[Timing of resection in patients with colorectal carcinoma and synchronous liver metastases].

Timing of surgical therapy in patients with synchronous colorectal liver metastases is becoming more complex. The standard therapy for most of the patients remains resection of the colorectal cancer first followed 6 weeks later by liver resection. Simultaneous colon and liver resection is safe and advisable in cases of minor liver resections and right-sided colon tumours. Major liver resections in combination with resection of the colorectal cancer carry the risk of increased postoperative morbidity and mortality. They should be considered for selected patients only. A pre-requisite is, in addition, special expertise of the operating surgeon in colorectal as well as in hepatobiliary surgery. If the synchronous liver metastases are near to essential anatomic structures, the liver resection should be performed before the bowel resection. The same holds if the metastases are technically resectable, but the future liver remnant seems to be too small. Using well known techniques, the future liver remnant should be increased and the liver metastases resected before treatment of the colonic primary tumour. The risk for local complications is very low when leaving the colorectal tumour in situ during treatment of liver metastases. When synchronous liver metastases are technically not resectable or carry a high risk of an R1 resection, patients should be treated first with systemic neo-adjuvant chemotherapy. If sufficient down-sizing of the metastases can be achieved, liver resection should be performed before bowel resection. A close cooperation between the oncologist and the hepatobiliary surgeon is most important, since the window for curative surgery is rather limited in these patients. In patients with resectable synchronous liver metastases, the advantage of a neoadjuvant chemotherapy has not been proven yet.