Monosegment ALPPS hepatectomy preserving segment 4 for colorectal liver metastases: literature review and our experience.

Monosegment 4±1 Associating Liver Partition and Portal Vein ligation for Staged hepatectomy (ALPPS) for bilateral colorectal liver metastases decreases the risk of drop-out of two stage hepatectomy, triggering a rapid and significant increase in future liver remnant (FLR) with promising oncological outcomes. We report two cases of segment 4+1 monosegment ALPPS for multiple colorectal liver metastases performed at our institution. In the literature, seven similar cases have been reported. Short and long term outcomes of our two patients were reported along with a review of data from the literature. Our patients showed a FLR increase from 13% to 37% and from 14% to 41% of total liver volume, respectively. This was compared to a median growth from 19% at baseline to 34% before stage 2, in the literature. After 20 and 27 months since resection both patients are alive and disease-free. In the literature, median overall survival and disease free survival were 13 months (range, 5-24 months) and 5 months (range, 3-23 months), respectively. Segment 4±1 ALPPS is associated with promising oncological outcomes and a significant FLR growth. It may be safely performed in selected patients as a salvage procedure, reducing the risk of the dropout of two-stage hepatectomy.