Docstoc

clapham

Document Sample
clapham Powered By Docstoc
					 Prenatal and Postnatal
Assessment of Posterior
     Urethral Valve
Katie Rose Clapham, HMS Year III
      Gillian Lieberman, MD
            July 19, 2010
                   Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract malformations
• Case of posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
             Development of the Kidney
Part of       Appears    Functional       Gives rise to
kidney
Pronephros    4th week   Never            Pronephric
                         functional       ducts used by
                                          mesonephros


Mesonephros   4th week   Functions for    Contributes to
                         4 weeks          male genital
                                          structures and
                                          bladder

Metanephros   5th week   Starts           UG bud gives
                         functioning at   rise to ureters
                         9th week         and collecting
                                          ducts
                                          Metanephric
                                          blastema
                                          gives rise to
                                          the rest of the   Image from UpToDate. Overview of CAKUT.
                                          kidney            Waters, A. and Rosenblum, N.
                                                            http://www.uptodate.com/online/content/topic.do
                                                            ?topicKey=pedineph/18797&selectedTitle=1%7
Urogenital                                Bladder and       E150&source=search_result. 7/15/10.
(UG) Sinus                                urethra
          Development of Urethra
•   Mesonephric (Wolffian) duct fuses with UG sinus and
    contributes to urethra
•   Caudal UG sinus (genital tubercle) forms phallic urethra
•   Urethra formation is complete by 14 weeks




                 Image from Lawrentschuk N., and Frydenberg M. Benign Prostate Disorders.
                 Endotext. http://www.endotext.org/male/male9/male9.html. Accessed [7/18/10]
                   Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract malformations
• Case of posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
 Normal Fetal Kidney on Ultrasound

•Cannot reliably see fetal kidney on ultrasound
during 1st trimester.
•Visualized by 16-22 weeks.
•Can visualize cortex and pyramids by 23-26
weeks, and fine anatomy by 30 weeks.
•Fetal kidney length in mm is roughly equal to
the fetal menstrual age in weeks.
      Normal Fetal Bladder on Ultrasound
                   (18 wks)



                                          *




              Transverse View

                                Bladder


PACS, BIDMC
                Normal Fetal Kidney on
                 Ultrasound (18 wks)


                                    *



                                *




              Transverse View
                                Spine
                                Kidneys
PACS, BIDMC
Ultrasound Evaluation of Kidney
           Function
• Fetal kidney function is assessed by
  -visualization of urine in the bladder by 13-
  16 weeks (the ureters are not normally
  seen)
  - measurement of amniotic fluid
  (subjective measures appear to be as
  good as summing the depth of amniotic
  fluid pockets in four quadrants)
                  Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract
  malformations
• Case of posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
                 Types of Kidney Malformations:
                          Parenchymal
                                                         •Hypoplasia

    Gross Hypoplastic Kidney
                                                         •Dysplasia
Massey, H.D. Lab I.j Congenital Malformations. Renal
Pathology for Medical II Students.
http://www.pathology.vcu.edu/education/renal/lab1.j.ht
ml. Accessed [7/15/10].
                                                         •Renal agenesis

      •Multicystic kidney
      •Genetic cystic disease
      (ARPKD, ADPKD, NPH)
                                                                       Multicystic Kidney
                                                                        on Ultrasound
                                                                           PACS, BIDMC
      Types of Kidney Malformations:
                 Migration
• Ectopia
• Fusion



                                                           Crossed Fused Ectopic Kidney
                                                                on CT with contrast
                                                                     PACS, BIDMC




       Horseshoe Kidney on IVU
Irshad, A, Ackerman, S., Ravenel, J.G. Horseshoe Kidney.
http://emedicine.medscape.com/article/378396-overview.
Accessed [7/15/10].
    Types of Kidney Malformations:
          Collecting System
•   Pelvis: UPJ obstruction
•   Ureter: megaureter, ectopic ureter, VUR
•   Bladder: exstrophy
•   Urethra: posterior urethral valve
    (PUV)



