This surgery and the related recovery expenses may be a pay out of your pocket scenario.
Overseas travel medical insurance comes with lots of fine print, loopholes, exacting steps or procedures to follow in the countries you are visiting, and exemptions. Read any policy to be bought for coverage limits.
Note that medical travel insurance seems to be for unexpected medical situations and existing medical ailments may be an exclusion. If you plan to have a procedure that may not be covered, including the related recovery costs.
So I do not have the definitive answer.
Seems to me that a regular medical insurance plan (not a travel medical plan) that covers this in the country you are going to is what should be sought. Even then, I wonder why an insurance company would be willing to provide coverage for something that will likely cost them more than what the premiums paid will be. Maybe there is a waiting period. Many dental plans make you wait for a year to get an expensive dental procedure covered, as an example.
Perhaps others have better information. Someone who has went overseas for the procedure would likely be better able to answer this question. Or someone in the insurance industry perhaps?
Good luck!