Punch Resection Alaplasty Technique in Dogs and Cats With Stenotic Nares: 14 Cases
Punch resection alaplasty is a previously unreported surgical technique for the management of stenotic nares. Nine dogs underwent the procedure in conjunction with soft palate resection and/or laryngeal sacculectomy. Three dogs and two cats were treated with the novel punch resection alaplasty technique alone. Symmetrical resection was achieved, providing excellent cosmesis. Good to excellent results were achieved in all cases, with owners feeling that their pet’s overall well being was improved following surgery.
Introduction
Brachycephalic airway syndrome (BAS) is a common respiratory disease in brachycephalic breeds of dogs and cats. The syndrome usually includes a collection of anatomical variances including stenotic nares, an elongated soft palate, and eversion of the laryngeal saccules. Tracheal hypoplasia and various stages of laryngeal collapse, as well as narrowing of the rima epiglottis, are further developmental changes that occur in animals with BAS.1–5 Stenotic nares and elongated soft palate are considered primary anatomical components of BAS, while laryngeal saccule eversion, laryngeal collapse, and rima epiglottis narrowing are considered secondary.6,7 Brachycephalic breeds such as the shih tzu, Pekingese, English bulldog, French bulldog, Lhasa apso, boxer, pug, and Boston terrier are predisposed to BAS, because the compressed skull increases airway resistance. These breeds also tend to have poorly developed nares and a distended nasopharynx.8 The skull in brachycephalic breeds develops abnormally; the width is normal but length is reduced. The cartilage plates of the nares are short, thick, and displaced medially.6 Excessive upper airway negative pressure is generated upon inspiration because of the stenotic nares. This causes inflammation and stretching of soft tissues, with eventual eversion of the laryngeal saccules and differing stages of laryngeal collapse.6–8 Early correction of stenotic nares has been recommended in affected animals, as it can either decrease or prevent development of additional airway changes by arresting tissue irritation and mucosal hypertrophy.2,7 An elongated soft palate and everted laryngeal saccules can occur independent of stenotic nares.7
Stenotic nares are more common in dogs than in cats. Lorinson et al reported that in their study, stenotic nares were present in 40% of the 118 dogs with BAS; Riecks et al noted stenotic nares in 58.1% of 62 dogs with BAS; and Torrez et al observed stenotic nares in 42.5% of the studied 73 dogs with BAS.9–11 The English bulldog was the most common breed affected in the Lorinson and Riecks studies, while the pug was the most common breed in Torrez’s study.9–11 In contrast to reports of dogs, literature reports of cats with stenotic nares are limited. An investigation by Henderson et al regarding causes of nasal disease in cats revealed that only two (2.6%) of 77 cases were attributable to stenotic nares.12
A single case report and several unreported cases discussed by veterinarians on the Veterinary Information Network describe conventional alaplasty techniques as viable treatments for cats with stenotic nares.13,14 Current treatment options for stenotic nares in dogs and cats include wedge resection alaplasty (horizontal, vertical, and lateral), nares amputation, and alapexy. The purpose of this paper is to describe a novel resection alaplasty technique using a dermatological biopsy punch tool, which achieves consistently effective and cosmetic results in both dogs and cats with stenotic nares.
Materials and Methods
Records were reviewed for cases in which the punch resection alaplasty technique was performed for correction of stenotic nares at California Veterinary Specialists between May 2006 and December 2008. All cases demonstrated clinical signs of increased upper airway resistance that could be attributed to stenotic nares, with or without an elongated soft palate and/or everted laryngeal saccules. Nine dogs had the punch resection alaplasty technique performed in conjunction with soft palate resection and/or laryngeal sacculectomy. These included six English bulldogs, two pugs, and one Boston terrier. Two shih tzu puppies from the same litter, one pug, and two unrelated adult Himalayan cats were treated with the punch resection alaplasty technique performed alone.
Signalments, chief complaints, diagnoses, surgical procedures, results, and follow-up intervals were reviewed for all 14 cases. All cases in the study had complete physical examinations, preoperative laboratory tests, and thoracic radiographs. The laboratory tests included complete blood count, serum biochemical profile, and urinalysis.
Surgical Procedure
Every case diagnosed with stenotic nares was also evaluated for other signs of BAS. Laryngeal examination was performed either at the time of surgery or during a previous hospital visit and was conducted while the animal was sedated with propofola (4 mg/kg intravenously [IV]).
