UrologySchool.com

CUA: Antenatal hydronephrosis (2017): Difference between revisions

← Older edit
Visual
 
(32 intermediate revisions by the same user not shown)
Line 43: Line 43:


=== Hydronephrosis ===
=== Hydronephrosis ===
*'''Various grading systems for the severity of antenatal hydronephrosis exist (3):'''
*'''Grading systems for the severity of antenatal hydronephrosis (3):'''
*# '''Antero-posterior renal pelvic diameter (APD)'''
*# '''Antero-posterior renal pelvic diameter (APD)'''
*#'''Society of Fetal Ultrasound (SFU) classification'''
*#'''Society of Fetal Ultrasound (SFU) classification'''
Line 106: Line 106:
== Antenatal vs. post-natal follow-up ==
== Antenatal vs. post-natal follow-up ==


* '''The frequency of antenatal follow-up of a pregnant mother is left to the discretion of the obstetrician.'''
* '''Frequency of antenatal follow-up of a pregnant mother is at the discretion of the obstetrician'''
* '''Second trimester antenatal hydronephrosis is often followed up so that progression of severity can be detected and appropriate postnatal follow-up planned'''
* '''<span style="color:#ff0000">Second trimester antenatal hydronephrosis is often followed up so that progression of severity can be detected and appropriate postnatal follow-up planned'''
* '''Most centres define significant antenatal hydronephrosis in the third trimester as APD ≥7 mm'''
* '''<span style="color:#ff0000">Most centers define significant antenatal hydronephrosis in the third trimester as APD ≥7 mm'''
** Although APD >4‒5 mm in the third trimester is considered pyelectasis, the ideal cut-off for routine postnatal screening remains controversial, since high grades of AHN can resolve postnatally and conversely low grades can deteriorate
** Although APD >4‒5 mm in the third trimester is considered pyelectasis, the ideal cut-off for routine postnatal screening remains controversial, since high grades of AHN can resolve postnatally and conversely low grades can deteriorate
* '''Indications for referral to a pediatric urologist for antenatal counselling (5):'''
* '''<span style="color:#ff0000">Indications for referral to a pediatric urologist for antenatal counselling'''
*# '''Dilated bladder'''
**'''<span style="color:#ff0000">If antenatal fetal ultrasound (5):'''
*# '''History of oligohydramnios'''
**# '''<span style="color:#ff0000">Dilated bladder'''
*# '''Severe bilateral hydronephrosis'''
**# '''<span style="color:#ff0000">History of oligohydramnios'''
*# '''Increased renal cortical echogenicity''' (hyper-echogenicity)
**# '''<span style="color:#ff0000">Severe bilateral hydronephrosis'''
*# '''Renal cortical cysts'''
**# '''<span style="color:#ff0000">Increased renal cortical echogenicity''' (hyper-echogenicity)
** '''These findings raise concern for potential renal failure'''
**# '''<span style="color:#ff0000">Renal cortical cysts'''
* While AHN is more common in fetuses with serious chromosomal anomalies, '''routine karyotyping for all cases of isolated AHN is not recommend'''. However, this may be considered in the presence of multiple system anomalies.
*** '''<span style="color:#ff0000">These findings raise concern for potential renal failure'''
* '''Karyotype'''
**'''Routine karyotyping for all cases of isolated antenatal hydronephrosis is not recommend'''
***May be considered in the presence of multiple system anomalies.
****Antenatal hydronephrosis is more common in fetuses with serious chromosomal anomalies


== Postnatal Diagnosis and Evaluation ==
== Postnatal Diagnosis and Evaluation ==


