Long Term Outcomes Following Freestyle Stentless Aortic Bioprosthesis Implantation: An Australian Experience.

BACKGROUND: The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results. METHODS: A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes. RESULTS: The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease. CONCLUSIONS: We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.

The freestyle aortic bioprosthesis: a systematic review.

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.

Surgical aortic valve replacement in very elderly patients aged 80 years and over: evaluation of early clinical outcomes.

BACKGROUND: An increasing number of very elderly patients aged ≥80 years will require aortic valve replacement (AVR) for severe aortic stenosis (AS). Many are classified as high-risk surgical candidates. Transcatheter aortic valve implantation (TAVI) has been proposed as an alternative to surgical AVR (SAVR) for high-risk patients. We evaluated early clinical outcomes of very elderly patients undergoing SAVR to optimise TAVI candidate selection. METHODS: We conducted a retrospective case review of 132 consecutive patients aged ≥80 years undergoing isolated SAVR (49 patients) or combined SAVR/CABG (83 patients) during February 2002-January 2010 at a single tertiary referral hospital. Risk for cardiac surgery was calculated using the logistic EuroSCORE (ES(log)). Mortality and morbidity data were collected for the 30-day postoperative period. RESULTS: Thirty-day mortality rate was 8.3% for patients undergoing SAVR (6.1% for isolated SAVR and 9.6% for SAVR/CABG). Permanent stroke occurred in 3.8% and renal insufficiency in 7.6% of the cohort. Thirty-five percent of patients had left ventricular ejection fraction <50%, 67% had advanced symptoms (NYHA class III or IV), and 42% of patients were stratified as high-risk (ES(log)≥20%). CONCLUSIONS: SAVR can be performed in very elderly patients with acceptable operative morbidity and mortality. The outcomes at our institution are comparable to contemporary SAVR and TAVI outcomes.

The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society grading system has limited prognostic significance in advanced resected pulmonary adenocarcinoma.

INTRODUCTION: The International Association for the Study of Lung Cancer, the American Thoracic Society and the European Respiratory Society (IASLC/ATS/ERS) system which subclassifies lung adenocarcinoma into five distinct types has been widely adopted. We assessed the prognostic value of subclassifying adenocarcinoma in this way in consecutive patients undergoing surgery. METHODS: All patients at our institution undergoing surgery for lung carcinoma between 2000 and 2010 were identified. The original pathology slides were independently reviewed and reclassified according to the 2011 IASLC/ATS/ERS grading and the American Joint Committee on Cancer (AJCC) 7 edition 2009 staging systems. RESULTS: We identified 270 patients including 152 with adenocarcinoma histology with long-term follow-up. Using the Kaplan-Meier method, the calculated 5 year survival for each of the adenocarcinoma categories were papillary-predominant 80%, lepidic-predominant 71%, micropapillary-predominant 55%, acinar-predominant 43%, solid-predominant 39% and invasive mucinous adenocarcinoma 38%. The AJCC stage was a very strong predictor of survival (p<0.001). The IASLC/ATS/ERS subclassification of adenocarcinoma demonstrated a trend as a prognostic marker but failed to reach statistical significance in univariate or multivariate analysis. CONCLUSION: Although the IASLC/ATS/ERS classification has been validated by several studies in stage I tumours, further studies of larger cohorts will be required to show prognostic value in unselected lung carcinoma undergoing surgery with curative intent.

Anaortic techniques reduce neurological morbidity after off-pump coronary artery bypass surgery.

