Current status of preoperative biliary drainage.

Preoperative biliary drainage (PBD) has been thought to be preferable regardless of the site of biliary strictures, e.g., distal or proximal strictures because PBD by endoscopy or interventional radiology decreases postoperative mortality and morbidity rates. However, recently, several studies have revealed that PBD strategy showed an increased mortality rate or a high frequency of surgical site infection. Herein, we reviewed reports in the literature regarding the current status of PBD and investigated the effects of PBD on patients with distal and proximal biliary obstructions due to potentially resectable pancreatobiliary cancers. Our summary demonstrated that there is as yet no optimal PBD method regardless of the distal and proximal biliary strictures because of the small sample size and the lack of better control groups in previous studies. Thus, prospective randomized studies with a large sample size are needed to establish the optimal mode of PBD and to evaluate the potential benefits of PBD in patients with both distal and proximal biliary obstructions.