Figure 3

Surgical workflow (A–H) and results (I–K) from cadaveric pre-clinical study. (A) Specimen positioning for EVD catheter implantation. (B) The EVD key and localizer were mounted on the specimen and (C) a pre-procedure CT scan was obtained. (D) The CT data was transferred to surgical planning software and fiducial registration was performed. Stereotactic coordinates were obtained for a target close to the foramen of Monro and an appropriate trajectory (collar and arc angles) was chosen. (E) The stereotactic coordinates, and the arc and collar values obtained in the previous step were dialed into the stereotactic targeting device and the device was mounted on the EVD key. (F) A probe was used to mark the site of incision along the trajectory. (G) An incision was made at the marked site and a 5 mm burr hole was stereotactically drilled into the bone with the help of a drill guide and a standard #9 drill bit. (H) A metal catheter was then implanted into the brain and secured in place. A post-procedure CT scan and target verification was performed thereafter (not shown). (I) A schematic explaining the 3D Euclidean error and trajectory error. (J) The 3D Euclidean error and targeting error were found to be 1.8 ± 0.6 mm (n = 10) and 1.9 ± 0.8 mm (n = 10) (K) Stepwise and total procedure time: key placement (1.6 ± 0.4 min, n = 4), surgical planning (9.4 ± 3.5 min, n = 10), EVD catheter implantation (14.7 ± 2.6 min, n = 8) were completed in total 26.5 ± 3.1 min (n = 8).