ALPPS monosegment resections allow a further extension of the limitations of resectability in colorectal liver metastases

Aims: The most extensive liver resections according to the Brisbane classification are right or left trisectionectomies, leaving two Couinaud-segments behind. The novel ALPPS technique (Associating Liver Partition and Portal Vein ligation for Staged hepatectomy) induces rapid and extensive liver regeneration prior to resection and recently led to case reports about resections leaving only one segment behind. Aim of this study was to evaluate the International ALPPS registry to see how many monosegment resections have been performed and to systematically evaluate their technique and outcome. Methods: Recordns of the international ALPPS registry (NCT01924741) from 2011 to 2014 were screened for liver resections leaving only 1 Couinaud segment or one segment and segment 1 as a liver remnant. Anatomy of tumors and indications for ALPPS, surgical technique, complications, survival and recurrence were evaluated. Results: Among 333 Patients undergoing ALPPS, 12 underwent ALPPS monosegment resections. All patients had colorectal liver metastases (CLRM) and had received chemotherapy prior to resection with either response or stable disease. Size of lesions and involvement of vascular pedicles justified the resectional approach. In 2 patients the remnant consisted of segment 2, in 2 of segment 3 , in 6 of segments 4 and 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 >IIIA Dindo-Clavien occurred in 4 patients with no long term sequelae. At a median follow-up time of 14 months, 6 patients are tumor free and 6 patients developed recurrent metastatic disease. Conclusions: ALPPS allows the systematic use of single segments liver remnants in patients with colorectal liver metastases, a novelty in liver surgery. In conjunction with chemotherapy this technique will allow a further extension of the limitations on resectability of CLRM.