How can we safely climb the ALPPS?

Abstract

R0 resection with zero mortality is the ultimate goal for hepatobiliary surgeons, especially for the treatment of extensive hepatobiliary malignancies. The safety of liver resection is dependent on the function of the future liver remnant (FLR), and an inadequate FLR volume is related to a significant increase in postoperative mortality and morbidity. Therefore, various criteria for the FLR volume have been proposed to secure the safety of major hepatectomies according to the extent of underlying injury in the liver [1–5]. However, these criteria for FLR volume often cause clinical dilemmas for surgeons in determining the surgical indications for patients with small FLR volumes because the safety of surgery and oncological radicality are, by nature, conflicting factors. In the history of hepatobiliary surgery, there have been two outstanding approaches for the safe management of patients with very small FLR volumes. The first was the development of techniques that manipulate the portal blood flow to induce hypertrophy of the FLR. Initially achieved using portal vein ligation (PVL) [6–8], these techniques have evolved toward percutaneous portal vein embolization (PVE) [9–12]. Increasing evidence has suggested that hypertrophy of the FLR induced by portal flow modulation is associated with an improved safety of major hepatectomies [3, 10, 13]. In addition, dynamic volume parameters, such as the degree of hypertrophy [13] or the kinetic growth rate [14], are also very informative for estimating the histologic quality and functional reserve of the underlying liver. The second noteworthy approach was the ‘‘twostage surgery’’ for the resection of multiple bilobar hepatic lesions. This sequential procedure was initially proposed by surgeons at the Hopital Paul Brousse in Paris, France, with the expectation of allowing interim liver regeneration between the two sequential hepatic resections [15]. An oncological advantage of the two-stage approach has been reported in patients with extensive colorectal liver metastases [16], and this procedure used in conjunction with or without PVE has been adopted by numerous hepatobiliary centers. These two evolutional approaches have expanded the indications for surgery, and many patients with extensive liver tumors have benefited from surgery using these approaches. However, a remaining issue is that these approaches require at least several weeks to complete the entire clearance of the tumor burden within the liver. Some authors have suggested a risk of tumor progression during the waiting time after PVE [17, 18]. Therefore, the time lag between the preoperative intervention and resection can be critical, especially for the treatment of patients with borderline resectable tumors and/or oncologically highly aggressive tumors. A recent notable paper in the field of hepatobiliary surgery was a case series introducing a new surgical procedure known as ‘‘ALPPS’’ (Associating Liver Partition with Portal vein ligation for Staged hepatectomy) that enables the rapid growth of the FLR [19]. The first stage of this procedure includes a right PVL and the in situ splitting of the liver along the umbilical fissure or the main portal fissure. Schnitzbauer et al. [19] reported that a 74 % volume increase was observed in the FLR at a median of 9 days after the first procedure. Immediately after its publication, this article triggered a large number of reactions from all over the world. Although the clinical outcomes demonstrated in this paper were very impressive and all the patients were able to proceed to a right N. Kokudo (&) J. Shindoh Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan e-mail: KOKUDO-2SU@h.u-tokyo.ac.jp