Fifty non-comparative studies (1,886 patients) were included in the review. Most studies were reported to be retrospective. No other quality issues were discussed.
Mortality: The pooled event ratio was 10.8% (95% CI 9.3% to 12.5%). Similar findings were reported by hybrid repair technique. Event rates were slightly higher when a stented elephant trunk technique was used (13.2%, 95% CI 7.8% to 21.4%; nine studies).
Neurologic outcomes: The pooled event ratio for stroke was 6.9% (95% CI 5.7% to 8.4%). Similar findings were reported for debranching and frozen elephant trunk techniques. Rates were higher for stented elephant trunk procedures (event ratio 10.9%, 95% CI 5.8% to 19.7%; eight studies).
The event ratio for perioperative spinal cord ischaemia was 6.8% (95% CI 5.6% to 8.2%). Slightly lower rates were reported in the debranching group and slightly higher rates were reported in frozen elephant trunk and stented elephant trunk groups.
Dissections: Similar event ratios were reported for all outcomes in patients who underwent all types of aortic dissection.
Analysis that compared zone 0 versus zone 1 showed a statistically significant higher risk of mortality in zone 0 (OR 2.8, 95% CI 1.17 to 6.7; 10 studies) but no differences for stroke and spinal cord ischaemia. Findings for other subgroup analyses were reported in the review.