Research

Davies RA, Black D, Jeremy RW, Bannon PG, Bayfield MS, Hendel PN, Hughes CF, Wilson MK, Vallely MP

Heart Lung Circ 2011 Nov;20(11):704-11

PMID: 21872527

Abstract

BACKGROUND: Aortic arch replacement is a complicated and high risk procedure. There have been many advances over recent years. We review the changes in our unit’s techniques and outcomes over the past 22 years.

METHODS: Data were collated from databases and medical records for all patients who underwent aortic arch replacement surgery from January 1989 to December 2010. The patients were divided into two groups – Group A (1989-2005) and Group B (2006-2010). Data were analysed to compare early and late series patients’ outcomes. Logistic regression was used to identify variables that predicted mortality.

RESULTS: Seventy-five eligible patients (56 males; mean age: 57.5 years; Group A: 40, Group B 35) were identified. There were great changes in the technique and the methods of cerebral protection. The overall mortality rate was 30.7% – Group A: 50% and Group B: 8.6% (p<0.001). Overall permanent neurological dysfunction was 23.7% – Group A: 40% and Group B: 11.8% (p=0.012). Cardiovascular disease and circulatory arrest time were significant predictors of mortality.

CONCLUSIONS: Increased experience and volume and advances in techniques over 22 years have resulted in major improvements in outcomes for patients having aortic arch replacement, allowing the procedure to be performed with greatly improved outcomes.

Cooper EA, Edelman JJ, Wilson MK, Bannon PG, Vallely MP

Heart Lung Circ 2011 Nov;20(11):694-703

PMID: 21862405

Abstract

Elderly and high-risk patients are increasingly being considered for myocardial revascularisation. Most trials comparing the various options for revascularisation exclude elderly and ‘high-risk’ patients. We have reviewed the options for myocardial revascularisation for elderly patients, and for patients with a number of common ‘high-risk’ co-morbidities–diabetes mellitus, renal insufficiency, poor left ventricular ejection fraction, peripheral vascular disease, left main coronary artery disease and chronic obstructive pulmonary disease–with a focus on coronary artery bypass grafting without the use of cardiopulmonary bypass and aortic manipulation.

Ramponi F, Vallely MP

Heart Lung Circ 2011 Sep;20(9):606-7

PMID: 22132418

Abstract

Cao C, Yan TD, Bannon PG, McCaughan BC

Ann. Surg. Oncol. 2011 Oct;18(10):2973-9

PMID: 21512863

Abstract

BACKGROUND: Extrapleural pneumonectomy (EPP) has been shown to improve long-term survival outcomes in selected patients with malignant pleural mesothelioma (MPM). The present study aimed to evaluate potential prognostic factors on overall survival for patients who underwent EPP for MPM and to examine the patient selection process in major referral centers that perform EPP.

METHODS: A systematic review of the current literature was performed using 5 electronic databases. Relevant studies with prognostic data on overall survival for patients with MPM treated by EPP were included for review. Two reviewers independently assessed each included study.

RESULTS: A total of 17 studies from 13 institutions containing the most updated and complete data on prognostic factors for patients with MPM who underwent EPP were included for review. A number of quantitative, clinical, and treatment-related factors were identified to have significant impact on overall survival.

CONCLUSIONS: Patients with nonepithelial MPM and nodal involvement have consistently demonstrated to have a worse prognosis after EPP. Their eligibility as candidates for EPP should be questioned. The preoperative patient selection process currently differs greatly between institutions and should focus on identifying patients with nonepithelial histologic subtypes and nodal involvement to exclude them as EPP surgical candidates in the future.

Kirschner MB, Kao SC, Edelman JJ, Armstrong NJ, Vallely MP, van Zandwijk N, Reid G

PLoS ONE 2011;6(9):e24145

PMID: 21909417

Abstract

The presence of cell-free microRNAs (miRNAs) has been detected in a range of body fluids. The miRNA content of plasma/serum in particular has been proposed as a potential source of novel biomarkers for a number of diseases. Nevertheless, the quantification of miRNAs from plasma or serum is made difficult due to inefficient isolation and lack of consensus regarding the optimal reference miRNA. The effect of haemolysis on the quantification and normalisation of miRNAs in plasma has not been investigated in great detail. We found that levels of miR-16, a commonly used reference gene, showed little variation when measured in plasma samples from healthy volunteers or patients with malignant mesothelioma or coronary artery disease. Including samples with evidence of haemolysis led to variation in miR-16 levels and consequently decreased its ability to serve as a reference. The levels of miR-16 and miR-451, both present in significant levels in red blood cells, were proportional to the degree of haemolysis. Measurements of the level of these miRNAs in whole blood, plasma, red blood cells and peripheral blood mononuclear cells revealed that the miRNA content of red blood cells represents the major source of variation in miR-16 and miR-451 levels measured in plasma. Adding lysed red blood cells to non-haemolysed plasma allowed a cut-off level of free haemoglobin to be determined, below which miR-16 and miR-451 levels displayed little variation between individuals. In conclusion, increases in plasma miR-16 and miR-451 are caused by haemolysis. In the absence of haemolysis the levels of both miR-16 and miR-451 are sufficiently constant to serve as normalisers.

