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Journal Article↗
Biomedical subjects
J Au
Publications and source records attributed to J Au.
The effect off-pump coronary artery bypass surgery on in-hospital mortality and morbidity.
OBJECTIVE: Off-pump coronary artery bypass (OPCAB) surgery is being increasingly reported to show better outcomes compared to conventional on bypass grafting. We examined the effect of OPCAB on in-hospital mortality and morbidity, while adjusting for patient and disease characteristics, in four institutions in the North West of England. METHODS: Between April 1997 and March 2001, 10,941 consecutive patients underwent isolated coronary artery bypass surgery at these four institutions. Of these, 7.7% were performed off-pump. We used logistic regression to examine the effect of OPCAB on in-hospital mortality and morbidity after adjusting for potentially confounding variables. RESULTS: The crude odds ratio (OR) for death (off-pump versus on-pump coronary bypass grafting) was 0.48 (95% confidence interval, CI 0.26-0.92; P=0.023). After adjustment for all major risk factors, the OR for death was 0.59 (95% CI 0.31-1.12; P=0.105). Off-pump patients had a substantially reduced risk of post-operative stroke (0.6 versus 2.3%, respectively; adjusted OR 0.26 (95% CI 0.09-0.70; P=0.008) and a significant reduction in post-operative hospital stay. Other morbidity outcomes were similar in both groups. CONCLUSIONS: Off-pump coronary artery bypass incurs no increased risk of in-hospital mortality. In contrast, there is a significant reduction in morbidity in patients undergoing off-pump coronary bypass grafting when compared to that performed on cardiopulmonary bypass.
Aged↗
A study of demographic changes under sustained below-replacement fertility in Hong Kong SAR.
The total fertility in Hong Kong SAR fell continuously below replacement in the past two decades and reached a level of 0.98 in 1998. The rate in 1981 was close to replacement at 1.93. In this paper the theoretical outcomes of long-lasting below-replacement fertility are identified with a view to gaining some analytical insight into the situation, where the population is experiencing such a striking demographic trend. In the absence of migration, Hong Kong SAR will see its population start to decline between 2008 and 2038, if the future course of fertility falls within these 'bounds'. Concurrently, the aging of population will be reaching unprecedented proportions. Should fertility remain at the present below-replacement level, i.e. the worse-case scenario, the proportion of population aged 65 years or older would increase to 44 per cent, and those aged under 15 years would decrease to six per cent, by 2048. As a result, the potential labour supply (those aged 15-64 years) would dwindle to only 50 per cent of the population, suggesting that there would be less than one person potentially working to support one dependent (who is likely to be a person aged 65 years or older). The socio-economic consequences of population aging are discussed. By analysing net immigration in the demographic process in the past, the way in which replacement migration would help alleviate the problem of population decline and population aging is also discussed.
Adolescent↗
Coronary artery bypass surgery after previous pneumonectomy-two case reports.
Coronary artery surgery after previous pneumonectomy should be considered a high risk procedure. We describe two cases with associated morbidity and mortality. Pathogenetic mechanisms are discussed.
Contraindications↗
Changes in collagenases and TGF-beta precede structural alterations in a model of chronic renal fibrosis.
