Alex Cale

Off-pump Coronary Artery Bypass (OPCAB) surgery reduces risk-stratified morbidity and mortality: A United Kingdom multi-center comparative analysis of early clinical outcome

Objective—Off-Pump Coronary Artery Bypass (OPCAB) surgery is gaining more popularity worldwide. The aim of this United Kingdom (UK) multi-center study was to assess the early clinical outcome of the OPCAB technique and perform a risk-stratified comparison with the conventional Coronary Artery Bypass Grafting (CABG) using the Cardio-Pulmonary Bypass (CPB) technique. Methods—Data were collected on 5,163 CPB patients from the database of the National Heart and Lung institute, Imperial College, University of London, and on 2,223 OPCAB patients from eight UK cardiac surgical centers, which run established OPCAB surgery programs. All patients had undergone primary isolated CABG for multi-vessel disease through a midline sternotomy approach, between January 1997 and April 2001. Postoperative morbidity and mortality were compared between the CPB and OPCAB patients after adjusting for case-mix. The mortality of the OPCAB patients was also compared, using risk stratification, to the mortality figures reported by the Society of Cardiothoracic Surgeons of Great Britain and Ireland (SCTS) based on 28,018 patients in the national database who were operated on between January 1996 and December 1999. Results—Morbidity and mortality were significantly lower in the OPCAB patients compared with the CPB patients and the UK national database of CABG patients, over the same period of time, after adjusting for case-mix. Conclusion—This study demonstrates that risk stratified morbidity and mortality are significantly lower in OPCAB patients than CPB patients and patients in the UK national database.

Hyperbaric oxygen preconditioning improves myocardial function, reduces length of intensive care stay, and limits complications post coronary artery bypass graft surgery ☆,☆☆,★

OBJECTIVE The objective of this study was to determine whether preconditioning coronary artery disease (CAD) patients with HBO(2) prior to first-time elective on-pump cardiopulmonary bypass (CPB) coronary artery bypass graft surgery (CABG) leads to improved myocardial left ventricular stroke work (LVSW) post CABG. The primary end point of this study was to demonstrate that preconditioning CAD patients with HBO(2) prior to on-pump CPB CABG leads to a statistically significant (P<.05) improvement in myocardial LVSW 24 h post CABG. METHODS This randomised control study consisted of 81 (control group=40; HBO(2) group=41) patients who had CABG using CPB. Only the HBO(2) group received HBO(2) preconditioning for two 30-min intervals separated 5 min apart. HBO(2) treatment consisted of 100% oxygen at 2.4 ATA. Pulmonary artery catheters were used to obtain perioperative hemodynamic measurements. All routine perioperative clinical outcomes were recorded. Venous blood was taken pre HBO(2), post HBO(2) (HBO(2) group only), and during the perioperative period for analysis of troponin T. RESULTS Prior to CPB, the HBO(2) group had significantly lower pulmonary vascular resistance (P=.03). Post CPB, the HBO(2) group had increased stroke volume (P=.01) and LVSW (P=.005). Following CABG, there was a smaller rise in troponin T in HBO(2) group suggesting that HBO(2) preconditioning prior to CABG leads to less postoperative myocardial injury. Post CABG, patients in the HBO(2) group had an 18% (P=.05) reduction in length of stay in the intensive care unit (ICU). Intraoperatively, the HBO(2) group had a 57% reduction in intraoperative blood loss (P=.02). Postoperatively, the HBO(2) group had a reduction in blood loss (11.6%), blood transfusion (34%), low cardiac output syndrome (10.4%), inotrope use (8%), atrial fibrillation (11%), pulmonary complications (12.7%), and wound infections (7.6%). Patients in the HBO(2) group saved US

Validation of four different risk stratification systems in patients undergoing off-pump coronary artery bypass surgery: a UK multicentre analysis of 2223 patients

116.49 per ICU hour. CONCLUSION This study met its primary end point and demonstrated that preconditioning CAD patients with HBO(2) prior to on-pump CPB CABG was capable of improving LVSW. Additionally, this study also showed that HBO(2) preconditioning prior to CABG reduced myocardial injury, intraoperative blood loss, ICU length of stay, postoperative complications, and saved on cost, post CABG.

