Search

Summary A best evidence topic was constructed according to a structured protocol. The question addressed was whether video-assisted thoracoscopic surgery (VATS), compared to open lung resection, resulted in improved postoperative clinical outcomes, in patients with localized bronchiectasis indicated for surgery. A total of 1352 papers were found using the reported search, of which 5 papers 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. All of the identified studies were retrospective. The conversion rate from VATS to open procedure ranged from 0% to 15.3%. In comparison to thoracotomy, VATS resulted in a significant reduction of postoperative blood loss (1 study), length of hospital stay (2 studies), postoperative complication rate (2 studies), pain scales (2 studies) and chest tube duration (1 study). However, there was a significant increase in operative time (1 study) and whole cost (2 studies). There was no significant difference in the clinical recovery, which was defined by the disappearance or improvement of preoperative symptoms during the follow-up period (3 studies). We conclude that although there is limited high-level evidence, retrospective studies have suggested that VATS could significantly reduce complications rate, postoperative blood loss, pain scales, length of hospital stay and chest tube duration compared to open lung resection in selected patients with localized bronchiectasis.

Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, ‘in patients undergoing coronary artery bypass grafting is semi-skeletonized harvesting superior to pedicled harvesting of the left internal mammary artery (LIMA) in terms of conduit length, flow, rate of sternal wound infections and post-operative bleeding?’. Altogether, 235 papers were found using the reported search, of which 5 represented the best evidence to answer the clinical question. Three studies were cohort studies and 2 were randomized controlled trials. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. One randomized controlled trial showed superiority with semi-skeletonized harvesting in terms of conduit length (P

Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients undergoing valve-sparing aortic root replacement, is reimplantation superior to remodelling? The purpose of this best evidence topic was to re-review the updated evidence that has become available in the near decade since the previous review published in 2011. Altogether more than 300 papers were found using the reported search, of which 8 papers 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. The included studies have significant limitations relating to low-level evidence study design, variable outcome collection and limited significance testing with direct comparison. Long-term outcomes such as survival, recurrence of aortic regurgitation and valve reintervention were largely equal between the two procedures across the studies. This review, updated from the previous best evidence topic, continues to suggest that there are no clear recommendations or even consensus to guide clinical decision-making when choosing between remodelling or reimplantation approaches to valve-sparing aortic root replacement. To date, no study provides strong clinical benefit to favour either procedure in terms of perioperative outcomes, medium–long term survival or reintervention of the aortic valve. As such, procedure selection should be based upon patient factors and valve evaluation, combined with surgeon preference and experience.

Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘In patients undergoing coronary artery bypass grafting, is endoscopic radial artery harvesting (ERAH) superior to open radial artery harvesting in terms of postoperative complications, mortality, graft quality and patency rates?’. Altogether 130 papers were found using the reported search, of which 5 represented the best evidence to answer the clinical question. Two studies were meta-analyses and 3 were randomized trials. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In terms of graft quality, 2 randomized studies showed preserved endothelial integrity and vasoreactivity with ERAH, whereas 1 randomized study found superior endothelial function with open radial artery harvesting. Importantly, 3 studies showed graft patency was not compromised with ERAH. One meta-analysis reported no differences in graft patency between groups at 1 year [odds ratio (OR) 1.24] and up to 3–5-years follow-up (OR 1.81), as well as similar perioperative myocardial infarction rates (OR 0.80). Two meta-analyses found similar mortality in the perioperative period (OR 0.62–0.78) and up to 5 years (OR 0.64–0.67); ERAH reduced the incidence of perioperative wound complications (P-values 0.001–0.03); however, harvest times were increased with ERAH (P < 0.0005). We conclude that ERAH is non-inferior to open radial artery harvesting in terms of mortality, graft quality and patency rates, but superior in terms of reducing perioperative wound complications, with good cosmetic effect. However, these benefits come at the cost of increased harvesting time.

Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: ‘should cardiac surgery be delayed in patients with uncorrected hypothyroidism?’ A total of 1412 papers were found using the reported search, of which 7 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. There was limited high-quality evidence with the majority of the studies being retrospective. One propensity-matched analysis and 6 cohort studies provided the evidence that there was no significant difference in the rate of major adverse cardiac events including mortality based on thyroid status. However, hypothyroidism and subclinical hypothyroidism were associated with higher rates of postoperative atrial fibrillation. Based on the available evidence, we conclude that cardiac surgery should not be delayed to allow achievement of euthyroid status.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: does percutaneous transthoracic needle biopsy (PTNB) increase the risk of pleural recurrence in patients with stage I lung cancer? Altogether, 298 papers were found using the reported search, of which 7 cohort studies and 1 meta-analysis 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 were tabulated. Four cohort studies suggested an association between PTNB and pleural recurrence in patients with stage I lung cancer, while the other 3 cohort studies found that PTNB had no impact. One meta-analysis (the largest study) including 5 of the cohort studies above concluded that PTNB increased the risk of pleural recurrence among patients with stage I lung cancer with subpleural lesions. Based on the available evidence, it was suggested that there may be an association between PTNB and pleural recurrence in patients with stage I lung cancer, especially for patients with subpleural lesion.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: ‘In [patients undergoing Fontan palliation] does [fenestration] affect [early and late postoperative outcomes]?’ Altogether 509 papers were found using the reported search, of which 11 papers 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. Current data suggest that the use of fenestration has advantages in the immediate postoperative course, with fewer complications such as pleural effusions, shorter hospitalization and decreased early Fontan failure, but comparable long-term outcomes to a non-fenestrated approach. Fenestration should be used in high-risk patients or based on the haemodynamic parameters measured before weaning from cardiopulmonary bypass. Routine use may potentially lead to additional late fenestration closure procedures in some patients, without improving long-term outcomes.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether the use of 3-dimensional endoscopic vision provides superior clinical outcomes to patients undergoing video-assisted thoracic surgery for lung resection. Altogether 231 unique papers were found using the reported search, of which 6 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. Four of the 6 papers demonstrated a statistically significant reduction in operative time, although this difference may not be of sufficient magnitude to be relevant clinically. There was no difference in any other outcomes assessed. We therefore conclude that, in patients undergoing video-assisted thoracic surgery for lung resection, 3-dimensional endoscopic vision has no demonstrable impact on perioperative or oncological outcomes, or cost, although it may reduce operative time.

