Technique-stratified reintervention outcomes after surgical reconstruction for nutcracker syndrome: a single-center retrospective study

Abstract

Nutcracker syndrome (NCS) is an uncommon venous compression disorder resulting from extrinsic compression of the left renal vein (LRV), either between the superior mesenteric artery (SMA) and the aorta (anterior NCS) or between the aorta and the vertebral body (posterior NCS). Owing to the wide spectrum of clinical manifestations, diagnosis is often delayed. The aim of this study was to evaluate the surgical and follow-up outcomes of patients who underwent operative treatment for NCS at our institution, with particular attention to outcomes stratified by surgical technique. Eighteen consecutive patients (5 men [27.8%] and 13 women [72.2%]) with NCS who underwent a transabdominal surgical approach between June 2022 and April 2025 were included. Demographic data, preoperative clinical status, intraoperative findings, and postoperative outcomes were retrospectively analyzed. McNemar's exact test was used to compare paired preoperative and postoperative findings, and Fisher's exact test (with Freeman–Halton extension) was used to compare reintervention rates among surgical techniques. Mean age was 20.5 ± 7.79 years (range, 11–33); mean body weight was 51.1 ± 7.87 kg (range, 35–64). Flank pain (15 patients, 83.3%) was the most frequent symptom and microscopic hematuria (10 patients, 55.6%) the most common urinary finding. SMA syndrome was concomitant in 5 patients (27.8%). Surgical techniques were graft interposition (9 patients, 50.0%), LRV transposition with end-to-side anastomosis (5 patients, 27.8%), and gonadal/ovarian vein transposition (4 patients, 22.2%). No postoperative renal dysfunction or renal vein thrombosis occurred. During follow-up (mean, 13.5 ± 5.77 months), 7 patients (38.9%) required transcatheter reintervention; rates differed across techniques (LRV transposition, 80.0%; graft interposition, 33.3%; gonadal/ovarian vein transposition, 0%; Freeman–Halton exact p = 0.072). Flank pain ( p < 0.001), hematuria ( p = 0.001), and proteinuria ( p = 0.016) decreased significantly versus preoperative status. Surgical reconstruction was associated with significant clinical improvement in patients with NCS, although accompanied by a substantial reintervention rate that underscores the need for close postoperative surveillance. A trend toward higher reintervention rates after LRV transposition compared with graft interposition or gonadal/ovarian vein transposition was observed but did not reach statistical significance in this small cohort. Close follow-up is essential, as endovascular reintervention may be required for residual or recurrent stenosis.