Stephen J. Birchard DVM, MS, Diplomate ACVS

Saturday, May 10, 2014

Surgical Correction of Stenotic Nares: Or how to do a nose job in a brachycephalic dog.

Fig. 1: normal anatomy of the nose in a dog
From: Evans HE. The respiratory system. In Evans, HE, editor, Miller’s Anatomy of the Dog. 3rd edition, WB Saunders, 1993, pg. 464.
Stenotic nares are one aspect of brachycephalic syndrome, the upper airway obstructive disorder seen in brachycephalic dogs such as bulldogs, pugs, and Boston terriers. Stenotic nares are characterized by a malformation of the alar folds resulting in abnormally small nostrils.

The mobile portion of the external nares is comprised of 3 cartilages, the dorsal and ventral parietal cartilage and the accessory cartilage.  The alar fold (also called the wing of the nostril or the lateral cartilage) is the nasal structure that forms the lateral border of the nostril.(1)  This fold is collapsed medially in dogs with stenotic nares.  During inspiration, the alar fold may collapse further, causing complete occlusion of the nostril.

Surgical Procedure

Fig. 2: Wedge resection for correction of stenotic nares in brachycephalic dogs.
From: Fingland RB, Obstructive upper airway disorders, in: Saunders Manual of Small Animal Practice, 3rd ed., editors: Birchard SJ, Sherding RG, Elsevier, St. Louis, pg. 1651.
The surgical procedure to alleviate stenotic nares is either to remove a wedge of tissue from the alar fold, or to do a subtotal excision of the alar fold. The author usually performs the wedge excision technique which is described here. (Fig. 2) Position the animal in ventral recumbency with the head at the end of the operating table.  The nose is surgically prepared. A scalpel with #15 blade is used to make angled incisions in the alar fold so the portion to be removed in the shape of a triangle. (Fig. 3)
Fig. 3: Angled incisions made to begin triangular wedge excision of alar fold.
Be sure to include a pie-shaped section of cartilage from the inside of the alar fold in the excised section. Remove the tissue via sharp dissection.  Control hemorrhage with direct pressure.  Place simple interrupted sutures (4-0 Monocryl) in the alar fold, taking bites from inside the nostril to the outside (Fig 4). 
Fig. 4: direction of suture bites for closure of the alar fold after wedge excision.
Hemorrhage subsides after the sutures are placed. If the nostril does not appear adequately open, remove the sutures and excise more tissue from the either the lateral or medial aspect of the alar fold. Try to achieve symmetrical openings to the nostrils. (Figs. 5,6)
Fig. 5: Completed correction of one side of stenotic nares in a Shih Tzu
Fig. 6: Completion of both sides of correction of stenotic nares via wedge excision.
Postoperatively, keep the nostrils clean with moist sponges, and prevent self-mutilation with an Elizabethan collar if necessary.  Suture removal is not necessary since absorbable suture material is used.

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