At the time of surgery, dogs were premedicated with hydromorphoneb (0.1 mg/kg IV) by itself or in combination with acepromazinec (0.02 mg/kg IV). Both cats were pre-medicated using hydromorphoneb (0.05 mg/kg IV) and acepromazinec (0.01 mg/kg IV). Induction was then performed in all animals using propofola (4 mg/kg IV) and diazepamd (0.1 mg/kg IV). After intubation was achieved, all cases were maintained on isoflurane.e A presurgical clip was not performed; however, the nares were surgically prepared with a diluted Betadine solution. Visual examination of the nares was performed prior to surgery in all cases [Figure 1]. The alar fold was gently grasped for control, and a variably sized dermatological punch toolf was used to create a symmetrical, circular plug of tissue in the ala nasi (i.e., wing of the nose) to the level of the alar fold [Figures 2A–2E]. Typical sizes of the punch biopsy instruments used with these animals were 2 mm (for the cats and puppies) and 3 to 6 mm (for the dogs). A sufficient opening of the nares was created by using a punch that left a 2- to 3-mm rim of tissue medial and lateral to the resected tissue [Figure 3]. The tissue plugs were grasped using thumb forceps, and they were resected with Metzenbaum scissors after application of gentle traction. Hemorrhage was minimal and controlled by applying digital pressure or using epinephrine-impregnated cotton swabs.g The tissue edges were apposed using either 3-0 or 4-0 polydioxanoneh suture in a simple interrupted pattern. Usually two to three sutures were placed, depending on the size of the dermatological punch tool used [Figure 4].
Postoperative Care and Follow-up
All animals were recovered in an oxygen cage, and they received postoperative analgesia consisting of a Fentanyl patch,i hydromorphoneb (0.1 mg/kg IV), or buprenorphinej (0.01 mg/kg IV). Dexamethasone SPk (0.5 mg/kg IV) was administered at two separate intervals: once at the time of surgery and again 2 hours after completion of surgery. Elizabethan collars were placed on those animals that tolerated them, to prevent rubbing or pawing at the nares. In compliant cases, external sutures were removed 14 days postoperatively. In noncompliant cases, sutures were not removed and instead were left to dissolve and fall out. Animals were reevaluated at 14 days postoperatively and again at time periods ranging from 2 weeks to 28.5 months postoperatively.
Owners were contacted by telephone for follow-up information. A short series of questions were asked to determine the animal’s postoperative status [Table 1]. Maintenance of proper ala nasi position was evaluated at 2 and 6 weeks in all cases. A successful procedure was based on the ala nasi being maintained in abduction and a good to excellent owner’s assessment score. If stenosis of the nares reoccurred or owner’s assessment score was poor to fair, then surgery was deemed unsuccessful. Length of the follow-up period was 1 month to 29 months (mean 12.9 months).
Results
Clinical information, surgical results, and follow-up times for cases are listed in Table 2. The punch resection alaplasty technique was successful in all 12 dogs and both cats based on the ala nasi being maintained in abduction and a good to excellent owner’s assessment score postoperatively. We did not observe any cases of failed stenotic nares correction. Healing of the surgical site was complete by 14 days in all cases, with no reported or observed complications.
Two dogs required supplemental oxygen therapy for >6 hours postoperatively. Both of these cases had soft palate resection and laryngeal sacculectomy in addition to the punch resection alaplasty, and they were weaned back to room air within 24 hours. These dogs were placed in oxygen postoperatively for further supportive care as a precautionary measure, as they were considered more of a high risk during the recovery period. Following discharge, all animals recovered uneventfully and had no recurrence of stenosis. As noted by the owners and upon recheck evaluation, respiratory effort was decreased in all cases postoperatively.
Discussion
Stenotic nares and elongated soft palate are primary anatomical components of BAS, while everted laryngeal saccules and various stages of laryngeal collapse are considered secondary components of BAS.6 Hypoplastic trachea and narrowed rima epiglottis have also been described as secondary components. Terminology has created confusion regarding the anatomy of the nose. Terms such as lateral cartilage, wing of the nostril, lateral lip of the nostril, alar fold, and alar cartilage have been used to describe the mobile portion of the nostril.15 The nares are the openings of the external nose. They are covered by a thick, hairless epithelium externally and mucosa internally. Nasal cartilage plates are present under the epithelium. In brachycephalic breeds, these plates are short, thick, and positioned medially.6 The nasal cartilages include the unpaired septal cartilage, the paired dorsal and ventral lateral cartilages, and the paired accessory cartilages.16 Related to the ventral part of the septal cartilage is the vomeronasal cartilage.16 The alar fold is an extension of the ventral nasal concha or maxilloturbinate. It terminates within the vestibule by the bulbous enlargement that fuses to the wing of the nostril, also referred to as the ala nasi, which is the thickened dorsolateral portion of the nostril. The ala nasi contains much of the dorsolateral and accessory nasal cartilages. The wing of the nostril (ala nasi) is the mobile portion of the nostril17 and is used in this paper to describe the area of surgical correction.
