during mitral valve replacement. Hemorrhagic necrosis and spontaneous rupture of the preserved posterior papillary muscle led to disc entrapment and the death of both patients.
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Affiliation(s)
- C K Mok
- Department of Surgery, University of Hong Kong
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37
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Leung MP, Mok CK, Cheung DL, Lau KC. Echocardiographic diagnosis of anastomotic stricture following surgical correction of supracardiac total anomalous pulmonary venous connection. Am Heart J 1987; 114:1518-20. [PMID: 3687705 DOI: 10.1016/0002-8703(87)90559-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- M P Leung
- Department of Paediatrics, University of Hong Kong, Grantham Hospital
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38
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Lo RN, Mok CK, Leung MP, Lau KC, Cheung DL. Cross-sectional and pulsed Doppler echocardiographic features of anomalous origin of right pulmonary artery from the ascending aorta. Am J Cardiol 1987; 60:921-4. [PMID: 3661413 DOI: 10.1016/0002-9149(87)91053-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- R N Lo
- Department of Paediatrics, University of Hong Kong, Grantham Hospital
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39
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Lee J, Cheung KL, Wang R, Mok CK, Khin MA. Malignant fibrous histiocytoma of left atrium. J Thorac Cardiovasc Surg 1987; 94:450-2. [PMID: 3041125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A case is presented of malignant fibrous histiocytoma arising adjacent to a mitral Carpentier-Edwards bioprosthesis placed 6 years previously.
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40
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Leung MP, Mok CK, Hui PW, Lo RN, Lau KC, Li CK, Cheung DL. Cross-sectional and pulsed Doppler echocardiography of the atrioventricular junction of hearts with univentricular atrioventricular connexion. Int J Cardiol 1987; 15:215-30. [PMID: 3583459 DOI: 10.1016/0167-5273(87)90317-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The atrioventricular junction of 52 consecutive patients with univentricular atrioventricular connexion was examined by cross-sectional and pulsed Doppler echocardiography. The echocardiographic features were then compared with catheterisation and cineangiographic findings. In the diagnosis of the mode of atrioventricular connexion, cross-sectional echocardiography was superior to cineangiography in differentiating single inlet with absence of one atrioventricular connexion from double inlet with a common atrioventricular valve. Straddling atrioventricular valves were diagnosed by echocardiography alone. Using pulsed Doppler echocardiography, the diagnostic sensitivity of atrioventricular valvar regurgitation was 92.6% and the specificity 100%. By mapping the regurgitant jet with pulsed Doppler echocardiography, an index was derived to evaluate the severity of atrioventricular valvar regurgitation. The indices obtained correlated well with cineangiographic grading on a three-point scale (Spearman rank correlation coefficient: rs = 0.9). Thus, cross-sectional echocardiography coupled with a range-gated Doppler system provide accurate anatomical details of the atrioventricular junction and reliable assessment of atrioventricular valvar regurgitation in patients with univentricular atrioventricular connexion.
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41
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Abstract
Balloon atrial septostomy was performed under two-dimensional echocardiographic control in 18 consecutive neonates. Initially, a subcostal long-axis view was used to guide the catheter into the right atrium. Then, by tilting the transducer medially, a plane traversing the inferior vena caval-right atrial junction, foramen ovale, and left atrium was obtained to direct the manipulation of the catheter into the left atrium and monitor the septostomy procedure. As the catheter was always in view, catheter manipulation was easy and complications were avoided.
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42
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Lam WK, So SY, Ngan H, Aung-Khin M, Mok CK. A young woman with apparent increase in the transverse cardiac diameter. Chest 1986; 90:595-6. [PMID: 2944715 DOI: 10.1378/chest.90.4.595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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43
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Abstract
A 46-year-old lady with leiomyosarcoma of the inferior vena cava extending into the hepatic veins and right atrium is described. The diagnosis was made preoperatively by a combination of radiological techniques including computed tomography, inferior vena cavography, arteriography, and two-dimensional echocardiography. The clinical presentation, radiological features and management of this condition are reviewed.
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44
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Leung MP, Mok CK, Lau KC, Lo R, Yeung CY. The role of cross sectional echocardiography and pulsed Doppler ultrasound in the management of neonates in whom congenital heart disease is suspected. A prospective study. Br Heart J 1986; 56:73-82. [PMID: 3524633 PMCID: PMC1277388 DOI: 10.1136/hrt.56.1.73] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The application of cross sectional echocardiography and pulsed Doppler ultrasound to the management of symptomatic neonates with suspected congenital heart disease was studied in 96 consecutive cases. The ability of echocardiography to establish a complete and accurate diagnosis and a correct management plan was evaluated. Sequential segmental analysis of data from cardiac catheterisation and necropsy identified 536 cardiovascular anomalies. Of the 536 anomalies 512 were correctly diagnosed by echocardiography (sensitivity 95.5%). Seven false positive echocardiographic diagnoses were made (specificity 98.6%). Nearly all the missing diagnoses and all the false positive diagnoses made by echocardiography were extracardiac vascular anomalies. Normal cardiovascular anatomy was at all times correctly identified by echocardiography. In 12 babies (12.5%) a management plan could not be established because of inconclusive echocardiographic findings. Of the 84 proposed plans based on the echocardiographic findings, eight were found to be inappropriate after catheterisation. Thus, 76 babies (79.2%) could have been correctly managed without cardiac catheterisation. The combination of cross sectional echocardiography and pulsed Doppler ultrasound not only allows diagnosis of congenital cardiac anomalies in most neonates but can facilitate appropriate clinical management. Only a minority of neonates with suspected congenital heart disease require cardiac catheterisation and angiography.
