It has been more than 10 years since the timing of surgical drain removal emerged as a topic of active debate, and the current ERAS recommendations include the removal of drains on POD3 in patients with DFA levels of < 5000 IU/L on POD17. Several previous studies have demonstrated the feasibility and benefits of early drain removal after PD in low-risk patients9,11,13, and we are already well aware of its advantages. However, a former national survey investigating the application of individual items in the ERAS guidelines showed that many surgeons adopt only some of those items, and still rely on inconsistent experience-based management for other items including drain removal12. A recent study of the Japanese Society of Surgical Metabolism and Nutrition conducted by Kaibori et al.14 showed encouraging results, that their promotion project improved the rate of implementation of the ERAS protocol. However, the report did not indicate the degree of improvement in the detailed items. Therefore, in the present study, we aimed to record the results during the past two transitional period years when the early drain removal protocol was implemented in our institute.
In our database, there were only 91 (20.2%) patients in the cohort whose drains were removed within POD3. Even though the early removal protocol has been implemented in the institute since 2018, not all surgeons immediately followed the guidelines for fear of adverse events such as failing to notice anastomotic leakage. In accordance with several studies investigating the adherence rates to the ERAS items12,15,16, the adherence to postoperative items including drain management tended to be lower than that to the preoperative items. This would be explained by its relevance to complications in addition to the drastic difference from traditional management. In this regard, we investigated the rate of additional percutaneous or endoscopic drainage tube insertion for intra-abdominal fluid collection or POPFs after drain removal and there was no statistical difference between the early and late removal groups. This suggests that early drain removal would not increase adverse events requiring additional intervention. Also, it should be noted that drains can help detect intra-abdominal complications, but not fundamentally prevent them. On that basis, there is a need to consider a more extensive implementation of the early drain removal protocol.
With regard to CR-POPFs, many studies have analyzed the risk factors and proposes risk scoring systems6,17−21. In addition, there have been attempts to set criteria for the early removal of drains10,22. Among a number of variables, the most emphasized was the POD1 DFA level. To identify other factors independent of POD1 DFA levels, we performed multivariable risk factor analysis in patients with POD1 DFA levels of less than 5000 IU, and the tumor location was found to be an independent factor. However, the timing of drain removal did not increase the risk of CR-POPFs. This implies that drains can be safely removed earlier in patients with POD1 DFA levels of < 5000 IU, without increasing the risk of intra-abdominal complications including POPFs, while reducing the length of hospital stay and enhancing early recovery. Meanwhile, in the analysis of all 450 patients including those with POD1 DFA levels of ≥ 5000 IU, early drain removal had the advantages of lower complication rates including POPFs and shorter hospital stays over late drain removal. Altogether, further studies on the risk factors for POPFs or postoperative intra-abdominal complications other than DFA levels, are necessary to select the candidates for early and safe removal of surgical drains.
There were several limitations to this study. Above all, this was a single-center retrospective study, which is prone to selection bias. Information bias is also of concern because the data on postoperative events such as complications were collected from previously archived medical records. Secondly, regardless of the clinical pathway, which was modified in 2018 according to the ERAS guidelines, each surgeon actually applied the new drain protocol at different times. During the transition period, not all surgeons had drains removed within POD3 in patients with POD1 DFA levels of less than 5000 IU and the definition of early or late drain removal was unclear. The timing of follow-up imaging and the date of discharge also varied. Therefore, the influence of surgeon-specific factors on operative and post-operative outcomes cannot be excluded. Nevertheless, based on the results of our study, which included a relatively large number of patients undergoing PD, all surgeons in our institute are now considering the practical implementation of early drain removal.
In conclusion, we investigated the realistic advantages of early drain removal after PD and found that the evidence-based protocol for early drain removal did not increase postoperative morbidity and may reduce the length of hospital stay.