Summary A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether stereotactic body radiotherapy (SBRT) was equivalent to metastasectomy in patients with pulmonary oligometastases arising from solid tumours. Altogether, 1612 papers were found using the reported search, of which 5 cohort studies derived from 4 patient populations 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. All 5 studies demonstrated no significant difference in post-treatment overall survival, disease-free survival or local control between SBRT and metastasectomy for pulmonary oligometastases. One of the 5 studies showed a significantly decreased rate of severe complications among the patients treated with SBRT. The other papers reported higher rates of complications in the SBRT groups, invariably due to radiation, but with uncertain clinical significance. The evidence strength of these findings may be largely attenuated due to the small sample size, heterogeneity of SBRT protocols and incomparable follow-up periods between the 2 treatment groups. The selection criteria for the choice of treatment were not stated. We conclude, based on limited evidence, that SBRT has equivalent outcomes to metastasectomy in the treatment of patients with pulmonary oligometastases.

Summary A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether pregabalin could effectively and safely reduce postoperative pain in patients undergoing pulmonary resections. Altogether 23 papers were found using the reported search, of which 6 randomized controlled trials 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. Five of 6 randomized controlled trials demonstrated that the application of oral pregabalin during the perioperative period could effectively reduce postoperative pain after pulmonary resections without compromising patients’ safety. One randomized controlled trial reported no difference in the postoperative pain levels between the pregabalin group and the control group. The rates of adverse effects were generally found to be decreased in patients who received pregabalin compared to the patients who received routine analgesia, although 2 studies reported significantly higher incidences of mild drowsiness and dizziness among the pregabalin-treated patients. Currently available evidence supports that the perioperative administration of pregabalin can effectively and safely relieve postoperative pain for patients undergoing pulmonary resections.

Summary A best evidence topic was written according to a structured protocol. The question addressed was: in patients with inoperable early-stage primary lung cancer does microwave ablation (MWA) or stereotactic ablative body radiotherapy (SBRT) achieve improved outcomes in terms of local control, recurrence, survival and complications? Altogether, more than 550 papers were found using the reported search, of which 12 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. No single study directly compared the effects of MWA with SBRT. However, the best available evidence for MWA (7 studies) was compared to that for SBRT (5 studies). The range of 3-year survival reported for MWA was 29.2–84.7%, compared with 42.7–63.5% for SBRT. The range of median survival was 35–60 months for MWA and 32.6–48 months for SBRT. This suggests similar outcomes between these two 2 techniques. Different side-effect profiles were observed between techniques with MWA associated with pneumothorax and fever and SBRT most commonly causing radiation pneumonitis and rib fractures. The evidence base for MWA is less than that for SBRT and is heterogenous in terms of participants and technical design. However, within these limitations, we conclude that MWA appears comparable with SBRT in terms of local control and survival rates.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether low serum albumin (sAlb) was associated with postoperative bronchopleural fistula (BPF) in patients undergoing pulmonary resections. Altogether 660 papers were found using the reported search, of which 5 retrospective cohort studies 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. Four of the 5 cohort studies showed that the preoperative sAlb level in patients who experience a BPF was significantly lower than that in patients who did not experience a BPF. One of the 5 studies also reported that the incidence of BPF in patients with a lower sAlb (13.6%) was found to be significantly higher than that in patients with a higher sAlb (7.0%). The level of hypoalbuminaemia is not defined, but it may be

Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: In [patients with multivessel coronary artery diseases (CAD)] is [hybrid revascularization (HCR)] equal to [coronary artery bypass grafting (CABG)] in regard to [mortality, myocardial infarction, stroke and target vessel revascularization (TVR)]? Three-hundred and fifty-five papers were found using the reported search, of which 8 represented the best evidence to answer the question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The studies included 4 observational studies, 3 randomized controlled trials (RCTs) and 1 meta-analysis. The meta-analysis consisted of predominantly observational data with 1 randomized controlled trial and suggested non-significant differences in all major clinical outcomes. The observational studies generally cited benefit towards hybrid revascularization on the basis of equivalent major clinical outcomes rates compared to coronary artery bypass grafting, yet favourable in-hospital outcomes. One randomized controlled trial provided robust evidence of equivalent 5-year outcomes; however, the others were insufficiently powered for an effective comparison. There is a paucity of robustly designed studies to answer our clinical question effectively, given hybrid procedures are not routine in clinical practice. On the basis of mostly observational and small randomized cohorts with relatively short follow-up intervals, we conclude that current evidence suggests similar mid-term rates of major clinical outcomes after hybrid revascularization and coronary artery bypass grafting. However, without longer-term follow-up, the comparison of the two techniques, particularly relating to repeat revascularization, is still very much uncertain.

Summary A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed: Is open window thoracostomy (OWT) the only method to control infection in patients with an empyema following pulmonary resection for primary lung cancer? Altogether 442 papers were found using the reported search, of which 9 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. Empyema following anatomical lung resection (excluding pneumonectomy) is an uncommon complication but one that remains a challenge to treat effectively. Chest tube thoracostomy and intravenous antibiotics remain the initial steps to management, but evidence is lacking with regard to the best ongoing strategy. Conservative options including chest cavity irrigation, postural drainage and vacuum-assisted closure have been attempted with some success, even in the presence of a broncho-pleural fistula. However, the very limited number of patients on which these various management strategies have been trialled on prevents recommendations and clear guidance being given.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether the surgical Apgar score (SAS) was an effective assessment tool for the prediction of postoperative complications in patients undergoing oesophagectomy. In total, 7 papers were identified using the reported search, of which 6 cohort studies 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. Five of 6 cohort studies demonstrated that a low SAS was significantly associated with more postoperative complications in patients undergoing oesophagectomy. The rates of major individual complications in patients with a lower SAS were commonly higher than those in patients with a higher SAS. Two cohort studies further reported that a low SAS was significantly associated with the prolonged length of stay. The cut-off value of the SAS that had the discriminative power for patients who were considered at high morbidity risk, however, was not defined but was more likely to be 6 or less. Current available evidence suggests that the SAS system may serve as an effective assessment tool for the prediction of morbidity risk after oesophagectomy.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘In [dialysis patients undergoing a valve replacement] is [a bioprosthetic valve superior to a mechanical prosthesis] for [long-term survival and morbidity]’. Altogether more than 501 papers were found using the reported search, of which five 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. There was limited high-quality evidence with all studies being retrospective. One meta-analysis and four cohort studies provided the evidence that there was no significant difference in long-term survival based on prosthesis type. However, the majority of studies demonstrated a significantly higher rate of valve-related complications including bleeding and thromboembolism, and readmission to hospital in the mechanical valve prosthesis group, likely related to the requirement for long-term anticoagulation. We conclude that overall long-term survival in dialysis-dependent patients is poor. While prosthesis type does not play a significant contributing role to long-term survival, bioprosthetic valves were associated with significantly fewer valve-related complications. Based on the available evidence, a bioprosthetic valve may be more suitable in this high-risk group of patients as it may avoid the complications associated with long-term anticoagulation without any reduction in long-term survival.

