To investigate whether prostate size influences periprostatic nerve distribution (PND). Recent studies have revealed variable sPND. No investigations have been done concerning potential factors that might affect anatomic variability.

Whole mount sections (base, middle, and apex) of 45 prostates after non-nerve-sparing endoscopic extraperitoneal radical prostatectomy were immunohistochemically stained against autonomic nerve fibers. Nerve quantification and computerized planimetry of the total nerve surface area (ImageJ software) were performed within defined regions: ventral, ventrolateral, dorsolateral, and dorsal . Two groups were defined (group 1, < 30 cm; group 2, ≥ 30 cm).

A total of 24 prostates were assigned to group 1 (median volume 21 cm (range 19-29)) and 21 to group 2 (40 cm (range 33-75)). In all specimens, the greatest percentage of nerve surface area was in the dorsolateral region, but it varied: ≤48% and ≤45.5% was found in the ventrolateral (VL) and the dorsal (D) regions, respectively. No difference was found in the PND within the different regions between the 2 groups. In all specimens, the median number of counted nerves at the base, middle, and apex were 143, 141, and 131, respectively (P = .26), but the median total nerve surface area decreased significantly (6.452, 3.975, and 2.093 mm², respectively; P < .001).

The PND varies, with high percentages in the VL and D regions in some cases. No difference was found in the PND among prostates of different sizes as defined in our study. These anatomic findings should be considered in patients qualifying for nerve-sparing prostatectomy.