During the study period 2616 patients from the sample underwent intact aneurysm repair. The cohort was 75.7% male with a mean age was 75.8 +/− 6.5. Nearly all (93.9%) patients were Caucasian, and 8.5% of patients received Medicaid during at least a portion of the study period.
The index procedure was performed by vascular surgeons in 49.8% of cases. Index procedures were also performed by other specialists including general surgeons (20.3%), cardiothoracic surgeons (19.3%), and physicians with other or undefined specialties (10.6%). There were no significant differences in gender, co-morbidity or poverty between those treated by vascular surgeons and those treated by other surgeons ().
On multivariate analysis (), only age greater than 85 was an independent predictor for receiving treatment by a vascular surgeon (OR 1.44, 95% CI 1.07 – 1.93; p < 0.02). Vascular surgeons were significantly more likely to perform AAA repair at high-volume centers (53% vs. 35%; p<0.0001). Vascular surgeons performed EVAR with similar frequency compared to other surgeons (61% vs. 58%, p= 0.08).
Multivariate logistic regression for factors predicting treatment by vascular surgeons
Overall mortality for the entire cohort was 2.6%. Mortality did not differ for patients cared for by vascular surgeons compared to others (2.5% vs. 2.7%, p=0.65; ). Mortality was equivalent by specialty for both OAR and EVAR ().
Complications and Mortality after AAA repairs
Outcomes by specialty and by operation type
Mortality for patients requiring re-intervention was significantly higher than for those not requiring re-intervention (22.5% vs. 1.5%; p < 0.0001, ). Mortality was also directly related to the number of reoperations required. Undergoing two or more re-interventions was associated with a significantly higher mortality compared to one required re-intervention (54% vs. 20%; p=0.0007, data not shown). Mortality was 50% after 2 or 3 re-interventions, and 100% after 4 re-interventions.
Post-operative complications requiring 152 re-interventions occurred in 142 (5.4%) patients. Re-interventions were more likely after OAR (9.5% vs. 2.7%, p<0.0001). The majority of complications were arterial (38%), respiratory (34%), or re-operative laparotomies (8.3%). There was no difference in reoperation rates between vascular surgeons and other surgeons (5.2% vs. 5.6%, p=0.65). Re-intervention rates after OAR and EVAR were similar for both surgeon types ().
Despite equivalent need for reoperation among specialties, the mortality after reoperation was nearly half for patients treated by vascular surgeons compared with other specialties (16.2% vs. 32.3%; p=.04, ). By repair type, mortality after reoperation was lower for vascular surgeons for OAR (15.6% vs. 33.3%, p=0.06) and EVAR (17.4% vs. 26.3%, p=0.48, ) but did not reach statistical significance.
Age greater than 75 was the only other variable associated with mortality after reoperation (29.2% vs. 11.3%, p = 0.02). Both vascular surgeon specialty (OR 0.33, 95% CI 0.1 – 0.9, p=0.03) and age > 75 (OR 3.77, 95%CI 1.18–12.03, p=0.03) remained independent predictors of re-operative mortality by multivariate analysis (). Mortality after complications was not associated with gender, race, co-morbidity, poverty, hospital procedural volume or type of repair. Likewise, by multivariate analysis the need for re-intervention was predicted by female gender and open repair. Patient age, co-morbidity, poverty, or hospital volume were not associated with the likelihood of re-interventions ().
Multivariate analysis of factors predicting mortality after re-intervention and re-intervention after AAA repair.
Mortality rates after reoperation varied depending on the complication type, physician specialty, and patient age. With regard to complication type, mortality was highest after reoperation for bowel obstruction (80%), colon resection (67%), or amputation (50%; ). Conversely, no deaths occurred after reoperation for wound complications, or abdominal infection. Differences in mortality based on surgeon specialty and complication type were largely accounted for by significantly lower mortality rates after reoperations for arterial complications for vascular surgeons compared to other specialties (30.8% vs. 52.0%, p=0.04, ). This difference was most pronounced after OAR (10.0% vs. 68.8%, p=.005). Lower mortality after arterial re-interventions for EVAR by vascular surgeons did not reach statistical significance when compared to other surgeons (13.3% vs. 30.0%, p=0.36).
Mortality after re-interventions by re-intervention and surgeon type