The FEES-registry assessed the safety and clinical impact of FEES in a prospective multicenter design across different levels of care facilities in a heterogeneous patient cohort. The study’s first main finding was that the procedure was safe and well tolerated, and complications, in particular laryngospasm, epistaxis and hypotensive episodes were very rare and always self-limited, thereby corroborating reports from the literature [
32‐
36]. Secondly, this study showed that the incidence of procedure-related side-effects was not related to the endoscopist’s experience. Therefore, FEES seems to be safe even when performed by professionals with limited prior training. This result supports recently published formalized training curricula for FEES that suggest that after taking part in a dedicated workshop, conducting 60 supervised examinations and passing a practical test physicians and SLTs can safely perform this procedure [
25‐
27]. Third, this trial showed that FEES was associated with discernible but clinically insignificant alterations of cardiovascular parameters. Interestingly, and in line with a smaller previous trial exclusively focusing on acute stroke patients [
36], the recorded mild increases of heart rate and systolic blood pressure were clearly less pronounced than encountered during placement of nasogastric tubes in acute stroke patients with dysphagia [
37]. In the latter scenario a mean increase of systolic blood pressure of 35 mmHg (as opposed to 3.5 mmHg in the present trial) and a mean increase of heart rate of 23 bpm (as opposed to 3.2 bpm in the present trial) were noted. Therefore, it may be concluded that the FEES procedure, even if examination times may be longer, is not as unpleasant as any procedure involving blind manipulation within the nostrils and the pharynx such as placing nasogastric tubes or nasotracheal suctioning. Fourth, this study showed that a simple FEES-based algorithm grading dysphagia severity according to efficiency and safety of swallowing with regards to different consistencies correlates well with the less swallowing specific FOIS score. In the past, this algorithm was used in patients with movement disorders [
16,
31]. However, since the present multicenter trial has demonstrated that the algorithm (i) is readily applicable in different diagnostic groups and (ii) is able to grade dysphagia in a clinically meaningful way, it may be assumed that this FEES-score could be helpful in everyday patients’ care and might be useful as an endpoint in clinical studies devoted to the topic of neurogenic dysphagia [
38]. Finally, the present study also collected data with regards to the impact of FEES on dysphagia management. In more than 50% of patients FEES led to changes in the feeding strategy. Furthermore, in more than 25% of the subgroup of 447 tracheotomized patients, decannulation was deemed safe based on FEES-findings. These results corroborate existing literature, which usually focused on specific patient cohorts. Thus, in a recent study recruiting stroke patients and adopting a pre-post-design, Bax and co-workers showed that providing FEES-service on a stroke unit reduced the incidence of post-stroke pneumonia and increased the proportion of patients leaving hospital on a regular diet [
39]. Hafner et al. reported clinical consequences of using FEES in a critical care setting in recently extubated patients [
23]. Based on FEES prolonged non-oral feeding was required in 49.7% of patients, in 6.3% a tracheostomy was performed, an oral diet was started in 30.7% and tracheostomies were closed in 22.9%. Evaluating swallowing function in tracheostomized neurointensive care patients with a FEES-based decannulation algorithm, Warnecke et al. demonstrated that safe decannulation was possible in more than 50% of patients, whereas only about 30% of them would have been decannulated based on clinical swallowing evaluation alone [
40]. Taken together, these studies provide first evidence that implementation of a FEES-service in different clinical settings may improve dysphagia care.
The strengths of this prospective observational study are its multicentre design, the inclusion of a heterogeneous patient cohort and the specific documentation of different features of the examination setting and of the respective results. However, some limitations are apparent. First, trial sites were chosen among those hospitals actively supporting the German FEES education initiative. Therefore, it is conceivable that sites with a more advanced level of proficiency were chosen against less experienced centres, which may have introduced a bias into the findings. Second, the study did not include documentation of potentially eligible patients that for various reasons were not recruited in the end. Hence, a selection bias cannot fully be ruled out. Third, probably reflecting the usual distributions of different disease categories in a given patient collective, stroke was by far the most common disease, whereas other disorders were significantly rarer. Thus, the generalizability of the study’s conclusions may be limited to a certain extent. Fourth, the documentation of how FEES was performed in detail was for reasons of practicability limited. Therefore, for example, it was not recorded whether topical anesthesia had been used, a factor that may well have been related to patients’ comfort [
41] Fifth, there was no central reading of FEES findings and, sixth, for some study items the proportion of missing data was rather high. Both of these aspects may have impacted the scientific validity of the study’s results. Finally, while this study showed that FEES was safe even in the hands of less experienced endoscopists, the quality of the examinations and the derived conclusions were not scrutinized and evaluated.
In conclusion, this study confirmed that FEES, even when performed by less experienced clinicians, is a safe procedure with only moderate associated alterations of cardiovascular parameters. FEES had a significant impact on dysphagia management and by adopting a simple FEES-based dysphagia score, FEES showed to provide a clinically meaningful assessment of overall dysphagia severity.