Publications

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    ABSTRACT: Because of the extensive involvement of the aorta, surgical treatment of its chronic dissection continues to represent a surgical challenge. We conducted a study of a multicenter experience to describe a multicenter experience in the treatment of this complex pathology, using the frozen elephant trunk (FET) technique. Between January 2005 and May 2010, 240 patients underwent treatment with the FET technique and had their clinical data collected in the International E-vita Open Registry. Ninety of the patients, who were the population in the present study, underwent operations for chronic dissection of the aorta (type A, 77%). The mean age of these 90 patients was 57 ± 12 years, and 72 (80%) of the patients were male. Sixty-two patients (69%) had undergone a previous aortic operation. All of the procedures in the study were performed with the aid of antegrade selective cerebral perfusion. Total replacement of the aortic arch was done in 84 patients (93%). Cardiopulmonary bypass, myocardial ischemia, cerebral perfusion, and visceral ischemia times were 243 ± 65, 145 ± 48, 86 ± 24, and 75 ± 22 minutes, respectively. In-hospital mortality was 12% (11 patients). One patient died from a stroke and 8 patients (9%) died from ischemic spinal cord injury. The false lumen (FL) in the patients' aortae was evaluated with computed tomography after operation and during follow up. The rates of complete thrombosis of the FL around the elephant trunk were 69% and 79% at the first and last postoperative examinations, respectively. The rates of 4-year survival and freedom from aortic reoperation were 78% ± 5% and 96% ± 3%, respectively. The treatment of chronic aortic dissection (AD) with the FET technique is feasible, with respectable results. The rate of aortic reoperation with the use of this technique appears to be lower than that with a conventional approach to the repair of chronic AD. Ischemic spinal cord injury represents a concerning complication of the FET technique but seems to be unrelated to thrombosis of the FL.
    The Annals of thoracic surgery 11/2011; 92(5):1663-70; discussion 1670. · 3.45 Impact Factor
  • Robert Stuart Bonser
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 07/2011; 40(5):1077. · 2.40 Impact Factor
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    Robert Stuart Bonser
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 06/2011; 41(1):191-2. · 2.40 Impact Factor
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    ABSTRACT: A 45-year-old male heart-lung transplant recipient reported reduced exercise tolerance two months post-transplant. Spirometry, right heart pressures, bronchoscopy, trans-bronchial and endomyocardial biopsy were normal. Investigations demonstrated posterior and leftwards herniation of the heart through the posterior pericardial window created during the transplant operation with secondary 90 degrees forward twist of the left lung. This phenomenon generated mild functional narrowing of the left pulmonary artery demonstrable on magnetic resonance imaging. Cardiac herniation with lung torsion is a rare finding post heart-lung transplantation and usually manifests in the early postoperative period with haemodynamic compromise, requiring immediate correction. Our case demonstrates that heart graft herniation and secondary partial lung torsion can occur in the chronic phase without catastrophic consequences.
    Interactive Cardiovascular and Thoracic Surgery 03/2010; 10(6):1044-6. · 1.11 Impact Factor
  • Jegatheesan Saravana Ganesh, Robert S Bonser
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    ABSTRACT: The optimal myocardial protection method for aortic valve replacement in the setting of prior coronary artery bypass surgery remains a subject of debate. Protection is particularly challenging when a patent pedicled internal thoracic artery graft supplies a proximally obstructed left anterior descending artery. Herein, we describe a modification of an old technique; continuous coronary perfusion, which can be used in selected, anatomically suitable cases.
