Evaluation of factors associated with recurrence in 47 cats undergoing balloon dilation for nasopharyngeal stenosis.

ObjectivesThis study aimed to evaluate factors associated with recurrence of clinical signs after balloon dilation in cats with nasopharyngeal stenosis (NPS).MethodsA retrospective multicentre study was conducted using data collected from the medical records of cats treated for NPS using balloon dilation. A total of 47 cats, each with a follow-up period of ⩾180 days, were included in the analysis of progression-free interval (PFI) and hazard ratio (HR) using Kaplan-Meier and Cox proportional hazards analyses.ResultsMultiple balloon dilations were planned for 26/47 cats. In total, 14 cats received three procedures and 12 cats received two. The dilations were performed at a median interval of 35 days (interquartile range [IQR] 29-39, range 15-127), regardless of transient recurrence. A single dilation was planned for the remaining 21 cats. Recurrence after the final balloon dilation occurred in 18/47 (38%) cats; in these cases, the median time from the final dilation to recurrence was 42 days (IQR 18-142, range 6-2303). The median PFI was 2303 days (range 6-2704), with 6-month and 1-year recurrence-free rates of 70% and 65%, respectively. Multivariate analysis revealed that performing planned multiple dilations was the only variable associated with improved PFI (HR 0.06, 95% confidence interval [CI] 0.01-0.30; P < 0.001). Specifically, cats undergoing planned multiple dilations had higher 6-month (92% vs 43%) and 1-year (88% vs 38%) progression-free rates than those undergoing a single dilation. No significant correlation was observed between PFI and the number of balloon dilation treatments.Conclusions and relevanceBalloon dilation repeated two or three times, regardless of any recurrence of signs, may assist in the long-term resolution of NPS in some cases.