Conversion during Minimally Invasive Left Pancreatectomy: A Nationwide Study of Causes and Consequences

To identify risk factors for conversion, develop a predictive Conversion Risk Score (CRS), and assess the association between conversion and severe postoperative complications.

Conversion occurs in 15-30% of minimally invasive left pancreatectomies (MILP). Risk factors and potential negative impacts on postoperative outcomes are poorly described.

Retrospective, nationwide, multicenter study including all MILP (laparoscopy and robot) performed between 2010 and 2021. Risk factors for conversion were identified by multivariate mixed model, and a CRS was developed on a "training-set" and validated (calibration diagrams and ROC curves) on a "validation-set." The association between severe complications and conversion was assessed using a propensity score based on the main risk factors for severe complications: age, sex, BMI, ASA score, tumor malignancy, multi-organ resection, operative duration, blood loss, splenectomy.

2104 patients included from 55 centers. Conversion occurred in 15.6% of MILP. Its risk factors were male sex (OR=1.67;P=0.048), BMI≥25 kg/m2 (OR=2.15;P=0.004), history of laparotomy (OR=2.9;P<0.001), initial pancreatitis (OR=3.58;P=0.007), tumor size≥40 mm (OR=2.12;P=0.003), planned splenectomy (OR=2.63;P<0.001), unplanned splenectomy (OR=4.05;P=0.028), portal vein resection (OR=36.3;P=0.002), multi-organ resection (OR=12.97;P<0.001). A predictive CRS was created based only on preoperatively available variables (the first six), with scores ranging from 0 to 7, corresponding to a conversion risk of 2% to 100%. No association was observed with tumor malignancy, robotic approach, or pancreatectomy volume. Conversion was significantly associated with severe complications [OR=1.80(1.16-2.54)], independent of other risk factors for complications.

Conversion during MILP can be predicted by CRS, aiding surgeons in decision-making, given its significant association with severe complications.