DRK Hospital Berlin;
Koepenick;
Germany;
Helios Hospital;
Bad Saarow;
Germany;
Sachsenhausen Hospital;
Frankfurt/Main;
Germany;
SRH Municipal Hospital;
Gera;
Germany;
StatConsult;
Magdeburg;
Germany;
University Hospital;
Magdeburg;
Germany;
Roux-en-Y-Gastric; Bypass; Circular; versus; Linear; versus; Hand-Sewn; Anastomosis; Complications;