                        Ectopic ureter on CT
                        PACS, BIDMC
                   Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract malformations
• Posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
 Patient 1: Posterior Urethral Valve
• Congenital defect
• Affects males
• The ‘valve’ is a membranous fold between
  urethral wall and verumontanum (crest
  where seminal vesicles enter urethra) that
  obstructs the urethra
        Patient 1: Posterior Urethral
                    Valve         Hydronephrotic
Site of membranous ‘valve’                               Gross Appearance                              kidney




                                   Prostate
                                                                                                          Dilated
                                                                                                          ureter


 Image from Lawrentschuk N., and Frydenberg M. Benign
 Prostate Disorders. Endotext.
 http://www.endotext.org/male/male9/male9.html.                                                            Dilated
 Accessed [7/18/10]
                                                        Image from Belman, A., King, L.R., and
                                                        Kramer, S.A. Clinical pediatric urology. 4th
                                                                                                           bladder
                                                        edition. London, England: Martin Dunitz
                                                        Ltd; 2002.



                               The valve may originate from incomplete
                              canalization or an aberrant insertion of the
                                     Wolffian duct into the cloaca
   Posterior Urethral Valve
            Key Findings on Ultrasound




 Dilated           Dilated bladder   Hydronephrosis
posterior           with possible
 urethra           wall thickening
              Patient 2: Male Fetus on
                Ultrasound (18 wks)




                        Genitalia
                         Legs
PACS, BIDMC
         Patient 2: “Keyhole Sign”: Dilated Bladder
           and Prostatic Urethra on Ultrasound


                               *



                                      *




              Sagittal View

                              Dilated bladder
PACS, BIDMC                   Dilated prostatic urethra
   Patient 2: Bladder Dilatation on Ultrasound (20
                         wks)



                                                                 *

  Sagittal View                             Sagittal View

  Bladder (20                                               Anechoic space
wks) measures                                               demonstrates no flow
4.14 by 2.04 cm                                             on Doppler imaging,
                                                            suggesting a dilated
on sagittal view
                                                            bladder rather than a
                                                            vascular structure

                         Transverse View

                   Normal bladder (18 wks) measures 0.44 cm
PACS, BIDMC                   on transverse view
       Patient 2: Enlarged Hydronephrotic
        Kidneys on Ultrasound (20 wks)
  Right kidney measures 2.80 cm




                                   Left kidney measures 3.42 cm
              *
   Sagittal view

   Bladder
                                                             *
       Normal kidney size: 1
      mm/week x 20 weeks = 20     Sagittal view
           mm or 2 cm
                                                   Spine
                                                  Amniotic
PACS, BIDMC
                                                    Fluid
         Patient 2: Dilated Renal Pelvis
            on Ultrasound (20 wks)
Dilated Pelvis of Left Kidney (0.53 cm)




                         *                Dilated Pelvis of Right Kidney (0.66 cm)




   Transverse view
                                                            *
  At 20 wks: Pelvis <5 mm is normal
  but can be 6-9 mm and normal.
  Here, pelvis>5 mm plus other
  findings suggest obstruction.           Transverse view
PACS, BIDMC
         Patient 2: Amniotic Fluid Measurement on
                        Ultrasound




               Amniotic Fluid estimate: 14.23 mL at 20 weeks
PACS, BIDMC   5-25 mL is the normal range for most of pregnancy
     Patient 3: Visible Ureters and Dilated
        Renal Pelvices on Ultrasound


                                  *

                        *

                                      *




                              Bladder
                               Ureter
Image courtesy of Dr.
Tejas Mehta, BIDMC
                            Renal Pelvis
           Differential Diagnosis for
             Ultrasound Findings
•   Mechanical obstruction
     – PUV
     – Urethral atresia
     – Caudal regression syndrome
     – Megacystis-microcolon-intestinal hypoperistalsis syndrome
     – Prune Belly Syndrome (hypotonic abdominal wall, megacystis,
       ureterectasis, cryptorchidism).
•   Functional obstruction
     – Abnormality in the sphincter, innervation, or musculature of the
       bladder

