# 69644 vs 69646



## allyash333 (Mar 17, 2017)

Hi!  
I am hoping someone can help me with this.  I am trying figure out the specific differences between 69644 and 69646.  I know that what CPT and CDR say however when I'm looking at the op report and the side by side descriptions in the CDR I'm having a hard time distinguishing between the two.  

This is not a specialty that I have experience in coding, I just had a project dumped in my lap so any advice would be greatly appreciated!!

Thank you!!


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## nsteinhauser (Mar 17, 2017)

69644 is a "canal wall up" approach mastoidectomy.  69646 is a "canal wall down" approach for the mastoidectomy.  Both of these codes include ossicular chain reconstruction.   
From "Otolaryngology Coding Alert" May 2010:
"In the "canal wall down" mastoid procedure, the surgeon removes the bony posterior external auditory canal.  The surgeon performs the steps of the canal wall up mastoidectomy and then drills away the superior and posterior canal wall to the level of the facial nerve, which is identified and left with a thin plate of bone covering it, says Cobuzzi.  This approach offers the widest access to the middle ear, antrum, and attic, as well as the mastoid."
Hope that helps.


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## allyash333 (Mar 17, 2017)

Yes it does!!  Thank you so much!


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