Nonvisualization of Sialoliths during Sialendoscopy

Objectives Analyze the characteristics of patients undergoing interventional sialendoscopy for sialolithiasis whose stones were not visualized intraoperatively. Study Design Case series with chart review. Setting Tertiary care hospital. Subjects and Methods Patients (n = 276) undergoing sialendoscopy between June 2008 and December 2014 were reviewed for patient characteristics, imaging characteristics, and outcomes. Nonvisualization was defined as a sialolith that was documented on imaging preoperatively but not visualized intraoperatively during sialendoscopy, despite successful ductal cannulation and evaluation. Results A total of 337 sialendoscopy procedures were preformed. Preoperative imaging documented a sialolith in 203 (60%) cases. Nonvisualization occurred in 31 (15%) cases with sialolith. The parotid gland was involved in 58% (18 of 31) of nonvisualization cases, as opposed to 21% (43 of 203) of all sialolith cases. The submandibular gland was involved in 42% (13 of 31) of nonvisualization cases, as compared with 79% (160 of 203) of all sialolith cases. Nonvisualization occurred in 42% (18 of 43) of parotid cases versus 8% (13 of 160) of submandibular cases, a statistically significant difference (P < .001). Parotid stones located posterior to the plane of insertion of the posterolateral edge of the masseter were significantly more likely to experience nonvisualization (73%) than those along and anterior to the masseter (25% and 0%, respectively; P = .009). Conclusions Intraoperative nonvisualization of a sialolith is more likely to occur in the parotid gland. Proximal stone location may predict nonvisualization. These factors should be considered during treatment planning and counseling for patients with sialolithiasis.