      PUV is suggested by the keyhole sign, the absence of
    other associated findings, and the severity of obstruction
                 Diagnosis is confirmed postnatally
Accuracy of Ultrasound Evaluation
• In one study:
- 6 fetuses had catheters placed for dilated
  urinary tracts thought to be caused by
  PUV (5) or obstructed megaureter (1)
- 2 were found to have PUV postnatally
        Prognostic Indicators
Patients with PUV often have chronic kidney
disease, VUR, and bladder dysfunction.
Risk factors for poor renal function:
•Diagnosis of PUV before 24 weeks
•Oligohydramnios – when present in 2nd
trimester, mortality is 90-95%
•Serum creatinine >1.0 mg/dL
•Bladder dysfunction
           Renal Outcome
     It is unclear whether PUV and renal
  dysplasia are associated because there is:
- A common developmental injury
- Damage caused by high back pressure
- Recurrent infection causing scarring
                   Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract malformations
• Case of posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
      Clinical Presentation
Neonates: respiratory distress,
dilatated bladder, urinary ascites,
difficulty urinating

Infants: Failure to thrive, urosepsis,
difficulty urinating

Boys: UTIs, incontinence, difficulty
urinating
Postnatal Evaluation: Menu of Tests
Voiding Cystourethrogram (VCUG) is the study of
   choice
• Contrast is injected via a catheter into the bladder
• During micturition, the flow of urine is observed on
   fluoroscopy
Ultrasound can be used to assess hydrouteronephrosis
   and renal parenchyma
If VCUG is not diagnostic, cystourethroscopy can be used
MRI is a developing technology
   -fast sequences or patient sedation required in pediatric
   population
         Patient 4: VCUG Demonstrates Obstruction
              and Unilateral Reflux Postnatally

                                                          Dilated renal pelvis
                                                          Dilated and
                                                          torturous ureter
                             *                            Dilated bladder
                                                          Dilated prostatic
                                                          urethra
                                                          Trabeculations
                                                          Diverticulum
                                     *
                             *
                                         * *
                                 *


                                               1/3-1/2 of patients with PUV
                                               have reflux, which may be
Children’s Hospital Boston                     unilateral or bilateral
  Unilateral or Bilateral Reflux
• In one retrospective study of 200 patients
  with PUV, 27% had unilateral
  vesicoureteral reflux on VCUG and 37%
  had bilateral reflux
• Unilateral reflux may be due to protective
  mechanisms increasing reflux in one kidney
  in order to preserve contralateral kidney
  function (vesicoureteral reflux and
  dysplasia syndrome)
                 Patient 4: Lateral VCUG shows Dilated
                      Bladder and Prostatic Urethra



                                                *
                                      *




                             Dilated bladder with trabeculations
                                       and diverticula

Children’s Hospital Boston
                                  Dilated prostatic urethra
                   Outline
• Normal kidney and urinary tract development
• Normal fetal kidney and urinary tract on
  ultrasound
• Types of kidney and urinary tract malformations
• Case of posterior urethral valve
  - prenatal evaluation
  - postnatal evaluation
• Interventions and long-term outcome
                       Interventions
Prenatal                               Vesicoamniotic shunt
In general, prenatal intervention is
avoided because the benefits have
                                       Open fetal surgery
not been shown to outweigh prenatal
and maternal morbidity
                                       Cystoscopic ablation


Newborn                                Bladder drainage via
                                       feeding tube or catheter
                                       Cystoscopic ablation
                                       Vesicotomy if needed
Older boys                             Cystoscopic ablation
                                            Cystoscopy
                                                            The cystoscope allows
                                                              visualization of the
                                                                 urinary tract

                                                              Surgical instruments
                                                                may be passed
                                                            through the cystoscope