BACKGROUND: Stroke remains one of the most devastating complications of cardiac surgery. Advocates of off-pump coronary revascularisation (OPCAB) maintain that post-operative neurologic morbidity is reduced by avoiding aortic cannulation and cross-clamping, and by eliminating the systemic effects of cardiopulmonary bypass. We sought to determine whether completing off-pump coronary surgery without any aortic manipulation ("anaortic" technique) afforded any additional neurological protection, as compared to off-pump grafting in which the aorta was utilised for graft inflow. METHODS: A comprehensive review of prospectively collected data was undertaken of all patients undergoing OPCAB in our institution between January 2002 and December 2006. Cases requiring intra-operative conversion to cardiopulmonary bypass were excluded from further analysis. Patients having OPCAB surgery with aortic manipulation were compared to those having OPCAB surgery without aortic manipulation. Multiple logistic regression was used to identify possible predictors of post-operative neurologic morbidity, with particular focus on the role of aortic manipulation. RESULTS: During the period of review, 1758 patients underwent OPCAB, of which 1201 (68.3%) were completed without aortic manipulation, constituting the "anaortic" cohort. This group was compared with the remaining 557 patients, which included fashioning at least one aorto-conduit anastomosis, utilising either a side-biting aortic clamp or a no-clamp proximal anastomotic device. The two groups of patients were well-matched with respect to risk factors for adverse neurologic outcomes. Nine patients sustained focal neurological deficits (transient or permanent) in the peri-operative period, constituting a stroke rate of 0.51% for the entire series. The incidence of peri-operative neurological deficit in the anaortic group was 0.25% compared with 1.1% in the aortic manipulation group (odds ratio (OR) 0.23, 95% confidence interval (CI) 0.06-0.92, p=0.037). Advanced age was also associated with peri-operative neurological injury (OR 1.1, 95% CI 1.01-1.20, p=0.017). CONCLUSIONS: Off-pump coronary artery surgery is associated with a low incidence of peri-operative stroke. Completing the surgical procedure without manipulating the ascending aorta in any way ("anaortic" technique) offers additional neurological protection and should be the goal in all suitable off-pump coronary cases.

HeartPatch implanted direct cardiac compression: effect on coronary flow and flow patterns in acute heart failure sheep.

A novel HeartPatch direct cardiac compression (DCC) device has been shown to effectively restore circulatory parameters in sheep with acute heart failure (HF). Its effect on the coronary circulation and myocardial perfusion, however, remains uncertain. The effect of DCC assist on coronary artery blood flow (CABF) and its patterns in acute HF sheep were examined in this study. Ten sheep (51 +/- 6 kg) were implanted with a heart patch on each of the left ventricular and right ventricular free walls 1 week before study. Stable HF [cardiac output (CO) at 51 +/- 8% of baseline] induced by intravenous esmolol resulted in CABF decreasing to 53 +/- 16% of baseline (p < 0.001). DCC device activation did not alter CABF (54 +/- 15% of baseline, N.S.) but was accompanied by increases in both peak antegrade and retrograde flow velocity (161 +/- 75%, p < 0.001 and 413 +/- 377%, p < 0.001). A shift in the proportion of flow occurring in diastole (%DF) also was observed: baseline, 81 +/- 9%; HF, 82 +/- 6%; DCC assist, 121 +/- 16% (p < 0.001). Despite significant changes in coronary artery flow pattern resulting from DCC of the failing heart, total antegrade coronary flow was maintained. These findings suggest that myocardial perfusion is not compromised by DCC.

Functional recovery of the native heart after cardiomyoplasty in sheep with heart failure: passive and dynamic effects of volume loading.

BACKGROUND: Dynamic cardiomyoplasty (d-CMP) encourages reverse remodeling and improved contractility and stroke work (SW) efficiency of the failing native heart. This contrasts with passive cardiomyoplasty (p-CMP), which provides "passive girdling." To further evaluate pump recovery we assessed native left ventricular performance (without assist) 6 months after dynamic and passive CMP in sheep with heart failure with acute volume loading. METHODS: Heart failure (left ventricular ejection fraction 26%+/-8%) induced by coronary microembolization was followed by CMP in 11 sheep. After 8 weeks of muscle "training," paced cardiac assist was undertaken in the d-CMP group (n = 6). Five sheep with heart failure served as controls. Six months later the pressure-volume relationship was derived before and after volume loading by colloid solution. Latissimus dorsi muscle pacing was previously ceased in the d-CMP group. RESULTS: Volume loading increased left ventricular end-diastolic volume and pressure in all groups. After volume loading in d-CMP, the SW and pressure-volume area were increased, and SW efficiency remained unchanged. In p-CMP neither variable changed, whereas in control heart failure SW efficiency decreased due to a rise in pressure-volume area with stable SW. CONCLUSIONS: Based on response to volume loading, the failing native heart after 6 months of d-CMP showed functional recovery from "active girdling," whereas p-CMP prevented functional deterioration through passive girdling. The failing control heart progressively deteriorated.