The science behind the G-spot

I was surprised to read today that sexual cosmetic surgery is becoming commonplace. I'm not talking about boob-jobs either, but "enhancements" of genitals for increased sexual stimulation. Some of you may have heard of vaginal tightening surgery. I don't think it needs explanation. But I was completely unaware of the G-shot. The G-shot is an injection of collagen under the "G-spot" to create a bump for both enhanced stimulation and also, I imagine, making it easier to find. From the site:

"The G-Shot® is a painless office procedure performed in your doctor’s office under local anesthesia. The actual injection usually takes less than 8 seconds and the total office visit time is usually less than 30 minutes. A specially designed speculum is used to assist in the deliver a specified amount of human engineered collagen directly into the G-Spot after local anesthesia. The G-Shot® augments (enlarges) the G-Spot. This results in a G-Spot about the size of a quarter in width, and one fourth of an inch in height (meaning the projection into the vagina). Note that results do vary."

The patient which was interviewed for the story seemed utterly convinced, yet there must undeniably be a large component of placebo contributing to that success. Some woman swear by the G-spot while others are unfazed, but what does science have to say? A quick look on pubmed showed a surprising lack of studies in that area. Wikipedia mentions the inevitable female ejaculation and female prostate claims (skene glands), which, except for a particular study showing PSA and PDE5 staining in the putative area is not very convincing. In fact most studies and the official stance of the ob/gyn colleges agree with this general view:

"The G-spot is an allegedly highly erogenous area on the anterior wall of the human vagina. Since the concept first appeared in a popular book on human sexuality in 1982, the existence of the spot has become widely accepted, especially by the general public. This article reviews the behavioral, biochemical, and anatomic evidence for the reality of the G-spot, which includes claims about the nature of female ejaculation. The evidence is far too weak to support the reality of the G-spot. Specifically, anecdotal observations and case studies made on the basis of a tiny number of subjects are not supported by subsequent anatomic and biochemical studies."

unfortunately the g-shot studies do not seem to be peer-reviewed or publicaly available which makes it impossible to verify their claims: "•In a pilot study, 87% of women (as described above) reported enhanced sexual arousal/gratification. • Results can last for up to 4 months, and do vary."