title: Outcomes of acute intraoperative surgical conversion during endovascular aortic aneurysm repair.
abstract: OBJECTIVE
  Outcomes and predictors of acute surgical conversion during endovascular aortic aneurysm repair (EVAR) were examined using the American College of Surgeons-National Safety and Quality Improvement Project (ACS-NSQIP) Database (2005 to 2008).
  
  
  METHODS
  Acute intraoperative surgical conversions occurring during elective EVAR were identified using Current Procedural Terminology codes. Nonemergent EVAR and primary open surgical repairs of infrarenal aneurysms were examined for comparison. Perioperative morbidity was categorized as wound, pulmonary, venous thromboembolic, genitourinary, cardiovascular, operative, and septic. Mortality, overall morbidity, and length of stay (LOS) were examined.
  
  
  RESULTS
  We identified 72 acute conversions, 2414 open repairs, and 6332 EVAR without acute conversion. Demographics and comorbidities were generally similar among operative groups. Mean operative time was 274 minutes for acute conversion vs 226 minutes for primary open repair and 162 minutes for EVAR (conversion vs EVAR and open repair vs EVAR P < .0001 for each; conversion vs open repair P = .0014; analysis on rank operative time). Blood transfusion was required in 69% of acute conversions (mean volume, 6.0 units) vs 73% of open repairs (mean volume, 3.3 units) and 12% of EVARs (mean volume, 2.6 units; P < .0001 for each pair-wise comparison; analysis on rank number of units among those transfused). 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. Median (quartile 1, quartile 3) LOS was 7 (5, 9) days for acute conversion and open repair, and 2 (1, 3) days for EVAR. Morbidity and mortality were significantly higher for acute conversion and open repair vs EVAR. The OR (95% confidence interval) for morbidity was 2.9 (1.7-4.8) after conversion and 2.8 (2.5-3.2) after open repair (P < .0001 for both) and for mortality was 3.4 (1.0-10.9; P = .0437) for conversion and 2.5 (1.9-3.5; P < .0001) for open repair. Morbidity and mortality were similar between acute conversion and open repair. A similar pattern among repair groups was demonstrated for LOS, with similar LOS for acute conversions and open repair, which were significantly longer than those observed for EVAR. No significant demographic or medical risk factor predictors of acute conversion during EVAR were identified.
  
  
  CONCLUSIONS
  Acute surgical conversion was a rare complication affecting 1.1% of EVAR cases, with no broadly identifiable at-risk population. When conversion did occur, morbidity and mortality rates paralleled those observed for elective open repair.
authors.affiliation: Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Newton
authors.forename: Mrinal
authors.initials: M
authors.lastname: Shukla
authors.forename: Jeanette S
authors.initials: JS
authors.lastname: Andrews
authors.forename: Kimberley J
authors.initials: KJ
authors.lastname: Hansen
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Corriere
authors.forename: Philip P
authors.initials: PP
authors.lastname: Goodney
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Edwards
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001014:Aortic Aneurysm / Q000401:mortality / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000401:mortality; D002318:Cardiovascular Diseases / Q000209:etiology; D016009:Chi-Square Distribution; D019992:Databases as Topic; D057510:Endovascular Procedures / Q000009:adverse effects* / Q000401:mortality; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology; D007902:Length of Stay; D016014:Linear Models; D016015:Logistic Models; D008171:Lung Diseases / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality / Q000628:therapy; D058996:Quality Improvement; D019984:Quality Indicators, Health Care; D006435:Renal Dialysis; D012086:Reoperation; D012121:Respiration, Artificial; D018570:Risk Assessment; D012307:Risk Factors; D018805:Sepsis / Q000209:etiology; D012955:Societies, Medical; D013530:Surgical Wound Infection / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000209:etiology