Wait for your denial letter, to see what it says to find out why.
Your description of your qualification is too short. The folks in this forum usually do self-evaluation and self-analysis. We show our qualifications according to the possible claims that we can make. Since we don't have Nobel Prizes, we need to fulfill at least three of the ten criteria. For research scholars here the possible claims are:
1. National or international award(s)
2. Memberships of professional associations
3. Authorship of scholarly work
4. Significant contributions to the field
5. Judge of others' work in the same field
6. Media report
Check out the USCIS website for the original description on the requirement of EB1EA. Check out the previous threads on the EB1EA qualifications. There are tons of them.
Your 'medical subspecialties, complexity of my job' doesn't seem to count into any of the above claims, no help. 'few publicatgions, few citations, couple of reviews of other books, journals, international presentations', that is too simple. It's hard for us to comment. It sounds like you don't care whether you qualify or not, or you don't know what you are dealing with. The quantity and quality of the publications, citations, reviews and presentations are very important! The USCIS could easily argue that all you described is what is required for a regular researcher. What you presented doesn't give them any reason to grant you EB1EA, since you just described a normal job of a normal scholar. Don't get offended. What I meant is that you need to show the evidence to the USCIS that you are superior, the top 1-2% in your field, to show them that your qualification satisfy the criteria. In another word, the petition letter and the evidence determines your case. The letters sound OK since you have 6 independent references. The content of the letters is very important for EB1EA. What you considered 'strong' letters may not be considered 'good' to the USCIS's eyes. Again, the letters need to show the evidence to support those criteria, otherwise, useless. In the support letters, simply saying you are top 1% in the field without any concrete evidences doesn't count anything, and it is 'not strong' in the USCIS's eyes.
I still remember a case: an Assistant Professor of mathematics who has more than 40 journal papers got denied in his EB1EA. Why?
Even though you go through the firm, still you need to keep an eye on what they do to your file. I suggest you to study the criteria of EB1EA, and study the petition letter the firm did. What criteria did the petition letter claim, what evidences did the letter use to support the claims, ... You may have a better idea from there, and we may help you from there if you show us the petition letter.
Lot of us did the self-petition in this way: collect the evidence to make the claims, we need to claim at least three of them. It's a word game in a sense.
Don't get discouraged too much. Once you learn, you know how to do it, by yourself.