Currently, the routine placement of abdominal drainage tubes after gastrectomy is still widely used worldwide for the early diagnosis and management of critical abdominal complications such as post-operative bleeding, anastomotic leakage, and intra-abdominal infections [5]. Successive studies, however, have shown no clear benefit from prophylactic abdominal drainage [10, 21]. In addition, the placement of drainage tubes increases the patient’s postoperative pain, prolongs the use of analgesics and leads to the occurrence of drainage-related complications [20]. As a result, some institutions no longer routinely perform PD after GC surgery. Nevertheless, as these studies are limited by relatively small sample sizes and underpowered statistics, the conclusions are unclear.

To our knowledge, this is the largest meta-analysis (21 studies including 5142 patients) to evaluate the role of PD in perioperative outcomes of GC surgery. In this study, we found that the routine use of PD after surgery did not reduce the incidence of abdominal complications such as anastomotic leakage and pancreatic leakage. In contrast, the overall complication rate was significantly higher in the PD group. In addition, the length of hospital stay and the time to soft diet were much longer in the PD group than in the ND group. Moreover, PD did not also show any benefit in reducing readmission, reoperation, or mortality in GC surgery.

Several previously published meta-analyses [10, 38,39,40] have demonstrated the potential benefits of PD avoidance in GC patients, which were largely in line with our results. However, those studies were only able to achieve reliable conclusions in a few variables due to a limited number of included studies. At variance, by integrating all applicable RCTs and observational studies, the present study highlighted a faster recovery in the ND group, except for a reduced morbidity and hospital stay, while the previous studies did not find this difference between the two groups. Moreover, benefiting from the increased sample size, nearly all the results in our study showed low heterogeneity and good agreement across the RCT subset and observational subset, further convincing us of the efficacy of ND in GC surgery.

In recent years, laparoscopic surgery has been widely performed in GC, but the role of PD in laparoscopic gastrectomy is still unclear. Therefore, we performed a subgroup analysis for laparoscopic resections. Based on the results from 567 patients who underwent laparoscopic gastrectomy, our finding of the benefit of ND in these patients remained unchanged. Besides, we found that in this subgroup, the incidence of anastomotic leakage (P = 0.11) and pancreatic leakage (P = 0.07) was slightly lower in the ND group, although there was no strong evidence at the pooled analyses that routine ND has an effect on reducing these adverse outcomes. With advances in surgical techniques and laparoscopic equipment, laparoscopic surgery has been shown to be less likely to result in serious postoperative complications in experienced centers, due to its minimally invasive nature [41,42,43]. Consequently, we believe that routinely using PD following laparoscopic gastrectomy is not necessary.

The avoidance of drainage tubes in simple and routine surgery is well understood, but its feasibility in the context of complex surgery is uncertain. Total gastrectomy is a highly complex and challenging surgical procedure in GC patients. Its operation time, intraoperative blood loss, and postoperative complications are much higher than other surgical methods [44, 45]. However, in our present analysis based on 1049 patients, we found that PD did not show any advantage over ND in patients undergoing total gastrectomy. Unexpectedly, several recent meta-analyses demonstrated that even pancreaticoduodenectomy and major liver resection can safely avoid abdominal drainage, which indicated that PD is not a substitute for a meticulous surgical procedure in complex operations [8, 46]. In view of this, avoiding routine drainage should also be recommended during total gastrectomy.

To further clarify the reliability and generalizability of our study, we also analyzed the effect of sample size (≥ 100 vs. < 100) and hospital nature (academic institution vs. non-academic institution) on the perioperative outcomes of PD in GC patients. As shown in Fig. S2–3, the pooled results of these subgroup analyses remained consistent with our previous meta-analyses. These results further convinced us that routine drainage after gastrectomy was not indispensable, even in non-academic hospitals where the surgeons’ expertise and the back system are relatively insufficient compared to academic hospitals.

Nevertheless, our findings are based on literature, some uncertainties exist in the evidence included in this meta-analysis. The lack of stratified information in the original literature prevented us from analyzing the applicability of ND in certain specific subgroups, such as patient demographics (age, BMI, co-morbidity, and history of abdominal surgery), surgical parameters (combined organ resection, extended lymphadenectomy, intra-operative blood loss and sterility of surgery) and oncological variables (neoadjuvant therapy and TNM stage). Therefore, the current evidence does not mean that abdominal drainage should be discontinued in all patients after GC surgery. What we can conclude is the avoidance of routine drainage of a prophylactic nature. Drainage is strongly recommended in some cases, such as abdominal contamination due to perforation and obvious iatrogenic organ injury [40, 47]. In addition, there is evidence demonstrating that PD may be useful in high-risk patients with long operative time or massive intraoperative bleeding [31, 34].

Recently, the first nomogram for predicting the risk of postoperative percutaneous drain placement has been constructed [31]. This prediction model encompassed sex, age, surgical approach, and operative time, which may enable the surgeons to identify high-risk patients, so that PD can be performed selectively. However, this model was derived from a retrospectively study without external validation. Future multicenter RCTs including risk-stratified randomization are urgently needed before final conclusions can be drawn.

The present study has some limitations that should be acknowledged. First, although 7 RCTs were included in our study, the quality of these RCTs was not high and did not also perform stratified analyses in specific populations, which had a certain impact on the reliability of the results of this study. Therefore, more well-designed RCTs with large sample sizes are expected to provide more credible evidence on this issue. Second, several included studies [24, 26, 33] were published over a large time frame, so improvements in gastric surgery and perioperative management during this time could potentially influence the results. Third, there was considerable heterogeneity between studies, including the type of drain used and the period of drain placement, which could also have an impact on the reliability of our results.