Anatomy Of Ureter In Female

The Retroperitoneal Course

The ureter begins at the renal pelvis and descends along the anterior surface of the psoas muscle. It crosses over the bifurcation of the common iliac artery near the sacroiliac joint. This is the standard landmark everyone memorizes for boards. In actual surgery, the point where it crosses the external iliac vessels is often more useful because the common iliac bifurcation can vary by a centimeter or two depending on patient habitus. It runs forward on the levator ani, then turns medially and anteriorly to enter the bladder at the trigone. The intramural portion is about 1.5 to 2 centimeters long. This oblique tunnel through the detrusor muscle acts as a physiological valve. When bladder pressure rises during voiding, the surrounding muscle compresses the ureter and prevents backflow. That is the reason you generally do not see vesicoureteral reflux in a normal system.

Key Landmarks In The Anatomy Of Ureter In Female Pelvis

The most important relationship in female pelvic surgery is where the ureter passes under the uterine artery. Surgeons call this "water under the bridge." The ureter runs approximately 1 to 2 centimeters lateral to the internal cervical os, within the cardinal ligament. The uterine artery crosses over it from lateral to medial. This is why the ureter is at risk during hysterectomy when the uterine pedicle is being ligated. It is also why the ureter can be injured during colposuspension procedures if the needle is placed too deep or too lateral near the arcus tendineus. Another critical landmark is the ovarian vessel. The ureter crosses posterior to the infundibulopelvic ligament as it enters the pelvis. During bilateral salpingo-oophorectomy, particularly laparoscopic cases, a clip or energy device placed too close to the pelvic sidewall can injure the ureter. The distance between the ovarian pedicle and the ureter is variable, ranging from about 5 millimeters to over 2 centimeters depending on anatomy. The ureter also passes near the ischial spine and the obturator internus muscle on its way to the bladder. During pelvic lymph node dissection, especially the obturator node packet, the ureter is at risk if the dissection extends too far laterally along the pelvic sidewall. I have seen cases where retraction of the ovarian vein away from the psoas exposes the ureter, and that is about as good as it gets for visualization. Sometimes you simply have to trace it deliberately rather than assuming its location.

The Blood Supply And Why It Matters

The ureter has a segmental axial blood supply coming from multiple sources. The upper third receives branches from the renal artery. The middle third gets supply from the gonadal artery, the common iliac artery, and sometimes the abdominal aorta directly. The lower third is supplied by the superior vesical artery and branches from the internal iliac system. This longitudinal anastomotic network means that a single segmental vessel can be sacrificed with relatively low risk of ischemia, provided the remaining longitudinal channels are preserved. The distal third is more vulnerable because its blood supply is less robust and more dependent on the vesical branches. During procedures that require extensive mobilization of the bladder from the cervix and upper vagina, such as radical hysterectomy or sacrocolpopexy, the blood supply to the distal ureter can be compromised. The clinical consequence is ureteral stricture, which may not present for weeks or months after surgery. Patients come back with flank pain, recurrent UTIs, or unexplained renal function decline. It is a slow problem, not an acute one, which makes it easy to miss in the immediate postoperative period. I once managed a case where a patient developed a complete ureteral obstruction six weeks after a laparoscopic sacrocolpopexy. The graft had been fixed to the anterior longitudinal ligament of the sacrum, and the dissection was fairly standard. The ureter had kinked at the point where it was tacked down too medially during mesh fixation. We confirmed it with a CT urogram showing hydronephrosis on that side. A percutaneous nephrostomy was placed first to relieve the obstruction, and then a ureteral stent was passed retrograde. Eventually it resolved without needing open reconstruction, but it was a reminder that even standard bariatric and reconstructive pelvic cases can produce unexpected complications when the ureter is not actively visualized.

