Is it safe to do a posterior septectomy (posterior nasal septum resection) and to keep 1 cm of the septum anteriorly?

Hello, I've done a rhinoplasty two years ago but still have a trouble with breathing. My ENT said that the problem is that my nasal septum is very thick (1,3 cm) and suggests that he can do a posterior septectomy (resection of the posterior part of the nasal septum and keeping only 1 cm anteriorly).