Is the extent of functional liver remnant increase truly “functional”? A single-institution case series of patients with associating liver partition and portal vein ligation for staged hepatectomy (ALPPS)

Introduction:
Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) aims to induce rapid hypertrophy of the future liver remnant (FLR) to reduce the risk of post-hepatectomy liver failure (PHLF). However, volumetric increase does not correspond to functional increase. This is a novel study which aims to compare the increase in standardized FLR (sFLR) vs. indocyanine green retention at 15 minutes (ICG-R15).

Material and methods:
This is a retrospective case series of patients who underwent ALPPS between May 2015 and January 2022. Primary outcomes were sFLR and ICG-R15. Secondary outcomes were incidence of PHLF, morbidity, recurrence, overall survival (OS) and disease-free survival (DFS).

Results:
There were 10 patients with median age of 60.5 years (range 29-69). Most patients had adenocarcinoma secondary to colorectal origin (80%). There were 7 patients who received neoadjuvant chemotherapy [median 6 cycles (range 5-9)]. Median size of the primary tumour was 5.0 cm (range 2.0-7.0 cm). There was a significant increase in median ICG-R15 after stage 1 ALPPS (8.8% vs. 10.2%, p = 0.024) and increase in median sFLR after stage 1 ALPPS (34.4% vs. 53.0%, p = 0.012). Linear regression showed no significant correlation between sFLR increase and ICG-R15 (B = 0.26, 95% CI: –0.82, 1.34, p = 0.565). One patient had PHLF. Median time to local recurrence and metastatic recurrence was 14.4 months (range 6.9-21.9) and 7.5 months (range 6.9-17.3) respectively. OS and DFS were 50% and 40% respectively.

Conclusions:
No significant relationship was observed between ICG-R15 and sFLR. Volume increase may overestimate the functional increase following ALPPS. Larger studies are needed to validate our findings.