I've noticed a lot of Plastic Surgeons and Dermatologists are adding some variation of phalloplasty to their menu of services, especially in light of the improvements made in the field. It's kind of popping up all over the place, and not surprisingly, there are less than stellar results I've seen from lesser experienced practitioners. That isn't to say this Doctor can't provide a satisfactory result, but we'll have to hope some of his patients chime in.
Can't say I've heard of him (ever) but it appears from his website that he uses hyaluronic acid for girth enhancement.
The most experienced Practitioners on the West Coast are Dr. Casavantes (Tijuana, Mexico, minutes from San Diego) and Dr. Solomon (who's based out of Philadelphia but has a Beverly Hills location). They perform non-surgical and surgical procedures respectively.
Voluma is a modified Hyaluronic Acid (temporary) Dermal Filler product. Whenever you see "HA" on these forums, Voluma is one of a few brands of said-HA.
Relatively speaking it's a safe means to enlargement but neither permanent and probably not recommended in high large volumes in that area. If you're looking for a minor to modest boost in Girth, something relatively safe & non-surgical, and don't mind requiring top-offs every couple of years -- it's becomes a good option in my opinion.