Micropenis is a multifactorial disorder caused by genetic, hormonal, and environmental abnormalities. It can also be associated with ambiguous genitalia or malformations such as hypospadias (an abnormal location of the urethral opening).
Hormones for penile growth
The essential hormones for penile growth are the androgens (male hormones) testosterone and dihydrotestosterone as well as luteinizing hormone (LH) from the pituitary gland. In the fetus, proper penile development depends on the conversion of testosterone into dihydrotestosterone by the enzyme 5-alpha reductase in the penis, testicles, scrotum, urethra, and prostate. This development also depends on the presence of intact, functional androgen receptors in the target cells in the internal and external genitalia.
Therefore any event or abnormality that inhibits androgen production or the action of 5-alpha reductase may lead to male genital underdevelopment. Exposure of a pregnant woman to hormone-disrupting industrial and agricultural chemicals, for example, can interfere with normal sexual differentiation in the fetus. Penile underdevelopment may also result from genetic mutation of the androgen receptors or from any congenital, LH-inhibiting anomaly of the hypothalamus or pituitary gland, as LH normally stimulates the testicles' Leydig cells to secrete testosterone.
Sometimes, despite normal levels of androgens, the genital tissue is insensitive to them, with the subsequent development of a micropenis that does not respond to testosterone administration. Shortening of the penis may also occur after surgeries such as radical prostatectomy (removal of the prostate and seminal vesicles) to treat prostate cancer or after insertion of penile prostheses to manage ED. And in a few cases, no evident cause for the micropenis is detected, despite a thorough workup.
Penis enlargement procedures
In adults, especially in a case of the man's dissatisfaction with the size of his penis and the ensuing development of severe psychological disturbances, management of the condition depends on the diagnosed causes. Treatment may involve psychiatric counseling; education; liposuction or lipectomy of the excess suprapubic fat; hormone replacement with testosterone or LH; and penile lengthening and/or widening through valid, approved microsurgical techniques performed by a team of expert urologists and plastic surgeons.
In cases of congenital or acquired micropenis - for example, complete or partial penile severance or destruction due to accident, injury, or surgical mishap - several procedures have been effective. With myocutaneous flaps (portions of muscle and skin taken from the upper arm or lower abdomen, with preservation of the nerves), it is possible to add about 2 - 3 inches to the penile length, or even to create a new penis. A novel procedure using bilateral flaps of the saphenous vein to increase penile girth has also yielded encouraging results.
Even in patients with amputated penises - self-inflicted by mentally disturbed men, or suffered in an accident or at the hands of a jealous or abused wife or mistress - the majority of cases can be treated successfully by microsurgical reattachment, or alternatively, by the creation or reconstruction of a new, functional penis using grafts. More than 50 such cases have been reported in the medical literature.
In cases of penile shortening postprostatectomy, daily use of a vacuum device without the constricting ring may contribute to reelongation. Other surgical techniques for penile lengthening include the Perovic procedure, which involves penile disassembly, with dissection of the glans penis off the corpora cavernosa and the insertion of a piece of the costal cartilage into the distal corpora; or subcutaneous bulking of the penis with fat, free dermal fat flaps, or biodegradable material. A recent study involving the use of a biodegradable scaffold seeded with fibroblasts configured into a tube and wrapped around the penile shaft yielded good results, with about a 3 cm increase in girth.