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Biomedical subjects

Sharif Al-Ruzzeh

Publications and source records attributed to Sharif Al-Ruzzeh.

At least 19 recordsLinked to original sources
PubMed2006

Effect of off-pump coronary artery bypass surgery on clinical, angiographic, neurocognitive, and quality of life outcomes: randomised controlled trial.

OBJECTIVE: To compare the clinical, angiographic, neurocognitive, and quality of life outcomes of off-pump coronary artery bypass surgery with conventional coronary artery bypass grafting surgery using cardiopulmonary bypass. DESIGN: Randomised controlled clinical trial. SETTING: Tertiary cardiothoracic centre in Middlesex, England. PARTICIPANTS: 168 patients (27 women) requiring primary isolated coronary artery bypass grafting surgery. INTERVENTIONS: Patients were randomised to conventional coronary artery bypass grafting surgery using cardiopulmonary bypass (n = 84) or off-pump coronary artery bypass surgery (n = 84), carried out by one surgeon. Angiographic examination was carried out at three months postoperatively. Neurocognitive tests were carried out at baseline and at six weeks and six months postoperatively. MAIN OUTCOME MEASURES: Clinical outcome, graft patency at three months, neurocognitive function at six weeks and six months, and health related quality of life. RESULTS: Graft patency was evaluated by angiography in 151 (89.9%) patients and was similar between the cardiopulmonary bypass and off-pump groups (risk difference - 1%, 95% confidence interval - 5% to 4%), with the off-pump group considered the treatment group. Patients in the off-pump group required fewer blood transfusions (1.7 units v 1.0 unit, P = 0.02), shorter duration of mechanical ventilation (7.7 hours v 3.9 hours, P = 0.03), and shorter hospital stay (10.8 days v 8.9 days). Scores for neurocognitive function showed a significant difference in three memory subtests at six weeks and two memory subtests at six months in favour of the off-pump group. CONCLUSIONS: Patients who underwent off-pump coronary artery bypass surgery showed similar patency of grafts, better clinical outcome, shorter hospital stay, and better neurocognitive function than patients who underwent conventional coronary artery bypass grafting surgery using cardiopulmonary bypass.

Cognition Disorders↗
PubMed2006

A technical failure changes a Y-graft into a C-conduit causing steal syndrome.

Y-grafting is a common coronary grafting technique for performing composite coronary grafts. The outcome and efficacy of this technique have not been studied in detail in the literature. We report a case of an occlusion in the proximal limb of a Y-graft, changing it into a C-shaped conduit and causing a steal syndrome. Our aim is to raise the level of caution when performing this type of composite graft and to suggest how this complication can be managed postoperatively.

Aged, 80 and over↗
PubMed2006

Effect of myocardial reperfusion on the release of nitric oxide after regional ischemia: an experimental model of beating-heart surgery.

Off-pump coronary artery bypass surgery is increasing in popularity worldwide. However, very little is known about the effect of regional myocardial ischemia-reperfusion on nitric oxide release. In an animal model mimicking off-pump bypass, male Sprague-Dawley rats (350-450 g) were mechanically ventilated under general anesthesia. After left lateral thoracotomy, the animals underwent occlusion of either the left anterior descending artery (for 3, 5, 75, 10, 12.5, 15, or 20 minutes) or the circumflex artery (for 5, 10, or 15 minutes). Twenty-four hours after reperfusion, heart tissue was stained for determination of the area at risk and the infarcted area. Blood samples obtained before ischemia, 10 minutes after reperfusion, and 24 hours after reperfusion were analyzed for plasma concentrations of nitric oxide. After occlusion of the left anterior descending artery, the size of the infarcted area increased dramatically as the duration of occlusion increased, and was significantly larger after 12.5, 15, or 20 minutes of occlusion than after 3 minutes. After occlusion of the circumflex artery, the size of the infarcted area increased steadily and was significantly larger after 15 minutes of occlusion than after 5 minutes. There was no significant correlation between the duration of coronary occlusion and the plasma concentration of nitric oxide: 10 minutes after reperfusion, this concentration was significantly lower than that before ischemia, but it was twice the baseline level 24 hours after reperfusion. We concluded that the duration of regional ischemia did not affect the plasma concentration of nitric oxide in the systemic circulation.

