The Difference Of Electrical Impedance Among Tissues In The Anterior Approach Of The Cervical Spine

ObjectiveAnterior decompression is the most common surgical intervention for the treatment of cervical spondylosis,the risk of severe complications may from the vital organ cross linked approach of the surgery.Electrical impedance(EI)is helpful in discriminating tissue types;however,the EI of different tissues in the anterior approach of the cervical spine has not been reported yet.MethodThe experiments were performed on 12 animals which were all obtained from Tianjin Experimental Animal Center.The weights of 6 New Zealand white rabbits were 2.4 Kg,2.8 Kg,2.6 Kg,3.0 Kg,2.9 Kg and 2.7 Kg,respectively,mean2.7 Kg.The weight of 6 mini-pigs were 32 Kg,26 Kg,30 Kg,29 Kg,31 Kg,33 Kg,respectively,mean 30.2 Kg.Standard anterior approach of the cervical spine were performed on the animals under general anesthesia and the tissues across linked the approach were incised carefully.A probe was applied to detect the EI of 6 New Zealand white rabbits and 6 mini-pigs in vivo.The Esophagus(E),carotid artery(CA),tracheal cartilage(TC),annular ligaments of trachea(ALT),longus colli muscle(LCM),anterior longitudinal ligament(ALL)are classified as the prevertebral group;The cortical bone(CTB),cancellous bone(CCB),anulus fibrosus(AF),nucleus pulposus(NP)are classified as the vertebral group.Over the frequency range of 200 to 3000 kHz,the EI spectra of tissues were measured by a precision inductance-capacitance-resistance(LCR)meter and some individual values were excluded because of inconstant contact force,blood and poor contact between the probe and the tissue surface.Then the EI measurements were analyzed with Prism6 and IBM SPSS Statistics 22 through Kruskal-Wallis test.P values < 0.05 were considered statistically significant.Results1.in both rabbits and mini-pigs: The EI of all the vertebral group tissue pairs were significant difference at every investigated frequency.The EI of some prevertebral group tissue pairs also had significant difference at every investigated frequency.However,the EI between LCM and E,CA and ALT,TC and ALL had no significant difference at any frequency.2.in the rabbits,the EI between ALL and ALT had no significant difference at the frequencies of 2000 KHz to 3000 KHz;in the mini-pigs,it was the same for the EI between ALT and E,CA and ALL,LCM and ALT at the frequencies of 800 KHz to 3000 KHz,3000 KHz,3000 KHz,respectively.3.In both rabbits and mini-pigs,the EI measurements of different tissues during anterior approach of the cervical spine changed with frequency increasing and had the maximum modulus at the frequency of 200 KHz,the minimum modulus at the frequency of 3000 KHz.ConclusionWith certain frequencies,there are significant differences in EI among tissues in the cervical spine anterior approach.This result indicates the possibility of applying the EI for tissue discrimination in the anterior approach of the cervical spine.