It said "the team considered cases successful if the horses stopped cribbing for a year or longer after surgery" and "Of those 90, 76 horses (84.4%) stopped cribbing for at least one year following the procedure" and "Forty-six mares and 73 male horses underwent surgery during the study period" and "they performed a retrospective study on 119 cases from 1994 to 2012"

So it's safe to presume that for some horses it lasted longer than a year and even a lot longer than that. But "their success rates for effectively controlling cribbing vary".

I'd take it that if you've a horse that has recently started cribbing or has been doing it less than 3 years and it's so bad that it's colicing or wearing it's teeth down or losing weight and you've already changed it's diet and management regime so it's not stressed and you've ruled out other health problems and checked for ulcers but everything has failed that it might be worth chancing surgery and giving the horse a chance.