Evaluation of a novel high speed burr tip for safe and efficient bone surgery in a sheep model

Abstract

The exposure of neural structures by removing the overlying bone using a high-speed drill can cause iatrogenic injury to the dura, neural tissue, and vessels. We investigated the safety and efficacy of a novel Surgify Safety Burr (SSB), attachable to existing high-speed drills. Three anesthetized living sheep underwent cranial burr hole drilling (n = 19) and hemilaminectomies (n = 14) with the SSB and standard burrs. Drilling time, dural injury, and subjective evaluation of heating and haptic feedback of each burr were assessed. Cranial burr hole drilling was done using diamond (n = 3), fluted (n = 6), and SSB (n = 10) burrs. Penetrating dura damage was observed in 33% of the diamond burr drilled holes, and in 33% of the fluted burr drilled holes, but not in the holes drilled with the SSB. Hemilaminectomies were performed with the SSB (n = 7) and diamond (n = 7) burrs without drilling-induced dura damage. Mean drilling time was not significantly different in cranial drilling (SSB, 121 ± 18s; fluted burr, 63 ± 22s; diamond burr, 165 ± 29s) nor in hemilaminectomy (SSB, 108 ± 13s; diamond burr, 95 ± 18s). Subjective evaluation of the SSB suggested efficient bone removal without heating or chattering. The SSB is a safe and effective surgical tool in cranial drilling and hemilaminectomy procedures. Safety, efficacy, and clinical benefits should be established in human studies.

Keywords: Burr; Dural tear; High-speed drill; New technology; Soft tissue injury; Surgical instrument.

Fig. 1

(A) The Surgify Safety Burr (SSB), including a (B) description showing the parts and differential modes in bone cutting and soft tissue protection mode, and (C) a detailed scheme of the different positions of the moving ring where the tool is not in contact with hard tissue/bone (left), and when it is pressed against soft tissue (right). The length of the burr shaft is 85 mm (medium version) and 140 mm (long version) and the diameter of the burr head is 5.4 mm.

Fig. 2

Cranial burr holes from sheep. Tears are referred by the following symbols: X: penetrating dura lesion with high-speed burr; X_m: penetrating mucosa lesion with high speed burr; x: superficial dura lesion with high speed burr; k: dura lesion with Kerrison punch. Holes were drilled with (a) the SSB (1, 3, 6, 7, 10, 12, 13, 16, 17, and 19); (b) the fluted burr (4, 9, 11, 14, 15, and 18); and (c) the diamond burr (2, 5, and 8).