BACKGROUND: To study the role of collagenases and transforming growth factor-beta (TGF-beta) in the genesis of interstitial fibrosis, we used the model of bromoethylamine (BEA)-induced papillary necrosis, which is known to lead over a period of 1 to 12 months to interstitial fibrosis and renal insufficiency. METHODS: Rats were injected with BEA, and urine and kidney tissue (cortex and medulla) were collected after 1, 2, 3, 7, and 30 days. One kidney was perfused and fixed for morphological studies and immunostained for collagen type I, III, and IV. The other kidney was used to prepare cortex and medulla extracts for gelatinases (by fluorometric and zymographic techniques), tissue inhibitors of metalloproteinase-1 (TIMP-1), and TIMP-2 (by enzyme-linked immunosorbent assay, ELISA) and TGF-beta1 (by ELISA). RESULTS: Albuminuria and interstitial fibrosis were present in BEA rats by day 7, which continued until day 30. Immunocytochemical staining for collagen types showed that collagen III and IV increased in the interstitium by day 30, but collagen I remained unchanged. Gelatinase activity in the medulla decreased by 57% compared with control by day 2 and remained low until day 30. In the cortex, gelatinase activity remained unchanged between 0 and 7 days after BEA but decreased by 72% by day 30. TIMP-1 and TIMP-2 were decreased by 80% compared with day 0 in both the medulla (by day 1) and cortex (by day 2) and remained low up to day 30. TGF-beta1 immunoreactivity increased progressively until day 2 in the medulla (16-fold higher than control) and day 3 in the cortex (8-fold higher than control) and returned to control level by day 3 in the medulla and by day 30 in the cortex. Two days after BEA injection, the mRNA for TGF-beta1 was increased eightfold in the cortex and 12-fold in the medulla, and it remained high for up to 30 days. CONCLUSIONS: The fibrosis that follows papillary necrosis is associated with both high TGF-beta1 expression and depressed gelatinolytic activity.
Animals↗
The use of 99Tcm-DTPA aerosol and caesium iodide mini-scintillation detectors in the assessment of lung injury during cardiopulmonary bypass surgery.
Lung injury is a well-documented adverse effect of cardiopulmonary bypass. The mechanism of injury is not fully understood, but pulmonary hypoxia may be a factor. Post-operative pulmonary epithelial permeability (PEP) in ventilated versus non-ventilated lungs was measured within 2 h of return to the intensive care unit using a 99Tcm-diethylenetriamine pentaacetate aerosol technique. A portable scintillation detector system was required. Sodium iodide detectors have been used previously with this technique but are cumbersome. This study used mini caesium iodide detectors (Oakfield Instruments, Oxon, UK), which can be attached directly to the patient and are more suited to the intensive care setting. The clearance half-time from lung to blood (T1/2LB) was measured in 31 patients (62 lungs). The mean (+/- S.E.M.) clearance half-times were 42.3 +/- 2.7 and 45.7 +/- 3.8 min for non-ventilated and ventilated lungs respectively, with a mean difference of 3.4 +/- 3.1 min (P > 0.05). We conclude that, using this technique, no significant difference in PEP is observed between ventilated and non-ventilated lungs in patients undergoing cardiopulmonary bypass.
Adult↗
Special problems of the asthmatic patient.
Environmental factors and physical activity present special problems for the asthmatic patient. Bronchoconstriction due to workplace exposure is one of the most common forms of occupational lung disease and has similar pathogenic mechanisms to nonoccupational asthma. Diagnosing occupational asthma may be difficult because the association between symptoms during or after work and a causative agent may be obscure. Nevertheless, it is important to recognize occupational asthma because even trace amounts of the causative agent may trigger bronchoconstriction, and the affected employee must almost always avoid exposure. Bronchoconstriction induced by exercise has affected the lifestyles of many asthmatic patients and has created special problems for numerous accomplished athletes. Although exercise-induced asthma (EIA) characteristically occurs immediately after cessation of exertion, a recent study suggests that it may sometimes begin during sustained exertion. Asthmatic patients who participate in winter sports are particularly susceptible to EIA. Vocal cord dysfunction in athletes who participate in intense competition can mimic EIA. In addition to beta-agonists used immediately before exercise, newer drugs that show promise in the treatment of EIA include the leukotriene inhibitors and furosemide. Asthmatic patients are susceptible to extremes in atmospheric pressure and have increased risk of barotrauma and arterial gas embolism during scuba diving. During longer stays at high altitude, however, asthmatic patients appear to have attenuated bronchial responsiveness.
Adrenergic Agonists↗
Myocardial perforation associated with the use of the Gensini ventriculography catheter.
We describe myocardial perforation during left ventriculography using the Gensini catheter in two patients with aortic valve disease. In each case this occurred despite careful catheter positioning and prior 'test' injection of contrast agent. The use of the Gensini catheter for left ventriculography in this circumstance is seriously questioned.
Aged↗
A technique for studying the function of an isolated, perfused and ventilated lung in a rat model.
