A systemic review and meta-analysis on the impact of perioperative antiplatelets and anticoagulants on the clinical course of chronic subdural hematoma
Background: Chronic subdural hematoma is one of the most common conditions related to neurosurgical practice in the elderly. Reports about recurrence of patients on antiplatelets and/or anticoagulants are highly contradictory. Little current data exists regarding the outcome of chronic subdural hematoma patients on peri-operative medication related coagulopathy. We aimed to review the literature for studies about these drugs and outcome in chronic subdural hematoma patients.
Objectives: to perform a systematic review and meta-analysis of studies that examines the impact of antiplatelets and anticoagulants on the clinical evolution of chronic subdural hematoma.
Methods: We searched the Cochrane Library, PubMed, Scirus, MEDLINE, EMBASE, and the American Association of Neurological Surgeons (AANS) Database, and the conference proceedings of the European Association of Neurosurgical Societies (EANS). We also checked the reference lists of all retrieved studies and Controlled Trials metaRegister to identify any further studies. We searched the Internet using Google Scholar. We also contacted experts in the field as well as authors of the included studies. Searching was not restricted by date, language or publication status.
Selection criteria: Prospective and/or retrospective studies that examine the effect of anticoagulant and antiplatelet drugs on the clinical course of chronic subdural hematoma. Data collection and analysis: The author was the main data collector and investigator from the identified studies. The data needed extracted for analysis. We collected data related to the outcome of subdural hematoma and anticoagulation drugs from the included studies. Two reviewers independently checked the eligibility, study selection, methodological quality, risk of bias and extracted data. They also independently assessed the risk of bias assessments for the included studies according to the Cochrane Handbook for Systematic Reviews of Interventions. The authors of the study were contacted for missing information when possible. We pooled results of clinically and statistically homogeneous studies, where possible, to provide estimates of the effect of antiplatelets and anticoagulants. Then, we undertook separate subgroup analyses and meta-analysis for recurrent subdural hematoma only. We also calculated the risk ratios (RR) with 95% confidence intervals (CI). Any disagreements were managed by consensus after discussion among the author, the independent reviewers and the supervisors.
Main results: no randomised controlled trials were identified. We included eleven clinical cohort studies involving 1854 and 365 participants for the recurrent and bilateral categories, respectively. There was a significant increase in the risk of antipalatelets, with a pooled relative risk of 1.88. However, the pooled relative risk of anticoagulants was only 1.26 and it was not statistically significant.
Authors’ conclusions: formal recommendations can be made about the proper use and regular follow up of antiplatelets in patients. Anticoagulants do not significantly affect recurrent chronic subdural hematoma. Non-controlled studies usually come up with conflicting results. Therefore, further work is required in order to establish any potential effect of the new and old anticoagulation medications on the clinical course of chronic subdural hematoma. There is a need for well designed randomised controlled trials and prospective studies with large sample sizes and stratification of the different types of anticoagulation drugs investigating the role of antiplatelets and anticoagulants on chronic subdural hematoma.