Opps, it actually 4.2cm....
4.5 millimeters (MM) or centimeters (cm)?
Thanks for clariying the size!
PEI is not widely used. Would consider consultation with Lisa Orloff at UCSF to review options - she can do ultrasound to see if PEI would be an option, and may know of someone in the area who can do the procedure (if she does not). She's also a great surgeon and ultrasound-clinician.
PEI can cause extravasation into surrounding neck tissue and can damage the nerve that goes to the vocal cord - this is rare in expert hands.
Dr Guttler in Santa Monica does these procedures, but he is not close by....