Surgeon Experience Predicts Outcomes For Elective Endovascular Aortic Abdominal Aneurysm Repair; Results From The National Medicare Database

Natalia N. Egorova¹, Giampaolo Greco¹, Jeannine K Giacovelli², Leila Mureebe², Peter Faries², Roman Nowygrod², Alan Moskowitz¹, Annetine Gelijns¹, Craig Kent², James F McKinsey.^2
1InCHOIR Columbia University, New York, NY;²New York Presbyterian Hospital System, New York, NY.

OBJECTIVES: The procedure code for endovascular repair of abdominal aortic aneurysm (EVAR) was introduced in 2000 and use of this treatment has markedly increased. Despite the rapid adoption of this technique, there is little research about the relationship between physician experience in EVAR and clinical outcomes. The objectives of this study are: (1) to determine whether mortality and adverse events are predicted by the experience of the surgeon; and (2) establish if there is a minimum experience needed for proficiency.

METHODS: We identified patients with the ICD-9 procedure code 38.44 for EVAR and specific operating physician codes from the Medicare Database (2000-2004). The cumulative physician experience with EVAR over 2000-2004 was used. Patient demographics, comorbidities, perioperative complications, and 30-days mortality were evaluated. Multivariable logistic regression models, student t-tests, and chi-square analyses were used.

RESULTS: 39,815 EVAR were performed by 4,339 physicians from 2000-2004. The number of procedures by low-experienced surgeons (<10 total EVAR) decreased from 64% in 2001 to 30% in 2003 and plateaued at 3,500/year between 2003-04, while EVARs performed by high experienced surgeons (> 50 procedures) increased from 3 to 23% (Fig. 1). There was no significant difference in the age, gender, race and ethnicity for patients between the low-and high-experience surgeons. EVARs performed by low experienced surgeons had a significantly higher 30-day mortality of 2.11%, whereas the mortality was in the range of 1.4-1.6% for surgeons with a cumulative experience > 10. Multivariable analysis showed that <10 EVARs was an independent predictor of mortality, controlling for comorbidities (Odds Ratio 1.3). Likewise bleeding, respiratory, cardiac complications and urgent conversions to open repair were higher for the inexperienced surgeons (Table 1).

CONCLUSIONS: These data show significant reduction in perioperative complications and mortality with increased surgeon experience in EVAR. Since about 1/3 of patients are being treated by low experienced surgeons with a higher procedure-related complications and mortality, guidelines for surgical accreditation need to be set. Our data indicate that this minimum experience level is greater than 10 procedures.