=== '''UrologySchool.com Summary''' ===
=== UrologySchool.com Summary ===


* '''History and Physical Exam'''
* '''<span style="color:#ff0000">History and Physical Exam'''
* '''Labs'''
* '''<span style="color:#ff0000">Labs'''
** '''Urinalysis'''
** '''<span style="color:#ff0000">Urinalysis'''
** '''+/- serum creatinine'''
** '''<span style="color:#ff0000">+/- serum creatinine'''
* '''Imaging'''
* '''<span style="color:#ff0000">Imaging'''
** '''Renal-bladder ultrasound (to evaluate for renal injury)'''
** '''<span style="color:#ff0000">Renal-bladder ultrasound (to evaluate for renal injury)'''
** '''+/- VCUG or Nuclear Cystography (to rule out VUR)'''
** '''<span style="color:#ff0000">+/- VCUG or Nuclear Cystography (to rule out VUR)'''
** '''+/- Nuclear Renography'''
** '''<span style="color:#ff0000">+/- Nuclear Renography'''


=== '''History and Physical Exam''' ===
=== History and Physical Exam ===
* '''Physical Exam'''
* '''<span style="color:#ff0000">Physical Exam'''
*#'''Presence of a palpable kidney or bladder'''
*#'''<span style="color:#ff0000">Presence of a palpable kidney or bladder'''
*#'''Abdominal wall abnormality'''
*#'''<span style="color:#ff0000">Abdominal wall abnormality'''
*#'''Signs of spina bifida occulta'''
*#'''<span style="color:#ff0000">Signs of spina bifida occulta'''
*#'''Normal introitus in females'''
*#'''<span style="color:#ff0000">Normal introitus in females'''
*#'''Presence of testicles and a normal urethra in males'''
*#'''<span style="color:#ff0000">Presence of testicles and a normal urethra in males'''


=== '''Labs''' ===
=== Labs ===
* '''Baseline urinalysis'''
* '''Baseline urinalysis'''
** Can be useful in the infant follow-up period and when the child is non-verbal and unable to express symptoms of a UTI, although the need for bag specimens introduces a high risk of contamination.
** Can be useful in the infant follow-up period and when the child is non-verbal and unable to express symptoms of a UTI, although the need for bag specimens introduces a high risk of contamination.
* '''Serum creatinine'''
* '''Serum creatinine'''
** '''Indications (3):'''
** '''<span style="color:#ff0000">Indications (3):'''
**# '''Severe bilateral HN'''
**# '''<span style="color:#ff0000">Severe bilateral HN'''
**# '''Abnormal renal echogenicity'''
**# '''<span style="color:#ff0000">Abnormal renal echogenicity'''
**# '''Solitary kidney'''
**# '''<span style="color:#ff0000">Solitary kidney'''
** '''Should be obtained after 2 days to avoid confusion with maternal creatinine.'''
** '''<span style="color:#ff0000">Should be obtained after 2 days to avoid confusion with maternal creatinine.'''
'''Imaging'''
 
* '''Renal-bladder US (RBUS)'''
=== Imaging ===
** '''Verbatim (summary section): All significant AHN should be investigated with a postnatal RBUS. Most centres define significant AHN in the third trimester as APD ≥7 mm'''
 
*** ''Verbatim (RBUS section): All children with AHN should have a complete abdominopelvic US, with particular attention to both the kidneys and bladder. [likely meant “significant” ANH rather than "all" patients]''
==== Renal-bladder US (RBUS) ====
** The RBUS should include assessment of cranio-caudal length of the kidneys, degree of echogenicity and corticomedullary differentiation, SFU grade of hydronephrosis, maximal APD on transverse axial view of the renal pelvis, diameter of both proximal and distal ureter if dilated, the degree of bladder filling, the detrusor thickness or presence of bladder trabeculation, diverticula, ureterocele, and posterior urethral dilation in males.
 
** '''A full bladder should prompt a period of observation with re-imaging post-void to assess for the capability to empty the bladder and to assess whether the HN improves post-void.'''
===== <span style="color:#ff0000">Indications (1) =====
** Fasting for a RBUS is unnecessary.
#'''<span style="color:#ff0000">APD ≥7 mm in third trimester'''
** '''Timing (see below):'''
#*'''<span style="color:#ff0000">Verbatim (summary section): All significant AHN should be investigated with a postnatal RBUS. Most centres define significant AHN in the third trimester as APD ≥7 mm'''
*** '''Avoid US in the first 2 days of life due to concern of understaging secondary to neonatal oliguria.'''
#** ''Verbatim (RBUS section): All children with AHN should have a complete abdominopelvic US, with particular attention to both the kidneys and bladder. [likely meant “significant” ANH rather than "all" patients]''
*** The acceptable delay in the timing of the first postnatal US is controversial, with the SFU suggesting anywhere from 1‒4 weeks (see Figure 1 from Original Guideline for details, discussed below). '''In cases where immediate postnatal management is required such as PUV, US should not be delayed.'''
 
