Tongue Pressure Post-Oesophagectomy: Nature, Trajectory, and Association with Swallow Safety

Abstract

Purpose: Oesophageal cancer is a leading cause of cancer worldwide and despite advancements in treatment, it is a leading cause of cancer mortality (Kamangar et al., 2020; Sung et al., 2021). An oesophagectomy is a complicated procedure and respiratory complications, including pneumonia, are a leading cause of postoperative death (Sung et al., 2021). Aspiration, which can be attributed to dysphagia, is a common cause of postoperative pneumonia (Duff et al., 2022; Pikus et al., 2003). Dysphagia is the most common presenting symptom in oesophageal cancer (Gillman et al., 2022; Kato et al., 2007; Martin et al., 2001). The tongue plays a crucial role in the safe formation and propulsion of the bolus during swallowing (Checklin & Pizzari, 2018; Logemann, 1988) and tongue pressure has been associated with impaired swallow safety in other clinical populations (Borges et al., 2020; Lee & Choi, 2020; Perry et al., 2021). This study aims to; (i) investigate tongue pressures immediately post-oesophagectomy and to compare findings to published normative data, (ii) identify differences in tongue pressure measures across parameters including sex, age, length of ICU stay, postoperative day, and surgery type, (iii) determine the association between tongue pressure and aspiration as identified during videofluoroscopy, and (iv) examine the trajectory of tongue pressure over time based on a longitudinal analysis at one month post- surgery. Method: A cross-sectional and longitudinal research design were chosen to address the aims of this study. Adults with a diagnosis of oesophageal cancer who were due to have an oesophagectomy were recruited from the upper gastrointestinal clinic at the National Oesophageal Centre, St. James’ Hospital, Dublin. Posterior tongue strength (MIPpost), anterior tongue strength (MIPant), tongue endurance, and swallow safety were assessed consecutively at day four or five postoperatively. Repeat tongue pressure measures were obtained at one month post discharge. Descriptive and inferential statistics were used to analyse data. Results: Eleven participants (four females; seven males; mean age 65 years; age range 46-82 years) were recruited over a four month period. At postoperative day four or five, mean MIPpost was 41.43 kPa±10.44 kPa (range 25.1 kPa-56.2 kPa) and mean MIPant was 44.03 kPa±9.68 kPa (range 28 kPa-57 kPa). Mean tongue endurance was 8.59 sec±3.8 sec (range 2.8 sec-15.8 sec). Mean tongue endurance in people with oesophageal cancer who were four or five days post-oesophagectomy (8.59 s, CI=6.03-11.14) was significantly lower than in comparison to the published normative data (22.39 s; CI=20.78-24.12), t(429)=2.624,p=0.009, two-tailed. While not significantly different, there was nearly a seven second difference in mean tongue endurance measures taken at one month following discharge in comparison to published normative data, t(428)=1.358, p=(0.175), two-tailed. Overall, tongue pressure measures were not associated with aspiration, and a negative association was found for just two conditions; (i) MIPant and L0 sequential sips, r(9)=-.205, p=.544, and (ii) MIPpost and L0 sequential sips, r(9)=-.020, p=.953. Descriptive statistics showed MIPpost, MIPant and tongue endurance improved spontaneously from four or five days post-oesophagectomy, to one month following discharge. Conclusion: The difference in mean tongue endurance in people with oesophageal cancer immediately post- oesophagectomy in comparison to published normative data may inform the management of this population as well as guide future management in this area. As tongue pressure measures were shown to spontaneously improve over a one month period, this may also call into question the need for lingual focused rehabilitation. The findings from this study also suggest that as tongue pressure measures were not associated with swallow safety, pharyngeal based rehabilitation may be more appropriate for this population and this needs further investigation