The method of treating an injured ureter varies greatly and will depend not only on the extent of the damage, but also on the time at which it is recognized. For example, if the surgeon recognizes the injury in the course of the operation, he will be able to deal with it at once. This we may term _immediate_ treatment. The more difficult cases are those in which the injury is unrecognized at the time of the operation and only becomes obvious in the course of convalescence; the treatment in such circumstances may be called _secondary_. The primary treatment of an injury to a ureter in the course of a pelvic operation will depend in a large measure on the ability, judgment, and experience of the surgeon, as well as on the extent of the injury. For example, if the ureter be partially divided, the opening may be closed with sutures of thin silk; when the duct is completely divided, the cut ends may be invaginated, the upper into the lower, and retained in position by suture. When five or more centimetres of the ureter have been accidentally exsected, none of these methods is applicable; in such circumstances several plans have been tried. Of these the simplest is ligature of the proximal end with the hope of inducing atrophy of the kidney; in several recorded instances this has proved successful. The surgeon who adopts this method should satisfy himself that the patient has another kidney, and that it is, as far as he can ascertain at the time, healthy. Some surgeons who have divided a ureter have promptly removed the corresponding kidney; others have secured the proximal end in the upper angle of the abdominal incision and removed the kidney subsequently. [Illustration: FIG. 27. THE RELATION OF PARTS AFTER RICARD’S OPERATION OF URETERO-CYSTO-NEOSTOMY (after Lutaud). A, the proximal end of the ureter with the mucous membrane reflected. B, the walls of the bladder, showing the mode of fixing the ureter to its walls. 1 and 2, sutures.] It has been suggested that when a portion of a ureter has been resected and the proximal end cannot be engrafted into the wall of the bladder, it should be turned into the cæcum or the sigmoid flexure, according to its position, and thus preserve to the patient the kidney and save her the distress of a urinary fistula. This method has not found favour with practical surgeons. The most promising procedure consists in engrafting the proximal end of the cut ureter into the bladder. This is known as uretero-cysto-neostomy, an operation which has been made the subject of a valuable thesis by Dr. Lutaud. This thesis appears to have been inspired as a result of two successful operations performed by Ricard. The principle of this method is as follows:--