Outcomes of proximal versus distal splenic artery embolization after trauma: a systematic review and meta-analysis

The objective of this systematic review and meta-analysis was to assess the outcomes after angioembolization in blunt trauma patients with splenic injuries and to examine specifically the impact of the technique used. Studies evaluating adult trauma patients who sustained blunt splenic injuries managed by angioembolization were systematically evaluated. The following data were required for inclusion: grade of splenic injury, indication for embolization, and site of embolization (proximal [main splenic artery] or distal [selective]). In addition, major (requiring splenectomy) or minor (not requiring splenectomy) rebleeding, infarction, and infection in relation to the site of embolization (proximal vs. distal) was required. Pooled outcomes were compared between proximal and distal embolizations. To eliminate between-study heterogeneity, a sensitivity analysis was conducted on three reduced sets of studies. Fifteen of 147 evaluated studies were included for analysis. All were retrospective cohort studies and incorporated a total of 479 embolized patients. The overall failure rate of angioembolization was 10.2% (range, 0.0-33.3%). Injury severity and basic demographics did not differ among the study populations. However, the indications for angioembolization (contrast extravasation, large amount of hemoperitoneum, or high-grade splenic injury) differed between the populations but were not associated with a change in the failure rates. Rebleeding was the most common reason for failure; however, it did not differ statistically between the used techniques, and with the 95% confidence interval crossing the 5% zone of clinical indifference, this result was inconclusive. Minor complications occurred statistically and clinically more often after distal than after proximal embolization. The available literature is inconclusive regarding whether proximal or distal embolization should be used to avoid significant rebleeding and larger prospective cohort studies are required. However, both techniques have an equivalent rate of infarctions and infections requiring splenectomy. Minor complications occur more often after distal embolization. This is primarily explained by the higher rate of segmental infarctions after distal embolization.