Why is a columella strut used?

This has a name: very deep lack of self-confidence of surgeons lacking experience, which leads them to an abuse of interventionism, unnecessarily complex (and expensive) procedures and donor site waste and morbidity. 

In other words: the surgeon has no remote idea if the tip needs a strut or not, so... considering the strut provides no major harm itself (if properly executed).... let's use it! rather than regretting not using it. The worst of this policy is the "side effects", since struts are very aggressive tools at the columella, providing extraordinary degrees of tip projection and support, tightly connected with a risk of fake looking noses, over projected tips, etc. Performing surgical gestures on noses without criterion sooner or later leads to poor results or deformities.

As rhinoplasty revision surgeon I can tell you 80% of cases I receive are due to wrong indications, poor surgical planning and execution, and majoritarily abscence of key gestures (missing osteotomies, grafting, etc); however there is a group of non-sense poor cases in which you have no remote idea why the previous surgeon did this or that, applied such graft or performed such maneouver... it seems to me like random attemps to "play with a Guinea's pig and let's see what happens" without any understandable logic.





As rhinoplasty surgeon you have to predict the viscoelastic behaviour of the nose you are operating on, and deem indicated or not any additional suport or re-structuring gestures, grafting, etc.





Surgeons graft-it-all style, surgeons open-them-all style... just convey their own unreliability to their techniques.

The main purpose of columellar struts, particularly of the tip cartilages are taken apart, is to support the projection of the nasal tip after surgery. An open rhinoplasty causes scar contracture and potentially tip blunting long term.