Surgical nurse assistants in cardiac surgery: a UK trainee's perspective.

Background: Various risk stratification systems have been developed in coronary artery bypass graft surgery (CABG), based mainly on patients undergoing procedures with cardiopulmonary bypass. Objective: To assess the validity and applicability of the Parsonnet score, the EuroSCORE, the American College of Cardiology/American Heart Association (ACC/AHA) system, and the UK CABG Bayes model in patients undergoing off-pump coronary artery bypass surgery (OPCAB) in the UK. Methods: Data on 2223 patients who underwent OPCAB in eight cardiac surgical centres were collected. Predicted mortality risk scores were calculated using the four systems and compared with observed mortality. Calibration was assessed by the Hosmer–Lemeshow (HL) test. Discrimination was assessed using the receiver operating characteristic (ROC) curve area. Results: 30 of 2223 patients (1.3%) died in hospital. For the Parsonnet score the HL test was significant (p < 0.001) and the receiver operating characteristic curve (ROC) area was 0.74. For the EuroSCORE the HL test was also significant (p = 0.008) and the ROC area was 0.75. For the ACC/AHA system the HL test was non-significant (p = 0.7) and the ROC area was 0.75. For the UK CABG Bayes model the HL test was also non-significant (p = 0.3) and the ROC area was 0.81. Conclusions: The UK CABG Bayes model is reasonably well calibrated and provides good discrimination when applied to OPCAB patients in the UK. Among the other three systems, the ACC/AHA system is well calibrated but its discrimination power was less than for the UK CABG Bayes model. These data suggest that the UK CABG Bayes model could be an appropriate risk stratification system to use for patients undergoing OPCAB in the UK.

An unusual presentation of pedunculated thrombus in the distal arch of the aorta after splenectomy for B-cell lymphoma

OBJECTIVE To assess the impact of surgical nurse assistants on surgical training based on a comparative audit of case-mix and outcome of coronary revascularizations assisted by surgical nurse assistants vs. surgical trainees. METHODS Relevant recent articles on Calman reform of specialist training and European working time directive (EWTD) on junior doctor working hours were reviewed for the discussion. For the audit prospectively entered data of elective and expedite first time coronary artery bypass grafting cases from 2000 to 2003 were analysed. Group A (n=233, Consultant+Surgical nurse assistant), group B (n=1067, Consultant+Junior surgical trainee). Chi-square test, t-test and Fishers test were used as appropriate for statistical analysis. RESULTS Comparative preoperative variables were gender (P=0.8), body mass index (P=0.9), smoking (P=0.3), diabetes mellitus (P=0.2), hypertension (P=1), peripheral vascular disease (P=0.5), previous cerebrovascular accident (CVA)/transient ischemic attack (TIA) (P=0.3), renal dysfunction (P=0.4), preoperative rhythm disturbances (P=0.3), previous Q-wave myocardial infarction (MI) (P=0.4), Canadian Cardiovascular Society angina class (P=0.4), New York Heart Association heart failure class (P=0.4) and left ventricular function (P=0.4). Patients in group B were of higher risk due to age (P=0.01), coronary disease severity (P=0.05), left main stem disease (P=0.001), Parsonnet score (P=0.0001) and Euroscore (P=0.005. Regarding the myocardial protection technique, intermittent cross-clamp fibrillation was used more frequently in group A while antegrade-retrograde cold blood cardioplegia and off-pump coronary artery bypass were used more in group B (P=0.0001). The cross-clamp (P=0.0001) and operation time (P=0.0001) were significantly lower in group A despite a comparable mean number of grafts (P=0.2). There was no significant difference in the immediate postoperative outcome ventilation time (P=0.2), intensive care unit stay, postoperative stay (P=0.2), re-exploration for bleeding (P=0.5), inotrope+intra-aortic balloon pump (P=0.2), postoperative MI (P=0.9), postoperative rhythm disturbances (P=0.9), CVA/TIA (P=0.8), renal dysfunction (P=0.6), wound infection (P=0.7), sternal re-wiring (P=0.2), multi-organ failure (P=0.4) or mortality (P=0.1). CONCLUSIONS Surgical nurse assistants can be used effectively in low-risk cases without compromising postoperative results. However, initiatives to tackle the EWTD should be focused on areas that do not compromise the training needs of junior surgical trainees. An intermediate grade between the present senior house officer and registrar grades could be a way forward.

