Surgical Treatment of Primary Parapharyngeal Space Tumors: A Single-Institution Review of 28 Cases

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.

Management of Parapharyngeal Space Tumors: Clinical Experience with a Large Sample and Review of the Literature

Parapharyngeal space (PPS) tumors are rare, and they account for 0.5-1.5% of all head and neck tumors. This study summarized the findings of large-sample clinical studies of PPS tumors and reported the clinical work-up and management of 177 cases of PPS tumors at our center. This retrospective study included patients treated for PPS tumors between 2005 and 2020 at our center. The basic characteristics, symptoms, surgical approach, complications, and recurrence rates were analyzed. A total of 99 male and 78 female patients, with a mean age of 48.3 ± 15.1 years, were enrolled in this study. The most common symptoms were external or intraoral masses (114 patients, 64%). Surgical management leveraging, a cervical approach, was used for 131 cases (74%). The tumors were benign for 92% (160 cases), with pleomorphic adenoma being the most common (88 cases, 50%). Surgical complications were reported for 31 cases (18%); facial and vocal cord paralyses were the most common. Three cases of recurrence were observed during the follow-up. PPS tumors are rare and present with atypical clinical manifestations. The current study, which involved cases in a large single center, demonstrates the importance of surgical interventions for PPS tumors. The use of endoscopic techniques has further expanded the scope of traditional surgical approaches and demonstrated its advantages in selected cases.

A Retrospective Analysis on the Effects and Complications of Endoscope-Assisted Transoral Approach and Lateral Cervical Approach in the Resection of Parapharyngeal Space Tumors

Objective

To observe and compare the effects and complications of endoscope-assisted transoral approach and lateral cervical approach in the resection of parapharyngeal space (PSS) tumors.

Methods

From January 2013 to September 2021, 69 patients with parapharyngeal space tumors in the Affiliated Hospital of Jiangnan University were divided into the control group (n = 37) and the observation group (n = 32) according to the mode of operation. The tumors in the parapharyngeal space were resected by the lateral cervical approach in the control group, and the tumors in the parapharyngeal space were removed by endoscopy-assisted transoral approach in the observation group. The general clinical data and operation conditions of the two groups, including operative blood loss, operation time, drainage volume and drainage time, hospital stay, perioperative pain degree, and tumor resection rate were collected and analyzed statistically. The patients were followed up for 6 months, and the complications of the two groups were recorded.

Results

Compared with the control group, the operation time in the observation group was significantly shorter, and the amount of intraoperative bleeding in the observation group was significantly less than that in the control group, and the difference was statistically significant (P < 0.05). The postoperative drainage was less and the hospital stay in the observation group was shorter than that in the control group, and the difference was statistically significant (P < 0.05). There was no significant difference in tumor resection rate between the two groups. The visual analog scale (VAS) score on the 1st and 3rd day after operation in the observation group was lower than that in the control group. After treatment, some patients in the two groups had complications such as nerve injury, dysphagia, difficulty in mouth opening, massive hemorrhage, and parotid fistula. The total incidence of complications in the observation group was lower than that in the control group, and the difference was statistically significant (P < 0.05).

Conclusions

The effect of the endoscope-assisted transoral approach is similar to that of the lateral cervical approach in the resection of tumors in parapharyngeal space, but the endoscope-assisted transoral approach has shorter operation time, less intraoperative bleeding, and less postoperative drainage. The indwelling time and hospital stay of the drainage device were shorter than those of the patients with transcervical approach, and the perioperative stress response of patients with endoscope-assisted transoral approach is mild, which is beneficial to the physical and mental recovery of the patients.

Surgical approaches for pleomorphic adenoma of the parapharyngeal space

OBJECTIVE

This study aimed to analyse the outcomes of surgery for pleomorphic adenoma of the parapharyngeal space in relation to the surgical approach.

METHOD

This was a single-centre retrospective data analysis conducted from January 2008 to December 2020 on all patients who underwent operation for pleomorphic adenoma originating from the parapharyngeal space.

RESULTS

Twenty-one patients with a mean age of 52.6 years were included. The transparotid-transcervical approach was the most common (52.4 per cent, n = 11) surgical approach, followed by transoral robotic surgery (28.6 per cent, n = 6) and conventional transoral surgery (19 per cent, n = 4). Post-operative complications included nine cases of transient partial facial nerve palsy and two cases of Frey's syndrome after the transparotid-transcervical approach and 2 cases of transient trismus and 1 pharyngeal wound dehiscence in the conventional transoral approach group. Complete macroscopic excision was always achieved, and no recurrence occurred during follow up.

CONCLUSION

These three approaches can provide adequate tumour visualisation, a high rate of clear excisional margins and an acceptable morbidity.

