Michael Poullis

Validation of EuroSCORE II in a modern cohort of patients undergoing cardiac surgery.

OBJECTIVE We aimed to validate the new EuroSCORE II risk model in a contemporary cardiac surgery practice in the United Kingdom (UK). METHODS The original logistic EuroSCORE was compared to EuroSCORE II with regard to accuracy of predicting in-hospital mortality. Analysis was performed on isolated coronary artery bypass grafts (CABG; n = 2913), aortic valve replacement (AVR; n = 814), mitral valve surgery (MVR; n = 340), combined AVR and CABG (n = 517), aortic (n = 350) and miscellaneous procedures (n = 642), and the above cases combined (n = 5576). RESULTS In a single-institution experience, EuroSCORE II is a reasonable risk model for in-hospital mortality from isolated CABG (C-statistic 0.79, Hosmer-Lemeshow P = 0.052) and aortic procedures (C-statistic 0.81, Hosmer-Lemeshow P = 0.43), and excellent for mitral valve surgery (C-statistic 0.87, Hosmer-Lemeshow P = 0.6). EuroSCORE II is better than the original EuroSCORE, using contemporaneous data for combined AVR and CABG operations (C-statistic 0.74, Hosmer-Lemeshow P = 0.38). However, EuroSCORE II failed to improve on the original EuroSCORE model for isolated AVR (C-statistic 0.69, Hosmer-Lemeshow P = 0.07) and miscellaneous procedures (C-statistic 0.70, Hosmer-Lemeshow P = 0.99). EuroSCORE II has better calibration than the original EuroSCORE or the Society of Cardiothoracic Surgeons of Great Britain and Ireland (SCTS) modified EuroSCORE for cumulative sum survival (CUSUM) curves. CONCLUSIONS EuroSCORE II improves on the original logistic EuroSCORE, though mainly for combined AVR and CABG cases. Concerns still exist, however, over its use for isolated AVR procedures, aortic surgery and miscellaneous procedures. There is still room for improvement in risk modelling.

Ascending aortic curvature as an independent risk factor for type a dissection, and ascending aortic aneurysm formation: a mathematical model

OBJECTIVE To develop a mathematical model to demonstrate that ascending aortic curvature is an independent risk factor for type A dissections, in addition to hypertension, bicuspid aortic valve, aneurysm of ascending aorta, and intrinsic aortic tissue abnormalities, like Marfans syndrome. METHODS A steady state one-dimensional flow analysis was performed, utilising Newtons third law of motion. Five different clinical scenarios were evaluated: (1) effect of aortic curvature; (2) effect of beta-blockers, (3) effect of patient size, (4) forces on a Marfans aorta, and (5) site of entry flap in aortic dissection. RESULTS Aortic curvature increases the forces exerted on the ascending aorta by a factor of over 10-fold. Aortic curvature can cause patients with a systolic blood pressure of 8 0mmHg to have greater forces exerted on their aorta despite smaller diameters and lower cardiac outputs, than patients with systolic blood pressures of 120 mmHg. In normal diameter aortas, beta-blockers have minimal effect compared with aortic curvature. Aortic curvature may help to explain why normal diameter aortas can dissect, and also that the point of the entry tear may be potentially predictable. Aortic curvature has major effects on the forces exerted on the aorta in patients with Marfans syndrome. CONCLUSIONS Aortic curvature is relatively more important that aortic diameter, blood pressure, cardiac output, beta-blocker use, and patient size with regard to the force acting on the aortic wall. This may explain why some patients with normal diameter ascending aortas with or without Marfans syndrome develop type A dissections and aneurysms. Aortic curvature may also help to explain the site of entry tear in acute type A dissection. Further clinical study is needed to validate this studys finding.

