The eligibility criteria is written anywhere else. The operation results after an single shot antibiotics in open method. The access happens via a semicircular infraumbilical cut. There will be prepared until the linea alba and the umbilical hernia orifice to display the hernia gap and the hernia sac. If there´s only a fat prolapse, it will be removed by ligation. If there´s an peritoneal hernia sac, the content will be repositioned and the hernia sac will be removed. The preperitoneal space will be prepared bluntly and the peritoneum will be released from the rectus sheath. A 4-6 cm trimmed mesh with a central thread will be inserted in underlay position. The central thread is used for orientation. The hernial gap will be closed in transversal direction with absorbable threads. After the reinsertion of the navel the region of the operation will be closed with subcutaneous und intracutaneous seams.