Animals↗
PubMed2005

Functional renal outcome in on-pump and off-pump coronary revascularization: a propensity-based analysis.

BACKGROUND: Since the advent of off-pump coronary artery bypass grafting (OPCAB), comparisons have been made between it and on-pump coronary artery bypass grafting. Some observe a lesser incidence of acute renal failure requiring renal replacement therapy with OPCAB whereas others do not. The objective was to compare the occurrence of renal adverse outcome between on-pump coronary artery bypass grafting and OPCAB. Renal adverse outcome was defined as minor (20% increase in serum creatinine from preoperative) or major (composite end point of postoperative serum creatinine >200 mumol/L or postoperative mechanical renal support). METHODS: The study was based on 2,041 patients with no known preoperative renal disease having first-time isolated coronary artery bypass grafting of multiple coronary arteries between January 2001 and November 2003, at St. Mary's Hospital, Harefield Hospital, and Hammersmith Hospital, in West London; 1,224 patients had on-pump coronary artery bypass grafting and 817 patients had OPCAB. Selection bias for surgical technique was addressed by calculating the propensity score for each patient and using it as an independent variable for adjustment in the multivariate analysis. Univariate and multivariate ordered logistic regressions were used to identify factors associated with renal adverse outcome ordered as none, minor, and major. RESULTS: The number of grafts was 3.22 +/- 0.82 for the on-pump coronary artery bypass grafting group and 3.35 +/- 0.95 for the OPCAB group. On-pump coronary artery bypass grafting and increasing age were found to be the strongest independent predictors (p < 0.001) of renal adverse outcome. Other independent predictors included hypertension (p = 0.005), diabetes (p = 0.032), and preoperative serum creatinine (p = 0.001). A left ventricular ejection fraction of 0.30 to 0.49 (p = 0.099) and an ejection fraction of 0.50 or greater (p < 0.001) were associated with decreased risk compared with patients with an ejection fraction of less than 0.30. Interestingly, the use of non-left internal mammary arterial conduits significantly decreased the likelihood of renal adverse outcome (p = 0.034). CONCLUSIONS: The results of this propensity-based study show that the OPCAB technique may reduce the risk for minor and major renal adverse outcome after coronary artery bypass grafting.

Aged↗
PubMed2005

Dobutamine improves thoracic aortic blood flow during off-pump coronary artery bypass surgery: results of a prospective randomised controlled trial.

OBJECTIVE: Dobutamine is commonly used to improve ventricular performance in cardiac surgery. The aim of this prospective randomised controlled study was to assess the effectiveness of using low doses of dobutamine during off-pump coronary artery bypass (OPCAB) surgery in order to reduce haemodynamic compromise due to heart displacement. METHODS: Thirty-two patients undergoing elective coronary artery bypass grafting (CABG) surgery using OPCAB technique for more than two vessels were approached and recruited. We analysed the changes in the thoracic aortic blood flow (TABF) during OPCAB using transoesophageal Doppler and by other conventional monitoring methods as cardiac output, invasive pulmonary and radial pressures and mixed venous oxygen saturation. RESULTS: The two groups were similar in preoperative characteristics. No postoperative complications were observed in the study patients. The heart rate, right atrial pressure, cardiac output measured by thermodilution and TABF changed significantly during the procedure. Also significant changes in descending thoracic aortic diameter were observed. The postoperative creatinine was significantly lower in the dobutamine group (P=0.04). Dobutamine was found responsible for the improvement in the descending TABF (P=0.006). CONCLUSIONS: This study showed that intra-operative intravenous infusion of dobutamine at 5 microg/kg per min in routine OPCAB patients safely increased cardiac output even without such changes been detected by conventional monitoring methods.

Analysis of Variance↗
PubMed2004

Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients.