Long-term survival after coronary artery bypass surgery stratified by EuroSCORE

OBJECTIVES Coronary artery bypass grafting (CABG) is performed for symptoms and for prognostic reasons. The EuroSCORE is widely utilized as a pre-operative risk prediction tool. We evaluated our long-term survival figures based on EuroSCORE. METHODS A prospective database was retrospectively analysed and cross correlated with the UK strategic tracking service to evaluate survival after primary CABG. Patients were grouped based on their logistic EuroSCORE 0 to <5, 5 to <10, 10 to <15, 15 to <20, 20 to <25 and ≥25. RESULTS We analysed 13,337 primary cardiac procedures. A total of 9961 procedures had a logistic EuroSCORE of 0 to <5, 2041 of 5 to <10, 636 of 10 to <15, 281 of 15 to <20, 137 of 20 to <25 and 281≥25. Long-term survival is significantly affected by logistic EuroSCORE, P < 0.001. Patients with a logistic EuroSCORE <5% had significantly better initial survival and a lower rate of death over a 10-year period, P<0.001. Patients with a logistic score over 25 had a significantly worse 5-year survival, P<0.001. Logistic EuroSCORE was poor at predicting survival when >5 and <25. Cox multivariate regression and neuronal network analysis confirmed that the additional factors, diabetes, body mass index (BMI), post-operative myocardial creatinine kinase myocardial isoenzyme (CKMB) and left internal mammary artery (LIMA) usage, which are not incorporated in EuroSCORE significantly predict long-term survival. CONCLUSIONS Logistic EuroSCORE is a reasonable approximation for long-term survival after CABG, if the score is <5; however, its predictive capacity is limited due to the absence of LIMA usage, BMI, diabetes and CKMB in its calculation, all of which are significant factors affecting long-term survival.

A propensity-matched comparison of survival after lung resection in patients with a high versus low body mass index

OBJECTIVES An inverse relationship between body mass index (BMI) and the risk of lung cancer has been reported in several studies. In this study, we aimed to assess whether BMI can affect survival after lung resection for cancer. METHODS We reviewed patient data for a 10-year period; 337 patients with BMI ≥ 30 who underwent lung resection for non-small cell lung cancer were identified. This group of patients was matched at a ratio of 1:1 to a group with BMI <30 and with similar characteristics such as sex, age, lung function test, history of smoking, diabetes, peripheral vascular disease, stroke, myocardial infarction, chronic obstructive pulmonary disease (COPD), procedure type, histology and stage of tumour. We also used the Kaplan-Meier survival curves before and after matching for the above mentioned patient characteristics. RESULTS Before adjusting for the preoperative and operative characteristics, despite more history of diabetes, hypertension and renal impairment in patients with BMI ≥ 30 compared to those with BMI <30 (BMI = 18.5-30 and < 8.5), the survival rate was found to be significantly higher when analysed univariately (P = 0.02). This difference remained significant after adjusting for all the characteristics, suggesting a significantly higher survival rate in the group with BMI ≥ 30 (P = 0.04). CONCLUSIONS Unlike in breast cancer, a high BMI in lung cancer patients after resection has protective effects. This may be due to the better nutritional status of the patient, a less aggressive cancer type that has not resulted in weight loss at the time of presentation or it may be due to certain hormones released from the adipose tissue. BMI can be a predictor of outcome after lung resection in cancer patients.

Preoperative red cell distribution width in patients undergoing pulmonary resections for non-small-cell lung cancer

OBJECTIVES Red cell distribution width (RDW) has been identified as an independent risk factor with regard to prognosis in patients with cardiac disease. We sought to investigate the association of RDW in patients undergoing lung resections for non-small-cell lung cancer with respect to in-hospital morbidity, mortality and long-term survival. METHODS Analysis of consecutive patients on a validated prospective thoracic surgery database was performed for those undergoing potentially curative resections at a single institution. Univariate and multivariate analyses were performed for postoperative invasive and non-invasive ventilation, superficial wound infections, length of hospital stay, in-hospital mortality and long-term survival. RESULTS Overall mortality was 1.9% for all cases (n = 917). The median follow-up was 6.8 years. Univariate analysis demonstrated that RDW has a significant effect on hospital length of stay (P < 0.001), in-hospital mortality rates (P < 0.001), postoperative invasive and non-invasive ventilation (P < 0.001), superficial wound infections (P = 0.06) and long-term survival (P < 0.0001). Multivariate analysis revealed that RDW is a significant factor determining postoperative invasive and non-invasive ventilation, superficial wound infections, length of hospital stay, in-hospital mortality and long-term survival. Confounding factor analysis revealed that in the absence of anaemia, RDW was still a significant factor in the above analysis. CONCLUSIONS RDW is a significant factor after risk adjustment, determining in-hospital morbidity, mortality and long-term survival in patients post-potentially curative resections for non-small-cell lung cancer. Further work is needed to elucidate the exact mechanism of RDW impact on in-hospital morbidity, mortality and long-term survival. We speculate that subtle bone marrow dysfunction may be an issue.

