Cutaneous distributions of genitofemoral and ilioinguinal nerves to pubic, perineal and ventromedial thigh regions in Thais.

Objective: To determine the cutaneous distributions of genitofemoral (Gf) and ilioinguinal (Ig) nerves to pubic, perineal and ventromedial thigh regions in Thais. Methods: The present study was performed bilaterally in 98 halves of 49 embalmed cadavers. The cutaneous distributions of the Gf and/or Ig nerves to these regions were dissected, identified and recorded. Results: Based on the cutaneous distributions of Gf and/or Ig to pubic, perineal, and ventromedial thigh regions, five different types of cutaneous branching patterns of both nerves were identified. Type A (18.28% of cases) had only the branches of Gf to the mons pubis, anteroproximal part of the root of penis, the scrotal or labial and the ventromedial thigh regions but in type B (21.51% of cases) had only the branches of Ig to these regions. The most frequent type of these innervations was type C (39.78% of cases) with dominance of both nerves branching to these regions. In type D (8.60% of cases), having the branches of both nerves but with a dominance of Gf, consisted of 2 subtypes D-1 (2.15% of cases) and D-2 (6.45% of cases). In contrast to type D, type E (11.83% of cases) having the branches of both nerves but with a dominance of Ig, consisted of 2 subtypes E-1 (8.60% of cases) and E-2 (3.23% of cases). Conclusions: These findings would provide the marked anatomic variability of Gf and/or Ig nerves in pubic, perineal and ventromedial thigh regions in Thais, and may assist diagnosis, anesthetic nerve block and prevention nerve damage during surgery.