Endoscopy-assisted transoral resection of a parapharyngeal space schwannoma without mandibular dissection

The Use of Water Sac Dilation in Resecting Parapharyngeal Space Benign Tumor via Transoral Approach

OBJECTIVES

To evaluate the effectiveness of employing the water sac dilation (WSD) method during endoscopy-assisted transoral resection of parapharyngeal space benign tumor (PSBT).

METHODS

Between February 2017 and January 2022, a total of 32 patients diagnosed with PSBT were included in this prospective study and were randomly allocated into two groups: the WSD group and the control group. Tumors of the WSD group patients were all dissected using the WSD method.

RESULTS

The final numbers of studied patients in WSD group and control group were 17 and 15, respectively. The basic information was comparable between these two groups of patients. All these patients successfully underwent tumor resection via transoral approach. The operation time, intraoperative blood loss, drainage volume on the first postoperative day, drainage duration, and the total drainage volume in the WSD group patients were significantly lower than those in the control group patients (all p < 0.05). No surgical complications occurred, and no residual tumor or recurrence could be identified at 6 months after surgery in both groups of patients.

CONCLUSION

The application of the WSD method in endoscopy-assisted transoral resection of PSBT effectively attenuated intraoperative injury, improved surgical efficiency, and accelerated postoperative recovery.

LEVEL OF EVIDENCE

3 Laryngoscope, 135:665-670, 2025.

Narrow-band imaging to enhance intraneural dissection in head and neck schwannoma surgery: a quantitative evaluation

OBJECTIVE

The objective of this study was to assess the utility of narrow-band imaging (NBI) for improving intraneural dissection during gross total resection of head and neck schwannoma. Specifically, we aimed to quantitatively evaluate whether NBI can enhance the identification of pseudocapsule and true capsule within the tumor.

METHODS

Nine schwannoma surgery cases conducted between February 2018 and October 2022 were retrospectively analyzed. The surgical procedures followed established principles with a specific focus on utilizing NBI to distinguish between the pseudocapsule and true capsule. Intraneural dissection was performed by searching for a tumor surface with a fascicle-free window, followed by longitudinal incision of the pseudocapsule. NBI was used to distinguish between the pseudocapsule and true capsule. Surgical views were captured under both white light (WL) illumination and NBI for further analysis. The brightness and contrast of the pseudocapsule and true capsule were quantitatively measured using ImageJ and were compared.

RESULTS

Under NBI, the pseudocapsule consistently appeared greenish-gray, whereas the true capsule exhibited a white appearance. Quantitative analysis revealed a statistically significant difference (p < 0.0001) in brightness between the pseudocapsule (mean grayscale value 52.1, 95%CI; 46.4-75.3) and true tumor capsule (mean grayscale value 120.8, 95%CI; 155.7-109.0) under NBI. Conversely, there was no statistically significant difference in the brightness of these structures under WL (p = 0.2067). NBI also showed significantly higher contrast between the two structures than did WL (contrast 73.6, 95%CI; 53.1-89.5 vs. 30.9, 95%CI; 1.0-47.5, p = 0.0034). Further spectral analysis revealed that the most substantial difference in brightness between the pseudocapsule and the true tumor capsule was observed in the red spectrum, with a difference in brightness of -0.6 (95%CI; -16.8-14.8) under WL and 83.5 (95%CI; 50.3-100.0) under NBI (p < 0.0001).

CONCLUSION

NBI proved to be a valuable tool for enhancing the identification of pseudocapsule and true capsule during intraneural dissection in head and neck schwannoma surgery. The improved contrast and membrane visibility offered by NBI might have the potential to reduce postoperative neurological deficits and improve surgical outcomes. Further research is warranted to validate our findings and explore the broader applications of NBI in schwannoma surgery.

Extracapsular Dissection With Narrow-Band Imaging Using the Transnasal Endoscopic Tri-port Approach for Extracranial Trigeminal Schwannoma: A Case Report

The pterygopalatine fossa and infratemporal fossa are often approached through an external incision because of their deep facial location, but this can present problems such as facial scarring and deformity. In schwannoma surgery, intraneural dissection is a useful surgical technique for achieving gross total resection while preserving the capsule, including the nerves. For appropriate enucleation and preservation of the functional nerve, it is indispensable to distinguish between the pseudocapsule and the tumor capsule. This case report presents a case of endonasal surgical intervention for an extracranial trigeminal schwannoma employing the tri-port approach and narrow-band imaging.

