Surgical Risk Calculator

Open Aortic Aneurysm Repair Mortality Risk Index

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Estimates 30-day mortality after elective open repair of an infrarenal abdominal aortic aneurysm.

Who this applies to, and differences from the paper's table and the original spreadsheet

The study left out ruptured aneurysms and patients who also had visceral-renal bypass or suprarenal aortic surgery.

This page uses the risk index published in 2013. The original spreadsheet, posted in September 2012, is an earlier model from the manuscript as first submitted. It uses hemiplegia and functional status and does not use sex or platelets, so it gives different numbers. It is no longer offered.

Risks here come from the formula in the paper's Methods: the logit is −4.981 + 0.3 × total points. The paper prints the intercept without its minus sign. This formula gives the printed Table IV except in two places:

  • For 17 to 20 points, Table IV prints 47.03%, 39.68%, 32.76% and 26.52%. These are 100% minus the risk, so risk seems to fall as points rise. This page shows 52.97%, 60.32%, 67.24% and 73.48%.
  • For 11 points, Table IV prints 15.4%. This page shows 15.70%.
Dyspnea
Previous peripheral revascularization or amputation History of peripheral arterial disease requiring revascularization or amputation
Age
Creatinine over 1.5 mg/dL Preoperative creatinine
Abnormal platelets Platelets below 150,000/mm³ or above 350,000/mm³
Sex

About this model

  • Built from 2,845 patients having elective open repair in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP), 2007–2009.
  • 30-day mortality was 3.3% (95 patients).
  • C statistic 0.72. The Hosmer-Lemeshow test gave χ² 4.76, P = .57.
  • Mortality seen in each risk group: 2.5% of 2,508 patients in the low group, 7.2% of 278 in the intermediate group, and 22.0% of 59 in the high group.
  • The paper states that the index awaits validation in subsequent studies.

Points (Table III of the paper)

Risk factorPoints
Dyspnea: none0
Dyspnea: on moderate exertion2
Dyspnea: at rest8
Previous peripheral revascularization or amputation3
Age: 65 years or younger0
Age: over 65 years3
Creatinine over 1.5 mg/dL2
Abnormal platelets2
Sex: male0
Sex: female2

Risk by total points (Table IV of the paper, corrected as explained above)

No combination of answers gives 1 or 19 points.

Total pointsEstimated riskRisk group
00.68%Low
10.92%Low
21.24%Low
31.66%Low
42.23%Low
52.99%Low
63.99%Low
75.31%Low
87.04%Intermediate
99.27%Intermediate
1012.12%Intermediate
1115.70%Intermediate
1220.08%High
1325.33%High
1431.41%High
1538.20%High
1645.49%High
1752.97%High
1860.32%High
1967.24%High
2073.48%High

Citation

Ramanan B, Gupta PK, Sundaram A, Gupta H, Johanning JM, Lynch TG, MacTaggart JN, Pipinos II. Development of a risk index for prediction of mortality after open aortic aneurysm repair. J Vasc Surg. 2013;58(4):871-8. doi:10.1016/j.jvs.2013.03.024 · PubMed 23676190

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