The transcervical-transparotid corridor for management of parapharyngeal space neoplasms: strengths and limits in a bi-institutional retrospective series.

BACKGROUND AND PURPOSE: Parapharyngeal space (PPS) neoplasms represent 1% of all head and neck tumors and are mostly benign. Surgery is the mainstay of treatment and the transcervical-transparotid (TC-TP) corridor still represents the workhorse for adequate PPS exposure. Our series investigates strengths and limits of this approach on a multi-institutional basis. METHODS: We reviewed consecutive patients submitted to PPS surgery via TC-TP route between 2010 and 2020. Hospital stay, early and long-term complications, and disease status were assessed. RESULTS: One hundred and twenty nine patients were enrolled. Most tumors were benign (79.8%) and involved the prestyloid space (83.7%); the median largest diameter was 4.0 cm. The TC-TP corridor was used in 70.5% of patients, while a pure TC route in about a quarter of cases. Early postoperative VII CN palsy was evident in 32.3% of patients, while X CN deficit in 9.4%. The long-term morbidity rate was 34.1%, with persistent CN impairment detectable in 26.4% of patients: carotid space location, lesion diameter and malignant histology were the main independent predictors of morbidity. A recurrence occurred in 12 patients (9.4%). CONCLUSIONS: The TC-TP corridor represents the benchmark for surgical management of most of PPS neoplasms, though substantial morbidity can still be expected.

Parapharyngeal space tumors: a twenty-year single-center retrospective analysis on the effectiveness of transcervical and transoral approaches on local control and disease-specific survival.

INTRODUCTION: To retrospectively analyzed our twenty-years single-center experience in the treatment of PPS tumors, focusing on the selection of surgical approach and the survival outcome. METHODS: Tumors involving the PPS between January 2000 and February 2022 were retrospectively included. The surgical approach was dictated by the localization of the tumor, its dimensions, the relation to anatomic structures and its etiology. RESULTS: 34 patients were included in the study. The median age was 50.5 yr, with a gender female prevalence. Most tumors were benign and non recurrent. 20 tumors were treated through lateral approach (transcervical or transcervical-transparotid), 11 through medial approach (transoral), and only 3 tumors were approached by multiple corridors. The 5 years disease free survival (DFS) was 78.8 % (CI 78-79.3 %). CONCLUSIONS: In our experience, the transcervical and transoral approaches can be considered the ideal surgical approach to manage tumors of PPS, especially in cases of benign neoplasms.

Perioperative stroke in parapharyngeal space schwannoma: an unusual, dreaded complication.

BACKGROUND: Post-styloid parapharyngeal space tumours (PPS) have a notorious course owing to their anatomy and proximity to neurovascular bundles. Nerve injuries are usual outcomes in schwannomas. Our case is the first documented complication of contralateral hemiplegia occurring in the postoperative period in a benign PPS tumour. CASE REPORT: A 24-year-old presented with a swelling on the left lateral aspect of the neck, diagnosed as a PPS schwannoma. He underwent transcervical excision with mandibulotomy with extracapsular dissection of the tumour. Contralateral hemiplegia, as a dreaded complication, was encountered. He was managed conservatively according to ASPECTS stroke guidelines by the critical care team. On a regular follow-up, he noticed an improvement in the lower limb with subsequent upper limb power. CONCLUSION: Perioperative stroke is a dreaded complication involving PPS in large benign tumours. To prevent unforeseen circumstances, necessary preoperative patient counselling and immense intraoperative care should be taken while dissecting the major vessels.

Differentiation of neurogenic tumours and pleomorphic adenomas in the parapharyngeal space based on texture analysis of T2WI.

