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1. The impact of intraoperative cell salvage on autologous blood usage following first time coronary artery bypass grafts (CABG) – a prospective audit Rammohan KS, Gostling J, Stevens P, Jones M, Jones C, O’Keefe PA, Dunne J Department of Cardiothoracic Surgery, University Hospital of Wales and College of Medicine (UHWCM), Cardiff Background Several studies have pointed out the association of adverse outcomes with the use of allogeneic red cells. In addition, the high cost, increased demand and reduced supply dictates that there should be a valid, defined and justifiable indication for the use of allogenic blood products. Two audits at the UHWCM (1999 and 2001) showed that our usage of allogeneic blood was 90% and 65% for primary myocardial revascularization. In addition a National Audit showed our unit to be the second highest user of red cells among cardiac units audited in the UK. Objective To evaluate the effect of intraoperative cell salvage and transfusion guidelines on autologous blood usage for first time coronary artery bypass grafts. Patients and methods We undertook a prospective audit looking at 271 patients undergoing first time CABG (between October 2002 and March 2003). 113 of these patients had intraoperative cell salvage (Group 1) whilst 156 did not (Group 2). The status of two patients was unknown. Results In Group 1 (n= 113), 40 (35.5%) had allogeneic red cell transfusion while 68 (60%) received no blood. The status of 5 patients in this group was unknown (4.5%). In Group 2 (n=156), 97 patients(62%) were transfused. The mean haemoglobin values on admission to ITU were 10 for Group 1 and 9.4 for Group 2. The haemoglobin on Day 6, when the vast majority of patients were discharged, was 10.6 for Group 1 and 10.5 for Group 2. In addition, of the patients transfused red cells, 70% received less than or equal to 2 units. Usage of FFP and Platelets in the cell salvaged group (Group1) vs the non cell salvaged group (Group 2) were 17% vs 14% and 20% vs 21% respectively. Conclusion The adoption of transfusion guidelines and the use of intraoperative cell salvage decreased the use of autologous blood in our unit. In addition there was no major increase in the usage of FFP and platelets in the cell salvaged group. survival for the same periods were 63% and 37%. ›š›š 2. Risk Factors for Requirement for New Haemofiltration following Cardiac Surgery . Rammohan KS, Dunne J, Von Oppell UO. Department of Cardiothoracic Surgery, University Hospital of Wales & College of Medicine, Cardiff, United Kingdom 1
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1. The impact of intraoperative cell salvage on autologous blood usage following first time coronary artery bypass grafts (CABG) – a prospective auditRammohan KS, Gostling J, Stevens P, Jones M, Jones C, O’Keefe PA, Dunne JDepartment of Cardiothoracic Surgery, University Hospital of Wales and College of Medicine (UHWCM), CardiffBackground Several studies have pointed out the association of adverse outcomes with the use of allogeneic red cells. In addition, the high cost, increased demand and reduced supply dictates that there should be a valid, defined and justifiable indication for the use of allogenic blood products. Two audits at the UHWCM (1999 and 2001) showed that our usage of allogeneic blood was 90% and 65% for primary myocardial revascularization. In addition a National Audit showed our unit to be the second highest user of red cells among cardiac units audited in the UK. Objective To evaluate the effect of intraoperative cell salvage and transfusion guidelines on autologous blood usage for first time coronary artery bypass grafts.Patients and methods We undertook a prospective audit looking at 271 patients undergoing first time CABG (between October 2002 and March 2003). 113 of these patients had intraoperative cell salvage (Group 1) whilst 156 did not (Group 2). The status of two patients was unknown.Results In Group 1 (n= 113), 40 (35.5%) had allogeneic red cell transfusion while 68 (60%) received no blood. The status of 5 patients in this group was unknown (4.5%). In Group 2 (n=156), 97 patients(62%) were transfused. The mean haemoglobin values on admission to ITU were 10 for Group 1 and 9.4 for Group 2. The haemoglobin on Day 6, when the vast majority of patients were discharged, was 10.6 for Group 1 and 10.5 for Group 2. In addition, of the patients transfused red cells, 70% received less than or equal to 2 units. Usage of FFP and Platelets in the cell salvaged group (Group1) vs the non cell salvaged group (Group 2) were 17% vs 14% and 20% vs 21% respectively.

Conclusion The adoption of transfusion guidelines and the use of intraoperative cell salvage decreased the use of autologous blood in our unit. In addition there was no major increase in the usage of FFP and platelets in the cell salvaged group. survival for the same periods were 63% and 37%.

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2. Risk Factors for Requirement for New Haemofiltration following Cardiac Surgery.Rammohan KS, Dunne J, Von Oppell UO.Department of Cardiothoracic Surgery, University Hospital of Wales & College of Medicine, Cardiff, United KingdomBackground: Acute renal failure after cardiac surgery is a known risk factor for early mortality. This is of greater relevance in our unit which has a higher incidence of combined Coronary artery bypass graft (CABG) plus Valve surgery (14.6%) than the UK national average (7.8%).Objectives: Determination of risk factors for acute renal failure requiring haemofiltration or dialysis following cardiac surgery, and the outcome thereof.Methods: Retrospective review of all patients (N = 1,817) who underwent cardiac surgery between 1 January 2001 and 31 March 2003 (overall in-hospital mortality 3.8%). Patients who were receiving preoperative dialysis / haemofiltration for acute or chronic renal failure were excluded (N = 19; mortality 31.6%). The remaining 1,798 patients were grouped according to requirement for new postoperative haemofiltration. Risk factors identified by univariate analysis were subjected to multivariate logistic regression analysis (SPSS version 11.0).Results: Haemofiltration was required in 82 patients (4.6%) postoperatively. Categorical risk factors identified by multivariate analysis included preoperative creatinine > 200 μl/l, emergency surgery, diabetes, post operative intra-aortic balloon pump (IABP) or ventricular assist device (VAD), reopening for cardiac arrest or bleeding / tamponade (p < 0.0001). To a lesser extent, redo cardiac surgery,

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combined CABG + Valve surgery (p < 0.03), and preoperative cardiogenic shock (p < 0.05). Numerical variables identified included Euro score predicted mortality 10.23 % ± 0.54 % (standard error) versus 4.66 % ± 0.08% in patients not requiring haemofiltration, duration of cardiopulmonary bypass 151 ± 67 min. versus 107 ± 40 min., and Parsonnet score (Anova p < 0.0001). Poor outcomes associated with post-operative haemofiltration included increased in-hospital mortality of 61.0% versus 1.1% (p < 0.0001), postoperative atrial fibrillation, tracheostomy, pancreatitis (p < 0.008) and postoperative ventricular fibrillation (p < 0.03). Reopening for cardiac arrest or bleeding / tamponade was identified as a risk factor for haemofiltration and not a ‘poor outcome caused by acute renal failure’. In addition, identified risk factors for mortality in patients needing post-operative haemofiltration include poor LV function, COAD or asthma and cardiac procedures excluding isolated valve surgery (p < 0.05).Conclusions: Post cardiac surgery haemofiltration is required predominantly in higher risk patients with pre-existing co-morbid factors – especially poor baseline renal function and diabetes. Risk factors possibly amenable to therapeutic modifications include duration of cardiopulmonary bypass, need for postoperative IABP / VAD and reopening for cardiac arrest or bleeding / tamponade.

