Objective    To research regional anatomy of lumbar sympathetic trunk and provide anatomic information for video-assisted laparoscopic lumbar sympathectomy (VALLS).     Methods    Lumbar sympathetic trunk and its neighboring anatomic relation in 128 sides of adult cadavers and 21 clinic VALLS were retrospectively reviewed.     Results    ① The location

shape and number of the sympathetic ganglia were quite variable. There was 1 to 6 in number unilaterally. ② Lumbar sympathetic trunks of 12 sides in 128 sides were found dividing into 2-3 branches at the distal part. ③ Lumbar arteries were all located under the lumbar sympathetic trunk and the lumbar veins consisting 68.42% situated superficially to the trunk. ④ Genitofemoral nerve pierced the psoas muscle at the level of 2nd to 4th vertebrate or its intervertebral disc. It was only (0.81±0.48) cm away from the medial rim of the psoas muscle. ⑤ Distance between ureter-iliac vessel junction and the lateral rim of the psoas muscle was (3.36±0.59) cm at left side and (3.41±0.59) cm at right side. The operation time was 2-3.5 hours and the intraoperative blood loss was 50-80 ml. There were no severe complications and the effects were satisfying.      Conclusion    Because of great variants and complex neighboring anatomic relation of lumbar sympathic nerve

the critical factor of successful microinvasive VALLS is to grasp the laparoscopic operation skill and anatomy of retroperitoneal space (especially the regional anatomy of lumbar sympathetic trunk) and carefully operating.