Is a columella tuck permanent, or is there always the possibility of it hanging again?

 The rhinoplasty procedure can address a hanging columella either as a stand-alone procedure, or as part of a full rhinoplasty. Once the columella has been  tucked upwards, it is permanent, not temporary. A columellar-plasty involves trimming back excess skin and cartilage inside the nose. For many examples, please see the video and  the link below

 A columellar tuckup is done by removing tissue, usually some septal cartilage and mucosa. With tissue removal the result obtained should be permanent.

Thanks for the question. Your surgeon is certainly correct. Not matter what change you are seeking with a rhinoplasty, there is some uncertainty. So a lifting of the columella is no different. It is likely to be improved, and you are likely to be satisfied with the result.