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3. Gut Ischemia following Cardiac SurgeryMr. S Hasan, Ms. J Gorden, Mr. C Ratnatunga, Mr. R Pillai, Mr. CT Lewis Derriford Hospital Plymouth John Radcliffe Hospital Oxford. Background Intra - abdominal complications occur in about 1% of the patients following cardiac surgery. Out of all these complications gut ischemia is the most dangerous and carries the highest mortality.Objective We reviewed all patients who developed gut ischemia following cardiac

surgery to get an insight into this difficult problem.Material and Method We performed a retrospective and prospective clinical review of over 4000 patients undergoing cardiac surgery between November 1997 and April 2003. Sixteen out of them develop gut ischemia postoperatively. The mean age of this group was 69 years and the male to female ratio was 3:1. The diagnosis was made on post mortem in 3 of these cases. Eleven out of them were coronary revascularisations, 2 were mitral valve replacements, 1 was an aortic valve replacement and one was a double valve procedure. Two of the cases were done without CPB. Eleven patients had generalized bowel ischemia, while 5 had localized necrosis involving the caecum in 3 and terminal ileum in 2 cases. The time of presentation ranged from the first to the fourteenth post operative day and clinical features were varied. Eight patients had been in a low output state requiring inotropes post operatively. The diagnosis was always clinical as no test is diagnostic of the condition.Results Twenty-six laparatomies were performed post cardiac surgery for abdominal complications over the study period.  Bowel ischemia was found in 13 of these patients. Four laparatomies were negative, while other pathologies were found in nine patients. Three patients of gut ischaemia were diagnosed at post mortem. Of the 16 patients with bowel infarction 11 patients were found to have extensive intestinal ischemia. Only 4 out of them underwent resection of the involved bowel and all of them died. In 5 patients localized ischemia was found involving the caecum in 3 and terminal ileum in 2. They all underwent local resections and made uneventful recoveries thereafter. Four patients with suspected intestinal ischaemia had negative laparatomies over this period. This signifies over aggressive approach to the problem.Conclusion We suggest that two separate forms of bowel ischaemia following cardiopulmonary bypass may  exist. The first is a localized type, which has a good prognosis if treated with prompt surgical

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resection. The second is a generalized type, which is related to post operative low output and carries a poor prognosis regardless of the management.

›š›š4. Mid-term results of radial and mammary arteries for complete arterial revascularisation in elective and nonelective coronary artery bypass surgeryTMF Chowdhry, M Loubani, H Vohra, M GaliñanesDivision of Cardiac Surgery/Department of Surgery, Glenfield Hospital, LeicesterObjective: The aim of this study is to evaluate the use of the radial artery alongside the internal mammary artery for complete arterial revascularisation in elective and nonelective coronary bypass graft surgery.Methods: All patients undergoing coronary artery surgery alone over a four-year period with disease of more than one coronary artery were considered for complete arterial revascularisation. Pre-operatively, all patients had an Allen’s test on the non-dominant arm and a cut off point of ten seconds was used. Results: 291 patients were revascularised using the radial and internal mammary arteries alone in Y-graft configuration. The mean age of the study population was 62.4±8.8, with a male to female ratio of 221 to 70. Elective surgery was performed in 231 patients (79%); with nonelective procedures comprising a total of 61 patients (21%). The mean number of distal anastomoses was 2.8 ± 0.8. There were seven peri-operative mortalities (2.4%), and 43 patients (14.7%) developed low cardiac output syndrome requiring inotropes with or without intra-aortic balloon pump. Forty patients (13.7%) developed postoperative supraventricular arrhythmias. There was no incidence of hand ischaemia or wound complications. After a mean follow up period of 35.4±12.5 months of 218 patients (74.9%), there were one death 24 patients required readmissions for cardiac related causes. The patients angina score were currently 0.5 ±1.0 versus 2.6± 1.4 preoperatively.

Conclusion: Total arterial revascularisation with the internal mammary and radial artery is associated with a low rate of perioperative complications and mortality, and can be safely used in both elective and nonelective bypass graft surgery with excellent clinical results.

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5. Surgical management of left ventricular aneurysm: our experienceKalkat MS, Dandekar U, Kouchkolopos C, Smallpiece C, Parmar J, Ridley P, Satur C, Levine A.North Staffordshire Royal Infirmary, Stoke on TrentBackground Coronary artery bypass surgery with or without aneurysmectomy is used to treat patients with left ventricular aneurysm (LVA). Analysis of surgical management of these patients was done to evaluate if patients benefit from these procedures.Methods Retrospective review of 91 consecutive patients who underwent LVA repair at our hospital between March 1992 and December 2002. The information was retrieved from the case notes, prospective database and follow up of patients.Results 91 patients were identified who underwent repair of LVA by various techniques. There were 76 male patients and mean age of 62 years (SD-7.5, range-39 to 78 years). The location of aneurysm was anteroapical (68%), apical (21%), posteroinferior (9.4%) and anterolateral (2%). 23 % contained thrombus. 49% of patients had angina CCS class III or greater, 54% had dyspnoea NYHA class III or greater and 2% had ventricular arrythmias. 47% had poor ejection fraction and 33 % required urgent operations. Associated procedures included aortic valve replacement in 4 patients, mitral valve repair in one patient and bypass grafts in 88 patients . Only 3 patients had isolated repair of LVA. 79% patients underwent resection and linear plication of aneurysm, 16% plication alone and 5% had repairs by Dor`s procedure. The in-hospital mortality was 11% and long term survival of 76% at a mean follow up of 39

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months. In followed up patients, out of 39 patients with preoperative NYHA class III or higher, 32( 83%) were in class II or lower and 42 of surviving patients( 62%) were free of angina .Conclusion The repair of LVA is associated with acceptable mortality, symptomatic improvement and long term survival. The improvement is more pronounced in the patients with severer symptoms.

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6. Mitochondrial KATP channels, protein kinase C and p38MAPK are differentially involved in the anti-apoptotic effect of preconditioning with ischemia and with cardioplegia in the human myocardium.Hunaid A Vohra, Alan G Fowler, Manuel GaliñanesDepartment of Integrative Cardiovascular Physiology and Cardiac Surgery, University of Leicester, UK.Background The role of mitoKATP

channels, protein kinase C (PKC) and mitogen activated protein kinase (p38MAPK) on apoptosis in the context of myocardial preconditioning is unknown in humans.Objectives We investigated the cardioprotective mechanisms of preconditioning with ischaemia (IPC) and with cardioplegia (CPC) in the human myocardium. Material and Methods Right atrial appendages were obtained from patients at the time of coronary artery surgery. Free-hand tissue sections (n=8/group) were subjected to the following protocols: aerobic perfusion; 90min simulated ischaemia (SI) followed by 120min reoxygenation (R) in Krebs Henseleit HEPES solution (SI/R); IPC (5 min SI 5min R) and CPC (with St Thomas’ cardioplegia solution No.2 for 5min followed by 5min washout), prior to SI. Inhibitors of mitoKATP

