Endoscopic transoral approach nasopharyngectomy for petroclival and jugular foramen nasopharyngeal carcinoma / 中华耳鼻咽喉头颈外科杂志

Objective: To describe a technique of endoscopic transoral approach nasopharyngectomy for petroclival and jugular foramen nasopharyngeal carcinoma, based on anatomic studies and surgeries. Methods: Three dry human skulls and five fresh human cadaver heads were used for anatomic study of a endoscopic transoral approach to expose petroclival and jugular foramen. The anatomical landmarks and the extent of exposure were recorded. Six clinical cases who were treated in Eye & ENT Hospital, Fudan University from June 2020 to April 2022 were used to illustrate the technique and feasibility of this approach and to assess its indications and advantages, including 3 males and 3 females, aged 42 to 69 years old. Descriptive analysis was used in this research. Results: On the basis of the preservation of the internal pterygoid muscle and the external pterygoid muscle, this approach could fully expose the parapharyngeal, petrosal and paraclival segment internal carotid arteries, and safely deal with the lesions of jugular foramen and petroclival region. The 6 patients in our study tolerated the procedure well. Postoperative enhanced MRI showed complete resection of the tumor and no postoperative masticatory dysfunction. Conclusion: Endoscopic transoral approach is a safe, minimally invasive and effective surgical treatment for petroclival and jugular foramen recurrent nasopharyngeal carcinoma.

The endoscopic transnasal approach in management of the sinonasal tumor invading the anterior skull base / 中华耳鼻咽喉头颈外科杂志

Objective: To evaluate the feasibility of the endoscopic transnasal approach (ETA) and to analyze the outcomes and factors of this surgical technique in the management of the tumor invading the anterior skull base. Methods: A retrospective analysis was performed on 42 patients (31 males and 11 females, with mean age of 49 years) with sinonasal tumor invading the anterior skull base, who underwent ETA from June 2015 to April 2019 in Eye, Ear, Nose and Throat Hospital of Fudan University. Pathologically, there were 15 cases of squamous carcinoma (14 patients with T4bN0M0 and 1 patient with T4bN1M0) and 27 of olfactory neuroblastomas with Kadish stage C. Anterior skull base reconstruction was performed using the vascular pedicled nasoseptal mucoperiosteal flap and fascia lata. Brain non-contrast-enhanced CT was performed on the first postoperative day to exclude massive pneumocephalus, relevant brain edema and subarachnoid hemorrhage. Sinonasal contrast-enhanced MR was performed to assess the extent of the tumor removal. Kaplan-Meier analysis was used to calculate the overall survival (OS) and Cox multivariate regression analysis was used to determine the prognostic factors. Results: The mean duration of the surgery was 452 minutes. Total resection was performed in 36 patients (85.7%), subtotal resection in 2 patients (4.8%) with orbital involvement, partial resection in one patient (2.4%) with injury of the internal carotid artery. One patient (2.4%) underwent the second resection because of the tumor residual, two patients (4.8%) with unsure tumor residual. Mean follow-up was 20 months, with 17 months of median follow-up. One-, two-and three-year overall survival was 86.5%, 76.9% and 64.5%, respectively. For squamous carcinoma, one-, two-and three-year overall survival was 86.2%, 86.2% and 57.4%, respectively. For olfactory neuroblastomas, One-, two-and three-year overall survival was 86.9%, 75.3% and 67.8%, respectively. Multivariate analysis showed that tumor residual (P=0.001) and recurrence (P<0.01) were independent prognostic factors for survival. Conclusions: The ETA is safe and feasible in selected patients with sinonasal tumor invading the anterior skull base. Tumor residual and recurrence are independent prognostic factors for survival.

