Pelvic Ureter

The pelvic ureter is the portion of the ureter extending from the pelvic brim to the urinary bladder. It begins where the abdominal ureter crosses the iliac vascular region and enters the pelvis. From this point, the ureter descends along the lateral pelvic wall before turning anteromedially toward the posterolateral surface of the urinary bladder.

The basic course is similar in males and females, but the terminal pelvic relationships differ because of the reproductive organs. In males, the ureter passes beneath the ductus deferens. In females, it passes beneath the uterine artery and lateral to the cervix before approaching the bladder. The terminal intramural portion of the ureter forms one of the most important sites of physiological narrowing.

Extent

The pelvic ureter begins at the pelvic brim and terminates at the ureteric orifice within the urinary bladder.

It represents the continuation of the abdominal ureter after the ureter crosses the iliac vessels.

Beginning at the Pelvic Brim

The transition from abdominal to pelvic ureter occurs near the bifurcation of the common iliac artery or over the proximal portion of the external iliac artery.

The precise relationship varies according to the level of arterial bifurcation and individual anatomy.

General Course

After entering the pelvis, the ureter descends along the lateral pelvic wall. It initially follows a relatively posterior course and then curves forward and medially toward the urinary bladder.

The terminal portion enters the posterolateral bladder wall and traverses it obliquely before opening into the bladder lumen.

Extraperitoneal Position

The pelvic ureter is primarily an extraperitoneal structure.

It lies beneath the pelvic peritoneum within connective tissue associated with the pelvic wall and viscera.

Lateral Pelvic Wall

During the first part of its pelvic course, the ureter descends along the lateral pelvic wall.

It lies in close relationship with pelvic fascia, branches of the internal iliac vessels, and autonomic nerve structures.

Relationship to the Internal Iliac Artery

The pelvic ureter descends in close relationship to the internal iliac artery and its branches.

Because branching patterns of the internal iliac artery vary considerably, the exact vascular relationships of the ureter also vary between individuals.

Relationship to the Internal Iliac Vein

The internal iliac veins and their tributaries occupy deeper pelvic planes and may lie close to the ureter during pelvic dissection.

Knowledge of these relationships is particularly important when the ureter is mobilized near the pelvic sidewall.

Parietal and Visceral Portions

The pelvic course can be described functionally as having a descending parietal portion along the lateral pelvic wall and a more anterior visceral portion directed toward the urinary bladder.

The change in direction occurs as the ureter leaves the pelvic sidewall and approaches the pelvic viscera.

Turn Toward the Bladder

After descending along the lateral pelvic wall, the ureter turns anteromedially toward the base of the urinary bladder.

It is during this terminal course that the most important sex-specific anatomical relationships occur.

Pelvic Ureter in Males

In the male pelvis, the ureter descends lateral to the rectum and then turns toward the urinary bladder.

Near the bladder, it passes inferior to the ductus deferens and lies lateral to the region of the seminal vesicle.

Relationship to the Rectum in Males

The rectum occupies the posterior midline of the male pelvis, while the ureters descend lateral to it.

As each ureter approaches the bladder, it moves anteriorly and medially away from the lateral pelvic wall.

Relationship to the Ductus Deferens

The ductus deferens crosses superior to the terminal pelvic ureter near the posterolateral surface of the urinary bladder.

The ureter therefore passes beneath the ductus deferens before entering the bladder wall.

Male Water Under the Bridge Relationship

The relationship between the ductus deferens and ureter can be remembered using the concept of "water under the bridge".

The ureter carrying urine represents the water, while the ductus deferens forms the structure crossing above it.

Relationship to the Seminal Vesicle

The terminal ureter is related to the seminal vesicle near the posterior surface of the urinary bladder.

The seminal vesicle lies medial to the terminal ureteric region, while the ureter approaches the posterolateral bladder wall.

Pelvic Ureter in Females

In females, the pelvic ureter descends along the lateral pelvic wall and passes in close relationship to the ovary and female reproductive tract.

