Maarten van Egmond

55 The pre- and postoperative course of functional status 3 mellitus type 2 (DM II) were present (COPD 7.1% vs. 19.4%, DM II 6.5% vs. 43.9% in the CABG group). Functional status is highly dependent on cardiorespiratory components. Therefore, it could be stated that the initial preoperative functional status of our study cohort was much higher compared to other surgical populations. 9 Tew et al. 34 stated in their clinical guidelines on preoperative training in major non-cardiac surgery that every patient with an indication for surgery should be provided with preoperative exercise training to increase physiological and functional status. An increased physiological and functional status helps patients to better withstand the negative effects of surgery, such as postoperative pulmonary complications. 7 Based on the results of our study, however, it might be questioned whether preoperative exercise training to increase preoperative physiological and functional status is beneficial for all patients with an indication for esophagectomy, because preoperative functional status was on average higher than normative values and did not change between 3 months preoperatively and 1 day preoperatively. It could be hypothesized that little improvement in physiological and functional status is to be expected with preoperative training if functional status is already high, and therefore, these patients should not be provided with prehabilitation. Moreover, there seems to be no relationship between preoperative functional status and postoperative recovery in our study cohort. This is in line with a study by Valkenet et al. 35 who did not find any significant improvements in aerobic capacity, HGS, knee extension strength and elbow flexion strength after a preoperative exercise program in a comparable group of cancer patients scheduled for elective gastrointestinal surgery. The authors suggested that the results could be due to the relatively short training period, but the high fitness levels of these patients could also be an explanation for the lack of effectiveness. Dettling et al. 36 demonstrated in a comparable esophageal cancer population that preoperative inspiratory muscle training did not lead to an expected postoperative reduction of pneumonia and concluded that these patients seemed to benefit less from inspiratory muscle training than other surgical populations. Moreover, it could be questioned whether esophageal surgery-related complications, such as anastomotic leakage, could be prevented with increased preoperative functional status. Although prehabilitation is also aimed at improving postoperative recovery after postoperative complications, this study surprisingly showed no difference in recovery between patients with and without postoperative complications. This raises the question of whether and when postoperative exercise training should be indicated. A review by Hoogeboom et al. 8 stated that training should start as early as 4 hours after surgery, and the exercise therapy should be tailored to the individual needs of the patient to improve postoperative recovery. To identify these needs and to determine if physiotherapy is indicated, it is essential to assess functional status.