channels, PKC and p38MAPK (1mM 5-hydroxydecanoate, 10µM chelerythrine and 10µM SB203580, respectively) were added for 10 min at the end of the equilibration period and before the induction of ischaemia in the latter three

groups. Cell damage was measured by creatine kinase (CK) endpoint assay. Cell apoptosis and necrosis were visualized in tissue sections with fluorescent dyes using FITC (TUNEL assay) and Propidium Iodide, respectively. Quantification was done by laser fluorescence confocal microscopy and NIH-Image software. Results CK leakage (IU/gram wet weight) was significantly reduced to a similar extent by IPC and CPC from 3.992±0.2895 to 2.475±0.186 and 2.567±0.25, respectively (p<0.05). Both IPC and CPC equally reduced necrosis from 12.663±1.579% in controls to 7.945±0.9377% and 7.877±1.801%, respectively (p<0.05). IPC also decreased apoptosis from 29.51±2.854% to 14.22±3.046% (p<0.05) and this was further reduced by CPC to 7.221±2.1% (p<0.05 versus IPC). The addition of 5-hydroxydecanoate, chelerythrine and SB203580 to both IPC and CPC resulted in an increase in necrosis whereas only 5-hydroxydecanoate and chelerythrine lead to a loss of the anti-apoptotic effect of IPC and CPC.

Conclusion CPC is more efficacious than IPC in reducing apoptosis. MitoKATP

channels, PKC and p38MAPK are involved in the inhibition of necrosis as a result of both IPC and CPC, whereas their anti-apoptotic effect may be mediated by mitoKATP channels and PKC only.

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7. ON-PUMP BEATING HEART MITRAL VALVE SURGERY FOR PATIENTS WITH POOR LEFT VENTRICULAR FUNCTIONS GHOSH, C Alexiou, R S Jutley & S K NaiDept of Cardiothoracic Surgery, Nottingham City Hospital, Nottingham, UKIntroduction Mitral valve surgery in the presence of poor left ventricular function is associated with higher mortality. We describe one surgeon’s (SKN) evolving practice of mitral valve surgery on the beating heart using normothermic cardiopulmonary bypass in this cohort of patients.

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Methods Between January 2000 and December 2002, 23 patients (13 women, 10 men), age range 54-81 years (mean (SD) 68.6(4.8) years) with mitral regurgitation and left ventricular ejection fraction <30% undergoing isolated repair (n=4) or replacement (n=19) were investigated. All patients received maximal drug therapy. 17 patients were New York Heart Association (NYHA) class III and 6 were class IV. The mean duration of follow-up was 17 ± 14 months and was complete for all survivors.Results The visual field of the on-pump beating heart was equal to that of conventional valvular operation, and technical accuracy was not compromised. The mean duration of ICU and hospital stay was 2.4 ± 1.3 days and 8.9 ± 2.6 days respectively. Mean bypass time was 74.35 ± 14.8 min. 30-day mortality was significantly lower (8.7%) when compared to mean Euroscore predicted mortality for this high risk group of patients (16.9%, p<0.001). The medium term 1- and 2- year survival were 87% and 78% respectively. NYHA class improved from 3.6 ± 0.5 to 1.9 ± 0.7 at follow-up (p=0.037). Conclusions On-pump beating heart mitral valve surgery is a good surgical option in patients with poor left ventricular function, and has advantages because conditions for the heart are more physiological with a beating tonus than with cardioplegia.

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8. Acute Lung Injury in a novel double hit murine ischaemia/reperfusion model. Shrivastava V, Norman KE, Hellewell PG.Cardiovascular Research Group, University of Sheffield.Background: Acute Respiratory Distress Syndrome (ARDS) accounts for a significant proportion of mortality after successful ruptured abdominal aortic aneurysm (RAAA) repair when compared to elective repair of abdominal aortic aneurysms (AAA). We hypothesize that the combination of two successive ischaemia/ reperfusion events predisposes

these patients to developing an overwhelming inflammatory response. This can result in acute lung injury and to the subsequent development of ARDS. Objectives: To establish a murine model that involves two successive ischaemia/reperfusion insults similar to that in patients undergoing emergency repair of a ruptured abdominal aortic aneurysm.Materials and Methods: C57BL/6 mice were anaesthetized with an intra-peritoneal mixture of ketamine, atropine and xylazine according to weight. The trachea, carotid artery and jugular vein were cannulated to allow for invasive blood pressure monitoring, the withdrawal of blood and administration of drugs. Blood was withdrawn from the carotid cannula to produce a fall in blood pressure of 30-50% from the baseline. This shed blood was heparinized and re-transfused after 60 min of hypotension. Then a laparotomy was performed and the infra-renal abdominal aorta clamped to render the lower limbs ischaemic. This clamp was removed after 60min and 125I bovine serum albumin administered intravenously. The animal was allowed to reperfuse for a further 60min and then a blood sample was taken and bronchoalveolar lavage performed. This data was used to calculate a lung permeability index. We investigated four experimental groups: sham hypotension plus sham ischaemia, hypotension only, iscahaemia only, combined haemorrahge plus ischaemia group.Results: 6/6 (100%) of the sham group survived 180min compared to 5/6 (83%) in the hind limb ischaemia group and 4/6 (66%) in the hypotension only group. Only 6/13 (46%) in the combined haemorrhage plus hind limb ischaemia survived 180min. The control group (n=4) had a Lung Permeability Index (LPI) of 5.2 ± 2.2 compared to 14.2 ± 2.6 for the combined hypotension and hind limb ischaemia group (n=4).Conclusion: Mice exposed to a combined insult of hypotension plus ischaemia have a higher mortality rate and have a higher lung permeability index when compared to mice exposed to either of these events alone.

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9. Off Pump Coronary Surgery Improves Left Ventricular Function In Patients Undergoing Total Arterial Revascularization: A Randomised Trial Using Cardiovascular Magnetic Resonance Imaging and Biochemical MarkersUniversity of Oxford Clinical Magnetic Resonance Research CentreDepartment of Cardiovascular MedicineJohn Radcliffe Hospital, Oxford OX3 9DUBackground: There is biochemical evidence that off pump coronary artery bypass grafting (OPCABG) reduces myocardial injury when compared to the use of cardiopulmonary bypass (ONCABG) but the functional significance of this is uncertain. We hypothesized that OPCABG surgery would result in reduced post-operative reversible (stunning) and irreversible myocardial injury, as assessed by cardiovascular magnetic resonance imaging (CMR). Methods: In a single centre randomised trial, 30 patients undergoing multi-vessel total arterial revascularization were randomly assigned to OPCABG and 30 patients to ONCABG surgery. Patients underwent pre-operative and early (day 6) post-operative cine MRI for global left ventricular function assessment, and contrast enhanced CMR for assessment of irreversible myocardial injury. Serial (pre-op, 1, 6, 12, 24, 48, 120 hours post-op) cardiac Troponin I measurements were obtained and correlated with the CMR findings.Results: The two surgical groups were well matched in terms of pre-operative (age, cardiopulmonary risk factors, pre-operative medication use) and peri-operative (number of distal anastomoses, inotropic requirements) factors. The mean pre-operative cardiac index was similar in the two surgical groups (2.9 +/- 0.7 ONCABG; 2.9 +/- 0.8 OPCABG; p = 0.9). Post-operatively, the cardiac index was significantly higher in the OPCABG group (2.7 +/- 0.6 ONCABG; 3.2 +/- 0.8 OPCABG; p = 0.04). The mean pre-

