Variable life adjusted display methodology for continuous performance monitoring of carotid endarterectomy.

Introduction The aim of this study was to use variable life-adjusted display (VLAD) methodology to monitor performance of six vascular surgeons undertaking carotid endarterectomy in a single institution. Materials and methods This was a prospective study with continuous analysis. A risk score model to predict 30-day stroke or death for individual patients was developed from data collected from 839 patients from 1992 to 1999. The model was used to monitor performance of six surgeons from 2000 to 2009. Individual risk factors and 30-day outcomes were analysed and VLAD plots were created for the whole unit and for each surgeon. Results Among the 941 carotid endarterectomies in the performance analysis, 28 adverse events were recorded, giving an overall stroke or death rate of 3.06%. The risk model predicted there would be 33 adverse events. There was no statistical difference between the predicted and the observed adverse events (P > 0.2, χ2 value 1.25, 4 degrees of freedom). The VLAD plot for the whole unit shows an overall net gain in operative performance, although this could have been chance variation. The individual VLAD plot showed that surgeons 1, 2, 3 and 6 to have an overall net gain in the number of successful operations. The changes observed between the surgeons was not significant (P > 0.05) suggesting chance variation only. Conclusions Performance of carotid endarterectomy can be continuously assessed using VLAD methodology for units and individual surgeons. Early identification and correction of performance variation could facilitate improved quality of care.

The role of hyperbaric oxygen therapy in ischaemic diabetic lower extremity ulcers: a double-blind randomised-controlled trial.

OBJECTIVE: ischaemic lower-extremity ulcers in the diabetic population are a source of major concern because of the associated high risk of limb-threatening complications. The aim of this study was to evaluate the role of hyperbaric oxygen in the management of these ulcers. METHOD: eighteen diabetic patients with ischaemic, non-healing lower-extremity ulcers were recruited in a double-blind study. Patients were randomly assigned either to receive 100% oxygen (treatment group) or air (control group), at 2.4 atmospheres of absolute pressure for 90 min daily (total of 30 treatments). RESULTS: healing with complete epithelialisation was achieved in five out of eight ulcers in the treatment group compared to one out of eight ulcers in the control group. The median decrease of the wound areas in the treatment group was 100% and in the control group was 52% (p=0.027). Cost-effectiveness analysis has shown that despite the extra cost involved in using hyperbaric oxygen, there was a potential saving in the total cost of treatment for each patient during the study. CONCLUSION: hyperbaric oxygen enhanced the healing of ischaemic, non-healing diabetic leg ulcers and may be used as a valuable adjunct to conventional therapy when reconstructive surgery is not possible.

POSSUM and P-POSSUM overpredict mortality for carotid endarterectomy.

OBJECTIVES: the aim was to test the predictive accuracy of POSSUM and P-POSSUM on patients undergoing CEA. DESIGN: retrospective and prospective study. MATERIALS: 499 CEAs performed by four vascular surgeons from a single unit from 1992-99. The median age was 68 (range 38-86) and 60% were men. METHODS: physiological parameters, operative parameters and the 30-day mortality were collected. Predicted mortality for each patient was calculated using POSSUM and P-POSSUM equations. Patients were stratified into risk groups and observed and predicted deaths were compared. Accuracy of the prediction was assessed using chi-squared analysis. RESULTS: the observed 30-day mortality was 1.8% (9/499). The predicted deaths using POSSUM and P-POSSUM analysis were 49 and 25 respectively compared to nine observed deaths. There was significant evidence of lack of fit of both models in predicting mortality (chi-squared analysis, p<0.05). CONCLUSIONS: POSSUM and P-POSSUM overpredict mortality and are unsuitable for comparative audit of CEA. Models developed specific for CEA might accurately predict mortality.

Risk modelling study for carotid endarterectomy.

BACKGROUND: The aims of this study were to identify factors that influence the risk of stroke or death following carotid endarterectomy (CEA) and to develop a model to aid in comparative audit of vascular surgeons and units. METHODS: A series of 839 CEAs performed by four vascular surgeons between 1992 and 1999 was analysed. Multiple logistic regression analysis was used to model the effect of 15 possible risk factors on the 30-day risk of stroke or death. Outcome was compared for four surgeons and two units after adjustment for the significant risk factors. RESULTS: The overall 30-day stroke or death rate was 3.9 per cent (29 of 741). Heart disease, diabetes and stroke were significant risk factors. The 30-day predicted stroke or death rates increased with increasing risk scores. The observed 30-day stroke or death rate was 3.9 per cent for both vascular units and varied from 3.0 to 4.2 per cent for the four vascular surgeons. Differences in the outcomes between the surgeons and vascular units did not reach statistical significance after risk adjustment. CONCLUSION: Diabetes, heart disease and stroke are significant risk factors for stroke or death following CEA. The risk score model identified patients at higher risk and aided in comparative audit.