It’s amazing, man took eons to learn how to heal a heart, a physical transition from illness to becoming healthy. But, there are two types of heart surgery. ~ Lisa Blair

The heart surgery in Ezekiel 36:26 ESV is speaking about a spiritual heart surgery. This is not specific to a physical failure of the heart, the muscle is fine, it is speaking about our transition from our old way of living to our new life. Ezekiel was a priest and prophet in the Old Testament who foretold the coming of Christ. Barnes’ Notes informs us that we (individuals) would move from the letter of the law to the spirit of the law, or to put it another way, we will move from the Old Testament Law to the Gospel of Christ. For new Bible readers, we moved from the Law of Moses to the Law of Jesus Christ, the Son of God.
Jamieson-Fausset-Brown Bible Commentary explains, our new heart creates a change in mind and will. It changes our spirit, our motives and principle of action. He further explains, a“stony heart—(is) unimpressible in serious things; like the “stony ground” (Mt 13:5, 20), unfit for receiving the good seed so as to bring forth fruit.
“(A) heart of flesh—(is) not “carnal” in opposition to “spiritual”; but impressible and docile, fit for receiving the good seed. In Eze 18:31 they are commanded, “Make you a new heart, and a new spirit.” Here God says, “A new heart will I give you, and a new spirit will I put within you.” Thus the responsibility of man, and the sovereign grace of God, are shown to be coexistent. Man cannot make himself a new heart unless God gives it (Php 2:12, 13).”
Spiritual heart surgery opens our hearts allowing the Holy Spirit and the individual (you) to live in relationship, to coexist together in our physical being. Our heart becomes a new house, it becomes a home. As with any home, there is family and a head of the family. Our head is the Holy Spirit who guides us, directs us, and corrects us. It is the quiet voice that we here saying, go this way, do not stray, do not go to the left or right, follow me.

Other Posts on this subject. lisasdailyinspirations.com
*The Trinity. May 30, 2019. https://lisasdailyinspirations.com/2019/05/30/the-trinity/
*Transforming Into the New You. March 1, 2021 https://lisasdailyinspirations.com/2021/03/01/transforming-into-the-new-you/
*Let the Spirit Lead. June 29, 2018. https://lisasdailyinspirations.com/tag/holy-spirit/
*Romans 8:9 The Holy Spirit Lives in Us. https://lisasdailyinspirations.com/2018/08/31/romans-89-the-holy-spirit-lives-in-us/
Images – Brady Gibson, YouVersion.Bible.com, Ezekiel 36:26. Isaiah 30:21, wiirocku.tumblr.com
Resource – Biblehub.com/commentary/Ezekiel 36:26, specifically Barnes Notes on the Bible and Jamieson-Fausset-Brown Bible Commentary.