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45
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Abstract
A 24 year old woman with myasthenia gravis suffered an antepartum exacerbation which failed to respond to increasing dosages of pyridostigmine. Thymectomy performed in the second trimester was followed by clinical improvement and full term vaginal delivery with no puerperal deterioration.
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46
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Abstract
Analysis was made of 20 patients with endobronchial tuberculosis proven by fiberoptic bronchoscopy and bronchial biopsy. Unlike prechemotherapy reports, the disease affects the older age group and more men. Only one half of the patients had fever, and the characteristic localized wheeze was found in 15 percent of cases. Chest roentgenogram showed typical collapse-consolidation in most cases; however, it was clear in 20 percent of patients. Sputum/smear was negative for AFB in 85 percent of patients. When the gelatinous granulation tissue was not found during bronchoscopy, a diagnosis of bronchogenic carcinoma was made incorrectly in 30 percent of patients. At a mean period of 27 months postchemotherapy, all 12 patients recalled for study developed bronchostenosis proven by bronchoscopy/bronchography except one. Noninvasive methods such as chest roentgenogram and flow-volume loops were insensitive for detection of stenosis. Steroid therapy probably did not influence outcome of tuberculous endobronchitis.
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Leung MP, Mok CK, Lo RN, Lau KC. An echocardiographic study of perimembranous ventricular septal defect with left ventricular to right atrial shunting. Br Heart J 1986; 55:45-52. [PMID: 3947481 PMCID: PMC1232067 DOI: 10.1136/hrt.55.1.45] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Twenty nine patients with isolated perimembranous ventricular septal defects were investigated by M mode, cross sectional, and pulsed Doppler echocardiography. Tricuspid valve anomalies were present in all six patients with a left ventricular-right atrial shunt but in only six (26%) of 23 patients who had interventricular shunts only. Systolic flutter of the tricuspid valve was shown in five (83%) of the six patients with a ventriculoatrial shunt but not in the other patients. Systolic turbulence in both the right ventricle and right atrium was detected by Doppler echocardiography only in patients with ventriculoatrial shunting. A perimembranous ventricular septal defect with left ventricular to right atrial shunt can be diagnosed by its combined M mode, cross sectional, and pulsed Doppler echocardiographic features.
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Leung MP, Mok CK, Lo R, Lau KC. Atrioventricular septal defect after surgical resection of a subaortic shelf. Pediatr Cardiol 1986; 7:205-7. [PMID: 3822866 DOI: 10.1007/bf02093181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Left ventricular to right atrial (LV-RA) communications are rare septal defects. The majority of them are congenital in origin and acquired defects are exceedingly rare. The causes of acquired LV-RA communications include chest trauma, infective endocarditis, and valvar replacement. This report describes a case of direct LV-RA and interventricular communications occurring three months after excision of a subaortic shelf.
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Mok CK, Boey J, Wang R, Chan TK, Cheung KL, Lee PK, Chow J, Ng RP, Tse TF. Warfarin versus dipyridamole-aspirin and pentoxifylline-aspirin for the prevention of prosthetic heart valve thromboembolism: a prospective randomized clinical trial. Circulation 1985; 72:1059-63. [PMID: 3899404 DOI: 10.1161/01.cir.72.5.1059] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In a prospective, randomized, parallel study, two regimens of platelet-suppressant therapy (PST)--dipyridamole-aspirin and pentoxifylline-aspirin--were compared with standard oral anticoagulation with warfarin in the prevention of prosthetic heart valve thromboembolism. In the entire group of 254 patients followed for 395.6 patient-years, the thromboembolic rate was significantly less in the warfarin group (warfarin vs dipyridamole-aspirin, p less than .005; warfarin vs pentoxifylline-aspirin, p less than .05). Subgroup analysis disclosed that, in patients with isolated mitral valve replacement, warfarin was superior to both of the PSTs with respect to the prevention of thromboembolism (warfarin vs dipyridamole-aspirin, p = .005; warfarin vs pentoxifylline-aspirin, p less than .05). Furthermore, a significant number of our patients could not tolerate the antiplatelet agents. However, in the rare situation in which repeated significant bleeding occurs despite careful adjustment of the dosage of warfarin, PST may be an acceptable alternate method of thromboembolism prophylaxis.
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Abstract
Within a period of 15 months, we encountered five patients with outlet strut fracture of the Björk-Shiley convexoconcave mitral valve prosthesis. All of the patients had acute failure of the left side of the heart and pulmonary edema. The diagnosis was made by review of the chest roentgenogram which showed features of pulmonary edema; both the outlet strut and the tilting disc were missing from the mitral prosthesis. The "missing" components might be found in the left side of the heart or in the course of the thoracic aorta. Emergency reoperation was carried out on three patients, and there were two survivors. It is essential to recognize this potentially fatal complication and undertake immediate surgical intervention. We performed the original valvular replacement operations in four of the five patients. The probability of outlet strut fracture occurring in our series of 237 patients with a Björk-Shiley convexoconcave mitral valve prosthesis is 1.69%, or 0.076 per 100 patient months.
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