Data Extraction and Critical Appraisal
All titles and abstracts were reviewed by two independent reviewers. All full-texts met inclusion criteria were reviewed, and required data were also extracted. The extraction of data was performed by two independent reviewers, and if necessary, a third one was consulted. Data consisted of baseline characteristics, procedural features, and patients’ outcomes during follow-up period. The extracted factors related to the coagulopathy included the number of patients with postoperative bleeding, the number of patients undergoing reoperation for postoperative bleeding, and the amount of blood products transfusion (i.e., packed blood cells and fresh frozen plasma). The volume of transfused blood products was calculated as milliliter reported by studies, and each of packed cells was considered as 250 ml. The length of stent deployed in the descending aorta was categorized into two groups (less than or equals to 10 cm or more than 10 cm).
The mean length of stent reported by studies was applied for categorization. The type of surgery was also defined as elective or non-elective (i.e., emergency/urgent) so that studies with all patients undergoing elective or non-elective operations were identified, and those with a mixture of elective and non-elective operations did not enter into this categorization. In addition, we divided patients into groups by the stent type (i.e., Thoraflex Hybrid, E-vita, Frozenix, and Cronus) and the gender predominance among studies (we categorized into two groups based on the median of male percentage, ≤74% versus >74%). In all steps of systematic review, the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were used.2