Is levosimendan effective in paediatric heart failure and post-cardiac surgeries?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was 'do children with heart failure post-cardiac surgery undergoing treatment with levosimendan have an acceptable haemodynamic improvement?' The use of levosimendan as a vasoactive drug is an accepted intervention for patients with altered haemodynamics post-cardiac surgeries. However, the role of levosimendan and its efficacy have been debated. Eleven relevant papers were identified, which represented the best evidence to answer the question. The author, journal, date, country of publication and relevant outcomes are tabulated. The 11 studies comprised 3 randomized trials, 2 of which compared levosimendan and milrinone. A single-centre randomized study that included 40 infants showed that cardiac output (CO) and cardiac index (CI) increased overtime in the levosimendan group compared with the milrinone group. The significant interaction for CO (P = 0.005) and CI (P = 0.007) indicated different time courses in the two groups. A similar, European randomized study undertaken on neonates (n = 63) showed better lactate levels [P = 0.015 (intensive care admission); P = 0.048 (after 6 h) with low inotropic scores in the levosimendan group. Although the length of mechanical ventilation and mortality were less, this was statistically insignificant. A retrospective cohort analysis (n = 13) in children reported a reduced use of dobutamine and improvement in the ejection fraction from 29.8 to 40.5% (P = 0.015) with the use of levosimendan. In a questionnaire-based study from Finland, 61.1% of respondents felt that it had saved the lives of some children when the other treatments had failed. No study reported any adverse effect attributable to use of levosimendan. In conclusion, the above studies were in favour of levosimendan as a safe and feasible drug providing potential clinical benefit in low cardiac output syndrome (LCOS) and post-cardiac surgeries when other vasoactive drugs were insufficient to maintain stable haemodynamics. A small sample size was indeed a limitation in all the above studies. Furthermore, it is best used as a rescue drug on a named-patient basis. A small sample size was indeed a limitation in all the above studies. Larger, well-designed trials are required to further evaluate the efficacy and feasibility of levosimendan in paediatric heart failure and post-cardiac surgeries.

In patients undergoing lung resection for non-small cell lung cancer, is lymph node dissection or sampling superior?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In patients undergoing lung resection for non-small cell lung cancer, is lymph node dissection or sampling superior?' Altogether 845 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that in stage I tumours there is little difference in survival when performing either mediastinal lymph node dissection (MLND) or lymph node sampling. However, survival is increased when performing MLND in stage II to IIIa tumours. Increased accuracy in staging is not observed with MLND. However, MLND reliably identifies more positive N2 nodes which may offer advantages in postoperative adjuvant treatment in more advanced disease.

Can thoracoscopic Heller's myotomy give equivalent results to the more usual laparoscopic Heller's myotomy in the treatment of achalasia?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'Can thoracoscopic Heller's myotomy (THM) give equivalent results to the more usual laparoscopic Heller's myotomy (LHM) in the treatment of achalasia?' Altogether, more than 478 papers were found using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. THM and LHM are two recognised approaches to the performance of a distal oesophageal myotomy in the treatment of achalasia. Of the two meta-analyses on this subject, Campos et al. [Campos GM, Vittinghoff E, Rabl C, Takata M, Gadenstätter M, Lin F, Ciovica R. Endoscopic and surgical treatments for achalasia: a systematic review and meta-analysis. Ann Surg 2009;249:45-57] illustrated improved symptom control in LHM compared with THM. Wang et al. [Wang L, Li Y, Li L, Yu C. A systematic review and meta-analysis of the Chinese literature for the treatment of achalasia. World J Gastroenterol 2008;14:5900-5906], however, observed no difference in remission rates following either approach. Close scrutiny of comparison studies revealed superiority in long-term outcomes and symptoms following LHM in three studies. There were, however, studies that illustrated comparable outcome results for THM in both resolution of dysphagia and reflux. Morbidity rates following THM were noted to be similar to or slightly higher than those following LHM in five studies, but no statistically significant difference was illustrated in these studies. Operating time and length of stay were noted to be significantly shorter in LHM when compared with THM in three studies, although there were exceptions to this, with two studies illustrating shorter or equal operating times for THM. However, LHM operating times have been shown to improve with experience gained. We conclude that there is good evidence demonstrating the effectiveness and safety of LHM, and it has come to be regarded as the gold standard treatment of achalasia. When THM is compared with LHM, the long-term results approach parity on occasion but not consistently. The overall postoperative morbidity of THM is not significantly different from that of LHM. An advantage of LHM over THM that is demonstrated is that LHM offers a shorter hospital stay and reduced operative time.

