Category Archives: Research

Bilateral internal mammary arteries: evidence and technical considerations

Vallely MP, Edelman JJ, Wilson MK

Ann Cardiothorac Surg 2013 Jul;2(4):570-7

PMID: 23977638


Bilateral internal mammary artery (BIMA) grafts are used for coronary revascularisation by only a minority of surgeons, despite a growing body of evidence suggesting improved survival when compared to use of only one internal mammary artery with additional saphenous vein grafts. Herein we review the evidence supporting revascularisation with BIMA and suggest reasons why the majority of surgeons use only one internal mammary artery. We discuss technical considerations, various graft combinations and the use of BIMA to facilitate anaortic off-pump coronary artery bypass (OPCAB).

Anaortic off-pump coronary artery bypass grafting in the elderly and very elderly

Cooper EA, Edelman JJ, Black D, Brereton RJ, Ross DE, Bannon PG, Wilson MK, Vallely MP

Heart Lung Circ 2013 Dec;22(12):989-95

PMID: 23827207

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BACKGROUND: Elderly patients undergoing surgical revascularisation may disproportionately benefit from avoiding manipulation of the ascending aorta and cardiopulmonary bypass. In this multi-centre observational study, we sought to determine the 30-day outcomes of anaortic off-pump coronary artery bypass (OPCAB) in an elderly and very-elderly population.

METHODS: Data were prospectively collected for all patients aged >70 years old (y) undergoing anaortic OPCAB at three hospitals between January 2002 and October 2011. Analysis was carried out on two age sub-groups (70-79 y vs. ≥80 y). Multiple logistic regression was used to identify predictors of post-operative 30-day mortality.

RESULTS: In total, 1135 patients >70 years underwent anaortic OPCAB – 817 (72%) patients were aged 70-79 y while 318 (28%) were aged ≥80 y. The rate of mortality and morbidity for both groups was low: 30-day mortality (70-79 y: 1.8%; ≥80 y: 2.8%) or permanent stroke (70-79 y: 0.2%; ≥80 y: 0.9%). Chronic lung disease, a history of previous myocardial infarction and left main disease were independent predictors of 30-day mortality.

CONCLUSIONS: OPCAB is associated with low rates of 30-day mortality and peri-operative stroke in this elderly and very elderly patient cohort. Anaortic OPCAB can provide excellent short-term post-operative outcomes and may give the elderly and very elderly population the opportunity to benefit from surgical coronary revascularisation.

Outcomes of surgical aortic valve replacement in octogenarians

Harris RS, Yan TD, Black D, Bannon PG, Bayfield MS, Hendel PN, Wilson MK, Vallely MP

Heart Lung Circ 2013 Aug;22(8):618-26

PMID: 23422500


BACKGROUND: In the era of TAVI, there has been renewed interest in the outcomes of conventional AVR for high-risk patients. This study evaluates the short- and long-term outcomes of AVR in octogenarians.

METHODS: A retrospective review was performed of all 117 patients aged ≥ 80 years who underwent AVR, (isolated AVR (n = 60) or AVR+CABG (n = 57),) from August 2005 to February 2011 at Royal Prince Alfred Hospital and Strathfield Hospital. Univariate analysis was used to compare pre- and post-operative variables between younger and older subgroups (age 80-84, n = 82; age 85-89, n = 35 respectively). Long-term survival data was obtained from the National Death Index at the Australian Institute of Health and Welfare and survival curves were constructed using the Kaplan-Meier method.

RESULTS: The median age was 83 years (interquartile range, 81-85 years), 46.2% were females, the median EuroSCORE was 10.89% (interquartile range, 8.20-16.45%) and 16.2% of patients had a EuroSCORE ≥ 20%. The difference between subgroups for history of stroke was significant (p = .042). Post-operative complications included pleural effusion (12.8%), new renal failure (4.3%) and respiratory failure (4.3%). The rate of major adverse events was extremely low, with no cases of stroke. The 30-day mortality rate was 3.4%. There was a significant difference between subgroups for 30-day mortality (p = .007). 38.9% of patients were discharged home, 11.5% were transferred to another hospital and 38.9% spent a period of time in a rehabilitation institution post discharge. In terms of long-term survival, the six-month, one-year and three-year survival was 95.6%, 87.6% and 58.4% respectively.

CONCLUSIONS: Surgical AVR yields excellent short- and long-term outcomes for potentially high-risk, elderly patients.

Total percutaneous cardiopulmonary bypass with Perclose ProGlide

Ramponi F, Yan TD, Vallely MP, Wilson MK

Interact Cardiovasc Thorac Surg 2011 Jul;13(1):86-8

PMID: 21482577


Suture-mediated closure devices have been previously described as an interesting alternative to femoral cutdown during endovascular aortic procedures. The insertion of two or three devices before the cannulation (preclose technique) permits successful percutaneous access also with a large sheath up to 24 Fr diameter. The main benefit of percutaneous access is a lower rate of complication at the groin. The same technique can be applied to cardiac procedures where femoral cannulation for cardiopulmonary bypass (CPB) is required. We report a series of 12 patients in whom total percutaneous CPB was successfully established using a Perclose ProGlide for the arterial access.

Replacement of the aortic root with a composite valve-graft conduit: risk factor analysis in 246 consecutive patients

Woldendorp K, Starra E, Seco M, Hendel PN, Jeremy RW, Wilson MK, Vallely MP, Bannon PG

Heart Lung Circ 2014 Dec;23(12):1187-93

PMID: 25038031

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BACKGROUND: Composite valve-graft (CVG) replacement of the aortic root is a well-studied and recognised treatment for various aortic root conditions, including valvular disease with associated aortopathy. There have been few previous studies of the procedure in large numbers in an Australian setting.