Rahnavardi M, Yan TD, Bannon PG, Wilson MK

Interact Cardiovasc Thorac Surg 2011 Aug;13(2):189-97

PMID: 21571910

Abstract

A best evidence topic was written according to a structured protocol. The question addressed was whether the reimplantation (David) technique or the remodeling (Yacoub) technique provides the optimum event free survival in patients with an aortic root aneurysm suitable for an aortic valve-sparing operation. In total, 392 papers were found using the reported search criteria, of which 14 papers provided the best evidence to answer the clinical question. A total of 1338 patients (Yacoub technique in 606 and David technique in 732) from 13 centres were included. In most series, cardiopulmonary bypass time and aortic cross-clamp time were longer for the David technique compared to the Yacoub technique. Early mortality was comparable between the two techniques (0-6.9% for the Yacoub technique and 0-6% for the David technique). There is a tendency for a higher freedom from significant long-term aortic insufficiency in the David group than the Yacoub group, which does not necessarily result in a higher reoperation rate in the Yacoub group. In the largest series reported, freedom from a moderate-to-severe aortic insufficiency at 12 years was 82.6 ± 6.2% in the Yacoub and 91.0 ± 3.8% in the David group (P=0.035). Freedom from reoperation at the same time point was 90.4 ± 4.7% in the Yacoub group and 97.4 ± 2.2% in the David group (P=0.09). In another series, freedom from reoperation at a follow-up time of about four years was 89 ± 4% in the Yacoub group and 98 ± 2% in the David group. Although some authors merely preferred the Yacoub technique for a bicuspid aortic valve, the accumulated evidence in the current review indicates comparable results for both techniques in a bicuspid aortic valve. Current evidence is in favour of the David rather than the Yacoub technique in pathologies such as Marfan syndrome, acute type A aortic dissection, and excessive annular dilatation that may impair aortic root integrity. Careful selection of patients for each technique and successful restoration of normal cusp geometry are the keys to success in aortic valve-sparing operations.

Ramponi F, Yan TD, Vallely MP, Wilson MK

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

PMID: 21482577

Abstract

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.

Yan TD, Cao CQ, Boyer M, Tin MM, Kennedy C, McLean J, Bannon PG, McCaughan BC

Ann Thorac Cardiovasc Surg 2011;17(3):243-9

PMID: 21697784

Abstract

BACKGROUND: There has been an evolving role of surgery for malignant pleural mesothelioma (MPM) over the past 25 years. The objective of this study was to investigate whether the survival results for MPM patients after surgery have improved within this time period by an analysis of a prospective cohort of 540 patients.

METHODS: Five hundred and forty consecutive patients with MPM were treated by a thoracic surgical team. These patients were categorized into two groups: Group I (before September 1999, n = 270) and Group II (after September 1999, n = 270). The two groups were compared for clinicopathologic data and survival results. The statistical analyses of all prognostic parameters used overall survival as the endpoint.

RESULTS: Group II had higher proportions of epithelial tumors and patients who had preoperative PET scan, extrapleural pneumonectomy (EPP), postoperative radiotherapy and pemetrexed chemotherapy. The overall survival results were significantly better in Group II compared with Group I (p = 0.004). Four factors were found to be independently associated with an improved survival in multivariate analysis: epithelial subtype (p 100 cases (p = 0.006), patients who underwent EPP (p = 0.001) and those who received pemetrexed chemotherapy (p = 0.016). The median survival for patients selected for EPP was 20 months, as compared to 9 months for pleurodesis/decortication and pleurodesis.

CONCLUSIONS: Significant improvement of overall survival results has been achieved in the more recent 270 MPM patients through accumulated experience in a specialist treatment center.

Ramponi F, Vallely MP, Stephen MS, Bannon PG, Bayfield MS, White GH

J. Endovasc. Ther. 2011 Jun;18(3):350-4

PMID: 21679073

Abstract

PURPOSE: To describe a technique for transapical wire-assisted endograft deployment under rapid ventricular pacing for a type B dissection involving the proximal left subclavian artery and extending to the aortic bifurcation.

CASE REPORT: A 58-year-old man presented with a symptomatic thoracic aneurysm as a complication of a chronic type B dissection, with a short proximal neck in zone 1. After arch vessel debranching, the patient underwent endoluminal repair with deployment of a closed web, tapered Valiant thoracic endograft over a through-and-through wire from the left groin to the apex of the left ventricle, using rapid ventricular pacing to reduce cardiac output. The remaining dissected aorta was covered with a second Valiant endograft down to the distal third of the descending thoracic aorta and bare Z stents down to the aortic bifurcation to re-expand the true lumen. A freeflow Valiant endograft was deployed as a proximal extension to treat a proximal type I endoleak. The recovery was complicated by retrograde type A aortic dissection, considered secondary to the bare stent. The complication was repaired surgically; postoperative computed tomography after recovery was unremarkable.

CONCLUSION: Transapical wire-assisted deployment with rapid ventricular pacing is feasible and may provide improved stability for stenting within the aortic arch. The use of a stent-graft with a proximal bare stent is associated with a higher risk of retrograde extension of the dissection and warrants lifelong imaging follow-up.