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

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

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 http://academic.amc.edu/martino/grossanatomy/site/Medical/CASES/R&R/pop%20ups/hydronephrosis%20anspop_up4.htm

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.

Horseshoe Kidney Pathology

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… http://elettrogenica.tumblr.com/page/2

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 http://en.wikipedia.org/wiki/Autosomal_dominant_polycystic_kidney

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

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. https://www.akronchildrens.org/cms/procedures_tests/Ultrasound_infant_hip/

Normal US Right Kidney http://www.ultrasoundpaedia.com/normal-kidney/

Normal US Kidney http://www.ultrasoundpaedia.com/normal-kidney/

Left Longitudinal Retroperitoneal US: HSK MRN: 6566544

Right Longitudinal Retroperitoneal US: HSK MRN: 6566544

Transverse Retroperitoneal US Diagnosis made because of isthmus MRN: 6566544

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

Thank You

References Gupta, M., A. K. Pandey, and N. Goyal. "Horseshoe Kidney--a Case Report." Nepal Med Coll J 9.1 (2007): 63-6. Print. http://radiopaedia.org/ Carmody, J. B., and J. R. Charlton. "Short-Term Gestation, Long-Term Risk: Prematurity and Chronic Kidney Disease." Pediatrics 131.6 (2013): 1168-79. Print. http://en.wikipedia.org/wiki/Horseshoe_kidney http://www.chop.edu/img/urology/horseshoe-kidney.html http://renalfellow.blogspot.com/2008/09/horseshoe-kidney-versus-crossed-fused.html