The role of the ureter in diseases of the genitourinary tract

Abstract

1. 1. The history of urinary surgery indicates that comparatively little attention was given to the anatomical importance of the ureter until very recent times. The introduction of safe methods of pyelography has done more to familiarize the surgeon with this duct and its pathology than any other single factor. 2. 2. Embryologically the ureter takes its origin as a bud from the lower end of the Wolffian duct, close to its point of opening into the cloaca. When the cloaca disappears in the process of development, the ureter acquires a separate opening and a bulbous tip which later splits in two indicating future division into calyces. Incomplete or double ureter probably comes from a premature bifurcation of this tip, or an abnormal split which includes the stalk. Most anomalies of number and form probably arise at this point in fetal development. Huntingdon contends that double ureters have separate buds. 3. 3. The most important points in the anatomy of the ureter are its areas of narrowing and the arrangement of muscle fibers at its vesical end which serve to prevent regurgitation from the bladder. The exact nature of this mechanism is not well understood but it is the present writer's opinion that there is a definite arrangement of nerves and muscles which serves the purpose of a sphincter. Regurgitation is very likely aided also by ureteral peristalsis. Under conditions of disease dilatation of the ureter undoubtedly occurs and the condition known as megaloureter is established, wherein rise of pressure within the vesical cavity may force the contained urine back into the ureters even entirely to the renal pelvis. 4. 4. Stricture of the ureter is a definite clinical entity, occurring somewhat frequently in urologic practice though perhaps not quite as often as some enthusiasts would have us believe. Pathologic stricture is more likely to take place at the points of anatomical narrowing, and calculus formation is undoubtedly favored by the existence of infection in these strictured areas, the stone being a result rather than a cause of the stricture as has been generally believed. 5. 5. Ureteritis cystica is a rare form of ureteral inflammation to which little or no attention has been given in textbooks. The condition is not peculiar to the ureter but may be present in bladder and renal pelvis as well. Ureterocele, or cystic dilatation of the lower end of the ureter, should not be confused with ureteritis cystica. This may possibly be congenital in a few instances but is much more reasonably regarded as a gradually progressive condition acquired through many years. Ureteral prolapse is a separate entity. 6. 6. Primary infections of the ureter are not very common; while the ureter may be infected by venereal diseases, tuberculosis and so forth, this is usually only an extension from kidney or bladder. Tuberculosis is undoubtedly a frequent cause of ureteral stricture and obstruction. 7. 7. Ureteral calculi may have formed in the kidney and descend to the ureter, or they may originate in strictures or from other causes in the ureter itself. They should be removed by intravesical manipulations if possible. Patience and perseverence will usually accomplish this, and surgery should be only a last resort. 8. 8. Tumors of the ureter are a rare finding. Polyps are occasionally encountered, and benign papilloma has been reported in a few instances. Malignant neoplasms primary to the ureter are very seldom seen. Complete removal of any neoplasm should be promptly undertaken, as all benign growths tend rapidly to become malignant.