Study of postoperative laryngopharyngeal discomfort: protocol for a single-centre cohort study.

INTRODUCTION: Postoperative laryngopharyngeal discomfort after extubation can lead to severe throat pain, dysphagia, or postoperative tongue oedema. Possible mechanisms include increased oral pressure, obstruction of venous and lymphatic return in the neck, and increased capillary hydrostatic pressure, which leads to oedema of the tongue and upper airway. However, real-time monitoring indicators of anaesthesia are lacking. Therefore, we designed this study to accurately measure the contact force of the tracheal tube on the tongue in different surgical positions during general anaesthesia. METHODS AND ANALYSIS: This prospective single-centre observational study will enrol 54 patients undergoing elective surgery under general anaesthesia for>2 hours with endotracheal tube application from 1 July 2023 to 30 June 2024. Patients will be divided into the supine (Supine group) and high-risk (Flexion group) groups. Dynamic changes in the contact force between the tracheal tube and tongue will be measured using T-Scan technology. All patients will be followed up for 7 days postoperatively. The primary endpoint is postoperative laryngopharyngeal discomfort. Secondary outcomes include the time to the first successful recovery of oral intake of fluids and solid food, and airway-related events. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of Clinical Research of China-Japan Friendship Hospital (2023-KY-219, approved on 14 September 2023). Informed consent will be obtained during anaesthesia evaluation. This study aims to explore the characteristics of the contact force on the tongue caused by endotracheal intubation in different surgical positions and to provide a better understanding of the risk factors and prevention of postoperative laryngopharyngeal discomfort. The findings of this study will be presented at our hospital, reported on ClinicalTrials.gov, and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05987293.

Occipitocervical Revision Surgery Using the Bicortical Screw and Plate System for Failed Craniovertebral Junction Stabilization.

BACKGROUND: To evaluate the clinical efficacy and safety of the modified technique utilizing the occipital bicortical screws and plate system in occipitocervical revision surgery. METHODS: Between October 2010 and May 2018, 12 consecutive patients were retrospectively evaluated. All patients had posterior occipitocervical resurgery utilizing modified technique of bicortical screws and occipital plate. The measurements of extracranial occiput on midline were conducted on computed tomography (CT) scans. The thickness of the occipital bone at the location of external occipital protuberance and below 15 mm were evaluated, respectively. For the procedure, the trajectory was drilled perpendicular to the external occipital protuberance for the specified depth with a depth-limited drilling, 2 mm away from the internal bone plate, then the trajectory was deepened at intervals of 1 mm each time until reaching the internal bone plate. Meanwhile, a probe was used to explore all the walls of the trajectory. Bicortical screws were inserted to the occipital plate and the depth of penetration was less than 2 mm from the internal bone plate. Clinical efficacy and radiographic evaluation were followed up. RESULTS: The thickest point was the external occipital protuberance, which was 15.49 ± 1.47 mm and decreased gradually on the midline to 13.41 ± 1.60 mm at below 15 mm. Twelve cases (mean age 41.17 years; range, 24-62 years), including five males and seven females, were followed up for 24.08 months (14-32 months). The interval time was 40.42 months (3-156 months) after the initial operation. At the final follow-up, JOA score increased from 8.58 ± 2.53 before surgery to 12.67 ± 1.84 (P < 0.05) and VAS score improved from 6.17 ± 1.21 to 2.08 ± 1.32 (P < 0.05). Besides, clinical symptoms were relieved in all patients after revision surgery. All patients had rigid internal fixations with bone fusion and no major complications occurred. CONCLUSIONS: Posterior occipitocervical plate-screw system with bicortical screws had the advantages of safety, simple and promising efficacy without excessive tissue release or intraspinal manipulation, proving that it's valuable as a modified technique for occipitocervical revision surgery.

[Function of NOD-like receptor protein 1 inflammasome in traumatic central nervous system injury].

NOD-like receptor protein 1 (NLRP1) inflammasome plays an important role in the innate immune response of human body. It can promote the activation of cysteinyl aspartate specific proteinases(Caspases), further activate interleukin-18 and interleukin-1 ß, and mediate pyroptosis. NlRP1 inflammasome plays a role in traumatic central nervous system injury. In this study, the structure of NLRP1 inflammasome, the activation of NLRP1 inflammasome in traumatic central nervous system injury and the treatment with NLRP1 inflammasome as a target are reviewed.

Flexion Dysfunction of Atlanto-Occipital Joint Associated with Cervical Spondylosis.

