A minimally invasive endoscopic transnasal retropterygoid approach to the upper parapharyngeal space: anatomic studies and surgical implications

Nasal Endoscopic Incision and Drainage Transnasal Retropterygoid Approach to Upper Parapharyngeal Abscess: A Novel Technique

Parapharyngeal infection is a well-known disease of otorhinolaryngologists. Rapid onset, short duration, severe symptoms, and manifestations such as sore throat and dysphagia are common characteristics treated primarily by surgical incision and drainage. Traditional surgical approaches encompass endoscopic transoral/nasal, transparotid, transcervical, or a combination thereof. We report a novel technique of nasal endoscopic incision and drainage transnasal retropterygoid approach to an upper parapharyngeal abscess. This report presents a case of a 14-year-old man presented with severe right neck and head pain, who was found to have an upper parapharyngeal abscess during a nasal endoscopic parapharyngeal exploration via a retropterygoid approach. The intraoperative frozen section revealed chronic mucosal inflammation and mild to moderate dysplasia of the squamous epithelium, but no carcinoma.

Relevance of the Internal Jugular Vein for Surgery in the Upper Parapharyngeal Space

Objective: Tumors arising from the upper parapharyngeal space (UPPS) may have intimate relationships with the internal carotid artery (ICA) and the internal jugular vein (IJV). The significance of the ICA in UPPS has been sufficiently articulated, whereas the relevance of the IJV has not been addressed. This study aimed to assess the anatomical variations of the IJV within the UPPS, and to explore its implications for surgical procedures. Methods: An endoscopic dissection of the IJV was performed on 10 cadaveric specimens. In addition, 30 patients who underwent transoral or transcervical resection of UPPS tumors were retrospectively reviewed to characterize the IJV and its relation to the tumor. Results: On the cadaveric specimens, the IJV was located at the posteromedial and posterolateral aspects of the styloid process in 13 (65%) and 7 (35%) sides, respectively. In our clinical series, the IJV was not encountered in 18 patients with pre-styloid tumors. In 12 patients harboring retro-styloid tumors, the IJV was partially (n = 5) or completely (n = 7) compressed and was displaced into the posterolateral aspect of the tumor. The IJV was injured intraoperatively in 1 patient, requiring an immediate conversion to an open transcervical corridor that allowed its exposure and ligation without difficulty. Conclusion: This study characterizes the IJV and its relationship with adjacent neurovascular structures in the UPPS, which may provide further safeguards during transoral and transcervical procedures in the UPPS.

Maximal exposure of the parapharyngeal internal carotid artery via transnasal and transoral corridors

BACKGROUND

The parapharyngeal internal carotid artery (pICA) could be surgically exposed through the transnasal and transoral corridors. However, their potential degree of exposure has not been established sufficiently. This study aims to elucidate the maximal exposure of the pICA via the transnasal and transoral corridors.

METHODS

An endonasal transpterygoid nasopharyngectomy for exposure of the pICA was performed on eight cadaveric specimens (16 sides), while a transoral approach for exposure of the pICA was performed on six additional specimens (12 sides). In addition, the CT angiography of 60 consecutive patients (120 sides) was analyzed to establish the potential maximal exposure of the pICA through each corridor.

RESULTS

The hard palate becomes a restricting factor for the inferior exposure of the pICA via the transnasal approach, whereas the entire pICA segment could be adequately displayed through the transoral corridor. The maximal exposed length of the pICA for a transnasal and transoral approach was 3.08 ± 0.30 cm and 6.56 ± 0.57 cm, respectively. This difference was statistically significant (p < 0.001).

CONCLUSION

An endonasal exposure of the pICA seems limited to its superior aspect, whereas the transoral corridor could provide adequate exposure of the entire length of pICA.

Endoscopic transoral approach to the parapharyngeal space: technical nuances and preliminary results

OBJECTIVE

Surgical management is the mainstay of treatment for tumours in the parapharyngeal space. This study aimed to evaluate the indications, limits and technical nuances of the endoscopic transoral approach.

