Assessment of the potential efficacy of blind perineural injection techniques for blockade of the saphenous, obturator, and lateral cutaneous femoral nerves in dog cadavers.

OBJECTIVE To evaluate the potential efficacy of blind perineural injection techniques to provide nerve blockade of the saphenous, obturator, and lateral cutaneous femoral nerves by assessing the distribution along those nerves of 3 volumes of an injected staining solution in dog cadavers. ANIMALS 18 canine cadavers. PROCEDURES The anatomic characteristics of the target nerves were evaluated by dissection in 3 cadavers. The saphenous nerve was located by the use of superficial anatomic landmarks and a loss-of-resistance test. The obturator and lateral cutaneous femoral nerves were located by the use of superficial anatomic landmarks. Following perineural administration of 3 volumes (0.1, 0.2, and 0.3 mL/kg) of staining solution near the target nerves in 15 cadavers, the distribution of the staining solution along the nerves was evaluated. Staining that extended ≥ 2 cm along the target nerves was considered to be compatible with an effective clinical nerve block. RESULTS In all cadavers, nerves were appropriately stained by the blind techniques used here. The staining distribution along the nerves was considered to be optimal after perineural injection of 0.2 mL of staining solution/kg in the obturator and lateral cutaneous femoral nerves and 0.3 mL of staining solution/kg in the saphenous nerve. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the evaluated blind perineural injection techniques may be an inexpensive, safe, and clinically effective method to block the saphenous, obturator, and lateral cutaneous femoral nerves in dogs.