Transoral Endoscopic Localization of the Parapharyngeal Internal Carotid Artery

Objectives  To define transoral endoscopic surgical landmarks for the parapharyngeal segment of the internal carotid artery (ppICA) using cadaveric dissection. Methods  Ten fresh cadaveric heads were dissected to demonstrate the parapharyngeal space anatomy and course of the ppICA as seen in a transoral approach. Anatomical measurements of the distance between the ppICA and bony landmarks were recorded and analyzed. Results  The stylohyoid ligament, styloglossus, and stylopharyngeus could be considered to be the safe anterior boundary of the ppICA in the transoral approach; among them, the styloid ligament was the most rigid tissue. Dissection between the stylopharyngeus muscle and superior pharyngeal constrictor muscle provides direct access to the ppICA. At the level of the skull base, the distance from the root of the styloid process to the lateral margin of the external aperture of the carotid canal on the left side and on the right side was 8.57 ± 1.97 and 8.80 ± 1.21 mm, respectively. At the level of the maxillary tuberosity, the distance from the ppICA to the maxillary tuberosity on the left side and on the right side was 31.48 ± 2.24 and 31.01 ± 2.88 mm, respectively. Conclusion  The endoscopic-assisted transoral approach can facilitate exposure of the ppICA. The root of the styloid process, styloid ligament, and maxillary tuberosity are critical landmarks in the identification of the ppICA in the transoral approach.

Surgical Management of Parapharyngeal Tumors: Our Experience

Context Tumors of parapharyngeal space (PPS) are rare and histologically diverse. The management of these tumors requires diligent assessment and planning with due consideration of various anatomical and pathological aspects of the lesion.

Aims This retrospective study aims to present our experiences in the clinical and pathological aspects of PPS tumors with a critical evaluation of management.

Settings and Design Retrospective analytical study.

Methods and Material The electronic medical records of 60 cases of PPS tumors, managed surgically from 2007 to 2017, were reviewed and analyzed using SPSS 22 software. The mean follow-up duration was 44 months.

Results The mean age was 45 years with a male-to-female ratio of 1.7 (38:22). The majority of the tumors were benign (71.7%) and the most common presentation being upper neck mass or oropharyngeal mass. Histologically, neurogenic tumors were most common (43.3%) PPS tumors, followed by tumors of salivary gland origin. Magnetic resonance imaging was used as a diagnostic modality in 70% of cases, and computed tomography scan and positron emission tomography/CT were used in 26.7 and 3.3% of cases, respectively. In our study, the diagnostic accuracy of fine-needle aspiration cytology was 71% for benign and 47% for malignant lesions. The most common approach for surgery used was transcervical (72%).

Conclusion The study reveals that cranial nerve palsy is the most common complication associated with PPS tumors. Completely resected, malignant tumors originating within PPS have a good prognosis, as compared with tumors extending or metastasized to PPS.

The development of a clinical algorithm for the diagnosis of tumours in the parapharyngeal space. A systematic review

INTRODUCTION

Parapharyngeal space (PPS) is defined as a deep space, located around the upper pharynx, in the shape of an inverted pyramid. Primary tumours in this region are rare, accounting for 0.5% of head and neck neoplasms, and most are benign. The objective of this study is to propose a new study algorithm based on a systematic review and our experience.

MATERIALS AND METHODS

A cross-sectional and analytical study was carried out through review of the clinical records of our hospital. Patients with tumours of the parapharyngeal space operated from January 2010 to December 2019 and a systematic review of Pubmed studies from the last 5years were included. We considered clinical signs, diagnostic methods, presumptive diagnosis and histopathological findings. Statistical analysis was performed with STATA v.14 software.

RESULTS

53 of our cases and 1392 from the review were included. The clinical algorithm showed a sensitivity of 76.4% and a specificity of 96.3%, with an AUC of 0.57 for diagnosis.

DISCUSSION

Complementary radiological examinations are essential in the topographic diagnosis of the tumour. Angio-MRI links the tissue of origin of the tumours and provides the highest diagnostic certainty. FNA has some disadvantages in PPS, but it is useful in some patients.

CONCLUSION

The proposed algorithm contributes to obtaining excellent results in the management of these tumours because it turned out to be effective in diagnosis, and this enables improved surgical planning.

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.

Transoral Excision of Parapharyngeal Tumors

OBJECTIVES

The transoral approach for parapharyngeal space tumors has been criticized due to its restrictive exposure and increased rate of vascular and nerve injuries. However, for certain tumors-namely those that are prestyloid, benign, and well-encapsulated-the transoral approach reduces overall morbidity while providing direct access. Transoral surgeons can rely on this approach for select tumors seen clearly on intraoral examination in the bulging lateral pharynx. In this article and with a supplemental operative technique video, we demonstrate our transoral approach in these select patients.

METHODS

We reviewed our 26 cases using this approach and chose a representative case of a 50-year-old man who presented with a large, prestyloid, encapsulated parapharyngeal mass affecting his voice and swallowing. A transoral approach to the parapharyngeal tumor is illustrated.

RESULTS

A vertical curvilinear incision is completed from the hamulus to below the inferior extent of the tumor. Blunt dissection of the tumor capsule proceeds inferiorly. Controlled violation of the tumor capsule can aid in visualization. After tumor delivery, the wound is irrigated and closed.

CONCLUSIONS

In our experience, the transoral approach is an effective method to access well-encapsulated, prestyloid parapharyngeal space tumors. Patient selection is important when considering a transoral approach.