Endoscopic transpterygoid transmaxillary approach to the upper parapharyngeal space / 解剖学报

Objective To present anatomical landmarks for endoscopic transpterygoid transmaxillary approach to the upper parapharyngeal space. Methods Anatomy of the upper parapharyngeal space using endoscopic endonasal transpterygoid transmaxillary approach was performed in cadaveric head. The distances between medial pterygoid plate, lateral pterygoid plate and styloid process were measured, respectively. The distances between lateral pterygoid plate, sphenoid spine and the entrance of carotid canal were also investigated. Results The dissection was performed in 10 fresh cadaver heads (20 sides). The distance between medial pterygoid plate, lateral pterygoid plate and styloid process were (28.1±3.3)mm and (18.9±4.9)mm respectively. The distances between lateral pterygoid plate, sphenoid spine and the entrance of carotid canal were (14.1±3.7) mm and (6.7±1.5) mm respectively. Pharyngobasilar fascia, medial pterygoid muscle and tensor veli palatini muscle were key landmarks of the upper parapharyngeal space. Conclusion The bone landmarks of lateral pterygoid plate and sphenoid spine are effective in identification of the entrance of carotid canal, which is helpful to locate the parapharyngeal segment of internal carotid artery.

Ototoxicity of kanamycin sulfate in adult rats and its underlying mechanisms / 生理学报

The aim of the present study was to assess the ototoxicity of kanamycin sulfate (KM) in adult rats and its underlying mechanism. Forty male Sprague-Dawley rats (6-7 weeks old) were randomly divided into the experimental group and the control group. The animals in the experimental group were injected subcutaneously with KM (500 mg/kg per day) for two weeks, and the control group received equal volume of normal saline. To assess the ototoxicity of KM, the auditory brainstem response (ABR) was recorded to monitor the changes in hearing thresholds, and the density of spiral ganglion cells (SGCs) and morphology of cochlea were observed using surface preparations and frozen sections of cochlea. The results showed that the hearing threshold of rats in the experimental group was elevated by more than 60 dB across all the frequencies two weeks after the first administration of KM. And in the experimental group, the density of SGCs became lower, and organ of Corti suffered loss of hair cells. The loss of outer hair cells (OHCs) was more severe than that of inner hair cells (IHCs), correlated with the density decrease of SGCs. We conclude that the ototoxicity of KM in the adult rats was apparent and the underlying mechanism is associated with the loss of SGCs and hair cells.

Olfactory ensheathing cells promote the survival of newborn rat spiral ganglion cells in vitro / 生理学报

The objective of this study is to explore whether olfactory ensheathing cells (OECs) can promote the survival of newborn rat spiral ganglion cells (SGCs) and the underlying possible mechanisms. Co-culture of OECs from adult rats with SGCs from newborn rat cochlea was established and single culture of SGCs acted as control. OECs were obtained and purified based on their special rate of attachment which was different from the other harvested cell types during culture. OECs and SGCs were immunocytochemically characterized and confirmed by expression of low-affinity nerve growth factor receptor p75 or positive label of neuron-specific betaIII-tubulin. To investigate the mechanisms of the role of OECs in survival of SGCs, brain derived neurotrophic factor (BDNF) and anti-BDNF antibody (IgY) were added into the media of the co-cultures respectively, and the surviving SGCs were examined after treatment. Single layer of OECs (92% pure) was seen seven days after plating. Surviving SGCs, which extended their primary neurites, were found on the surface of the layer in the co-cultures. When OECs and SGCs were co-cultured, the number of surviving SGCs was significantly greater than that in the single culture (P<0.01). Nine days after culture, there was even no change in the number of surviving SGCs in the co-culture while the number reduced to almost zero in the single culture. In comparison with co-culture without treatment, addition of BDNF (500 pg/mL) into the media had no obvious promoting effect on the survival of SGCs. The number of surviving SGCs reduced significantly when anti-BDNF antibody was applied into the media of co-cultures (P<0.01). These results suggest that OECs can promote the survival of SGCs when they are co-cultured in vitro. BDNF released from OECs, as one of the survival factors, plays an important role in the survival of SGCs.