* '''Voiding cysto-urethrography (VCUG) [or nuclear cystography]'''
===== Timing =====
** '''The clinical utility of a VCUG in HGHN is to distinguish an obstructive cause of AHN from one due to VUR, not due to concern over UTI'''
* '''Avoid US in the first 2 days of life due to concern of understaging secondary to neonatal oliguria.'''
*** '''On average, 16% of infants with ANH are found to have VUR, with 25% of such cases occurring in the non-dilated, contralateral renal unit.'''
* The acceptable delay in the timing of the first postnatal US is controversial, with the SFU suggesting anywhere from 1‒4 weeks (see Figure 1 from Original Guideline for details, discussed below). '''In cases where immediate postnatal management is required such as PUV, US should not be delayed.'''
** '''Steps to VCUG'''
 
**# '''A scout view''' for assessment of spine anomalies, presence of significant constipation or urinary stones
===== Technique =====
**# '''Catheter is inserted'''
 
**#* '''A balloon catheter should not be used''', as the balloon can obscure the filling defect characteristic of a ureterocele.
*Fasting for a RBUS is unnecessary.
**#* The amount of urine removed should be recorded and the urine sent for analysis and culture as indicated.
*RBUS should include assessment of
**#* The bladder should be gravity filled until the first void occurs, with recording of the bladder capacity.
**Cranio-caudal length of the kidneys
**# '''Voiding views''' of the urethra with post-void views of the bladder.
**Degree of echogenicity and corticomedullary differentiation
**# '''Delayed imaging''' after the post-void image may be required if there is VUR into a dilated renal pelvis or ureter so as to assess for concomitant UPJO and UVJO
**SFU grade of hydronephrosis
*** '''A cyclical study with at least two fill and void cycles will increase the detection of VUR.'''
**Maximal APD on transverse axial view of the renal pelvis
** '''Nuclear cystography is more sensitive than VCUG for VUR with less radiation exposure'''
**Diameter of both proximal and distal ureter if dilated
** '''Indications'''
**Degree of bladder filling
*** '''The AUA guidelines on VUR similarly recommends that VCUG in the neonate with:'''
**Detrusor thickness or presence of bladder trabeculation
***# '''High-grade (SFU grade ≥3) hydronephrosis'''
**Diverticula
***# '''Hydroureter'''
**Ureterocele
***# '''An abnormal bladder on ultrasound''' (late-term prenatal or postnatal)
**Posterior urethral dilation in males.
***# '''Develop a UTI on observation'''
* '''A full bladder should prompt a period of observation with re-imaging post-void to assess for the capability to empty the bladder and to assess whether the hydronephrosis improves post-void'''
*** '''VCUG is not necessary in the evaluation of isolated LGHN (SFU 1‒2) with normal renal parenchyma and symmetric renal size'''
 
*** '''Any infant with suspected bladder outlet obstruction (e.g., PUV) should have an urgent VCUG. The following should raise suspicious for bladder outlet obstruction (7):'''
==== Voiding cysto-urethrography (VCUG) [or nuclear cystography] ====
***# '''Dilated posterior urethra'''
* '''Goal is to distinguish an obstructive cause of AHN from VUR''', not due to concern over UTI
***# '''Distended bladder'''
** ≈'''16% of infants with ANH are found to have VUR, with 25% of such cases occurring in the non-dilated, contralateral renal unit.'''
***# '''Thick or trabeculated bladder'''
* '''Nuclear cystography is more sensitive than VCUG for VUR with less radiation exposure'''
***# '''History of oligohydramnios'''
 
