Intrastomal 3D ultrasound; an inter- and intra-observer evaluation

The aim of this study was to determine intra- and interobserver reliability in 3D intrastomal ultrasound imaging of parastomal hernia and protrusion.

A total of 40 patients were investigated. Two or three physicians evaluated the images twice, 1 month apart.

Inter-observer agreement was 72 % with a kappa value 0.59. For the last 10 patients there was an agreement of 80 % with a kappa value of 0.70. Intraobserver agreement was 80 % for one observer and 95 % for the other. The learning curve levelled out at around 30 patients.

Considering the learning curve of 30 patients, 3D intrastomal ultrasound is a reliable investigation method. 3D intrastomal ultrasonography has the potential to be the investigation of choice to differentiate between a bulge, a hernia, or a protrusion.