J. C. Iannuzzi1, F. J. Fleming1, A. Chandra2, K. Rasheed2, A. Doyle2, K. Noyes1, J. R. Monson1, M. J. Stoner2 1University Of Rochester,Surgical Health Outcomes & Research Enterprise, Department Of Surgery,Rochester, NY, USA 2University Of Rochester,Vascular Surgery,Rochester, NY, USA
Introduction:
While much data on open abdominal aortic aneurysm (OAR) and endovascular abdominal aortic aneurysm repair (EVAR) has been reported, it has either succeeded in depth but with small sample size, or excelled in sample size but without depth. For the first time, the National Surgical Quality Improvement Program has released procedure-targeted data that allows enhanced analysis of aortic surgery. A greater understanding of repair technique and its associated mortality will lead to better clinical decision making, and informed patient care.
Methods:
The NSQIP database from 2011-2012 was analyzed for included cases of OAR and EVAR using Common Procedural Terminology Codes. Bivariate analysis was performed to identify procedure and patient characteristics associated with mortality within 30-days of the procedure. Factors meeting criteria of p<0.1 were assessed for inclusion into a manual stepwise multivariable binary logistic regression with mortality as the end point. Factors meeting p<0.05 in the final model were retained. Model performance was assessed using a c-statistic. OAR and EVAR were assessed separately as procedure specific data was unique to each operative approach.
Results:
A total 949 OAR cases and 2,785 EVAR cases were included in the NSQIP procedure targeted vascular dataset for 2011-2012. Mortality following OAR was 12.0% (n=114) and after EVAR was 3.8% (n=105). After controlling for OAR patient demographics (Age, ASA class, pulmonary comorbidity, elective case, & preoperative transfusion) the following procedure characteristics were independently associated with mortality on multivariable analysis: supraceliac proximal clamp (OR=2.02, 95% CI: 1.18-3.45, p=0.010], and juxtraenal proximal extent (OR=0.54, CI:0.32-0.91, p=0.021). In EVAR cases (after adjustment for age, ASA, pulmonary comorbidity, elective case, and obesity) the following were associated with mortality on multivariable analysis: Diameter as surgical indication (OR=0.41, CI:0.23-0.75, p=0.004), Rupture as surgical indication (OR=5.29, CI:2.83- 9.88, p<0.001), attempted percutaneous access converted to cutdown (OR=4.42, CI:1.16, 16.77, p=0.029), acute conversion to open (OR=7.18, CI:2.078-24.79, p=0.002), juxtarenal proximal extent (OR=3.06, CI: 1.46-6.42, p=0.003), Type IV thoracoabdominal aneurysm (OR=8.16, CI:1.98-33.64, p=0.004), and lower extremity ischemia (OR=2.29, CI:1.09-4.82, p=0.030). The C-statistic in the OAR model improved with inclusion of procedure specific data from 0.818 to 0.829, and in the EVAR model from 0.852 to 0.881 suggesting significantly improved model performance with the inclusion of procedure specific data.
Conclusion:
Procedure specific data improved mortality modeling using with anatomic considerations being most prominent in OAR. In EVAR cases, not only were anatomic data important, but also percutaneous access with over 4 times the adjusted odds of death when percutaneous was attempted but failed.