OBJECTIVE: To investigate the association between atlanto-occipital radiographic alignment in flexion and cervical spondylosis (CS). METHODS: This is a retrospective case-control study. CS patients were recruited from our hospital, and the age/gender/body mass index (BMI)-matched healthy controls were selected from the subjects in health examinations at the same hospital between January 2015 and May 2019. A total of 464 subjects was included in the study. There are 282 males and 182 females. The ages of patients were 20 to 67 years, and the mean age was 33.9 years. CS patients were considered the case group. Based on surgical treatments, they were subdivided into non-operation group and operation group. The operation group and non-operation group had 45 and 187 patients, respectively, while 232 subjects were included in the control group. The angle between McGregor's line and C1 line (O-C1 angle) was evaluated on images taken in flexion (F-OC) and neutral positions (N-OC) independently. The relationship between the FOC (FOC=F-OC-N-OC) and Neck Disability Index (NDI) was examined, and the involvement of the FOC in the onset of CS was analyzed. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off for detecting an increased risk of CS. RESULTS: The median follow-up time was 51.6 months (25-115 months). The case groups, especially the operation group, tended to be older (55.8 ± 11.2 vs 41.6 ± 13.8 vs 23.5 ± 5.5 years, P < 0.001), have a higher NDI score (12.2 ± 4.5 vs 6.2 ± 2.1 vs 3.2 ± 1.2, P < 0.001), and longer medical history (10.5 ± 9.5 vs 6.8 ± 11.2 years, P < 0.001). One-way analysis of variance showed statistically significant differences in FOC between the control and case groups (1.4° ± 1.2° vs 3.6° ± 1.9° vs 7.2° ± 2.0°, P < 0.001). Besides, a post-hoc Tukey test showed a lower FOC in the operation group compared with that in the non-operation group (1.4° ± 1.2° vs 3.6° ± 1.9°, P < 0.001). Using FOC as a radiological predictive model to predict CS, the cut-off value was 4.2°. Using FOC as a radiological predictive model to predict CS, the area under the curve (AUC) was 0.86 (95% CI: 0.78-0.92, P < 0.001). In the univariable risk analysis model, conditional logistic regression showed that the FOC level was an independent factor with an important role in the risk of CS. The odds rose to 8.2 times when FOC reached the level under 4.2° (OR = 8.2; 95% CI: 6.4-10.0; P < 0.001). There existed a significant negative correlation between FOC levels and NDI (r = -0.451, P = 0.016). CONCLUSIONS: Stiff O-C1 , which is defined as FOC ≤ 4.2°, represented decreased flexion dysfunction of atlanto-occipital joint and is closely associated with high risk for the occurrence of CS. This finding could show a possible relationship between upper and lower cervical spine and help spine surgeons to understand the pathological process of CS and implement appropriate management.

[Pedicle exposure technique for atlas screw fixation:a radiological research].

OBJECTIVE: To investigate the meaning of pedicle exposure technique for screw fixation on atlas with the vertebral groove height less than 4 mm by using reconstructive computed tomography. METHODS: From April 2015 to June 2015, 84 pedicles of 51 patients with groove heights less than 4 mm were studied by digital reconstruction respectively. Parameters of atlas pedicle screw fixation were measured. RESULTS: Among the 51 cases, the vertebral groove height was (3.28±0.51) mm. Lateral mass heights, lateral mass widths and the transition area heights between lateral mass and posterior arch were fit for 3.5 mm screw implanting. Ideal pedicle screw trajectory lengths from 0° to 15° (0°, 5°, 10°, 15°) were (27.36±1.81), (27.01±1.68), (27.07±1.75), (27.48±1.72) mm, exposed trajectory lengths from 0° to 15°(0°, 5°, 10°, 15°) were(23.44±1.79), (23.87±1.84), (24.58±1.89), (25.56±2.01) mm, trajectory length of lateral mass was (20.78±2.05) mm. The mean CT values on 5 sections through pedicle trajectory and lateral mass trajectory were (701.89±141.48) HU and (599.11±137.33) HU, respectively. There were no significant differences between ideal pedicle trajectory lengths from 0° to 15°(P>0.05). Exposed trajectory lengths was significantly increased accompanying with medial angles increasing (P<0.05), and was longer than trajectory lengths of lateral mass (P<0.05). CT value of pedicle screws was higher than CT value of lateral mass screws significantly (P<0.01). CONCLUSIONS: Screws can be implanted in atlas with vertebral groove height less than 4 mm by using pedicle exposure technique. Few trajectory lengths will be sacrificed with favorable pull out strength due to adequate bone mass purchased.

[Surgical treatment for Forestier disease: a report of 8 cases].

OBJECTIVE: To investigate the clinical effects and operative options for the treatment of Forestier disease. METHODS: From June 2005 to May 2012, 8 patients with progressive dysphagia due to Forestier disease were treated through anterior approach, their clinical data were retrospective analyzed. There were 6 males and 2 females, aged from 65 to 83 years old with an average of 73 years. Among the patients, osteophytes removal was performed in 3 cases, osteophytes removal with discectomy and fusion was performed in 2 cases, osteophytes removal with corpectomy and fusion was performed in 3 cases. According to Bazaz dysphagia score to assess the improvement of the patients' symptoms before and after operation. RESULTS: All patients were followed up from 12 to 40 months with the mean of 18.5 months. Seven cases were asymptomatic and 1 case had mild symptom in the last follow-up. Radiographs showed the space enlargement between vertebral body and trachea. CONCLUSION: It is effective to treat patients with progressive dysphagia due to Forestier disease through surgical method. And the operative options depend on the stability of cervical spine and the neurological symptoms of the patients.