Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) for cholangiocarcinoma

To increase resectability in patients affected by cholangiocarcinoma undergoing major hepatic resection, two methods of portal vein occlusion can be applied: radiological portal vein embolization (PVE) or surgical portal vein ligation (PVL). The rationale behind these approaches is to induce atrophy of the tumor-bearing lobe with subsequent hypertrophy in the contralateral lobe by diverting the portal venous flow into the liver section that is expected to remain. One limiting factor for performing major liver resection is the remaining liver volume (FLR): in the case of normal hepatic function, an FLR of approximately 25% is considered to be sufficient to maintain liver function after resection. A novel concept has recently been described, consisting of 2-staged extended hepatectomy with initial surgical exploration, PVL, and in situ liver splitting (ALPPS) to induce rapid hypertrophy, over a short period of time, of the future liver remnant (FLR) in patients with marginally resectable cholangiocarcinoma. The first step of this novel surgical approach consists of an in situ split liver procedure, with PVL and transection followed by definitive resection 9 days later. In general, it takes 2-6 weeks to achieve sufficient growth of the FLR for curative liver resection after PVE alone. A more rapid increase in FLR volume occurred after ALPPS; this decreased the time to surgery to a mean of 9 days, compared with 21-30 days after PVE. In addition, ALPPS induced an increase in the FLR also after failed PVE, rendering these patients resectable. Moreover, ALPPS involved complete separation of the FLR from the liver lobes to be resected. The accelerated hypertrophy effect observed with ALPPS, as compared to PVL and PVE alone, even with inclusion of segment IV, should be attributed to the "in situ" split procedure. This procedure leads to a complete devascularization of segment IV and also prevents formation of vascular collaterals between the left lateral and the right extended liver lobe. The combination of PVL and the in situ split procedure obviously induces a much stronger stimulus leading to rapid hypertrophy of the FLR.