Extended endonasal approach versus maxillary swing approach to the parapharyngeal space

Surgery of major salivary gland cancers: REFCOR recommendations by the formal consensus method

OBJECTIVE

To determine the role of surgery of the primary tumor site in the management of primary major salivary gland cancer.

MATERIAL AND METHODS

The French Network of Rare Head and Neck Tumors (REFCOR) formed a steering group, which drafted a non-systematic narrative review of the literature published on Medline, and proposed recommendations. The level of adherence to the recommendations was then assessed by a rating group, according to the formal consensus method.

RESULTS

Treatment of salivary gland tumor is mainly surgical. The gold standard for parotid cancer is a total parotidectomy, to obtain clear margins and remove all intraparotid lymph nodes. For low-grade tumors, partial parotidectomy with wide excision of the tumor is acceptable in the case of postoperative diagnosis on definitive histology. In the event of positive margins on definitive analysis, revision surgery should be assessed for feasibility, and performed if possible.

CONCLUSION

Treatment of primary major salivary gland cancer is based on surgery with clear resection margins, as far away as possible from the tumor. The type of surgery depends on tumor location, pathologic type and extension.

Endoscopic endonasal combined transoral medial approach to the nasopharynx, parapharyngeal space, and jugular foramen

OBJECTIVE

This study aimed to validate the feasibility of an endoscopic endonasal combined transoral medial approach for treating lesions in the nasopharynx, parapharyngeal space (PPS), and jugular foramen.

METHODS

Anatomical and imaging information of six patients who underwent surgery via this approach were reviewed and analyzed.

RESULTS

The feasibility and advantages of the endoscopic endonasal combined transoral medial approach, which uses an inside-to-outside medial surgical corridor, were identified. Total resection was achieved in 3 cases with benign tumors. Safe resection margins were obtained in 2 cases with recurrent nasopharyngeal carcinoma (NPC). Pathological biopsy of NPC lesion between the Eustachian tube and arterial sheath was achieved. The internal carotid artery (ICA) was accurately located and protected in all cases and no complications occurred.

CONCLUSION

Lesions in the nasopharynx, PPS, and jugular foramen can be directly assessed via this approach. The ICA can be well identified during the surgery.

Anatomical Variations of the Ascending Pharyngeal Artery: Implications for Endoscopic Surgery in the Parapharyngeal Space

Objectives: The ascending pharyngeal artery (APA) travels with the parapharyngeal internal carotid artery (pICA) in the parapharyngeal space (PPS). This study aimed to investigate the anatomical variations of the APA, and to explore their implications for endoscopic surgery in the PPS. Methods: Dissection of the APA in the PPS was performed on 10 cadaveric specimens (20 sides). The relationship between APA and PPS tumors was retrospectively reviewed in 20 patients, attempting to ascertain the APA during the resection of 10 pre-styloid and 10 retro-styloid PPS tumors. Results: During the cadaveric dissections, the APA was identified at the medial, posteromedial, or bilateral aspects of the pICA in 12 (60%) and 4 (20%) sides, respectively. In the remaining 4 sides (20%), the APA branched into several subcategory arteries lying at the medial and lateral aspects of the pICA. Branches of the APA were observed in 13/20 sides (65%). Two branches were found in 9/13 sides and 3 branches in 4/13, respectively. The APA was only identifiable in 1/10 (10%) of pre-styloid tumors, a patient with basal cell adenoma. In contrast, the APA was encountered surrounding the pICA in 8/10 (80%) of patients with retro-styloid tumors, all of which were schwannomas. No inadvertent injury of the APA or the pICA occurred in this cohort. Conclusions: With identification of the ascending pharyngeal artery on preoperative magnetic resonance imaging, it may serve as an additional landmark during the endoscopic extirpation of tumors arising in the PPS.

Schwannoma Arising in Nasopharynx: A Case Report and Literature Review

Schwannoma in paranasal sinus has been known as a rare tumor in this origin. This study reports on primary schwannoma arising in the nasopharynx, which is an uncommon location. A 36-year-old female presented with nasal obstruction for one month. Physical examination revealed a nasopharyngeal mass totally occluding bilateral posterior choanae and extended downward to the oropharynx. Magnetic resonance image showed heterogeneous enhancing mass at the nasopharynx extending inferiorly to the oropharynx. The tumor was excised via endoscopic combined trans-nasal/trans-oral approach under general anesthesia. The pathologic diagnosis was consistent with schwannoma. The tumor was successfully excised with en-block resection and the patient was discharged the next day after the operation, without any postoperative complications. There was no tumor recurrence at 12-months follow-up. Schwannoma primarily arising in the nasopharynx is uncommon. Minimally-invasive surgery via the endoscopic approach can be applied for tumor removal with fewer complications and reduced risk of morbidity.

