Hypertrophy and Liver Function in ALPPS: Correlation with Morbidity and Mortality

<b><i>Background:</i></b> ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) was introduced with the promise to reduce posthepatectomy liver failure (PHLF) in extended hepatectomies but has higher morbidity and mortality rates compared to conventional methods of volume enhancement. There are few studies of the incidence of PHLF after ALPPS and little information on how to avoid PHLF by functional testing. It remains unclear what causes the compromise in liver function despite rapid volume gain and if any of the modifications proposed reduce the incidence of PHLF. This review summarizes published data on this topic. <b><i>Methods:</i></b> This is a systematic review that studies literature on the incidence of liver failure and assessment of liver function following ALPPS as well as modifications of the existing technique. Articles were searched in PubMed, evaluated, selected, and tabulated. <b><i>Results:</i></b> The literature search revealed 326 articles that met the selection criteria. PHLF criteria as defined by the International Study Group of Liver Surgery (ISGLS) were the most commonly used criteria, but PHLF was frequently not defined. PHLF occurred most frequently after stage 2 of ALPPS at around 30% in most larger studies. Hepatobiliary scintigraphy showed a discrepancy between volume and functional growth of the liver. Function increase was only 50% compared to volume increase. Mechanistic explanations using histologic analyses have been given to explain the immaturity of the liver after rapid hypertrophy. Modifications of ALPPS showed a comparable volumetric gain when compared to classic ALPPS, but data were lacking to assess PHLF. <b><i>Conclusion:</i></b> ALPPS has relatively high rates of PHLF, morbidity, and mortality. This may be explained by data demonstrating functional growth when compared to volume growth. ALPPS should not be performed without functional assessment and with caution.