Accuracy of a 3-dimensionally printed custom endoscopy port for minimally invasive ventral slot decompression in dogs: A cadaveric study

Objective: To evaluate the accuracy of a 3-dimensionally (3D)-printed custom endoscopy port (3DEP) for minimally invasive cervical ventral slot decompression. Study design: Cadaveric study. Animals: Fifteen cadavers of dogs weighing between 3.1 and 34.4 kg. Methods: Minimally invasive cervical ventral slots were created using a 3DEP and an endoscopic system at the C3-C4 intervertebral disc space in each dog by 1 experienced and 1 inexperienced surgeon. Postoperative computed tomography was performed to compare the planned and postoperative screw trajectories (angle, entry point, exit point, and length of the screw entering the spinal canal) and quantify slot formation dimensions. Results: Thirty screws were inserted in 30 vertebral bodies. Mean screw angle deviation was less than 2.5°, entry and exit point deviation was less than 1.6 mm, and length of the screw entering the spinal canal was less than 0.6 mm. No differences were identified between the experienced and inexperienced surgeons. Ventral slot length ratio was 30.15 ± 1.86 for the experienced surgeon and 29.38 ± 1.61 for the inexperienced surgeon (p =.372). The mean ventral slot width ratio was 45.60 ± 1.80 for the experienced surgeon and 47.20 ± 1.54 for the inexperienced surgeon (p =.261). Conclusion: Screw positioning and creation of ventral slots were accurately performed using the 3DEP by both inexperienced and experienced surgeons. Clinical significance: The use of a 3DEP for minimally invasive cervical ventral slot decompression may be an alternative to the conventional ventral slot in dogs. Additional studies are needed to evaluate efficacy and safety.