From the Guidelines
Horseshoe kidney is a congenital abnormality that requires careful management to prevent complications, and clinicians may obtain additional contrast imaging if further definition of the collecting system and the ureteral anatomy is needed, as recommended by the American Urological Association/Endourological Society guideline 1. This condition affects approximately 1 in 500 people and is more common in males than females. Most people with horseshoe kidneys remain asymptomatic throughout their lives and require no treatment. However, the abnormal positioning can lead to complications including urinary tract infections, kidney stones, and ureteropelvic junction obstruction due to impaired drainage. Some key points to consider in the management of horseshoe kidney include:
- The use of additional contrast imaging to define the collecting system and ureteral anatomy, as needed 1.
- The potential for complications such as urinary tract infections, kidney stones, and ureteropelvic junction obstruction 1.
- The importance of regular monitoring with ultrasound or CT scans to detect complications early in symptomatic patients. If symptoms develop, treatment focuses on addressing the specific complications rather than the horseshoe kidney itself. For urinary tract infections, appropriate antibiotics are prescribed based on culture results. Kidney stones may require extracorporeal shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy. Ureteropelvic junction obstruction might necessitate pyeloplasty to improve drainage. The fusion occurs because as the kidneys ascend from the pelvis during development, they get trapped by the inferior mesenteric artery, preventing complete separation and resulting in the characteristic horseshoe shape. Studies have shown that horseshoe kidney can be associated with other congenital anomalies, such as duplex kidney, crossed renal ectopia, and polycystic kidney 1. In patients with horseshoe kidney, it is essential to consider the potential for complications and to monitor them regularly to detect any issues early on 1.
From the Research
Definition and Prevalence of Horseshoe Kidney
- Horseshoe kidney (HSK) is a congenital disorder that affects about 0.25% of the global population 2.
- It is the most common renal fusion congenital anomaly.
Clinical Findings and Complications
- HSK may present with clinical findings, including urinary tract infections (UTI), stone formation, and obstruction 2.
- Nephrolithiasis is observed in 20% of patients with HSK, and is a frequent indication for surgery 2.
- The presence of anatomic obstruction may necessitate open surgery for urolithiasis in patients with HSK 3.
- Patients with HSK are at risk of end-stage renal disease (ESRD), which may be attributable to the high prevalence of complications such as obstruction, kidney stones, urinary tract infection, and urogenital cancer 4.
Treatment Options
- Laparoscopic surgery is a promising alternative for stone treatment in HSK, with advances in laparoscopic instrumentation and techniques making it an effective and safe approach 2.
- Percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) are also treatment options for HSK, with ESWL achieving a 100% disintegration rate and a 76% stone-free rate in patients with normal drainage and a small to moderate stone burden 3.
- Endoscopic management, including PNL, ureteroscopy (URS), and ESWL, can be used to treat urolithiasis in HSK, with stone-free rates of 81.1% for PNL, 84% for URS, and 50% for ESWL 5.
- A tailored approach based on stone size is highly recommended, with ESWL accompanied by ureteric stenting being a promising strategy for the management of stones associated with HSK in selected patients requiring intervention 6.