We describe a technique which allows perfusion of an isolated, ventilated rat lung with an extracorporeal veno-venous circuit from a support animal. This model provides stable and reliable function of the isolated lung for up to 3 h, thus overcoming some of the disadvantages of previous models. It may prove a potentially useful model for assessing ischaemic lung injury.
Animals↗
Airway complications after pulmonary transplantation.
Airway healing was identified initially as one of the fundamental limitations of pulmonary transplantation. Recent experience suggests that this is no longer the case. A series of 67 pulmonary transplants (27 heart-lung, 31 single-lung, 9 double-lung) in 66 patients surviving more than 14 days was reviewed with reference to airway complications. There were 75 anastomoses at risk in two groups as defined by anastomotic location: 47 anastomoses in 38 patients in a bronchial group and 28 anastomoses in 28 patients in a tracheal group. A total of 10 airway complications developed (stenosis in 5 patients [4 bronchial group, 1 tracheal group] and dehiscence in 5 patients [1 bronchial group, 4 tracheal group]) causing two airway-related deaths (2 of 67) in the series. However, no significant correlation could be identified with either ischemic interval, suture technique, type of wrap, preoperative or postoperative steroid therapy, or date of first rejection episode. Airway complications are no longer a major limitation of pulmonary transplantation. Satisfactory airway healing can occur in both the presence of steroid therapy and the absence of an omental or pericardial wrap.
Adolescent↗
Pneumonectomy for bronchogenic carcinoma in the elderly.
We have reviewed 70 consecutive elderly patients (70 years or older) who underwent pneumonectomy for bronchogenic carcinoma, in order to evaluate morbidity, mortality, and long-term survival. The majority of the patients had stage II (n = 32) or III (n = 25) disease. Fifteen deaths occurred in the peri-operative period (21%). Pre-operative factors associated with peri-operative death included a history of ischaemic heart disease (P = 0.001) and right-sided tumour (peri-operative mortality for right pneumonectomy = 37%, left pneumonectomy = 6%, P = 0.001). Poor lung function (as assessed by pre-operative spirometry), peripheral vascular disease, cerebrovascular disease, diabetes mellitus, and hypertension were not significant risk factors for peri-operative death. Post-operatively, the requirement for ventilation, or the development of post-operative myocardial infarction, adult respiratory distress syndrome and respiratory failure were significantly associated with peri-operative death. Over 60% of the patients developed one or more complications. The absolute survival rates for operative survivors were 51% and 27% at 1 and 5 years, respectively (stage I, 60% and 40%; stage II, 63% and 33%; stage III 33% and 14%). The absolute overall survival rates were 40% and 21% at 1 and 5 years, respectively. We conclude that pneumonectomy is justified in elderly patients but right-sided lesions and ischaemic heart disease should be considered as relative contra-indications.
Aged↗
Heart-lung transplantation combined with correction of interrupted aortic arch.
We describe a new technique for heart-lung transplantation in a patient with interrupted aortic arch. The operation was performed in a 21-year-old patient with situs solitus, double-inlet left ventricle, transposition of great arteries, type A interrupted aortic arch, and pulmonary hypertension. One-stage correction of interrupted aortic arch was undertaken using recipient ductal and pulmonary arterial tissues. The early postoperative course was uneventful, with clinical and radiological evidence of satisfactory result. We conclude that it is entirely feasible to undertake heart-lung transplantation in the presence of interrupted aortic arch using this technique, which requires no period of circulatory arrest and results in a tension-free anastomosis.
Adult↗
Upper gastrointestinal dysmotility in heart-lung transplant recipients.