***# '''Severe bilateral hydronephrosis'''
===== Indications =====
***# '''Increased renal cortical echogenicity''' (hyper-echogenicity)
* '''<span style="color:#ff0000">The AUA guidelines on VUR similarly recommends that VCUG in the neonate with:'''
***# '''Renal cortical cysts'''
*# '''<span style="color:#ff0000">High-grade (SFU grade ≥3) hydronephrosis'''
* '''Diuretic renography'''
*# '''<span style="color:#ff0000">Hydroureter'''
** '''MAG3 diuretic renogram is test of choice for the assessment of the function of a hydronephrotic kidney as it permits assessment of both the differential renal function (DRF) and the drainage time.'''
*# '''<span style="color:#ff0000">An abnormal bladder on ultrasound</span>''' (late-term prenatal or postnatal)
*** A dimercaptosuccinic acid (DMSA) study can be considered to establish early split function in cases of neonates or premature infants, since the DRF in this study is not influenced by an immature GFR.
*# '''<span style="color:#ff0000">Develops a UTI on observation'''
** The diuretic renogram should include a report of the DRF, which can vary from 45‒55%; the cortical transit time, which is normal up to 5 minutes; the half-time; and the shape of the curve.
* '''VCUG is not necessary in the evaluation of isolated LGHN (SFU 1‒2) with normal renal parenchyma and symmetric renal size'''
** '''Test results can be influenced by'''
* '''<span style="color:#ff0000">Any infant with suspected bladder outlet obstruction (e.g., PUV) should have an urgent VCUG.'''  
*** '''Poor renal function (single kidney glomerular filtration rate [GFR] <15 ml/min)'''
**'''<span style="color:#ff0000">Findings associated with bladder outlet obstruction (7):'''
*** '''Poor hydration'''
**# '''<span style="color:#ff0000">Dilated posterior urethra'''
*** '''Massively dilated collecting system'''
**# '''<span style="color:#ff0000">Distended bladder'''
*** '''Full bladder'''
**# '''<span style="color:#ff0000">Thick or trabeculated bladder'''
*** '''Dilated distal ureter'''
**# '''<span style="color:#ff0000">History of oligohydramnios'''
** Renograms can be performed at any age, as long as they are used as a baseline study for serial comparison'''.'''
**# '''<span style="color:#ff0000">Severe bilateral hydronephrosis'''
** '''Indications'''
**# '''<span style="color:#ff0000">Increased renal cortical echogenicity''' (hyper-echogenicity)
*** '''APD >15 mm or HGHN (SFU 3-4) with VCUG was negative for VUR''' to identify other potential causes of hydronephrosis (such as UPJO, UVJO)
**# '''<span style="color:#ff0000">Renal cortical cysts'''
*** '''Not necessary in the evaluation of isolated LGHN (SFU 1‒2) with normal renal parenchyma and symmetric renal size'''
 
'''Other'''
===== Technique =====
 
*'''Steps by step'''
*# '''A scout view''' for assessment of spine anomalies, presence of significant constipation or urinary stones
*# '''Catheter is inserted'''
*#* '''A balloon catheter should not be used''', as the balloon can obscure the filling defect characteristic of a ureterocele.
*#* The amount of urine removed should be recorded and the urine sent for analysis and culture as indicated.
*#* The bladder should be gravity filled until the first void occurs, with recording of the bladder capacity.
*# '''Voiding views''' of the urethra with post-void views of the bladder.
*# '''Delayed imaging''' after the post-void image may be required if there is VUR into a dilated renal pelvis or ureter so as to assess for concomitant UPJO and UVJO
** '''A cyclical study with at least two fill and void cycles will increase the detection of VUR.'''
**#
 
