Transoral Robotic Surgery in the Management of a Tongue Base Schwannoma

The Role of TORS in the Management of Benign Pathology of the Base of Tongue: A Systematic Review

OBJECTIVE

Transoral robotic surgery (TORS) is becoming increasingly popular in head and neck surgery. Its applications have expanded beyond oncologic indications to obstructive sleep apnea syndrome (OSAS) and, more recently, to benign pathologies.

DATA SOURCES

A systematic search for articles published in the PubMed and Google Scholar databases between January 2003 and December 2023 was performed using the following combined search query (robot OR sleep OR apnea OR syndrome) AND (robot OR tongue OR base).

REVIEW METHODS

Given the limited literature, we conducted a systematic review focusing on the outcomes of TORS for benign pathologies of the base of the tongue. Our search methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

We found 16 articles that met our inclusion criteria. These were mainly case reports and a few case series.

CONCLUSIONS

Compared to other transoral techniques, TORS offers better exposure, visualization, and access to the oropharynx, especially the base of the tongue, even in benign pathology. TORS should be considered a feasible, safe, and effective technique. Several more studies are needed to effectively evaluate the role of TORS in benign pathology that does not correlate with OSAS.

Transoral diode laser-assisted resection of a tongue base schwannoma

Schwannomas are benign peripheral nerve sheath tumours with a low risk of malignant transformation. About 25%-40% are in the head and neck region with the posterior third of the tongue being a rather rare site of its growth, and a lesion at this site is understandably difficult to approach and treat. Being benign and encapsulated, surgical excision is in the mainstay of treatment. Symptoms can range from a globus pharyngeus and dysphagia to airway compromise depending on the size and site. Traditionally, a paramedian lip split approach with paramedian mandibulotomy and mandible swing may be used. However, some recent reports of the use of carbon dioxide laser and robotic surgery for tongue base lesions are seen in the literature. Our case report is a unique addition to the management strategies for such tongue base lesions as we employed diode 980 nm laser using a minimally invasive transoral approach with a successful outcome.

Mesenchymal neoplasms of the tongue: A clinicopathologic study of 93 cases

Neoplasms of the tongue are relatively common, and the vast majority are epithelial in phenotype. Although uncommon, a diverse and distinctive array of mesenchymal neoplasms arises in this anatomic site. To increase our understanding of these lesions, we reviewed our experience of MNs of the tongue and described their clinicopathologic features. The pathology archives from 2005 to 2021 and the consultation files of one of the authors were queried for all MNs of the tongue. We reviewed the histologic slides and ancillary studies and obtained clinical data from the available medical records. Ninety-three cases were identified, and they form the study cohort - to our knowledge, this is the largest series of mesenchymal neoplasms of the tongue. Forty-eight patients were female, and forty-five were male, with a mean age of 51 years (range: 1-94 years). The tumors included 43 (46.2%) hemangiomas, 14 (15%) granular cell tumors, 8 (9%) lipomas, 4 (4.3%) schwannomas, 4 (4.3%) solitary fibrous tumors - all with low risk of progression based on risk stratification criteria, 2 (2.2%) lymphangiomas, 3 (3.2%) Kaposi sarcomas, 2 (2.2%) chondromas, 2 (2.2%) myofibromas, 1 (1.1%) solitary circumscribed neuroma, 1 (1.1%) perineurioma, 1 (1.1%) neurofibroma, 1 (1.1%) ectomesenchymal chondromyxoid tumor, 1 (1.1%) atypical glomus tumor with a NOTCH2 rearrangement and TLL2 mutation, 1 (1.1%) spindle cell rhabdomyosarcoma, 1 (1.1%) pleomorphic fibroblastic sarcoma, 1 (1.1%) malignant rhabdoid tumor, 1 (1.1%) leiomyosarcoma, 1 (1.1%) angiosarcoma, and 1 (1.1%) alveolar soft part sarcoma. Most of the patients underwent surgical excision, and 1 patient (with hemangioma) underwent embolization. On follow-up, the patient with spindle cell rhabdomyosarcoma developed postoperative numbness at the surgical site and was disease-free through 17 months of follow-up. The patient with leiomyosarcoma declined adjuvant radiation and developed metastasis to the lung at 22 months. The patient with alveolar soft part sarcoma had metastases to the lung at the time of diagnosis and received adjuvant chemotherapy. The remaining patients had no local or distant recurrence. MNs of the tongue are usually benign and characterized by either endothelial, adipocytic, or schwannian differentiation. The mainstay of treatment is surgical excision with the extent of excision determined by tumor type. Adjuvant therapy is reserved for high-grade sarcomas.

Preoperative predictors of difficult oropharyngeal exposure for transoral robotic surgery: The Pharyngoscore

BACKGROUND

Insufficient exposure may require termination of procedure in transoral robotic surgery (TORS). The aim of study was to develop a "Pharyngoscore" to quantify the risk of difficult oropharyngeal exposure (DOE) before TORS.

METHODS

Three-hundred six patients undergoing any surgical procedure at one Academic Hospital were prospectively enrolled. Oropharynx was exposed with Feyh-Kastenbauer retractor. Exposure was evaluated by direct and endoscopic visualization of the four oropharyngeal subsites. Preoperative clinical/anthropometric parameters were studied in good oropharyngeal exposure and DOE groups. Logistic regression was performed to explore association between clinical/anthropometric parameters and DOE. Statistically significant parameters at multivariate analysis were incorporated into a nomogram.

RESULTS

Sixty-five (21.2%) subjects were characterized by DOE. Variables associated with DOE at univariate analysis were male (p = 0.031), modified Mallampati Class (MMC) ≥ III (p < 0.001), smaller interincisor gap (p < 0.001), and larger neck circumference (p = 0.006). MMC, interincisor gap, and neck circumference were significant at multivariate analysis and were presented with a nomogram for creating the Pharyngoscore.

CONCLUSIONS

The Pharyngoscore is a promising tool for calculating DOE probability before TORS.