Maxillary Swing Approach for Central Skull Base Lesions in Extreme Situations: A Single-Institutional Case Series

OBJECTIVE

Radical resection of complex lesions occupying multiple compartments at the central skull base remains a significant challenge, since surgical outcomes may be compromised by insufficient exposure and inappropriate techniques. However, the efficiency of the maxillary swing approach for these lesions has not been sufficiently evaluated. Careful assessment of lesion characteristics must be performed when selecting the appropriate procedure.

METHODS

Between May 2006 and February 2017, 17 patients underwent resection of extensive lesions in the central skull base using the maxillary swing approach. As shown in the representative cases, data regarding clinical findings and technical considerations were reviewed.

RESULTS

Complete resection was achieved in all patients. The pathological findings were diverse, and the majority were schwannomas (9 cases, 52.94%), followed by meningiomas (World Health Organization II) (3 cases, 17.65%). Complications were managed as described in the case illustrations, and symptoms improved with time. The follow-up duration ranged from 62 to 192 months (median, 114 months), while 2 patients were lost to the follow-up. No mortality was observed. Two patients who experienced malignancy relapse were still under observation due to their asymptomatic status.

CONCLUSIONS

Our preliminary results suggest that the maxillary swing approach can be an alternative option for managing extreme cases, such as large, extensive, hypervascularized masses with fibrous or calcified consistency, or for recurrent lesions in the central skull base. En bloc resection can be successfully obtained, resulting in long-term local control.

Exploration of anatomical landmarks for performing an endoscopic transoral nasopharyngectomy

BACKGROUND

Performing a nasopharyngectomy via a transoral approach has been reported; however, defining landmarks to facilitate this approach has not been addressed. This study aims to explore anatomical landmarks to aid in performing a nasopharyngectomy via the transoral corridor.

METHODS

An endoscopic transoral nasopharyngectomy was performed on six cadaveric specimens (12 sides). Related anatomical landmarks were defined, and the strategy to preserve the parapharyngeal internal carotid artery (pICA) was explored.

RESULTS

An endoscopic transoral nasopharyngectomy was successfully achieved in all 12 sides. Utilizing the pterygoid hamulus as a landmark, the cartilaginous ET and attachments could be adequately exposed. Identification of the pICA is a prerequisite prior to Eustachian tube (ET) transection. The sphenoidal spine and the petrotympanic fissure could be sufficiently revealed in all 12 sides, which aided in transection of the cartilaginous ET without pICA injury. The ET and the prevertebral contents could be adequately removed via the transoral corridor.

CONCLUSION

The pterygoid hamulus, sphenoidal spine and petrotympanic fissure serve as reliable landmarks for performing a transoral nasopharyngectomy. Identification of the pICA is a prerequisite prior to transection of the ET to avoid pICA injury.

An Endoscopic Endonasal Nasopharyngectomy with Posterolateral Extension

Background Invasion depth influences the choice for extirpation of nasopharyngeal malignancies. This study aims to validate the feasibility of endoscopic endonasal resection of lesions with a posterolateral invasion. As a secondary goal, the study intends to propose a classification system of endoscopic endonasal nasopharyngectomy determined by the depth of posterolateral invasion.

Methods Eight cadaveric specimens (16 sides) underwent progressive nasopharyngectomy using an endoscopic endonasal approach. Resection of the torus tubarius, Eustachian tube (ET), medial pterygoid plate and muscle, lateral nasal wall, and lateral pterygoid plate and muscle were sequentially performed to expose the fossa of Rosenmüller, petroclival region, parapharyngeal space (PPS), and jugular foramen, respectively.

Results Technical feasibility of endonasal nasopharyngectomy toward a posterolateral direction was validated in all 16 sides. Nasopharyngectomy was classified into four types as follows: (1) type 1: resection restricted to the posterior or superior nasopharynx; (2) type 2: resection includes the torus tubarius which is suitable for lesions extended into the petroclival region; (3) type 3: resection includes the distal cartilaginous ET, medial pterygoid plate, and muscle, often required for lesions extending laterally into the PPS; And (4) type 4: resection includes the lateral nasal wall, pterygoid plates and muscles, and all the cartilaginous ET. This extensive resection is required for lesions involving the carotid artery or extending to the jugular foramen region.