==== Diuretic renography ====
* '''<span style="color:#ff0000">Nuclear tracer'''
**'''<span style="color:#ff0000">MAG3 diuretic renogram is test of choice for the assessment of the function of a hydronephrotic kidney'''
***Permits assessment of both the differential renal function (DRF) and the drainage time
*** Dimercaptosuccinic acid (DMSA) study can be considered to establish early split function in cases of neonates or premature infants, since the DRF in this study is not influenced by an immature GFR.
* '''<span style="color:#ff0000">Indications (1)'''
*# '''<span style="color:#ff0000">APD >15 mm or high-grade hydronephrosis (SFU 3-4) with VCUG was negative for VUR'''  
*#*'''To identify other potential causes of hydronephrosis (such as UPJO, UVJO)'''
**'''Not necessary in the evaluation of isolated LGHN (SFU 1‒2) with normal renal parenchyma and symmetric renal size'''
*Renogram should include a report of
**Differential renal function, which can vary from 45‒55%
**Cortical transit time, which is normal up to 5 minutes
**Half-time
**Shape of the curve
* '''Test results can be influenced by'''
** '''Poor renal function (single kidney glomerular filtration rate [GFR] <15 ml/min)'''
** '''Poor hydration'''
** '''Massively dilated collecting system'''
** '''Full bladder'''
** '''Dilated distal ureter'''
* Renograms can be performed at any age, as long as they are used as a baseline study for serial comparison'''.'''
 
=== Other ===
* Additional studies are sometimes necessary to further elucidate the precise cause of AHN, which, because of their invasive nature, are reserved for only select cases.
* Additional studies are sometimes necessary to further elucidate the precise cause of AHN, which, because of their invasive nature, are reserved for only select cases.
* Percutaneous antegrade pyelography or endoscopic retrograde pyelography can be useful when multiple levels of obstruction are suspected, such as combined UPJO and UVJO.
* Percutaneous antegrade pyelography or endoscopic retrograde pyelography can be useful when multiple levels of obstruction are suspected, such as combined UPJO and UVJO.
Line 209: Line 248:


* '''The role of CAP initiated at birth is controversial'''
* '''The role of CAP initiated at birth is controversial'''
* '''CAP may be of benefit in (4):'''
* '''cCAP may be of benefit in (4):'''
*# '''HGHN (SFU 3-4)'''
*# '''<span style="color:#ff0000">HGHN (SFU 3-4)'''
*# '''Females with ANH'''
*# '''<span style="color:#ff0000">Females with ANH'''
*# '''Uncircumcised males with ANH'''
*# '''<span style="color:#ff0000">Uncircumcised males with ANH'''
*# '''Cases with dilated ureter or bladder abnormality'''
*# '''<span style="color:#ff0000">Cases with dilated ureter or bladder abnormality'''
* '''Commonly used prophylaxes in the neonate include:'''
* '''<span style="color:#ff0000">Commonly used prophylaxes in the neonate include:'''
*# '''Amoxicillin'''
*# '''<span style="color:#ff0000">Amoxicillin'''
*# '''Cephalexin'''
*# '''<span style="color:#ff0000">Cephalexin'''
*# '''Trimethoprim'''
*# '''<span style="color:#ff0000">Trimethoprim'''
** Trimethoprim is contraindicated in premature infants and age <6 weeks (CW12 p442)
** <span style="color:#ff0000">'''Trimethoprim is contraindicated in premature infants and age <6 weeks</span>''' (CW12 p442)
** '''TMP/SMX should NOT be used age <6-8 weeks because of the respective risk of kernicterus.''' (CW12 p443/513)
** '''<span style="color:#ff0000">TMP/SMX should NOT be used age <6-8 weeks because of the respective risk of kernicterus.''' (CW12 p443/513)
** '''Nitrofurantoin should NOT be used age <3 months because of the risk of hemolytic anemia.'''
** '''<span style="color:#ff0000">Nitrofurantoin should NOT be used age <3 months because of the risk of hemolytic anemia.'''


