Neurological Complications in Benign Parapharyngeal Space Tumors – Systematic Review and Meta-Analysis

Abstract

Introduction Parapharyngeal space tumors with complex anatomy and diverse histology have remained a challenging phenomenon for treating physicians.

Objectives We have conducted a comprehensive web search on the PubMed, Web of Science, EMBASE, Cochrane Library, Biomedical Literature Database (CBM), and Clinicaltrials.gov databases to determine the factors that are associated with postoperative complications in parapharyngeal space tumors.

Data Synthesis Two researchers reviewed all identified articles independently with a third reviewer for adjudication. Patient demographics and other clinicopathological characteristics were explored. The systematic review has identified 631 benign parapharyngeal space tumors with neurogenic and salivary tissue histology in 13 studies, with a mean age of 42.9 ± 7.76 years old and a median follow-up of 40.98 ± 19.1 months. Salivary gland (50.8%) and neurogenic (49.1%) tumors were the most common histological entities. Tumor size, location, histology, deep parotid lobe involvement, and proximity to great vessels or to the skull base were the deciding factors in selecting the surgical approach. The factors considered to select the surgical approach do not seem to have a correlation with the outcome in terms of neurological sequalae (p = 0.106). Tumors with neurogenic histology have significantly increased chances of developing neurological complication (OR 6.07; p = 0.001).

Conclusion Neurologic complications are significantly associated with neurogenic benign tumors rather than surgical approach.

Keywords

cancer of head and neck - parapharyngeal space - neurologic manifestations

Introduction

The parapharyngeal space (PPS) is an imaginary inverted pyramidal space with an extension from the skull base to the hyoid bone divided by the Riolan bundle into pre- and poststyloid compartments.[1] [2] [3] Of all head and neck cancers, PPS tumors account for 0.5% and most of them are benign (80%), with diverse histology. Pleomorphic adenoma is the most common benign tumor of salivary gland origin occupying mostly the prestyloid compartment, and schwannomas are the most common neurogenic entities residing in the poststyloid space.[4] The correct histopathological diagnosis of these lesions may not be achieved due to their complex anatomical location, relying more on image findings (computed tomography [CT], magnetic resonance imaging [MRI], or angiography) for preliminary diagnosis. This may also help in identifying the anatomical extent of the growth.[1] Surgery has remained as the primary treatment modality if not contraindicated by gross intracranial tumor extension or by comorbidities pushing toward other nonsurgical treatment options.[5] A lot of literature including case series and reports has been published regarding PPS tumors with diverse benign and malignant histology, including all the deep lobe parotid, infratemporal fossa tumors, as well as carotid body paragangliomas that, by definition, may not fall into the precise anatomical parapharyngeal space. Accurately placing these lesions into the true PPS may have clinical implication in terms of choosing the right surgical approach.[6] The systematic reviews published for PPS lesions have already mentioned this issue and have presented the recent updates on presentation, histological diagnosis, surgical approaches, and complications. We have aimed our study more on the surgical approaches for the resection of benign PPS tumors and associated neurologic sequelae. A thorough search was conducted by reviewing all the available relevant published data to focus on the rationale behind the selection of different surgical approaches and associated neurological complications.

Review of the Literature

Literature Search for Data Collection

We have performed an extensive search in the PubMed, Cochrane Library, Web of Science, EMBASE, Biomedical Literature Database (CBM), and Clinicaltrials.gov databases with reference to PPS tumors. Articles fulfilling the search criteria with keywords such as parapharyngeal space or transmandibular or benign parapharyngeal space tumor or trans-cervical or lip split mandibulotomy or mandibular swing were included in the first instance and the search was concluded on May 25, 2019. The analysis included systematic reviews, retrospective studies, and literature reviews pertaining to open surgical management of primary parapharyngeal space tumors published from 1989 to 2019. No publication focused on the management of benign parapharyngeal space tumors was found due to the rarity of the disease. The studies with management of PPS tumors including series with ≥ 10 patients were also incorporated. Data was collected including age and gender of the patients, year of publication, histopathological classification, surgical approaches, and complications. The exclusion criteria were case reports /series addressing malignant pathology only, treatment modalities other than surgery, single-case reports or case series with < 5 patients, nonprimary PPS tumors, tumors with nasopharyngeal, intracranial, or infratemporal fossa extensions, studies comparing approaches such as robotic/lateral skull, studies that provide data using single modality with no comparisons, letters to the editors, meeting abstracts, and editorials.

