Objective: To identify anomalies of major retroperitoneal vascular structure (AMRVS) during oncological retroperitoneal surgery and to investigate the effects of these anomalies in surgical procedures.

Materials and Methods: Two hundred twenty-nine patients who underwent systematic para-aortic and bilateral pelvic lymph node dissection up to the renal vein between September 2006 and December 2008 were included. Normal architecture and structural anomalies of inferior vena cava, abdominal aorta, renal arteries and veins, and common iliac artery and vein were studied.

Results: The mean age of the patients was 54.2 years. Anomalies of major retroperitoneal vascular structure were present in 39 patients (17%). Anomalies of renal vessels were identified in 31 patients. Supernumerary renal arteries and veins observed in 11 patients (17%) were the most common renal vessel anomaly. Great vessel injury was present in 19 patients (8.3%). Vascular complication rate was 20.5% in patients with AMRVS. However, in 4 of 8 patients with vascular complication and AMRVS, the complication was not related with anomalous vascular structures. None of the complications was serious and were corrected surgically. There was no difference between patients with AMRVS and those without AMRVS regarding age, body mass index, the extent of upper abdominal dissemination of malignancy and presence of comorbidity for intraoperative bleeding. There was no difference in intraoperative hemorrhage and amount of transfused red blood cell units between the groups.

Conclusion: Great vessel anomalies, discovered in 1 of 6 patients, were together with increased risk of vascular complications. The probability of presence of vascular anomalies should be taken into account during lymph node dissection.