It then travels through the connective tissue near the cervix and upper vagina before entering the urinary bladder.

Relationship to the Ovary

The ureter lies posterior and medial to the ovary as it descends along the lateral pelvic wall.

Its relationship to the ovarian fossa is important during operations involving the ovary and lateral pelvic structures.

Ovarian Fossa

The ovarian fossa is a depression on the lateral pelvic wall occupied by the ovary.

The ureter is related to the posterior region or floor of this area and must be considered during ovarian surgery.

Relationship to the Uterine Artery

Near the cervix, the uterine artery crosses superior to the ureter.

The ureter therefore passes beneath the uterine artery before continuing toward the urinary bladder.

Female Water Under the Bridge Relationship

The relationship between the uterine artery and ureter is classically remembered as "water under the bridge".

The ureter represents the water, while the uterine artery represents the bridge crossing above it.

Relationship to the Cervix

The ureter passes lateral to the cervix of the uterus during its terminal pelvic course.

It commonly lies approximately 1 to 2 cm lateral to the cervix, although this relationship varies and may be altered considerably by pelvic disease.

Relationship to the Broad Ligament

The ureter passes through connective tissue associated with the base of the broad ligament.

Its course in this region is extraperitoneal and closely related to the uterine vessels and parametrial tissues.

Relationship to the Upper Vagina

After passing lateral to the cervix, the ureter continues toward the bladder in close relationship with the upper vagina.

It lies near the lateral vaginal fornix before entering the bladder wall.

Male and Female Relations

Feature	Male Pelvic Ureter	Female Pelvic Ureter
Structure crossing superiorly near bladder	Ductus deferens	Uterine artery
Important reproductive relation	Seminal vesicle	Cervix and upper vagina
Posterior pelvic relation	Lateral to rectum	Related to lateral pelvic wall and ovary
Terminal destination	Posterolateral bladder wall	Posterolateral bladder wall

Approach to the Urinary Bladder

In both sexes, the pelvic ureter ultimately approaches the posterolateral surface of the urinary bladder.

It penetrates the bladder wall obliquely rather than entering at a right angle.

Ureterovesical Junction

The ureterovesical junction is the region where the ureter enters the urinary bladder.

It includes the transition from the extravesical ureter into the oblique intramural segment within the bladder wall.

Intramural Ureter

The intramural ureter passes obliquely through the bladder wall before opening into the bladder lumen.

This is the terminal and narrowest portion of the ureteric pathway.

Functional Valve Mechanism

The oblique intramural course contributes to a functional antireflux mechanism.

As the bladder fills and its wall becomes stretched, pressure on the intramural ureter helps limit retrograde movement of urine from the bladder toward the kidney.

Ureteric Orifice

The intramural ureter terminates at the ureteric orifice on the internal surface of the urinary bladder.

The right and left ureteric orifices form the superolateral corners of the bladder trigone.

Trigone of the Urinary Bladder

The trigone is a smooth triangular region of the internal bladder base.

Its three corners are formed by the two ureteric orifices superiorly and the internal urethral orifice inferiorly.

Terminal Constriction

The ureterovesical junction and intramural ureter form one of the major sites of physiological ureteric narrowing.

This region is clinically important because ureteric calculi commonly encounter resistance as they approach the bladder.

Major Ureteric Constrictions

Three regions are traditionally emphasized as sites of relative narrowing:

1. The ureteropelvic junction
2. The region where the ureter crosses the pelvic brim and iliac vessels
3. The ureterovesical junction and intramural ureter

Pelvic Ureter and Constrictions

The pelvic ureter begins near the second traditional narrowing at the pelvic brim and terminates at the third narrowing within the bladder wall.

These regions are important when interpreting the location of ureteric calculi and obstruction.

Ureteric Wall

The pelvic ureter consists of a mucosa, smooth muscle coat, and outer adventitial connective tissue.

The mucosa is lined by urothelium and forms longitudinal folds when the ureter is not distended.

