Preoperative biliary drainage (PBD) has been used in patients with obstructive jaundice and it is believed to improve the patient outcomes by possibly improving liver function. It is especially useful in decompressing an infected biliary system with cholangitis and also helps in delineating the anatomy before surgery. There are however, some meta-analyses that suggest higher peri-operative complications in patients with PBD especially for the endoscopic route. On the other hand, other meta-analyses and reviews have also been published suggestive contrasting outcomes. These contrasting findings suggest that PBD should not be used without discretion. Or perhaps the key lies in the duration of drainage. In addition, the mode of PBD may have long-term oncologic significance with postulation that percutaneous route predisposes to track seeding of tumour.
Portal vein embolization(PVE) is an excellent strategy to induce pre-surgery hypertrophy of the future liver remnant (FLR). It is especially useful in bilateral colorectal liver metastases where it is combined with 2 stage hepatectomy (conventional or with ALPPS) to improve resection rates. In diseased liver, it also helps surgeons to gauge safety of resection by the degree of hypertrophy. However, there is increasing evidence to suggest that PVE may also induce liver tumour growth and even promote metastases suggesting that PVE should only be applied for patients who can benefit from a likely hypertrophy of the FLR. There is also some suggestion on the role of neoadjuvant chemotherapy in selecting such patients.