Hyperbaric oxygen: A novel technology for modulating myocardial ischemia-reperfusion via a single drug

A 59-year-old woman who was asymptomatic after a splenectomy for B-cell lymphoma was found to have a pedunculated mass filling 50% of the aortic lumen within the distal aortic arch on a routine follow-up computed tomographic scan of the chest (A/cover image, and B). She was referred to us with a differential diagnosis of tumor originating from the aortic wall. On transesophageal echocardiogram it seemed to be a solid mass rather than a floating thrombus. With suspicion of malignancy, it was decided to remove the mass surgically. Left thoracotomy was performed, and a 4-cm mass originating from the inner aspect of the distal aortic arch just above the remnant of the ductus arteriosus was excised on partial left heart bypass (C). The histology report showed a cylinder of pale hemorrhagic tissue, 4.0 1.0 0.8 cm, consisting of fibrin thrombus with a few atypical lymphoid cells present at one edge. However, this was insufficient for a firm diagnosis of malignancy. After surgery she received anticoagulant medication for 6 months. She remains well, with no evidence of recurrent thrombus after 3 years of follow-up. Nonaneurysmal aortic arch lesions are a frequent and a stillunderestimated source of stroke and peripheral embolization (in 10% of patients, the source of peripheral embolism cannot be identified). A floating thrombus in an apparently normal aortic arch is considered a life-threatening condition. Although rare, this diagnosis must not be overlooked in the search for etiology of recurrent and disseminated peripheral ischemic events, because of the significant morbidity and mortality related to a delayed diagnosis. Coagulopathies, atherosclerosis, trauma, malignancy, pregnancy, and previous aortic surgery are a few common causes of thrombus formation in this rare condition. There are various treatment options available, such as anticoagulation, balloon thrombectomy, stenting, and surgery. All these therapeutic modalities have their limitations; nonsurgical treatment involves high risk of embolism (reported as a 73% incidence of embolic events for highly mobile aortic thrombi as compared with 12% for immobile ones), ischemia, and stroke, whereas surgery has been reported with high mortality and morbidity. Complicated vascular surgical procedures have been performed for definitive treatment. Primary tumors of the aorta are rare, and only a few cases are reported in the literature; as a result of our suspicion of tumor, we aimed to remove the lesion in a controlled manner under bypass, because no standard approach

Comparison of the immediate post-operative outcome of two different myocardial protection strategies: antegrade–retrograde cold St Thomas blood cardioplegia versus intermittent cross-clamp fibrillation

Over the years, the anecdotal medical use of oxygen has demonstrated, in a non-evidence-based manner, that it may have wide-ranging clinical consequences. Although oxygen is a critical substrate in the alleviation of hypoxia, anoxia, and ischemia, paradoxically, it also functions as a deleterious metabolite during the reperfusion of previously ischemic tissues. In adding to this controversy, a spate of new pioneering work has identified hyperoxygenation (hyperoxia) and its metabolites as solely and purposefully demonstrating cellular and clinical benefit, particularly in the field of ischemic reperfusion injury (IRI). Furthermore, the beneficial effects of oxygen have been technologically augmented by administration at doses above atmospheric pressure and at higher concentrations. The novel technology that involves oxygen treatment at supra-atmospheric pressures in high concentrations is known as hyperbaric oxygen (HBO). Although the concept of hyperbaric oxygen has been around since the mid 20th century, it is only during the past decade or so that its therapeutic potential as a new technology-based drug has been exploited for the purposes of cellular tolerance and protection. HBO has recently been shown to be a useful adjunct in several models of IRI, including myocardial infarction. How it does this remains to be elucidated. This article attempts to bring into the spotlight some pertinent developments regarding HBO and myocardial IRI, while simultaneously stimulating intellect, thought, and discussion as to whether this novel technology—HBO—which consists of only a singular drug—oxygen—is a therapy that warrants further laboratory and clinical investigation as a therapeutic modality that may be safe and cost-effective, without producing significant adverse effects.

