How do doctors know if alarplasty will compromise breathing in a patient?

This is a judgement call based on exceptional training and alot of experience with nasal and alar base surgery. There is a fine line between narrowing the nose enough to produce an esthetic result and narrowing the nose too much and creating a nasal breathing problem. Seek a highly experienced rhinoplasty specialist for more specific advice.Stephen Weber MD, FACSDenver Facial Plastic Surgeon

   If you have valve collapse or weak support, that is assessed during the exam.  Otherwise, alar base reduction will not produce this result.Find a board certified plastic surgeon who performs hundreds
of rhinoplasties and rhinoplasty revisions each year. Then look at the
plastic surgeon's website before and after photo galleries to get a
sense of who can deliver the results. Kenneth Hughes, MD Los Angeles, CA

Alar reduction is a simple procedure that can be done under local anesthesia. Recovery is very quick. For mild alar reduction the incision is placed inside the nostril and scar is not visible. For larger reduction full thickness of the base of the ala is removed leaving a thin scar at the base of the nostril. For an experienced surgeon it is a simple measurment to remove just the right amount of tissue and avoid causing airway obstruction.

Consult with a Board Certified Plastic Surgeon who is very experienced in nasal surgery.  An exam is needed to assess your cartilage support.  Alar Base reduction should not compromise your breathing.