horseshoe kidney
A congenital fusion anomaly where the lower poles of both kidneys are connected by a band of renal tissue or fibrous isthmus.
Full Definition
Horseshoe kidney is the most common renal fusion anomaly, occurring in approximately 1 in 400-500 births, with a 2:1 male predominance. The condition results from fusion of the lower renal poles during embryonic development, creating a horseshoe-shaped structure connected by an isthmus that crosses the midline anterior to the aorta and inferior vena cava. The fusion typically prevents normal renal ascent, leaving the kidneys in a lower position. While many individuals remain asymptomatic, complications can include increased risk of ureteropelvic junction obstruction, nephrolithiasis, and urinary tract infections.
Usage
Usage note: Always hyphenated when used as a compound adjective; the descriptive name helps distinguish it from other renal anomalies.
In Context
- "The CT scan revealed a horseshoe kidney with evidence of left-sided hydronephrosis." — Diagnostic imaging report
- "Patients with horseshoe kidney require careful surgical planning due to aberrant vascular anatomy." — Surgical consultation note