== Follow-up protocols ==
== Follow-up protocols ==
Line 226: Line 265:
* '''Based on severity of hydronephrosis'''
* '''Based on severity of hydronephrosis'''
** '''See [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905549/figure/f1-cuaj-4-85/ Figure 1] from Original Guideline'''
** '''See [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905549/figure/f1-cuaj-4-85/ Figure 1] from Original Guideline'''
** '''High-grade hydronephrosis (SFU Grades 3 and 4) or APD >15 mm'''
*** '''Initial post-natal RBUS'''
**** '''Should be done as soon as feasible after day 2 of life''' (most centres recommend '''within 2 weeks of life''') as this represents the cohort most likely to require surgery and to experience UTI.
**** '''If the postnatal US reveals persistent high-grade hydronephrosis, these cases should be referred to a pediatric urologist for immediate consultation.'''
***** Bilateral HGHN requires more urgent consultation.
*** '''Additional investigations'''
**** '''Patients should have a VCUG'''
***** '''MAG3 renal scan should be done if the VCUG is negative for VUR'''
*** '''These cases are most likely to benefit from CAP'''
*** '''In the absence of any pathology requiring immediate intervention, repeat US and MAG3 should be performed within 3 months,''' although a repeat MAG3 is optional if the first exam is normal. '''If improvement is not seen, close follow-up should continue to at least 18 months of age,''' by which time most childhood UPJO becomes apparent.
** For cases with antenatal APD 10‒15 mm, the SFU grading is suggested to clarify which follow-up protocol should be used
** '''Low-grade hydronephrosis (SFU Grade 1 and 2) or APD <10 mm'''
*** '''Initial post-natal RBUS'''
**** Timing open to debate; '''most physicians will obtain an US within the first months of life and a follow-up can be obtained 6 months later.'''
***** In the absence of deterioration, follow-up US can then be performed on an annual basis.
*** '''Additional investigations'''
**** '''VCUG and MAG3 are not required'''
*** '''CAP is unnecessary'''
*** '''The majority of such cases improve by age 2'''. Since the majority of congenital UPJO progresses to pyeloplasty by 18 months of age, '''continue follow-up to at least until age 2.'''
**** There is controversy on the need for follow-up beyond 2 years of age in patients who have persistent LGHN.
** '''SFU Grade 0'''
*** '''Up to 50% of ANH can resolve at birth and is referred to as SFU Grade 0 HN.'''
*** '''SFU guidelines recommend a repeat US within the first month of life.'''
**** Many centres will discharge the patient after a normal post-natal US, since the majority of late or recurrent HN are symptomatic and can be counselled as such.
*** '''In patients with a history of mild to moderate fetal hydronephrosis and a normal post-partum ultrasound (obtained at 1-2 months), additional evaluations are unnecessary.'''
*** '''In patients with a history of moderate to severe fetal hydronephrosis and a normal post-partum ultrasound, additional evaluations are necessary.'''
**** '''The presence of ureteral dilation on the pre-natal ultrasound has been found to be associated with a significant increased risk for neonatal UTIs and high-grade vesicoureteral reflux despite a normal post-partum renal ultrasound.'''
**** A neonatal VCUG is recommended if ureteral dilation is found on the fetal ultrasound.


== Indications for surgery in obstructive HN and HUN ==
=== High-grade hydronephrosis (SFU Grades 3 and 4) or APD >15 mm on 3rd Trimester Ultrasound ===
* '''<span style="color:#ff0000">Initial post-natal RBUS'''
** '''<span style="color:#ff0000">Should be done as soon as feasible after day 2 of life</span>''' (most centres recommend '''<span style="color:#ff0000">within 2 weeks of life</span>''') as this represents the cohort most likely to require surgery and to experience UTI.
** '''<span style="color:#ff0000">If the postnatal US reveals persistent high-grade hydronephrosis, these cases should be referred to a pediatric urologist for immediate consultation.'''
*** Bilateral HGHN requires more urgent consultation.
* '''<span style="color:#ff0000">Additional investigations'''
** '''<span style="color:#ff0000">Patients should have a VCUG'''
*** '''<span style="color:#ff0000">MAG3 renal scan should be done if the VCUG is negative for VUR'''
* '''<span style="color:#ff0000">These cases are most likely to benefit from CAP'''
* '''<span style="color:#ff0000">In the absence of any pathology requiring immediate intervention, repeat US and MAG3 should be performed within 3 months,</span>''' although a repeat MAG3 is optional if the first exam is normal. '''If improvement is not seen, close follow-up should continue to at least 18 months of age,''' by which time most childhood UPJO becomes apparent.
 
