Prophylactic embolization vs observation for high-grade blunt trauma splenic injury: a systematic review with meta-analysis
Authors: Nann Silas , Clark Molly , Kovoor Joshua , Jog Shivangi , Aromataris Edoardo 
Published: July 2024

Objective:
The objective of this systematic review was to compare the effectiveness of prophylactic angioembolization with observation as primary management strategies for patients with high-grade (grades 3-5) blunt trauma splenic injury.

Introduction:
The spleen is commonly injured in abdominal trauma. Historical management practices involved splenectomy, but more recent evidence suggests an increased risk of severe infections and sepsis associated with this approach. Accordingly, nonoperative management strategies, including prophylactic splenic artery embolization and clinical observation, have gained prominence. This systematic review with meta-analysis directly compared angioembolization with clinical observation for high-grade splenic injuries only, aiming to provide clarity on this matter amid ongoing debates and variations in clinical practice.

Inclusion criteria:
This review included adult patients aged 15 years or older with high-grade splenic injuries (grades 3–5) due to blunt trauma. Outcomes of interest include the need for further intervention (failure of management), mortality, complications, red blood cell transfusion requirements, hospital length of stay, and intensive care unit length of stay.

Methods:
A comprehensive search of PubMed, Embase, and CINAHL (EBSCOhost) was performed, with no restrictions on language or publication date. Gray literature was searched, including trial registries and relevant conference proceedings. After deduplication, 2 reviewers independently assessed titles and abstracts, and, subsequently, full-text articles for eligibility. Methodological quality of the included studies was assessed using standardized instruments from JBI. Data were extracted using predefined templates, and statistical meta-analysis was performed, where possible, using a random-effects model. Heterogeneity was assessed using statistical methods, and potential publication bias was tested with a funnel plot. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the certainty of evidence.

Results:
Sixteen studies were included in this review. Methodological quality assessment indicated some risk of bias in most studies, with concerns primarily related to differences in injury severity and potential confounding factors. Meta-analysis revealed that prophylactic angioembolization significantly reduced risk of management failure by 57% (OR 0.43, 95% CI 0.28–0.68, I
2=53%, 15 studies) and decreased patient mortality by 37% (OR 0.63, 95% CI 0.43–0.93, I
2=0%, 9 studies) compared with clinical observation alone. There was a 47% reduction in risk of complications associated with prophylactic embolization compared with clinical observation (OR 0.53, 95% CI 0.29–0.95, I
2=0%, 4 studies). Some statistical heterogeneity was observed, with I
2 ranging from 0% to 53%. No significant differences were observed between the 2 management strategies for red blood cell transfusion requirements or hospital length of stay.

Conclusions:
The results of this review support the use of prophylactic embolization for high-grade blunt trauma splenic injuries, indicated by lower rates of management failure, reduced need for additional interventions, lower mortality, and fewer complications.

Review registration:
PROSPERO CRD42023420220