Hydroureter

An abnormal dilatation and distension of the ureter with urine, typically resulting from obstruction of urinary outflow between the renal pelvis and the bladder, often occurring together with dilation of the renal collecting system.

Causes

• Obstructive urinary tract causes

  • Urolithiasis

  • Ureteral strictures

  • Blood clots obstructing the ureter

• Lower urinary tract and prostate-related causes

  • Benign prostatic hyperplasia (BPH)

  • Bladder outlet obstruction

  • Neurogenic bladder causing impaired urine drainage

• Pregnancy-related causes

  • Mechanical compression of the ureters by the enlarging uterus

  • Hormonal relaxation of ureteral smooth muscle

• Malignant causes

  • Bladder cancer

  • Uterine cancer

  • Prostate cancer

  • Other pelvic malignancies compressing or invading the ureter

• Vesicoureteral reflux

• Congenital defects of ureter development

• Retroperitoneal fibrosis

• Pelvic inflammatory disease

• Postoperative injury or fibrosis affecting ureteral drainage