Operator experience can predict success of EVAR

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At the recent, Annual Meeting of the Society for Vascular Surgery, researchers from the Vascular Surgery Division of New York-Presbyterian hospital System and the International for Health Outcomes and Innovated Research (InChoir) at Columbia University, NY, indicated that the minimum level for less experienced surgeons performing endovascular aneurysm repair (EVAR) is less than ten procedures.

Lead investigator, Dr James F McKinsey, (Columbia) highlighted the fact that although the use of EVAR technique (which was introduced in 2000) has markedly increased, there is little research about the relationship between physician experience in EVAR and clinical outcomes. As a result, the investigators established a study as to whether mortality and adverse events are predicted by a surgeon’s experience in endovascular repair of abdominal aortic aneurysms (AAAs) and evaluated the minimum experience needed for proficiency from the 2002-2004 National Medicare Database.

A total of 39,815 EVAR procedures were performed by 4,339 physicians from 2000-2004. The researchers identified patients with the ICD-9 procedure code 38.44 for EVAR and specific operating physician codes and patient demographics, co-morbidities, perioperative complications and 30-days mortality were evaluated. Multi-variable logistic regression models, student t-tests and chi-square analyses were used.

The number of procedures by less experienced surgeons decreased from 64% in 2001 to 30% in 2003. However, between 2003 and 2004 the total number of procedures reached a plateau at 3,500 per year, while EVARs performed by high experienced surgeons (with more than 50 procedures) only increased from 3% to 23%.

There was no significant difference in the age, gender, race and ethnicity for patients between the low-and high-experience surgeons. EVAR 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 of more than ten procedures. Multi-variable analysis showed that less than ten EVARs was an independent predictor of mortality, controlling for co-morbidities (OR 1.3). Likewise bleeding, respiratory, cardiac complications and urgent conversions to open repair were higher for the inexperienced surgeons.

To conclude, the investigators said that these data show significant reduction in perioperative complications and mortality with increased surgeon experience in EVAR. “About one-third of patients are being treated by less experienced surgeons and there are higher procedure-related complications and mortality, when controlling comorbidities,” said McKinsey. “Likewise bleeding, respiratory, cardiac complications and urgent conversions to open repair were higher for the inexperienced surgeons. Therefore guidelines for surgical accreditation need to be set.”