Cystoscopy. Mayo Clinic.
http://www.mayoclinic.com/health/medical/IM00166/undefine
d. Accessed [7/18/10]
       Long-Term Outcome
• Perinatal mortality, caused by pulmonary
  hypoplasia and sepsis, has decreased to
  <10% due to better management
• Long term outcome depends on renal
  parenchymal function
• Renal transplant has been shown to be
  effective in a setting where the bladder
  permits transplant survival
                                               References
Belman A., King L.R., and Kramer S.A. Clinical pediatric urology. 4th edition. London, England: Martin Dunitz Ltd; 2002.
Cystoscopy. Mayo Clinic. http://www.mayoclinic.com/health/medical/IM00166/undefined. Accessed [7/18/10]
DeFoor W., Clark C., Jackson E., Reddy P., Minevich E., and Sheldon C. Risk factors for end stage renal disease in children with posterior urethral
      valves. J Urol. 2008;180(4 Suppl):1705-8; discussion 1708.
Goldstein R.B., and Filly R.A. Sonographic estimation of amniotic fluid volume: subjective assessment versus pocket measurements. J Ultrasound
      Med 1988; 7:363.
Heikkilä J., Rintala, R., and Taskinen S.. Vesicoureteral reflux in conjunction with posterior urethral valves.
      J Urol. 2009;182(4):1555-60.
Holmes, N. Clinical presentation and diagnosis of posterior urethral valves. UpToDate.
      http://www.uptodate.com/online/content/topic.do?topicKey=pediatri/2371&selectedTitle=1%7E150&source=search_result. Accessed [7/14/10].
Holmes, N. Management of posterior urethral valves. UpToDate.
      http://www.uptodate.com/online/content/topic.do?topicKey=pediatri/2087&selectedTitle=1%7E22&source=search_result. Accessed
      [7/14/2010].
Irshad A, Ackerman S., and Ravenel J.G. Horseshoe Kidney. eMedicine. http://emedicine.medscape.com/article/378396-overview. Accessed
      [7/13/10].
Lawrentschuk N., and Frydenberg M. Benign Prostate Disorders. Endotext. http://www.endotext.org/male/male9/male9.html. Accessed [7/18/10]
Massey H.D. Lab I.j Congenital Malformations. Renal Pathology for Medical II Students. http://www.pathology.vcu.edu/education/renal/lab1.j.html
     Accessed [7/15/10].
Moore K.L., and Persaud T.V.N. The Developing Human: Clinically Oriented Embryology. 8th edition. Saunders Elsevier Health Sciences, 2007.
Romero R., Pilu G., Jeanty P., et al. Prenatal diagnosis of Congenital Anomalies. Norwalk: Appleton and Lange, 1998.
Rumack C., Wilson S.R., and Charboneau J.W. Diagnostic Ultrasound. 1st edition. St. Louis, Missouri: Mosby-Year Book, Inc.; 1991.
Rutherford S.E., Phelan J.P., Smith C.V., et al. The four-quadrant assessment of amniotic fluid volume: an adjunct to antepartum fetal heart rate
     testing. Obstet Gynecol 1987; 70:353.
Sarhan O., Zaccaria I., Macher M.A., Muller F, Vuillard E., Delezoide A.L., Sebag G., Oury J.F., Aigrain Y., and El-Ghoneimi A. Long-term outcome
     of prenatally detected posterior urethral valves: single center study of 65 cases managed by primary valve ablation. J Urol. 2008;179(1):307-
     12; discussion 312-3.
Sholder, A.J., Maizels, M., Depp, R., Firlit, C.F., Sabbagha, R., Deddish, R., Reedy, N. Caution in antenatal intervention. J Urol. 1988; 139(5):1026-9
Waters, A. and Rosenblum, N. Evaluation of congenital anomalies of the kidney and urinary tract (CAKUT). UpToDate.
     http://www.uptodate.com/online/content/topic.do?topicKey=pedineph/17792&selectedTitle=1%7E40&source=search_result. Accessed
     [7/11/10].
Waters, A. and Rosenblum, N. Overview of congenital anomalies of the kidney and urinary tract (CAKUT). UpToDate.
     http://www.uptodate.com/online/content/topic.do?topicKey=pedineph/18797&selectedTitle=1%7E150&source=search_result. Accessed
     [7/11/10].
Wiener, J.S., Gaca, A. M., Sekula, J. Posterior Urethral Valve. eMedicine. http://emedicine.medscape.com/article/412226-overview. Accessed
     [7.15.10].
           Acknowledgments
•   Dr. Gillian Lieberman
•   Dr. Mai-Lan Ho
•   Dr. Iva Petovska
•   Dr. Tejas Mehta
•   Maria Levantakis

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:14
posted:10/31/2011
language:English
pages:40