Monosegment ALPPS hepatectomy: Extending resectability by rapid hypertrophy

Background. Liver remnant function limits major liver resections to generally leave patients with >= 2 Couinaud segments. Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) induces extensive hypertrophy and allows surgeons to perform extreme liver resections. Methods. The international ALPPS registry (NCT01924741; 2011-2014) was screened for novel resection type with only 1 segment remnant. The anatomy of lesions and indications for ALPPS, operative technique, complications, survival, and recurrence were evaluated. Results. Among 333 patients, 12 underwent monosegment ALPPS hepatectomies in 6 centers, all for extensive bilobar colorectal liver metastases. All patients were considered unresectable by conventional means, and all had a response to or no progression after chemotherapy before surgery. In 2 patients, the liver remnant consisted of segment 2, in 2 of segment 3, in 6 of segment 4, and in 2 of segment 6. Median time to proceed to stage 2 was 13 days and median hypertrophy of the liver remnant was 160%. There was no mortality. Four patients experienced liver failure, but all recovered. Complications higher than Dindo-Clavien Ilia occurred in 4 patients with no long-term sequelae. At a median follow-up of 14 months, 6 patients are tumor free and 6 patients have developed recurrent metastatic disease. Conclusion. ALPPS allows systematic liver resections with monosegment remnants, a novelty in liver surgery. Because such resections are difficult to conceive without rapid hypertrophy, we propose to name such resections after the segments constituting the liver remnant rather than the segments removed.