Robotic and endoscopic approaches have not been included in the review as most of the published literature have addressed PPS tumors with open surgical access. Furthermore, the endoscopic approaches may still need to be validated for reproducibility and effectiveness to be labeled as the standard of care. We had to incorporate different benign histologies since the numbers are very small and the surgical management of these tumors has been based more on the location of the tumor rather than on the tissue of origin.

Data Extraction

Data extraction and quality assessment of all included studies were independently performed by 2 authors (Faisal M. and Erovic B. M.). Controversies were solved by discussion or by consultation with another author (Seeman R.). Basic information such as patient demographics, histopathology, presenting complaints, surgical approaches, and postoperative complications were recorded. All included papers were clinical studies focusing on the surgical management of PPS tumors using different approaches and their postoperative complications or sequelae. The present study did not require approval and was granted exemption from the Ethical Review Board of the Evangelical Hospital, Vienna, Austria, and of the Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan.

Data Analysis and Statistical Methods

IBM SPSS Statistics for Windows, version 25 (IBM Corp., Armonk, NY, USA) was used for statistical analysis. The independent t-test was used to compare the means of two normally distributed groups (salivary versus neurogenic tumors). The Pearson correlation coefficient was calculated to determine the correlation between the tissue of origin of the tumor and postoperative complications. Binary logistic regression analysis was performed to measure the odds of having neurological complications in salivary and neurogenic PPS tumors. A p-value < 0.05 was considered statistically significant. GraphPad Prism 8 (GraphPad Software, San Diego, CA, USA) was used to draw the bar charts.

Search Findings

A total of 2,674 articles were identified with the database search using keywords as mentioned in the methodology section. 1,852 articles remained after removal of duplicates. Next, the articles were screened by title and abstract reading to select the relevant studies, and 745 remained in this step. The short case series reporting < 5 patients were further excluded. After full-text revision, 679 articles were excluded for reasons described in the Plasma flowchart. Hence, 13 studies, all published in English, with a total of 631 participants, were included for further evaluation.[6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the study selection procedure was illustrated by the PRISMA flow diagram ([Fig. 1]). Three studies were conducted in USA, two in Spain, two in China, and one each in Egypt, India, Israel, Brazil, Italy, and Japan.[6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] A total of 631 patients were recruited from studies published between 1996 and 2017.

Fig. 1 Flow diagram; the flow diagram was adapted according to the PRISMA recommendations.

Study Cohort

There were 631 patients with benign histology (either salivary or neurogenic in origin). The mean age at presentation was 42.9 ± 7.76 years old, with a median follow-up of 40.98 ± 19.1 months. Baseline characteristics and demographics along with presenting complaints, histological variation, and complications of cumulative data have been further expressed ([Table 1]). The patients were categorized into 2 groups based on the tissue of origin, such as neurogenic (n = 310) and salivary (321) and were subsequently compared based on subsequent complications. The primary surgical approaches used were (i) transcervical (60%), (ii) cervicoparotid (30%) including dissection and exposure of the facial nerve trunk and associated branches, and (iii) transmandibular (10%) comprising mandible split for access and tumor resection ([Fig. 2]). The transcervical approach was favored in 9 out of 13 studies compared with 4 studies in which the cervicoparotid access was used. None of the studies has given clear preference to the use of the transmandibular approach. The most common neurogenic tumor found was schwannoma (54%) followed by paraganglioma (43%) ([Fig. 2]). The distribution of complications based on salivary or neurogenic histology has been represented for all the studies included in the review.

Fig. 2 Distribution of parapharyngeal space tumors based on surgical approach and tumor histology.

