Skip to main content

The Ureters

The ureters are paired retroperitoneal muscular tubes ~25–30 cm long that pump urine from the renal pelvis to the bladder.[1][2] For the reconstructive urologist they are the single most consequential structure in upper-tract surgery: a tenuous blood supply that is easily devascularized, a course that is anatomically predictable but iatrogenically vulnerable, and a repertoire of physiologic behaviors (peristalsis, anti-reflux, response to obstruction) that determine how a reconstruction will actually function. This article focuses on the surgical anatomy, vascular supply, and functional behavior that matter at the table — not a molecular catalog of pacemaker channels.

Segmental Anatomy​

The ureter is conventionally divided into three segments based on the iliac vessels and the bony pelvis. This division is practical: it maps to the course on imaging, the expected relations during dissection, and the typical injury mechanisms for each zone.[2]

SegmentLandmarksKey relations
Proximal (upper)UPJ → crossing of the sacroiliac joint / iliac vesselsOn psoas; gonadal vessels cross anterior ~mid-length; aorta/IVC medial; lower pole of kidney / retroperitoneal fat lateral
MiddleOver the iliac vessels and bony pelvisCrosses the bifurcation of the common iliac artery — the most reliable anatomic landmark on laparoscopy
Distal (pelvic/lower)From iliac vessels → UVJDeep to superior vesical and uterine/vas deferens structures; enters the bladder obliquely

Course and relations​

From superior to inferior:

  • Retroperitoneal on psoas. Lies on the psoas major, medial to the genitofemoral nerve, covered by peritoneum. Mobilization requires recognition that the psoas is deep to the ureter.
  • Gonadal vessels. The gonadal artery and vein cross anterior to the ureter ("water runs over bridge") at approximately the level of the lower pole of the kidney / mid-ureter. In orchiectomy and ureteral dissection for retrocaval or high ureter, the two structures must be distinguished before ligation.
  • Common iliac bifurcation. The ureter crosses anterior to the bifurcation of the common iliac artery into internal and external iliac arteries. This is the single most reliable landmark to find the ureter during pelvic/vascular surgery.
  • Pelvic brim. After crossing the iliac vessels the ureter descends along the lateral pelvic sidewall against the obturator internus, posterior to the ovary in women, medial to the vas deferens in men.
  • Cardinal ligament and the uterine artery — "water under the bridge." In the female pelvis the uterine artery crosses anterior (superior) to the ureter ~1.5–2 cm lateral to the cervix within the cardinal ligament. This is the most common site of iatrogenic ureteral injury during hysterectomy — from thermal injury, ligation in hemostatic clamps, or inclusion in a cardinal-ligament pedicle.
  • Vas deferens. In men the vas crosses anterior to the distal ureter as it runs to the seminal vesicle.
  • Ureterovesical junction (UVJ). The ureter enters the bladder obliquely, travels ~1.5–2 cm within the detrusor, and opens at the trigonal corner. The oblique intramural course is the structural basis of the passive anti-reflux mechanism (see below).
Where the ureter is injured — the operative hotspots

The overwhelming majority of iatrogenic ureteral injuries occur at predictable points:

  1. The cardinal ligament / uterine artery crossing during hysterectomy (most common)
  2. The IP (infundibulopelvic) ligament during oophorectomy — the gonadal vessels run here alongside the ureter
  3. The bladder base / trigone during anterior colporrhaphy or anti-incontinence procedures
  4. Over the common iliac bifurcation during vascular and sigmoid surgery
  5. At the UPJ during renal / retroperitoneal dissection Identification and mobilization before ligation of any adjacent structure is the single most effective prevention.

Blood Supply​

The ureter has a segmental blood supply that is longitudinally redundant only because of an adventitial periureteric plexus running along its length. That plexus is the reason the ureter can be mobilized and yet survive — and the reason stripping the adventitia destroys it.

SegmentTypical arterial supplyApproach direction
Renal pelvis and proximal ureterRenal artery branchesMedial
Abdominal (middle) ureterGonadal artery, aorta, common iliacMedial
Pelvic ureterInternal iliac branches — uterine artery (F), superior/inferior vesical, middle rectal, vaginal (F)Lateral

Two practical consequences:

  • Adventitial preservation is sacrosanct. Dissect the ureter with its surrounding adventitial tissue in continuity. The longitudinal anastomotic plexus running in this adventitia is what perfuses the ureter between segmental feeders. Skeletonizing it — even during an otherwise elegant dissection — produces delayed ischemic stricture.
  • Approach direction matters. The abdominal ureter takes its blood supply medially (aortic/gonadal/common iliac branches); the pelvic ureter takes it laterally (internal iliac branches). When mobilizing the ureter, stay on the side opposite its blood supply for that segment — medial for abdominal, lateral for pelvic.

