Modifications of ALPPS - from complex to more complex or from complex to less complex operations

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has recently been developed to induce rapid liver hypertrophy to reduce the chance of post-hepatectomy liver failure in patients with borderline or insufficient future liver remnant. ALPPS is still in an early developmental stage and its techniques have not been standardized. This study aimed to review the technical modifications of the conventional ALPPS procedure. DATA SOURCES: Studies were identified by searching MEDLINE and PubMed for articles published from January 2007 to December 2016 using the keywords associating liver partition and portal vein ligation for staged hepatectomy and ALPPS. Additional articles were identified by a manual search of references from key articles. RESULTS: There have been a lot of modifications of the conventional ALPPS. These are classified as: (1) modifications aiming to improve surgical results; (2) modifications aiming to expand surgical indications; (3) salvage ALPPS; (4) ALPPS using the minimally invasive approach. Some of these modifications have made the conventional ALPPS procedure to become even more complex, although there have also been other attempts to make the procedure less complex. The results of most of these modifications have been reported in small case series or case reports. We need better well-designed studies to establish the true roles of these modifications. However, it is interesting to see how this conventional ALPPS procedure has evolved since its introduction. CONCLUSIONS: There is a trend for the use of minimally invasive procedure in the phase 1 or 2 of the conventional ALPPS procedure. Some of these modifications have expanded the use of ALPPS in patients who have been considered to have unresectable liver tumors. The long-term oncological outcomes of these modifications are still unknown.