Application of Augmented Reality Neuronavigation in Transnasal Endoscopic Skull Base Surgery

1\. Research protocol The surgical AR neuroendoscopic system in this study mainly includes three core links: (1) virtual image or environmental modeling. AR systems use data derived from color or texture differences between anatomical structures in CT or MRI tomography, as well as whole-brain angiography, to complete a 3D reconstruction of a subsurface target in a computer. This process can also be done manually using the 3D-Slicer software. (2) Registration of virtual environment and real space. Registration technology is essential for AR systems, as it enables real-time tracking of anatomical structures in the endoscopic field of view. Registration can be done by a variety of means, such as the 3D Cartesian system, which is based on framing technology, which can determine the position and attitude of the imaging device, while also allowing the virtual environment to make rapid changes and register when the position changes in the real world. Or use frameless registration to register virtual match points with known anatomical landmarks in real space. (3) The final demand is to combine the virtual environment with the real environment to display technology. It can be divided into head-mounted display (HMD), enhanced external display, enhanced optical system, enhanced window display and image projection. Using HMDs to overlay virtual environments with video feeds from real environments (video perspective). Utilize a simple, stand-alone screen as an enhanced display to display virtual content on a video originating from a neuroendoscope.

After the above links are successfully achieved, transnasal skull base surgery is performed using neuroendoscope with AR to achieve real-time tracking, accurately identify anatomical structures, and reduce the risk of neurovascular injury and complications in skull base surgery.

Subjects: About 100 cases of neuroendoscopic skull base surgery performed in the Department of Neurosurgery of the First Affiliated Hospital of Xiamen University, regardless of gender and age.

Inclusion Criteria: 1. Patients undergoing transnasal endoscopic skull base surgery in our department. 2. Thin-slice head MRI and CTA scans were performed before surgery. Exclusion Criteria: 1. Patients without clear preoperative imaging data. 2. Patients who do not agree to receive AR fusion neuroendoscopic assistance. 3. Patients with incomplete medical records.

Intervention: Participants were divided into two groups to undergo transnasal skull base surgery using common neuroendoscopy and neuroendoscopy infused with augmented reality technology and compared.

Evaluation methods: The surgical effect was evaluated according to the patient's tumor size, pathological type, operation time, length of hospital stay, complications, and whether there was a history of pituitary surgery.

Effectiveness evaluation indicators (primary efficacy index and secondary efficacy index):

The main efficacy indicators: duration of surgery, whether the augmented reality navigation was successfully established during the operation, whether the augmented reality navigation was accurate during the operation, the incidence of cerebrospinal fluid leakage during the operation, and the incidence of damage to important anatomical structures during the operation Secondary efficacy measures: endocrine improvement rate, visual field improvement rate, length of hospital stay, etc.

Statistical methods: Chi-square test was used for counting data, t-test was used for measurement data, and SPSS software was used for data processing.

Participant participation time: one year after the patient is admitted to the hospital to be discharged.

Location: The First Affiliated Hospital of Xiamen University Hypothesis: Neuroendoscopy integrated with augmented reality technology can greatly promote intraoperative orientation and facilitate the surgeon's observation of correlation anatomy. Therefore, we hypothesize that neuroendoscopy with augmented reality technology can reduce surgical complications and improve surgical efficacy compared with traditional endoscopy.

All eligible subjects were randomly divided into two groups to undergo traditional nasal endoscopic surgery and endoscopic transnasal surgery with augmented reality technology, and relevant data were collected for statistical analysis after the surgery. None of the subjects were grouped before surgery. Traditional transnasal endoscopic surgery was used as the control group to evaluate the therapeutic effect of augmented reality endoscopy. Before the study was carried out, the research group had a comprehensive grasp of the factors such as the size of the cases requiring nasal surgery and the age and gender composition of the patients who needed to undergo nasal surgery in our hospital, established a good sampling framework, and strictly implemented stratified and proportional sampling, so as to avoid and reduce selective bias. The research team has done a good job of coordination and mobilization before the investigation, obtained the cooperation of the department and the relevant departments of the outpatient department, established a trust relationship with the patients, reduced the refusal of visits, thereby reducing the selectivity bias, and can improve the authenticity of the interviews and reduce the bias of information. Avoid and reduce refusals as much as possible. This study followed ethical principles throughout the process, obtained the trust and cooperation of patients, and avoided and reduced information bias. Responsible and communicative team members were selected as investigators to reduce information bias.

The duration of this study was from the time the patient was admitted to the hospital and the patient was discharged 1 month later, with an average of about 1 month. The follow-up time was 1 month, 3 months, 6 months and 1 year after surgery, respectively.

