Ravina Kristine, Yang Natalia, Brocoum Sophia, Pasco-Anderson Julia, Walker Robert L, Khan Marina, Cabodi Mario, Holsapple James
1Department of Neurosurgery, Boston Medical Center, Boston, Massachusetts.
2Section of Neurosurgery, Carilion Clinic, Virginia Tech Carilion School of Medicine, Roanoke, Virginia; and.
J Neurosurg. 2023 Feb 10;139(3):881-891. doi: 10.3171/2022.12.JNS221719. Print 2023 Sep 1.
Despite external ventricular drain (EVD) procedures being commonplace in neurosurgical practice, suboptimal placement rates remain high, and complications are not uncommon. The angle of the EVD catheter insertion and the accuracy of the drill hole placement are major factors determining successful EVD placement that are dependent on the drill bit morphology. The standard cylindrical 2-fluted twist drill bit creates a relatively deep and narrow drill hole that requires precise positioning, has limited visibility of the drill hole bottom and restricted catheter angular adjustment range, and poses the risk of inadvertent dural puncture. To overcome the standard problems associated with EVD drill bit morphology, the authors propose novel cone-shaped drill bits for EVD placement.
Conical drill bits of 30° and 45° were designed, manufactured, and tested in a simulated laboratory setting as well as in three human cadavers with intact skull, dura mater, and brain. Drill bit performance was rated by neurosurgical trainees across various domains using Likert scale-type questions.
In the laboratory, maximum drilling temperatures adjacent to the drill hole were recorded and compared for the standard drill bit and the 30° and 45° conical drill bits and were not significantly different (p = 0.631 and p = 0.326, respectively). The maximum temperature recorded directly underneath the drilling site for the 45° drill bit was significantly higher than the temperature of the standard drill bit (p = 0.043). The differences between the standard and 30° drill bits were not significant (p = 0.783). Upon cadaver testing, the drilling times with 30° and 45° conical drill bits were significantly longer than those with the standard drill bit (p = 0.036 and p = 0.002, respectively). Likert scale scores were significantly higher for the conical 30° (median [IQR] 4.7 [3.3-5]) and 45° (4 [2-5]) drill bits than for the standard drill bit (1.7 [1-2.5], p < 0.0001), indicating significantly better performance. Conical drill bits used as a "rescue" strategy allowed for an EVD catheter angular adjustment range 6 to 9 times greater than that for the standard drill bit and resulted in a zero inadvertent dural puncture rate.
The 30° conical drill bit can be safely used on its own or as a rescue tool to potentially achieve improved confidence, visualization, targeting, and precision of EVD placement while essentially eliminating the possibility of unintentional dural puncture with minimal increase in the total procedure time.
尽管脑室引流管（EVD）置入术在神经外科手术中很常见，但放置效果欠佳的比例仍然很高，并发症也并不罕见。EVD导管插入角度和钻孔位置的准确性是决定EVD成功置入的主要因素，这取决于钻头的形态。标准的圆柱形双槽麻花钻头钻出的钻孔相对深且窄，需要精确的定位，钻孔底部的可视性有限，导管角度调整范围受限，并且存在意外刺破硬脑膜的风险。为克服与EVD钻头形态相关的标准问题，作者提出用于EVD置入的新型锥形钻头。
设计、制造了30°和45°的锥形钻头，并在模拟实验室环境以及三个颅骨、硬脑膜和脑完整的人体尸体上进行测试。神经外科实习生使用李克特量表类型的问题对钻头在各个方面的性能进行评分。
在实验室中，记录并比较了标准钻头以及30°和45°锥形钻头钻孔附近的最高钻孔温度，两者无显著差异（p分别为0.631和0.326）。45°钻头钻孔部位正下方记录的最高温度显著高于标准钻头的温度（p = 0.043）。标准钻头和30°钻头之间的差异不显著（p = 0.783）。在尸体测试中，30°和45°锥形钻头的钻孔时间显著长于标准钻头（p分别为0.036和0.002）。30°（中位数[四分位距]4.7[3.3 - 5]）和45°（4[2 - 5]）锥形钻头的李克特量表评分显著高于标准钻头（1.7[1 - 2.5]，p < 0.0001），表明性能明显更好。用作“补救”策略的锥形钻头使EVD导管角度调整范围比标准钻头大6至9倍，且意外硬脑膜穿刺率为零。
30°锥形钻头可单独安全使用或用作补救工具，可能提高EVD置入的信心、可视性、靶向性和精确性，同时基本消除意外硬脑膜穿刺的可能性，且总手术时间增加极少。
