Outcomes of Left Renal Vein Stenting in Patients with Nutcracker Syndrome

Abstract

Nutcracker syndrome (NCS) is a rare condition that can present with hematuria, flank pain, pelvic varicosities, or chronic pelvic congestion related to left renal vein (LRV) compression. Open surgery, specifically LRV transposition, has been the mainstay of treatment, but during the past few years, LRV stenting has emerged as a valid alternative without sufficient evidence to support it. This study aimed to assess outcomes of renal vein stenting in the treatment of NCS. A retrospective chart review of patients with NCS who underwent LRV stenting between 2010 and 2018 was performed. End points were perioperative adverse outcomes, symptom relief, and stent patency. Symptom resolution was classified as complete, partial, and none on the basis of the interpretation of medical records on clinical follow-up. Standard descriptive statistics and survival analysis were used. Seventeen patients (16 female; mean age, 35.8 ± 14.6 years; mean body mass index, 21.3 ± 4.1 kg/m2) diagnosed with NCS and treated with LRV stenting were identified. Five of these had a prior LRV transposition that had failed within a mean of 7.0 ± 4.9 months. Ten patients had coexisting pelvic congestion syndrome treated with gonadal vein embolization. The most frequent sign and symptom were hematuria (9/17 patients) and flank pain (14/17 patients), respectively. All patients received self-expanding stents (mean diameter, 12.7 ± 1.6 mm), the smaller ones typically placed in the previously transposed LRVs. No perioperative complications occurred. Eight patients were discharged on the same day; the remaining stayed longer for pain control (mean hospital stay, 1.0 ± 1.3 days). At an average follow-up of 33 ± 25 months, 13 (76.5%) patients had symptom relief (9 complete, 4 partial). Three of the four patients whose symptoms persisted had previous LRV transposition surgery. Five of nine patients who presented with hematuria had it resolved. Three patients underwent a reintervention. Two of these had successful balloon venoplasty for restenosis. The third patient had persistent debilitating pain despite a patent stent and eventually underwent renal auto transplantation with no symptom relief. Two-year primary and primary assisted patencies were 81.8% and 90%, respectively. No stent migration occurred. Endovascular treatment with renal vein stenting is safe and effective, providing good midterm patency rates and symptom relief. Minimally invasive approaches may have a potential role in the treatment of NCS. Larger series and longer follow-up are needed to better assess its comparative performance against LRV transposition.