What is the most common complication with a PSA nerve block?

• A. Hematoma
• B. Infection
• C. Nerve injury
• D. Pain on injection

Answer: (A)

When a PSA nerve block is performed, the area around the maxillary tuberosity contains a dense network of veins, notably the pterygoid venous plexus. If a small vessel is nicked during needle advancement or needle withdrawal, blood can track into the soft tissues to produce a hematoma. This makes hematoma the most common complication of this block.

Other issues like pain on injection can occur but are not as consistently encountered as hematoma, infection is relatively rare in this clean procedure, and nerve injury is uncommon because the injection targets the nerve bundle rather than a delicate nerve structure. To reduce risk, aspirate before injection, inject slowly in small increments, and apply pressure if a hematoma starts to form.