Meta-Analysis of Functional Outcomes in 5508 Patients Sustaining a Gunshot Wound to the Head

Abstract

Abstract INTRODUCTION There is currently no consensus regarding prognosis and management for gunshot wounds to the head (GSWH). To the author’' knowledge, this is the first meta-analysis to study functional outcomes in GSWH. METHODS Five online databases and the reference lists of relevant articles were queried for cohort studies of GSWH reporting factors associated with functional outcome. PRISMA guidelines were followed. Study quality was assessed using the Newcastle–Ottawa scale. Glasgow Outcome Scale (GOS) outcomes were divided into unfavorable (GOS 1-3) and favorable (GOS 4-5). Pooled estimates of odds ratios and 95% confidence intervals were derived using random-effects models. Heterogeneity was assessed with I-square and meta-regression. Funnel-plots were utilized to assess publication bias. RESULTS We identified 35 retrospective cohort studies encompassing 5508 GSWH patients. Out of the factors assessed, the ones significantly associated with unfavorable functional outcome were: postresuscitation GCS 3 to 8 (Odds Ratio 33.2, 95% Confidence Interval [10.1-108.6]), suicide attempt (3.6 [1.7-7.8]), penetration of the dura (10.3 [1.8-60.5]), bullet trajectory through both hemispheres (8.3 [4.1-17.2]), through the ventricles (8.8 [1.6-48.8]), and through multiple lobes (8.6 [2.2-33.5]). No statistical significance was found for unfavorable functional outcome regarding patient age, sex, pupillary response, and the existence of an exit wound. CONCLUSION This is the first systematic review and meta-analysis regarding prognostic factors for neurologic outcomes in patients sustaining GSWH. Such factors can inform clinical decision-making and assist in setting patient and physician expectations in the acute setting. Further research is required to properly incorporate this information into management guidelines.