Stereotactic radio-neurosurgery for jugular foramen schwannomas.

BACKGROUND: Stereotactic radiosurgery (SRS) represents a minimally invasive and valuable alternative for jugular foramen schwannomas (JFS), both as upfront and/or adjuvant treatment (in hybrid approaches). METHODS: We conducted a retrospective review of our cases treated at the Lausanne University Hospital (CHUV) from June 2010 to October 2023. Eleven patients underwent SRS, among whom three had prior surgery, two in our center in the frame of a planned combined approach and one in another center. Two patients received "volume-staged" SRS. The mean age at SRS was 60 years (median 68; range 29-83). Cranial nerve (CN) symptoms were present in six patients, while five were asymptomatic. The mean tumor volume at SRS was 2.1 cc (median 1.2; range 0.068-7.3 cc), with a 12 Gy marginal dose prescribed in all cases. RESULTS: The mean follow-up period was 3.9 years (median 2, range 1-7). Cranial nerve function improved after SRS in six patients, while five remained stable. At the last follow-up, all tumors showed a decrease in volume, except for one patient, who underwent surgery at 18 months after SRS, for volumetric increase at 6 and 12 months, with further XII-th CN palsy and medulla oblongata compression. Although tumor decreased at 18 months, such patient needed microsurgical resection for symptom persistence and was further controlled. The mean tumor volume at 1 year post-SRS was 1.6 cc (median 0.55; range 0.028-7.77 cc), at 2 years was 1.31 cc (median 0.76; range 0.19-5), and at 3 years was 1.32 cc (median 0.59; range 0.23-4.8). No adverse radiation events were observed. CONCLUSIONS: Stereotactic radiosurgery is considered a safe and effective treatment for jugular foramen schwannomas, ensuring high rates of tumor control in all patients over the long term. The cranial nerve function improved after SRS in the 6 patients who had deficits and the other 5 patients who had no deficits remained asymptomatic. For larger tumors, combined/hybrid approaches can be a valuable alternative, to obtain tumor control and to preserve neurological function.

[The surgical outcomes in management of jugular foramen paragangliomas with tension free anterior rerouting of the facial never and tunnel packing of the inferior petrous sinus].

Objective:The aim of this study is to evaluate the safety and efficacy of surgical interventions ofjugular foramen paragangliomas（JFP） utilizing modified surgical techniques, tensionfree anterior rerouting of the facial nerve and tunnel-packing or push-packing of the inferior petrous sinus. Methods:A retrospective analysis was conducted on a cohort of 88 patients diagnosed with JFP and treated at the Eye Ear Nose and Throat Hospital of Fudan University（in Shanghai, China） from October 2010 to June 2021. The surgical outcomes were analyzed for tumor classification, intraoperative conditions, and function of the postoperative facial nerve（FN） and lower cranial nerve（LCN）. Results:The study included a total of 88 patients, gross total resection was achieved in 70 patients（79.5%）, near total resection was obtained in 17 patients（19.3%）, and one patient undergoing subtotal resection. The average of intraoperative blood loss was 448.3 mL. Additionally, 24 patients underwent surgical total anterior rerouting（TAR）, 18 patients underwent surgical total FN tension free anterior rerouting（TF-TAR）, and 18 patients underwent surgical FN partial FN tension free anterior rerouting（TF-PAR）. Good postoperative FN function（House-Brackmann Ⅰ-Ⅱ） was achieved in 62.5% of TAR group. In the TF-TAR and PF_TAR groups, good postoperative FN function was demonstrated in 88.9% patients. It showed a significantly improvement of the FN function following application of tension-free FN anterior rerouting technique（P=0.007）. Twenty patients（22.7%） suffered from at least one LCN deficit in the preoperative evaluation. The postoperative LCN deficits was correlated with the Fisch classification of tumors, which showed a lower incidence of LCN dysfunction in classes C1-C2（4.9%, 2/41cases） and poorer outcomes of LCN dysfunction in classes C3-D（8.5%,4/47cases ）, it was likely less impacted the LCN function in the early stage tumor. Conclusion:The application of modified surgical techniques of FN tension-free anterior rerouting and tunnel-packing of the inferior petrous sinus has been shown to effectively preserve the function of the FN and LCN, decrease intraoperative blood loss, and ultimately improve patients' postoperative quality of life.

[New progress in the diagnosis and treatment of jugular paragangliomas].

Jugular paraganglioma is the most common neoplasms in the jugular foramen. It is a slow-growing wiht abundant blood supply, and is intimately associated with critical neurovascular structures at the skull base. In this paper, the latest advance in pathophysiology, surgical treatment, radiotherapy were reviewed based on previous literature, providing reference for clinical diagnosis, treatment and future research.

