Modified stereotactic neurosurgery techniques for rodent surgery enhance survival and reduce surgery time in a severe traumatic brain injury model

Abstract

Controlled cortical impact (CCI) is the most widely used mechanical model of traumatic brain injury (TBI) in rodent brains. This neurosurgical procedure generally involves the use of a stereotaxic system, which requires reaching a specific brain region with the most accurate position possible. In this study, a modified stereotaxic system for TBI induction was developed to evaluate preclinical research in rodents for conducting neural stimulation experiments by using an implanted electrode to assist in rehabilitation after severe TBI. The proposed model aims to reduce animal mortality during surgery and alleviate the negative side effects potentially caused by prolonged anesthesia drug usage. Isoflurane is applied as an anesthetic drug before stereotaxic surgery in rodents, which promotes hypothermia in the animal body. The result showed notable improvement in rodent survival after applying an active warming pad system to prevent hypothermia. Compared with the conventional stereotaxic system, the modified CCI device with a mounted 3D-printed header significantly improved performance in the surgical procedure, decreasing the total operation time by 21.7%, especially in the Bregma‒Lambda measurement. These findings indicate the tangible capability of our modified stereotaxic system, which allows surgeons to perform stereotaxic surgery faster and lowers the risk of intraoperative mortality.

Keywords: Controlled cortical impact; Neurostimulation; Neurosurgery; Stereotaxic; Traumatic brain injury.

Fig. 1

A modified stereotaxic system. (a) The overview design of modified stereotaxic. (b) A 3D CAD model of a 3D-printed header. (c) A 3D CAD model of a CCI device mounted with a 3D-printed header. (d) A CCI device mounted with a 3D-printed header.

Fig. 2

An active warming pad system for thermal support during stereotaxic surgery. (a) The overview design of active warming bed system. (b) The active warming pad before heating. (c) The active warming system after heating with the PID controller.

Fig. 3

An active warming pad system enhances survival rate and operation time during stereotaxic surgery. (a) Survival rates following stereotaxic surgery without a warming system (n = 3) and with a modified stereotaxic system with an active warming system (n = 4). *p < 0.005. The data are presented as analyzed using McNemar’s test. (b) The operation times for stereotaxic surgery without a warming system (n = 3) and the modified stereotaxic system with an active warming system (n = 4). *p < 0.005; ns, not significant. The data are presented as the mean ± sd and were analyzed using two-tailed Student’s t tests.

Fig. 4

The modified stereotaxic system improves surgical duration upon CCI induction and electrode implantation. (a) Stereotaxic surgery for TBI induction using the CCI method and electrode implantation. (b) Surgical duration of the traditional stereotaxic system (n = 3) and modified stereotaxic system (n = 5) after CCI-induced TBI and electrode insertion in rodents. *p < 0.05. The data are presented as the mean ± sd and were analyzed using two-tailed Student’s t tests.

Fig. 5

Bregma‒Lambda positioning duration decreases during stereotaxic surgery procedure. Bregma‒Lambda measuring time of traditional stereotaxic system (n = 3) and modified stereotaxic system (n = 5). **p < 0.05; ns, not significant. The data are presented as the means ± sd and were analyzed using two-tailed Student’s t tests.