operative ejection fraction was 62 % +/- 12 % in the ONCABG group and 62 % +/- 11 % in the OPCABG group (p = 0.9). Post-operatively this decreased to 59 % +/- 11 % in the ONCABG group and increased to 65 % +/- 12 % in the OPCABG group (p = 0.03 for the change in EF). New irreversible myocardial injury was similar in incidence (36 % of ONCABG; 44 % of OPCABG; p = 0.8) and magnitude (6.3g +/- 3.6g ONCABG; 6.8g +/- 4.0g OPCABG; p = 0.9) across the two groups. The median areas under the curve (AUC) values for Troponin I release were significantly larger in the ONCABG group (182.0 µg/L) compared with the OPCABG group (135.0 µg/L; p=0.02).There was only a moderate correlation between the Troponin I AUC values and mean mass of new myocardial hyperenhancement (r2=0.4; p=0.008).Conclusion: In patients undergoing isolated coronary artery grafting, OPCABG surgery results in significantly better left ventricular function early after surgery, but does not reduce the incidence and extent of surgery-related irreversible myocardial injury.

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10. BEATING HEART TECHNIQUES APPLIED TO COMBINED VALVE AND GRAFT OPERATIONS REDUCES MYOCARDIAL DAMAGEM Poullis, M Shackcloth, W Dihmis, M Pullan, B FabriThe Cardiothoracic Centre, Liverpool Objectives: Myocardial damage secondary to prolonged cross clamp time is associated with significant morbidity and mortality. Combined valve and graft cases have longer cross clamp times secondary to procedure complexity. The larger the number of grafts the longer the cross-clamp time. Performing the grafts on a beating heart with cardioplegic arrest for performing the valve replacement/repair is a way of reducing cross clamp time and may result in less myocardial damage. Methods: 1011 consecutive patients having either isolated valve or valve and graft operations were studied. Group A,

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Table 1.MVRAVRNo of graftsGrp A(N=662)Grp B(N=41)Grp A(N=254)Grp

B(N=54)043343226148353944283394838367285840

Table 1: Number and proportion of gaseous and solid microemboli detected in three patient groups.

ProcedureHITSTotalMedian [IQR]Gaseous (%)Solid

(%)OPCABG 40 [28-80]*88%12%**ONCABG 275 [199-472]*72%28%**Open-heart Procedures860 [393-1321]*78%22%**

* Comparison of the total number of microemboli between the 3 groups: P<0.01** Comparison of the proportion of gas and solid microemboli in the 3 groups:

P<0.05

N=916 had cardoplegic arrest for all valve and bottom end anastomosis, group B, N=95 had the bottom ends performed on a beating heart. Myocardial damage was assessed by measuring CKMB at 16 hours post operatively. Patients were stratified by valve (mitral or aortic), and number of grafts. Results: An increase in aortic cross clamp time was associated with a significant increased CKMB release, p<0.001. Increased CKMB release resulted in increased ITU stay, p<0.001, increased hospital stay, p<0.001, and an increase in hospital mortality, p<0.001. Performing grafts off pump prior to performing valve replacement resulted in a significantly reduced cross clamp time, p<0.001, and myocardial damage as assessed by CKMB release, p<0.001 (See table 1)

Conclusions: Performing the grafts on a beating heart followed by cross-clamping the aorta to perform the valve replacement/repair, reduces cross-clamp time, resulting in significantly less myocardial damage. This in turn leads to a shorter ITU and hospital stay, and a lower in-hospital mortality.

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11. Solid and Gaseous Cerebral Microembolisation During Off-pump, On-pump and Open Cardiac SurgeryYasir Abu-Omar, Lognathen Balacumaraswami, Paul M. Matthews, David W. Pigott, David P. TaggartDepartment of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford, UKBackground Neurocognitive dysfunction remains a concern following cardiac surgery using cardiopulmonary bypass (CPB). Overt injury, usually a stroke, occurs in 3% of coronary artery bypass grafting (CABG) patients, while injury leading to cognitive impairment, only evident on detailed neuropsychological testing, occurs in up to 80% of all patients soon after surgery and persists in a quarter of these at six months. Early postoperative cognitive impairment correlates with later progression of cognitive decline and

impaired quality of life. Cardiopulmonary bypass (CPB) can cause brain injury through several mechanisms, but intraoperative cerebral microembolisation is believed to be one of the most important aetiological factors. Objectives Using a new generation transcranial Doppler (TCD) ultrasound (multifrequency, multirange TCD, Embodop, DWL), which can reject artefacts online and automatically discriminate between solid and gaseous microemboli, we compared the number and nature of intraoperative microemboli in patients undergoing on-pump and off-pump cardiac surgical procedures.Methods Bilateral continuous TCD monitoring of the middle cerebral arteries was performed in 45 patients (15 having off-pump coronary artery bypass grafting (OPCABG), 15 on-pump coronary artery bypass grafting (ONCABG) and 15 open-heart procedures). All recordings were performed using a multirange, multifrequency system to allow both measurement of the number and discrimination of the nature of microemboli in the three different groups. Patients with symptomatic carotid disease were excluded.Results The median number (interquartile range) of microemboli in the OPCABG, ONCABG and open-heart groups were 40 (28-80), 275 (199-472) and 860 (393-1321) respectively (P<0.01) (table1). Twelve percent of microemboli in the OPCABG group were solid compared to 28% and 22% in the ONCABG and open-heart groups respectively. The proportion of particulate microemboli was significantly higher in the on-pump groups compared to OPCABG (P<0.05). In the on-pump groups, 24% of microemboli occurred during CPB, and 56% occurred during aortic manipulation (cannulation, decannulation, application and removal of cross-clamp and / or side-clamp) (figure1).Figure 1: Gaseous and solid

microembolisation during the course of procedures performed using CPB.

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Table 1: In-hospital outcomes adjusted for propensity scoreOff-pump (n=211)On-pump (n=211)Odds ratio (95% CI)p ValueIn-hospital mortality (%)4.95.00.98 (0.35 –

2.75)0.98Myocardial Infarction (%)2.52.60.96 (0.24 – 3.92)0.96Stroke (%)1.05.60.09 (0.02 – 0.50)0.005Atrial arrhythmia (%)29.124.41.39 (0.84 – 2.30)0.21Renal failure (%)6.79.60.59 (0.26 – 1.34)0.21Re-explore for

bleeding (%)2.82.81.03 (0.27 – 3.95)0.97Sternal wound infection (%)1.62.70.50 (0.11 – 2.33)0.38Gastrointestinal complications(%)1.02.50.28 (0.04 – 1.79)0.18Post-operative stay >7 days

(%)43.457.00.46 (0.29 – 0.74)0.001

Conclusions In summary, cerebral microembolisation remains a problem during cardiopulmonary bypass. This can be minimised by performing off-pump surgery with avoidance of aortic manipulation. The ability to reliably discriminate between solid and gaseous microemboli has an important potential role in targeting various prevention strategies to improve neurological outcome following cardiac operations, particularly de-airing following open procedures.