[Exploration of technique for preservation of external-middle ear structure in surgery of jugular foramen paraganglioma （appended 2 case reports）].

Objective:To investigate the feasibility and effect of the modified surgery of the classic infratemporal fossa type A approach for the surgical treatment of jugular foramen paraganglioma with preservation of the external and middle ear structures. Methods:The medical data of 2 patients with jugular foraminal paraganglioma treated by sublabyrinthic-transmastoid approach were retrospectively analyzed. The clinical feature, degree of tumor resection, postoperative facial nerve function and hearing retention, and the incidence of postoperative complications were evaluated. Results:Two patients were both female, and were pathologically confirmed as paraganglioma. The tumor of case 1 was staged as C2De1, and case 2 as C1De1. Tumors were completely resected in both patients. Case 1 suffered infection after surgery, with residual tympanic membrane perforation and mixed deafness. Case 2 developed mild facial paralysis（grade Ⅱ） after surgery, and recovered after symptomatic treatment. There was no tumor residue or recurrence during half a year of follow-up. Conclusion:Surgical treatment of certain paragangliomas in the jugular foramen with a combined sublabyrinthic-transmastoid and upper neck approach might achieve both complete resection of the tumor and preserving the structure and function of the outer-middle ear. This procedure is suitable for paragangliomas restricted in the jugular foramen area, with no or limited involvement of the internal carotid artery（C1 or C2）, and with no or mild hearing loss.

Post-surgical Hearing Improvement in a Case of Jugular Foramen Schwannoma Despite the Lack of Response in a Preoperative Auditory Brainstem Response Test.

We report a rare case involving improved hearing after surgery for a jugular foramen schwannoma despite the lack of response during the preoperative auditory brainstem response (ABR) test. A left jugular foramen tumor was diagnosed in a 79-year-old man with hearing loss. No response was observed during the preoperative ABR test. However, his hearing improved after surgery using the lateral suboccipital approach. Following Gamma Knife radiation to the residual tumor post-surgery, the ABR test detected V waves. The hearing of patients with cerebellopontine angle tumors can improve even when there is no response during the preoperative ABR test.

The intrabulbar or extrabulbar growth pattern and its surgical outcomes of jugular foramen paragangliomas.

OBJECTIVE: This study is to define a subclassification system of jugular foramen paragangliomas (JFPs) and to demonstrate corresponding microsurgical outcomes of JFPs. STUDY DESIGN: Retrospective study. SETTING: A single-center study. METHODS: We conducted a retrospective review of the clinical data of 44 patients with JFPs who underwent surgical management. Extrabulbar(Be) tumor and intrabulbar(Bi) tumor are defined based on the growth patterns, receiver operating characteristic (ROC) curves of the imaging profile were generated and was confirmed based on intraoperative findings. Area Under Curve (AUC), accuracy, sensitivity, and specificity for diagnostic imaging were revealed. We also compared the correlation between the two growth patterns with Fisch's classification, blood loss, lower cranial nerves (LCNs) deficit. RESULTS: There are 27 (69%) cases of Bi tumor and 17 (39%) cases of Be tumor. Significant radiomics features between the two growth patterns were demonstrated, ROC curves achieved excellent AUCs for MRI sequences (T1W1 MRI, MR contrast-enhanced sequence, MR complex sequences and MR complex + DSA by 0.833, 0.833, 0.875, 0.944) and had statistically significant in diagnosis of two growth patterns (P<0.05). There was no statistical correlation between growth patterns of JFPs and intra-operative blood loss. Preoperative LCNs deficits and Fisch's classification of tumors were correlated with the growth patterns of JFPs (P < 0.05). CONCLUSION: We proposetd two growth patterns of JFPs in term of the inferior petrous sinus involvement. Identification of Bi or Be growth patterns preoperatively is helpful to design optimal surgical strategies and minimize postoperative complications.

Surgical management of chondrosarcomas of the skull-base and temporal bone.