Table 1 Demographics and baseline characteristics of cumulative studies

Author	Year of publication	Country	Sample size (n)	Mean age (years old)	M:F ratio*	Presenting complaints	Mean follow-up (months)
Cohen et al.	2005	USA	89	47	2.3:1	No symptom 25.3%	28
Attia et al.	2004	Egypt	8	37	1:1.9	Neck swelling 72%	21
Miller et el.	1996	USA	37	48	1:1	Pharyngeal mass 45%	35
Hazarkia et al.	2004	India	38	33	1.5:1	Neck swelling 53.5%	39
Zhi et al.	2008	China	113	36	1.3:1	Neck swelling 72.8%	36
Malone et al.	2001	USA	18	53	1:1.9	Not mentioned	24
Khafif et al.	2005	Israel	31	46	1:1.6	Not mentioned	35
Tincani et al.	1999	Brazil	16	53	2.2:1	Pharyngeal mass 68%	60
Cassoni et al.	2014	Italy	49	38	1:1.4	Pharyngeal mass 68.3%	91
Iglesias et al.	2015	Spain	28	42	1:1.5	Pharyngeal mass 71%	48
Ijichi et al.	2017	Japan	26	43	1:2.1	Neck swelling 34.4%	29
Shi et al.	2017	China	130	45	1:1	Pharyngeal/Neck swelling 55%	45
Grili et al.	2017	Spain	58	47	1:1	Pharyngeal mass 26%	Not mentioned

Abbreviations: F, female; M, male.

The 148 patients with neurogenic complication among 310 neurogenic tumors (mean: 11.38; standard deviation [SD]: 11.81) were compared against 41 patients with neurological complication among 321 salivary gland tumors and demonstrated a significantly increased rate of nerve-related complications (t = 2.42; p < 0.05). Among the neurologic complications, the most encountered were vocal cords palsy (73%), Horner syndrome (9%), hypoglossal nerve injury (6%), and first bite syndrome (4%) ([Table 2]).

Table 2 Determinants of selection of surgical approaches in cumulative studies

Author	Size	Location	Proximity to great vessels	Proximity to the skull base	Histology	Parotid lobe involvement
Cohen et al.[7]	No	No	Yes	Yes	No	Yes
Attia et al.[8]	Yes	Yes	Yes	No	Yes	No
Miller et el.[9]	Yes	Yes	Yes	No	Yes	No
Hazarkia et al.[10]	No	No	Yes	Yes	Yes	Yes
Zhi et al.[11]	Yes	Yes	Yes	No	Yes	No
Malone et al.[12]	No	No	No	No	Yes	No
Khafif et al.[13]	Yes	No	Yes	No	Yes	No
Tincani et al.[14]	No	Yes	No	No	Yes	No
Cassoni et al.[15]	No	No	No	No	Yes	Yes
Iglesias et al.[16]	Yes	Yes	Yes	No	Yes	No
Ijichi et al.[17]	Yes	Yes	No	No	Yes	No
Shi et al.[18]	Yes	Yes	Yes	Yes	Yes	No
Grili et al.[6]	Yes	Yes	Yes	No	Yes	No

The factors considered for selecting surgical approaches in 13 studies on PPS tumors were categorized into size, location, histology, proximity to greater vessels or to the base of skull, histology, and deep parotid lobe involvement ([Table 3]). Each factor was given a score and the combined scores were compared with the percentage of complications to assess if any of these factors considered before surgery would have an effect in the outcome in terms of complication rates. The correlation coefficient suggested a small degree of positive correlation that is not statistically significant (p = 0.930). The tissue of origin (neurogenic versus salivary) seems to have a positive correlation with more complications related to neurogenic tumors (Pearson coefficient: 0.662; p = 0.019) ([Fig. 3]). The binary logistic regression showed a significantly increased likelihood of developing postoperative neurological complications in tumors with neurogenic histology (p = 0.0001) ([Table 2]). We performed a meta-analysis assessing neurological complications among the groups with both salivary and neurogenic tissues of origin. Due to a heterogeneity < 50%, a fixed term model was used. Neurological deficit was observed in 48% of patients with neurogenic histology (148/310), while only 13% of the patients with salivary tumor developed neurological deficit. The pooled relative risk (RR) was 2.41 (95% confidence interval [CI]: 1.80–3.23; p = 0.001) ([Fig. 4]).

