Hi XXXXXXXXX~
A laryngeal tie-back is a surgical procedure done to dogs who have laryngeal paralysis which often affects their breathing.
At the clinic where I work, we've done several of these in the last month...often on older, larger breeds who have their breathing compromised by the folds of the larynx. These dogs often sound hoarse when breathing and can have coughing spells that last for several minutes. The amount of oxygen in their blood is lower than normal because of the compromised air flow into the lungs.
You can find a lot of information on the procedure here:
http://www.vetsurgerycentral.com/laryngeal.htm
http://www.peteducation.com/article.cfm?c=2+2096&aid=861
In the dogs I've seen, the prognosis was very good, with all of the dogs having an improved breathing pattern after the surgery.
I hope this helps.
Certified Veterinary Technician
Associates Degree in Veterinary Technology. State and Nationally certified.