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
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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