    Interactive Cardiovascular and Thoracic Surgery 12/2009; 10(3):437-8. · 1.11 Impact Factor
  • Aaron Matthew Ranasinghe, Robert Stuart Bonser
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 09/2009; 36(6):943-5. · 2.40 Impact Factor
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    ABSTRACT: Cardiac troponin-I (cTnI) levels in the potential heart transplant donor may be a marker of heart dysfunction and predictive of recipient outcome. We studied the prevalence of cTnI elevation, its association with heart function and usability and its relationship with the time duration from coning. In a prospective study, cTnI measurement, Swan-Ganz catheterisation and transthoracic echocardiography were performed at initial assessment in 79 potential heart donors (mean age 43 +/- 13.1 years). All donors were then managed according to a strict algorithm to optimise cardiac function, some receiving hormonal therapy as part of a randomised trial. Donor heart suitability for transplantation was assessed after 7 h of management. The association of cTnI with initial functional indices was assessed and outcome compared for donors categorised according to cTnI level < or = 1 microg l(-1) or >1 microg l(-1). Serum cTnI levels negatively correlated with initial cardiac index (CI) (p = 0.003), right (p < 0.001) and left ventricular ejection fraction (p = 0.001) and positively with LV Tei index (p = 0.003). Serum cTnI was >1 microg l(-1) in 29/79 donors. Higher CVP (10 +/- 5.1 vs 7.9 +/- 2.9; p = 0.026) and PAWP (12 +/- 5.4 vs 8.1 +/- 3.1; p = 0.002), lower cardiac index (2.7 +/- 1.1 vs 3.6 +/- 0.9; p = 0.001) and fractional shortening (p < 0.01) and worse wall motion score index (p < 0.01) were observed in the cTnI >1 microg l(-1) group. CTnI and functional markers correlated with the time duration from coning. The donor cTnI level represents a biochemical surrogate of functional donor heart assessment. High cTnI is associated with worse donor heart function and may act as a prompt for detailed assessment and optimisation.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 04/2009; 36(2):286-92; discussion 292. · 2.40 Impact Factor
  • Nicholas R Banner, Chris A Rogers, Robert S Bonser
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    ABSTRACT: In the absence of randomized trials comparing heart transplantation (HTx) with medical therapy for the treatment of advanced heart failure (HF), the role of HTx remains uncertain. Using data from a national audit, we examined the effect of HTx on HF mortality in the United Kingdom. Two thousand two hundred nineteen adults listed for HTx from April 1995 to October 2003 and followed to June 2007 were analyzed. In a substudy of 627 patients from two centers, ambulatory patients were risk-stratified by the heart failure survival score. A time-dependent nonproportional hazards model was used to estimate the effect of HTx. Fourteen percent of patients were nonambulatory at listing. Death while waiting was higher among nonambulatory patients (19% vs. 14% in the ambulatory group, P<0.001 with 76% vs. 71% being transplanted). Posttransplant survival to 3 years was 78% and 75% in nonambulatory and ambulatory groups, respectively (P=0.68). HTx was found to benefit all groups. For nonambulatory patients, the risk of dying after HTx fell below the risk of dying while waiting after 10 days (95% CI 2-18) with a net survival benefit after 26 days (95% CI 5-53); for the ambulatory group the estimates were 42 days (95% CI 36-47) and 274 days (95% CI 214-359), respectively. In the substudy cohort net survival benefit was seen after 20, 124, 291, and 729 days for the nonambulatory, high, moderate, and low heart failure survival score risk groups, respectively. HTx remains an effective treatment of advanced HF. Prioritization of patients with refractory HF is rational, because they are the first to benefit.
    Transplantation 12/2008; 86(11):1515-22. · 3.78 Impact Factor
  • Deborah K Harrington, Fernanda Fragomeni, Robert Stuart Bonser
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    ABSTRACT: Aortic arch surgery necessitates interrupted brain perfusion and carries a risk of brain injury. Various brain protective techniques have been advocated to reduce risk including hypothermic arrest and retrograde or selective antegrade perfusion. Knowledge of the pathophysiologic consequences of deep hypothermia, may aid the surgeon in deciding when to initiate circulatory arrest and for how long. Retrograde cerebral perfusion use was advocated to prolong safe arrest durations but may not improve outcomes. Selective antegrade cerebral perfusion appears to have become the preferred method of brain protection. However, the delivery conditions and optimal perfusate constitution require further study.
    The Annals of thoracic surgery 03/2007; 83(2):S799-804; discussion S824-31. · 3.45 Impact Factor
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    ABSTRACT: Heart transplantation activity is steadily declining worldwide, despite initiatives to increase the donor pool. The yield of transplantable hearts remains low, leading to wastage of over two-thirds of donor organs. Accurate assessment and intervention is required to increase the number of transplantable hearts. The retrieval rate could be increased if techniques become available to differentiate between transplantable and nontransplantable hearts. Echocardiography is an ideally suited noninvasive investigation that may guide donor optimization. However, there are technical difficulties in acquiring high-quality views, and changes in ventricular function following catecholamine storm in brainstem death often lead to misinterpretation of standard 2D images. Current advances in technology, including the routine use of left ventricular contrast, 3D imaging and tissue doppler studies, may improve the accuracy, and thereby the utilization, of echocardiography in donor heart assessment.
    Future Cardiology 01/2007; 3(1):99-104.
