Hydronephrosis

Dilation of the renal pelvis and calyces caused by the backward pressure of trapped urine.

Etiology

Mechanical:

+ Congenital

+ Acquired:

• Intrinsic: trauma, inflammation and bleeding, calculi, urologic neoplasms, BPH, urethral stricture, phimosis
• Extrinsic: trauma, neoplasms (uterine fibroid; colorectal, uterine, and cervical malignancies; lymphoma), aortic aneurysm

+ Functional:

• Neurogenic: neurogenic bladder, diabetic neuropathy, spinal cord disease
• Pharmacologic: anticholinergics, a-adrenergic agonists
• Hormonal: pregnancy can cause hydronephrosis due to hormonal effects on ureteral tone and mechanical pressure

Investigations

• Focused history, inquiring about pain (flank, lower abdomen, testes, labia), urine output, medication use, pregnancy, trauma, fever, history ofUTis, calculi and pelvic inflammatory disease (PID)
• CBC, electrolytes, Cr, BUN, urine R&M, C&S
• Imaging studies (ultrasound is >90% sensitive and specific for hydronephrosis)

Treatment

• • Treatment depends on cause, and aims to relieve the cause of obstruction/stasis
  • Urgent treatment is required if associated with infection, acute renal failure, or severe pain

• Percutaneous nephrostomy tube or ureteral stenting to relieve pressure