Do not use the open code for procedure when performing the service laparoscopically.  Use an unlisted code if none exists.  Contact your medical society and the CPT® committee to describe the service and advocate for a code.

Here is Nancy Maguire's response to this question on the Q&A forum:

For any "unlisted" code the payer will conduct a review to see:
- Whether the procedure or service requested by an unlisted code actually has a specific CPT® code that is more appropriate.   An unlisted code must be medically necessary. This would include determinations of whether:
- There is a medical problem,
- The procedure is appropriate to address the problem, 
- The procedure is of proven efficacy, and/or the standard of care
- Whether the site of service requested is appropriate
The coder should also review the Category III codes before assigning an unlisted code.  If a Category III code is available, it must be assigned.

Do not recommend submitting an "open" code because that is not the technique described.

If there is another code that is similar to the one you are submitting as an unlisted code, let the payer know that in your cover letter. That will help with pricing.