Influence of high- and low-volume liver surgery in gallbladder carcinoma

Figure 1 Box plots of the annual volume of liver resections, separated according to volume strata and occurrence of re-resection (T2-3 carcinomas). The middle bar of the box plot represents the median, while the lower and upper bars of the box represent the 25^th and 75^th quartiles, respectively. The dots and asterisks represent outliers.

Figure 2 ANOVA of high/mid-volume vs low-volume centers according to the mean rate of liver resection.

Figure 3 Mean rate of liver resection in the 3 volume groups including all patients/all volume centers.

Figure 4 Medians of liver resections according to the 3 volume groups (Tis-T4 carcinomas/all patients). The middle bar of the box plot represents the median, whereas the lower and upper bars of the box represent the 25^th and 75^th quartiles, respectively. The dots and asterisks represent outliers. The boxplot-test of all patients/volume-centers shows that the median of liver resection at high-volume centers was 60, that at mid-volume centers was 28 and that at low-volume centers was 5.