Outcomes of Acute Intraoperative Surgical Conversion During Endovascular Aortic Aneurysm Repair

Study Questions:

What are the outcomes and predictors of acute surgical conversion during endovascular aortic aneurysm repair (EVAR)?


Seventy-two acute conversions were identified from 2005-2008 using the American College of Surgeons–National Safety and Quality Improvement Project (ACS–NSQIP) database. A total of 2,414 open repairs and 6,332 EVARs without acute conversions were used for comparison of outcomes. Mortality, overall morbidity, and length of stay were determined for each group. Perioperative morbidity, specifically wound, pulmonary, venous thromboembolic, genitourinary, cardiovascular, operative, and septic complications were also noted.


Acute surgical conversion occurred in 1.1% of all EVAR cases in the ACS-NSQIP database. Demographics and comorbidities were similar in the patients undergoing acute conversions, open repairs, and EVARs without acute conversion. Mean operative time was 274 minutes for acute conversions, 226 minutes for primary open repairs, and 160 minutes for EVARs (p = 0.0014). Blood transfusion occurred in 69% of acute conversions, 73% of open repairs, and 12% of EVARs, although the number of units required was greater for acute conversions than for open repairs or uncomplicated EVARs (6 vs. 3.3 vs. 2.6 units, respectively; p < 0.001). Major morbidity was 28% for acute conversions, 28% for open repairs, and 12% for EVARs. Mortality was 4.2% for acute conversions, 3.2% for open repairs, and 1.3% for EVARs (odds ratio, 2.9, 2.8, and 1, respectively). Average length of stay was 7 days for acute conversions and open repairs, and 2 days for uncomplicated EVARs. There was no specific demographic or medical comorbidity identified that predicted acute conversion to open during EVAR.


The authors concluded that acute intraoperative surgical conversion during EVAR results in morbidity and mortality similar to those observed for elective open aneurysm repair.


Acute surgical conversion of elective EVAR is a rare event, and will be less common as endovascular devices become lower profile, increasingly more malleable to tortuous anatomy, and as experience with these devices continues to increase. It is surprising to note that morbidity and mortality associated with acute conversion is similar to open repair. Acute surgical conversion in the setting of the ruptured abdominal aortic aneurysm (AAA) may be more common, but this subset was not included in this study. It would be interesting to perform a similar analysis in patients who undergo acute surgical conversion for ruptured AAA, as there may be additional patient characteristics (in addition to anatomic criteria) that may better define those at risk for conversion in the emergent setting.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Blood Transfusion, Blood Vessel Prosthesis Implantation, Quality Improvement, Odds Ratio, Operative Time, Demography, Comorbidity, Cardiac Surgical Procedures, Vascular Surgical Procedures, United States

< Back to Listings