Venous Anomalies Complicating Anterior Lumbar Interbody Fusion Exposures.

The effects of anomalous vasculature impeding optimal exposure to an anterior lumbar interbody fusion approach are limited in literature. We present five individual, unique cases of vascular anomalies in patients undergoing two-stage anterior-posterior lumbar interbody fusion. Cases 1, 2, 4, and 5 have yet to be described in literature in context of anterior lumbar interbody fusions. Case 3 presents anomalous vasculature that has only been described in two other case reports. Case 1 presents the right internal iliac vein originating from the left common iliac vein which was transected for L4-L5 vertebral disc exposure. Case 2 presents the left internal iliac vein originating from the right common iliac vein which required an oblique approach. Case 3 presents a duplicated inferior vena cava that was taken into account but did not interfere with the anterior retroperitoneal approach. Case 4 presents large osteophytes adhering to the left common iliac vein which limited safe dissection and mobilization. Case 5 presents the left internal iliac vein with a high takeoff spanning across the L5-S1 vertebral disc space and requiring transection. This case series highlights the need for preoperative imaging and a working detailed knowledge of anatomy to avoid damaging vasculature that can potentially lead to fatal consequences. The information given in this case series should inform both spine and vascular surgeons on proper preoperative planning. To maximize operative efficiency and safety, spine surgeons and vascular surgeons should collaborate to minimize surgical complications.