Conclusion Selected lesions with posterolateral invasion into the PPS or jugular foramen is amenable to a resection via expanded endonasal approach. Classification of nasopharyngectomy based on tumor depth of posterolateral invasion helps to plan a surgical approach.

Modified Maxillary-Swing Approach for Resection of Primary Malignancies in the Pterygopalatine Fossa

Background

En bloc resection of malignancies in the pterygopalatine fossa (PPF) poses critical challenges. Using the modified maxillary-swing (MMS) approach, we achieved monobloc removal of primary malignancies in this region. This study provides a detailed account of the surgical techniques and indications used.

Methods

We enrolled seven patients with primary malignancies in the PPF during a period from January 2012 to January 2019 in this retrospective study. After malignancies were confirmed by biopsy as well as evaluation with computed tomography (CT) and magnetic resonance imaging (MRI) scans, all of the patients underwent MMS surgery under general anesthesia to extirpate these tumors. We performed regular postoperative follow-up using CT and MRI scans.

Results

En bloc resection was successfully performed in all cases. We observed negative margins in six cases and positive margins in one patient with adenoid cystic carcinoma, who received postoperative radiotherapy. The most common complication was facial numbness. During the follow-up period (range, 6-69 months), one patient suffered from recurrence, while the others did not.

Conclusion

The advantages of the MMS include a wide surgical field, full exposure, and easy manipulation. We expect this approach to become an alternative to the monobloc resection of malignancies in the PPF that involve the infratemporal fossa, maxillary sinus, nasal cavity, orbit, or oral cavity.

Endoscopic transoral nasopharyngectomy

BACKGROUND

A minimal access technique for the management of nasopharyngeal tumors extending below the palatal plane and laterally beyond the pterygoid musculature is yet to be developed. In this study we demonstrate the feasibility of endoscopic transoral nasopharyngectomy (ETON) for resection of large nasopharyngeal lesions as a natural orifice alternative to traditional approaches.

METHODS

ETON was completed in three latex-injected specimens. Surgical freedom (SF) and angles of attack (AoA) were calculated along the internal carotid artery (ICA).

RESULTS

An endoscopic transoral approach was successfully used to identify the parapharyngeal ICA and subsequently perform a complete nasopharyngeal resection. SF and AoA (sagittal) were found to be the greatest at the anterior genu of the ICA.

CONCLUSIONS

ETON is feasible. It provides wide exposure of the skull base and proximal control of the ICA. It may be indicated for the management of nasopharyngeal tumors with inferolateral extension, involving the ICA.

A Sufficient Surgical Window for Deep-Seated Extracranial Schwannomas in the Craniocervical Junction by the Anterolateral Approach

Care should be taken regarding surrounding anatomic structures during access to deep-seated extracranial schwannomas in the craniocervical junction (CCJ). Herein, we present surgical tips for extracranial schwannomas in the CCJ using the anterolateral approach. A retrospective review was performed of 3 cases of surgical treatment of extracranial schwannomas in the CCJ by the anterolateral approach, which is a presternomastoid retrojugular route to the CCJ. The combination of neck rotation and reflection of the sternocleidomastoid muscle presented a sufficient, shallow surgical field for the CCJ. We could identify tumors along the accessory nerves and internal jugular veins, and had sufficient rostrocaudal working space to resect the tumors. Two cases were enucleated total resection and 1 was subtotal resection. Two patients experienced transient postoperative vocal cord partial paralysis and 1 had transient dysphagia. These neurological complications improved within 1 month. The anterolateral approach can provide a shallow and sufficient rostral and caudal surgical window.

Transpalatal Approaches to the Skull Base and Reconstruction: Indications, Technique, and Associated Morbidity

Multiple anterior surgical approaches are available to obtain access to the nasopharynx, clivus, and craniocervical junction. These include the direct and transoral robotic surgery transpalatal, maxillary swing, and endoscopic endonasal approaches. In this article, we describe the indications for these techniques, surgical steps, and associated morbidities. This article is a PubMed literature review. A review of the literature was conducted to assess the techniques, surgical steps, and associated morbidities with transpalatal approaches to the skull base and nasopharynx. The transpalatal approach has been traditionally utilized to obtain surgical access to the nasopharynx, clivus, and craniocervical junction. Morbidity includes velopalatine insufficiency due to shortening of the soft palate from scar contraction or neuromuscular damage, thus leading to hypernasal speech and dysphagia. Middle ear effusion and oronasal or oronasopharyngeal palatal fistula are additional potential morbidities. The choice of surgical approach depends on a variety of factors including the disease location and extent, surgeon experience, and available resources.