Robotic assisted extravascular stent placement for nutcracker phenomenon of the left renal vein: a case series.

Nutcracker phenomenon of the left renal vein is a rare anatomic anomaly that can present with chronic flank/pelvic pain, pelvic congestion, and hematuria. Conventional treatment options (superior mesenteric artery transposition, endovascular stent placement, auto-transplantation) involve substantial risk, morbidity, or the need for chronic anti-coagulation. We now report our institution's robotic experience with extravascular left renal vein stent placement. A retrospective, single surgeon series from December 2016 to May 2019 was reviewed. After positioning and port placement (three robotic ports, one assistant), the left renal vein was exposed and dissected free circumferentially down to the inferior vena cava insertion. The distance between the renal vein ostium and adrenal vein was measured and a 1 cm-diameter ringed polytetrafluoroethylene vascular stent of this length placed. The stent edges were secured to itself with 3-0 polyglactin sutures. Demographics, surgical, and functional outcomes were collected. Six patients with mean age of 45 ± 6 years and body mass index of 20.3 ± 3.3 g underwent the procedure. Mean operative time was 143 ± 20 min. Estimated blood loss was minimal. Mean graft length utilized was 2.25 ± 0.3 cm. Median day of discharge was 1.5 days (range 1-3). No high-grade complications occurred. All patients received immediate pain relief and 50% also saw other symptomatic improvements. Robotic assisted extravascular left renal vein stent placement appears safe and effective in a small cohort with short follow-up. Further long-term follow-up for pain relief and graft-related complications are needed.