However, there are a number of studies which have actually proven that most of the men who believe they have a small penis actually are normal-sized. The structure of the tissue of the corpus spongiosum is similar to that of the corpora cavernosa, but there is more smooth muscle and elastic tissue. Tissue grafts, such as dermal fat grafts or dermal matrix, can also be used for penis enlargement. The results of penis enlargement surgery vary among patients, but on average, patients can expect a Ѕ to ѕ inch increase in length and a 15-25% increase in circumference. Penis lengthening involves releasing the suspensory ligament at the base of the penis, allowing it to slide forward and increase its visible length. The most common and safest procedure for penis enlargement is to use injectable fillers. Penis enlargement surgery is an outpatient procedure that is performed under general anesthesia or twilight sleep. The skin over the penis is thin and loosely adherent and at the neck is folded forward over the glans for a variable distance to form the prepuce or foreskin.