18 years of experience with pediatric nutcracker syndrome: The importance of conservative approach

Extended Summary INTRODUCTION Nutcracker Syndrome (NS) defines an entity generated by the compression of the left renal vein resulting in venous hypertension, which transmitted in a retrograde direction may cause hematuria, proteinuria and varicocele. Literature concerning exclusively pediatric patients is very rare. We report our experience with pediatric NS in the last 18 years. MATERIAL AND METHODS Retrospective review of the patients followed in our center with diagnosis of NS based on clinical and imaging tests (ultrasound, CT/MRI, phlebography). The primary outcome was the success of conservative approach in our patients. RESULTS 21 patients were diagnosed with NS and followed up for a mean period of 52.3 months (37.1-67.5). Mean age at diagnosis was 11.7 years (9.9-13.4). The most frequent symptom of presentation was hematuria in 16 patients (76.2%), being macroscopic in 75% and in 42.9% related to physical exercise. Other symptoms were left varicocele in 7 patients (33%) and proteinuria in 6 patients (28.6%). Mild to moderate cases received conservative treatment (change of physical activity, postural hygiene), which achieved resolution of symptoms in 16 patients (76.2%). 5 cases (23.8%) finally needed a more aggressive approach. 2 (9.5%) of them required endovascular procedures (intravascular stent in the renal vein in 1 case, and embolization of the spermatic vein in 1 case), in 1 (4.8%) of the patients, transposition of the left renal vein and kidney autotransplantation were performed, and 2 (9.5%) of the patients with mild cases required surgical correction of the varicocele. CONCLUSIONS Hematuria, usually macroscopic and related to physical exercise, is the most frequent symptom in pediatric patients with NS. We advocate studying the aortomesenteric junction with abdominal ultrasound in patients with varicocele or with intermittent macroscopic hematuria. Diagnosis is based on non-invasive tests; phlebography should be reserved for severe cases that require an interventionist attitude. A long period of conservative treatment is the first approach for pediatric patients with NS.