Can hyperbaric oxygen be used as adjunctive heart failure therapy through the induction of endogenous heat shock proteins

The objective of this study was to compare the immediate post-operative outcome of two myocardial protection strategies. Data of consecutive elective first time coronary artery bypass grafting (CABG) were analysed: Group A (n=671, antegrade-retrograde cold St Thomas blood cardioplegia) and Group B (n=783, intermittent cross-clamp fibrillation). Age, angina class, myocardial infarction (MI), pre-operative rhythm, respiratory disease, smoking, diabetes mellitus (DM), hypertension (HT), renal function, cerebrovascular disease, body mass index (BMI) and Parsonnet score were comparable. Significant differences existed in gender (P=0.02), peripheral vascular disease (PVD) (P=0.04), heart failure class (P=0.0001), left ventricular (LV) function (P=0.01), disease severity (P=0.02), left main stem (LMS) (P=0.02) and preinduction intra-aortic balloon pump(IABP) (P=0.08). Group A had more grafts (P=0.008), longer bypass (P=0.0001) and cross-clamp time (P=0.0001). Post-operative inotrope, MI, arrhythmias, neurological, renal complications, multi-organ failure, sternal re-wiring, ventilation, length of stay and mortality were comparable. There was higher IABP usage and longer intensive therapy unit (ITU) stay (P=0.01) in Group B. Chronic obstructive airway disease (COAD), renal dysfunction, cross-clamp time, bypass time, post-operative inotrope or IABP and re-exploration predicted longer ITU stay. Intermittent cross-clamp fibrillation is a versatile and cost-effective method of myocardial protection, with the immediate post-operative outcome comparable to antegrade-retrograde cold St Thomas blood cardioplegia in elective first-time CABG.

Short- and long-term outcomes of pneumonectomy in a tertiary center.

Heart failure (HF) is a chronic condition that is expected to increase in incidence along with increased life expectancy and an aging population. As the incidence of HF increases, the cost to national healthcare budgets is expected to run into the billions. The costs of lost productivity and increased social reliance on state support must also be considered. Recently, acute myocardial infarction (AMI) has come to be seen as the major contributing factor to HF. Although thrombolysis may restore coronary perfusion after an AMI, it may also introduce ischemic reperfusion injury (IRI). In an attempt to ameliorate sustained protein damage caused by IRI, endogenous chaperone proteins known as heat shock proteins (HSPs) are induced as a consequence of the stress of IRI. Recently, hyperbaric oxygen has been shown to induce the production of HSPs in noncardiac tissue, with a resultant protective effect. This current opinion review article suggests a possible role for hyperbaric oxygen, as a technologically modern drug, in augmenting the induction of endogenous HSPs to repair and improve the function of failing hearts that have been damaged by AMI and IRI. In addition, this simple, safe, noninvasive drug may prove useful in easing the economic burden of HF on already overextended health resources.

Extrapleural Pneumonectomy A Blessing or a Curse in the Management of Pleural Malignant Mesothelioma

Background Surgery is the most important therapeutic modality for lung cancer. Surgical outcomes are normally reported as 30-day or 90-day mortality or 5-year survival; 10-year survival is rarely mentioned in national data or international studies. Methods Three hundred and six patients (79% male) underwent pneumonectomy, mainly for lung cancer, from January 1998 to February 2013. Their short- and long-term outcomes up to September 2014 were analyzed retrospectively. The mean age was 64 years (range 22–82 years) and 24% were aged ≥70 years. Thoracoscore was used to calculate the risk of hospital mortality. Results Operative mortality was 4.5% whereas predicted mortality was 8%. The operative mortality for cancer patients was 3.3%; the national mortality for lung cancer is 6.5%. Only 2 patients died in hospital after a pneumonectomy in the last 5 years. Half of the patients who died in hospital were ≥70 years old; 29% (4 patients) died after urgent operations for nonmalignant disease. Overall 5- and 10-year survival was 32% and 20%. Median and mean survival was 26 and 57 months, respectively. Long-term survival was better in females aged <70 years, in left pneumonectomy patients, and in those with squamous cell lung cancer. Conclusion Our mortality for pneumonectomy was 50% less than the national mortality rate and significantly lower than that predicted by the Thoracoscore for lung cancer. This confirms that pneumonectomy is still an effective modality for the treatment of lung cancer, with low operative mortality and good long-term survival, especially in younger patients.