Undergoing an endovascular repair instead of an open repair of abdominal aortic aneurysms confers a modestly greater likelihood of survival, but higher reintervention and rupture rates, according to a retrospective study published in the September JAMA Surgery.
“[U]nlike the clinical trial results, we found the survival advantage for [endovascular] repair to be maintained until 3 years postoperatively,” write David C. Chang, PhD, MPH, MBA, from the Massachusetts General Hospital Department of Surgery and Harvard Medical School in Boston, and colleagues. “Given that the major risk factor for [abdominal aortic aneurysm] is smoking, this advantage would inevitably erode as cardiovascular disease, emphysema, and pulmonary malignancy exact their toll.”
The researchers analyzed the outcomes of 23,670 California inpatients requiring repair of abdominal aortic aneurysms between 2001 and 2009, with a median follow-up of 3.3 years. Slightly more than half (51.7%) received endovascular repairs, and these patients had a lower rate of 30-day mortality for any reason (1.54%), compared with those who underwent an open repair (4.74%).
Excluding the early deaths, rates of readmission for any reason and rates of pneumonia within 30 days were similar between both groups. Sepsis was slightly more common among those with open repairs (0.50% open vs 0.38% endovascular), but surgical site infections were less common (0.91% open vs 1.16% endovascular).
For the first 3 years after the procedure, patients with endovascular repair had lower mortality than open repair patients, with a difference ranging from 1 to 3 percentage points. The pattern flips at the third year, however, with mortality among endovascular repair patients exceeding that of open repair patients, albeit without statistical significance for the long-term trend. “We believe this is explained by the willingness of the surgeon to undertake [endovascular] repair in older patients knowing that the less-invasive procedure is safer than open repair,” the authors explain.
Overall mortality did not differ among the two groups (hazard ratio, 0.99; 95% confidence interval, 0.94 – 1.04; P = .64) after adjusting for potential confounders including age, race/ethnicity, sex, insurance types, Charlson Comorbidity Index score, calendar year, scheduled vs unscheduled admissions, and teaching vs nonteaching hospital type.
Reintervention rates for patients with endovascular repair exceeded those with open repair throughout the follow-up. At 1 year, 0.55% of open repair patients and 1.43% of endovascular repair patients required reintervention. By year 5, the gap had grown larger, with 1.48% of open repair patients and 6.59% of endovascular repair patients requiring reintervention.
Rupture rates also remained consistently higher among patients with endovascular repair than among those with open repair. No patients with open repair experienced a rupture until the second year, when 0.03% did compared with 0.41% at that time among those with endovascular repair. By year 5, a total of 0.16% of patients with open repair and 1.03% of patients with endovascular repair had experienced a rupture.
Among the patients who required a repeat abdominal aortic aneurysm repair, more than a third (38%) had an open re-repair. Among those requiring a re-repair, 31% of those with original endovascular repair and 62% of those with originally open repairs required an open re-repair.
“By examining longitudinal outcomes in a population (the most populous state, no less), the study by Chang et al serves as a good example of how to advance health services research, especially in surgery,” write Jamie E. Anderson, MD, and James W. Holcroft, MD, from the University of California Davis Medical Center in Sacramento, in an accompanying commentary. “The goal now is to do more…. Through the development of more sophisticated databases, ideally through electronic medical records that can support patient care while simultaneously aggregating and analyzing data, we can move beyond research focused on a snapshot of information to dynamic, real-time, population-based feedback.”
They suggest that this approach to ongoing data sharing and comparison can improve the efficiency of medical care and allow for more immediate interventions when appropriate.
“The study by Chang et al offers a glimpse into the future of population-based health services research methods,” Dr Anderson and Dr Holcroft write. “With the dawn of electronic medical records and big data, we should be able to develop surgical outcomes research that can compete with and complement the randomized trial.”
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