Venous and lymphatic drainage​

Veins parallel the arteries. Lymphatics follow the course of the ureter — renal and proximal ureteral lymph drains to the para-aortic / interaortocaval basins, middle to common iliac, distal to internal iliac / obturator nodes.

Innervation and Referred Pain​

Ureteral innervation is autonomic (sympathetic and parasympathetic) with a dense adventitial and intramural plexus, plus sensory afferents traveling with the sympathetic roots.[8][9][10]

The operative points:

  • Peristalsis is myogenic, not neurogenic. Complete autonomic denervation does not abolish peristalsis — the ureter will continue to contract. This is why ureter reimplantation, mobilization, and even transposition can work despite disrupting the extrinsic nerve supply.
  • Referred pain follows the sympathetic roots — T10–L2. Ureteral pain refers to the flank (upper segment), periumbilical region / groin (middle), and the scrotum/labium majus or anterior thigh (lower/intramural segment), mirroring the migrating stone.
  • Sensory density increases distally and is sex-dependent, with higher adventitial nerve density in women, particularly in the distal ureter.[9]

Ureteral Wall, Peristalsis, and What Matters at the Table​

The ureter is a three-layer tube — urothelium, smooth muscle arranged in heterogeneously oriented bundles (not discrete circular/longitudinal layers), and adventitia carrying the vessels and nerves.[3][4] Peristalsis is generated by pacemaker cells at the pelvis–kidney junction — morphologically distinct atypical smooth muscle cells that fire spontaneous depolarizations and drive a propagating wave distally.[6][7]

For operative reasoning the relevant features are:

  • Unidirectional pump, not a passive tube. Urine is delivered in discrete boluses, 5–7 s per contraction, and the oblique UVJ closes between waves. Any reconstruction that replaces ureter with passive conduit (ileal ureter, Boari flap if capacitance is misjudged) must account for the loss of active propulsion.
  • Acute vs. chronic dilatation behave differently. Acute obstruction increases peristalsis frequency, producing colic. Chronic dilatation decreases frequency and amplitude; the ureter becomes a passive conduit. This is why long-standing hydroureter does not recover contractile function after timely decompression, and is the structural basis for the "decompensated megaureter."
  • Peristalsis depends on L-type calcium channels. Nifedipine blocks action potential, calcium transient, and contraction — relevant clinically only as a footnote for medical expulsive therapy of distal stones.[5]
  • Stents eliminate peristalsis across the stented segment. Urine drains around and through the stent by bulk flow, not propulsion, which is part of why a stented ureter tolerates kinks and why stent removal sometimes uncovers functionally impaired segments.

The Ureterovesical Junction and Anti-reflux Mechanism​

The UVJ is a passive valve, not a sphincter. Its competence depends on three features, any of which can be disrupted by disease or surgery:[1][2]

  1. Oblique intramural course — ~1.5–2 cm of submucosal tunnel that is compressed by rising intravesical pressure (flap-valve principle). A short submucosal tunnel is the mechanical basis of primary VUR and informs the 5 : 1 tunnel-length-to-ureteral-diameter ratio targeted in reimplantation.
  2. Detrusor backing — the ureter lies between mucosa and detrusor so filling pressure closes the tunnel against its muscular floor.
  3. Trigonal continuity — the longitudinal ureteral muscle continues as the superficial trigone and deep trigone, anchoring the orifice and maintaining tunnel geometry.

Surgical implications:

  • Any reimplantation (Lich-Gregoir, Cohen cross-trigonal, Politano-Leadbetter, ureteroneocystostomy with Psoas hitch / Boari flap) must recreate adequate submucosal length on a well-vascularized detrusor backing.
  • Loss of trigonal continuity (radical cystectomy with neobladder, extensive trigone resection) removes the native mechanism; refluxing ureteral anastomoses to ileal/colonic reservoirs rely on low reservoir pressure rather than a true valve.

