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

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.

Insurance Status Predicts Access To Care And Outcomes Of Vascular Disease

OBJECTIVES:
To determine if insurance status is predictive of severity of vascular disease at the time of treatment and of outcomes following intervention.

METHODS:
Hospital discharge databases from Florida and New York from 2000-2004 were analyzed for lower extremity revascularization (LER, n=59,833), carotid revascularization (CR, n=97,927), and abdominal aortic aneurysm (AAA, n=29,599), repair using ICD-9 codes for diagnosis and treatment. The indications for intervention as well as the post-operative outcomes were examined assigning insurance status as the independent variable. Patients insured under health maintenance organizations (HMO), Medicare, Medicare HMO, commercial insurers, Medicaid HMO, the Department of Veterans Affairs, Blue Cross, or other federal programs (Insurance Group A) were compared to those with Medicaid or without insurance (Insurance Group B).

RESULTS:
Patients without insurance or with Medicaid (Group B) are at a greater than twofold risk of presenting with ruptured AAA compared to those in insurance Group A; while the post-operative mortality rates after elective AAA repair is quite similar between the groups. Patients in Group B present with symptomatic carotid disease nearly twice as often as those in Group A, but stroke rates after CR did not differ significantly. Patients with Medicaid or without insurance are more likely to present for LER with limb threatening ischemia vs. claudication. In contrast to AAA repair and CR, the outcomes of LER were diminished in Group B patients, with a higher rate of post-operative amputations compared to Group A. (Table 1 and Table 2).

Carotid Angioplasty And Stenting And Carotid Endarterectomy In The Community — Analysis Of Outcomes Using Large Data Sets

Leila Mureebe, Natalia Egorova2, Chihui Fang2, Jeannine K. Giacovelli2, James F. McKinsey1, Peter L. Faries1, Annetine Gelijns2, Alan J. Moskowitz2, K. Craig Kent.1

1. New York Presbyterian Hospital, New York, NY;
2. International Center for Health Outcomes and Innovation Research; Columbia University College of Physicians and Surgeons, New York, NY.

OBJECTIVES:
Medicare approved a distinct code identifying carotid angioplasty and stenting (CAS) in 2004. We sought to identify rates and risks for mortality and post-operative stroke in patients undergoing CAS and carotid endarterectomy (CEA) in a large population dataset.

METHODS:
Hospital inpatient discharge data from California and New York for the year of 2005 were queried for patients who underwent either CEA or CAS. Comorbidities present on admission that were associated with or might impact the outcome of carotid intervention were surveyed. Odds ratios were calculated by multivariable logistic regression for predictors of mortality and post-operative stroke in all patients who underwent either CEA or CAS.

RESULTS:
There were 14,785 CEA and 2,554 CAS performed during the period evaluated. Mortality for patients undergoing CAS was double that of CEA (CAS 1.41%, CEA 0.64%, p<0.0001), as was the risk of post-operative stroke (2.19% for CAS, 1.24% for CEA, p=0.002). To determine if outcomes for CAS differed from CEA in a high-risk population, we identified a subset of patients with significant comorbidities which included arrhythmia, acute myocardial infarction. renal failure, congestive heart failure and respiratory failure and anatomic abnormalities including neck irradiation or previous surgery. There were 7,996 patients in this cohort (46.1% of all patients undergoing CAS and CEA). Using multivariable logistic regression CAS was a predictor of both stroke (odds ratio: 1.820; 95% confidence interval: 1.262-2.625) and mortality (odds ratio: 2.604; 95% confidence interval: 1.583-4.284) in this high-risk group.

CONCLUSIONS:
In all patients undergoing CAS or CEA, CEA is associated with a lower mortality and lower post-operative risk of stroke. Although patients who underwent CAS had significantly more comorbid conditions, CAS is an independent predictor of both postoperative stroke and death in both low risk and high risk populations. CEA remains a safe option for most patients who require carotid intervention.