From IDEAL learning curve to team maturation: a decade of experience reducing conversion in laparoscopic liver resection.

BACKGROUND: Difficulty scoring systems overlook how a surgical team learns. We examined whether a structured team-based pathway (debriefing, risk stratification, protocolized decisions) was associated with a reduction in conversion in laparoscopic liver resection (LLR) without avoiding complex cases. METHODS: This single-center retrospective cohort study analyzed 2,051 pure LLRs (2009-2018), grouped by IDEAL phases: early, exploration, and maturation. The pathway was introduced in 2015. PRIMARY ENDPOINT: unplanned conversion. RESULTS: The overall conversion rate was 7.2% (147/2,051). Complex posterosuperior resections remained stable (15.8% to 12.3%, P = 0.120), yet conversion fell from 14.2% to 4.6% (P < 0.001). After adjustment for clinical covariates, the pathway period was associated with 53% lower odds of conversion (aOR = 0.47, 95%CI 0.33-0.65); however, when calendar year was added to the model, the pathway effect was no longer significant (aOR = 0.99, 95%CI 0.50-1.97), while year remained independently associated with lower conversion (aOR = 0.84 per year, 95%CI 0.75-0.94). CUSUM showed a biphasic learning curve crossing below zero at approximately the time of pathway introduction. Median total hospital stay shortened from 16.4 to 15.8 days (P = 0.006). Subgroup analyses suggested greater reductions in cirrhosis (45% RRR) and posterosuperior tumors (38% RRR). CONCLUSION: In this single-center experience, conversion fell substantially without simplifying case mix, but the improvement was associated with time and cumulative team experience rather than a specific pathway effect. The structured team-based approach may support, but not independently explain, this progression.