From the Guidelines
Horseshoe kidney is a congenital anomaly where the two kidneys are fused together at their lower ends, forming a U-shaped structure, and it is essential to recognize this condition due to its potential complications, such as urinary tract infections and kidney stones, as reported in studies like Jothilakshmi et al 1 and Huang et al 1.
Definition and Prevalence
Horseshoe kidney is a rare congenital birth defect, occurring in about 1 in 500 people, with a higher prevalence in males than females.
- It is characterized by the fusion of the two kidneys at their lower ends during fetal development, resulting in a U-shaped or horseshoe-like structure.
- The fused portion, called the isthmus, typically connects the lower poles of both kidneys and is located in front of the spine and major blood vessels.
Clinical Implications
While many people with horseshoe kidney have no symptoms and the condition is discovered incidentally during imaging for other reasons, it can be associated with an increased risk of:
- Urinary tract infections
- Kidney stones
- Ureteropelvic junction obstruction due to abnormal drainage
- The fusion also makes the kidneys more susceptible to trauma because they cannot move as freely as separate kidneys.
Diagnosis and Treatment
Treatment is only necessary if complications arise, and may include surgery to correct blockages or remove stones.
- The condition itself doesn't typically affect kidney function, and most people with horseshoe kidney lead normal lives without any kidney-related problems, as supported by the findings of Jahnukainen et al 1 and Montini et al 1.
- It is crucial to monitor and manage any potential complications to prevent long-term damage to the kidneys and ensure optimal quality of life.
From the Research
Definition and Prevalence of Horseshoe Kidney
- Horseshoe kidney is the most common renal fusion anomaly, occurring in approximately 1 in 500 individuals worldwide 2.
- It is characterized by abnormalities in kidney position, rotation, and vascular supply.
Anatomical Characteristics
- Horseshoe kidney is defined by three anatomic anomalies: ectopia, malrotation, and vascular changes 3.
- The arterial supply patterns of horseshoe kidney can vary, with the majority being supplied by renal arteries derived from the abdominal aorta below the isthmus or by vessels originating from the common iliac arteries 3.
Complications and Associated Risks
- Horseshoe kidney can lead to urological complications, primarily due to ureteric obstruction and impaired urinary drainage 2.
- Patients with horseshoe kidney are at increased risk for neoplasms, infections, ureteropelvic obstruction secondary to lithiasis or vascular compression, and direct injury from trauma 4.
- The risk of end-stage renal disease (ESRD) is higher in patients with horseshoe kidney compared to the general population 5.
Management and Treatment
- Ureteropelvic junction obstruction in horseshoe kidney can be managed by percutaneous endopyelotomy or laparoscopic pyeloplasty with good results 6.
- Small stones associated with horseshoe kidney are best managed by shock wave lithotripsy, while larger stones may require percutaneous management 6.
- Laparoscopic nephrectomy is a safe and feasible option for benign and malignant horseshoe kidney diseases 6.