SummaryA best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘Does concurrent use of intra-aortic balloon pump (IABP) improve survival in patients with cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO)?’. Altogether 472 papers were found using the reported search, of which 3 level 2 systematic reviews 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. The reported comparative outcomes were mortality, weaning off extracorporeal membrane oxygenation (ECMO), vascular complications and non-vascular complications. One systematic review demonstrated significantly lower in-hospital mortality with concurrent use of IABP and VA-ECMO, while the other 2 studies showed no difference in mortality. One paper reported on the weaning success from ECMO and demonstrated significantly higher weaning success with concurrent IABP usage. Another paper reported on the complications and showed no differences in vascular and non-vascular complications. We conclude that there was no significant improvement in survival with the concurrent use of IABP and VA-ECMO for a cardiogenic shock as compared to the use of VA-ECMO alone. However, the concurrent use of IABP with VA-ECMO improved weaning success from VA-ECMO. The incidence of vascular and non-vascular complications was similar with or without IABP usage.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether the administration of amiodarone is safe in patients undergoing lung resection either for prophylaxis or treatment of de novo postoperative atrial fibrillation (POAF). A total of 30 papers were identified, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date, study type, country of publication, patient demographics, relevant outcomes and results were tabulated. Among the identified papers, there were 2 meta-analyses, 1 best evidence topic and 3 randomized studies, while the remainder were retrospective. When considering perioperative amiodarone for the prophylaxis of POAF, 3 randomized studies reported no significantly increased postoperative complications or amiodarone-related side effects. Mortality and length of hospital stay were similar in patients receiving amiodarone compared with either no amiodarone or other prophylactic antiarrhythmic medication. When considering amiodarone for the treatment of POAF, 1 study reported a significantly increased incidence of ARDS after anatomical lung resection (P 0.001). Two case series reported that patients developing POAF after lung resection and managed with amiodarone also had either none or acceptable rates of side effects, with no serious respiratory complications. Two retrospective and 1 prospective observational study reported that amiodarone used either for the treatment of POAF, or for prophylaxis against it, had similar rates of postoperative respiratory complications, length of hospital stay and mortality, compared with either no treatment or treatment with other prophylactic or therapeutic agents. In accordance with the Society of Thoracic Surgeons guidelines on prophylaxis and management of POAF in general thoracic surgery, these data suggest that amiodarone is a safe agent for the management of POAF after lung resection. Careful monitoring in patients treated with amiodarone after pneumonectomy should be considered because development of acute lung toxicity can increase length of hospital stay, morbidity and mortality. Further studies may also be needed to identify the subset of pneumonectomy patients at risk of pulmonary toxicity after use of amiodarone.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: Is systematic lymph node dissection (SLND) mandatory or is sampling adequate in stage I non-small-cell lung cancer (NSCLC)? Two hundred and eleven papers were identified, of which 12 papers 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 the results of these papers are tabulated. There are 7 retrospective cohort reviews, 3 meta-analyses and 2 randomized controlled clinical trials (RCTs) to answer the clinical question. Four of the 7 retrospective studies demonstrated that the total number of resected lymph nodes and the number of lymph node stations sampled affected the accuracy of staging in patients with early-stage NSCLC and had an impact on overall survival and disease-free survival. Two RCTs, 1 meta-analysis and 1 cohort study revealed no significant benefit in overall survival and disease-free survival in patients undergoing SLND. One meta-analysis, which contained only 1 RCT, revealed significantly better 3- and 5-year survival with SLND. One further meta-analysis revealed improved survival with SLND in cohort studies but no significant difference in the 4 RCTs included. Two further studies identified specific subgroups of patients in whom LN sampling could be justified and SLND avoided. We conclude that there is no significant difference in the recurrence rate when performing either SLND or LN sampling in patients with stage I NSCLC. While retrospective cohort studies implied survival benefit with SLND, this was not borne out in RCTs and meta-analyses. However, there may be a potential survival benefit for patients who are upstaged by SLND identifying mediastinal nodal involvement.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In [patients undergoing Fontan completion], does [a younger age at operation] result in [better long-term exercise capacity and prognosis]?'. Altogether, 304 papers were found using the reported search, of which 10 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. Of these, 2 recent large reviews describe a better or a non-significant trend towards better outcomes when the Fontan procedure is performed at a younger age. This is supported by 4 studies demonstrating better long-term exercise capacity when patients undergo Fontan completion at a younger age. Additionally, 2 other studies describe increased rates of failure, adverse events and arrhythmias with older age at Fontan completion. Two publications describe non-inferior outcomes in patients with an older age at Fontan completion, although limited by the number of patients and follow-up. We conclude that the Fontan operation should be performed at an early age (7 years) because the data show higher survival and fewer adverse events, and the gradual decline in exercise capacity in Fontan patients appears accelerated when the Fontan operation is performed at older age.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the anterolateral or the inferior wall served as a better location for the 2nd arterial graft in a 3-system coronary artery bypass grafting procedure. In total, more than 1800 papers were found, of which 6 represented the best evidence to answer the clinical question. All papers demonstrated equivalent early postoperative mortality and morbidity. The 3 largest studies comparing bilateral internal thoracic arteries showed no difference in perioperative mortality and morbidity regardless of whether the 2nd internal thoracic artery was used to graft the left or right system. One of these studies, however, showed significant survival benefit for the left-sided group at 8 years, whereas another study showed a reduced patency of right internal thoracic arteries when grafted to the right coronary artery and when used in situ. One study compared radial grafts to the right- and left-sided targets and showed no difference in long-term patency. Another study also reported on the angiographic patency of right internal thoracic arteries. The authors noted a non-significant increase in graft failure when non-left anterior descending arteries were grafted but no difference between circumflex or posterior descending arteries. All studies demonstrated similar or better mid- and long-term outcomes and patency rates when using the 2nd arterial graft to revascularize left-sided targets when compared with the right. However, all outcomes were similar when comparing non-left anterior descending left-sided targets with non-right coronary artery right-sided targets. Therefore, the right coronary artery itself should probably be avoided as the 2nd arterial target.

