Effect of Pringle maneuver on prognosis of patients with colorectal cancer liver metastases after liver resection: a meta-analysis.

Purpose: Pringle maneuver (PM) is a double-edged sword in liver resection, which is beneficial in reducing blood loss but also causes ischemia-reperfusion injury which may stimulate the outgrowth of micrometastases. The impact of PM on tumor recurrence remains controversial. This study aimed to assess whether PM has effect on the prognosis of colorectal cancer liver metastases (CRLM) after hepatectomy.

Methods: PubMed and the Cochrane Library databases were searched. The PM is defined as the portal triad clamping for several minutes, followed by several minutes of reperfusion, repeated as needed. Prolonged PM was defined as continuous clamping ≥ 20 min or ≥ 3 cycles for maximally 15-min intermittent ischemia.

Results: Eleven studies encompassing 4054 patients were included in this meta-analysis. The pooled hazard ratio (HR) did not show significant differences between PM and non-PM groups for disease-free survival (DFS) (HR = 0.91, 95% confidence interval (CI) 0.76-1.11, P = 0.36) and overall survival (HR = 1.03, 95% CI 0.76-1.39, P = 0.87). Subgroup analysis revealed that prolonged PM has adverse impact on DFS (HR 1.75, 95% CI = 1.28-2.40, P = 0.0005). However, non-prolonged PM is a protective factor for DFS (HR 0.82, 95% CI = 0.73-0.92, P = 0.001).

Conclusion: These findings suggested that prolonged PM may have an adverse impact on the DFS of patients with CRLM and non-prolonged PM is a protective factor for DFS. Further prospective multicenter studies are warranted.