Objective      To compare the therapeutic effect of one burr-hole craniotomy

two burr-hole craniotomy

and small craniotomy for chronic subdural hematoma (CSDH).        Methods      Clinical data about 125 CSDH patients who underwent operation in our hospital from October 2005 to December 2010 were retro-spectively analyzed. The patients were divided into one burr-hole craniotomy group (group A

n=31) with the burr hole size of about 10 mm in diameter

two burr-hole craniotomy (group B

n=50) with the burr hole size of about 10 mm in diameter

and small craniotomy group (group C

n=44) with the burr hole size of 20-30 mm according to their surgical procedure.        Results      No significant difference was found in residual hematomas in 7 d after operation and in neural function at discharge among the 3 groups (P0.05). The operation time was significantly shorter in group A than in groups B and C (P0.05). No significant difference was observed in hospital stay time (day) and incidence of inflammation between group A and group B (P0.05). However

the hospital stay time (day) was significantly longer and the incidence of inflammation was significantly higher in groups A and B than in group C (P0.05). The incidence of relapse was significantly higher in group A than in groups B and C (P0.05) with no significant difference between groups B and C (P0.05). Multivariate regression analysis showed that the surgical procedure was an independent factor for relapse after operation while the incidence of relapse was significantly lower after one burr-hole craniotomy than after two burr-hole craniotomy (OR=0.148

95%CI=0.026-0.847

P=0.032).       Conclusion      Small craniotomy is the first choice of surgical procedure for CSDH while two burr-hole craniotomy can reduce the incidence of relapse

especially in patients after operation.