Treatment of eyelids and third eyelid tumors in dogs with radiosurgery: a preliminary study

INTRODUCTION: In canine eyelids surgery, intraoperative bleeding may obscure the surgical field and lead to increased swelling, bruising and pain. Therapies for the canine lids and nictitating membrane tumors include surgical excision, cryosurgery, or carbon dioxide laser ablation (Stades and Van der Woerdt, 2013). Potential disadvantages of cryosurgery are severe postoperative swelling, depigmentation and the unwanted loss of normal tissue. Laser requires safety precautions, including wavelength-specific eye wear and the hazard of beam scatter and or reflection. OBJECTIVE:to evaluate the efficacy of high-frequency radiowave surgery in treating tumors of eyelids and third eyelid in dogs. MATERIALS & METHODS: Seven dogs (7 eyes) referred with eyelids tumors and 3 dogs with third eyelid tumors were enrolled in the study over a 12-month period. Ablation was performed using high-frequency radiowave surgical unit (Ellman Surgitron FFPF) at a power setting on 2.5 (4 cases) or 5.0 (6 cases) with “needle electrode” (TA2B, TA3B, TA8B) or “empire microincision electrode (TEE305) in the Cut/Coag mode (5 cases: 2 eyelid papilloma and 3 third eyelid tumors) or cut mode (5 eyelid tumors). RESULTS: In all cases surgery was performed in a very short time with the advantage of an excellent haemostasis and minimum onset of oedema using both modes (cut or cut/coag). Surgical incisions were extremely precise and accurate. Two dogs with papilloma on the upper eyelid, treated with a needle electrode and a power setting on 3.0 2,5 showed dehiscence of the surgical wound one week postoperatively. One dog with melanocitoma of the third eyelid showed transient depigmentation of the inferior eyelid which resolved after two months. In all other cases (2 meibomian gland carcinomas, 2 adenomas and 3 2 epitheliomas) no notable complications were observed and the results of the scar was judged as good by surgeons and dog's owners. Follow-up (up to 1 year) showed no recurrence in any case. DISCUSSION AND CONCLUSION: To the authors’ knowledge, treatment of eyelid and third eyelid tumors with high-frequency radiowave surgery is not wide described in dogs and there are not published clinical studies. Results of this study demonstrated that it may be a simple, safe and effective surgical treatment for eyelids and third eyelids tumors in dogs. Dehiscence of surgical wound after the excision of an eyelid papilloma in two cases could be due to the use of low power setting in cut/coag mode. At this setting, a less precise incision and a slower passage through the tissue were achieved, increasing tissue damage and delaying healing. In the same way, needle electrodes with cut/coag mode, used for third eyelid excision in a dog, could have caused a minimal amounts of lateral heat, responsible of depigmentation of the inferior eyelid margin. The “empire microincision electrodes” produce a high concentration of energy with the least amount of thermal damage to adjacent tissue. Therefore, they are the optimal electrodes for eyelid surgery. This technique offers potential advantages over some others in use, like CO2 laser, including minimal safety precautions, self cleansing and relatively low cost. Choosing optimal power settings and the correct electrode will prevent increased tissue damage.