Surgeon experience and outcomes: specific, analogy-based and cumulative learning in cardiac surgery

OBJECTIVES

To assess how different learning mechanisms, including specific learning, analogy-based learning, and cumulative experience, influence surgical outcomes following coronary artery bypass graft (CABG), aortic valve replacement (AVR), and mitral valve reconstruction (MVR) surgeries.

METHODS

Between 2010 and 2023, 46 surgeons performed 21,269 cardiac surgeries (CABG, AVR, and MVR) at a major heart surgery center in Germany. Surgical proficiency was assessed using 30-day risk-adjusted mortality rate (RAMR) and risk-adjusted re-thoracotomy rate (RARR), calculated for each surgeon and adjusted using EuroSCORE II. Linear regression models examined associations between learning mechanisms and surgical outcomes.

RESULTS

Higher procedure-specific volume in the preceding quarter was significantly associated with a lower 30-day RAMR for CABG, demonstrating a decline of 0.49 percentage points (95% CI, -0.88 to -0.10; P = 0.014). Furthermore, analogy-based learning demonstrated a significant cross-procedural effect for CABG, as prior-quarter volumes of technically related procedures (AVR and MVR) exhibited significant non-linear associations with 30-day RAMR. For MVR, greater cumulative experience significantly reduced the RARR (-0.295; 95% CI, -0.55 to -0.03; P = 0.028). No significant volume-outcome associations were observed for AVR.

This analysis included 21,269 total procedures (12,706 CABG, 5,477 AVR, and 3,086 MVR) from 2010 to 2023. Surgeons had a mean specialist experience of 8.2 years (CABG), 10.3 years (AVR), and 11.9 years (MVR) and performed a mean of 12, 5.1, and 5.1 procedure-specific surgeries per quarter, respectively.

CONCLUSIONS

Maintaining consistent, procedure-specific practice and accumulating experience are crucial for improving cardiac surgery outcomes.