METHOD

Thirteen patients with parapharyngeal space tumours that were treated between May 2017 and November 2020 were included in this retrospective study.

RESULTS

All patients underwent surgery for complete oncological resection except one patient who received treatment for diagnostic purposes. No major complications were reported, with excellent control of the vital structures of the parapharyngeal space.

CONCLUSION

The endoscopic transoral approach to the parapharyngeal space is a promising alternative approach for selected parapharyngeal space tumours with satisfactory outcomes.

[Endoscopic transoral retropharyngeal lymphadenectomy]

Objective:The aim of this study is to explore the anatomy and surgical approach of retropharyngeal lymphadenectomy via endoscopic transoral approach. Methods:The retropharyngeal spaces were studied with three fresh frozen cadaver head （6 sides） in the anatomical laboratory of Eye, Ear, Nose and Throat Hospital of Fudan University through endoscopic transoral approach. The superior pharyngeal constrictor muscle, medial pterygoid muscle, tendon of tensor veli palatini muscle, fat of prestyloid space, ascending palatine artery and its branches, styloglossus, stylopharyngeus, stylohyoideus, external carotid artery, levator veli palatini, carotid sheath, ascending pharyngeal artery and longus capitis muscle were revealed in order. The above-mentioned structures were photographed with a 0° Karl Storz nasal endoscope and adjacent relationships were recorded. A case of metastatic retropharyngeal lymphadenopathy was reviewed and the surgical methods and techniques of retropharyngeal lymphadenectomy via endoscopic transoral approach were introduced in detail. Results:The retropharyngeal space and related anatomical structures were exposed through endoscopic transoral approach in all specimens. The styloglossus, stylopharyngius and levator veli palatini are the markers of locating the internal carotid artery. The superior pharyngeal constrictor muscle, medial pterygoid muscle, styloid muscle group, longus capitis muscle and carotid sheath are the markers that can be used to locate the retropharyngeal lymph nodes. Ascending palatine artery, ascending pharyngeal artery and internal carotid artery are the main arteries involved in retropharyngeal lymphadenectomy via endoscopic transoral approach. Conclusion:Endoscopic transoral approach is a new surgical technique to perform retropharyngeal lymphadenectomy safely and completely.

Endoscopy-Assisted Transoral Approach to Resect Parapharyngeal Space Tumors: A Systematic Review and Meta-Analysis

OBJECTIVES

By comparing the endoscopy-assisted transoral approach (EATA) with external approaches (EAs) for the resection of parapharyngeal space tumors (PPSTs), we determined whether the EATA has advantages in terms of operation time, intraoperative bleeding volume, postoperative hospitalization, drainage volume, and complications. At the same time, we summarized the surgical indications for the EATA.

METHODS

Systematic literature retrieval was performed in the PubMed, Web of Science, Embase, CNKI, Wanfang, and CQVIP databases up to February 2020. We calculated the mean difference (MD) with a 95% confidence interval (CI) for continuous outcomes and pooled odds ratio (OR) with 95% CI for dichotomous outcomes. The measured outcomes were operative time, bleeding volume, postoperative hospitalization, drainage volume, and complications.

RESULTS

Seven studies involving 318 patients were eligible. Of these patients, 145 patients underwent EATA and 173 patients underwent EA surgery. All the former tumors were benign and located medial or anteromedial to the carotid sheath except for the unrecorded tumors. Compared with EAs, the EATA significantly shortened the operation time (MD = -5.56 min, 95% CI: -9.58 to -1.55), shrank the bleeding volume (MD = -89.02 ml, 95% CI: -126.16 to -51.88), shortened the postoperative hospitalization (MD = -2.44 days, 95% CI: -3.37 to -1.51), reduced the drainage volume (MD = -32.97 ml, 95% CI: -36.24 to -29.70), and lowered the incidence of complications (OR = 0.30, 95% CI: 0.16 to 0.59).

CONCLUSION

As for PPSTs, with an appropriate and precise patient selection, the EATA is a safe, effective, minimally invasive, and aesthetic surgical modality. Laryngoscope, 2021.