Comparison of an Electrical Cranial Access Drill with Autostop Technology to a Traditional Hand Crank Cranial Access Drill

Introduction: Craniostomies performed at bedside are one of the most important procedures in neurosurgery allowing for cranial access for monitoring of intracranial pressure, evacuation of subdural or epidural hematomas, or the placement of external ventricular drains. While neurosurgery as a whole has seen rapid advances in its technology, craniostomies continue to be performed with hand crank drill technology similar to what was used in the 1600s. The purpose of this study was to compare the efficacy and safety profile of a novel electrical cranial access drill with autostop technology (ECAD) to that of traditional hand crank drills.

Methods: Using both drills, holes were drilled into the cranial vault of human cadavers by a veteran cranial surgeon and by a medical student without prior experience in the procedure. Time to drill each hole and the number of dural violations was compared between drills. Prices for each drill type were recorded from institutional prices. For comparison purposes, the cost of the cranial access kit was assumed to be equal.

Results: Overall, 30 craniostomies were created with the hand crank drill and 61 were created with the ECAD. The average time to hole competition was significantly longer with the hand crank drill than with the ECAD (24.1 v. 16.5 sec, p=0.00018). There were significantly more dural violations with the hand crank drill than with the ECAD (13 v. 2, p=0.002), which engaged autostop in 100% of procedures. The difference between costs and medicare reimbursement was as follows: hand twist drill +$103; electric drill without autostop +$2; electric drill with autostop -$52.

Conclusion : The electric drill with autostop technology demonstrated faster time to hole completion and significantly fewer dural violations than the traditional hand crank drill. Due to a lack of data on “plunge” rates of cranial access drills it is unclear whether the benefit of the safety features on newer drills is worth the additional costs. Additional studies comparing the efficacy of different types of drills across large populations are needed.