Fascias of the male external genitalia and perineum

The fascias of the male external genitalia and perineum serve as surgical landmarks and are considered to act as initial barriers to urinary extravasation; thus they are of fundamental importance to the urologist and anatomist. There is little agreement, however, about the naming and function of these fascias because they have been defined inconsistently. The extensive use of eponyms for the fascias adds even further confusion to the proper nomenclature. Our findings, based upon dissection and magnetic resonance imaging (MRI), show that except for the single layer of dartos (smooth muscle) in the scrotum, there are two distinct layers of fascia in the penis and perineum that are continuous with each other and the anterior wall fascias. To minimize confusion, we conclude that the fascial layrs around the penis be termed the superficial and deep penile fascias, and those to which they are continuous in the perineum be termed the membranous layer of the superficial perineal fascia (the fibrous stratum that traverses the superficial fascia) and the deep perineal fascia. Their presumed role in limiting urinary extravasation is based upon relatively few well‐detailed report and currently remains poorly understood. However, this may be improved upon in the future through combined application of clinical findings and MRI to individual cases of urinary extravasation. © 1994 Wiley‐Liss, Inc.