The Peritoneal Relationships

The ureter is a retroperitoneal structure. It lies beneath the peritoneum of the posterior abdominal wall, which means it is covered by peritoneum only on its anterior surface. During open or laparoscopic pelvic surgery, the peritoneum must be incised to access the ureter if you plan to mobilize it. The broad ligament covers the ureter laterally in the pelvic cavity, and the parametrium contains it medially. Tracing the ureter surgically usually means incising the peritoneum just lateral to its course and reflecting it medially. The gonadal vessels are a reliable landmark for finding the ureter. They cross anterior to the ureter as they descend toward the ovary. If you locate the ovarian vessels where they cross the psoas, you can follow them distally to find the ureter underneath. This is the standard teaching for identifying the ureter during gynecologic surgery. The problem is that the ovarian vessels can be short or absent in postmenopausal women, making this landmark less useful. In those cases, you trace along the psoas muscle itself, where the ureter typically appears as a whitish cord-like structure pulsating slightly with adjacent arterial flow. The anterior branch of the internal iliac artery is another consistent landmark. The ureter crosses over it near the origin of the umbilical artery. During pelvic exenteration or radical cancer surgery, this relationship becomes critical because the surgeon needs to identify every structure before ligating vessels. Missing the ureter at this level can lead to devastating injury. I prefer to skeletonize the internal iliac system first, identify its branches, and then trace the ureter medially from that point rather than the other way around.

Technical Nuances And Pitfalls

Ureteral injury is the most common visceral injury during laparoscopic gynecologic surgery. The majority occur during hysterectomy, particularly laparoscopic total hysterectomy where the uterine arteries are sealed with energy devices. The energy can cause thermal injury to the ureter even without direct contact. The thermal spread from bipolar or ultrasonic devices can extend several millimeters beyond the active tip, which is enough to damage the ureter if it is lying right against the vessel being sealed. Irrigation during energy application reduces thermal spread, and using lower power settings on the bipolar device makes a measurable difference in reducing collateral damage. Vaporization injuries are different from transection injuries. A complete transection is usually recognized immediately because you can see the leak or the severed end. A vaporization or thermal injury may not be obvious at the time of surgery. The ureter looks normal externally. The patient goes home feeling fine. Three to four weeks later, she presents with fever, flank pain, and a rising creatinine. The tissue necrotizes gradually, a stricture forms, and the ureter obstructs. This is the scenario that gets sued because it was not caught intraoperatively. Some surgeons use intraoperative cystoscopy with IV indigo carmine or fluorescein to check for urine efflux from both ureteral orifices after hysterectomy. It adds about ten minutes to the case and catches a significant number of injuries that would otherwise go unnoticed. During endometriosis surgery, the ureter can be encased in fibrotic tissue or displaced medially by deep infiltrating nodules. The classic teaching says the ureter is about 1.5 centimeters lateral to the cervix, but endometriosis can pull it much closer or even beneath the uterine artery in a completely altered relationship. I have seen cases where the ureter was adherent to the posterior leaf of the broad ligament, buried in endometriotic plaque along the uterosacral ligament. Mobilizing it required careful dissection under direct vision. Stenting the ureter preoperatively made the tissue pliable and easier to identify, though it did not eliminate the risk entirely.

The ureter is about 25 to 30 centimeters long in adults. Its lumen is narrowest at the ureteropelvic junction, at the pelvic brim where it crosses the iliac vessels, and at the ureterovesical junction. The narrowest point clinically is the UVJ, which is why ureteral stones frequently get stuck there. When placing a ureteral stent, the curve at the UVJ is the point of resistance. Forcing a stent past that curve without adequate lubrication or proper angle can cause trauma to the ureteral wall. Slow advancement with clockwise rotation of the stent tip usually gets past the curve without injury.

Imaging And Assessment

A standard non-contrast CT is good for detecting stones but does not show the ureter well unless there is hydronephrosis. A CT urogram with contrast in the excretory phase gives the best overall view of the entire ureteral course and identifies strictures, fistulas, and extrinsic compression. For surgical planning, some urologists use MR urography, which provides excellent soft tissue detail and is useful when evaluating endometriosis involvement of the ureter. Ultrasound can detect hydronephrosis but cannot reliably visualize the mid-ureter due to bowel gas interference. Cystoscopy with retrograde pyelogram remains the gold standard for assessing ureteral patency intraoperatively. Dye injected retrograde through the ureteral orifice outlines the entire ureter on fluoroscopy. It takes about five minutes and provides immediate information about any obstruction or leak. It is not routinely done in every gynecologic case, but it should be strongly considered in complex pelvic surgery, revision surgery, or when there is any doubt about ureteral integrity. The Anatomy Of Ureter In Female is not a static diagram. It varies with pregnancy, pelvic pathology, prior surgery, and body habitus. The standard textbooks give you average measurements and ideal relationships. In practice, the ureter moves. It gets pushed, pulled, stretched, and buried in scar tissue. Recognizing the consistent landmarks and understanding the variations is what separates a safe case from a regrettable one. There is no shortcut for careful dissection and deliberate identification of the structure before cutting, clipping, or cauterizing anything nearby.