BACKGROUND: The purpose of this study was to identify neurogenic tumours and pleomorphic adenomas of the parapharyngeal space based on the texture characteristics of MRI-T2WI. METHODS: MR findings and pathological reports of 25 patients with benign tumours in the parapharyngeal space were reviewed retrospectively (13 cases with pleomorphic adenomas and 12 cases with neurogenic tumours). Using PyRadiomics, the texture of the region of interest in T2WI sketched by radiologists was analysed. By using independent sample t-tests and Mann‒Whitney U tests, the selected texture features of 36 Gray Level Co-Occurrence Matrix (GLCM) and Gray Level Dependence Matrix (GLDM) were tested. A set of parameters of texture features showed statistically significant differences between the two groups, which were selected, and the diagnostic efficiency was evaluated via the operating characteristic curve of the subjects. RESULTS: The differences in the three parameters - small dependence low level emphasis (SDLGLE), low level emphasis (LGLE) and difference variance (DV) of characteristics - between the two groups were statistically significant (P < 0.05). No significant difference was found in the other indices. ROC curves were drawn for the three parameters, with AUCs of 0.833, 0.795, and 0.744, respectively. CONCLUSIONS: There is a difference in the texture characteristic parameters based on magnetic resonance T2WI images between neurogenic tumours and pleomorphic adenomas in the parapharyngeal space. For the differential diagnosis of these two kinds of tumours, texture analysis of significant importance is an objective and quantitative analytical tool.

[Internal carotid artery pseudoaneurysm caused by parapharyngeal abscess: A case report].

Pseudoaneurysms of the neck are seldom, and those caused by neck infections especially parapharyngeal abscess are even rarer. However, it is life-threatening and may bring sudden death due to the obstruction of airway and the pseudoaneurysms rupture. We analyzed the clinical features, diagnosis and treatment of the disease through a case summary and literature review in order to guide clinical diagnosis and treatment of pseudoaneurysms. The patient, whom we presented was an 87-year-old male and admitted in emergency of our hospital with the chief complaint of neck swelling for 7 days and shortness of breath for 2 days. Cervical ultrasound examination showed that there was an liquid dark area next to the left common carotid artery which was approximately 8.0 cm × 5.0 cm, consideration of formation of left carotid artery pseudoaneurysm, and the liquid dark area which was visible on the right considered of pseudoaneurysm or infection. Angiography of neck showed a clustered high-density shadow around the bifurcation of the left carotid artery, with an overall range of approximately 65 mm × 52 mm × 72 mm, the pseudoaneurysms for sure, while on the right side of the lesion, mixed low density shadows with air could be seen, the parapharyngeal abscess for sure.Then he was diagnosed as the pseudoaneurysm of left internal carotid artery which was caused by parapharyngeal abscess. After tracheal intubation and anti-infection treatment, the patient died due to hemorrhagic shock of the ruptured of the pseudoaneurysm. Morever we performed literature search on PubMed, Wanfang database and CNKI with keywords of "neck pseudoaneurysm, neck infection, parapharyngeal abscess" and enrolled 10 cases. Then we summarized the clinical characteristics and treatment. We analyzed and summarized the 10 case reports, in which the number of male was 7. Among them, there were 4 pediatric, and 6 adults were enrolled overall. Most of the symptoms were neck swelling, and the diseased blood vessel was mainly the right internal carotid artery which accounted for half overall. All the patients underwent surgical intervention, and recovered well. So we draw the conclusion that the clinical incidence of cervical pseudoaneurysms is low and can be caused by a variety of factors, especially caused by infectious factors. When a patient has a progressive pulsating mass in the neck, the preliminary diagnosis should be made by ultrasound as soon as possible, and the aortic enhancement CT should be used to further confirm.For a patient with cervical pseudo-aneurysms caused by parapharyngeal infections, he should take operation timely combined with antibiotic treatment in time.

Synchronous pleomorphic adenoma in parotid gland and parapharyngeal space: a case report and literature review.