Diabetes increases apoptosis and necrosis in both ischemic and nonischemic human myocardium: role of caspases and poly-adenosine diphosphate-ribose polymerase.

OBJECTIVES: Diabetes is an important predictor of morbidity and mortality after cardiac surgery, but the reason is unclear. The aims of these studies, therefore, were to elucidate whether cell death is greater in ischemic and nonischemic diabetic human myocardium than in nondiabetic myocardium and to investigate the underlying mechanism. METHODS: The right atrial appendages (n = 8 per group) of patients without diabetes and patients with type 1 and 2 diabetes were subjected to 90 minutes of simulated ischemia and 120 minutes reoxygenation. Tissue injury was measured by the release of creatine kinase into the media, and cellular apoptosis and necrosis were assessed in tissue by the terminal transferase deoxyuridine triphosphate nick-end labeling assay and propidium iodide staining. Initiator and effector caspases activations were also measured. RESULTS: Apoptosis and necrosis were greater in the type 2 and type 1 diabetes groups than in the nondiabetes group both in fresh tissue and after simulated ischemia-reoxygenation. Activation of effector caspases was also higher in the diabetes groups than in the nondiabetes group after simulated ischemia-reoxygenation. Caspase-3 inhibition reduced apoptosis in all study groups without influencing necrosis; however, poly-adenosine diphosphate-ribose polymerase inhibition resulted in a similar reduction in apoptosis and in necrosis in all groups, whereas caspase-2 inhibition did not. CONCLUSIONS: Diabetes increases both apoptosis and necrosis in human myocardium, both fresh and after being subjected to ischemia-reoxygenation, an effect that is mediated, at least in part, by caspase-3 and poly-adenosine diphosphate-ribose polymerase activation. These results may explain the increased cardiac-related morbidity and mortality associated with cardiac surgery in patients with diabetes.

Lack of durability of surgical arterialization of coronary veins for the treatment of ischemic heart disease.

BACKGROUND AND AIM OF THE STUDY: Coronary venous arterialization with a catheter-based system has renewed interest in this therapy for the revascularization of areas that cannot be treated by conventional coronary artery bypass graft or angioplasty. However, the durability of the venous system to supply arterial pulsatile blood is still a matter of debate. METHODS: We report the outcome of four patients that underwent elective coronary artery bypass grafting of the left coronary system and in addition had selective arterialization of the posterior vein due to ungraftable poor distal vessels of the right coronary artery. Complete revascularization of the left side was achieved using the left internal mammary artery and the left radial artery. One vein graft was anastomosed to the postero-inferior vein in three cases and to two postero-inferior veins in the fourth case. RESULTS: No perioperative complications were observed and after 24 months of follow-up; all patients were angina free and without any symptoms of heart failure. The 24 months follow-up also showed (i) normal exercise test in all patients, (ii) ischemic changes in dobutamine stress echocardiography in the areas corresponding with the venous arterialization in two cases, and (iii) occlusion of the graft supplying the coronary veins in the three patients that accepted to undergo selective angiogram. CONCLUSION: In conclusion, these results indicate that arterialization of the coronary veins is not durable and that it is unlikely that this strategy is a useful technique for the revascularization of the ischemic myocardium.