A best evidence topic in thoracic surgery was performed according to a structured protocol. The question addressed was the role of frailty scores in predicting outcomes of patients undergoing thoracic surgery. Seventy-one papers were found using the reported search, of which three studies and one conference abstract represented the best evidence to answer the clinical question. The authors, journal date, country of publication, patient group, study type, relevant outcomes and results are tabulated. Despite an extensive literature search, few studies were identified which addressed the clinical dilemma posed, all of which were retrospective observational series. A study analysed 971 434 patients across a wide range of surgical specialties, 4648 of which were classified as thoracic. A statistically significant relationship was demonstrated between increasing frailty and higher rates of postoperative complications and mortality (P0.0001). Another study reported a similar association between modified frailty index (mFI) scores and postoperative outcomes in patients undergoing lobectomies. Morbidity increased uniformly with mFI and multivariant analysis found an mFI of0.27 (P = 0.002) to be an independent predictor of mortality. Another paper demonstrated higher rates of major postoperative complications and increased mortality (P0.001) in patients with higher preoperative dependency. A study examined geriatric frailty assessment tools for the prediction of postoperative outcomes in patients over 70 undergoing thoracic surgery for neoplasms. The Geriatric Depression Screen, Mini Mental State Examination, Fatigue Inventory, Eastern Co-Operative Oncology Group Performance Scale and Instrumental Activities of Daily Living were used as a means of determining preoperative frailty. Their conclusion supported the conclusions drawn from the larger studies that a single frailty measure alone did not predict an increase in morbidity or mortality, but in combination several measures may have a role in predicting postoperative outcomes. The clinical bottom line is that there is a paucity of evidence to either fully support or fully refute the use of preoperative frailty scoring as a reliable means of predicting morbidity and mortality in thoracic surgery. The evidence presented does however indicate the potentially important clinical role that frailty scores may have in the future.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: Does repeat thymectomy improve symptoms in patients with refractory myasthenia gravis after thymectomy? A total of 189 papers were found using the reported search, of which seven represented the best evidence to answer the clinical question. The outcome measures included operative mortality and morbidity, as well as long-term remission rate. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All the studies were small (4–21 patients), retrospective, single institutional case series. There was considerable heterogeneity in the studies. The interval between the first and second operation ranged from less than a year to over 10 years. The operative approach of the initial operation included transcervical, trans-sternal and substernal approaches. The maximal medical therapy received by the patients prior to reoperation varied from anticholinesterase alone to cytotoxic therapy and regular plasmapheresis. The severity of symptoms ranged from Osserman Class IIa to V. The operative approach to re-thymectomy included resternotomy, thoracoscopy and a combination of both. There was no perioperative mortality. One study reported injury to the innominate vein at resternotomy in 3 (14.3%) patients. One study reported myasthenic crisis in 2 patients in the postoperative period. Only one study reported complete remission in 2 patients. In general, however, 52–95% of patients reported some improvement. There was no consistent, objective measure of improvement in these studies. We conclude that repeat thymectomy for patients with refractory myasthenia gravis after previous thymectomy is safe especially for patients whose first procedure was transcervical. Complete remissions are rare but, in these small series, 60–70% of patients report improvement. Clinical improvement appears to be associated with the presence of residual thymic tissue at the second operation, but these cannot be reliably identified on preoperative imaging. Patient selection remains driven by symptoms.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in patients undergoing primary cardiac surgery, does routine preoperative computed tomography (CT) imaging provide clinical benefit as measured by either a decrease in complications or a change in surgical approach. Altogether, 125 papers were found using the reported search, of which 5 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. All 5 studies reviewed reported change in operative strategy as a result of preoperative imaging, with the most common change being an alternative cannulation site. Two comparative studies reported decreased mortality and decreased perioperative stroke in patients who undergo preoperative CT, when compared to patients who do not. However, the results from these 2 studies are difficult to interpret as they used different imaging modalities and different patient populations. One study selected high-risk patients for preoperative CT, rather than routine use, but the findings were similar. We conclude that preoperative CT, whether non-contrast CT or CT angiography, can help optimize operative strategy and decrease postoperative stroke rate and mortality after primary cardiac surgery.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether endobronchial valves improve outcomes in patients with severe emphysema. Eighty-seven papers were found using the reported search, of which seven 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. Endobronchial Valve for Emphysema Palliation Trial demonstrated that endobronchial valve increased forced expiratory volume in one second by 4.3% (95% confidence interval 1.4–7.2) and decreased by 2.5% in the control group (95% confidence interval −5.4 to 0.4) at a 6-month interval. This benefit is more marked in patients who do not have collateral ventilation into the area of lung being isolated as mapped by bronchoscopic physiological mapping (Chartis) or by computed tomography imaging documenting intact fissures. This evidence is reflected in the Endobronchial Valve for Emphysema Palliation Trial. Patients treated with endobronchial valve with high heterogeneity and complete fissures had greater improvement in forced expiratory volume in one second at 6- and 12-month intervals. We conclude that endobronchial valve placement improves lung function, exercise capacity and quality of life in selected patients with emphysematous diseases.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest (DHCA)? Altogether more than 34 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question, 5 of which were animal studies, 1 was a theoretical laboratory study and 1 study looked at the ability to cool using circulating water ‘jackets’ in humans. There were no available human studies looking at the neurological outcome with or without topical head cooling with ice without further adjunct methods of cerebral protection. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four papers studied animals undergoing DHCA for 45 min–2 h depending on the study design, with or without packing the head with ice. The studies all demonstrated improved cerebral cooling when the head was packed with ice during DHCA. They also illustrated an improved neurological outcome, with better behavioural scores (P

