What Is It, Causes, Treatment, and More

Author:Anna Hernández, MD

Editors:Alyssa Haag,Ian Mannarino, MD, MBA,Kelsey LaFayette, DNP, RN, FNP-C

Illustrator:Jessica Reynolds, MS

Copyeditor:Stacy L. Johnson, LMSW

What is ureterectasis?

Ureterectasis refers to the dilation of one or both ureters, which are the fibromuscular tubes that carry urine from the renal pelvis of the kidney to the urinary bladder. If there is an obstruction to the flow of urine, it can cause pressures in the ureters to increase, thereby causing dilation. With dilation of just the ureter, it is called ureterectasis, or hydroureter. If there is dilation of the ureter and respective kidney, it is called hydroureteronephrosis or hydronephrosis.

Two kidneys and ureters, on with dilation and back-up of urine into the kidney.

What causes ureterectasis?

Causes of ureterectasis can be divided into congenital and acquired. Congenital causes include UPJ, or ureteropelvic junction obstruction, where the ureteropelvic junction (i.e., the area that connects the ureter to the kidney) fails to canalize during fetal development, obstructing the flow of urine. Another congenital cause is vesicoureteral reflux, where urine flows backward from the bladder into the ureters and, eventually, the kidneys. Congenital causes also include posterior urethral valves, where the posterior urethra, which is the section of the urethra nearest to the bladder, is obstructed by flaps of tissue. On the other hand, acquired causes of ureterectasis include kidney stones, prostatic hyperplasia (i.e., enlarged prostate), and external compression of the ureter by retroperitoneal or pelvic tumors.

Excited Mo character in scrubs
Join millions of students and clinicians who learn by Osmosis!
Start Your Free Trial

How is ureterectasis diagnosed & treated?

Often, ureterectasis is asymptomatic and discovered incidentally on an ultrasound or other imaging techniques (e.g., CT scan). Nonetheless, urinary tract obstruction may cause flank pain, groin pain, or decreased urine output. If kidney stones are the cause, blood in the urine may be observed. In addition, urinary stasis may allow bacteria to enter the urinary tract and cause a urinary tract infection, which may be associated with symptoms such as fever, chills, malaise, or dysuria. Over time, recurring infections and kidney injury can lead to chronic kidney disease, which might progress to end-stage renal disease, if left untreated. 

Ureterectasis treatment aims to relieve the obstruction and allow the urine, that may have accumulated behind the obstruction, to flow out. In cases of ureteropelvic junction obstruction, treatment may involve a pyeloplasty, a surgical remake of the renal pelvis. In the case of posterior urethral valves, treatment may involve surgery and ablation of the membrane of tissue, which allows urine to flow through unobstructed. Lower urinary tract obstructions, like kidney stones, may be treated with shockwave lithotripsy or surgery and stent placement. Finally, prostatic hyperplasia can be treated by inserting a urinary catheter to keep the urethra open or a suprapubic catheter to allow bladder decompression.

Watch related videos:

Mo with coat and stethoscope

Want to Join Osmosis?

Join millions of students and clinicians who learn by Osmosis!

Start Your Free Trial

Related links

Anatomy of the abdominal viscera: Kidneys, ureters, and suprarenal glands

Resources for research and reference

Clinical manifestations and diagnosis of urinary tract obstruction and hydronephrosis. (n.d.). Retrieved May 4, 2022, from 

Thotakura R, Anjum F. Hydronephrosis And Hydroureter. [Updated 2021 Dec 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:

Clinical presentation and diagnosis of posterior urethral valves. (n.d.). Retrieved May 4, 2022, from