Review of the use of prophylactic drain tubes post‐robotic radical prostatectomy: Dogma or decent practice?

Abstract Objective To assess the necessity of routine prophylactic drain tube use following robot‐assisted radical prostatectomy (RARP). Method We performed a literature review using the Medline, Scopus, and Web of Science databases with no restriction of language from January 1900 to January 2020. The following terms we used in the literature search: prostatectomy, radical prostatectomy, robot assisted, drainage, and drain tube. Results We identified six studies that examined the use of routine prophylactic drain tubes following RARP. One of these studies was a randomized study that included 189 patients, with 97 in the pelvic drain (PD) arm and 92 in the no pelvic drain (ND) arm. This non‐inferiority showed an early (90‐day) complication rate of 17.4% in the ND arm versus 26.8% in the PD arm (P < .001). Another non‐inferiority randomized control trial (RCT) showed a complication rate of 28.9% in the PD group versus 20.4% in the ND group (P = .254). Similarly, the other studies found no benefit of routine use of prophylactic drain tube after RARP. Conclusion Drain tubes play a role during robotic‐assisted radical prostatectomy, however, following a review of the current available literature, they can be safely omitted and we suggest that clinicians may be selective in their use.

supporting their use, particularly when employed for purposes of prophylactic drainage. Similarly, there are recognized risks associated with insertion of pelvic drains including pain, infection, and prolonged hospital stay. 4 Robotic-assisted radical prostatectomy (RARP) is an internationally accepted standard approach for the management of localized prostate cancer. 5 With the rapid uptake of RARP internationally, the question as to the necessity for routine insertion of surgical drains during this particular modality of procedure remains unanswered. 5 The rationale for insertion of a pelvic, surgical drain following RARP is multifaceted, with many indications established historically not necessarily retaining relevance within the context of robotic surgery. For example, the running anastomosis made possible with the robotic approach is more watertight than the interrupted suture technique utilized with an open or laparoscopic prostatectomy, making anastomotic urine leak, and subsequent urinoma less common. 6 The primary purpose of the following review was to examine the current body of literature pertaining to the insertion of routine pelvic surgical drains during RARP. We aimed to determine whether routine insertion of pelvic surgical drains is necessary following RARP.

| ME THOD
A literature review was performed using Medline, Scopus, and Web of Science to identify relevant articles published up until January 2020. The following terms were used to identify relevant articles "prostatectomy," "radical prostatectomy," "robot assisted," "drainage," and "drain tube." There were no restrictions placed on language, year, or study design. About 126 articles were imported into Endnote x9 where duplicates, abstracts, and irrelevant titles were filtered out. For analysis, we included full text publications that compared outcomes of RARP with versus without pelvic drain tube.

| RE SULTS
We identified six studies that examined the use of prophylactic drain tubes following RARP with combined total of 8338 cases analyzed.
One randomized study by Chenam et al 5    Drainage postgastrectomy has also been analyzed in a metaanalysis which included four randomized control trials (438 patients). 16 Similarly, the authors did not find any convincing evidence to support the routine use of prophylactic drainage after gastrectomy. For pancreatic surgery, a meta-analysis comprised of five randomized control trials and eight non-randomized studies failed to reach a clear conclusion on whether there was a benefit of routine use of prophylactic drainage. 17 In Urological surgery, the role for the routine use of prophylactic drainage is also being explored. A randomized study comprised of 106 patients undergoing open nephrectomy found the presence of a surgical drain tube to not affect the rate of complications (P = .249). 18 Despite the randomized nature of the study, we should however acknowledge that these results were based on a small sample size. In a series of 208 patients undergoing laparoscopic radical prostatectomy with a running urethrovesical anastomosis (RUVA), the authors concluded that routine use a prophylactic drain was not necessary. 19 The need for a routine prophylactic drain was also shown to be unnecessary in a series of 552 patients undergoing RRP given there were no concerns with the anastomosis. 20 Similarly, in their series of 116 patients, Savoie et al concluded that the use of routine prophylactic drain could be avoided following RRP. 21 With regards to the routine use of prophylactic drains following RARP, the results presented in this analysis indicate that we can omit drains in select cases. However, only two of the studies were randomized, and these studies also had limitations. One study did not accrue as initially intended and as such the final sample study in this analysis is small. 5 The other RCT it was a single center study with small numbers and only two surgeons. 7 This raises questions about applicability of the findings to the general population. The other studies are largely retrospective or single surgeon series which may, therefore, have inherent bias. [8][9][10][11] Despite the noted study limitations, these results still indicate a role of selective use of surgical drain tubes based on factors including specific patient characteristics, concerns with the anastomosis or issues with hemostasis rather than adopting a blanket rule for all patients where the default action is to place a drain tube. The concept of omitting a drain tube would also be in-line with enhanced recovery after surgery (ERAS) protocols and the growing notion of same-day discharge RARP which is getting explored more and more in some parts of the world. 22,23 A potential concern following prostatectomy is the development of a symptomatic lymphocoele. However, after RARP with lymph node dissection, symptomatic lymphocoeles are particularly rare. Keskin et al reported an incidence of symptomatic lymphocoeles of 2.5% in their series of 521 patients who underwent RARP with Eplnd. 24 The rate of symptomatic lymphocoele after RARP with PLND is much lower compared to the reported incidence following open PLND. 25 Reasons for this are debatable with some studies suggesting the rate of lymphocoele formation as being associated with the extent of lymph node dissection but similarly, certain studies have also found no association between lymphocoele development and extent of lymph node dissection. [26][27][28] Prophylactic drain tube placement may not prevent lymphocoele formation as indicated by the results presented in this review. As more studies explore this issue, a drain tube score could potentially be established based on more reliable evidence to help guide clinicians in assessing the need for a drain on an individualized, case-specific basis, and determined by specific patient, disease, and surgical factors.

| CON CLUS ION
Drain tubes play a role during robotic-assisted radical prostatectomy, however, following a review of the current available literature, they can be safely omitted, and thus, we suggest that clinicians should be selective when it come to their use rather than preemptive.