Fig. 3 Comparison of complication rates based on tissue of origin in PPS tumors. Note: Pearson correlation = 0.686; p = 0.019.

Fig. 4 Meta-analysis – Neurogenic histology and risk of neurogenic complications.

Table 3 Complications of surgical removal of neurogenic tumors

Neurological complications	n	%
VC paralysis	109	73
Hoarseness	5	3.3
Hypoglossal nerve injury	10	6.7
Horner syndrome	14	9.39
First bite syndrome	6	4
Pharyngoparalysis	2	1.3
CN V palsy	3	2
Total	149
	Univariate Analysis
Variable	OR	p-value	95%CI
Histology (N versus S)	6.0	0.001	4.083–9.026

Abbreviations: CI, confidence interval; CN, cranial nerve; N, neurogenic; OR, odds ratio; S, salivary; VC, vocal cords.

Quality of Studies

The risk of bias of the included works has been assessed in eight categories using the ACROBAT-NRSI tool recommended by the Cochrane group and an overall score was calculated indicating the quality of each analyzed study ([Table 4]).

Table 4 Quality of included studies using ACROBAT-NRSI* version 10

Assessment of bias	Selection of population	Assessment of exposure	Outcome of interest	Match with prognostic variables	Assessment of prognostic factors	Assessment of outcome	Adequate follow up	Cointervention between groups	Overall score
Cohen et al.[7]	Low risk	Medium	Low risk	Medium risk	Low risk	Low risk	Low risk	High risk	Medium
Attia et al.[8]	Low risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	Low risk	Medium
Miller et el.[9]	Low risk	Low risk	Low risk	High risk	Low risk	Low risk	Low risk	High risk	High
Hazarkia et al.[10]	Low risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	High risk	Medium
Zhi et al.[11]	Medium risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	High risk	Medium
Malone et al.[12]	Low risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	Medium risk	Medium
Khafif et al.[13]	Low risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	Medium risk	Medium
Tincani et al.[14]	Low risk	Low risk	Low risk	High risk	Low risk	Low risk	High risk	High risk	High
Cassoni et al.[15]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Medium risk	Medium
Iglesias et al.[16]	Medium risk	Low risk	Low risk	High risk	Low risk	Low risk	Low risk	Medium risk	Medium
Ijichi et al.[17]	Low risk	Low risk	Low risk	Medium risk	Low risk	Low risk	Low risk	Medium risk	Medium
Shi et al.[18]	Low risk	Low risk	Low risk	High risk	Low risk	Low risk	Low risk	High risk	Medium
Grili et al.[6]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk	Medium risk	Medium

*A Cochrane risk of bias assessment tool for nonrandomized studies of interventions.

Discussion

Benign tumors are the most common entity (80–90%) found in the PPS, with the parotid gland as the most common site of origin.[19] [20] [21] The PPS is divided into two compartments by an osteomuscular aponeurotic sheath originating at the styloid process. The prestyloid space contains components such as the deep lobe of the parotid gland, fat and lymphatic nodes, inferior, lingual, and temporal auricular alveolar nerves. The retrostyloid space encloses neurovascular structures such as the carotid artery, the jugular vein, the cervical sympathetic chain, and cranial nerves IX, X, XI, and XII, suggesting a more diverse histology from this compartment.[22] Parapharyngeal space tumors must be clearly identified, since erroneous anatomical boundaries may have resulted in the inclusion of adjacent tumors in some of the published literature, such as deep lobe tumors, which should only be considered if the location is retromandibular. Similarly, lesions at the foramen ovale must be a part of infratemporal fossa tumors while carotid body paragangliomas below the posterior digastric body must not be considered a part of PPS tumors.[23] Due to their complex anatomical location and diverse histology, precise approaches to PPS tumors have remained a controversial debate.[24] [25] Complete excision with minimal morbidity should be the aim of the operating surgeon, particularly when dealing with benign PPS tumors. Size, location (pre- or poststyloid), proximity to the skull base and to the vascular bundle, extension to the deep lobe of the parotid, and imaging-based position (superior/middle/inferior) of the lesions are some of the key factors considered preoperatively to select a surgical approach.[7] [13] [15]