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12. Coronary Surgery in patients with peripheral vascular disease: effect of avoiding cardiopulmonary bypassS Karthik 1, G Musleh 2, AD Grayson 1, DJM Keenan 2, DM Pullan 1, WC Dihmis 1, R Hasan 2, BM Fabri 1

1 The Cardiothoracic Centre Liverpool, United Kingdom. 2 Manchester Royal Infirmary, United Kingdom

Background: Due to the improvement in outcomes following coronary artery bypass grafting (CABG) that have been achieved over the last two decades, a greater number of patients are being referred for CABG. Also, the patients undergoing CABG are more likely to be older with a higher surgical risk. One group of patients who have been shown to have a significantly higher risk of adverse events following CABG are patients with peripheral vascular diseases (PVD).

Objective: We aimed to quantify the effect of avoiding cardio-pulmonary bypass in patients with PVD undergoing CABG.Methods: Between April 1997 and March 2002, 3,771 consecutive patients underwent CABG performed by five surgeons. 422 (11.2%) had PVD and of these, 211 (50%) received off-pump surgery. We used multivariate logistic regression analysis to assess the effect of off-pump surgery on in-hospital mortality and morbidity, while adjusting for treatment selection bias. Treatment selection bias was controlled for by constructing a propensity score, which was the probability of receiving off-pump surgery and included core patient characteristics. The C statistic for this model was 0.8.Results: Off-pump patients were more likely to have preoperative renal dysfunction, previous gastrointestinal surgery and less extensive disease. The left internal mammary artery was used more in off-pump compared to on-pump cases (90.1% versus 82.9%; p=0.033). In the univariate analyses, off-pump patients were less likely to have a post-operative stroke (p=0.007), and had shorter post-operative hospital stays (p<0.001). However, the incidence of new atrial arrhythmia was higher (p=0.028). Results after adjusting for differences in case-mix (propensity score) are shown in the table below.Conclusions: Off-pump coronary surgery is safe in patients with peripheral vascular disease, with acceptable results. The incidence of post-operative stroke is substantially reduced when avoiding cardiopulmonary bypass in patients with PVD. Their in-hospital stay was also significantly shorter.

Table 1: Number and proportion of

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13. Does Off-Pump Coronary Grafting Reduce Morbidity and Mortality Following Redo Surgery? Arun Srinivasan, AY Oo, AD Grayson, BM FabriThe Cardiothoracic Centre-Liverpool, United Kingdom

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Re-OPCAB (n=34)Re-ONCAB (n=15)p ValueIn-hospital mortality0% (0)20.0% (3)0.007Stroke0%

(0)13.3% (2)0.029CK-MB levels0 (0 to 23)25 (0 to 34)0.225Acute renal failure0% (0)13.3%

(2)0.029Blood loss in ICU402 mls (315 to 540)600 mls (390 to 750)0.048Atrial fibrillation11.8% (4)33.3% (5)0.072Inotrope support2.9% (1)20.0% (3)0.044Mechanical ventilation4 hrs (2 to 6)6 hrs (4

to 15)0.036Post-operative stay6 days (5 to 8)8 days (7 to 10)0.009

Background: Redo coronary surgery (CABG) is associated with increased risk of adverse outcomes. We hypothesised that off-pump CABG may provide a potential benefit to redo patients. [25]Methods: Data was collected prospectively as part of routine clinical practice on 49 consecutive patients undergoing isolated redo coronary surgery performed by one surgeon between April 1997 and March 2002. Thirty-four patients received redo off-pump CABG (Re-OPCAB) compared to 15 patients who received redo on-pump CABG (Re-ONCAB). Patient records were linked to the National Strategic Tracing Service, which records all deaths in the community, to establish follow-up mortality. All analysis was performed retrospectively. [71]Results: There were no significant differences between Re-OPCAB and Re-ONCAB according to age, sex, ejection fraction, extent of disease, peripheral vascular disease, diabetes, renal dysfunction, respiratory disease and emergency surgery; variables suggested for risk adjustment by the American College of Cardiology/American Heart Association guidelines. Re-OPCAB patients had fewer grafts (median: 2 versus 4; p<0.001). Post-operative results are shown in the table below. Follow-up mortality was 5.9% (n=2) in Re-OPCAB compared to 40.0% (n=6) in Re-ONCAB (p=0.003). [75]Conclusions: This study suggests that following redo CABG, early and late mortality, as well as morbidity, can be reduced by avoiding cardiopulmonary bypass. [22]

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14. Ten year experience of adult repair of coarctation of the aortaE Black1, A Goyal1, S Chatterjee1, M Hamilton1, S Naik2, R Firmin1, M Hickey1

1 Department of Cardiac Surgery, Glenfield Hospital, Leicester2 Department of Cardiac Surgery, Nottingham City hospital, NottinghamBackground Adult presentation of coarctation of the aorta is rare. Severe

hypertension is a major cause of morbidity and mortality in these patients. For the surgeon, atherosclerotic vessels and well-established collaterals present a surgical challenge.Objectives We sought to review the South Trent ten-year experience.Materials & Methods A retrospective review of all primary adult coarctation repairs was performed.Results Six patients, mean ages 28.8±13 yr. were found. Mean preoperative systolic BP was 179±16mmHg. 3 patients had bicuspid aortic valves. Tube-graft bypasses were used in 5 patients. Anatomical repair was performed in the first 3 patients via a thoracotomy. Of these, one was by resection and end-to-end anastomosis, two by bypass graft. Operative strategy for the next case was changed in light of problems with collateral haemorrhage with the pervious cases and literature reviews. Extra-anatomical bypass using cardiopulmonary bypass was performed in the next 3 cases. 2 of these patients also underwent AVR, one in combination with a root replacement. Post-operative systolic BP was reduced to 130±18.7mmHg (p=0.002 cf. preop.) at discharge.Conclusions Correction of the coarctation significantly reduced systolic BP. Approach via a thoracotomy is suited for anatomical correction but doesn’t facilitate surgery for associated abnormalities. Extra-anatomical bypass allows the surgeon to avoid friable collateral arteries, spinal chord ischaemia, the recurrent laryngeal and phrenic nerves and the lymphatic vessels. Also any concurrent proximal pathology (aortic valve disease, aneurysm of the root, CABG) can be addressed at the same operation.