OBJECTIVES: To analyze the overall long-term outcome of surgically treated skull base and temporal bone chondrosarcomas. METHODS: The medical records of patients with surgically treated skull base and temporal bone chondrosarcomas between 1983 and 2024 were thoroughly evaluated. RESULTS: Out of a total of over 5000 skull base surgeries performed at our center, only 29 patients had histopathologically confirmed chondrosarcomas of the skull base and temporal bone. The mean of patients age was 45.6, and the male-to-female ratio was 1.9:1. The most common symptoms included hearing loss (58.6%), tinnitus (41.4%), diplopia (31%), dysphonia (24.1%), dysphagia (20.7%), vertigo (10.3%), and dizziness (10.3%). The most frequent locations of lesions among the 29 patients are as follows: petroclival region (34.5%), jugular foramen (27.6%), petrous apex (17.2%), middle ear (13.8%), others (3.4%). TO, IFTA, IFTB, IFTC, POTS, and combined surgical approaches were commonly used. The rate of gross total removal and recurrence was 82.6% and 13.8% respectively. The follow-up duration of 6 patients was more than five years and less than ten years whereas ten patients had more than ten years of follow-up. CONCLUSIONS: Chondrosarcoma of the skull base and temporal bone is a very rare pathology. Due to its multiple potential sites of origin and histological specificity, it presents us with significant challenges. Gross total removal is the primary treatment for chondrosarcoma of the skull base and temporal bone. Personalized decision-making should be considered based on the following aspects: tumor, patient, and surgeon's factors. Postoperative radiation therapy is complementary to surgical treatment in grades II and III lesions to achieve long-term survival.

Surgical results, technical notes and complications of jugular foramen lesions via retroauricular infratemporal fossa approach.

OBJECTIVE: The objective of this study was to evaluate the clinical effect and safety of the postauricular infratemporal fossa approach (ITFA) in resecting jugular foramen lesions. METHODS: All 25 patients undergoing microsurgery via postauricular ITFA from March 2015 to May 2023 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University were included. The clinical and radiological data were retrospectively analyzed. Regular follow-up was carried out. RESULTS: The mean age of all patients was 50.5±8.9 years, and 14 of them were female and 11 were male. Among the cases, lower cranial nerve schwannoma accounted for 60 % (15/25) of all tumors, jugular foramen paraganglioma accounted for 20 % (5/25), and the remaining 20 % included meningioma, chondrosarcoma, plasmacytoma, and salivary gland tumors. Total tumor resection was performed in 18 cases, subtotal tumor resection in 7 cases and partial resection in 1 case. Seven patients underwent gamma knife radiotherapy after surgery. Transient lower cranial nerve dysfunction occurred in 8 patients, and permanent lower cranial nerve dysfunction occurred in 2 patients after surgery. One patient developed facial paralysis, and one patient presented hearing loss. CONCLUSIONS: The postauricular ITFA achieved a relatively high total tumor resection rate and a lower incidence of neurological functional disorders. It is an alternative and suitable surgical approach for resecting jugular foramen lesions. Maximizing the preservation of neurological function is preferred, especially when radical resection cannot be achieved. Stereotactic radiotherapy could be used for residual tumors.

Friend or Foe? Preoperative Embolization in Jugular Paraganglioma Surgery-A Systematic Review and Meta-Analysis.

BACKGROUND: Jugular paragangliomas are highly vascularized tumors that can grow in challenging neurovascular compartments and are particularly challenging to resect. There is still no consensus whether preoperative embolization should be employed to minimize intraoperative morbidity. METHODS: A systematic review and meta-analysis was conducted by searching PubMed, Web of Science, and Embase databases for key terms including "embolization," "jugular paragangliomas," and "surgery." RESULTS: This review included 25 studies with 706 patients and 475 (67%) preoperative embolizations. Polyvinyl alcohol particles were the most common embolic agent (97.8% of all patients who underwent embolization). Complication rate of embolization was 1% (95% confidence interval [CI]: 0%, 2%). Preoperative embolization was significantly associated with less intraoperative estimated blood loss (mean difference of -7.92 dL [95% CI: -9.31 dL, -6.53 dL]), shorter operating room times (mean difference of -55.24 minutes [95% CI: -77.10 minutes, -33.39 minutes]), and less overall tumor recurrence (odds ratio = 0.23 [95% CI: 0.06, 0.91]) compared with resective surgery alone. Preoperative embolization had no impact on the development of postoperative new cranial nerve deficits not associated with embolization (odds ratio = 1.17 [95% CI: 0.47, 2.91]) and achievement of gross total resection (odds ratio = 1.92 [95% CI: 0.67, 5.53]). CONCLUSIONS: Preoperative embolization may provide surgical efficiency with faster surgical times and less bleeding and safety with diminished overall recurrence via safe embolization with minimal risks. These results must be considered taking into account the nonrandomness of studies.

Microsurgical resection of a samii type D jugular foramen schwannoma via the carotid triangle without removal of bony structure: how I do it.

