Systems and methods are disclosed that include a guide catheter apparatus insertable through a external body passage of a subject. The guide catheter apparatus includes a substantially rigid shaft and a handle. The shaft has a proximal opening, a distal opening, and a lumen extending between the proximal opening and the distal opening. The handle has a structure to allow a position of the guide catheter to be controlled by some or all of three fingers of one hand of an operator of the handle. The structure of the handle is adapted to permit the operator to position a thumb and index finger of the hand to manipulate a working device inserted into the lumen of the guide catheter, where the working device is manipulable via a portion of the working device immediately adjacent to the handle.