1. Medical Student Case Study: Horseshoe Kidney in an Infant
August 2013
Emma Simpson
Konrad Bienia MD & Eric Sutherland MD

2. The Patient
5 mo old boy
Ex-preemie (35 weeks)
Previous admission for community-acquired viral infx
O/p visit for assessment of HSK seen on prenatal US
Fever (Tmax 101’)
FTT (Zeroeth percentile in all parameters.)
Stage 1 Chronic Kidney Disease
Abnormal urinalysis

3. Because who doesn’t love embryology?
Renal Embryology
Because who doesn’t love embryology?
During retroperitoneal ascent: rotate almost 90 degrees so that the hila are eventually directed anteromedially.
4 weeks
9 weeks

4. Fusion Abnormalities Crossed, fused ectopia Horseshoe Kidney
The estimated incidence is around 1 out of 1,000 births
Male: Female; 2:1
Horseshoe Kidney
0.25% of the general population
More common in men.

5. Horseshoe Kidney Pathology

6. Clinical History & Physical Exam
MAINLY asymptomatic – autopsy finding
UTI and fever in neonates
Abdominal surgery: BEWARE
Mostly of interest to radiology nerds.
Can have sequelae related
to poor drainage…

7. Chronic Kidney Disease in a newborn
DDx
Depends on symptoms.
Chronic Kidney Disease in a newborn
Premature birth/trisomies/non-aneuploidic anomalies
Acute Kidney Injury becoming chronic
Congenital
Hypoxic ischemic injury
Toxic injury
Prenatal: Renal dysplasia with or without obstructive uropathy and in genetic diseases such as autosomal recessive polycystic kidney disease.
Hypoxic ischemic injury: Vasculature -
Toxic: NSAIDS (indomethacin for PDA closure); aminoglycosides

8. What does a diagnosis mean?
Clinical Sx
Nausea, abdominal discomfort, kidney stones and urinary tract infections at greater frequency than those without renal fusion.
Risks
Trauma
Renal calculi
Transitional cell carcinoma of renal pelvis/Wilms tumor
Chronic Kidney Disease
CKD due to reflux nephropathy

9. Imaging Modalities for HSK
Ultrasound
Fluoroscopy - IVU
CT and MRI
ACR: Do not irradiate babies
PLUS: Very specific area to be imaged, and can be easily visualized. Babies are small. Cheap and fast.

10. Normal US Right Kidney

11. Normal US Kidney

12. Left Longitudinal Retroperitoneal US: HSK
MRN:

13. Right Longitudinal Retroperitoneal US: HSK
MRN:

14. Transverse Retroperitoneal US
Diagnosis made because of isthmus
MRN:

15. Symptomatic management In this pt:
Horseshoe Kidney
No tx for HSK
Adequate hydration
Symptomatic management
In this pt:
Lost to follow-up
Mom moved out of state
Social Services concerns

16. Thank You

17. References
Gupta, M., A. K. Pandey, and N. Goyal. "Horseshoe Kidney--a Case Report." Nepal Med Coll J 9.1 (2007): Print.
Carmody, J. B., and J. R. Charlton. "Short-Term Gestation, Long-Term Risk: Prematurity and Chronic Kidney Disease." Pediatrics (2013): Print.