Urothelium

Urothelium, also called transitional epithelium, lines the lumen of the pelvic ureter.

Its specialized cells provide a barrier to urine while allowing the ureteric lumen to accommodate changes in diameter.

Muscular Wall

Smooth muscle forms a substantial component of the ureteric wall and generates the contractions required to propel urine.

Distally, the muscular organization becomes more complex, with an additional outer longitudinal layer commonly described in the lower ureter.

Adventitia

The outer adventitia contains connective tissue, blood vessels, lymphatics, and autonomic nerve fibers.

Preservation of this tissue is important because the ureter receives much of its blood supply through vessels traveling within and along the adventitia.

Peristalsis

The pelvic ureter actively transports urine by coordinated peristaltic contractions.

These contractions continue the propulsive activity initiated in the upper urinary collecting system and move urine toward the bladder.

Blood Supply

The pelvic ureter receives a segmental arterial supply from nearby pelvic vessels.

Branches may arise from the common iliac, internal iliac, superior vesical, inferior vesical, uterine, vaginal, and other regional arteries depending on sex and level.

Sex Differences in Arterial Supply

In males, branches associated with the vesical arterial system contribute to the lower ureter.

In females, branches from the uterine and vaginal arteries may contribute to the blood supply of the terminal pelvic ureter.

Longitudinal Arterial Anastomoses

Segmental arteries supplying the ureter communicate through longitudinal vessels within the periureteric adventitia.

This arrangement is important surgically because excessive circumferential stripping can compromise ureteric perfusion.

Venous Drainage

Venous drainage generally parallels the arterial supply.

Blood from the pelvic ureter drains through veins associated with the iliac and vesical systems and, in females, through uterine and vaginal venous pathways.

Lymphatic Drainage

Lymph from the pelvic ureter drains primarily toward lymph nodes associated with the iliac vessels.

Common iliac, external iliac, and internal iliac lymphatic pathways may participate depending on the level of the ureter.

Innervation

Autonomic fibers reach the pelvic ureter through the superior and inferior hypogastric plexuses and associated pelvic autonomic networks.

These fibers accompany vascular and connective tissue pathways surrounding the ureter.

Visceral Afferent Fibers

Visceral afferent fibers convey sensory information from the ureter, including signals associated with distension and strong muscular contraction.

Obstruction can therefore produce severe visceral pain with characteristic patterns of referral.

Ureteric Pain

As a calculus descends through the pelvic ureter, referred pain may migrate from the flank and lower abdomen toward the groin and external genital region.

The changing pain distribution reflects the level of ureteric stimulation and its segmental sensory pathways.

Ureteric Calculi

Ureteric calculi may become impacted within the pelvic ureter, particularly near the ureterovesical junction.

Obstruction produces increased proximal pressure, ureteric distension, and vigorous smooth muscle contractions that contribute to ureteric colic.

Ureterovesical Junction Stones

The ureterovesical junction is a common location for an obstructing ureteric calculus because of the relatively narrow intramural segment.

A stone reaching this level is anatomically close to entering the urinary bladder but may produce intense symptoms while obstructing the terminal ureter.

Hydroureter and Hydronephrosis

Persistent obstruction of the pelvic ureter can cause dilation of the ureter proximal to the obstruction, producing hydroureter.

If pressure is transmitted to the renal collecting system, hydronephrosis may also develop.

Vesicoureteral Reflux

Vesicoureteral reflux is retrograde movement of urine from the bladder into the ureter and potentially toward the kidney.

It may occur when the normal antireflux function of the ureterovesical junction and intramural ureter is inadequate.

Importance of Intramural Length

An adequate oblique intramural course helps maintain the functional valve mechanism at the ureterovesical junction.

Developmental abnormalities affecting this relationship can predispose to vesicoureteral reflux.

Gynecological Surgery

The pelvic ureter is particularly important during gynecological surgery because of its relationships with the uterine artery, cervix, upper vagina, and ovarian vascular structures.

