Postoperative Radiological Changes in Chronic Subdural Hematoma and Its Relation to Recurrence.

Kwon, Hyon Jo; Youm, Jin Young; Kim, Seon Hwan; Koh, Hyeon Song; Song, Shi Hun; Kim, Youn

Original Article

Journal of Korean Neurosurgical Society 2004;35(4): 410-414.

Hyon Jo Kwon, Jin Young Youm, Seon Hwan Kim, Hyeon Song Koh, Shi Hun Song, Youn Kim

Department of Neurosurgery, College of Medicine, Chungnam National University, Daejeon, Korea. jyyoum@hanbat.cnu.ac.kr

ABSTRACT

OBJECTIVE
The authors analyzed the postoperative radiological changes in chronic subdural hematoma (CSDH) after operation and its relation to the recurrence. METHODS: After reviewing the postoperative imagings of CSDH patients (90 cases, 70 patients), we classified them into 4 types according to the radiological changes in the hematoma area and calculated the prevalence of recurrence respectively. We also reviewed the preoperative images of the same patients and classified them into 4 types according to hematoma density and internal structure and investigated the prevalence of recurrence after operation respectively.
RESULTS
The low density area in postoperative computerized tomography (CT) showed the same Hounsfield unit and signal intensity in magnetic resonance imaging (MRI) with the CSF in ventricles. The recurrence of CSDH was lower if the hematoma was totally replaced with CSF (Type III) or the brain re-expanded completely with total hematoma drainage (Type IV) on postoperative imagings (p<0.05). The location of catheter tip can be used as a valuable indicator of the boundary of newly collected CSF and residual hematoma.
CONCLUSION
The low-density area found on postoperative CT medial to the residual hematoma in CSDH is filled with CSF and it can be a helpful factor in reducing the recurrence. The catheter tip location can be used as a good index and we can remove the catheter immediately after confirming the tip location on the inner surface of the skull.

Key Words: Chronic subdural hematoma; Catheter tip; Recurrence; Density