Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in colorectal liver metastases: review of the literature.

The liver is considered as one of the most common sites of metastasis and a key determining factor of survival in patients with isolated colorectal liver metastasis (CRLM). For longer survival of patients, surgical resection is the only available option. Especially in CRLM bilobar patients, to achieve R0 resection, maintaining an adequate volume of the future liver remnant (FLR) is the main technical challenge to avoid post-hepatectomy liver failure (PHLF). As standard procedures in the treatment of patients with severe metastatic liver disease, techniques such as portal vein embolization/portal vein ligation (PVE/PVL) accompanied by two-stage hepatectomy (TSH) have been introduced. These methods, however, have drawbacks depending on the severity of the disease and the capacity of the patient to expand the liver remnant. Eventually, implementation of the novel ALPPS technique ignited excitement among the community of hepatobiliary surgeons because ALPPS challenged the idea of unrespectability and extended the limit of liver surgery and it was reported that FLR hypertrophy of up to 80% was induced in a shorter time than PVL or PVE. Nonetheless, ALPPS techniques caused serious concerns due to the associated high morbidity and mortality levels of up to 40% and 15% respectively, and PHLF and bile leak are critical morbidity- and mortality-related factors. Carefully establishing the associated risk factors of ALPPS has opened up a new dimension in the field of ALPPS technique for improved surgical outcome by carefully choosing patients. The benefit of ALPPS technique is enhanced when performed for young patients with very borderline remnant volume. Adopting ALPPS technical modifications such as middle hepatic vein preservation, surgical management of the hepatoduodenal ligament, the anterior approach and partial ALPPS may lead to the improvement of ALPPS surgical performance. Research findings to validate the translatability of ALPPS' theoretical advantages into real survival benefits are scarce.