Retroaortic Left Renal Vein in Para-Aortic Lymphadenectomy: A Case Report

A retroaortic left renal vein (RLRV) is an anatomical variant in which the left renal vein courses posterior to the abdominal aorta before draining into the inferior vena cava.This variant may be important during paraaortic lymphadenectomy because unexpected venous anatomy can increase the risk of vascular injury.We describe a 44-year-old female undergoing surgical staging for right ovarian mucinous carcinoma whose RLRV was identified on preoperative contrast-enhanced computed tomography (CT).During para-aortic lymphadenectomy, careful blunt dissection was advanced cranially along the left lateral border of the aorta until the inferior border of the RLRV was identified.The left ovarian vein drained into the left renal vein.The procedure was completed without vascular injury; estimated blood loss was 509 mL for the entire operation.Histopathology showed International Federation of Gynecology and Obstetrics (FIGO) stage IA mucinous ovarian carcinoma, with no metastases in 37 pelvic or 11 para-aortic lymph nodes and negative peritoneal washing cytology.No adjuvant chemotherapy was administered, and the patient remained recurrence-free at 15 months.Postoperative three-dimensional CT reconstruction yielded a 180° rotational sequence of 36 images.The reconstruction was not used for surgical planning.This case emphasizes the importance of preoperative review of renal venous anatomy and careful intraoperative identification of vascular landmarks.