Hydronephrosis overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2]
Synonyms and keywords:
Overview
Historical Perspective
Ureteral anatomy and the function of the ureterovesical junction was first discovered by Galen, Leonardo da Vinci and John Sampson.In 1950s, Hodson and Edwards was the first to discover the association between association of VUR with renal scarring.
- Ureteral anatomy and the function of the ureterovesical junction was first discovered by Galen, Leonardo da Vinci drawings and John Sampson dissections.
- In 1950s, Hodson and Edwards was the first to discover the association between association of VUR with renal scarring from bacterial infection and the development of hydronephrosis.
- In 1952, Hutch performed the first antireflux surgery in paraplegic patients.
- In 1717, the first to description of obstruction of the posterior urethra (PUO) was by Morgagni.
Classification
| Grade 0 | No renal pelvis dilation | Anteroposterior diameter of less than 4 mm in fetuses |
| Grade 1 | Mild renal pelvis dilation | Anteroposterior diameter less than 10 mm in fetuses |
| Grade 2 | Moderate renal pelvis dilation | Anteroposterior diameter between 10 and 15 mm in fetuses |
| Grade 3 | Renal pelvis dilation along with all calyces dilatation | |
| Grade 4 | Renal pelvis dilation along with all calyces dilatation
with thinning of the renal parenchyma |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vamsikrishna Gunnam M.B.B.S [2]
Overview
According to the society of Fetal Urology, hydronephrosis may be graded based on ultrasound findings into 4 types.
Classification
- According to the society of Fetal Urology and alternative hydronephrosis grading system (AGS), hydronephrosis can be graded based on ultrasound findings into 4 types.[1][2][3][4][5][6]
| Grade 0 | No renal pelvis dilation | Anteroposterior diameter of less than 4 mm in fetuses |
| Grade 1 | Mild renal pelvis dilation | Anteroposterior diameter less than 10 mm in fetuses |
| Grade 2 | Moderate renal pelvis dilation | Anteroposterior diameter between 10 and 15 mm in fetuses |
| Grade 3 | Renal pelvis dilation along with all calyces dilatation | |
| Grade 4 | Renal pelvis dilation along with all calyces dilatation
with thinning of the renal parenchyma |
References
- ↑ Belarmino JM, Kogan BA (January 2006). “Management of neonatal hydronephrosis”. Early Hum. Dev. 82 (1): 9–14. doi:10.1016/j.earlhumdev.2005.11.004. PMID 16427220.
- ↑ Emamian SA, Nielsen MB, Pedersen JF, Ytte L (September 1993). “Sonographic evaluation of renal appearance in 665 adult volunteers. Correlation with age and obesity”. Acta Radiol. 34 (5): 482–5. PMID 8369185.
- ↑ Kadioglu A (February 2010). “Renal measurements, including length, parenchymal thickness, and medullary pyramid thickness, in healthy children: what are the normative ultrasound values?”. AJR Am J Roentgenol. 194 (2): 509–15. doi:10.2214/AJR.09.2986. PMID 20093617.
- ↑ Huntington DK, Hill SC, Hill MC (August 1991). “Sonographic manifestations of medical renal disease”. Semin. Ultrasound CT MR. 12 (4): 290–307. PMID 1892691.
- ↑ Konda R, Sakai K, Ota S, Abe Y, Hatakeyama T, Orikasa S (May 2002). “Ultrasound grade of hydronephrosis and severity of renal cortical damage on 99m technetium dimercaptosuccinic acid renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty”. J. Urol. 167 (5): 2159–63. PMID 11956470.
- ↑ Onen A (June 2007). “An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guidelines in neonates with primary UPJ-type hydronephrosis”. J Pediatr Urol. 3 (3): 200–5. doi:10.1016/j.jpurol.2006.08.002. PMID 18947735.
