Optimal Future Liver Remnant in Patients Treated with Extensive Preoperative Chemotherapy for Colorectal Liver Metastases

Abstract

Patients with colorectal liver metastases (CLM) are increasingly treated with preoperative chemotherapy. Chemotherapy associated liver injury is associated with postoperative hepatic insufficiency (PHI) and mortality. The adequate minimum future liver remnant (FLR) volume in patients treated with extensive chemotherapy remains unknown. All patients with standardized FLR>20%, who underwent extended right hepatectomy for CLM from 1993-2011, were divided into three cohorts by chemotherapy duration: no chemotherapy (NC, n=30), short duration (SD, ≤12weeks, n=78), long duration (LD, >12weeks, n=86). PHI and mortality were compared by using uni-/multivariate analyses. Optimal FLR for LD chemotherapy was determined using a minimum p-value approach. A total of 194 patients met inclusion criteria. LD chemotherapy was significantly associated with PHI (NC+SD 3.7 vs. LD 16.3%, p=0.006). Ninety-day mortality rates were 0% in NC, 1.3% in SD, and 2.3% in LD patients, respectively (p=0.95). In patients with FLR>30%, PHI occurred in only two patients (both LD, 2/20, 10%), but all patients with FLR>30% survived. The best cutoff of FLR for preventing PHI after chemotherapy >12weeks was estimated as >30%. Both LD chemotherapy (odds ratio [OR] 5.4, p=0.004) and FLR≤30% (OR 6.3, p=0.019) were independent predictors of PHI. Preoperative chemotherapy >12weeks increases the risk of PHI after extended right hepatectomy. In patients treated with long-duration chemotherapy, FLR>30% reduces the rate of PHI and may provide enough functional reserve for clinical rescue if PHI develops.