Single-center initial experience with minimally invasive extravascular stent placement for nutcracker syndrome in adolescent patients.

Nutcracker Syndrome (NCS) is characterized by impeded blood flow from the Left Renal Vein (LRV) into the inferior vena cava due to an abnormally narrow angle between the abdominal aorta and superior mesenteric artery. This syndrome is usually associated with hematuria, abdominal pain and orthostatic proteinuria. We described three patients diagnosed with NCS (mean age 16.3 years). The aortomesenteric angle, LRV diameter ratio and peak velocity ratio were assessed through doppler ultrasonography and CT angiography. A kidney model was printed out for surgical planning. An extravascular stent was designed based on the LRV's structure using computer software and printed in three dimensions with a precision setting of 20μm. Patients underwent laparoscopic placement of the extravascular stent. The mean duration of surgery was 180 minutes. There were no intraoperative complications. CT examinations revealed that pre- and postoperative AMA ranged from 18.7°±4.3° to 55.0°±4.4, respectively. No side effects were observed in the follow-up period (range 12-24 months). At present, treatment guidelines for NCS are unclear, and the different therapeutic principles need to be applied in a patient-specific manner. Our results confirm previous reports in literature concerning the efficacy and safety of ES in pediatric patients.