The inclusion of mandibulotomy has raised many concerns, such as facial scar, orocervical fistula, prolonged operating time, malocclusion, trismus, delay in resuming regular diet, risk of exposure of the fixation plate, and temporomandibular joint (TMJ) dysfunction.[26] [27] [28] The most used approach to access PPS tumors published in the literature was the transcervical, either alone or in combinations. In the cumulative series of 631 patients, this approach has been utilized for 60% of cases, addressing both salivary and extraparotid neurogenic tumors. The facial nerve may not need to be exposed to further extend the dissection and exposure. Due to excessive push and pull, neuropraxia may occur in the postoperative setting. The identification of the facial nerve may increase the access to large-sized and superiorly-placed PPS tumors. The rationale behind the use of the transcervical approach in our cumulative search was small (preferably < 8cm), benign, prestyloid extraparotid tumors in the lower PPS. Further exposure can be achieved by division of posterior belly of the digastric muscle and removal of the submandibular gland on occasion.

The cervicoparotid approach uses formal identification of the facial nerve trunk and is indicated for tumors in proximity to the deep lobe of the parotid gland with risk of adherence to the facial nerve. The transcervical approach only may jeopardize the preservation of the facial nerve. In our cumulative results, it is the second most used approach, which is in line with previously published data, in which the most commonly used indications for the cervicoparotid access were large, pre- or retrostyloid, deep lobe parotid, or minor salivary gland tumors, as well as neurogenic tumors with or without facial nerve involvement located in the middle to lower PPS but not involving the base of skull. Access may be further enhanced by prognathic mandibular dislocation dividing the stylomandibular ligament and the styloid muscle.

The transmandibular approach with its modifications (midline/paramedian or lateral splits) is usually performed for massive, large vascular or recurrent benign tumors placed more superiorly in the PPS. In the cumulative series, the transmandibular approach was only used in 6% of the patients, especially due to the large size of the tumors (mostly > 8cm), to the vascular nature of the tumor, to superior location of the tumor in the PPS, and to proximity of the tumor to the skull base. The use of the transmandibular approach has been further limited as indicated by recent studies showing a decline in the use of the transmandibular approach (from 9 to 6%) when compared with previous reports.[29] [30] [31] Prolonged hospital stay, delay in resuming normal diet, tracheostomy covering, trismus, and associated TMJ and occlusal disturbances are some of the drawbacks of this technique.[32] [33]

The cumulative studies in our cohort have depicted a significantly high number of neurogenic complications in both salivary and neurogenic tumors. Detailed analysis has shown these complications to be more common in tumors with neurogenic tissue of origin. The literature has described 5 major histological subtypes of neurogenic tumors with > 90% presenting benign histology. Batsakis and Sneige[22] have reported paraganglioma to be the most common subtype, while John et al. and Danke et al. have found schwannomas to be the most commonly found histological entity.[34] [35] Schwannomas arise usually from cranial nerves IX to XII or from the cervical sympathetic chain, with decreased risk of nerve injury when small. On the other hand, paragangliomas derive from the vagal nerve with a potential for intracranial extension or malignant transformation. The list of complications in our combined series included vocal cord paralysis (73%), Horner syndrome (9.3%), hypoglossal nerve injury (6.7%), and first bite syndrome (4%). The tumors with salivary histology had a complication rate of 12.8%, which is significantly lower than that of neurogenic tumors (47.7%) (t value = 2.42; p = 0.023). This preemptive assessment of the anticipated range of neurologic complications must be considered to educate the patients on the postoperative sequelae and, simultaneously, prepare them to facilitate rehabilitation.

