By Dr. Daniel M. Core, DVM For The Education Center
Originally published in Veterinary Practice News – October 2013 – Download as a PDF
Dr. Daniel Core, DVM
Our hospital has used CO2 laser surgery in place of conventional cold steel procedures since 1999. CO2 lasers offer the veterinary surgeon the advantages of a precise surgical incision, reduced hemorrhage, pain and swelling, and minimal collateral damage.
CO2 laser surgery not only allows the veterinary surgeon increased proficiency in commonly performed procedures, but also enables him or her to do laser- specific procedures that were formerly referred out to specialists.
Stenotic nares are a common problem in brachycephalic breeds of dogs and cats. It is a congenital malformation of the nasal cartilage (Figure 1). Stenotic nares, along with elongated soft palate and everted laryngeal saccules, are components of brachycephalic obstructive airway syndrome (BOAS).
Patients with stenotic nares have nasal cartilage that lacks normal rigidity and collapses during inspiration, occluding the nares. The reduction in nasal airflow leads to greater inspiratory effort. The resulting dyspnea exacerbates elongated soft palate in affected individuals and can cause clinical BOAS.
Early recognition and surgical correction of stenotic nares, performed as early as 3 to 4 months of age, may decrease the severity of and possibly eliminate clinical BOAS.
CO2 Laser Surgery
The concept of stenotic nares surgery is based on the physics of airflow through the nasal passages. As the diameter of an airway increases, the flow rate increases proportionally to the cross sectional area of the airway. In other words, an increase in airway facilitates flow rate and results in diminished respiratory effort.
Conventional cold steel surgical repair of stenotic airways can be difficult due to hemorrhage. Due to obstructed view, the surgeon must be especially careful to excise equal size tissue segments on both sides and create symmetry. Cold steel procedure requires three to four sutures on both sides to reappose the tissues.[1, p.834] The procedure may leave scars (ibid.).
CO2 laser surgical repair of stenotic nares is bloodless, which provides clear view of the surgical field, thus allowing for precise surgical incision. The flexible fiber waveguide of our Aesculight CO2 laser is light-weight, easy to maneuver and thus ensures a better incision control. This laser procedure does not require suturing, brings an excellent aesthetic result, and leaves patients discomfort-free post-operatively.[2] The good time to perform CO2 laser stenotic nares correction is during a routine castration or ovariectomy without a significant increase in anesthesia time.
Anesthesia
General anesthesia is administered. Since patients with upper respiratory disease present significant anesthetic risks, special caution should be taken during sedation and intubation. For general anesthetic recommendations and selected anesthetic protocols.[1, pp. 818 and 833]
Positioning
The patient is positioned in sternal recumbency with the chin elevated. The planum nasale is scrubbed with antiseptic.[1]
CO2 Laser Settings
Incision marking: 2 watts in the continuous wave SuperPulse mode with a 0.25 mm-0.4 mm spot size (Figure 2a).
Excision of redundant tissue: 6-10 watts in the continuous wave SuperPulse mode with a 0.25 mm-0.4 mm spot size (Figure 2b).
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- Figure 2A
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- Figure 2B
Initial Incision
The proposed incision is marked with the laser at a very low setting (Figures 2a and 3-5).
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- Figure 3: Laser Marking Prior to Incision – Left Side
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- Figure 4: Symmetrical Laser Marking Prior to Incision – Right Side Using An Aesculight 0.4mm Laser Handpiece
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- Figure 5: Completed Laser Marking
Tissue Removal
A moistened Q-tip is inserted in the nares and serves as a back stop (Figure 6).
A dorso-lateral incision of the alar cartilage is preformed, while forceps are used to provide ventromedial traction. Note: Excision of the alar cartilage is strongly preferred to ablation, as it helps to prevent post-operative stricture.
The incision is continued proximally, which results in the removal of a cone or triangular section of tissue (Figure 6).
Repeat steps 1-3 on the contralateral side (Figure 7).
No suturing is necessary (Figure 8).
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- Figure 6: Excised Wedge of Alar Cartilage—Left Side
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- Figure 7: Excision Repeated on the Contralateral Side
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- Figure 8: Immediate Post-Operative View. No Suturing is Necessary
Post-Operative Instructions
Post-operative care is minimal and patients are discharged on the same day. If the tissue in the surgical site becomes overly dry, apply antibiotic ointment.
Summary
Stenotic nares are a key component of brachycephalic obstructive airway syndrome. Elective surgical intervention at an early age can minimize and sometimes completely eliminate clinical signs of BOAS. CO2 laser surgical correction of stenotic nares is simple and easy and yields a very gratifying cosmetic result. This procedure can be conveniently combined with a routine ovariectomy or castration without a significant increase in anesthesia time.
References
- Hedlund CS. Surgery of the Upper Respiratory Systems. In: Fossum TW (Ed). Small Animal Surgery, 3rd ed, St. Luis, MO: Elsevier/Mosby, 2007; 817–866.
- John C. Godbold Jr., Atlas of CO2 laser surgery procedures. Stonehaven Park Veterinary Hospital Laser Surgery Center, 2011.
All pictures Courtesy of Dr. Daniel Core, DVM
Dr. Daniel Core, DVM, is a small animal practitioner and owner of Airline Animal Health and Surgical Center in Bossier City, La. He graduated from Louisiana State University School of Veterinary Medicine in 1981 and completed a small animal internship at Auburn University School of Veterinary Medicine in 1982. He has lectured on CO2 laser surgery and therapy lasers. He is currently using his third CO2 laser.
This Education Center story was underwritten by Aesculight LLC of Bothell, Wash., manufacturer of the only American-made CO2 veterinary surgical laser.