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients with carcinoid syndrome undergoing valve replacement, will a biological valve have acceptable durability?' Altogether, more than 130 papers were found using the reported search, of which 17 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. The pooled data from all papers represent 51 patients with carcinoid right heart disease who underwent tricuspid valve replacement. Two 'outcomes' studies reported a 30-day postoperative mortality of 16.7-18% and 2-year survival rates of 44 and 50%, respectively. Seventeen patients were detailed in case reports. Of these 17 patients, 7 died during the follow-up period. All but one of these patients had a normal bioprosthesis at echocardiography or at post-mortem. One patient with a plaque-covered valve had a functionally normal valve. We conclude that at present, the best available evidence suggests that although 30-day mortality approaches 20%, approximately half of patients with carcinoid syndrome undergoing tricuspid valve replacement can be expected to survive 2 years. Some patients survive considerably longer than this, beyond 10 years in some cases. Importantly, at autopsy, many replacement valves have been shown to be normal, with a few patients reported as having died of cardiac causes. This should be taken as cautious evidence that biological valves have an acceptable lifespan in patients with carcinoid syndrome and that the process of valve destruction seen in carcinoid patients does not continue to a significant level in the bioprosthesis. Caveats to this include the lack of any directly comparative trial and the predominance of case reports as opposed to higher-level evidence.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients undergoing video-assisted thoracoscopic surgery (VATS) excision, what is the best way to locate a subcentimetre solitary pulmonary nodule (PN) in order to achieve successful excision?' Altogether, 107 papers were found using the reported search, of which 19 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 were tabulated. The hook-wire technique showed a varied success rate ranging from 58 to 97.6% and a relatively higher failure rate due to wire dislodgement. The most common complication of this method was pneumothorax. CT-guided spiral-wire localization displayed a success rate of 86% with the added advantage of providing more stability than the hook-wire technique and permitting manipulation. Radio-guided localization techniques and fluoroscopic-aided methods using contrast media displayed consistently high sensitivities with few complications. The radio-guided technique had the benefit of allowing a longer time-period between the staining of the nodule and the operation. Ultrasonography showed sensitivities ranging from 92.6 to 100%; however, it is highly operator-dependent. Finger palpation was shown to achieve suboptimal results and should be avoided. We concluded that radio-guided surgery is a preferable method. It showed high accuracy with minimal complications and operator dependence in detecting subcentimetre PNs when compared with other techniques such as ultrasonography, finger palpation, fluoroscopic, hook-wire, spiral-wire and microcoil localization.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: In patients undergoing off-pump coronary artery bypass (OPCAB) surgery, does the off-pump to on-pump conversion rate have an impact on post-operative results? Altogether more than 420 papers were found using the reported search, of which 14 randomized controlled trials (RCTs) 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 and ordered according to the sample size. In the 14 RCTs reviewed, the off-pump to on-pump conversion rate incidence ranged from 0 to 13.3%. The most frequent causes of conversion were haemodynamic instability and intramyocardial-coronary target. A low conversion rate (9%), and among them, one reported lower morbidity of the OPCAB patients, three were not able to show any benefit in terms of morbidity of the OPCAB, and one reported worse survival and patency graft rate of the OPCAB group. Four RCTs reported conversion rates ranging from 3.7 to 7.0%, describing a wide spectrum of results. We conclude that RCTs with a high off-pump to on-pump conversion rate were often associated with a lower experience in OPCAB of the surgeons participating in the trials. These studies were also mostly unable to show any benefit in terms of mortality or morbidity of OPCAB over the on-pump strategy. On the contrary, a low conversion rate is mostly reported by RCTs with a high structured experience in OPCAB. These trials were mostly able to show a benefit, in terms of morbidity and survival, of the OPCAB over the on-pump strategy.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in patients undergoing a surgery for endocarditis is a biological valve or mechanical valve superior for achieving long-term low rates of reinfection?' Altogether more than 41 papers were found using the reported search, of which nine 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. Out of the studies that include statistical comparisons, in mechanical valve replacement the average endocarditis recurrence rate ranged from approximately 3 to 9% and in biological valves from approximately 7 to 29%. Out of the studies that specifically compared the outcomes of the two valves, 50% concluded there to be no significant difference when separated from other risk factors and 50% recommended a mechanical valve for lower recurrence and higher survival rates. The Euro Heart Survey found that 63% of valve replacements were mechanical, due to young age (90%) and physician preference (75%) and only 21% bioprosthetic. Current guidelines from American College of Cardiology/American Heart Association (ACC/AHA) recommend a mechanical valve in patients65 years old and a bioprosthetic valve if65, without risk factors for thromboembolism, but this is based on class II evidence (conflicting evidence or opinion). These guidelines are not specific to patients with infective endocarditis, so it is vital to review the literature related to this. Three of the studies in the search specify that for patients under 60-65 years old, a mechanical valve has greater benefit, but this was not found to be true for the over 65 years. It can be concluded that for patients under 65 years old, a mechanical valve may offer greater freedom from reoperation and increased long-term survival when compared to a bioprosthetic valve (assuming no other co-morbidities), although this divide is narrowing with the use of newer generation bioprosthetic valves and has to be off-set against potential bleeding risks. For patients over 65 years, other important variants need to be considered including patient choice, correct protocols of antibiotics and radical debridement.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was if transit-time flow measurement (TTFM) can improve graft patency and clinical outcome in patients undergoing coronary surgery. Altogether 102 papers were found using the reported search, of which 10 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. The papers considered for the analysis focus attention on three major topics: intraoperative graft verification with the aim of improving immediate graft patency; predictive power of early- and mid-term graft patency and clinical outcome. Among TTFM parameters, according to different authors, mean graft flow is set at 10 or 15 ml/min; pulsatility index is set at three or five; insufficiency ratio is set by 3 or 4%. We conclude that TTFM is a reliable method to verify intraoperative graft patency. There is some evidence that checking graft patency intraoperatively may improve mid-term outcomes.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients with severe active aortic valve endocarditis, is a stentless valve as good as a homograft?' The scientific literature was reviewed by searching Medline, using the OVID interface, from 1950 to March 2010. One hundred and eight papers were found. Twelve papers were used in the writing of the article, of which 10 were deemed relevant to the topic. