Okayama University discovers gum chewing is effective after esophageal cancer surgery for prevention of aspiration and fever

Esophageal cancer surgery is one of the most invasive gastrointestinal surgeries and carries a high risk of postoperative complications such as aspiration. A research group led by Assistant Professor Reiko Yamanaka of the Department of Preventive Dentistry, Division of Dentistry at Okayama University Hospital, and Professor Daisuke Ekuni of the Department of Preventive Dentistry at Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences; together with a group led by Lecturer Kazuhiro Noma of the Department of Gastroenterological Surgery at Okayama University Hospital; and a research group including Lecturer Kazuyoshi Shimizu of the Intensive Care Unit, and Assistant Professor Toshiharu Mitsuhashi of the Center for Innovative Clinical Medicine at Okayama University Hospital have confirmed for the first time in the world that perioperative gum-chewing training is effective for prevention of oral hypofunction and postoperative complications such as fever after esophageal cancer surgery. The results were published in Scientific Reports.

The research group compared patients who received gum-chewing training (gum group) for approximately two weeks each before and after esophageal cancer surgery (three sessions a day, for approximately five minutes per session) with patients who did not receive gum-chewing training (control group). The comparison was made in terms of the proportion of patients with decreased tongue pressure as the tough pressure is a measure of swallowing function. The results exhibited a significant decrease in the proportion from 76% in the control group to 44% in the gum group.

In the gum group, not only postoperative tongue pressure reduction was prevented, but also tongue pressure was improved even in patients with surgical damage. Moreover, the duration of postoperative fever was also significantly shortened. The gum group showed significantly better swallowing function than the control group and tended to have fewer cases of postoperative aspiration and pneumonia, although the differences were not significant. Meanwhile, no complications or disadvantages attributable to gum chewing were observed.

These findings suggest that gum-chewing training before and after esophageal cancer surgery may safely prevent postoperative deterioration of swallowing function and may even improve swallowing function to prevent postoperative aspiration, subsequent fever, and pneumonia. Tongue stretching exercises using chewing gum are also recommended.

Yamanaka said, "We were able to complete this study safely with the cooperation of specialists in various fields, including dentistry, surgery, anesthesiology, statistics, and nursing, not to mention the patients. This study was conducted in the midst of the COVID-19 pandemic, during which many patients underwent surgery for aggravation of esophageal cancer caused by refraining from screening and hospital visits. The fact that safety and efficacy were confirmed under such a circumstance has made the study all the more significant. "

"In this study, we asked the patients not only to chew gum but also to undergo professional oral hygiene procedures and tongue stretching exercises using gum. Having tongue stretching exercises with a clean mouth capable of chewing is considered the key to achieving a higher level of effectiveness. A pleasant taste, long taste retention, and good chewing texture of the gum used in the study may have helped the patients to continue the training program in an enjoyable manner. The intensive care unit nurses told me that having something tasty in the mouth, even for a short time during the postoperative fasting period, could have been psychologically good for patients who had to refrain from oral ingestion of anything. Some patients commented that they were anxious about the surgery, but their anxiety was eased while chewing gum."

Journal Information
Publication: Scientific Reports
Title: Perioperative gum-chewing training prevents a decrease in tongue pressure after esophagectomy in thoracic esophageal cancer patients: a nonrandomized trial
DOI: 10.1038/s41598-024-74090-4