Here a resource from the Medicare Claims Processing Manual that I believe supports ranking the bilateral procedure or procedure at the highest RVU as first listed or 100 percent of allowable.
Medicare Claims Processing Manual Chapter 12 - Physicians/Nonphysician Practitioners
Page 107-111
40.6 - Claims for Multiple Surgeries (Rev. 1, 10-01-03) B3-4826, B3-15038, B3-15056
6. Rank the surgeries subject to the standard multiple surgery rules (indicator “1”) in descending order by the Medicare fee schedule amount;
7. Base payment for each ranked procedure on the lower of the billed amount, or: • 100 percent of the fee schedule amount (Field 34 or 35) for the highest valued procedure; • 50 percent of the fee schedule amount for the second highest valued procedure; and • 25 percent of the fee schedule amount for the third through the fifth highest valued procedures;
8. If more than five procedures are billed, pay for the first five according to the rules listed in 5, 6, and 7 above and suspend the sixth and subsequent procedures for manual review and payment, if appropriate, “by report.” Payment determined on a “by report” basis for these codes should never be lower than 25 percent of the full payment amount;
9. For dates of service on or after January 1, 1995, new standard rules for pricing multiple surgeries apply. If Field 21 contains an indicator of “2,” these new standard rules apply (see items 10-12 below);
10. Rank the surgeries subject to the multiple surgery rules (indicator “2”) in descending order by the Medicare fee schedule amount;
11. Base payment for each ranked procedure (indicator “2”) on the lower of the billed amount: • 100 percent of the fee schedule amount (Field 34 or 35) for the highest valued procedure; and • 50 percent of the fee schedule amount for the second through the fifth highest valued procedures; or
15. If two or more multiple surgeries are of equal value, rank them in descending dollar order billed and base payment on the percentages listed above (i.e., 100 percent for the first billed procedure, 50 percent for the second, etc.);
16. If any of the multiple surgeries are bilateral surgeries, consider the bilateral procedure at 150 percent as one payment amount, rank this with the remaining procedures, and apply the appropriate multiple surgery reductions. See §40.7 for bilateral surgery payment instructions.);