What Can I Do to Prevent Columella Scarring After Rhinoplasty?

I did one of the first open rhinoplasties in the US more than 30 years ago. Then, the criticism was making a scar in the columella. That is the easiest part of rhinoplasty. If the surgeon can't make a almost non detectable scar, he should not be doing rhinoplasties.
Choose an experienced rhinoplastic surgeon and you won't have that problem.

I assume you are talking about the inverted 'V' shaped incision on the columella which is used for approach in open rhinoplasty technique. If that is correct, you don't have to do much. Those incisions heal very well. However, an infection or suboptimal closure of the wound can lead to scarring. If you see signs of any infection, such as redness, yellow drainage, pain on touching or fever, report to your physician immediately. In terms of good closure, you should be able to tell right away if the skin incision is level or not.
After your stitches come out, use Vitamin-E to rub on it morning and night for 3 months. That will improve the scar.
Regards

People spend an extraordinary about of time worrying about scaring and healing. The focus should really be on the final results instead of micromanaging your care. Leave that up to your surgeon. They don't want you to have a bad scar either, so they are going to do everything possible to help you have the best outcome. Good luck.

If you have an open rhinoplasty with an incision across the columella, this scar heals usually very well. Why? Because it is in a favorable place AND your experienced rhinoplasty surgeon will take special care with closure of the incision to avoid any aesthetically bothersome scar.
There are many things you could do for the scars but it may not change much of the overall outcome.

I don't recommend any special care for the columella incision associated with open-rhinoplasty. They heal practically invisibly in everybody, so don't worry about this.
Best regards. 

Yo may want to consider silicone gel.
Avoid sun exposure to the area.
I am not a big fan of Mederma.
Some advise taping of the scar but this can be inconvenient.
Gentle topical massage/pressure may also be beneficial.
As always discuss this with your surgeon prior to implementation as they may have strong feelings one way or the other.

Columella scars usually heal very well with little post-operative care.  The surgeon has to be careful with the dissection and closure.  You should not worry about what you have to be doing.

Columella scars after an open rhinoplasty usually heals very well.  Some use stair-step incisions, chevron incisions, and even straight across incisions.  I think that all do well for the most part.

 It is extremely rare to have a poor scar in the columellar region.  Some skill is required in placing the incision in the correct position as well as taking care not to injury this delicate tissue.  Using the correct plastic surgical technique will usually ensure a satisfactory scar.  

Having your surgeon use the best technique is vital to a great result and his skill will determine the amount of scarring that will take place. Along your incisions, you should always have the them covered with vaseline and I would avoid antibacterial ointment to avoid contact dermatitis that is very common after surgery.
Hydrogen peroxide can be used judiciously and with the guidance of your physician, but when used without careful regard, this agent can increase scarring. Your incisions should look like a very fine wrinkle and this is the goal. When they are fairly clean I would avoid hydrogen peroxide and use vinegar and water in a 1 to 3 dilution or less, depending on your discomfort.
Keeping the crusting to a minimum will decrease the bacterial load and lead to less scarring. After the first 2 weeks, you can then use a silicone based scar gel to cover the incision for the next three months. External incisions are what you should use your silicone gel for and not the internal incisions inside your nostril. Minor scar treatments can lead to the best result; a resurfacing 4-8 weeks after your procedure can help!