Radical cystectomy: defining the threshold for a surgeon to achieve optimum outcomes

The reorganisation of cancer services in England will result in the creation of specialist high volume cancer surgery centres. Studies have suggested a relationship between increasing surgical volume and improved outcomes in urological pelvic cancer surgery, although to date, they have pre-defined the definition of "high" and "low" volume surgeons.

To derive the minimum caseload a surgeon requires to achieve optimum outcomes and to examine the effect of the operating centre size upon individual surgeon's outcomes.

All cystectomies performed for bladder cancer in England over 5 years were analysed from Hospital Episode Statistics (HES) data. Statistical analysis was undertaken to describe the relationship between each surgeon's annual case volume and two

in-hospital mortality rate, and hospital stay. The surgeon's outcomes were then analysed with respect to the overall level of activity in their operating centre.

A total of 6308 cystectomies were performed; the mean number of surgeons performing them annually was 327 with an overall mortality rate of 5.53%. A significant inverse correlation (-0.968, p<0.01) was found between case volume and mortality rate. Applying 95% confidence interval estimation, the minimum caseload required to achieve the lowest mortality rate was eight procedures per year. Increasing caseload beyond eight operations per year did not produce a significant reduction in mortality rate.

Analysis of HES data confirms an inverse relationship between surgeon's caseload and mortality for radical cystectomy. A caseload of eight operations per year is associated with the lowest mortality rate.