Renal Fusion Anomalies: A Review of Surgical Anatomy

Congenital renal fusion anomalies, characterized by either partial or complete fusion of the two kidneys, are represented by horseshoe kidney, crossed renal ectopia with fusion and fused pelvic cake kidney. Though these anomalies may remain asymptomatic, in certain cases they may be associated with pathological conditions like nephrolithiasis, hydronephrosis, recurrent urinary tract infections, vesicoureteral reflux and renal neoplasms. Concomitant congenital anomalies involving other organ systems observed with some renal fusion anomalies make them important clinical entities. Thorough knowledge of these renal fusion anomalies, associated renovascular abnormalities, pathologies and anomalies of other organ systems are most essential for appropriate patient management by urologists, surgeons, vascular surgeons and radiologists alike. This review focuses on the surgical anatomy of various renal fusion anomalies, their incidence, anatomical, radiological and pathological features and associated anomalies in the light of available literature.