An improved electronic twist-drill craniostomy procedure with post-operative urokinase instillation in treating chronic subdural hematoma

• The current study has provided early experience for applying an improved electronic TDC technology in clinical practice.
• Choosing entry point at 0.5 cm anterior to coronal suture has multiple advantages.
• Post-operative urokinase instillation could shorten drainage time and decrease recurrence rate.

ObjectiveTwist-drill craniostomy (TDC) with closed-system drainage is a less invasive surgical technique for the treatment of chronic subdural hematoma (CSDH), but results in a higher disease recurrence rate. Therefore, we aimed to modify the TDC procedure in order to reduce the recurrence rate and further decrease complications.MethodsWe retrospectively reviewed 230 cases of standard CSDH in 202 patients treated in our hospital between January 2006 and December 2013. We employed a new TDC device called micro-steel-needle-tube-bit for puncture and drainage. We chose an entry point 0.5 cm anterior to the coronal suture at the superior temporal line and maintained post-operative drainage with urokinase instillation into the hematoma cavity. Clinical performance was assessed and compared by the Markwalder Grading Scale (MGS) score during the pre-operative period and at discharge. Recurrence of CSDH and complications were also recorded.ResultsMean operation time was only 8.9 (6–13) min. Mean catheter indwelling duration and hospital stay were 1.18 (271/230, 1–3) and 2.27 (458/202, 2–9) days, respectively. The average frequency of urokinase instillation was 1.14 (262/230, 1–3) times. Intracerebral and sub-arachnoid hemorrhages were found in one patient, but were not in the puncture pathway. No perioperative deaths occurred. Recurrence was observed in only one patient at 28 days post-operation. Among 202 patients, 193 (95.54%) showed improved clinical symptoms and neurological function, and significantly lower MGS scores at discharge than pre-operation (0.13 ± 0.45 vs. 1.37 ± 0.55, P < 0.01).ConclusionIn conclusion, electric TDC with micro-steel-needle-tube-bit at the pre-coronal suture entry point might be a safer, simpler, and faster mini-invasive surgical procedure for CSDH treatment. Post-operative drainage with instillation of urokinase could dramatically shorten drainage time and decrease recurrence rate.