Obtaining the olfactory bulb as a source of olfactory ensheathing cells with the use of minimally invasive neuroendoscopy-assisted supraorbital keyhole approach—cadaveric feasibility study

Abstract

Background. Obtaining the human olfactory bulb (OB) for treatment of spinal cord injuries with olfactory ensheathing cells (OECs) requires the elaboration of a surgical approach that could meet the criteria of safety and minimal invasiveness. The aim of the study was to evaluate the suitability of the keyhole supraorbital craniotomy (SOC) with an eyebrow incision for obtaining OB for therapeutic purposes. Methods. Seventeen SOCs were performed on nine fresh adult cadavers. The procedure of obtaining OB was conducted by neuroendoscope-assisted microsurgical dissection. Technical features related to the procedure were measured and adverse events were noted. The virtual three-dimensional planning was applied in six cases to verify the authorial A–C scale published previously. Results. The intact OB was obtained in 10 (59%) cases and a minor injury was discovered in another 5 (29%) cases. In 2 (12%) specimens OB was severely damaged which was correlated with the minor neural tissue injury (Fi2 = 0.44). While no case of an evident vascular injury was noted, there were 3 (18%) incidents of unintended frontal sinus opening positively correlated with the craniotomy width (Fi2 = 0.44). The unfavorable three-dimensional (3D) configuration of the olfactory groove area was revealed in 66% of cases and highly correlated with OB injury (Fi2 = 1.0) but not damage. Conclusions. The SOC via an eyebrow incision may be safely and effectively applied to obtain the OB as a source of OECs in roughly 90% of cases. Virtual 3D planning is useful in preoperative qualification of potential donors.