Robotic left renal vein transposition for nutcracker syndrome: side-clamp to tailored reconstruction

Our objective was to evaluate the safety and efficacy of staged, anatomy-tailored robot-assisted left renal vein (LRV) transposition procedures for the treatment of nutcracker syndrome (NCS).

This retrospective single-centre study (2019-2025) included 88 patients stratified by technique: conventional (n = 27), robotic side-clamp two-step (n = 21), LRV-proximal left gonadal vein (LGV) transposition (n = 20), and LRV-distal LGV transposition (n = 20). The primary outcome was the renocaval pressure gradient (RPG), with secondary outcomes including operative metrics, symptom resolution, and complications. Median follow-up was 12 months.

Robot-assisted LRV-distal LGV transposition groups demonstrated superior perioperative outcomes to conventional surgery: operative time (median 200 vs 344 min; P < 0.001), blood loss (36.5 vs 66.0 mL; P < 0.001), and hospital stay (4.5 vs 8.0 days; P < 0.001). Postoperative RPG was ≤3 mmHg in all patients. The LRV-proximal LGV transposition yielded the greatest RPG reduction (Δ2.8 mmHg) and lowest postoperative RPG (1.5 mmHg). Complete resolution of varicocele and pelvic/scrotal pain was achieved in all eligible patients undergoing the LRV-distal LGV transposition. Pain scores were low across all groups (mean pain score: 1.7).

The staged technical evolution in robotic LRV transposition, from the side clamp two-step technique to anatomy-tailored LRV-LGV transposition, demonstrated favourable renocaval pressure gradient normalization, symptom relief, and perioperative outcomes. Based on our single-centre experience, we propose a preliminary anatomy-tailored treatment algorithm: the side clamp two-step technique for uncomplicated cases, LRV-proximal LGV transposition for proximal LGV dilation (≥5 mm), and LRV-distal LGV transposition for patients with varicocele or pelvic congestion. This framework serves as an institutional reference that warrants further multicentre validation.