From the Research
Patients with a congenital solitary kidney should undergo regular monitoring throughout their lifetime to detect and manage potential complications, with a recommended follow-up tailored to individual risk stratification, as outlined in the most recent consensus recommendations 1. The monitoring should include annual check-ups with blood pressure measurement, urinalysis for protein detection, and renal function tests (serum creatinine, estimated glomerular filtration rate) 2, 3, 1.
- Ultrasound evaluations should be performed every 1-2 years to assess kidney growth, structure, and to detect any abnormalities such as hydronephrosis or stones.
- For children, monitoring should include tracking growth and development.
- If hypertension develops, ACE inhibitors or ARBs (such as enalapril 5-40 mg daily or losartan 25-100 mg daily) are typically first-line treatments as they provide renoprotective effects beyond blood pressure control 2, 3.
- Significant proteinuria (>300 mg/day) should prompt consideration of these medications even in normotensive patients.
- Patients should maintain adequate hydration, follow a balanced diet moderate in protein (0.8-1.0 g/kg/day), and limit sodium intake to <2.3 g/day.
- Regular exercise should be encouraged, though contact sports carrying risk of kidney injury should be approached cautiously. This monitoring regimen is important because a solitary kidney faces increased hemodynamic stress and hyperfiltration, which can lead to progressive glomerular damage, hypertension, proteinuria, and eventual decline in kidney function if not properly managed 4, 5. Key factors to consider in the management of congenital solitary kidney include the presence of congenital anomalies of the kidney and urinary tract (CAKUT), which increases the risk of chronic kidney disease and progression to chronic renal failure 2, 1, 4. The role of voiding cystourethrography and antibiotic prophylaxis remains controversial, and is complicated by the exclusion of children with a congenital solitary kidney from studies 2. Annual ambulatory blood pressure measurement should be considered due to the prevalence of masked hypertension 2. Lifelong follow-up is necessary, with the frequency and modality of follow-up adapted to individual risk for chronic kidney disease 3, 1. Early detection of renal injury and timely nephroprotective measures are critical to improve the prognosis of patients with congenital solitary kidney 4.