Pathophysiology
Hydronephrosis can result from anatomic or functional processes interrupting the flow of urine. This interruption can occur anywhere along the urinary tract from the kidneys to the urethral meatus. The rise in ureteral pressure leads to marked changes in glomerular filtration, tubular function, and renal blood flow. The glomerular filtration rate (GFR) declines significantly within hours following acute obstruction. This significant decline of GFR can persist for weeks after relief of obstruction. In addition, renal tubular ability to transport sodium, potassium, and protons and concentrate and to dilute the urine is severely impaired.
Causes
Hydronephrosis is commonly caused by conditions that obstruct urine outflow anywhere between kidneys and urethral opening. It is also caused by non obstructive conditions in some cases. Most common causes of hydronephrosis are renal calculi, ureteropelvic junction obstruction, vesicoureteric reflux, carcinoma involving urinary tract, prostate enlargement and cancer, blood clots retention and external compression from pelvic and abdominal tumors such as ovarian cysts, and retroperitoneal fibrosis.
Differentiating Hydronephrosis from other Diseases
Hydronephrosis must be differentiated from parapelvic cyst, renal sinus lymphangiectasia, pyelonephritis, cystitis, ovarian cyst, pelvic tumor
Epidemiology and Demographics
The incidence and prevalence of hydronephrosis varies according to the underlying cause. Case fatality rate of hydronephrosis is 3.1 per 100 000 individuals.
Risk Factors
Common risk factors in the development of hydronephrosis include renal calculi, external compression from abdominal and pelvic masses and tumors such as prostate enlargement and cancer, cervical cancer, diabetes mellitus and neurogenic bladder, congenital anomalies of the kidney and urinary tract (CAKUT) such as vesicoureteric reflux, ureteropelvic junction obstruction and posterior urethral valves.
Screening
There is insufficient evidence to recommend routine screening for hydronephrosis.
Natural History, Complications and Prognosis
Common complications of hydronephrosis include infections, hyperkalemia, metabolic acidosis, and distal renal tubular acidosis, hypertension and renal failure.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2]
Overview
Common complications of hydronephrosis include infections, hyperkalemia, metabolic acidosis, and distal renal tubular acidosis, hypertension and renal failure.
Natural History, Complications, and Prognosis
Natural History
- The symptoms of hydronephrosis can usually develop at any age depending on the underlying cause and present with symptoms such as, flank pain/abdominal pain, nausea, vomiting, burning and painful micturition, incomplete voiding.[1]
- If left untreated for several weeks, the kidneys may become scarred, leading to kidney failure.
Complications
Common complications of hydronephrosis include:[2][3][4][5][6]
- Infection secondary to obstruction
- Electrolyte imbalance
- Hyperkalemia
- Metabolic acidosis
- Distal renal tubular acidosis
- Excessive free water diuresis
- Hypertension
- Renal insufficiency and renal failure
Prognosis
- Prognosis is generally good with early treatment. Approximately 95% patients recover with timely intervention.[7][8]
References
- ↑ Sarhan OM, El Helaly A, Al Otay AH, Al Ghanbar M, Nakshabandi Z (March 2018). “Prenatally detected, unilateral, high-grade hydronephrosis: Can we predict the natural history?”. Can Urol Assoc J. 12 (3): E137–E141. doi:10.5489/cuaj.4587. PMC 5869039. PMID 29283090.
- ↑ Kozeny GA, Hurley RM, Vertuno LL, Bansal VK, Zeller WP, Hano JE (1986). “Hypertension, mineralocorticoid-resistant hyperkalemia, and hyperchloremic acidosis in an infant with obstructive uropathy”. Am. J. Nephrol. 6 (6): 476–81. doi:10.1159/000167258. PMID 3565506.
- ↑ Chandar J, Abitbol C, Zilleruelo G, Gosalbez R, Montané B, Strauss J (February 1996). “Renal tubular abnormalities in infants with hydronephrosis”. J. Urol. 155 (2): 660–3. PMID 8558697.
