Page 94 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 6 · Brachycephalic airway disease

Treatment Technique for correction of stenotic nares
and resection of aberrant turbinates
VetBooks.ir Animals in severe respiratory distress need to be evalu- Surgical correction of stenotic nares can be performed at
ated quickly and intubated if respiratory arrest is immi-
a very early age (3–6 months). It significantly reduces
nent. Most animals respond to cold intravenous fluids,
sedation with acepromazine (0.01 mg/kg i.v.), oxygen
gression of other components of BAD (Harvey, 1982a;
supplementation and dexamethasone (0.05–0.1 mg/kg upper airway resistance and decreases the rate of pro-
i.v.) to decrease pharyngeal and laryngeal swelling. Lorinson et al., 1997; Huck et al., 2008). Several tech-
Intravenous access is mandatory in either case but niques have been described for correction of stenotic
should be obtained with as little restraint and stress to nares, using either scalpel blades, laser or electrosurgery.
the animal as possible (Reiter and Holt, 2012). Long-term However, in the authors’ experience, the use of excessive
treatment of BAD is aimed at reducing airway resistance thermal energy, such as that generated by electrocautery
and alleviating obstruction, either medically and/or and diode lasers, should be avoided because deep
sur gically (ter Haar, 2016b). Maintaining an appropriate thermal damage, scarring and constrictive wound healing
bodyweight and condition, a clean, fresh and cool are commonly seen sequelae.
environment and regular controlled exercise are advised. Patients are placed in sternal recumbency with the
Corticosteroids can be used to treat mucosal swelling, nose perpendicular to the table or slightly elevated.
whereas broad-spectrum antibiotics, based on culture Adequate cosmetic and functional results of ‘Trader’s
and sensitivity testing of tracheal aspirates/broncho- technique’, which involves amputation of the ventral
alveolar lavage samples, are indicated in cases with portion of the dorsal lateral nasal cartilage and healing by
(aspiration) pneumonia. Any pre- or postoperative gastro- second intention, have been reported in immature Shih
intestinal signs are aggressively treated with a proton Tzu dogs with stenotic nares (Huck et al., 2008; Schmiedt
pump inhibitor (omeprazole 0.7 mg/kg orally q24h), a and Creevy, 2012). In mature dogs, a lateral, vertical or
prokinetic (cisapride 0.2 mg/kg orally q8h or metoclo- horizontal wedge resection of the dorsal lateral cartilage
pramide constant rate infusion at 1–2 mg/kg/day i.v.) and can be performed (Venker-van Haagen, 2005; Schmiedt
an antacid (Poncet et al., 2005; Reiter and Holt, 2012; and Creevy, 2012). The authors recommend a modified
Roedler et al., 2013; Oechtering et al., 2016b). Maropitant horizontal wedge resection that includes a partial
(1 mg/kg s.c. q24h) is a neurokinin (NK 1) receptor antag- ala-vestibulectomy.
onist that may be useful in reducing the likelihood of A wedge extending deep into the cartilage is resected,
regurgitation during anaesthesia. The components of the following the outer curvature of the ala from its medial
syndrome that are amenable to surgical correction are dorsal-most aspect at the naris ventrally towards the
stenotic nares, aberrant turbinates, elongated soft palate, lateral aspect and back over the body of the naris, con-
everted laryngeal saccules and laryngeal collapse. necting the start and end of the incision (see Operative
Correction of stenotic nares and staphylectomy are Technique 6.1). A Beaver scalpel holder with a 6500
techniques that, provided they are executed meticulously, pointed blade allows accurate incision and determination
improve patient welfare significantly and are associated of adequate depth. The initial suture is then placed from
with minimal complications. These two procedures form the middle of the remaining ventromedial part of the ala to
the first-stage surgical treatment for patients affected the more dorsolateral aspect of the naris to open up the
by BAD and can be performed in animals as young nasal vestibule adequately and create a maximal opening
as 6 months of age (for instance, when presented for medially. Closure can be performed with 1–1.5 metric
neutering). (4/0–5/0 USP) monofilament absorbable suture material in
Nasal airway resistance can be significantly reduced a single layer using a simple interrupted suture pattern.
by resection of turbinates with laser under endoscopic Guided by preoperative cross-sectional imaging and
guidance laser-assisted turbinectomy (LATE) (Oechtering rhinoscopy, LATE using a diode can be used to remove
et al., 2016b). The complication rate associated with the aberrant conchae and enlarge the ventral nasal meatus
procedure in the hands of experienced surgeons appears (Oechtering et al., 2016a,b). These recent reports indicate
to be low (Oechtering, 2010; Oechtering et al., 2016b). A that this technique can reduce intranasal airway resist-
recent report evaluating the LATE procedure in Pugs that ance by approximately 50% in brachycephalic dogs when
had shown no or limited response to first-stage surgery performed by experienced surgeons. Grading of the
has indicated that turbinectomy results in a good out- degree of turbinate protrusion has recently been reported
come, as assessed with barometric plethysmography (Liu in English Bulldogs (Rooney, 2009; Rooney and Sargan,
et al., 2017). 2010; Palmer, 2012; Vilaplana Grosso et al., 2015). Pugs
Sacculectomy and laryngoplasty procedures (partial appear to have the most severe degree of turbinate pro-
laryngectomy, arytenoid lateralization) are associated trusion amongst the brachycephalic breeds. Currently,
with higher perioperative risks (see section on surgical the degree of protrusion that is clinically tolerated is
procedures), and therefore should only be employed unknown, but LATE has proven to be an effective treat-
if conservative treatment, in combination with the ment for intranasal obstruction, owing to a significant
aforementioned surgical techniques, does not result in reduction in the number of contact points. Based on pub-
a significant improvement, or should be reserved for lished results, morbidity and mortality rates asso ciated
those cases where they are deemed absolutely neces- with the procedure are low, and postoperative owner
sary to improve outcome. In appropriately selected questionnaires (Pohl et al., 2016) and plethysmographic
patients and when performed using magnifying loupes, assessment (Liu et al., 2017) indicate substantial improve-
or a sur gical microscope and using meticulous tech - ment. Whilst conchal regrowth after LATE is seen in
nique, bene ficial results can be obtained using saccu- most cases, it rarely leads to a need for revision
lectomy, in selected patients with grade 1 laryngeal surgery. A degree of regrowth may even be desirable as it
collapse, in particular, and occasionally in dogs with allows for an increased capacity to fulfil important physio -
severe malformations. logical functions (Schuenemann and Oechtering, 2014b).

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