Endoscopic transoral approach to the lateral poststyloid space

The lateral poststyloid space (LPSS) located at the posterolateral aspect of the styloid process. This study aims to explore the anatomical relationships in LPSS via a transoral corridor, providing reference for addressing lesions extending to this region. An endoscopic transoral approach for exposure of the LPSS was performed on 6 cadaveric specimens (12 sides). Related landmarks were explored, and transoral extirpation of tumors extended into LPSS was employed in 12 patients. The deep lobe of the parotid gland, extratemporal facial nerve, and the accompanying artery in the LPSS were sufficiently exposed via the transoral corridor in all 12 cadaveric sides. The transoral corridor provided adequate exposure for tumors extending to the LPSS, and en bloc resection was achieved in these 12 patients. No facial nerve or vascular injury occurred, and no recurrence observed in this cohort with an average follow-up of 26 months. An endoscopic transoral approach provides a direct access to the LPSS. Appreciation of the anatomical relationships within the LPSS is valuable for employing a transoral extirpation of tumors extending to this specific region.

A Review of Microsurgical Resection of Recurrent Laryngeal Neurilemmoma Under Nerve Monitoring

BACKGROUND

Laryngeal neurilemmoma, especially recurrent laryngeal neurilemmoma, is a rare neural sheath tumor in head and neck. The most common symptom of laryngeal neurilemmoma is hoarseness or dysphonia, followed by dysphagia, dyspnea, and foreign body sensation. At present, surgical resection is the most effective treatment for this kind of tumor, thus making how to remove it become the most concerned problem of surgeons.

CASE PRESENTATION

On February 18, 2021, a 64-year-old male presented to our clinic with recurrent sore throat and intermittent hoarseness for 3 years. The results of electronic laryngoscope and magnetic resonance imaging showed a 25×10×21 mm well-defined tumor in the left pyriform sinus without laryngeal cartilage destruction and enlarged lymph nodes. After the initial diagnosis of recurrent laryngeal neurilemmoma, to preserve the continuity of recurrent laryngeal nerve as much as possible, the authors determine to perform anatomical resection of recurrent laryngeal neurilemmoma with operating microscope under the monitoring of recurrent laryngeal nerve function. Finally, the patient recovered completely from hoarseness during postoperative follow-up.

CONCLUSION

A complete diagnosis and treatment process of recurrent laryngeal neurilemmoma was presented by the case. Particularly, it shows the application of recurrent laryngeal nerve monitoring in the operation helps to protect the continuity of the recurrent laryngeal nerve, which lays a anatomical bases for the follow-up nerve repair.

Biomechanical characterization of isolated epineurial and perineurial membranes of rabbit sciatic nerve

Design of interface devices for effective, long-term integration into neural tissue is dependent on the biomechanical properties of the nerve membranes. Within the peripheral nerve, the two relevant connective tissue layers for interfacing are the epineurium and perineurium. Previous work has reported the forces needed to penetrate the whole nerve, but the mechanical differences between epineurium and perineurium were not reported. Design of intraneural electrodes that place electrodes within the nerve requires knowledge of the mechanics of individual tissues. This study quantified the Young's moduli and ultimate strains of the perineurium and the epineurium separately. We also measured the forces necessary to penetrate each tissue in isolation. We used a custom-built microtensile testing device to measure the Young's modulus values. The measured Young's moduli of the epineurium and the perineurium was 0.4 ± 0.1 MPa and 3.0 ± 0.3 MPa, respectively. We also measured the force required for blunt and sharp stainless steel, 100 µm diameter probes to be inserted into isolated epineurial tissue and perineurial tissue at 2 mm/s. These data provide additional guidelines for selection of materials for long-term implants that best match the tissue properties. The results will guide neural interface design such that electrodes can be placed through either the epineurium alone or both the epineurium and perineurium.