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    ABSTRACT: Abstract Introduction Inflammation contributes to cardiovascular disease and is exacerbated with increased adiposity, particularly omental adiposity; however, the role of epicardial fat is poorly understood. Methods For these studies the expression of inflammatory markers was assessed in epicardial fat biopsies from coronary artery bypass grafting (CABG) patients using quantitative RT-PCR. Further, the effects of chronic medications, including statins, as well as peri-operative glucose, insulin and potassium infusion, on gene expression were also assessed. Circulating resistin, CRP, adiponectin and leptin levels were determined to assess inflammation. Results The expression of adiponectin, resistin and other adipocytokine mRNAs were comparable to that in omental fat. Epicardial CD45 expression was significantly higher than control depots (p < 0.01) indicating significant infiltration of macrophages. Statin treated patients showed significantly lower epicardial expression of IL-6 mRNA, in comparison with the control abdominal depots (p < 0.001). The serum profile of CABG patients showed significantly higher levels of both CRP (control: 1.28 ± 1.57 μg/mL vs CABG: 9.11 ± 15.7 μg/mL; p < 0.001) and resistin (control: 10.53 ± 0.81 ng/mL vs CABG: 16.8 ± 1.69 ng/mL; p < 0.01) and significantly lower levels of adiponectin (control: 29.1 ± 14.8 μg/mL vs CABG: 11.9 ± 6.0 μg/mL; p < 0.05) when compared to BMI matched controls. Conclusion Epicardial and omental fat exhibit a broadly comparable pathogenic mRNA profile, this may arise in part from macrophage infiltration into the epicardial fat. This study highlights that chronic inflammation occurs locally as well as systemically potentially contributing further to the pathogenesis of coronary artery disease.
    Cardiovascular Diabetology 01/2006; · 4.21 Impact Factor
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    ABSTRACT: A 56-year-old man developed left heart failure secondary to left to right shunt due to acquired aorto-pulmonary artery (PA) fistula. He had previously undergone aortic root replacement for streptococcal aortic valve endocarditis. A modified strategy involving interventional radiology and surgical technique was employed to deal with this complex surgical challenge. A balloon catheter was placed in the right PA to enable fistula occlusion during cardiopulmonary bypass followed by repair using cardiopulmonary bypass and circulatory arrest.
    Interactive Cardiovascular and Thoracic Surgery 11/2005; 4(5):388-90. · 1.11 Impact Factor
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    ABSTRACT: The long-term (five-year) comparative results of treatment of multivessel coronary artery disease with stenting or coronary artery bypass grafting (CABG) is at present unknown. The Arterial Revascularization Therapies Study (ARTS) was designed to compare CABG and stenting in patients with multivessel disease. A total of 1,205 patients with the potential for equivalent revascularization were randomly assigned to CABG (n = 605) or stent implantation (n = 600). The primary clinical end point was freedom from major adverse cardiac and cerebrovascular events (MACCE) at one year; MACCE at five-year follow-up constituted the final secondary end point. At five years, there were 48 and 46 deaths in the stent and CABG groups, respectively (8.0% vs. 7.6%; p = 0.83; relative risk [RR], 1.05; 95% confidence interval [CI], 0.71 to 1.55). Among 208 diabetic patients, mortality was 13.4% in the stent group and 8.3% in the CABG group (p = 0.27; RR, 1.61; 95% CI, 0.71 to 3.63). Overall freedom from death, stroke, or myocardial infarction was not significantly different between groups (18.2% in the stent group vs. 14.9% in the surgical group; p = 0.14; RR, 1.22; 95% CI, 0.95 to 1.58). The incidence of repeat revascularization was significantly higher in the stent group (30.3%) than in the CABG group (8.8%; p < 0.001; RR, 3.46; 95% CI, 2.61 to 4.60). The composite event-free survival rate was 58.3% in the stent group and 78.2% in the CABG group (p < 0.0001; RR, 1.91; 95% CI, 1.60 to 2.28). At five years there was no difference in mortality between stenting and surgery for multivessel disease. Furthermore, the incidence of stroke or myocardial infarction was not significantly different between the two groups. However, overall MACCE was higher in the stent group, driven by the increased need for repeat revascularization.
    Journal of the American College of Cardiology 09/2005; 46(4):575-81. · 14.09 Impact Factor
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    ABSTRACT: To compare coronary stent implantation and bypass surgery for multivessel coronary disease in patients with renal insufficiency. In the ARTS trial, 142 moderate renal insufficient patients (Ccr<60 mL/min) with multivessel coronary disease were randomly assigned to stent implantation (n=69) or CABG (n=73). At 5 years, there was no significant difference between the two groups in terms of mortality (14.5% in the stent group vs. 12.3% in the CABG group, P=0.81), or combined endpoint of death, cerebrovascular accident (CVA), or myocardial infarction (MI) (30.4% in the stent group vs. 23.3% in the CABG group, P=0.35). Among patients who survived without CVA or MI, 18.8% in the stent group underwent a second revascularization procedure when compared with 8.2% in the surgery group (P=0.08). The event-free survival at 5 years was 50.7% in the stent group and 68.5% in the surgery group (P=0.04). At 5 years, the differences in mortality and combined incidence of death, CVA, and MI between coronary stenting and surgery did not reach statistically significant level. However, the occurrence of MACCE in the stent group was higher than in the CABG group, mainly driven by the higher incidence of repeat revascularization in the stent group.