* For cases with antenatal APD 10‒15 mm, the SFU grading is suggested to clarify which follow-up protocol should be used
 
=== Low-grade hydronephrosis (SFU Grade 1 and 2) or APD <10 mm on 3rd Trimester Ultrasound ===
* '''<span style="color:#ff0000">Initial post-natal RBUS'''
** Timing open to debate; '''<span style="color:#ff0000">most physicians will obtain an US within the first months of life and a follow-up can be obtained 6 months later.'''
*** In the absence of deterioration, follow-up US can then be performed on an annual basis.
* '''<span style="color:#ff0000">Additional investigations'''
** '''<span style="color:#ff0000">VCUG and MAG3 are not required'''
* '''<span style="color:#ff0000">CAP is unnecessary'''
* '''The majority of such cases improve by age 2'''. Since the majority of congenital UPJO progresses to pyeloplasty by 18 months of age, '''continue follow-up to at least until age 2.'''
** There is controversy on the need for follow-up beyond 2 years of age in patients who have persistent LGHN.
 
=== SFU Grade 0 ===
* '''Up to 50% of ANH can resolve at birth and is referred to as SFU Grade 0 HN.'''
* '''<span style="color:#ff0000">SFU guidelines recommend a repeat US within the first month of life.'''
** Many centres will discharge the patient after a normal post-natal US, since the majority of late or recurrent HN are symptomatic and can be counselled as such.
**"it appears contradictory to follow up a documented LGHN within six months, whereas a normal US is followed up within one month."
*'''<span style="color:#ff0000">[In patients with a history of mild to moderate fetal hydronephrosis and a normal post-partum ultrasound (obtained at 1-2 months), additional evaluations are unnecessary.]'''
* '''<span style="color:#ff0000">[In patients with a history of moderate to severe fetal hydronephrosis and a normal post-partum ultrasound, additional evaluations are necessary.]'''
** '''The presence of ureteral dilation on the pre-natal ultrasound has been found to be associated with a significant increased risk for neonatal UTIs and high-grade vesicoureteral reflux despite a normal post-partum renal ultrasound.'''
** A neonatal VCUG is recommended if ureteral dilation is found on the fetal ultrasound.
 
== Indications for surgery in Obstructive Hydronephrosis and Hydroureteronephrosis ==


* Appropriate counselling of families should include a discussion of the risks of observation vs. immediate surgery.
* Appropriate counselling of families should include a discussion of the risks of observation vs. immediate surgery.
* '''Strong indications for reconstructive surgery include (2):'''
* '''<span style="color:#ff0000">Strong indications for reconstructive surgery include (2):'''
*# '''Loss of DRF of >5% on serial renography'''
*# '''<span style="color:#ff0000">Loss of differential renal function of >5% on serial renography'''
*# '''Worsening HN with worsening drainage times on renography'''
*# '''<span style="color:#ff0000">Worsening hydronephrosis with worsening drainage times on renography'''
*#* In older children, flank pain or vomiting are also suggestive of obstruction, especially if exacerbated by fluid intake. Hypertension and renal calculi can rarely be signs of obstruction.
*#* In older children, flank pain or vomiting are also suggestive of obstruction, especially if exacerbated by fluid intake. Hypertension and renal calculi can rarely be signs of obstruction.
* '''Relative indications for surgery (5):'''
* '''Relative indications for surgery (5):'''
*# '''UTI'''
*# '''UTI'''
*# '''Low DRF on initial renogram'''
*# '''Low differential renal function on initial renogram'''
*# '''Palpable giant HN'''
*# '''Palpable giant HN'''
*# Concern over '''non-compliance with follow-up imaging protocols'''
*# Concern over '''non-compliance with follow-up imaging protocols'''
Retrieved from "https://urologyschool.com/wikiuro/index.php/CUA:_Antenatal_hydronephrosis_(2017)"