Our systematic analysis may have its share of limiting factors. Most of the studies included are retrospective series with inherent biases for the selection of surgical approaches, clinical expertise, and intraoperative and postoperative care, with a variable support for postoperative rehabilitation. Most studies have omitted data on some critical factors when applying these surgical approaches, such as length of hospital stay, cost effectiveness, return to normal diet or oral feeding in the transmandibular approach, infection, time to healing, and length of the surgery.

Final Comments

Most PPS tumors are benign (80%), with either neurogenic or vascular origin. With < 0.5% of the tumors arising from the deep parotid lobe, the transcervical approach may be an appropriate solution for these benign PPS tumors with less morbidity and complications. Cranial nerve deficits are the result of complications arising from the neurogenic tissue, irrespective of which surgical approach is used.

Conflict of Interests

The authors have no conflict of interests to declare.

• References

• 1 Metgudmath RB, Metgudmath AR, Malur PR, Metgudmath VV, Das AT. Surgical management of parapharyngeal space tumors: our experience. Indian J Otolaryngol Head Neck Surg 2013; 65 (Suppl 1): 64-68
• 2 Bradley PJ, Bradley PT, Olsen KD. Update on the management of parapharyngeal tumours. Curr Opin Otolaryngol Head Neck Surg 2011; 19 (02) 92-98
• 3 Olsen KD. Tumors and surgery of the parapharyngeal space. Laryngoscope 1994; 104 (5 Pt 2, Suppl 63) 1-28
• 4 Singh M, Gupta SC, Singla A. Our experiences with parapharyngeal space tumors and systematic review of the literature. Indian J Otolaryngol Head Neck Surg 2009; 61 (02) 112-119
• 5 Luna-Ortiz K, Navarrete-Alemán JE, Granados-García M, Herrera-Gómez A. Primary parapharyngeal space tumors in a Mexican cancer center. Otolaryngol Head Neck Surg 2005; 132 (04) 587-591
• 6 Grilli G, Suarez V, Muñoz MG, Costales M, Llorente JL. Parapharyngeal space primary tumours. Tumores primarios del espacio parafaríngeo. Acta Otorrinolaringol Esp (Engl Ed) 2017; 68 (03) 138-144
• 7 Cohen SM, Burkey BB, Netterville JL. Surgical management of parapharyngeal space masses. Head Neck 2005; 27 (08) 669-675
• 8 Attia A, El-Shafiey M, El-Shazly S, Shouman T, Zaky I. Management of parapharyngeal space tumors at the National Cancer Institute, Egypt. J Egypt Natl Canc Inst 2004; 16 (01) 34-42
• 9 Miller FR, Wanamaker JR, Lavertu P, Wood BG. Magnetic resonance imaging and the management of parapharyngeal space tumors. Head Neck 1996; 18 (01) 67-77
• 10 Hazarika P, Dipak RN, Parul P, Kailesh P. Surgical access to parapharyngeal space tumours–the Manipal experience. Med J Malaysia 2004; 59 (03) 323-329
• 11 Zhi K, Ren W, Zhou H, Wen Y, Zhang Y. Management of parapharyngeal-space tumors. J Oral Maxillofac Surg 2009; 67 (06) 1239-1244
• 12 Malone JP, Agrawal A, Schuller DE. Safety and efficacy of transcervical resection of parapharyngeal space neoplasms. Ann Otol Rhinol Laryngol 2001; 110 (12) 1093-1098
• 13 Khafif A, Segev Y, Kaplan DM, Gil Z, Fliss DM. Surgical management of parapharyngeal space tumors: a 10-year review. Otolaryngol Head Neck Surg 2005; 132 (03) 401-406
• 14 Tincani AJ, Martins AS, Altemani A. et al. Parapharyngeal space tumors: considerations in 26 cases. Sao Paulo Med J 1999; 117 (01) 34-37
