Major retroperitoneal venous anomalies: surgical considerations.

Nineteen major anomalies of the vena cava or its branches were encountered in patients requiring abdominal vascular surgery and related procedures at Barnes Hospital during the past 5 years. The classification of these anomalies, their embryologic development, associated variants, and surgical considerations are discussed. Careful review of preoperative computed tomographic scans and familiarity with these anatomic variants may allow the surgeon effectively to avoid potentially disastrous intraoperative consequences.