The Problem of Appetite Loss After Major Abdominal Surgery: A Systematic Review

Abstract

Objective: To systematically review the problem of appetite loss after major abdominal surgery.

Summary of background data: Appetite loss is a common problem after major abdominal surgery. Understanding of etiology and treatment options is limited.

Methods: We searched Medline, Cochrane Central Register of Controlled Trials, and Web of Science for studies describing postoperative appetite loss. Data were extracted to clarify definition, etiology, measurement, surgical influence, pharmacological, and nonpharmacological treatment. PROSPERO registration ID: CRD42021224489.

Results: Out of 6144 articles, we included 165 studies, 121 of which were also analyzed quantitatively. A total of 19.8% were randomized, controlled trials (n = 24) and 80.2% were nonrandomized studies (n = 97). The studies included 20,506 patients undergoing the following surgeries: esophageal (n = 33 studies), gastric (n = 48), small bowel (n = 6), colon (n = 27), rectal (n = 20), hepatobiliary (n = 6), and pancreatic (n = 13). Appetite was mostly measured with the Quality of Life Questionnaire of the European Organization for Research and Treatment of Cancer (EORTC QLQ C30, n = 54). In a meta-analysis of 4 randomized controlled trials gum chewing reduced time to first hunger by 21.2 hours among patients who had bowel surgery. Other reported treatment options with positive effects on appetite but lower levels of evidence include, among others, intravenous ghrelin administration, the oral Japanese herbal medicine Rikkunshito, oral mosapride citrate, multidisciplin-ary-counseling, and watching cooking shows. No studies investigated the effect of well-known appetite stimulants such as cannabinoids, steroids, or megestrol acetate on surgical patients.

Conclusions: Appetite loss after major abdominal surgery is common and associated with increased morbidity and reduced quality of life. Recent studies demonstrate the influence of reduced gastric volume and ghrelin secretion, and increased satiety hormone secretion. There are various treatment options available including level IA evidence for postoperative gum chewing. In the future, surgical trials should include the assessment of appetite loss as a relevant outcome measure.

Figure 1

Graphical summary of results.

Figure 2

PRISMA flow chart. PRISMA indicates preferred reporting items for systematic reviews and meta-analysis.

Figure 3

Number of studies plotted by type of operation.

Figure 4

Evidence mapping for appetite loss after major abdominal surgery. Studies are mapped by time between operation and appetite measurement (x-axis with log 10 scale) and by type of operation (y-axis). Within the bubble plots, the number of patients with appetite measured is expressed by bubble size and randomization is expressed by a color code. Preoperative appetite measurement was performed in 45 studies (not displayed). If appetite was measured postoperatively more than once in a study or for different surgery types, all measurements are depicted separately, with the patient number for the whole study. If an interval instead of a fixed value of days since operation was stated in the study, the mean is displayed. If mean was not stated, median is displayed. If only a timeframe with 1 boundary (eg, more than 6 years) was stated, this boundary (eg, 6 years) is displayed. If neither was presented, the study is not displayed.

Figure 5

Meta-analysis for time to first hunger with gum chewing as an intervention. Forest plot (top) and risk of bias assessment (bottom).