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15. The initial experience with the the

Shelhigh BioConduitTM No-ReactTM Valves – 46 patientsA. Sosnowski, M. Matuszewski, R. Janas, A. Szafranek. Glenfield Hospital, LeicesterBackground: Aortic root replacement is also performed in elderly patients or those

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PRIVATEEuroSCORE (median(IQR) 5 (2-14) Systolic PA pressure (mean ±stdev) 55.8±14.8mmHg Grade of preop. TR (median(IQR)) 3 (3-4) Grade of postop. TR (median(IQR)) 0 (0,1)* NYHA preop. (median(IQR)) 3 (3,4) NYHA postop. (median(IQR)) 1 (1,2)* *=p<0.001

who have contraindications for anticoagulation. Therefore, a reliable tissue composite graft is necessary.Objective: To evaluate the short-term results of Shelhigh BioConduit use for aortic root/ascending aorta replacement.Material and methods: Between August 1999 and December 2002, 46 patients underwent implantation of Shelhigh BioConduit. Mean age at surgery was 69 (34-83) years, mean Parsonnet score 18.7. The indications for the use of a composite graft consisted of: aortic root/ascending aortic aneurysm (39 cases), aortic dissection (4 cases), severe calcification of the aortic root (2 cases), infective endocarditis with aortic root involvement (2 cases). Apart from aortic root replacement, 33 patients underwent replacement of ascending aorta, and 2 patients also aortic arch replacement. Dacron tube graft was used in addition to BioConduit in 10 cases. 13 patients had associated procedures (CABG, MVR). There were 6 redo operations. 3 patients underwent emergency or salvage procedures. In 17 patients the distal anastomosis was performed using the open technique.

Mean valve size

(mm)

CPB time (min)

XC time(min)

Circ. arrest time (min)

30-day mortality

25 +/- 2.2 177 +/- 90

122 +/- 43

32 +/- 16 7 (15%)

Results: The early mortality was 15%, mostly due to acute heart failure; one patient died of uncontrollable bleeding due to acute dissection with re-entry in descending aorta. One patient had a stroke, and one a TIA. One patient had to be re-explored for bleeding. At early follow up 75% of survivors were NYHA I, 21% - NYHA II, 4% - NYHA III. The mean pressure gradients in early TTE were 5-15 mm Hg regardless of valve size (Fig. 1), with no or a trace of AR.

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16. Tricuspid Valve Repair for Moderate Tricuspid Regurgitation

E Black, G Doukas, A Szafranek, A Sosnowski, T Spyt Glenfield Hospital, Leicester, United KingdomBACKGROUND The need for surgical correction of moderate functional tricuspid regurgitation (TR) remains uncertain. Some correct the left-sided valvular lesions only. Furthermore, there are no clear guidelines in the literature regarding tricuspid assessment.OBJECTIVES It has been our policy to repair at least moderate TR. We sought to review the affect of this policy prior to more formal studies of correction of TR. MATERIALS & METHODS We reviewed all patients who underwent tricuspid valve repair in addition to other corrective surgery between June 1998 and September 2001. TR was graded 1 to 4 with trans-thoracic and or trans-oesophageal echo.RESULTS 77 patients, 48% (37) male with a median (IQR) age of 66 (58-84) were found. Repairs were with either Cosgrove-Edwards or St.Jude bands (median (IQR) size 34 (32-38) mm). Additional procedures were 12 CABG, 3 AVR, 36 MVR/r, 12 AVR+MVR and 15 MVr+CABG. Bypass time was 120±47.4mins and cross-clamp time was 69.2±35.4mins. 30 day mortality was 8% (5/60). These patients all had MVR/r, 2 had additional AVR. Mortality over a median follow up of 8 months (3-29) was 15% (9/60). 30-day mortality was significantly affected by age> 75(p=0.05) later mortality by male sex (p=0.03) and poor LV (p=0.01).CONCLUSIONS Correction of TR with an annuloplasty band in these severely diseased patients is readily achieved. We believe that it is now necessary to establish a randomised trial to determine if the best treatment for these patients. Better preoperative guidelines might aid patient selection and encourage correction of moderate TR.

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17. ADJUNCTIVE ULTRASOUND EXPOSURE (USE) ENHANCES GENE

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DELIVERY TO VASCULAR SMOOTH MUSCLE CELLS (VSMC) IN-VITRO, AND IN EX-VIVO AND IN-VIVO PORCINE SAPHENOUS VEIN (SV).Enoch Akowuah1, Caroline Gray1, Sheila Francis1, Thierry Bettinger2, Axel Brisken3, David Crossman1, Christopher Newman1. Cardiovascular Research Group, University Sheffield1, Bracco Research, Geneva2, PharmaSonics Inc, CA, USA3.Background: Viral gene delivery is efficient but progress to human studies is hampered by concerns over safety. Non-viral alternatives whilst safe are relatively less efficient. We assessed the hypothesis that USE could mediate transfection of reporter genes, and the therapeutic gene TIMP 3, in VSMCs, organ cultured SV, and in-vivo SVG using a new generation of echocontrast microbubble agents, BR14. We compared USE and viral transgene expression.Method: VSMC were transfected with Lac-Z, eGFP, luciferase (luc) or TIMP 3 plasmid ± 1MHz USE for 60s in the presence of BR14, or with the corresponding recombinant adenovirus at 300PFU/cell. Organ cultured SV was transfected with luc plasmid ± 100mmHg non-distending static pressure for 5 min ± subsequent USE; In in-vivo experiments, porcine SV was transfected by intraluminal instillation of luc or TIMP 3 plasmid ± USE with BR14 and implanted as an interposition graft to the carotid artery. Samples were analysed for reporter gene and TIMP 3 expression at 48h (VSMC in-vitro) or 72h (intact SV ex-vivo and in-vivo) by luminometry, X-gal staining or western blotting. Results: USE with BR14 enhanced luc expression in VSMC by 3000-fold compared to DNA alone (1.2±0.18x106 vs 0.4±0.05 x103 light units (LU)/mg cell protein; p<0.001, n=4); the number of Lac-Z positive cells was also markedly increased (4.7±0.9 vs 0.1±0.1%; p<0.01, n=3). Static pressure alone did not increase luc expression in intact SV compared with DNA alone (2.6±3 vs 2.3±4 x104 LU/g

tissue weight). In contrast, the enhanced luc expression after USE alone was further increased using static pressure followed by USE (from 44.7±14 to 147 ±36 x104 LU/g; p<0.05 for these comparisons, n=6). In-vivo gene expression after ex-vivo transfection of SV with plasmid followed by USE was enhanced by 20-fold relative to naked plasmid alone (6±1.5 vs 0.3±0.1 x103 LU/5mm of graft). In-vitro transgene expression of lac-z, eGFP and TIMP 3 after adenoviral transfection was significantly higher than after USE transfection.Conclusion: These data provide proof-of-concept of USE enhanced transgene expression in VSMCs and in-vivo SVG. Though expression levels are less than those observed after viral transfection, the data lends further support to the concept of USE assisted gene delivery.