A need for speed? Bypass time and outcomes after isolated aortic valve replacement surgery

OBJECTIVES To determine in the modern era if cardiopulmonary bypass (CPB) time has a significant effect on postoperative morbidity, mortality and long-term survival in patients undergoing isolated aortic valve replacement (AVR) surgery. METHODS Analysis of a prospectively collected cardiac surgery database was performed. Uni- and multivariate analysis on the need of resternotomy for bleeding, mediastinal blood loss, intensive care unit (ICU) length of stay, hospital length of stay, in-hospital mortality and long- term survival was performed. Only patients with a cross-clamp time <90 min were analysed to exclude technical issues confounding the results. RESULTS A total of 1863 isolated first-time AVR procedures were analysed, with an in-hospital mortality rate of 2.4%. The rate of long-term follow-up achieved was 100%. Univariate analysis revealed that CPB time (minutes) had no significant effect on resternotomy (P = 0.5), creatinine kinase muscle-brain isoenzyme (CKMB) release (P = 0.8) and long-term survival (P = 0.06), but was significantly associated with mediastinal blood loss (P = 0.01), ICU length of stay (P = 0.02), hospital length of stay (P = 0.03) and in-hospital mortality (P < 0.001). Multivariate analysis identified that bypass time (min) was a significant factor associated with mediastinal blood loss (P < 0.001), ICU length of stay (P = 0.01), postoperative length of stay (P < 0.001) and in-hospital mortality (odds ratio [OR] 1.02, 95% CI 1.01-1.04, P = 0.01), but not long-term survival. Multivariate analysis identified that era of surgery had no significant effect on CKMB release (P = 0.2), mediastinal blood loss (P = 0.4) and in-hospital mortality (P = 0.9), but the latter era of this study was significantly associated with a reduced postoperative length of stay (P < 0.001), reduced ICU length of stay (P < 0.001), reduced need for resternotomy for bleeding (OR 0.62, 95% CI 0.41-0.94, P = 0.02) and improved long-term survival (hazard ratio 0.76, 95% CI 0.59-0.96, P = 0.02). Adjusting for era made no difference with respect to the above study findings. CONCLUSIONS Despite improvements over time with regard to morbidity, mortality and long-term survival, CPB time remains a significant factor determining mediastinal blood loss, ICU and hospital length of stay, and in-hospital mortality.

Smoking status at diagnosis and histology type as determinants of long-term outcomes of lung cancer patients

OBJECTIVES The study aimed to determine the importance of smoking status at operation and histology type with regard to long-term survival after potential curative surgery for lung cancer. METHODS We analysed a prospectively validated thoracic surgery database (n = 2485). We benchmarked our 5-year survival against the International Association for the Study of Lung Cancer (IALSC) results. Univariate and Cox multivariate analyses were performed for the study group and for isolated adenocarcinoma and squamous carcinoma histological subtypes. RESULTS Benchmarking failed to reveal any differences in survival of our study cohort compared with the IALSC results, P = 0.16. Univariate analysis revealed that non-smokers have a statistically better long-term outcome, P < 0.0001, than ever smokers. Patients with adenocarcinoma, n = 1216, had a worse outcome in ever smokers, P = 0.006. In patients with squamous carcinoma, n = 1065, smoking status made no difference, P = 0.4. Long-term survival was not significantly different for adenocarcinoma or squamous carcinoma, P = 0.87. Cox multivariate analysis revealed that patients with adenocarcinoma who were current smokers had a significantly worse long-term survival compared with ex-smokers and non-smokers (hazard ratio: 1.26, 95 confidence interval: 1.01-1.56), P = 0.04. Age, body mass index, sex, T stage, N stage, predicted postoperative forced expiratory volume in one second (FEV1), residual disease, alcohol consumption and oral diabetes were additional significant factors affecting long-term survival. Pneumonectomy, pack years, bronchial resection margin, New York Heart Association class, hypertension, previous cerebrovascular event, diet or insulin-controlled diabetes and previous myocardial infarction were excluded by the analysis as significant risk factors. Smoking status did not affect long-term survival in patients with squamous cell carcinoma. CONCLUSIONS Smoking status at time of surgery does not effect long-term survival in patients with squamous cell carcinoma. Smoking status makes a significant difference to the long-term outcomes of patients with adenocarcinoma even after adjustment for their risk factors. This implies that a histological classification of adenocarcinoma may incorporate genetically diverse adenocarcinomas with regard to prognosis.