Synchronous pleomorphic adenoma in the parotid gland and parapharyngeal space are rare. We report a case of simultaneous pleomorphic adenoma in parotid gland and parapharyngeal space in a 65-year-old male presenting to the ENT outpatient department at Northwest General Hospital, Peshawar. The patient presented with a left parotid lump, intra oral examination of which revealed the left palatine tonsil to have been pushed medially. CT of the neck showed a completely separate lump in the left parapharyngeal space, and FNAC of the parotid lump was suggestive of mucoepidermoid carcinoma. The superficial parotid lump was excised first, and the parapharyngeal growth was accessed intraorally and excised. Histopathology revealed both the growths to be pleomorphic adenomas. It is important to raise awareness of synchronous salivary gland tumours, which are a rare occurrence, to highlight its optimal investigation to ensure complete surgical excision, and appropriate management.

[Schwannoma of the parapharyngeal space]. / Shvannoma parafaringeal'nogo prostranstva.

Schwannoma is a benign neoplasm that develops from the Schwann cells of the nerve sheath. The share of neurogenic tumors of the parapharyngeal space accounts for 0.5% of all neoplasms of this localization. The article demonstrates a case from practice, presents the clinical features, diagnostics and methods of treatment for patients with pharyngeal neuromas. The peculiarity of the presented clinical observation is due to the rare occurrence of this pathology and the large size of the schwannoma in the long-term asymptomatic course of the disease.

Evaluation of Carotid Space Schwannoma Using Ultrasonography: Characteristics and Role in Defining the Nerve of Origin.

OBJECTIVES: We aimed to evaluate the ultrasonography (US) characteristics of carotid space schwannoma and their role in identifying the nerve of origin. METHODS: This prospective study enrolled patients with cervical carotid space schwannoma accessible by US. The US characteristics of vagus nerve schwannomas (VNSs) and sympathetic nerve schwannomas (SNSs) were assessed; a carotid space schwannoma was defined as a VNS if the tumor originated in the mid-vagal region and an SNS if it arose posterior to the intact vagus nerve, displacing the vagus nerve anteriorly. RESULTS: Twenty patients with carotid space schwannoma were enrolled. The vagus and sympathetic nerves were identified as the nerve of origin in 12 and 8 patients, respectively. VNSs were centered at levels II, III, and IV in 5, 3, and 4 patients, respectively, while SNSs were centered at levels II (7 patients) and IV (1 patient) (P = .105). The maximal diameters were 3.2 and 4.8 cm for VNSs and SNSs, respectively (P = .011). Internal vascularity was absent and low in 9 and 3 VNSs, respectively, and low and intermediate in 4 SNSs each (P = .002). Twelve patients with VNSs underwent active surveillance without immediate surgery; no adverse events occurred during the 55.2-month follow-up period. Eight patients with potential SNSs underwent surgery, confirming the sympathetic nerve as the nerve of origin. CONCLUSIONS: US facilitates identification of the nerve of origin in cervical carotid space schwannoma. VNSs are more frequent in infrahyoid locations and tend to be smaller in size with lower vascularity compared with SNSs on US.

Hydatid Cyst of the Oromaxillofacial Region - A Rare Location: A Case Report and Review of the Literature.

Oromaxillofacial hydatid cysts are rare, even in countries where echinococcosis is endemic. This study aimed to describe an isolated oromaxillofacial hydatid cyst and to discuss the epidemiology, clinical features, and treatment thereof. The authors report the case of a 12 year-old boy who presented with a 2-week history of an enlarging hydatid cyst in the parapharyngeal space extending to the neck, with no pulmonary or hepatic involvement. We present our clinical findings, diagnostic techniques, and treatment and review the relevant literature. Forty-one cases, with a male:female ratio of 1.21:1, have been reported, mostly in patients aged 20 to 40 years (both sexes). Oromaxillofacial hydatid cysts are most commonly located in the parotid gland (19.51%, n = 8), submandibular region including the submandibular gland (17.07%, n = 7), and infratemporal fossa (14.63%, n = 6). Only 2 (4.88%) cases of hydatid cysts in the parapharyngeal space have been reported before. Although isolated parapharyngeal space hydatid cysts are rare, oromaxillofacial surgeons should consider relevant diagnostic and therapeutic procedures to ensure complete resection.

