SS10 - Open Surgery is Superior to Endovascular Therapy in Patients with Nutcracker Syndrome

Objectives: Nutcracker syndrome(NCS) is an uncommon vascular disease, characterized by anatomic 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 work-up and outcomes of non-operative and operative treatment.

Methods: Patients diagnosed with NCS between 2000-2024 were identified through the Vascular Low Frequency Disease Consortium(VLFDC). Demographic, diagnostic, and treatment modalities were reported, including primary and secondary patency, reintervention, and symptom resolution/recurrence. Operative treatment was defined as either open surgery or endovascular therapy. Patient characteristics were reported using descriptive statistics and Kaplan-Meier analysis.

Results: NCS was diagnosed in 240 patients at 17 institutions. Mean age was 37±15 years, 90% were female, and 83% were White. Presenting symptoms included non-positional flank pain(58%), chronic pelvic pain/dyspareunia(49%), hematuria(48%), non-positional abdominal pain(47%), and varicocele(3.3%). Diagnostic work-up of NCS included CT imaging of the abdomen/pelvis(84%), venogram(63%), duplex ultrasound(35%), and MRI(17%). On duplex ultrasound mean PSV of the LRV was 108.9±99.0 cm/s at the compression point and 21.7±9.5 cm/s at the hilum, while venography demonstrated a mean reno-caval pressure gradient of 3.92±2.40 mmHg.

Non-operative treatment with oral analgesics(29%), nutritional counseling/feeding regimen(16%), or simple expectant management(55%) was used in 107 patients and successful in 85(79%) (mean follow-up 306±562 days). Indications for non-operative treatment included mild symptoms(64%), young age(10%), and patient preference(8.4%). Of the 22(21%) patients that failed non-operative treatment, 17(16%) were subsequently managed with surgery.

In the 146 patients who underwent operative treatment, either as initial treatment or after non-operative failure, 60(41%) had a LRV transposition, 43(29%) underwent a gonadal/ovarian vein transposition, 18(12%) underwent renal auto-transplantation, and 19(13%) underwent endovascular therapy. The overall three-year primary patency and secondary patency were 65%(95%CI, 51-76) and 96%(95%CI, 88-99), respectively. Three-year freedom from reintervention and symptom recurrence were 67%(95%CI, 53-78) and 60%(95%CI, 48-70), respectively(Figures 1-2). Patients who underwent endovascular therapy had inferior three-year primary patency and freedom from symptom recurrence compared to patients who underwent open surgery: 35%(95%CI, 1.22-78) and 46%(95%CI, 7.99-79), compared to 67%(95%CI, 54-78) and 61%(95%CI, 49-72), respectively.

Conclusions: Approximately 20% of patients with NCS initially managed non-operatively 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 three years, highlighting the need for judicious patient selection for surgery. Endovascular therapy was associated with significantly poorer results for all outcomes and therefore is not appropriate as initial treatment.