There are no three physiological narrowings in the upper urinary tract: a new concept of the retroperitoneal anatomy
Minobu Kamo1,2,3, Taiki Nozaki4,5, Saya Horiuchi4,5
1Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistrasse 52, 20246, Hamburg, Germany. kamominobu@gmail.com.
Abstract:
The widely held dogma of three physiological narrowings in the upper urinary tract has proven incorrect by recent several studies using computed tomography images. There are only two common obstruction sites: the upper ureter and the ureterovesical junction. The second narrowing, where the ureter crosses the iliac vessels, cannot be regarded anymore as a common obstruction site. The mechanism by which stones lodge in the upper ureter is explained anatomically by the change in ureteral mobility and compliance at the level where the ureter exits the perirenal space. This level can be identified radiologically as the point where the ureter crosses under the ipsilateral gonadal veins, termed the "crossing point". Kinking of the upper ureter is another manifestation of this anatomical phenomenon, visible in radiological images. It is caused by loosening of the ureter at or above the crossing point (within the perirenal space), corresponding with renal descent such as during the inspiratory phase. This new anatomical discovery in the retroperitoneum will not only bring about a paradigm shift in terms of the physiological narrowings in the upper urinary tract, but may also lead to the development of new surgical concepts and approaches in the area.
Related Concept Videos
01:22Ureters
01:11Anatomy of the Genitourinary System I: Kidneys and Ureters
01:19Anatomy of the Genitourinary System II: Bladder and Urethra
01:23Urinary Bladder
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric...
01:22Imaging Studies V: Intravenous Urography and Retrograde Pyelography
01:13Introduction to Urinary System
The kidneys are bean-shaped organs located in the retroperitoneal space, on either side of the vertebral column, between the T12 and L3 vertebrae. They are partially protected by the rib cage and surrounded by perirenal fat, which provides cushioning. They are responsible for urine formation and play critical roles in regulating blood pressure, electrolyte levels, and hormone production. The ureters...