Does off-pump coronary revascularization reduce mortality in re-operative coronary artery surgery? A meta-analysis of observational studies

BACKGROUND

Re-operative coronary artery bypass grafting (CABG) is a challenging operation that is often performed in a high-risk patient group. Avoiding cardiopulmonary bypass (CPB) in these patients is hypothesised to be advantageous due to the reduced invasiveness and physiological stress of off-pump coronary artery bypass grafting (OPCAB). The aims of this study were to assess whether OPCAB may improve outcomes in patients undergoing re-operative CABG.

METHODS

Twelve studies, incorporating 3471 patients, were identified by systematic literature review. These were meta-analysed using random-effects modelling. Primary endpoints were 30-day and mid-term mortality. Secondary endpoints were completeness of revascularization, mean number of grafts per patient and the effect of intra-operative conversion on mortality.

RESULTS

A significantly lower rate of 30-day mortality was observed with OPCAB (OR 0.51, 95% CI [0.35, 0.74]), however, no difference was demonstrated in mid-term mortality. Significantly less complete revascularization and mean number of grafts per patient were observed in the OPCAB group. Meta-regression revealed no change in 30-day mortality when the effect of conversion from one technique to the other was assessed.

CONCLUSIONS

Off-pump techniques may reduce early mortality in selected patients undergoing re-operative CABG; however, this does not persist into mid-term follow-up. OPCAB may also lead to intra-operative conversion and, although this did not affect outcomes in this study, these results are constrained by the limited data available. Furthermore, OPCAB may increase target vessel revascularization and, consequently, incomplete revascularization which, whilst not reflected in the short-term outcomes, requires longer-term follow-up in order to be fully assessed.

Safety of training and assessment in operating theatres--a systematic review and meta-analysis

OBJECTIVE

Procedural outcomes can be used to assess the performance of specialists and trainees. This article establishes a systematic evidence base for the safety of training in the operating theatre. It also explores the possibility of using early, intermediate and late procedural outcomes of cardiac surgical operations to evaluate the performance of the clinicians and the healthcare system.

METHODS

Medline, EMBASE and PsycINFO databases were searched. Comparative studies evaluating quality indicators of cardiac surgical procedures (coronary artery bypass grafting (CABG) and valve surgery) were included. guidelines from the preferred reporting items for systematic reviews and meta-analyses (PRISMA) were used.

RESULTS

Fourteen studies met the inclusion criteria. For CABG, meta-analysis of outcomes did not show any significant differences between the technical and non-technical skills of trainees versus specialists apart from bypass time (less for specialists) and intensive care unit (ICU) length of stay (less for trainees). Studies reporting outcomes on valve surgery also did not report any statistically significant differences amongst the outcomes.

CONCLUSION

This systematic review did not discern any significant differences between the procedural outcomes of trainees and specialists, which indicates that trainees are safe to operate under senior supervision. In addition, this article recommends that various procedural outcomes can be used to evaluate the performance of clinicians and healthcare systems. Prospective studies need to be performed, taking into account the specific contribution of trainees and specialists during the procedure. This will give a clearer indication of safety and performance of trainees and specialists in the operating theatre.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Metabolic surgery: an evolution through bariatric animal models

Metabolic surgery was developed through the application and experience gained from bariatric or weight loss procedures. Much of our knowledge from the procedures comes from the study of animal models, where they have revealed anatomic feasibility, systemic physiological elements and cellular metabolic effects. The first generation of operation included the jejunoileal bypass and partial ileal bypass that led to the development of the current procedures including Roux-en-Y gastric bypass, biliopancreatic diversion, adjustable gastric banding and sleeve gastrectomy. These operations carry significant metabolic benefits and can reduce the risk of diabetes, heart disease and cancer. Further insights from these animal models can reveal genetic, molecular and systemic effects that can enhance and develop the next generation of metabolic operations.

Diabetes resolution and hyperinsulinaemia after metabolic Roux-en-Y gastric bypass

The global prevalence of type 2 diabetes mellitus and impaired glucose metabolism continues to rise in conjunction with the pandemic of obesity. The metabolic Roux-en-Y gastric bypass operation offers the successful resolution of diabetes in addition to sustained weight loss and excellent long-term outcomes in morbidly obese individuals. The procedure consists of the physiological BRAVE effects: (i) Bile flow alteration; (ii) Reduction of gastric size; (iii) Anatomical gut rearrangement and altered flow of nutrients; (iv) Vagal manipulation and (v) Enteric gut hormone modulation. This operation provides anti-diabetic effects through decreasing insulin resistance and increasing the efficiency of insulin secretion. These metabolic outcomes are achieved through weight-independent and weight-dependent mechanisms. These include the foregut, midgut and hindgut mechanisms, decreased inflammation, fat, adipokine and bile metabolism, metabolic modulation, shifts in gut microbial composition and intestinal gluconeogenesis. In a small minority of patients, gastric bypass results in hyperinsulinaemic hypoglycaemia that may lead to nesidioblastosis (pancreatic beta-cell hypertrophy with islet hyperplasia). Elucidating the precise metabolic mechanisms of diabetes resolution and hyperinsulinaemia after surgery can lead to improved operations and disease-specific procedures including 'diabetes surgery'. It can also improve our understanding of diabetes pathogenesis that may provide novel strategies for the management of metabolic syndrome and impaired glucose metabolism.

Pulmonary homograft endocarditis 19 years after a Ross procedure

We report the case of a patient with acute pulmonary homograft endocarditis secondary to Streptococcus agalactiae from a cat-bite. He had undergone a Ross procedure nineteen years earlier. In view of unremitting infection with large pulmonary trunk and right pulmonary artery vegetations, the patient underwent successful pulmonary vegetectomy and homograft replacement.

Antimicrobial prophylaxis for endocarditis: emotion or science?

Yet another guideline on the prevention of infective endocarditis has been published, this time limiting prophylaxis to high-risk patients.

William Penny Brookes (1809-1895): forgotten Olympic Lord of the Rings

The contribution of Dr William Penny Brookes (1809-1895) to the Olympic Games is scarcely reported in the medical literature. Presented here is a brief report of his life and work. Furthermore, the need to promote public health and fitness through the Olympics is re-emphasised.

Sensitizing the insensitive

Lithium is still the treatment of choice in bipolar affective disorder. The patient presented here represents an example of the possible severity of metabolic defects resulting from lithium use. In this case, it caused severe intractable nephrogenic diabetes insipidus (NDI). Our case report draws attention to 2 important messages. The first is the complexity in treating psychiatric patients that is often not borne out in the medical literature. The second is the role and power of pharmacological augmentation. While the role of these agents has been appreciated for some time, the use of carbamazepine and of drug combinations is not as well recognized. We emphasize the clinical features of NDI, lithium's metabolic sequelae and furthermore collate the most up-to-date account of the signalling effects conferred by these agents in a summary diagram.