Hysterectomy and other procedures involving the parametrial tissues require careful identification and protection of the ureter.

Hysterectomy

During hysterectomy, the ureter is vulnerable where the uterine artery crosses above it near the cervix.

Incorrect placement of clamps, sutures, or energy devices can injure, ligate, or thermally damage the ureter.

Male Pelvic Surgery

In males, the terminal ureter is important during surgery involving the urinary bladder, seminal vesicles, ductus deferens, prostate region, and adjacent pelvic tissues.

Its relationship beneath the ductus deferens provides a useful landmark near the bladder.

Colorectal Surgery

The pelvic ureter may also be encountered during colorectal procedures involving the sigmoid colon, rectum, and pelvic sidewall.

Identification of the ureter is especially important during extensive dissection for malignancy, inflammatory disease, or recurrent surgery.

Ureteric Injury

Pelvic ureteric injury can result from transection, ligation, crushing, thermal damage, ischemia, or incorporation into sutures.

The risk increases when normal anatomy is distorted by tumors, endometriosis, inflammation, fibrosis, adhesions, previous surgery, or congenital abnormalities.

Preservation of Blood Supply

The ureter should be mobilized carefully because its arterial supply is segmental and depends on longitudinal vessels within the periureteric adventitia.

Excessive stripping of surrounding connective tissue may compromise perfusion and predispose to ischemia or subsequent stricture formation.

Pelvic Masses

Masses arising from pelvic organs can compress or displace the ureters.

Uterine, cervical, ovarian, bladder, colorectal, lymphatic, and other pelvic lesions may therefore alter the normal course of the pelvic ureter.

Pelvic Ureter Course

1. The abdominal ureter reaches the pelvic brim.
2. It crosses the iliac vascular region and enters the pelvis.
3. The ureter descends along the lateral pelvic wall beneath the peritoneum.
4. It lies near branches of the internal iliac vessels.
5. It turns anteromedially toward the urinary bladder.
6. In males, the ductus deferens crosses above the terminal ureter.
7. In females, the uterine artery crosses above the ureter near the cervix.
8. The ureter approaches the posterolateral bladder wall.
9. It enters the bladder at the ureterovesical junction.
10. It traverses the bladder wall obliquely as the intramural ureter.
11. It opens into the bladder at the ureteric orifice.

Key Anatomical Features

• The pelvic ureter extends from the pelvic brim to the urinary bladder.
• It begins after the ureter crosses the iliac vascular region.
• It is primarily extraperitoneal.
• It initially descends along the lateral pelvic wall.
• It is related to branches of the internal iliac vessels.
• It subsequently turns anteromedially toward the bladder.
• In males, the ductus deferens crosses superior to the ureter.
• In females, the uterine artery crosses superior to the ureter.
• The female ureter passes lateral to the cervix and near the upper vagina.
• The male terminal ureter is related to the seminal vesicle region.
• The ureter enters the posterolateral bladder wall obliquely.
• The intramural ureter contributes to the antireflux mechanism.
• The ureterovesical junction is an important site of relative narrowing.
• The pelvic ureter has a segmental blood supply derived from nearby pelvic vessels.

Clinical Importance

The pelvic ureter is clinically important because its course brings it into close relationship with major pelvic vessels, reproductive organs, the rectum, and the urinary bladder. These relationships differ between males and females and are essential landmarks during urological, gynecological, and colorectal surgery.

The ureterovesical junction and intramural ureter form the terminal region of relative narrowing and are important sites of ureteric stone impaction. The oblique intramural course also provides an important functional mechanism limiting reflux of urine from the bladder into the ureter.

Understanding pelvic ureter anatomy provides the foundation for studying ureteric constrictions, ureteric calculi, vesicoureteral reflux, hydroureter, hydronephrosis, hysterectomy, pelvic surgery, ureteric injury, bladder anatomy, and the anatomical relationships between the urinary and reproductive systems.