The main intervention method in this study was to use a neuroendoscope developed by the research group integrating augmented reality technology instead of traditional neuroendoscopy for transnasal skull base surgery.

Study endpoint: The study endpoint is reached if the study subject completes all phases of the study and follow-up according to the study protocol or withdraws the informed consent.

Sample size: A total of 100 cases of AR fusion neuroendoscopic transnasal skull base lesion surgery were completed in 3 years. The expected loss-to-follow/drop-out rate is less than 5%.

Study intervention: Transnasal skull base surgery using an augmented reality neuroendoscope developed by the research group instead of a traditional endoscope, which utilizes the hospital's existing Medtronic S7 navigation and Carl STORZ endoscope, and the safety of the above devices has been validated. The surgical instruments used to complete all cases are the same model of the same brand and the same operator, so as to avoid affecting the surgical process due to hardware reasons and manual operation. For each completed operation, the patient's relevant imaging information will be backed up, and the patient's case number will be recorded to prevent the loss of case information. The registration of intraoperative endoscope and AR was in accordance with the operating procedures, and after the registration was completed, the body surface markers were used to ensure the authenticity and accuracy of intraoperative AR images. At the time of discharge, all cases were informed of regular outpatient re-examination and postoperative follow-up. The case data is summarized once a month, and a special person is responsible for keeping the summary. The research team is cooperating and has rich experience in surgery. We have a professional operating room team to ensure the smooth progress of the operation. AR navigation may cause errors during the registration process, which should be operated in strict accordance with the navigation operation procedure, and in vitro navigation tests using body surface landmarks to reduce errors before performing surgery, and iCT registration should be used if necessary. In all cases, 4 CT scans of the head, 2 CT scans of the chest, 3 sMRI scans of the brain, 4 blood draws, and 1 bedside electrocardiogram were planned. If necessary, routine preoperative examinations such as color ultrasound and Holter electrocardiogram are performed. All surgical instruments are sterilized and packaged by the Supply Room of the First Affiliated Hospital of Xiamen University. All surgical equipment All of them are stored in a cool and dry place in the operating room of the First Affiliated Hospital of Xiamen University, and are adjusted and regularly maintained by professional engineers. The use of neuroendoscopy, neuronavigation and other devices is in accordance with the instructions and guidelines.

Measures to reduce bias: data and data collection should be as precise and precise as possible, and appropriate statistical methods should be selected.

Follow-up and compliance: A total of 4 follow-up visits were performed at 1 month, 3 months, 6 months and 1 year after surgery. During the follow-up, CT/MRI of the head was taken, blood tests were taken, and endocrine functions such as thyroid and pituitary gland were checked. By establishing a relationship of trust with patients in advance, improving service attitude, optimizing the treatment process, strengthening preoperative and postoperative guidance, and reminding patients to review in a timely manner, patients can improve their compliance.

Study Intervention Commitment:

Using the existing Medtronic S7 navigation and Carl STORZ endoscope to develop AR technology, the use of all equipment follows the instructions and guidelines, and the whole process of the operation is videotaped, and the postoperative review is carried out by a special person to ensure the smooth implementation of the surgical process, all the doctor's orders and medications during the patient's stay in the hospital are supervised by a special person, and the influence of medical drugs and operations on the surgical results is excluded. Medical records and other medical documents are kept by the research team, and the patient review reminder and follow-up are carried out by the special person.

Suspension of study intervention: If a large number of the following serious adverse reactions occur during the course of the study, the trial will be discontinued after the comprehensive decision of the investigator. (1) Severe cerebrospinal fluid rhinorrhea complications (2) Symptoms of periorbital bruising and hematoma in the eye, or severe vision loss, blurred vision and other manifestations. (3) Severe nasal bleeding, causing anemia or even shock, or nasal adhesions, which seriously affects nasal ventilation and sinus drainage. (4) Damage to large blood vessels and nerves, (5) Severe symptoms of endocrine disorders, (6) Severe cerebral edema or intracranial infection During the study interruption: carefully check the software and hardware problems of the endoscopy system, check the accuracy of the image output, and test the effectiveness of the software. Check whether there are any problems with the surgical conditions, surgical instruments and surgical team. and provide effective medical assistance to subjects who have adverse events. The relevant information of all subjects with adverse events was collected, including but not limited to: age, gender, time of consultation, image number, diagnosis, visual field, endocrine status, operation time, whether there was cavernous sinus hemorrhage during the operation, whether the tumor was completely resected, whether there was cerebrospinal fluid leakage, whether the augmented reality navigation was successfully established during the operation, whether the augmented reality navigation was accurate during the operation, the length of hospital stay, the postoperative visual field, and the endocrine situation.

Withdraw/Withdraw from the Stu