My personal view is that is depends on your experience, training, and frequency of performing these cases. If you do not do it regularly and are not familiar handling blood vessels, you should probably have an access surgeon. If, however, you perform this regularly and are familiar with structures in this area, you may be more familiar with the approach than a vascular surgeon who does not normally perform a retro-peritoneal approach.
For these reasons, I perform anterior approaches myself but I ensure there is a vascular surgeon available in the hospital before I start the case and that I have notified them that the case is going ahead. If it is a revision anterior procedure or a primary anterior procedure for infected posterior implants or interbody cage, the vessels can be very stuck down and I will have a vascular surgeon assisting from the start of the case.
It would be interesting to hear from surgeons working in units where vascular surgery is not on site and if they do anything differently.