Obesity--a risk factor for postoperative complications in general surgery?

BACKGROUND: Obesity is generally believed to be a risk factor for the development of postoperative complications. Although being obese is associated with medical hazards, recent literature shows no convincing data to support this assumption. Moreover a paradox between body mass index and survival is described. This study was designed to determine influence of body mass index on postoperative complications and long-term survival after surgery. METHODS: A single-centre prospective analysis of postoperative complications in 4293 patients undergoing general surgery was conducted, with a median follow-up time of 6.3 years. We analyzed the impact of bodyweight on postoperative morbidity and mortality, using univariate and multivariate regression models. RESULTS: The obese had more concomitant diseases, increased risk of wound infection, greater intraoperative blood loss and a longer operation time. Being underweight was associated with a higher risk of complications, although not significant in adjusted analysis. Multivariate regression analysis demonstrated that underweight patients had worse outcome (HR 2.1; 95 % CI 1.4-3.0), whereas being overweight (HR 0.6; 95 % CI 0.5-0.8) or obese (HR 0.7; 95 % CI 0.6-0.9) was associated with improved survival. CONCLUSION: Obesity alone is a significant risk factor for wound infection, more surgical blood loss and a longer operation time. Being obese is associated with improved long-term survival, validating the obesity paradox. We also found that complication and mortality rates are significantly worse for underweight patients. Our findings suggest that a tendency to regard obesity as a major risk factor in general surgery is not justified. It is the underweight patient who is most at risk of major postoperative complications, including long-term mortality.

Type 2 diabetes mellitus, independent of insulin use, is associated with an increased risk of cardiac complications after vascular surgery.

Previous reports on the prognostic value of diabetes mellitus for cardiac complications after vascular surgery show divergent results, especially in regards to the role of type 2 diabetes as a cardiac risk factor, which remains unclear. The aim of this study was to assess the impact of type 2 diabetes on 30-day cardiac complications after vascular surgery. Patients undergoing elective vascular surgery between 2002 and 2011 were included in this retrospective cohort study. Previous diagnosis of type 1 and 2 diabetes and use of oral glucose-lowering medications and insulin were recorded. Patients with type 1 diabetes were excluded from the analysis. The main outcome parameter was cardiac complications, a composite of cardiovascular death, non-fatal myocardial infarction, congestive heart failure, severe arrhythmia and asymptomatic troponin release within 30 days of surgery. In multivariate analysis, corrections were made for comorbidities, demographics, medication use and surgical risk. Of 1462 patients, 329 (22.5%) patients had type 2 diabetes. Cardiac complications occurred in 155 (13.7%) patients without diabetes and in 68 (20.7%) with type 2 diabetes. In multivariate analysis, type 2 diabetes was associated with a significantly increased risk of 30-day cardiac complications (odds ratio 1.80; 95% confidence interval 1.25 to 2.60). Results were similar for type 2 diabetes patients managed with (odds ratio 1.84; 95% confidence interval 1.01 to 3.37) and without (odds ratio 1.79; 95% confidence interval 1.19 to 2.70) insulin. Type 2 diabetes is an independent risk factor for cardiac complications after vascular surgery and should be treated as such in preoperative cardiac risk stratification.

ABO blood type does not influence the risk of cardiovascular complications and mortality after vascular surgery.

OBJECTIVES: Thrombotic complications are common in vascular surgery patients. Non-O blood types are associated with an increased risk of thrombo-embolic diseases. The aim of this study is to assess the prognostic implications of non-O vs. O blood type regarding 30-day cardiovascular events and long-term mortality after vascular surgery. METHODS: The population of this retrospective cohort study consisted of 4679 patients undergoing elective major vascular surgery between the years 1990 and 2011. Baseline characteristics, ABO blood type and follow-up were obtained. Multivariable regression analyses, adjusted for age, gender, medical history, medication and smoking were used to evaluate the impact of non-O blood type on 30-day cardiovascular events (cardiovascular death, myocardial infarction and stroke) and long-term mortality. RESULTS: Non-O blood type was present in 2627 (56%) patients. Within 30 days after surgery, 129 (4.9%) non-O and 112 (5.5%) O patients suffered a cardiovascular event (P = 0.42). Non-O blood type was not associated with increased mortality during long-term follow-up (adjusted hazard ratio (aHR) 0.96; 95% confidence interval (CI) 0.88-1.04, with a median follow-up of 4 years). Anti-platelet and anticoagulant drugs did not interact with the relationship between ABO blood type and long-term outcome. CONCLUSION: Non-O blood type is not associated with either 30-day cardiovascular complications or long-term mortality in vascular surgery patients.

General anaesthesia is associated with adverse cardiac outcome after endovascular aneurysm repair.

OBJECTIVES: Endovascular aneurysm repair (EVAR) is associated with reduced cardiac stress compared with open repair and is an attractive therapeutic option, especially in cardiac fragile patients. General and locoregional anaesthesia differ regarding the stress response evoked by surgery. The aim of the study is to compare the incidence of cardiac events after EVAR under general or locoregional anaesthesia. METHODS: A total of 302 consecutive patients undergoing infrarenal EVAR between 2002 and 2011 were analysed in this retrospective cohort study. Selection of anaesthesia type was at the discretion of the treating physicians. Medical history, medication use, anaesthesia technique and follow-up were obtained. The study end point was 30-day cardiac complications, including cardiac death, non-fatal myocardial infarction, heart failure, ventricular arrhythmia and troponin T release. Multivariable analysis, adjusted for the propensity of receiving a locoregional technique and cardiac risk factors according to the Revised Cardiac Risk Index, was used to assess the association between cardiac events and anaesthesia type. RESULTS: A total of 173 patients underwent general anaesthesia and 129 locoregional anaesthesia. Obesity, aspirin use and therapeutic anticoagulation were more common in patients receiving general anaesthesia. Cardiac events were observed in 13.3% of patients receiving general anaesthesia and in 4.7% of patients receiving locoregional anaesthesia (P = 0.02), or 6.4% versus .8% (P = 0.02) when asymptomatic troponin release is excluded from the end point. In the general anaesthesia group, two cardiac deaths, six non-fatal myocardial infarctions, two cases of non-fatal heart failure, one non-fatal cardiac arrest and 12 cases of troponin T release were observed, compared with one myocardial infarction and five cases of troponin T release in the locoregional anaesthesia group. In multivariable analysis, general anaesthesia was associated with adverse cardiac events (odds ratio (OR) 3.8; 95%-confidence interval (CI) 1.1-12.9). Non-cardiac complications occurred in 11.6% of patients in both groups (P = 1.00). CONCLUSION: General anaesthesia was associated with an increased risk of cardiac events in EVAR, compared with locoregional anaesthesia.