Insertion sleeve comprises a shaft (5) having an inner tubular element (1) axially sliding in an outer tubular element (2). A traction element (4) is hinged on one tubular element and the other tubular element has an angled piece on its distal end (7). Independent claims are also included for the following: (1) Handle for operating an angled piece and (2) Over tube for inserting one or more insertion sleeves. Preferred Features: The angled piece is arranged on the inner tubular element and the traction element is hinged on the outer tubular element to operate the angle piece.