Transnasal spread of bupivacaine into the pterygopalatine fossa following endoscopically assisted cotton swab placement: a cadaveric study

These findings demonstrate that bupivacaine can reach the pterygopalatine fossa from the nasal cavity when topically applied near the sphenopalatine foramen under endoscopic assistance, supporting the feasibility of such an approach. They also suggest the main mean of transport is simple diffusion, meaning that optimizing bupivacaine concentration, duration of application, and precise placement of the absorbent cotton ball are crucial for maximizing the block's clinical efficacy.