Management of parapharyngeal space tumors with transparotid-transcervical approach: analysis of prognostic factors related with disease-control and functional outcomes.

PURPOSE: Different therapeutic strategies have been developed to improve surgical and functional outcome of parapharyngeal space (PPS) neoplasms. The transparotid-transcervical approach (TTa) is a valid surgical option to manage most PPS tumors. Its short- and long-term disease control and cranial nerve (c.n.) function outcomes have not been discussed extensively. METHODS: All patients who underwent TTa over a 10-year period at a tertiary academic center were retrospectively reviewed. Data about preoperative imaging, clinical presentation, tumor's size, location and histology, and postoperative oncological and functional results were registered and analyzed. RESULTS: Sixty patients matched the inclusion criteria. Most of the lesions were benign (71.7%), involved the prestyloid PPS (63.3%) and measured more than 30 mm (75%). Fifty-two (86.7%) lesions were resected en-bloc. Clear margins were achieved in 91.7% of the cases, with positive margins solely associated with malignancy (p = 0.008). Post-operative c.n. function was satisfactory, with X c.n. function significantly associated with the retrostyloid location (p = .00) and neurogenic tumors (p = 0.02). Local disease-control was achieved in 96% of the cases after a median follow-up of 46 (± 19.7-82.0 IQR) months. CONCLUSIONS: The TTa was safe and effective, achieving a satisfactory local control rate. Nevertheless, malignancies maintain a higher rate of positive margin due to their infiltrative nature and the complex anatomy of the PPS. In such cases, multiportal approaches might be more effective. However, post-operative c.n. function remained satisfactory, irrespective of lesions' size and histopathologic behavior. A higher X c.n. deficit rate was observed in retrostyloid and neurogenic lesions.

Trans-Oral Robotic Surgery: 14 Cases of Pleomorphic Adenoma of the Parapharyngeal Space.

PURPOSE: The aim of this study has been to describe our experience with pleomorphic adenomas of the parapharyngeal space (PPS) treated with trans-oral robotic surgery (TORS). Tumors arising from the PPS comprise less than 0.5% of all head and neck tumors. Salivary gland tumors account for 40% to 50% of PPS lesions with pleomorphic adenomas representing the most common salivary tumors (80%-90%). Parapharyngeal space tumors cause nonspecific symptoms and may be difficult to diagnose. METHODS: In our study a preoperative diagnosis was conducted by fine needle aspiration biopsy and magnetic resonance imaging and the results were used to plan the correct surgical approach. RESULTS: In all cases we were able to employ TORS, a minimally invasive procedure that allows us to operate in narrow and anatomically complex spaces that we can only reach thanks to the use of well-articulated hand pieces. CONCLUSIONS: This report indicates that TORS is a safe surgical procedure for the excision of benign tumors of the PPS in selected cases.

Surgical Treatment of Parapharyngeal Space Salivary Gland Tumor.

INTRODUCTION: Parapharyngeal space salivary gland tumors are very rare. The authors sought to examine the clinical features, treatment methods, and treatment results of parapharyngeal space salivary gland tumors in our hospital. METHODS: The authors retrospectively enrolled 15 patients who were finally diagnosed as having parapharyngeal space salivary gland tumors from January 2010 to January 2021. RESULTS: All parapharyngeal space salivary gland tumors arose from the prestyloid compartment. This study included 3 males and 12 females. The main symptoms were incidental diagnosis during imaging tests, followed by neck discomfort, oral mass, neck mass, and headache. Surgical methods for parapharyngeal space salivary gland tumors were performed in the following order: transcervical approach (n = 10), transcervical-parotid approach (n = 3), transoral approach (n = 1), and transparotid approach (n = 1). Pleomorphic adenoma was the most common tumor among parapharyngeal space salivary gland tumors. CONCLUSIONS: In the surgery of parapharyngeal space salivary gland tumors, a transcervical or transcervical-parotid approach was mainly used by predicting the origin site through radiologic examinations.

Resection of Parapharyngeal Space Tumors Located in the Prestyloid Compartment: Efficacy of the Cervical Approach.