Several recent studies have highlighted the potential benefits of using off-pump coronary artery bypass (OPCAB) surgery, particularly in high-risk patients. The aim of this meta-analysis is to assess the effect of OPCAB on the incidence of stroke compared with coronary artery bypass grafting using cardiopulmonary bypass (CPB) in elderly patients. We performed a meta-analysis of all observational studies, published in MEDLINE between 1999 and 2002 and a comparison between the OPCAB and CPB techniques in elderly patients was performed with the outcome of interest being the incidence of stroke. Elderly patients were defined as those aged 70 years or older. Nine studies are included in the meta-analysis. The total number of subjects included was 4,475 patients, of which, 1,253 underwent OPCAB (28%) and 3,222 (72%) underwent CPB. The meta-analysis showed that the OPCAB technique was associated with significantly lower incidence of stroke in elderly patients compared with the CPB technique (1% vs 3%), with an odds ratio of 0.38% to 95% (CI, 0.22 to 0.65). We did not identify any significant heterogeneity and funnel plot asymmetry between the studies included in the meta-analysis. Meta-regression analysis including variables predicting stroke, mortality, and study characteristics did not show any associations affecting the calculated odds ratio of stroke. Despite the fact that this is a meta-analysis of observational studies and adjustment for differences in baseline risk factors between OPCAB and CPB patients was not possible, we believe that this study suggests that the OPCAB technique might be associated with reduced incidence of stroke in the elderly patients undergoing coronary artery bypass grafting.

Aged↗
PubMed2004

Do off-pump techniques reduce the incidence of postoperative atrial fibrillation in elderly patients undergoing coronary artery bypass grafting?

BACKGROUND: Atrial fibrillation is the most common postoperative complication in patients undergoing coronary artery bypass grafting (CABG) with advancing age having been shown to have a significant association with its incidence. This study aims to assess whether off-pump coronary artery bypass (OPCAB) reduces the incidence of atrial fibrillation in elderly patients. METHODS: A meta-analysis of all observational studies reporting a comparison between the two techniques in elderly patients (> 70 years) between 1999-2003 was performed. The primary outcome of interest was the incidence of postoperative atrial fibrillation. The quality of each study was evaluated by examining three items: patient selection, matching of the off-pump and cardiopulmonary bypass patient groups, and assessment of outcome. Meta-regression analysis was undertaken to see the effects of study size and quality on the calculated odds ratio. RESULTS: Eight studies fulfilled our inclusion criteria, all of which were nonrandomized. In total the studies identified 3017 subjects, of which 764 had off-pump surgery (25%) and 2253 underwent cardiopulmonary bypass (75%). Meta-analysis showed that after off-pump surgery there was a significantly lower incidence of postoperative atrial fibrillation in these patients (odds ratio 0.70, 95% confidence interval [CI] 0.56-0.89). Meta-regression analysis including study characteristics did not show any associations affecting the calculated odds ratio of atrial fibrillation. CONCLUSIONS: Our study demonstrates a reduced incidence of postoperative atrial fibrillation in an elderly population with off-pump as compared with cardiopulmonary bypass techniques. We appreciate, however, that our statistical analysis uses nonrandomized published data and that the results must be treated with caution. If this finding is confirmed by a large-scale randomized trial, it has significant implications on the operative strategy employed for this patient group.

Aged↗
PubMed2004

Analysis of thoracic aortic blood flow during off-pump coronary artery bypass surgery.

OBJECTIVES: The non-invasive monitoring of thoracic aortic blood flow (TABF) during off-pump coronary artery bypass (OPCAB) surgery is becoming more commonly used and proved to be invaluable in the early detection of haemodynamic compromise due to heart displacement. The aim of this study was to analyze the changes in the TABF during OPCAB using transoesophageal Doppler and compare them with the changes observed by other monitoring methods as cardiac output, invasive pulmonary and radial pressures and mixed venous oxygen saturation. METHODS: The measurements obtained from classic haemodynamic monitoring methods including the radial artery line and the pulmonary artery catheter with continuous monitoring of the cardiac output and mixed venous blood oxygen saturation were compared to the measurements of TABF obtained from a transoesophageal Doppler probe in 15 consecutive patients who underwent OPCAB surgery. RESULTS: The TABF decreased significantly during the construction of coronary anastomoses from 3.42 +/- 0.94 l/min (baseline) to 2.2 +/- 0.8 l/min during the first coronary anastomosis and then to 2.14 +/- 1.12 l/min during the second coronary anastomosis (F=4.29, P=0.008). TABF returned to the baseline values (2.85 +/- 1.19 l/min) at chest closure. The cardiac output measurement showed no significant decrease compared to baseline. CONCLUSIONS: Low TABF occurred without significant changes in the measurements obtained from classic haemodynamic monitoring methods during OPCAB surgery. This finding could be of vital importance in helping improve the monitoring and consequently the management of patients undergoing OPCAB surgery.

