Preoperative inspiratory muscle training preserved diaphragmatic excursion after esophagectomy: a randomized-controlled trial

Abstract Background Preoperative inspiratory muscle training (IMT) enhances diaphragmatic excursion (DE) in patients with esophageal cancer; however, the postoperative effects of IMT on DE have not yet been evaluated. This study aimed to investigate the effect of preoperative IMT on perioperative diaphragmatic function as measured by DE, inspiratory muscle strength, lung function, and exercise tolerance. Methods This was a parallel, randomized-controlled trial. Patients with thoracic or abdominal esophageal cancer scheduled for esophagectomy were randomized into either the incentive spirometry (IS) or IMT group. Each intervention was performed during preoperative neoadjuvant chemotherapy (NAC). The primary outcome was the DE, and the secondary outcomes were maximal inspiratory pressure (MIP), lung function, and exercise tolerance, which were measured before and 1–3 months after esophagectomy. Results Thirty-two patients were included in the analysis. The DE in the IMT group (n = 15) increased from baseline to pre-operation, and the rate of change was significantly greater than that in the IS group (n = 17). Although the DE and MIP decreased in both groups after esophagectomy, the decline in the DE after esophagectomy was significantly lower in the IMT group than that in the IS group (p < 0.05). Furthermore, significant differences in DE persisted at least until 3 months post-esophagectomy, whereas MIP did not differ significantly at any time point. Pulmonary function and exercise tolerance were not significantly different between the two groups. Conclusions The IMT before esophagectomy enhanced diaphragmatic function, which was preserved for more than 3 months after esophagectomy.