BACKGROUND: Parapharyngeal space tumors are rare. Among them, tumors in the prestyloid compartment are particularly suitable for surgery; however, there are no detailed reports of such surgery and their features remain unknown. METHODS: We conducted a retrospective cohort study. For 67 surgical cases of benign tumors in this compartment, we examined the patient and tumor characteristics, fine-needle aspiration cytology (FNAC), and intraoperative details such as surgical approach, use of complete excision, and postoperative complications. RESULTS: Pleomorphic adenomas (PAs) comprised 73.1% of the lesions. The diagnostic accuracy of FNAC to differentiate benign and malignant tumors was 97.7%. Of the treated lesions, 94.0% were removed via the cervical approach alone, including all PAs. The remaining 6.0% were resected via the cervical-parotid approach. The median operative time and bleeding volume were 89 min and 50 mL, respectively. Operative time using the cervical approach was significantly shorter (p = 0.021). All cases could be treated via complete surgical excision. Postoperative complications occurred in 32.8% of patients, with transient slight facial palsy being the most common. No fatal complications occurred and 92.5% of patients had no sequelae. There was no significant association between complications and surgical approach. CONCLUSION: Based on diagnosis by FNAC, with a high accuracy rate, most benign prestyloid tumors, especially PAs, were resected using the cervical approach alone, with a shorter operative time and without severe complications.

Microbiology of parapharyngeal abscesses in adults: in search of the significant pathogens.

We aimed to describe the microbiology of parapharyngeal abscess (PPA) and point out the likely pathogens using the following principles to suggest pathogenic significance: (1) frequent recovery, (2) abundant growth, (3) growth in relative abundance to other microorganisms, (4) percentage of the isolates recovered in both absolute and relative abundance, (5) more frequent recovery in PPA pus compared with tonsillar surface and tissue. Comprehensive bacterial cultures were performed on specimens obtained from adult patients (n = 60) with surgically verified PPA, who were prospectively enrolled at five Danish ear-nose-throat departments. The prevalent isolates (in PPA pus) were unspecified anaerobes (73%), non-hemolytic streptococci (67%), Streptococcus anginosus group (SAG) (40%), Corynebacterium spp. (25%), Neisseria spp. (23%), Fusobacterium spp. (22%), Fusobacterium necrophorum (17%), Prevotella spp. (12%), and Streptococcus pyogenes (10%). The bacteria most frequently isolated in heavy (maximum) growth were unspecified anaerobes (60%), SAG (40%), F. necrophorum (23%), and Prevotella spp. (17%). The predominant microorganisms (those found in highest relative abundance) were unspecified anaerobes (53%), SAG (28%), non-hemolytic streptococci (25%), F. necrophorum (15%), S. pyogenes (10%), and Prevotella spp. (10%). Four potential pathogens were found in both heavy growth and highest relative abundance in at least 50% of cases: F. necrophorum, Prevotella spp., SAG, and S. pyogenes. SAG, Prevotella spp., F. necrophorum, S. pyogenes, and Bacteroides spp. were recovered with the same or higher frequency from PPA pus compared with tonsillar tissue and surface. Our findings suggest that SAG, F. necrophorum, Prevotella, and S. pyogenes are significant pathogens in PPA development.

First Bite Syndrome: What Neurologists Need to Know.

PURPOSE OF REVIEW: Though first bite syndrome is well known in surgical settings, it is not commonly included in the differential for sharp paroxysmal facial pain in the neurology literature. This paper will highlight the clinical features and relevant anatomy of first bite syndrome, with the goal of helping clinicians differentiate this from other similar facial pain disorders. RECENT FINDINGS: First bite syndrome is severe sharp or cramping pain in the parotid region occurring with the first bite of each meal and improving with subsequent bites. Pathophysiology has been attributed to imbalanced sympathetic/parasympathetic innervation of the parotid gland. This is seen most typically in the post-surgical setting following surgery in the parotid or parapharyngeal region, but neoplastic etiologies have also been reported. It is common for patients to present with concurrent great auricular neuropathy and/or Horner's syndrome. Evidence regarding treatment is limited to case reports/series, however, botulinum toxin injections and neuropathic medicines have been helpful in select cases. It is critical for clinicians to be able to differentiate first bite syndrome from other paroxysmal facial pain. To help with this, we have proposed diagnostic criteria for clinical assessment. Patients often improve gradually over time, but symptomatic treatment with botulinum toxin or neuropathic medicine may be required.