Clinical Correlations for the Reconstructive Urologist​

  • Three physiologic narrowings and stone impaction. The ureter is narrowest at the UPJ, at the crossing of the iliac vessels, and at the UVJ — the three sites where stones lodge.
  • Iatrogenic injury prevention is anatomy, not force. The surgical rules — positive identification before ligation, mobilization only with adventitia intact, approach opposite the blood supply, and intraoperative stenting when the plane is obscure — are derived directly from the segmental anatomy above.
  • Long-segment defects: length + vascularity. Reconstruction strategy is driven first by length of defect and second by preserved blood supply. Primary ureteroureterostomy tolerates small defects; Boari flap and Psoas hitch extend the distal ureter; ileal ureter replaces long losses; renal autotransplantation is the last territory before diversion. Preserving the adventitia at the cut edges preserves the option space.
  • Megaureter and post-obstructive dilation. Chronic dilation reduces contractile amplitude and coordination; tapering and re-implantation can re-establish effective peristalsis across an ectatic distal segment, but a decompensated proximal ureter may not regain function even after a competent reimplant.
  • Vesicoureteral reflux and the 5 : 1 rule. Anti-reflux competence depends on adequate submucosal tunnel length relative to ureteral diameter; reconstructive techniques aim for a 5 : 1 tunnel-length-to-diameter ratio.
  • Denervation tolerance. Because peristalsis is myogenic, extensive ureteral mobilization and transposition can be tolerated functionally — if the adventitial blood supply is respected.
  • Sex-specific relations. In women the cardinal ligament / uterine artery crossing is the iatrogenic injury site; in men the vas-deferens crossing is the most often cited distal relation and is involved during vasectomy, inguinal herniorrhaphy, and prostatic surgery.

Videos​

Ureter anatomy
Course, relations, and surgical landmarks

References​

1. Bohnenpoll T, Kispert A. "Ureter Growth and Differentiation." Semin Cell Dev Biol. 2014;36:21–30. doi:10.1016/j.semcdb.2014.07.014

2. Bhargava P, Dighe MK, Lee JH, Wang C. "Multimodality Imaging of Ureteric Disease." Radiol Clin North Am. 2012;50(2):271–299. doi:10.1016/j.rcl.2012.02.008

3. Hanna MK, Jeffs RD, Sturgess JM, Barkin M. "Ureteral Structure and Ultrastructure. Part I. The Normal Human Ureter." J Urol. 1976;116(6):718–724. doi:10.1016/s0022-5347(17)58986-7

4. Bohnenpoll T, Feraric S, Nattkemper M, et al. "Diversification of Cell Lineages in Ureter Development." J Am Soc Nephrol. 2017;28(6):1792–1801. doi:10.1681/ASN.2016080849

5. Burdyga T, Lang RJ. "Excitation-Contraction Coupling in Ureteric Smooth Muscle: Mechanisms Driving Ureteric Peristalsis." Adv Exp Med Biol. 2019;1124:103–119. doi:10.1007/978-981-13-5895-1_4

6. Hurtado R, Bub G, Herzlinger D. "The Pelvis-Kidney Junction Contains HCN3, a Hyperpolarization-Activated Cation Channel That Triggers Ureter Peristalsis." Kidney Int. 2010;77(6):500–508. doi:10.1038/ki.2009.483

7. Lang RJ, Hashitani H. "Pacemaker Mechanisms Driving Pyeloureteric Peristalsis: Modulatory Role of Interstitial Cells." Adv Exp Med Biol. 2019;1124:77–101. doi:10.1007/978-981-13-5895-1_3

8. Zaitouna M, Alsaid B, Lebacle C, et al. "Origin and Nature of Pelvic Ureter Innervation." Neurourol Urodyn. 2017;36(2):271–279. doi:10.1002/nau.22919

9. Vernez SL, Okhunov Z, Wikenheiser J, et al. "Precise Characterization and 3-Dimensional Reconstruction of the Autonomic Nerve Distribution of the Human Ureter." J Urol. 2017;197(3 Pt 1):723–729. doi:10.1016/j.juro.2016.08.118

10. Nemeth L, O'Briain DS, Puri P. "Demonstration of Neuronal Networks in the Human Upper Urinary Tract Using Confocal Laser Scanning Microscopy." J Urol. 2001;166(1):255–258.