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes, and results of these papers were tabulated. In the homograft series, literature review reports a reinfection rate from 3.8% to 6.8%. Yankah, in studying 161 patients with endocarditis, reports 91% freedom from reinfection at 10 and 17 years and 70% survival at 17-year follow-up. Sabik, in studying 103 consecutive patients with prosthetic endocarditis, reports a 3.8% reinfection rate and 95% freedom from reinfection at 10 years, with 56% survival at 10 year. In the stentless series: Musci, in studying 255 patients with endocarditis, reports a 8.6% reinfection rate, 83% freedom from reinfection at five years and 46% five-year survival. He finds a non-significant difference between survival and freedom from reinfection in patients with native valve endocarditis compared to those with prosthetic valve endocarditis (PVE) (P=0.1371 and P=0.8356). The same author, in 221 patients treated with a homograft, reports a 5.4% reinfection rate and 10-year freedom from reoperation, with a reinfection rate in native and PVE of 92%. Ten-year survival was better in native than in PVE (P=0.029). Siniawski, comparing two groups of patients treated with stentless valves and homografts, finds an equal reinfection rate of 4% and lower mortality for the stentless group (12% vs. 16%, respectively). He finds the reinfection rate to be lower for the homograft and stentless groups than for the patients treated with standard prostheses, respectively, 5.8%, 3.7% and 33%. The stentless valve offers a reinfection rate and postoperative echocardiographic data comparable to those achieved with homografts. Further follow-up is required to determine the stentless valve durability and long-term freedom from valve-related complications.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Should you place one or two chest drains in patients undergoing lobectomy?' Altogether200 papers were found using the reported search, of which six 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 the insertion of one chest drain confers less postoperative pain as shown by one randomised controlled trial (RCT) and one further cohort study. In addition, another RCT was able to demonstrate a lower use of non-standard analgesia in the face of no overall difference in total pain score while another RCT conveyed a significantly shorter duration of opioid and NSAID use inferring less postoperative pain. From all the studies in this area, no differences in the duration and amount of drainage or the length of hospital stay could be demonstrated with any significance. Therefore, the use of the conventional two drain method is not superior to the one drain method and may indeed cause more pain and is obviously more expensive.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In patients with sewing needle cardiac injuries is the surgical approach the recommended treatment?' The scientific literature was reviewed by searching Medline, using Ovid interface, from 1950 to August 2009. Six hundred and twenty-six papers were found, of which 24 were deemed relevant to this topic. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. The cause of injury may delay the timing of presentation the diagnosis and consequently the therapeutic strategy. In nearly all the cases in the reviewed papers the authors surgically removed the needle from the heart. However, out of the 24 papers, four patients had a conservative treatment. Most of the authors recommend early removal of the needle to prevent migration and further anatomical damage. The early surgical removal of foreign bodies in the heart is considered an effective approach to prevent complications. The heart is more vulnerable to serious injuries when the foreign body is extracardiac than when the foreign body is completely intracardiac. The unceasing motion of the heart against the sharp point of the fixed foreign body will result in repetitive wounding with bleeding and consequent cardiac tamponade. Due to the tendency of the needle to migrate, the preoperative use of computer tomography scan, trans-thoracic and trans-oesophageal echocardiography have been advocated to locate the exact position of the needle and its correlation with the surrounding tissues. The intraoperative use of epicardial ultrasound or fluoroscopy is also recommended. However, in cases of late diagnosis, in previously untreated patients, treatment can be individualized. If the symptoms are less severe it is reasonable to adopt a conservative approach as with time most foreign bodies become safely encysted and do no harm. Patients can remain asymptomatic for many years. However, they may present many years later with complications such as pericarditis, tamponade or endocarditis. Strict follow-up is useful in those patients.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed whether video-assisted thoracoscopic surgery (VATS) was justifiable for first-episode primary spontaneous pneumothorax (PSP). Altogether 183 papers were found using the reported search, of which nine 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 VATS has superior outcomes in terms of recurrence rates of pneumothorax (from 0 to 13% according to several studies for VATS vs. 22.8 to 42% for tube thoracostomy alone), duration of chest tube drainage (CTD) (4.56 vs.7.6 days) and mean hospital stay (from 2.4 to 7.8 days vs. 6 to 12 days for CTD) with first-episode PSP compared with conservative treatment. Additionally, even if VATS is associated with an average increased cost of $408, this is mitigated by the reduced length of stay and decreased pneumothorax recurrence, both resulting in a reduction of cost of 42% compared to conservative approach. These findings were not replicated in an article considering primary VATS (PV) vs. secondary VATS (SV) as the best treatment modality for PSP in children. Although the total treatment length of stay was significantly shorter for PV vs. SV (7.1+/-0.96 vs. 10.5+/-1.2, P=0.04), morbidity from recurrent pneumothorax after VATS occurred more frequently after PV than SV (4/14 vs. 0/20, P0.05). In this article the observed recurrence rate was 54%. Performing PV on all patients with PSP would increase cost by $4010 per patient and require a recurrence rate of 72% or more to financially justify this approach, therefore, the increased morbidity and cost do not justify a strategy of PV blebectomy/pleurodesis in children with spontaneous pneumothorax (SP). Instead, secondary treatment is recommended. Lastly, two articles also examined the rate of recurrence of VATS compared to open thoracotomy (OT). The range was from 0 to 7.7% for OT vs. 10.3 to 13% for VATS, a non-statistical difference.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: does intermittent cross-clamp fibrillation provide equivalent myocardial protection compared to cardioplegia in patients undergoing bypass graft revascularisation? Altogether, 58 papers were found using the reported search, of which 13 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 identified 13 studies, of which eight were randomised prospective trials. None of these studies found increased mortality, seven analyzed serum cardiac enzymes and showed that intermittent ischemic arrest provides equal or better protection compared to cardioplegic techniques. Two studies found an increased usage of inotropes and intra aortic balloon pump (IABP) in the intermittent ischemic arrest group. We conclude that intermittent cross-clamp fibrillation is a versatile and cost-effective method of myocardial protection, with the immediate postoperative outcome comparable to cardioplegic arrest in first-time coronary artery bypass graft (CABG). The ischaemic duration associated with intermittent cross-clamp fibrillation is invariably shorter than that associated with cardioplegic arrest, and this may be one explanation for the comparable outcomes. There may also be an element of preconditioning protection during the intermittent cross-clamp fibrillation method, as has been shown experimentally. During elective CABG in patients with no clinical evidence of aortic or cerebro-vascular disease, the incidence of peri-operative microemboli (ME) and postoperative neuropsychological disturbances are shown to be comparable with both techniques of myocardial preservation.

