Prognostic Impact of Pedicle Clamping during Liver Resection for Colorectal Metastases

SIMPLE SUMMARY: During liver resection for colorectal cancer metastases, the flow of blood into the liver can be technically interrupted, which is also referred to as pedicle clamping or the Pringle maneuver. The effect on long-term oncologic outcomes is still under debate with respect to mechanisms of ischemia-reperfusion as well as transfusion demand and earlier disease recurrence. In this retrospective cohort study, the effect of pedicle clamping on the overall and disease-free survival of 336 patients undergoing curative resection for colorectal cancer liver metastases was analyzed with univariate, multivariate, and propensity-score methods. Favorable long-term outcomes and lower rates of increased transfusion demand were observed in patients with pedicle clamping while no increased postoperative morbidity was monitored. Further prospective evaluation of potential oncologic benefits of pedicle clamping in these patients may be meaningful. ABSTRACT: Pedicle clamping (PC) during liver resection for colorectal metastases (CRLM) is used to reduce blood loss and allogeneic blood transfusion (ABT). The effect on long-term oncologic outcomes is still under debate. A retrospective analysis of the impact of PC on ABT-demand regarding overall (OS) and recurrence-free survival (RFS) in 336 patients undergoing curative resection for CRLM was carried out. Survival analysis was performed by both univariate and multivariate methods and propensity-score (PS) matching. PC was employed in 75 patients (22%). No increased postoperative morbidity was monitored. While the overall ABT-rate was comparable (35% vs. 37%, p = 0.786), a reduced demand for more than two ABT-units was observed (p = 0.046). PC-patients had better median OS (78 vs. 47 months, p = 0.005) and RFS (36 vs. 23 months, p = 0.006). Multivariate analysis revealed PC as an independent prognostic factor for OS (HR = 0.60; p = 0.009) and RFS (HR = 0.67; p = 0.017). For PC-patients, 1:2 PS-matching (N = 174) showed no differences in the overall ABT-rate compared to no-PC-patients (35% vs. 40%, p = 0.619), but a trend towards reduced transfusion requirement (>2 ABT-units: 9% vs. 21%, p = 0.052; >4 ABT-units: 2% vs. 11%, p = 0.037) and better survival (OS: 78 vs. 44 months, p = 0.088; RFS: 36 vs. 24 months; p = 0.029). Favorable long-term outcomes and lower rates of increased transfusion demand were observed in patients with PC undergoing resection for CRLM. Further prospective evaluation of potential oncologic benefits of PC in these patients may be meaningful.