Surgical anatomy and nuances of the expanded transpterygoid approach to the pterygopalatine fossa and upper parapharyngeal space: a stepwise cadaveric dissection.

BACKGROUND: Superb knowledge of anatomy and techniques to remove the natural barriers preventing full access to the most lateral aspect of the skull base determines the ease of using the transpterygoid approach (ETPA) as the main gateway for all the coronal planes during endonasal surgeries. METHODS: Throughout stepwise image-guided cadaveric dissections, we describe the surgical anatomy and nuances of the ETPA to the pterygopalatine fossa (PPF) and upper parapharyngeal space (UPPS). CONCLUSION: The ETPA represents a lateral extension of the midline corridor and provides a valuable route to access the PPF/UPPS. Major landmarks for this EEA are the infraorbital canal, sphenopalatine foramen, and vidian nerve. It comprises the removal of the palatine bone, posterior wall of the maxillary sinus, and PPF transposition to drill the pterygoid process.

A case of parapharyngeal space salivary duct cyst with fine needle biopsy suspicious for squamous cell carcinoma.

OBJECTIVES: To report a unique case of salivary duct cyst presenting as parapharyngeal space mass and review relevant literature regarding salivary duct cyst and fine needle aspiration biopsy of salivary gland lesions. METHODS: After a case description, a review of the literature regarding salivary duct cyst etiology, pathophysiology, presentation, histologic features, and the accuracy of FNA in the context of salivary gland lesions was conducted. RESULTS: Salivary duct cysts are rare, often acquired, cystic dilatations of salivary ducts thought to arise secondary to ductal obstruction, commonly occurring in the major salivary glands. Fine needle aspiration is the biopsy method of choice for most head and neck lesions. There is controversy surrounding this method in salivary lesions, but recent data indicates it can be just as reliable as in other locations. CONCLUSIONS: Here, we highlight a patient with a salivary duct cyst presenting as a parapharyngeal mass, which has not been described in the literature. Overall, FNA in salivary lesions is highly pathologist dependent, which likely contributes to varying accuracy in the literature.

Tumor, host and surgery related factors predisposing to cranial nerve deficits after surgical treatment of parapharyngeal space tumors.

PROPOSE: Identification of relevant features acquired on preoperative evaluation of parapharyngeal space (PPS) tumors or related to the performed surgical approach that are predictive of the most important complication of surgical treatment of these tumors, cranial nerve palsy. METHODS: This was a retrospective analysis of 68 patients with PPS tumors treated with surgical resection in a tertiary referral center from 2009 to 2019. The preoperative clinical symptoms, age, sex, tumor size, location, histopathological type, surgical approach, radical resection, intraoperative bleeding and the occurrence of complications were collected, evaluated and compared. RESULTS: Cross-table and chi-square test results revealed that cranial nerve deficits were more common in neurogenic tumors than in other types, including malignant tumors (χ2 = 6.118, p = 0.013); the cervical approach was selected more often for neurogenic tumors (χ2 = 14.134, p < 0.001); neurogenic tumors were more frequently removed intracapsularly (χ2 = 6.424, p = 0.011); and neurogenic tumors were more likely to be located in the poststyloid area (χ2 = 17.464, p < 0.001). The two-sample t test revealed a significant correlation between age and the prevalence of cranial nerve complications (t = 2.242, p = 0.031). The mean age in the group of patients with cranial nerve palsy was 45.89 years, and that of the group without complications was 54.69 years. The results of logistic regression confirmed that the risk of nerve deficits was almost 8 times higher for neurogenic tumors (OR = 7.778, p = 0.01). None of the other analyzed variables related to tumor or surgery was significantly correlated with an increased risk of cranial nerve dysfunction. CONCLUSION: Surgical resection of tumors other than neurogenic tumors of the PPS reveals no significant risk for permanent neural dysfunction. Tumor size also had no significant effect on the risk of postoperative nerve palsy.