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18. Novel use of a mouse model to assess in vivo duration of action of topical antispasmodic agents.Shafi Mussa1, Tash Prior2, Nick Alp3, Kathryn J. Wood2, David P. Taggart1, and Keith M. Channon3.1Department of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford.2Nuffield Department of Surgery, University of Oxford.3Department of Cardiovascular Medicine, University of Oxford.Background Radial artery conduits for coronary artery bypass grafting have a tendency to vasospasm and an early failure rate of up to 10%. Topical antispasmodics are widely used to prevent vasospasm. Extensive studies have been conducted to measure the duration of action of such agents using in vitro (organ bath) methods. However their duration of action in vivo is unknown.Objective We compared the duration of action of two topical antispasmodic agents

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using the mouse aortic interposition graft as an in vivo model.Methods 2mm abdominal aortic interposition grafts were performed in 36 male C57BL6 mice. Donor aortic segments were incubated for 15 minutes with either phenoxybenzamine (PB, 10?M), verapamil/nitroglycerin solution (VG, 30?M each) or buffer (Control) immediately prior to grafting. The animals were recovered and then sacrificed at 2, 6, 12 and 24 hours after surgery (n=3 animals at each time point) to enable the grafts to be harvested for evaluation in organ bath studies. Segments studied at 0 hours remained ungrafted. Contraction to 60mM KCl and cumulative dose responses to phenylephrine (PE, 1nM-10?M) were measured in each segment.Results The figure shows responses to 10?M PE relative to KCl contraction in individual segments at each time point. Data are mean ± S.E.M. Responses to PE were abolished up to 16 hours post-operatively in PB pre-treated grafts. In contrast, the effects of VG were lost within only 2 hours. Asterisks indicate significant difference (p<0.05) from controls, by a two tailed unpaired students t-test.Conclusions Phenoxybenzamine pre-treatment of vascular grafts causes reduced ?-adrenergic vasoconstriction for up to 16 hours in vivo. Verapamil/nitroglycerin pre-treatment fails to prevent vasoconstriction in vascular grafts even 2 hours after resumption of blood flow. The mouse aortic interposition graft model is a useful technique to assess in vivo duration of action of established and novel topical antispasmodics. Measurement of duration of action of antispasmodic agents using exclusively in vitro methods should be interpreted with caution.

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19. Stenotic Disease Of The Left Main Stem Is Associated With Reduced Elasticity Of Extra-Cardiac Vessels Kotidis K, Hadjinikolaou L, Galinanes M

Department of Integrative Cardiovascular Physiology and Cardiac Surgery, University of LeicesterAIMS: To investigate whether the elastic properties of medium size extracardiac arteries are related with the distribution of coronary artery disease.METHODS: the internal thoracic arteries (ITA, n=53), long saphenous veins (LSV, n=38) and radial arteries (RA, n=35) from 74 patients undergoing coronary surgery were used in organ baths to determine their compliance, distensibility and incremental elastic modulus (iEmod). Twenty-four patients had left main stem (LMS) disease and 50 non-LMS coronary disease.RESULTS: the ITA from patients with LMS presented significantly lower compliance (-17%) and distensibility (-18%) and significantly higher iEmod (19%) at 80 mmHg than ITA from patients with non-LMS disease. RA from patients with LMS presented higher iEmod (50%) at 40 mmHg than RA from patients with non-LMS disease. Furthermore, LSV from patients with LMS had reduced compliance (-45%), reduced distensibility (-40%) and increased iEmod (34%) at 40 mmHg compared to those with non-LMS disease.

CONCLUSIONS: LMS coronary disease is associated with significantly reduced elasticity of extracardiac arteries and veins compared to non-LMS coronary disease. This finding suggests that widespread vascular elasticity defects may play a role in the development of LMS disease and be responsible for the higher incidence of graft failure and cardiac deaths observed in this condition.

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Table 1

VariablesHigh volume (n=133)Low volume (n=167)p valueEarly Mortality (elective)4(5%)6(8%)0.1Early Mortality (emergency)8(15%)16(14%)0.7Arch replacement21(16%)12 (7%)0.01Stroke6 (4%)9 (5%)0.3Renal failure4(3%)15 (10%)0.01Respiratory failure20(15%)37 (22%)0.1Re-op for bleeding12(9%)14 (8%)0.8Post op length of stay (days)14.8±11.413.2±10.90.3

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20. Use of Potassium Channel Openers To Prevent Spasm In The Radial Artery1Michael J Shackcloth, 1,2Alan R Conant , 2Alec WM Simpson, and 1Whalid C Dihmis 1The Cardiothoracic Centre, Liverpool NHS Trust, Thomas Drive, Liverpool, L14 3PE, UK 2Dept of Human Anatomy and Cell Biology, University of Liverpool, L69 3GE UK.Objectives: With the increased usage of the radial artery (RA) in coronary artery bypass graft surgery, the prevention of arterial spasm has become an important priority for surgeons. The potassium channel opener nicorandil has been shown to relax the radial artery in vitro. Nicorandil also stimulate nitric oxide production, which may be the mechanism of action by which it relaxes the radial artery. We investigated the effect of the reversible potassium channel opener pinacidil and the irreversible potassium channel opener minoxidil on radial artery segments.Methods: Sections of RA excess to surgical need were obtained from theatre, with fully informed patient consent. In vitro, using an organ bath, segments of RA were contracted with KCl at 90mM and 30mM and 10nM endothelin-1 or 100nM angiotensin II. The ability of minoxidil sulphate to either prevent contraction or relax sections of precontracted RA was tested. The presence of functional potassium channels was confirmed by pinacidil-induced relaxation, which was reversed by the potassium channel blocker, glibenclamide.Results In RA precontracted with 30mM KCl (p<0.05) and 10nM endothelin 1 (p<0.05), pinacidil caused a significant decrease in tension when compared with controls. Pinacidil failed to reverse contraction induced by 90mM KCl. The observed pinacidil-induced relaxation was fully reversed by glibenclamide, demonstrating the presence of functional potassium channels. Minoxidil however, failed to either reverse established contractions or significantly inhibit contractions to any of the agonists used.

Conclusions The reversible potassium channel opener pinacidil causes relaxation of the RA in vitro, demonstrating the presence of functional potassium channels. However, the irreversible potassium channel opener minoxidil failed to have any measureable effect. Whilst vasodilatation has been recorded in humans the lack of effect in RA may be due to the expression of a potassium channel subtype insensitive to minoxidil.

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21. Early outcome of surgery of the Ascending Aorta/Arch: Is there a relationship with caseload?P Narayan, M Caputo, B Mahesh, H Alwair, GD Angelini, AJ Bryan.Bristol Royal InfirmaryBACKGROUND: The relationship between caseload and early outcome remains a subject for debate in cardiac surgery in general. Surgery of the thoracic aorta is an area of specialist expertise within the adult cardiac surgical field. There is however, a conflict between concentrating expertise and the provision of effective emergency cover. This study examines the application of one organisational strategy over a ten year period in a single centre.OBJECTIVE: This study evaluates the early outcome of patients undergoing surgery of the ascending aorta/ aortic arch in a single institution and compares the results of a single high volume surgeon with low volume operators.MATERIALS AND METHODS: From 1993 till March 2003, 300 patients (aged 17 to 80, median 62) underwent operations for replacement of the ascending aorta/Arch. One hundred and fifteen (38%) patients underwent composite aortic root replacement, Thirty- two (10%) had aortic valve replacement with supracoronary interposition graft, and one hundred and twenty nine (43%) underwent replacement of the ascending aorta only. Thirty- three (11%) patients underwent aortic arch replacement with or without replacement of ascending or descending aorta. Emergency operation for aortic dissection

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OutcomeTotalPercentageResolved3356%Re-triggered1322%ITU/HDU814%Theatre12%Other46%

Trigger TypeTotal (% of triggers)Systolic Blood Pressure <90mmHg4855%Respiratory Rate <8 or >30 pm00%Oliguria<30mls/hr1315%Pulse <40 or >130 bpm910%Oxygen Saturation <90%1720%

was performed in one hundred and eight (36%) patients. RESULTS: The overall early mortality was 11%(34). Comparison of the results between the high volume (133 patients) and low volume surgeons (n=6, range 6 to 56 patients) are shown in Table1. The patient profile in both the groups were similar, however, a significantly higher number of aortic arch replacements were performed by the high volume operator. Apart from post-operative renal failure no other significant differences between the two groups were observed.CONCLUSION: Elective surgery of the ascending aorta/arch was associated with low mortality. Only limited differences were identified both with respect to the case profile and early clinical outcomes. These data suggest, that appropriate techniques disseminated within a group of surgeons, is an effective and practical method of service provision.