Analysis of Variance↗
PubMed2004

Does off-pump coronary artery bypass reduce the incidence of post-operative atrial fibrillation? A question revisited.

Atrial fibrillation (AF) is the most common post-operative complication in patients undergoing coronary artery bypass grafting, with an increased incidence associated with advancing age. This study aims to determine whether off-pump coronary artery bypass (OPCAB) reduces the incidence of AF in a generalized population (mean age <70 years). A meta-analysis was performed including all randomised and propensity score matched non-randomised studies published between 2001 and 2003 reporting a comparison between the two techniques in a generalised patient group (average age <70 years). The primary outcome of interest was post-operative AF. Sensitivity analysis was performed to evaluate consistency of the calculated treatment effect. Fourteen studies fulfilled our inclusion criteria, including a total of 16,505 subjects. The incidence of AF was 19% (1612/8265) in the off-pump group versus 24% (1976/8240) in the on-pump group. When considering only the 11 randomised studies (2207 subjects), we found a significant reduction in the incidence of post-operative AF in the off-pump group using a random-effect model (odds ratio (OR)=0.60, 95% confidence interval (CI)=0.45-0.82, and chi-square of heterogeneity=18.02, P=0.05). Sensitivity analysis highlighted one randomised study causing funnel plot asymmetry, exclusion of which resulted in a significant reduction in the incidence of post-operative AF in the off-pump group (OR=0.71, 95% CI=0.57-0.90), with a non-significant heterogeneity of 3.91 (P=0.92). When only studies of high quality were considered (898 patients), no significant difference was seen between on and off-pump groups (OR=0.78, 95% CI=0.57-1.07, and heterogeneity=0.53, P=0.91). This may be due to small number of patients in this group. Our results suggest that although OPCAB surgery may reduce the incidence of post-operative AF in a generalised population (age <70 years) this finding is not clearly supported by high quality randomised trials. Although previous evidence suggests that the incidence of post-operative AF is reduced in an elderly population (>70 years) with off-pump surgery, our results show that the evidence is less clear in a younger population group. The question of whether off-pump surgery in this patient group results in a lower rate of post-operative AF remains to be answered by further high quality randomised research.

Adult↗
PubMed2004

Are wound healing disturbances and length of hospital stay reduced with minimally invasive vein harvest? A meta-analysis.

Minimally invasive great saphenous vein harvest for coronary artery bypass grafting aims to reduce post-operative leg-wound related morbidity. In a meta-analysis of randomised trials we have shown leg wound infection rates to be significantly lower in patients undergoing minimally invasive harvest. This study aims to use meta-analysis to compare the two techniques with regards to non-infective wound healing disturbances (NIWHD) (wound drainage, haematoma, dehiscence, necrosis, need for surgical debridement, and seroma formation). A meta-analysis of all studies published between 1995 and 2002 reporting a comparison between the two techniques was performed. Primary outcomes of interest were the six wound healing disturbances mentioned above and length of hospital stay. Heterogeneity was assessed using graphical exploration and sensitivity analysis with subgroup analysis. Twenty-seven studies published between 1997 and 2002 matched our selection criteria, with a combined total of 4953 subjects, of which 2442(49%) underwent minimally invasive harvest and 2511(51%) underwent conventional surgery. When considering only randomised studies, the total number of non-infective wound disturbances was lower in minimally invasive (4%) as compared to the conventional (13%) group (random effect OR 0.24, CI 0.16-0.38). Similar results were found when only fully matched studies were considered. The absolute risk reduction when comparing the two techniques was calculated to be 0.10, which translates to a number of patients needed to treat of 10. Length of stay was significantly reduced in the minimally invasive group in comparison to the conventional group (random effect weighted mean difference of -1.04, CI -1.92 to -0.16). Our results suggest that NIWHD all reduced with minimally invasive harvest techniques. Despite the limitations of this meta-analysis, we feel we have once again illustrated an important link between minimally invasive great saphenous vein harvest and improved tissue healing when compared to conventional open surgery. This has the potential to reduce wound-related morbidity, infection, post-operative pain, length of hospital stay, and re-admission rate.