METHOD: From January 2006 to June 2013, 246 successive patients underwent CVG root replacements at our institution. Mean age was 56.8 years, 85.4% were male, and 87 had evidence of bicuspid aortic valve. Indications for operation included ascending aortic aneurysm in 222 patients, annuloaortic ectasia in 67 patients, and aortic dissection in 38 patients.

RESULTS: The overall unit 30-day mortality was 5.7%, including: elective 30-day mortality of 2.2%, and emergent 30-day mortality of 17.2%. Statistically significant multivariate predictors of 30-day mortality were: acute aortic dissection (OR=20.07), peripheral vascular disease (OR=11.17), new ventricular tachycardia (OR=30.17), re-operation for bleeding (OR=14.42), concomitant mitral stenosis (OR=68.30), and cerebrovascular accident (OR=144.85).

CONCLUSIONS: Low postoperative mortality in our series matches closely with results from similar sized international studies, demonstrating that this procedure can be performed with low risk in centres with sufficient experience in the operative procedure.

The freestyle aortic bioprosthesis: a systematic review

Sherrah AG, Edelman JJ, Thomas SR, Brady PW, Wilson MK, Jeremy RW, Bannon PG, Vallely MP

Heart Lung Circ 2014 Dec;23(12):1110-7

PMID: 25047283

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BACKGROUND: The Medtronic Freestyle bioprosthesis (FSB) provides an alternative to other prostheses for both aortic valve and aortic root surgery. This paper is a systematic review of the post-operative outcomes in patients with aortic valve and/or aortic root disease following FSB implantation.

METHODS: Electronic databases were searched for primary analysis, prospective randomised studies comparing the FSB with an alternative aortic prosthesis were included. Additionally, case series that included data for at least 100 individual operated patients were used for secondary analysis.

RESULTS: Among three identified randomised studies, 199 FSB cases were compared with homografts, and stented and an alternative stentless bioprosthesis. The FSB showed comparable hospital mortality (4.5% vs. 5.3%) and eight-year actuarial survival (80±5.0% versus 77±6.0%) with the homograft (respectively) and comparable reduction in left ventricular mass index relative to other prosthesis types. Over 6000 individual patients were included in the selected 15 case series. Weighted mean operative mortality, neurological event rate and five-year actuarial survival was 5.2%, 5.5% and 77.8%, respectively.

CONCLUSION: The FSB performed comparably against alternative prostheses regarding in-hospital mortality, long-term survival and reduction in left ventricular mass index. Included case series demonstrated robust post-operative outcomes in both the short and long term.

Geriatric cardiac surgery: chronology vs. biology

Seco M, Edelman JJ, Forrest P, Ng M, Wilson MK, Fraser J, Bannon PG, Vallely MP

Heart Lung Circ 2014 Sep;23(9):794-801

PMID: 24851829

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Cardiac surgery is increasingly performed in elderly patients, and whilst the incidence of common risk factors associated with poorer outcome increases with age, recent studies suggest that outcomes in this population may be better than is widely appreciated. As such, in this review we have examined the current evidence for common cardiac surgical procedures in patients aged over 70 years. Coronary artery bypass grafting (CABG) in the elderly has similar early safety to percutaneous intervention, though repeat revascularisation is lower. Totally avoiding instrumentation of the ascending aorta with off-pump techniques may also reduce the incidence of neurological injury. Aortic valve replacement (AVR) significantly improves quality of life and provides excellent short- and long-term outcomes. Combined AVR and CABG carries higher risk but late survival is still excellent. Mini-sternotomy AVR in the elderly can provide comparable survival to full-sternotomy AVR. More accurate risk stratification systems are needed to appropriately select patients for transcatheter aortic valve implantation. Mitral valve repair is superior to replacement in the elderly, although choosing the most effective method is important for achieving maximal quality of life. Minimally-invasive mitral valve surgery in the elderly has similar postoperative outcomes to sternotomy-based surgery, but reduces hospital length of stay and return to activity. In operative candidates, surgical repair is superior to percutaneous repair. Current evidence indicates that advanced age alone is not a predictor of mortality or morbidity in cardiac surgery. Thus surgery should not be overlooked or denied to the elderly solely on the basis of their “chronological age”, without considering the patient’s true “biological age”.

Veno-arterial extracorporeal membrane oxygenation for high-risk cardiac catheterisation procedures

Spina R, Forrest AP, Adams MR, Wilson MK, Ng MK, Vallely MP

Heart Lung Circ 2010 Dec;19(12):736-41

PMID: 20869915

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Extracorporeal membrane oxygenation (ECMO) provides circulatory or respiratory support, or both, to patients with severe but potentially reversible cardiac or respiratory failure refractory to standard therapy. The use of ECMO in the paediatric cardiac surgical population is established. Likewise, the use of ECMO for severe adult respiratory failure has recently been established and has been the subject of recent clinical trials. However, its use as a means of cardiac support in the adult population is not routine in clinical practice. We herein review the indications, technical procedure, complications and outcomes of extracorporeal membrane oxygenation as pertinent to cardiac disease in general, and specifically, to catheter-based interventions. We describe two cases of high-risk cardiac catheterisation laboratory procedures performed with veno-arterial ECMO support in adult patients who were deemed to be at unacceptably high risk for conventional open-heart surgery and cardiopulmonary bypass.