Recipient pneumonectomy and the necessity for meticulous hemostasis in heart-lung transplantation can result in injury to the vagus nerves as they course through the posterior mediastinum, with consequent delay in gastric emptying. This has been reported to lead to chronic aspiration and associated pulmonary sequelae. To study the association between delayed gastric emptying, bronchiectasis, and bronchiolitis obliterans after heart-lung transplantation, we performed esophageal manometry, 24-hour pH monitoring, and radioisotopic gastric emptying in 10 patients who underwent heart-lung transplantation. Three patients had grossly delayed liquid and solid emptying that was compatible with complete vagotomy. Six other patients had delayed liquid but normal solid emptying--an unexplained finding that is the reverse of what one would expect from vagal injury. Two of these 9 patients had esophageal dysmotility, but none demonstrated gastroesophageal reflux. One remaining patient had faster than normal gastric emptying for both solids and liquids. Of the 10, 2 patients have radiologic changes of bronchiectasis and 3 have biopsy evidence of obliterative bronchiolitis. There is no relationship between these sequelae and the occurrence of esophageal dysmotility, gastroesophageal reflux, or vagotomy. We conclude that gastric emptying abnormalities can occur after heart-lung transplantation, but such abnormalities are not associated with gastroesophageal reflux and the development of pulmonary sequelae, as previously reported.
Adult↗
Orthotopic heart transplantation for congenital heart disease. Technical considerations.
Heart transplantation for congenital heart disease poses unique problems because of structural anomalies and previous corrective and palliative surgery. In the period between May 1985 and February 1992 a total of 231 orthotopic heart transplants were performed at our hospital -22 of these procedures were carried out in patients with congenital heart disease. The patient's ages ranged from 1 month to 51 years (median 10 years). There were 13 patients in the paediatric group (under 16 years) and 9 patients in the adult group (16 years or older). The diagnoses included univentricular connections (8 patients), complex morphology (4 patients), congenitally corrected transposition of the great arteries (TGA) (3 patients), hypoplastic left heart syndrome (2 patients), Fallot's tetralogy, tricuspid atresia, TGA, pulmonary atresia with intact ventricular septum and atrial septal defect (ASD) and ventricular septal defect (VSD). These patients had protected pulmonary circulation due to previous surgery or as a result of intrinsic pulmonary stenosis. Seventeen patients (77%) had undergone 29 prior operations (21 palliative and 8 corrective) including Blalock-Taussig shunts, pulmonary artery (PA) banding, ASD and VSD repair, Fontan procedure and Mustard operation. There were 2 early deaths in the paediatric group and 4 early deaths in the adult group, but no late deaths. The cause of death was multi-organ failure following uncontrollable haemorrhage in 3 patients, sepsis in 1 patient and donor organ failure in the 2 paediatric patients. Specific surgical manoeuvres were required to create the normal anatomical configuration. These included the rerouting of venous circulation, pulmonary artery reconstruction and atrial septation. Adequate donor tissue was taken to permit satisfactory reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Immunization against the HIV-associated anti-self, anti-CD4 cytotoxic T lymphocyte.
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Adult↗
Post-infarction communication between a left ventricular aneurysm and the right atrium.
A 70-year-old patient presented with ventricular tachycardia and left ventricular failure. He was found to have a communication between a posterior left ventricular aneurysm and the right atrium. The causal myocardial infarction had been silent. This defect was satisfactorily closed at operation from which he made an uneventful recovery. This is the first report of a left ventricular-right atrial communication developing in association with ischaemic heart disease and highlights the role of transoesophageal echocardiography in the diagnosis and surgical management of such a condition.
Aged↗
Paediatric cardiac transplantation with steroid-sparing maintenance immunosuppression.
In order to determine the results of steroid-sparing maintenance immunosuppression in paediatric patients who have undergone orthotopic heart transplantation (OHT), a retrospective study was undertaken in 12 children and five infants (median age 3.5 years). Preoperative diagnoses were cardiomyopathy in seven and congenital heart disease in 10 patients. Immunosuppression was induced by cyclosporin, azathioprine, methylprednisolone, and antihuman lymphocyte immune globulin. It was maintained with cyclosporin and azathioprine. After induction, five patients received no further steroids. The remainder, except one, required only pulses for rejection (13 episodes or 0.51 episodes/patient year). Long term complications included hypertension in six, and renal impairment in three children. There were no early or late deaths from infection. Actuarial survival was 94% at one year. Of the children followed up for more than one year, all demonstrated an increase in height SD scores (mean (SD) -2.15 (1.35) to -1.15 (1.16)). We conclude that a steroid-sparing maintenance immunosuppression regimen can be successfully employed in paediatric OHT, and that significant catch-up growth can be achieved postoperatively.
Azathioprine↗