Creation of salpingopharyngeal fistulae for the management of guttural pouch tympany and persistent guttural pouch empyema

Case 1, Guttural pouch tympany An 8-month-old Arabian filly presented with a history of longstanding bilateral fluctuant parotid region swelling and acute onset dyspnoea, tachypnoea, inspiratory stridor and right mucopurulent nasal discharge. Endoscopy and drainage (mucopus from the right, air from the left) of the GPs resulted in temporary reduction in the bilateral parotid region swelling. Marked dyspnoea recurred 48 h later, with accompanying external GP distention. A diagnosis of bilateral (R > L) GP tympany with secondary guttural pouch empyema of the right GP was therefore made. An indwelling Foley catheter was positioned in the right GP, but the filly dislodged the catheter daily and after 5 days, surgery was performed. Case 2, Persistent guttural pouch empyema An 18-year-old pony gelding had chondroids found in the right GP 6 months previously and was diagnosed with a 'strangles' (Streptococcus equi var. equi) infection. Over subsequent months, multiple medical and surgical treatments were attempted but empyema kept recurring. After 6 months, it became difficult to introduce an endoscope into the right pouch, due to stenosis of the auditory tube. A laser salpingopharyngostomy procedure was recommended. Both horses underwent endoscopically guided salpingopharyngeal fistulation in the midline dorsal nasopharyngeal recess using a diode laser under standing sedation after topical application of local anaesthetic. A fistula approximately 1.5 x 2 cm was created (Figure 1) and then the median septum between the left and right pouches was resected caudally with the laser creating a large fenestration between the two pouches. No complications of surgery occurred. In Case 1, external GP distension resolved immediately following surgery. Re-examination at 6 weeks post-operatively showed continued patency of the fistula and resolution of secondary empyema. The foal remained asymptomatic thereafter until it was lost to follow-up. Case 2 had resolution of nasal discharge. A final follow-up endoscopy 3 months post-operatively revealed both pouches to be clear, and the salpingopharyngeal fistula to still be patent. Telephone follow-up 6 months post-surgery revealed that the pony had no recurrence of clinical signs.