A best evidence topic in cardio thoracic surgery was written according to a structured protocol. The question addressed whether cardiac re-transplantation can be performed with an acceptable survival in patients who suffer primary graft failure? Altogether 458 papers were found using the reported search, of which 18 presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. We conclude that while re-transplantation for graft coronary disease has a similar survival to patients undergoing primary transplantation, acute graft failure or rejection should be treated with a mechanical assist device, as acute re-transplantation is associated with an unacceptably high mortality.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether an early invasive approach (involving early coronary angiography followed by revascularisation if suitable) is superior to a conservative approach (with revascularisation only in patients with failed medical therapy) in patients with acute coronary syndrome. Altogether 282 papers were found using the reported search, of which seven presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that in patients diagnosed with acute coronary syndrome, an early invasive approach is clearly superior to a conservative approach.

A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether, in patients with persistent type 2 endoleak (T2EL) post-endovascular abdominal aortic aneurysm repair (EVAR), intervention is associated with better outcomes than observation. Four hundred and eighty-three papers were found using the reported search, of which 12 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. In a recently published systematic review including 21 744 patients who underwent EVAR, 35.4% of T2ELs resolved spontaneously, 28.5% of secondary interventions were unsuccessful and rupture occurred in only 0.9% of patients with isolated T2EL. Spontaneous sealing in 62-75% of T2ELs were reported by two included studies. A failure rate of 80% associated with transarterial embolization in aggressive treatment of any T2EL was reported by one study. Conversely, another study reported a clinical success rate of 80% associated with the transarterial approach. One study reported that of patients who underwent embolization of a persistent T2EL, 37.9% continued to experience sac growth and 20% had recurrent endoleak at 5 years. One study demonstrated that the transealing procedure for T2EL had a technical success rate of 94.1%. We conclude that the available evidence with regard to management of persistent T2EL is mainly based on retrospective case series. Conflicting results from heterogeneous studies, however, failed to support an optimal threshold for intervention. Considering the reported relatively benign natural course of most T2ELs and the fact that most T2ELs seal spontaneously, conservative management of persistent T2EL in the absence of sac expansion might be appropriate. Where intervention is indicated, imaging should exclude occult type I and III leaks as ∼25% are not simple T2EL. Translumbar embolization of T2EL is associated with higher success rates than transarterial. Following a successful intervention, continued long-term surveillance is necessary due to the high risk (25-80%) of recurrence. The current evidence indicates that aneurysmal rupture due to an isolated T2EL is rare. Long-term prospective studies may provide better evidence to define the optimal threshold for intervention.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether high doses of protamine causes increased bleeding in patients post cardiac surgery. Altogether 268 papers were found using the reported search, of which five presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that high doses of protamine can cause increased bleeding and impaired platelet function but these effects have never been demonstrated below a ratio of 2.6:1 protamine to heparin.

A best evidence topic was constructed according to a structured protocol. The question addressed was whether surgical stabilization is effective in improving the outcomes of patients with isolated multiple distracted and painful non-flail rib fractures. Of the 356 papers found using a report search, nine presented the best evidence to answer the clinical question. The authors, journal, date and country of publication, study type, group studied, relevant outcomes and results of these papers are given. We conclude that, on the whole, the nine retrieved studies clearly support the use of surgical stabilization in the management of isolated multiple non-flail and painful rib fractures for improving patient outcomes. The interest and benefit was shown not only in terms of pain (McGill pain questionnaire) and respiratory function (forced vital capacity, forced expiratory volume in 1 s and carbon monoxide diffusing capacity), but also in improved quality of life (RAND 36-Item Health Survey) and reduced socio-professional disability. Indeed, most of the authors justified surgical management based on the fact that the results of surgical stabilization showed improvement in short- and long-term patient outcomes, with fast reduction in pain and disability, as well as lower average wait before recommencing normal activities. Hence, the current evidence shows surgical stabilization to be safe and effective in alleviating post-operative pain and in improving patient recovery, thus enhancing the outcome after isolated multiple rib fractures. However, given the little published evidence, prospective trials are necessary to confirm these encouraging results.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients with concomitant aortic and mitral valve disease is aortic valve replacement with mitral valve plasty (MVP) superior to double valve replacement (DVR) in terms of improved long-term survival? Altogether 156 papers were found using the reported search, of which seven 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. Out of seven papers, that simultaneously compare these two treatment modalities, three favor MVP combined with aortic valve replacement (AVR) over DVR, two papers advocate the opposite and two failed to find any significant difference in long-term survival, freedom from reoperation and thromboembolic and bleeding complications between these two surgical options. All data presented derive from level 2b evidence. Critical appraisal of these studies is constricted by the large heterogeneity of the patients, diversity in treatment protocols and inherent selection bias. We conclude that currently the available evidence is insufficient to prove that AVR with MVP is superior to DVR in patients with double valve disease.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether pH-stat or alpha-stat is the best technique to follow in patients undergoing deep hypothermic circulatory arrest. Altogether 206 papers were found using the reported search, of which 16 represent 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. Excluding one paper which provided inconclusive results, six studies found better cerebrovascular metabolism with alpha-stat while three studies found better cerebrovascular metabolism with pH-stat. Four other studies showed no significant difference in the cerebrovascular metabolism between the two acid-base management strategies in patients undergoing deep hypothermic circulatory arrest. Nine studies compared the neuropsychological outcome in patients who underwent deep hypothermic circulatory arrest with three studies supporting each alternative conclusion of preference towards alpha-stat or pH-stat management. The remaining three studies showed no significant difference between the two groups of acid-base management. Comparing the 16 studies based on the age of the patients studied, three out of the four papers which demonstrated that the pH-stat method is a better strategy to improve intraoperative and postoperative outcome were based on a sample of paediatric patients. Conversely, all seven papers that suggested alpha-stat method is associated with better intraoperative and postoperative outcome were based on studies done on adult patients. The remaining four papers suggested no significant difference between the pH-stat group and alpha-stat group. In conclusion, there is evidence to suggest that the best technique to follow in the management of acid-base in patients undergoing deep hypothermic circulatory arrest during cardiac surgery is dependent upon the age of the patient with better results using pH-stat in the paediatric patient and alpha-stat in the adult patient.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether abdominal cardiopulmonary resuscitation (CPR) could be used instead of external cardiac massage either to protect the recent sternotomy or while chest compressions are not possible whilst a sternotomy is being performed. Altogether 386 papers were found using the reported search, of which 10 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. Patients who arrest after cardiac surgery and require chest reopening will have a period of no external chest compression and therefore, no cerebral or coronary perfusion. In addition, if a patient arrests prior to cardiac surgery there will be a period of time performing the sternotomy during which there will be no external compressions. We found only one paper in a porcine model that looked at the effectiveness of abdominal only CPR although it did show that abdominal CPR was actually 60% better than chest CPR. Interposed abdominal and chest compressions has been much more extensively studied and has been shown to be significantly better in return of spontaneous circulation than chest compressions alone. We conclude that currently there is very little evidence to support abdominal only CPR although these studies may support the concept that it may potentially increase the coronary and cerebral perfusion pressure.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether treatment with magnesium in addition to an anti-arrhythmic is beneficial to patients who have gone into atrial fibrillation after cardiac surgery. Altogether 466 papers were identified using the below mentioned search, of which 8 papers presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group, relevant outcomes and weaknesses were tabulated. We conclude that while the literature on magnesium prophylaxis and non-cardiac surgical studies on magnesium therapy for atrial fibrillation suggest that magnesium may be of benefit, there are currently no studies in post-cardiac surgery atrial fibrillation to support the use of magnesium therapy for these patients.

