162 CHAPTER 7 Study limitations The first and most important limitation of this study is the design. The variation in follow-up time ranged from one to 12 years. A greater follow-up time is likely to have an influence on the long-term measurements. However, we did not find a correlation in the difference between long-term and 32 weeks VAS and the followup time. Future research on the extent of the decrease in 2-DL effect after specific amounts of time, e.g. 1 year, 5 years and 12 years, would give more insight into this phenomenon. Another limitation is the amount of missing data, which forced us to exclude 12 patients from the VAS and DF analysis and 11 from the DS analysis. Another limitation is that we only used subjective outcomes. The Drooling Quotient (DQ), used in previous studies, is not sensitive to caregivers’ subjectivity because it is scored by a trained speech language therapist and could therefore be a useful instrument for future research.11,13 Conclusion 2-DL is a technically straightforward, quick option with generally mild complications and limited perioperative morbidity. There is, however, a not yet fully understood decrease in treatment effect over the medium to long term. Despite this, the majority of patients would recommend 2-DL to peers. Given the benefits, 2-DL might be the treatment of choice in specific cases of persistent excessive drooling refractory to conservative treatment. Future research should evaluate strategies to prevent alternative salivary pathways after 2-DL. Furthermore, future research should compare 2-DL with SMGE and SMDR in the long-term. Acknowledgements We want to thank Corinne Delsing, Corrie E. Erasmus, Marloes Lagarde, and Sandra de Groot for their contribution in patient care.
RkJQdWJsaXNoZXIy MjY0ODMw