Primary neoplasms of the parapharyngeal space: diagnostic and therapeutic pearls and pitfalls.

PURPOSE: Parapharyngeal space neoplasms (PSNs) are rare tumors of the head and neck region. In this study, we report our institutional experience with PSNs over a 27-years period. METHODS: Patients treated between 1992 and 2018 were identified through our tumor board database. Data concerning demographics, clinical presentation, disease features, treatment, complications and follow-up were obtained retrospectively. RESULTS: In total, 48 patients were identified. Most patients had benign tumors (67.5%), with pleomorphic adenoma and schwannoma being the most frequent entities. Malignant tumors represented the remaining 32.5% of neoplasms. Concerning tissue of origin, 67.5% of neoplasms originated from salivary glands and 17.5% were neurogenic. The vast majority of PSNs required open surgical approaches (77%). The most frequent reversible and irreversible complications included paralysis of facial, vagal, and hypoglossal nerves (transient 62.5%, permanent 31.3%). Tumor recurrences occurred in 16.7% of our patients. CONCLUSION: Neoplasms of the parapharyngeal space (PPS) are rare. In our series, consistent with the literature, most patients had benign tumors. Fine-needle aspiration cytology (FNAC) and/or transoral biopsy in selected cases combined with radiographic imaging are helpful to plan the optimal approach (open/transoral) and extent of primary surgery. Close follow-up in malignant neoplasms is crucial to assess recurrence early. We present one of the largest recent studies on PPS tumors treated in a center. Given the low incidence of these tumors, our results contribute to the existing sparse evidence regarding the management and outcome of such tumors.

Comparison of Surgical Outcomes of Robotic and Conventional Approaches in Patients with Pre- and Poststyloid Parapharyngeal Space Tumors.

BACKGROUND: Benefits and drawbacks of robotic surgical approaches for parapharyngeal space (PPS) tumors remain undetermined. The purpose of this study is to compare surgical outcomes of PPS tumor patients who underwent robotic surgery with those of patients who received conventional surgical treatment. PATIENTS AND METHODS: We retrospectively analyzed clinicopathologic data from 136 patients who underwent surgical removal of PPS tumors via conventional or robotic approaches. RESULTS: We identified PPS tumors in pre- and poststyloid regions in 87 (64%) and 49 (36%) patients, respectively. There were 48 (35.3%) pleomorphic adenomas, 36 (26.5%) schwannomas, and 24 (17.6%) paragangliomas. Conventional surgical techniques were performed in 83 patients, and robotic surgical approaches were administered to 53 patients. Transcervical-parotid and transcervical approaches were most commonly performed in conventional surgery, while transoral and retroauricular approaches were the preferred surgical methods in robotic surgery for pre- and poststyloid PPS tumors, respectively. Robotic surgery resulted in less estimated blood loss during poststyloid PPS tumor surgery. Postoperative cranial nerve complications were noted in 36 of 83 cases (43.4%) in the conventional surgery group and in 17 of 53 cases (32.1%) in the robotic surgery group. Intraoperative tumor spillage of pleomorphic adenoma showed no significant differences between the two groups (13.6% in conventional vs. 15.4% in robotic surgery). The mean follow-up time was 4.9 ± 3.4 years, and recurrences were observed in two patients during follow-up without a significant difference between the two groups (4.5% in conventional vs. 3.8% in robotic surgery). CONCLUSIONS: Robotic surgery in PPS tumors is feasible through transoral, retroauricular, or combined approaches and provides treatment outcomes comparable to those of conventional open surgery.