Open surgery appears to be the preferred treatment in patients with nutcracker syndrome: A vascular low frequency disease consortium analysis

Objectives: Nutcracker syndrome (NCS) is an uncommon vascular disease, characterized by anatomical compression of the left renal vein (LRV). Associated symptoms include flank and pelvic pain, as well as hematuria and varicocele. Our objective was to examine the contemporary management of NCS including diagnostic workup for and outcomes of nonoperative and operative treatments. Methods: Patients diagnosed with NCS between 2000 and 2024 were identified through the Vascular Low Frequency Disease Consortium. Demographic, diagnostic, and treatment modalities were reported, including primary and secondary patency, reintervention, and symptom resolution/recurrence. Patient characteristics were reported using descriptive statistics and Kaplan-Meier analysis was used to report outcomes. Results: NCS was diagnosed in 250 patients at 17 institutions. The mean patient age at diagnosis was 37 ± 15 years, 90% were female, and 83% were White. Presenting symptoms and findings included nonpositional flank pain (58%), chronic pelvic pain/dyspareunia (49%), hematuria (48%), nonpositional abdominal pain (47%), and varicocele (3.3%). Diagnostic workup of NCS included computed tomography scan of the abdomen/pelvis (84%), venogram (63%), duplex ultrasound examination (35%), and magnetic resonance imaging (17%). Imaging demonstrated a mean aortosuperior mesenteric artery angle of 27.7°. On duplex ultrasound examination, the mean peak systolic velocity of the LRV was 108.9 ± 99.0 cm/s at the compression point and 21.7 ± 9.5 cm/s at the hilum, with a peak systolic velocity ratio of 4.98, whereas venography demonstrated a mean renocaval pressure gradient of 3.92 ± 2.40 mm Hg. Nonoperative treatment with oral analgesics (29%), nutritional counseling/feeding regimen (16%), or simple expectant management (55%) was used in 116 patients and successful in 90 patients (78%) with a mean follow-up of 328 days. Indications for nonoperative management included mild symptoms (64%), young age (10%), and patient preference (8.4%). Of the 26 patients (22%) who failed nonoperative treatment, 20 were subsequently managed with surgery. In the 134 patients who underwent surgery, either as initial treatment or after nonoperative failure, 60 (44%) had a LRV transposition, 43 (31%) underwent a gonadal/ovarian vein transposition, 18 (12%) underwent renal autotransplantation, and 19 (13%) underwent endovascular therapy. The overall 3-year primary patency and secondary patency were 65% (95% confidence interval [CI], 51-76) and 96% (95% CI, 88-99), respectively. The 3-year freedom from reintervention and symptom recurrence were 67% (95% CI, 53-78) and 60% (95% CI, 48-70), respectively. Patients who underwent endovascular intervention had inferior primary patency and freedom from symptom recurrence: 35% (95% CI, 1.22-78) and 46% (95% CI, 7.99-79), respectively. Conclusions: Approximately 20% of patients with NCS initially managed nonoperatively progressed to operative intervention. Surgery was associated with excellent secondary patency, but a substantial number of patients required reinterventions and 40% developed symptom recurrence by 3 years, highlighting the need for judicious patient selection for surgery through preoperative counseling and shared decision-making. Endovascular therapy was associated with significantly worse results for all outcomes and, therefore, is not appropriate as initial treatment.