Preventing of chylothorax after oesophagectomy by routine pre-operative administration of oral cream

The anatomy of the thoracic duct varies considerably. This can make it difficult to locate during oesophageal surgery, especially in the fasted patient. We describe the technique of administering cream orally before primary oesophageal surgery, to aid in the identification of the thoracic duct. The duct along with other lymphatic channels can then be ligated as appropriate, helping to reduce the incidence of post-operative chylothorax.

The long-term effects of developing renal failure post-coronary artery bypass surgery, in patients with normal preoperative renal function

OBJECTIVES Renal failure post-cardiac surgery is associated with an increased in hospital morbidity and mortality. We investigated the effect of new onset renal risk, injury or failure [risk, injury, failure, loss and end-stage kidney disease (RIFLE)] post-coronary artery bypass graft (CABG) on long-term survival, in patients with normal preoperative renal function. METHODS The effect of developing postoperative renal risk, injury or failure as defined by the RIFLE criteria on the long-term survival of patients undergoing isolated CABG with a normal renal function was studied. Two separate multivariate analyses were performed based on preoperative serum creatinine or glomerular filtration rate (GFR). Univariate, multivariate, interaction and confounding factor analyses were performed. RESULTS A total of 4029 isolated CABG patients were included in the study. 46.5% of patients had chronic kidney disease (CKD) stage 1 (GFR ≥90 ml/min/1.73 m(2)), 50.4% had CKD stage 2 (GFR 60-89 ml/min/1.73 m(2)) and 3.1% had CKD stage 3 (GFR 30-59 ml/min/1.73 m(2)) on admission, despite having a normal serum creatinine. The study group had a median follow-up of 3.6 years (95% CI 0-13.7). Renal risk, injury and failure were associated with a significantly reduced long-term survival (P < 0.001). In patients with normal preoperative serum creatinine, Cox regression analysis revealed that age (P = 0.026), preoperative creatinine (P =0.006) and logistic EuroSCORE (P < 0.0001) were significant factors in addition to the development of postoperative renal risk, injury or failure (P < 0.0001), with regard to determining long-term survival. A confounding factor analysis revealed that discharge creatinine (P = 0.0001) and discharge GFR (P = 0.0006) were significant determinants of long-term survival. In patients with a preoperative GFR >90 ml/min, Cox regression analysis revealed that diabetes (P = 0.004) sex (P = 0.019) and logistic EuroSCORE (P < 0.0001), were also significant factors in addition to the development of postoperative renal risk, injury or failure (P = 0.0001) with regard to determining long-term survival. A significant interaction between diabetes and the development of renal risk, injury or failure exists (P = 0.04). A confounding factor analysis revealed that discharge creatinine was a significant determinant (P = 0.0001) of long-term survival, and discharge GFR was not. CONCLUSIONS Despite being a biochemically reversible process, the development of renal risk, injury and failure as defined by the RIFLE criteria post-cardiac surgery in patients with a normal preoperative renal function is associated with a significantly worse long-term outcome.

Clinical Upstaging of Non-Small Cell Lung Cancer That Extends Across the Fissure: Implications for Non-Small Cell Lung Cancer Staging

BACKGROUND Little data exist as to the long-term outcome of non-small cell lung cancer that extends across the fissure into the adjacent lobe that requires either a bilobectomy or a lobectomy and wedge resection. METHODS Lobectomy survival data was benchmarked with the International Association for the Study of Lung Cancer (IALSC) dataset. Matched analysis of a prospective thoracic surgery database of 1,020 patients who had undergone lobectomy during a 6-year period was analyzed to elucidate the effect on long-term survival of tumors that extend across the interlobar fissure. RESULTS Benchmarking revealed our data are not significantly different from the IALSC dataset, allowing survival recommendations to be drawn. Histopathologic staging of matched patients was IA, 11.7%; IB, 51.1%; IIA, 1.7%; IIB, 21.1%; IIIA, 10.0%; IIIB, 2.8%; and IV, 1.7%. Stage I tumors crossing the interlobar fissure had a reduction in survival that is significant (10% to 15%) after 5 years (p = 0.037). The 5-year survival for stage I tumors extending across a lung fissure was 50%. This places the 5-year survival between stage I and II (60% and 40%, respectively). There was no difference in survival for tumors stage IIA and above with regard to importance of interlobar extension. The number of patients was too small to detect a significant difference between bilobectomy versus lobectomy and wedge. CONCLUSIONS Non-small cell lung cancer that extends across the fissure into an adjacent lobe requiring a bilobectomy or a lobectomy and wedge resection has a 5-year survival between stages I and II.