After 30+ years of drinking, the latter 10 of which were extremely heavy drinking, I quit in 2004. I was certain my liver was severely damaged. I had pain in my abdomen, in my lower back, my eyes had a slightly yellow color and so on.
I was certain I was a goner, my father had died from liver problems, which made me doubly certain. I was so paranoid to even go to a doctor to get the bad news that I was sure I was going to hear, I waited for almost a year and a half sober to go for blood work. Terrified the whole time that the results would be bad.
I finally went, sweated it out for several days while the lab did it's thing. The results came back perfectly normal. Not even slightly elevated. I spent a year and a half agonizing over nothing.
I eventually relapsed after 8.5 years sober. But back on track with 9 months now.
If my liver was OK, with my history, there's something to be said for the resiliency of the organ.