Introduction : Two stage hepatectomy has been widely performed for last decades as the paradigm of definition of resectability has shifted. There are many studies that advocate the efficacy of two stage hepatectomy , but rare reports that pactically compare the oncologic outcome between surgical group and non-surgical group.

Methods : From January 2010 to November 2018, 51 patients were planned for 2 stage hepatectomy and 43 patients
were enrolled for this study. One of three modalities were used for 2 stage hepatectomy (Portal vein embolization(PVE), Selective ligation of Portal vein(PVL), ALPPS). Control group was selected according to the criteria below; Before 2010, when two stage hepatectomy has started in our institution, patients who were received R0 resection of colon cancer diagnosed colorectal cancer with bilobar multiple liver metastases and without other organ metastasis.

Results : PVE, Selective ligation of PV, ALPPS were performed in 12 (27.9%), 17(39.5%), 13 (30.2%) cases. Postoperative motility occurred in 2 patients(4.7%). Recurrence was observed in 29 patients (67.4%) and among them, 19 patients(44.2%) showed early recurrence within 6 months. 7 patients(16.3%) were alive without disease, and 15 patients(34.9%) were alive with disease. In terms of overall survival, 2 stage hepatectomy group showed statistically significant prolonged survival (p<0.001) with 36% of 5 years survival.

Conclusions : Two stage hepatectomy can give better oncologic outcome compared to non-surgically treated group in patients with colorectal bilobar multiple liver metastasis. Therefore aggressive surgery is worthwhile and challengeable despite of technical difficulty.