Diagnosis

Hydronephrosis

Dilatation and distension of the renal collecting system due to obstruction of urine outflow distal to the renal pelvis (i.e., ureter, urinary bladder, and urethra). Dilation of the ureter due to obstruction of urine outflow is called hydroureter.

Also known as: Hydroureter, Ureteropelvic junction obstruction

Etiology

Cause [cnk]

Intrinsic obstruction:
- Renal stones (Urolithiasis)
- Blood clots from hematuria
- Ureteropelvic junction stenosis (children)
- Ureteral strictures from prior inflammation (children)
- Urethral valves (children)
- Renal cysts
- Urothelial carcinoma
- Benign prostatic hyperplasia/cancer
- Bladder cancer
- Neurogenic bladder
Extrinsic compression:
- Pregnancy
- Peripelvic cysts
- Retrocaval ureter
- Malignancy
- Trauma
- Retroperitoneal fibrosis
- Prostate abscess
- Pelvic tumors
- Aortic/iliac aneurysm

Pathophysiology [cnk]

Obstruction of urine --> increase in the hydrostatic pressure of the collecting system --> increase in intraglomerular pressure --> affect the glomerular filtration rate
The duration and severity of obstruction determine the extent of loss of kidney function.
Long-lasting obstruction can lead to permanent kidney damage.

Complications [cnk]

Urinary tract infection
Pyelonephritis
Renal failure

Epidemiology

Incidence per 100.000 [o7m][chn][cnk][zhs][h4t][yuy]

Prevalence per 100.000 [o7m][chn][cnk][zhs][h4t][yuy]

Symptoms & findings

Symptoms

Chills, Dysuria, Fever, Hematuria, Nausea, Vomiting

Clinical findings

Elevated Creatinine, Elevated Urea, Hyponatremia

Anamneses

None listed.

Localized findings

Pain

Radiates

Right flankLeft flankInguinalBack

Onset

Subacute (hours)Gradual (days)

Pattern

Constant

Provoked by

Urination

Severity

Mild (1-3)Moderate (4-7)Severe (8-10)

Approach

Blood test
Urine stix
Bladder scan
Abdominal x-ray
Ultrasound abdomen
CT abdomen
Cystoscopy
Voiding cystourethrogram (reflux)

Treatment

Antibiotic prophylaxis
JJ-stent
Urolithiasis: Extracorporeal shockwave lithotripsy, URS
Pyelostomy
Pyeloplasty
Pyelocyststomy
Ureteroneocystostomy
Urinary catheter

Differential diagnoses

Acute renal failure, Chronic renal failure, Pyelonephritis, Renal cyst

References

[1] Thotakura R, Anjum F. Hydronephrosis and Hydroureter. StatPearls Publishing; 2024 Jan: https://www.ncbi.nlm.nih.gov/books/NBK563217/

[2] http://emedicine.medscape.com/article/436259 (2014-01-02); [Medscape]

[3] Sun L, Zhao D, Zhu L, Shen Y, Zhao Y, Tang D. Asymptomatic obstructive hydronephrosis associated with diabetes insipidus: a case report and review. Transl Pediatr. 2021 Jun;10(6):1721-1727.

[4] Bilge I. Symptomatology and Clinic of Hydronephrosis Associated With Uretero Pelvic Junction Anomalies. Front Pediatr. 2020 Sep 30;8:520.

[5] Madden-Fuentes RJ, McNamara ER, Nseyo U, Wiener JS, Routh JC, Ross SS. Resolution rate of isolated low-grade hydronephrosis diagnosed within the first year of life. J Pediatr Urol. 2014 Aug;10(4):639-44.

[6] Akhavan A, Merguerian PA, Larison C, Goldin AB, Shnorhavorian M. Trends in the Rates of Pediatric Pyeloplasty for Ureteropelvic Junction Obstruction over 19 Years: A PHIS Database Study. Adv Urol. 2014;2014:142625.

[7] https://uroweb.org/guidelines/paediatric-urology/chapter/the-guideline

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