All in a day’s work: CO₂ surgical lasers for multiple procedures

By Christopher J. Winkler, DVM, For The Education Center
Originally Published In Veterinary Practice News, February 2019 – Download as a PDF

In my practice, I’m often asked by clients if I might get multiple things done in a single procedure. In patients like Winston, who presented for neuter, the opportunity to prevent worsening of both brachycephalic airway syndrome (BAS) and a left third-eyelid gland prolapse should certainly be communicated and encouraged to the client.

Having a surgical laser can make such an undertaking possible in a single surgical visit. A CO₂ laser cauterizes blood vessels up to 0.5 mm in diameter as it incises, allowing excellent visualization of the tissues as the surgery proceeds, greatly reducing anesthesia time. The precise incision and control of hemostasis the laser provides are especially valuable in surgeries involving the airway and highly vascular areas such as the nose and eyelids.

The order in which the procedures were performed was chosen for benefits to the patient’s airway, and steps surrounding intubation for general anesthesia (1. elongated soft palate); sterility of the second procedure (2. orchiectomy); followed by continuing to improve the patient’s airway condition (3. stenotic nares). The third-eyelid procedure was thus undertaken last, as it was thought it could be reasonably postponed should the patient need to be recovered quickly. CO₂ surgical lasers are often equipped with air blowers flowing distally down the handpiece to prevent contamination to its tip and lens. This airflow should be shut off or otherwise disconnected during surgery of delicate tissues such as the third eyelid to avoid embolism. Petroleum-based ocular lubricants should be avoided when performing any laser eyelid surgery.

Pre-anesthesia

Preoperative bloodwork and cardiac auscultation were unremarkable. The patient was premedicated with dexmedetomidine 125 mcg/m² IM, cefovecin 8 mg/kg SQ, and carprofen 4.4 mg/kg SQ. The right eye was kept moist with petroleum-based lubricant, while the left was kept moist with periodic flushes of sterile water.

Laser equipment used

1. 45-watt VetScalpel CO₂ surgical laser (10.6 μm) with a flexible hollow waveguide and both adjustable and fixed tip (0.25-mm spot size) handpieces, with smoke evacuator attachment for soft palate resection.
2. Therapy laser (660, 800, 905, 970 nm) with handpiece in noncontact technique.

Anesthesia and surgical technique

Following propofol induction at 3 mg/kg IV, the patient was positioned in sternal recumbence with maxilla suspended from an IV pole with cling gauze. The soft palate was grasped via forceps and marked at the level of the epiglottis and caudal pole of the tonsils with the CO₂ laser at 0.4-mm spot size, 6-watt repeat pulse exposure (10 msec, five percent duty cycle) (Figure 1). The patient was intubated with a 6.5 endotracheal (ET) tube, and general anesthesia maintained with isoflurane. ET tube and airway were draped with moistened gauze to protect them from the laser. At 15-watt continuous wave exposure and 0.4-mm spot size, the soft palate was resected from the lateral marked edges medially, while constant tension was made on the forceps (Figure 2). No hemorrhaging was observed from incised edges.

Following removal of moist gauze from the airway, the patient was positioned in dorsal recumbence and clipped and prepped for a prescrotal approach. Testicles were approached with the laser at 0.25-mm spot size and 12-watt continuous wave exposure in SuperPulse mode (Figure 3). The laser was switched to non-SuperPulse mode to open the testicular tunics. Following the double-ligation of testicular vessels with absorbable suture, the vessels were incised at the same laser setting (Figure 4). The subcutaneous layer was closed with absorbable suture in a simple continuous pattern, and the skin closed with absorbable subcuticular sutures and Gluture. The neuter incision was then treated with a noncontact therapy laser at approximately 5 J/cm² per wavelength (Figure 5).

The patient was positioned in sternal recumbence with head propped up and ET tube and eyes draped with moistened towels (Figure 6). Stenotic nares were marked at 0.4-mm spot size and 4-watt repeat pulse exposure (10 msec, five percent duty cycle) in SuperPulse mode; both nares were marked at this time to compare either side prior to excision and reduce the time needed to program the laser for each excision. The alar folds were excised at 0.4-mm spot size and 10- watt continuous wave exposure (Figure 7). Moistened cotton-tipped applicators were used to wipe away char and then placed intranasally to protect the medial septum (Figure 8), as its damage could result in stricture formation. The alar cartilage was then ablated at the same laser setting, laterally to the moist cotton and proceeding rostrally to caudally until a cotton applicator could be advanced with ease into the nasal cavity.

The left eye was uncovered and flushed with sterile water, and the left globe draped in moistened gauze. The third eyelid was everted to reveal the bulbar conjunctiva. Gloves were changed, the CO₂ laser’s airflow turned off, and the adjustable handpiece replaced with a sterile fixed (0.25-mm spot size) handpiece. Incisions at 3-watt continuous wave exposure in SuperPulse mode were made on the caudal surface of the conjunctival mucosa between the gland and (parallel to) the lid margin of the third eyelid (Figure 9) and between the prolapsed gland and the bulbar conjunctival fornix (Figure 10) parallel to the first incision. No hemorrhaging was observed. A suture of 6-0 Vicryl was secured on the palpebral surface of the third eyelid and passed through to the bulbar conjunctiva. The incisions were closed with sutures over the gland in continuous horizontal mattress pattern (leaving incision edges open to allow tear flow) then passed through to the palpebral surface (preventing the suture knot from contacting the cornea) and secured again (Figure 11). The suture pattern may be repeated for additional security.

Postoperative care

The total anesthesia time was 90 minutes. The patient was administered atipamezole 250 mcg/kg and butorphanol 0.2 mg/kg. An e-collar was applied. The endotracheal tube should be checked for blood on extubation, and the patient monitored for epistaxis and dyspnea. Typically, these patients are very quiet during recovery. Winston experienced no complications during recovery and was discharged home later the same day with carprofen 37.5 mg PO BID and Neo-Poly- Dex ophthalmic solution OS TID for seven days. Winston was seen six days postsurgery, with excellent resolution of BAS (Figure 12). To date, he has had no recurrence of a prolapsed third eyelid.

A graduate of Ross University School of Veterinary Medicine, Christopher J. Winkler, DVM, DABLS, VMLSO, is the owner of Suffolk Veterinary Group Animal Wellness and Laser Surgery Center in Selden, Long Island, N.Y. He is certified in veterinary laser medicine and surgery by the American Board of Laser Surgery (ABLS) and is a certified veterinary medical laser safety officer and a faculty member of both the American Laser Study Club and the American Laser Medicine College and Board. Dr. Winkler is the editor and co-author of Laser Surgery in Veterinary Medicine, a forthcoming textbook due for release this month by Wiley-Blackwell (Figure 13).

This Education Center article was underwritten by Aesculight of Bothell, Wash., manufacturer of the only American-made CO₂ laser.