Surgical procedures described to treat stenotic nares include amputation, wedge alaplasty techniques (vertical, horizontal, and lateral), and alapexy.4,6,18–24 Trader was the first to describe a technique in which amputation of the alar skin and underlying cartilage was performed.18 The procedure was performed with either a sharp incision or electro-cautery. The vertical technique involves removal of a wedge of tissue from the ala nasi, with extension of the incision caudally to include a portion of the alar cartilage.21,24 The nares are widened by narrowing the thickness of the alae, as well as by lifting the ala nasi. The horizontal technique was initially described by Leonard as an alternative procedure to amputation of the alae,20 in which the transverse diameter of the nostril is increased. Similar to the vertical technique, the horizontal technique also widens the nares by narrowing the thickness of the alae.21,24 Finally, the lateral technique involves removal of a portion of the caudolateral border of the ala nasi as well as a triangular section of skin adjacent to the ala nasi.6 Similar to the vertical technique, this lateral technique widens the nares by lifting the ala nasi.21,24
The alapexy technique opens the nares by creating a permanent abduction from a healed wound.15 Ellison described the technique for five cases in which previous alaplasty procedures had failed. Ellison suggests that wedge alaplasty techniques may fail because of the increased mobility of the dorsal lateral nasal cartilage. Flaccidity or medial drift of the ala nasi may also develop over time.1 The alapexy technique may be more suited for cases in which excessive flaccidity or drift of the ala nasi is expected postoperatively or is demonstrated preoperatively. Ellison reported successful outcomes in four (80%) of the five cases, although surgery times were longer compared to other wedge plasty techniques.15
Good to excellent results were reported in the present study using the newly described punch resection alaplasty technique. Eight of 10 adult dog owners reported excellent results, while the remaining two reported good results. The owners of the two puppies and both cat owners all reported excellent results.
Recently, Huck et al described the Trader technique for management of stenotic nares in immature shih tzus.19 In that paper, the authors recommended early surgical correction (amputation) of stenotic nares as an effective and cosmetic technique.19 Early surgical correction (in an animal aged 3 to 4 months) has also been recommended by other authors.2,7 The amputation technique has been reported to cause brisk bleeding. Also, because the resulting wound heals by granulation, epithelialization, and contraction, the initial wound may not be aesthetically pleasing until healing is complete.19 Although no scarring or discoloration was reported with the punch resection alaplasty technique described herein, previous reports using different techniques for management of stenotic nares have observed scarring and/or discoloration postoperatively. In our hospital, the immature shih tzus treated with this novel punch resection alaplasty technique had minimal hemorrhage and early primary healing of the incision. Both shih tzu owners reported that the dogs breathed more quietly with less effort and were more active beginning immediately after the procedure.
As stenotic nares are only part of BAS, all components of the syndrome should be evaluated and treated to ultimately provide successful outcomes. In our experience, the punch tool provided a symmetrical and more cosmetic postoperative appearance than other described techniques. The challenge of making appropriate incisions, particularly when faced with visual obstruction due to hemorrhage, was eliminated by this technique. With the punch resection alaplasty technique, in the infrequent cases when hemorrhage obscured the operative field, the tissue could be easily grasped and removed without difficulty or loss of symmetry. Similar to the vertical wedge alaplasty technique, the nares are widened by narrowing the thickness of the ala nasi. As with other alaplasty techniques providing sufficient widening of the nares, tissue is removed to the level of the alar fold. Flaccidity and medial drift are still possible but were not identified in the present study.
Conclusion
The punch resection alaplasty technique successfully corrected stenotic nares in 12 dogs and two cats. The simple technique achieved symmetrical cosmetic results. When combined with soft palate resection and laryngeal sacculectomy when indicated, the punch resection alaplasty technique also improved quality of life in all 14 animals. Punch resection alaplasty is an effective and appropriate technique for correction of stenotic nares.
Propofol; Teva Pharmaceuticals, North Wales, PA 19454
Hydromorphone; Baxter Healthcare Corp., Deerfield, IL 60015
Acepromazine; Phoenix Pharmaceutical, Inc., St. Joseph, MO 64507
Diazepam; Hospira, Inc., Lake Forest, IL 60045
Isoflurane; Medline Industries, Inc., Mundelein, IL 60060
Miltex sterile disposable biopsy punch; Miltex Instrument Co., Inc., Bethpage, NY 11714
Epinephrine; IMS Limited, So. El Monte, CA 91733
PDS II; Ethicon, Inc., Somerville, NJ 08876
Fentanyl patch; Watson Laboratories, Inc., Corona, CA 92880
Buprenorphine; Reckitt Benckiser Pharmaceuticals, Inc., Richmond, VA 23235
Dexamethasone SP; Phoenix Pharmaceutical, Inc., St. Joseph, MO 64507
Acknowledgments
The authors thank Stephanie Sydenstricker, RVT, for her help with data collection for this study.
Citation: Journal of the American Animal Hospital Association 46, 1; 10.5326/0460005
Citation: Journal of the American Animal Hospital Association 46, 1; 10.5326/0460005
Citation: Journal of the American Animal Hospital Association 46, 1; 10.5326/0460005
Citation: Journal of the American Animal Hospital Association 46, 1; 10.5326/0460005
Preoperative photograph of a pug (case no. 11) with bilateral stenotic nares.
Intraoperative photographs of the punch resection alaplasty technique. The ala nasi is grasped with Brown-Adson skin forceps. A 4-mm, dermatological skin biopsy punch is inserted perpendicular to the ali nasi and advanced caudally to create a plug of tissue. The plug of tissue is removed with Metzenbaum scissors, and hemorrhage is controlled with sterile cotton swabs (with or without epinephrine). Two to three simple interrupted sutures are placed to close the area of resected tissue.
Illustration depicting proper technique for removal of the skin plugs for the punch resection alaplasty. An appropriate size of tissue removal is indicated in white within the dotted line.