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22. An Early Warning Indicator System Improves Patient Outcome After Adult Cardiac SurgeryMartin Kinsella, Sarah Banks, Rachel Cooper, Graham CooperDepartment of Cardiothoracic Surgery Sheffield Teaching Hospitals NHS TrustBackground Early identification and appropriate treatment of ill patients improves their outcomes. We introduced an ‘Early Warning Indicator System’ (EWIS) to an adult cardiac surgical ward (C2) on 4/01/02. EWIS sets a series of physiological parameters. Any patient whose parameters fall outside pre-determined values ‘trigger’. Once a patient has triggered there is an escalation of medical input until the parameter returns to the pre-determined range. A report card is completed for each patient who triggers. Objectives To assess how EWIS functioned and whether or not it improved patient outcomeMaterial and Methods The report cards and clinical notes of all patients who triggered in the period 1/4/02 to 31/7/02 were reviewed and analysed.

Intensive Care Unit records, Progressive Care Unit records and Hospital Episode Statistics were reviewed to determine the number of admissions to C2, the number of deaths on the ward and number of returns to Intensive Care Unit (ITU) for the period 1/3/01 to 31/8/01 (prior to introduction of EWIS) and 1/3/02 to 31/8/02. The combined end-points of death on the ward and readmission to ITU were compared by chi-squared test.Results In the 5 months from 1/4/02, 59 patients caused 87 triggers. Thirteen patients (22%) triggered more than once. The cause of the triggers are shown in the table:

The outcomes of these patients were:There was a significant reduction in death on the ward and readmission to ITU between 1/3/01 to 31/8/01 and 1/3/02 to 31/8/02; 32 of 458 admissions (6.98%) compared to 18 of 584 admissions (3.08%) (p<0.001).Conclusions EWIS is applicable to adult cardiac surgical practice. The majority of triggers are for haemodynamic parameters and almost ¼ of patients trigger more than one parameter or more than one time. We observed a significant reduction in death and return to ITU following introduction of EWIS.

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23. Tracheal stenosis: A comparison of stenosis caused by surgical tracheostomy and percutaneous tracheostomyG Raghuraman*, D Mullhi *, F Gao *J Marzouk#,*Department of Anaesthesia & Intensive Care Medicine, #Department of Thoracic Surgery, Birmingham Heartlands Hospital, Birmingham, B5 9SS, UKBackground: Tracheal stenosis following tracheostomy is considered as the most crucial long-term complications in recent literature. (1) Although CT scan, MRI, pulmonary function tests, endoscopy have all been used to diagnose this condition, surgical findings are likely to be more accurate and hence more reliable.

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Table 1. 70 (106)PCT (n=15)SgT (n=14)Age (years)42 (33-51)49 (37-59)Gender (M/F)8/76/8Duration of IPPV (day)20 (15-

33)24 (12-28)Onset of stenosis (Weeks) Mean5.7 (1.9)*

p-0.005 PCT vs. .SgT70 (106)Distance below the vocal cords (cm) M (95% CI)1.6 * (1.1-2.1)p-0.002 PCT vs. SgT3.4 (2.3-4.5)Length of stenosis (cm)M (95% CI)3.0 (2.5-3.4) 2.7 (2.2-3.1)Diameter of stenosis (mm) M (95% CI)4.3 (2.0-6.6)4.7 (3.4-6.0)Tracho-oesphageal fistula2 casesNoneSurgeons’ commentsSurgery more difficultSurgery easier

However there has been no studies comparing the surgical findings of stenosis caused by percutaneous tracheostomy with surgical tracheostomy. Objective: Compare the surgical findings of tracheal stenosis caused by surgical tracheostomy and percutaneous tracheostomy.Materials and Methods: This was a retrospective and prospective case notes review study done on 29 patients referred for surgical treatment of tracheal stenosis in periods between 1993 and 2003. Patients were divided into two groups: percutaneous tracheostomy (PCT) and Surgical Tracheostomy (SgT). Location, length, diameter, time of onset of stenosis and other tracheal injuries as well as possible precipitating factors in each group were reported Results: The results are shown in table 1.Onset of stenosis was much quicker in the percutaneous group [5.7 weeks Mean (1.9)] compared to the surgical group [70 weeks Mean(106)]. Also in the percutaneous group the upper level of stenosis was closer to the vocal cords (1.6 cm CI 95%-1.1-2.1) compared to the surgical group (3.4 cms CI-2.3-4.5). In the percutaneous group there were two cases of tracheo-oesophageal fistula while there were none in the surgical group.Conclusion: Tracheal stenosis caused by percutaneous tracheostomy was subglottic in nature and was difficult to correct.

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24. Conservative Management Of Estrogenic Oesophageal PerforationsS. Hasan, ANA Jilaihawi, D PrakashHairmyres Hospital East Kilbride Glasgow.Background: Oesophageal Perforations carry a high mortality and morbidity. There is.no consensus as to the best form of management for this condition. Objective: We reviewed all patients of Iatrogenic Perforations seen at our centre to assess the result of conservative management Material and Method: We retrospectively reviewed all 26 patients with Iatrogenic Oesophageal Perforations seen at our

centre over the last ten years, who were all managed conservatively. The mean age of the group was 59 years (16-92yrs). Fourteen out of them were females. Twenty-two (85%) were seen within 6 hours of perforation. Seventeen patients had non-malignant pathology while nine had oesophageal carcinoma. The vast majority of them(89%) resulted from oesophageal dilatations. Chest pain was the commonest symptom that was present in 85% of the cases. All patients were managed conservatively on a regimen comprising keeping them nil by mouth on intravenous fluids and broad spectrum antibiotics. Eight patients were kept  on TPN while six required chest drains, 5 for pneumothoraces and 1 for pleural collection. Results: Twenty-two (85%) of the 26 patients survived on this regimen and their perforations healed. One patient required an early operation for uncontrolled sepsis while 5 patients had oesophageal resections, 4 for carcinomas and one for a congenital short oesophagus after their perforations had healed. The overall morbidity was low and these results were comparable to those of operative treatment in published series. Early diagnosis is crucial for the success of this regimen and this is only possible if a high index of suspicion is maintained. Conclusions: We conclude that conservative management is the preferred treatment for clean Iatrogenic Perforation of the oesophagus.

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