Abstract: A working channel device is mountable on the outer circumference of an endoscope, such as an endoscope of the flexible shaft design. The device has a tubular or hose-like working channel and a distal fixing element that can be fixed to the working channel. The distal fixing element can engage around the endoscope in a clamping manner at the endoscope head of the endoscope. A proximal fixing element can be fixed to the working channel, which can engage around the endoscope, preferably at the endoscope grip of the endoscope. A preferably sleeve-like adapter can be mounted at the proximal end of the working channel of the working channel device. The adapter has or forms the proximal fixing element and additionally forms a connection point/interface for the connection of medical devices.

Abstract: A treatment instrument which can be coupled to a distal end of an endoscope and has a hollow body and a gripping element. The gripping element can be operated via an actuation mechanism situated inside the hollow body. The gripping element is configured in the form of a cap with which a distal end of the hollow body can be closed. The invention also relates to an endoscope having a distal end which is coupled or can be coupled to a treatment instrument according to the invention.

Abstract: A working channel device is mountable on the outer circumference of an endoscope, such as an endoscope of the flexible shaft design. The device has a tubular or hose-like working channel and a distal fixing element that can be fixed to the working channel. The distal fixing element can engage around the endoscope in a clamping manner at the endoscope head of the endoscope. A proximal fixing element can be fixed to the working channel, which can engage around the endoscope, preferably at the endoscope grip of the endoscope. A preferably sleeve-like adapter can be mounted at the proximal end of the working channel of the working channel device. The adapter has or forms the proximal fixing element and additionally forms a connection point/interface for the connection of medical devices.

Abstract: A method for observing a mucosa of a biliary or pancreatic system in a subject includes positioning a optical probe in contact with said mucosa, wherein the optical probe accesses the biliary or pancreatic system using a working channel of an endoscope inserted orally in the subject. An optical probe to be used with a fiber optic microscope for in vivo observation includes an optical fiber bundle, a miniaturized objective connected coaxially at a distal tip of the optical fiber bundle, wherein the optical fiber bundle and the miniaturized objective each have a diameter of less than 1.2 mm such that said optical probe can access a biliary or pancreatic system using a working channel of an endoscope inserted orally.