General descriptive analysis
Patients demographics and clinical information of the responders and non-responders are summarized in Table 2 and 3.
Lithiasis was found in 50.7% of the total population and most frequently seen in the submandibular gland (76.8%). If lithiasis was found, retrieval of the stone, either by sialendoscopy alone (n=45) or by combined approach (n=76), was successful in 90.9% of the total population. When comparing success rates between on the one hand the responder (87.3%) and non-responder group (94.8%; p=0.150) and on the other hand the parotid (83.3%) and submandibular group (92.8%; p=0.149) there were no significant differences (Chi-square test). In 10 patients no stone was found during the procedure, despite preoperative diagnosis of lithiasis. The chance of success of stone retrieval depended on the L classification, as summarized in Table 4. As expected, good results were seen in the L1 and L2a classification groups, but also the L3a classification group showed a high percentage of successful retrieval. All but two retrieval failures were with fixed stones (L2 or greater; n= 81).
Stenosis was the most frequent pathology in the parotid gland (57%). Sialendoscopy was most frequently performed within a combined approach setting for lithiasis (55.1%) than for addressing other pathologies (only 15.7% of non-lithiasis parotid cases needed a combined approach; p<0.01, Chi-square test).
Complications occurred in 11 out of 272 sialendoscopies. Seven patients had iatrogenic perforations, 2 patients a temporary lingual nerve paresthesia following combined submandibular approach and 2 patients had a pronounced but temporary swelling of the floor of the mouth which did not necessitate additional treatment.