A best evidence topic in cardiovascular surgery was written according to a structured protocol. The question addressed was whether asymptomatic significant carotid artery stenosis (ASCAS) warrants carotid endarterectomy (CEA) in patients undergoing cardiac surgery. 128 Papers were found using the reported search, of these 10 presented represent the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that low risk, younger patients with a significant asymptomatic carotid artery stenosis should be considered for carotid endarterectomy at some stage. There is, however, no strong evidence that this must be performed prior to, or during CABG.

Summary A best evidence topic was written according to a structured protocol. The question addressed was: In patients with mesothelioma who develop a local recurrence after macroscopic complete resection (MCR) surgery, does performing a second radical surgery lead to improvement in survival? A total of 2076 papers were identified using the reported search, of which 3 represented the best evidence to answer the clinical question. The authors, date, journal, country, study type, population, outcomes and key results are tabulated. The 2 largest studies included 16 patients each who underwent a second surgery for radical resection of recurrence after MCR for mesothelioma. One study (with 16 chest wall resections) had no in-hospital mortality, whereas the other study showed 2/16 (12.5%) patients dying in the hospital, both of whom had a contralateral pleurectomy. One study correlated the median survival after the second surgery with the time to recurrence and epithelioid pathology. The other study showed better post-recurrence survival after a second surgery, with patients having a significantly longer median post-recurrence survival (16 months) compared with those who received other types of second-line therapy (9 months) and those who received no therapy at all (2 months) (P

A best evidence topic was written according to a structured protocol. The question addressed was whether patients undergoing coronary bypass grafting and mitral intervention for moderate to severe ischaemic mitral regurgitation are best treated with mitral repair or replacement. Five hundred and fifty papers were found using the reported search. Based on the 14 non-randomised studies judged to represent best evidence, we concluded that whilst there is some evidence that the operative mortality may be less following mitral valve repair, long-term data are equivocal. Even with contemporary techniques, recurrent mitral regurgitation is not uncommon following repair. Replacement was more frequently performed for patients with greater co-morbidity. Whilst two studies attempted to control for this using propensity analysis, in the majority of studies this introduced considerable bias. No data was available on long-term functional outcomes and quality of life. As there is currently insufficient evidence to inform clinical practice, a randomised trial is warranted in this important area.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether it is worth performing surgical ventricular restoration (SVR) in patients with ischemic cardiomyopathy and akinetic but non-aneurysmal segments in the left ventricle. Altogether 237 papers were identified using the below mentioned search. Fifteen presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group, relevant outcomes and weaknesses were tabulated. The RESTORE group and others have demonstrated that in patients with ischaemic cardiomyopathy and an akinetic anterior ventricular wall, significant improvements in survival and symptoms can be obtained with an acceptable operative risk. Improvements in EF of 10-15% have been consistently demonstrated with significant improvements in symptoms also. The RESTORE group peri-operative mortality was 5.3%. Currently, 25% of US centres participating in the National Cardiac Database have performed at least one SVR procedure, although most only perform low numbers. In this database over 2 years from 2002, there were 731 procedures. The mortality was 9.4% and 33% of patients suffered a major complication or death, cautioning that in the 'real-world' results may not be as good as those from high volume tertiary referral centres. Patient selection may be a reason for these differences. The STICH trial has now completed the recruitment of 2136 patients into a randomised trial of medical therapy vs. coronary artery bypass grafting (CABG) vs. CABG and SVR surgery. With first results expected in 2009, this study will be a landmark in providing the evidence base for the selection of patients for surgical ventricular restoration surgery.

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether the intraoperative use of surgical adhesives in patients undergoing lung resection would reduce the incidence and length of postoperative air leaks. The reported search strategy identified 261 papers of which 12 were considered to represent the best evidence available. The author, journal, publication date, patient groups studied, study types, relevant outcomes, results and study weaknesses were tabulated. We conclude that six of the identified randomised trials found a significant reduction in air leak duration, but five found no significant difference. In contrast to significant reductions in air leak, only two studies identified a reduction in time to chest drain removal. Also, only two studies found a significant reduction in length of stay. There are multiple issues surrounding these studies ranging from identifying the optimal glue and delivery system, dealing with the learning curve of surgeons and robust protocols for chest drain removal to selection of patients suitable for surgical adhesive usage. Thus, routine usage of surgical adhesive for all operations cannot yet be recommended, although there is a wide range of adhesives available to surgeons which may be useful in selected situations.