Predictive risk factors of local recurrence after micro-waves under pringle maneuver for colorectal liver metastases

Abstract

Purpose: Hermoablative techniques might be considered as a valuable option for the treatment of colorectal liver metastases (CRLM). Immediate proximity with large vessels reduces the efficacy of such techniques due to the “heat sink effect” (HSE). Our group has previously published the microwaves (MWA) under Pringle maneuver to overcome the HSE. The aim of this study is to identify risk factors of in situ recurrence with the use of this technique. Method: We performed a prospective monocentric study. Patients with CRLM treated by MWA under Pringle maneuver for nodules ≤3cm next to large vessels (distance≤5mm). We collected characteristics of nodules, such as the size, the number, and the localisation. Post-operative complications, their severity and rate of recurrence were also identified. Results: Thirty-eight patients with forty-nine CRLM treated by MWA under Pringle maneuver were included. Nine (18%) in situ recurrence occurred. In nodules with local recurrence, median size of nodules was 22mm [IQR 14 – 26 mm]) versus 16.5mm [IQR 15-20 mm] in the absence of recurrence (p=0.16). However, in situ recurrence rate was significantly higher in nodules larger than 2 cm (5/13 vs 4/36; p=0.02). Among nodules located in segments VII, VIII and IVa, 9/28 (32%) presented in situ recurrence compared to none for the other segments (p=0.004). In multivariate analysis, the localisation in the hepatic dome was the only predictive factor of in situ recurrence (p=0.001). Conclusion: Despite interesting results, MWA under Pringle maneuver was less effective in nodules located in segments VII, VIII and IVa, especially in nodules larger than 2 cm.