• 15 Cassoni A, Terenzi V, Della Monaca M. et al. Parapharyngeal space benign tumours: our experience. J Craniomaxillofac Surg 2014; 42 (02) 101-105
• 16 Iglesias-Moreno MC, López-Salcedo MA, Gómez-Serrano M, Gimeno-Hernández J, Poch-Broto J. Parapharyngeal space tumors: Fifty-one cases managed in a single tertiary care center. Acta Otolaryngol 2016; 136 (03) 298-303
• 17 Ijichi K, Murakami S. Surgical treatment of parapharyngeal space tumors: A report of 29 cases. Oncol Lett 2017; 14 (03) 3249-3254
• 18 Shi X, Tao L, Li X. et al. Surgical management of primary parapharyngeal space tumors: a 10-year review. Acta Otolaryngol 2017; 137 (06) 656-661
• 19 Hughes III KV, Olsen KD, McCaffrey TV. Parapharyngeal space neoplasms. Head Neck 1995; 17 (02) 124-130
• 20 Carrau RL, Myers EN, Johnson JT. Management of tumors arising in the parapharyngeal space. Laryngoscope 1990; 100 (06) 583-589
• 21 Lukšić I, Virag M, Manojlović S, Macan D. Salivary gland tumours: 25 years of experience from a single institution in Croatia. J Craniomaxillofac Surg 2012; 40 (03) e75-e81
• 22 Batsakis JG, Sneige N. Parapharyngeal and retropharyngeal space diseases. Ann Otol Rhinol Laryngol 1989; 98 (4 Pt 1): 320-321
• 23 Curtin HD. Separation of the masticator space from the parapharyngeal space. Radiology 1987; 163 (01) 195-204
• 24 Scheithauer MO, Bohn JC, Riechelmann H. [Median sagittal mandibulotomy in head-neck tumors]. Laryngorhinootologie 2000; 79 (08) 490-497
• 25 Gooris PJ, Worthington P, Evans JR. Mandibulotomy: a surgical approach to oral and pharyngeal lesions. Int J Oral Maxillofac Surg 1989; 18 (06) 359-364
• 26 Li W, Li R, Safdar J. et al. Modified visor approach applied to total or subtotal glossectomy and reconstruction: avoidance of lip splitting and mandibulotomy and cutting off mental nerve. Tumour Biol 2014; 35 (08) 7847-7852
• 27 Eisen MD, Weinstein GS, Chalian A. et al. Morbidity after midline mandibulotomy and radiation therapy. Am J Otolaryngol 2000; 21 (05) 312-317
• 28 El-Zohairy MA. Straight midline mandibulotomy: technique and results of treatment. J Egypt Natl Canc Inst 2007; 19 (04) 292-298
• 29 Riffat F, Dwivedi RC, Palme C, Fish B, Jani P. A systematic review of 1143 parapharyngeal space tumors reported over 20 years. Oral Oncol 2014; 50 (05) 421-430
• 30 Kuet ML, Kasbekar AV, Masterson L, Jani P. Management of tumors arising from the parapharyngeal space: A systematic review of 1,293 cases reported over 25 years. Laryngoscope 2015; 125 (06) 1372-1381
• 31 Sheahan P. Transcervical approach for removal of benign parapharyngeal space tumors. Operative Techniques in Otolaryngology-Head and Neck Surgery 2014; Sep 1; 25 (03) 227-233
• 32 Abdel-Haleem A, El Sayed A, Hakeem HA. Transmandibular approach in parapharyngeal tumors; when to do it?. Egypt J Ear Nose Throat Allied Sci 2011; 12: 25-31
• 33 Chu F, Tagliabue M, Giugliano G, Calabrese L, Preda L, Ansarin M. From transmandibular to transoral robotic approach for parapharyngeal space tumors. Am J Otolaryngol 2017; 38 (04) 375-379
• 34 John DG, Carlin WV, Brown MJ. Tumours of the parapharyngeal space. J R Coll Surg Edinb 1988; 33 (02) 56-60
• 35 Dankle SK. Neoplasms of the parapharyngeal space. Ear Nose Throat J 1987; 66 (12) 491-501

Publikationsverlauf

Eingereicht: 10. Februar 2021

Angenommen: 16. Juni 2021

Artikel online veröffentlicht:
21. Oktober 2022