    European Heart Journal 08/2005; 26(15):1488-93. · 14.10 Impact Factor
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    ABSTRACT: Our aim was to follow changes in myocardial function and physiology in patients awaiting coronary artery bypass surgery (CABG) and relate changes to post-revascularisation functional response. In 21 patients with CAD and LV dysfunction, myocardial glucose utilisation (MGU) and blood flow (MBF) were measured with positron emission tomography using F-18-fluorodeoxyglucose and oxygen-15-labelled water. Left ventricular function, MGU, and MBF were re-assessed after one year, immediately prior to CABG. At baseline, dysfunctional myocardium displayed a reduction in MGU, hyperaemic MBF, and coronary vasodilator reserve (CVR) compared to normally functioning muscle. In the year preceding CABG, the overall wall motion score index increased (2.09 +/- 0.65 vs. 2.3 +/- 0.7, p=0.0001) and the LV ejection fraction decreased (30.6 +/- 11.1% vs. 27.3 +/- 11.5%, p<0.001). LVEF fell in 14 patients (28.7 +/- 9.4 vs. 23.8, p<0.0001). Aggregate regional wall motion worsened in 15 patients. In contrast to myocardium displaying stable function at echocardiography, myocardium with evidence of deterioration showed a parallel decrease in hyperaemic MBF and CVR (1.57 +/- 0.67 vs. 1.19 +/- 0.7 ml/min/g, [p=0.004] and 1.9 +/- 0.75 vs. 1.33 +/- 0.6, [p=0.005], respectively). Such myocardium displayed attenuated recovery postoperatively (21/68 [31%] LV segments) versus 'waiting-time' stable myocardium (98/169 [58%], p=0.0002). Delayed revascularisation in ischaemic left ventricular impairment results in declining function and a reduced likelihood of contractile improvement.
    European Heart Journal 03/2004; 25(6):500-7. · 14.10 Impact Factor
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    ABSTRACT: Recent advances in medical therapy have improved outcomes for patients with severe heart failure. However, overall survival remains poor. Transplantation is an established therapy for these patients but is limited by the large mismatch between demand and donor organ availability. Recently it has been recognised that not all ventricular dysfunction secondary to coronary artery disease is irreversible. Revascularisation in certain patients would appear to improve ventricular function. These patients are said to demonstrate myocardial "hibernation". Revascularisation in these patients may provide a further treatment option in the treatment of heart failure.
    Heart Failure Reviews 05/2003; 8(2):175-9. · 4.45 Impact Factor
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    ABSTRACT: Life expectancy in patients with cystic fibrosis (CF) has recently improved due to numerous factors, including a multidisciplinary approach to their management. Prolonged survival may have led to an increasing impact of liver disease on the prognosis of CF patients. The aim of this study was to assess the role of liver transplantation in patients with CF. The factors influencing outcome in 24 patients (15 adults and nine children) with CF who have received single liver transplantation, triple heart-lung-liver transplantation (tx) or died while being assessed for triple grafting, were analyzed. Median age at tx in single liver recipients (13 years) was lower than in triple graft recipients (21 years) and those who died (23 years). All patients who received single liver tx made an excellent recovery, including significant improvement of their respiratory function (mean forced vital capacity (FVC) increased from 61% before transplantation to 82% of expected, 6-9 months after tx). Four out of five patients who received triple tx died (0-2 months) after operation. On the basis of our retrospective review, we propose modifications to an existing scoring system for liver tx assessment in CF by scoring additional points for elevated white blood count, bilirubin, and impaired pulmonary function. These changes will need to be evaluated prospectively to confirm their predictive value. Liver transplantation is effective therapy in young patients with cystic fibrosis, portal hypertension and hepatic dysfunction, and is indicated before a critical stage of deteriorating lung function is reached. In patients with both end-stage liver and lung disease, triple tx has a poor prognosis. Pre-emptive liver tx in younger patients with CF not only has a better outcome but improves lung function.
    Journal of Gastroenterology and Hepatology 03/2002; 17(2):208-13. · 3.33 Impact Factor

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