Rigid Endoscopy to Aid the Treatment of Cervical Mucocele in a Dog.

Background: Sialocele or salivary mucocele is the accumulation of saliva in the glandular connective tissue due to a leakage from damaged salivary duct, which is surrounded by granulation tissue. The mucocele can be classified according to its location (cervical, pharyngeal or sublingual, the latter being known as ranula). The treatment consists of salivary gland and duct excision. However, in some cases, the definition of which side is affected is a challenge for surgeons. Keeping this in view, the aim of the present study was to describe the use of rigid endoscopy to determine the affected gland in a dog with cervical mucocele. Case: A five-year-old Dachshund, weighting 8.2 kg, was presenting progressive swelling in the ventral cervical area. The animal presented apathy, appetite loss and saliva drooling. A fluctuant, non-painful, fluid filled mass was noted on physical examination. Sialocele was diagnosed and surgery was undertaken to excise the involved gland and mass. The patient was positioned in dorsal recumbence. A skin incision was performed in the cranial-ventral aspect of the mass as it was not possible to precise the affected side. Following drainage of the content, the inner aspect of the sialocele capsule was digitally palpated using the surgeon's index finger. However, it was still not possible to determinate the affected side. A purse-string suture was performed around the incision and a 10mm cannula was inserted into the sialocele lumen. The cavity was insufflated with CO₂, then using a 0° 10 mm endoscope, the whole extension of the capsule was inspected. On the right side, the wall was round shaped, suggesting the presence of the right gland compressing the wall of the affected gland to the left. On the left side, there were some recesses and irregular surfaces, and an orifice was identified, suggesting the presence of the ducts opening. Therefore, the left sublingual and mandibular glands were excised conventionally. The procedure lasted 150 min and it was performed uneventfully. The patient was followed-up for seven days and skin sutures were removed after complete primary intention healing. Thirty days postoperative the patient presented no signs of recurrence. Discussion: Although several maneuvers were performed in order to diagnose the affected side in the current report, some doubt remained. Thus, endoscopic diagnosis was tested, which has not been reported for that purpose in the author's knowledge. Although not completely conclusive, such examination provided strong basis that the left side was affected. A month after the treatment, recurrence did not occur, which is usually one of the most common complications. Therefore, the exam purposed in this report fulfilled its expectancies, suggesting that rigid endoscopy may be used as a new tool for identification of which side and gland are involved in complicated extensive salivary mucoceles cases. Another important aspect of the procedure was the insufflation of the mucocele cavity that allowed the inner capsule inspection and did not result in subcutaneous emphysema. It was applied a pressure of 15 mmHg, higher than routinely used for laparoscopy in dogs, since it is a limited region, and presents reduced risk of subcutaneous absorption or alteration by compression. In conclusion, endoscopic view of the sialocele inner capsule is feasible in dogs as an adjunct for diagnosing the affected side in complicated cases. [ABSTRACT FROM AUTHOR]