Role of the patient comorbidity in the recurrence of chronic subdural hematomas

Chronic subdural hematoma (CSDH) is an old blood collection between the cortical surface and the dura. Recurrence of CSDH after surgical evacuation occurs in up to a quarter of patients. The association between patient premorbid status and the rate of recurrence is not well known, and some previous results are contradictory. We aim to determine the impact of patient comorbidities in the risk of recurrence after surgical evacuation of CSDH. Retrospective data of a single institution's surgically evacuated CSDH cases followed up for at least 6 months were analyzed, and univariate and multivariate analyses were performed to identify the relationships between recurrence of CSDH and factors such as age, gender, CSDH thickness, neurological impairment at admission (NIHSS score), location of the CSDH (unilateral vs bilateral), Charlson Comorbidity Index (CCI), prothrombin time (PT), hemoglobin levels, and platelet count. A total of 90 patients (71 men and 19 women), aged 41-100 years (mean age, 76.4 ± 11.2 years), were included. CSDH recurred in 17 patients (18.9%). A higher CCI correlated with higher scores in the NIHSS. In the univariate analysis, recurrence was associated with a higher CCI (2.39 vs 1.22, p = 0.002), higher NIHSS scores (6.5 vs 4, p = 0.034), and lower PT levels (9.9 vs 13.4, p = 0.007). In multivariate analysis, only PT and CCI demonstrated to be independent risk factors for CSDH recurrence after surgical evacuation (p = 0.033 and p = 0.024, respectively). Patients with more comorbidities have a higher risk of developing recurrent CSDH. CCI provides a simple way of predicting recurrence in patients with CSDH and should be incorporated into decision-making processes, when counseling patients.