The invention relates to a connection device for merging at least two line sections in a vacuum-based wound treatment system, wherein the two line sections are arranged on the wound side in relation to the connection device, and wherein the connection device, on the side thereof facing away from the wound, can be connected to a third, multi-lumen line section leading to a vacuum-generating device； the connection device is designed, according to the invention, such that the at least two line sections have a multi-lumen configuration and these line sections each have a multi-lumen attachment device that can be brought into flow communication with the connection device, and such that separate lumens of the two line sections on the wound side also remain separate from each other inside the connection device and inside the third line section.