- ↑ Lee JH, Choi HS, Kim JK, Won HS, Kim KS, Moon DH, Cho KS, Park YS (April 2008). “Nonrefluxing neonatal hydronephrosis and the risk of urinary tract infection”. J. Urol. 179 (4): 1524–8. doi:10.1016/j.juro.2007.11.090. PMID 18295269.
- ↑ King LR, Kazmi SO, Belman AB (October 1974). “Natural history of vesicoureteral reflux. Outcome of a trial of nonoperative therapy”. Urol. Clin. North Am. 1 (3): 441–55. PMID 4610948.
- ↑ Mesrobian HG (September 2010). “Urinary proteome analysis and the management of ureteropelvic junction obstruction”. Pediatr. Nephrol. 25 (9): 1595–6. doi:10.1007/s00467-010-1521-2. PMID 20407913.
- ↑ Perlman S, Roitman L, Lotan D, Kivilevitch Z, Pode-Shakked N, Pode-Shakked B, Achiron R, Dekel B, Gilboa Y (February 2018). “Severe fetal hydronephrosis: the added value of associated congenital anomalies of the kidneys and urinary tract (CAKUT) in the prediction of postnatal outcome”. Prenat. Diagn. 38 (3): 179–183. doi:10.1002/pd.5206. PMID 29314159.
- ↑ Renda R (April 2018). “Renal outcome of congenital anomalies of the kidney and urinary tract system: a single-center retrospective study”. Minerva Urol Nefrol. 70 (2): 218–225. doi:10.23736/S0393-2249.17.03034-X. PMID 29161808.
Diagnosis
Diagnosis
Diagnostic study of choice
Early diagnosis of hydronephrosis is important because most of the cases can be reversed if not treated promptly lead to irreversible renal injury.Hydronephrosis is usually diagnosed using an ultrasound scan.
History and symptoms
The majority of patients with hydronephrosis are asymptomatic.The most common symptoms of hydronephrosis include alteration in urine output, pain, hematuria and hypertension.
Physical examination
Patients with hydronephrosiscomplain presence of pain based on the site of the obstruction and the degree of the obstruction. Patients commonly present with abdominal distension, palpable kidney, costovertebral tenderness and palpable bladder may be seen.
Lab findings
Some patients with hydronephrosis may have elevated WBC count, serum creatinine, BUN, potassium levels and pyuria.
EKG
- There are no EKG findings associated with hydronephrosis
X-ray
An x-ray may be helpful in the diagnosis of hydronephrosis. Findings on an x-ray suggestive of hydronephrosis include renal enlargement, cortical thinning and rim sigh.
Echocardiogram and Ultrasound
Early diagnosis of hydronephrosis is important because most of the cases can be reversed if not treated promptly lead to irreversible renal injury.Hydronephrosis is usually diagnosed using an ultrasound scan.
CT scan
Abdominal CT scan may be helpful in the diagnosis of hydronephrosis. Findings on CT scan suggestive of hydronephrosis include dilation of the proximal ureter, identification of the site of obstruction and calyceal blunting.
MRI
Abdomen MRI may be helpful in the diagnosis of hydronephrosis. Findings on MRI suggestive of hydronephrosis include renal perfusion and renal diffusion during acute ureteral obstruction.
Other Imaging findings
There are no other imaging findings associated with hydronephrosis.
Other diagnostic studies
There are no other diagnostic studies associated with hydronephrosis.
Treatment
Treatment
Medical therapy
The goal of treatment for hydronephrosis is to restart the free flow of urine from the kidney and decrease the swelling and pressure that builds up and decreases kidney function.The initial care for the patient is aimed at minimizing pain and preventing urinary tract infections. Otherwise, surgical intervention may be required.
Surgery
- Surgery is the mainstay of treatment for Hydronephrosis. The type of surgery depends on the underlying cause and also depending on whether the obstruction is acute or chronic.
Primary prevention
There are no established measures for the primary prevention of hydronephrosis
Secondary prevention
There are no established measures for the secondary prevention of hydronephrosis
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