Coronary Artery Bypass↗
PubMed2004

Methodological approach in adopting off-pump coronary artery bypass surgery in a British cardiothoracic unit: Harefield experience.

The theoretical and practical disadvantages of coronary artery bypass graft surgery using cardiopulmonary bypass with cardioplegic arrest are well reported in the literature. Encouraged by our work and others, we adopted a systematic approach to the application of off-pump coronary artery bypass surgery. We aimed to validate the non-selective use of the off-pump technique in all patients and assess the outcome in specific patient groups including: patients with ischaemic left ventricular dysfunction, female and high-risk patients. We investigated specific technical details related to off-pump surgery including: the potential effect of the distortion of the mitral valve on haemodynamic stability intraoperatively and the feasibility of sequential coronary artery bypass grafting using the off-pump technique. We also compared the outcome to the national United Kingdom performance in a risk-stratified manner. An extensive retrospective data review for comparative analysis of outcome was carried out at both local and multi-centre levels. This showed that off-pump surgery was feasible for all patients, and provided a better outcome in patients with ischaemic left ventricular dysfunction, female and high-risk patients. The distortion of the mitral valve contributed to the haemodynamic instability. In conclusion, off-pump surgery is safe and provides better outcome in specific patient groups.

Aged↗
PubMed2004

Right ventricular assist device thrombosis during biventricular heart assistance.

We report a case of total thrombosis of a right ventricular assist device in a patient during biventricular assistance. The thrombosis occurred 18 days following implantation and the right ventricular device was immediately removed without any complications. The patient was successfully transplanted after 3 months of left ventricular assistance.

Adult↗
PubMed2004

Cerivastatin does not prevent oxidative injury of human aortic endothelial cells.

The anti-atherogenic properties of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been well established in several circulatory beds. Increasing evidence suggests that statins may help attenuate ischemia-reperfusion injury, a beneficial effect that may be related to the antioxidant capabilities of statins; however, this remains controversial. We performed this study to determine whether the HMG-CoA reductase inhibitor cerivastatin can prevent oxidative stress-induced injury in cultured human aortic endothelial cells (HAEC). The HAEC were subjected to oxidative stress in the absence and presence of increasing concentrations of cerivastatin (50 nM-1,000 nM). Oxidative stress was induced by increasing concentrations of hydrogen peroxide or endogenous superoxide anions generated by the inhibition of superoxide dismutase using diethylthiocarbamate (10 mM). Cell viability and mitochondrial activity were measured by mitochondria-dependent 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) conversion. Cell morphology was also examined using light microscopy. Exposing HAEC to cerivastatin for 24 hours had no effect on cell viability using both cell morphology and MTT conversion: the HAEC incubated in 100 nM cerivastatin had 90% +/- 2.2% viability of the control. As expected, hydrogen peroxide produced a concentration-dependent decrease in cell viability. Varying concentrations of cerivastatin pretreatment for < or = 18 hours showed no protection of HAEC against hydrogen peroxide-induced injury. As a positive control, the prototype antioxidant N-acetyl-L-cysteine was cytoprotective even with the highest hydrogen peroxide concentration. Neither cerivastatin nor N-acetyl-L-cysteine protected HAEC against diethylthiocarbamate-induced oxidative injury at any concentration. In this study, cerivastatin did not protect cultured HAEC against oxidative stress induced by hydrogen peroxide or diethylthiocarbamate.

Aorta↗