RESUMO
OBJECTIVE: Chronic subdural hematoma (CSDH) is one of the most common types of intra-cranial hemorrhages usually associated with trauma. Surgical treatment is the treatment of choice and burr hole trephination (BHT) is widely performed. The recurrence rate in the patients with CSDH is 3.7-30%. This study investigated the risk factors associated with the recurrence of patients with CSDH who underwent BHT. METHODS: One hundred twenty-five patients with CSDH underwent BHT. Eight of 125 patients (6.4%) underwent reoperation for recurrent CSDH. We retrospectively analyzed demographic, clinical and radiological findings, catheter tip location and drainage duration as the risk factors for the recurrence of CSDH. RESULTS: Recurrence of CSDH in the high- or mixed-density groups was significantly higher than those in the low- or iso-density groups (p<0.001). Placement of catheter tip at the temporoparietal area was associated with a significantly higher recurrence rate of CSDH than placement at the frontal area (p=0.006) and the brain re-expansion rate (BRR) was much lower than placement at the frontal area (p<0.001). CONCLUSION: The operation may be delayed in high- and mixed-density groups, unless severe symptoms or signs are present. In addition, placing the catheter tip at the frontal area helps to reduce the incidence of postoperative recurrence of CSDH and to increase the BRR.