Ureters: Position, Relations, Gross
Structure
The ureters are
paired muscular ducts that convey urine from the kidneys to the bladder. Each
ureter begins medial to the ipsilateral kidney as a continuation of the renal
pelvis and ends upon insertion into the posterior bladder wall. The ureters are
retroperitoneal for their entire length, which is approximately 30 cm.
The ureters vary in diameter from 2 to 8 mm, increasing in size in the
lower lumbar area. They are generally narrowest at their origin from the renal
pelvis, at the crossing of the pelvic rim, and at their termination as they
traverse the bladder wall. As a result, renal stones (see Plate 6-3) most often
become impacted within or proximal to these three sites.
Abdominal Portion
As the ureters exit the kidneys, they pass anterior to the psoas muscles
and genitofemoral nerves. In addition, the right ureter lies posterior to the
second (descending) part of the duodenum. More inferiorly, near their entry
into the greater (false) pelvis, both ureters pass posterior to the gonadal
vessels.
The ureters also cross the unpaired vessels supplying the intestines. The
left ureter passes posterior to the left colic and sigmoid vessels, while the
right ureter passes posterior to the right colic, ileocolic, and terminal
superior mesenteric vessels. These vessels are contained within the fusion
fascia formed as the ascending and descending portions of the colon became
secondarily retroperitoneal. Thus they do not have ureteric branches and can be
easily mobilized along with the colon to access the ureters.
As the ureters enter the lesser (true) pelvis, they pass anterior to the
sacroiliac joint and common iliac vessels.
Pelvic Portion
The ureters enter the lesser pelvis anterior to the internal iliac
arteries. As they descend along the posterolateral pelvic wall, they run medial
to the obturator vessels/nerves and the superior vesical (umbilical) arteries.
At the level of the ischial spines, the ureters turn medially alongside
branches of the hypogastric bundle of nerves (see Plate 1-14). The other
anatomic relation- ships in the pelvic region differ between the two genders.
Male. Just before the entering the bladder, each ureter
passes inferior to the ipsilateral ductus (vas) deferens. At this point the
ureters lie superior and anterior to the seminal glands (vesicles).
Female. As the ureters descend along the lateral walls of
the lesser (true) pelvis, they course posterior and then parallel to the
ovarian vessels contained in the suspensory ligaments of the ovary. The ureters
pass medial to the origins of the uterine arteries from the internal iliac arteries.
As the ureters turn anteromedially from the pelvic wall, they run anterior and
parallel to the utero- sacral fold, posterior and inferior to the ovaries. As
they traverse the base of the broad ligament, about 1.5 cm lateral to the uterine cervix, the ureters
pass inferior to the uterine arteries
as the arteries course medially toward
the uterus.
Bladder Insertion
The ureters penetrate the thick wall of the bladder about 2.5 cm from the
midline. They run in an anteromedial
direction within the wall of the bladder and then terminate at the ureteric
orifices, which are 2 cm apart in the nondistended bladder. As intravesicular
pressure increases, the intramural portions of the ureters become compressed,
preventing reflux of urine. In this distended state, the ureteric orifices spread
to become 5 cm apart.
