Discussion
This is the first large study to evaluate the feasibility of a comprehensive ERAS program in gastric surgery. In our study, the overall incidence of morbidity (i.e., ≥grade 2 complications) was 10.8%, and the incidence of clinically significant events (≥grade 3 complications) was only 3.9%. These results obtained with our ERAS program are good as compared with complication rates of conventional perioperative care group in our previous report (12.0%) as well as other reported complication rates without ERAS program (10.5–46.0%). Although T1 tumors and D1 dissection were dominant in our study, the morbidity rate in the D2 group (18.1%) was comparable to that in a large randomized controlled trial performed in Japan (JOCG9501 study, 20.9%).
Among the many elements of ERAS programs, one of the utmost concerns for surgeons is that early postoperative feeding can induce postoperative ileus or anastomosis leakage. Because of these concerns, oral intake of food was previously not allowed for several days after gastrectomy in Japan. In some European countries, food is also withheld for several postoperative days, but this practice is not supported by adequate evidence. In fact, in our study the incidences of postoperative ileus and anastomotic leakage were very low (1.0% and 1.5%, respectively), as compared with previous studies (0–12.5% and 0–4.2%, respectively). The incidences of those in conventional prieoperative care of our hospital (0% and 2%, respectively) were similar with these results. Furthermore, meal step-up did not have to be delayed in nearly all patients (95.1%), and this is also similar with previous reported our internal control (96.0%). Several studies have also demonstrated that early oral feeding is feasible and beneficial in gastric surgery, but this point remains controversial. Heslin et al. reported that early enteral feeding was not beneficial after surgery for upper gastrointestinal malignancies. On the other hand, Lewis et al. found in their meta-analysis that keeping patients 'nil by mouth' is without benefit; in contrast, early enteral feeding was suggested to reduce mortality. There were six complications that need reoperation in current study. Among those, possibility of relation between the leakage of the gastroduodenal anastomosis and ERAS program could not be denied. But others seem to be unlikely. Our results and the findings of previous studies suggest that early oral or enteral feeding is at least feasible and does not increase the risk of postoperative ileus or anastomotic leakage.
Our study had several limitations. 1) It was conducted retrospectively in a single hospital, and the analyses and endpoints were not preplanned. 2) Most patients had good performance status. Patients with poor performance status (e.g. Eastern cooperative oncology group performance status ≥3, severe dementia, and swallowing difficulty) could not be treated in our hospital, because we specialize in cancer treatment. These could be selection bias. 3) More than half of the patients had T1 disease and underwent limited lymph node dissection (D1+), whichmight account for the good results of our study. In particular, D2 or more radical lymph node dissection has been repeatedly reported to increase the risk of surgery-related complications. Consistent with the previous findings, the incidence of complications was higher after D2 dissection than after D1 dissection in our study. Finally, 4) our ERAS program did not include fluid management, which is one of the key elements of ERAS programs. There was not robust evidence of perioperative fluid management in gastric surgery at the time we introduced ERAS.