BACKGROUND: Samii Type-D jugular foramen schwannomas (JFSs) are the most challenging for neurosurgeons because of anatomical complexity. Various neurosurgical approaches have been described to gain access to JF. METHODS: We present a female with incidental diagnosis of the Type-D JFS. Complete radical resection was achieved via the carotid triangle approach without any bony structure removal. And the patient was discharged asymptomatic and without new-developed neurological deficits. CONCLUSIONS: The carotid triangle is a secure and appropriate approach for some cases of selected Type-D JFSs. However, the specific indications of this approach should be further explored and investigated.

Are Chiari Malformation and Basilar Invagination Associated with Jugular Foramen Stenosis?

OBJECTIVE: We compared the diameter of the jugular foramen (JF) between normal individuals and those with a diagnosis of craniovertebral junction abnormalities, such as Chiari malformation type I (CMI) and/or basilar invagination (BI). METHODS: This cross-sectional analytical study measured the diameter of the right and left JF on magnetic resonance imaging scans of patients divided into 4 groups: 68 with combined CMI and BI (CMI+BI), 42 with isolated BI, 45 with isolated CMI, and 102 control cases. The t test determined sex differences, and univariate analysis of variance with Tukey's post hoc test assessed JF differences between groups. RESULTS: Considering all combinations of laterality and sex, the CMI+BI group had a JF narrower than their respective control groups. The JF was bilaterally narrower in the BI group than in the control group only in the women. Regardless of laterality, the CMI group had a wider JF than did the CMI+BI group in men and did not differ from that of the control group. In the female patients with CMI, the right JF did not differ from that of the controls and was wider than that in the CMI+BI group. Also, the left JF was narrower than that in the control group and did not differ from that in the CMI+BI group. CONCLUSIONS: JF narrowing is associated with CMI and BI when combined in the same patient. When CMI or BI are detected separately, they do not imply evident changes in JF morphometry. It is expected that these findings could bring empiric substrate to support theories that claim a possible role of intracranial pressure disturbances as a triggering factor for CMI.

Jugular Foramen Paragangliomas.

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery.

Collet-Sicard syndrome caused by a paraganglioma in the region of the jugular foramen on one side: A case report and review.

Collet-Sicard syndrome is a rare neurological disorder caused by injury to the cranial nerve pairs IX, X, X, and XII. The author reports on a previously fit 27-year-old man who presented with dysphagia, choking on drinking water, hoarseness, weakness when turning the neck and shrugging the shoulders, and unexplained weight loss. Enhanced magnetic resonance imaging indicated a space-occupying lesion at the right jugular foramen. After surgical resection, the pathologic findings suggested a paraganglioma of the right jugular foramen and confirmed the diagnosis of Collet-Sicard syndrome. After postoperative treatment with a combination of acupuncture and modern medicine, the patient's symptoms significantly improved. This article analyzes previous literature regarding Collet-Sicard syndrome etiology and reports the case of a patient with a rare etiology, whose prognosis improved significantly after treatment with a combination of acupuncture and modern medicine.

Jugular foramen stenosis in external hydrocephalus in infants.

OBJECTIVE: To measure the size of jugular foramina in infants affected by external hydrocephalus (EH) and in a control group, to support the hypothesis that a jugular foramen (JF) stenosis may determine dural venous sinus alterations and increased venous outflow resistance as main pathophysiological factor. METHODS: Minimum, maximum, and mean values of JF areas were measured in a series of phase-contrast magnetic resonance venous angiography (angio MRV PCA3D) performed on 81 infants affected by EH. Results were compared with a group of 54 controls. RESULTS: Smaller JF area was significantly smaller in patients versus controls (43.1 ± 14.6 vs. 52.7 ± 17.8; p < 0.001) resulting in a significantly smaller mean JF areas in patients vs. controls (51.6 ± 15.8 vs. 57.0 ± 18.3; p = 0.043). In patients, smaller JF areas were significantly associated with higher venous obstruction grading score (VOGS) both on the right (p = 0.018) and on the left side (p = 0.005). Positional plagiocephaly (cranial vault asymmetry index > 3.5%) was more frequent among EH patients than controls (38/17) but the difference was not significant (p = 0.07). In the 38 plagiocephalic patients, JF area was smaller on the flattened side than the contralateral in a significant number of cases both in right (21/7) and left (9/1) plagiocephaly (p < 0.0005) as well as the mean area (48.2 + 16.4 mm2 vs. 57.5 + 20.7 mm2, p = 0.002) and VOGS was significantly higher on the plagiocephalic side than on the contralateral side (1.6 ± 1.1 vs. 1.1 ± 0.9, p = 0.019). CONCLUSION: In this series of infants affected by EH, the mean size of the ostium of both JF resulted significantly smaller than controls. JF stenosis was significantly associated with higher degrees of venous obstruction on both sides, suggesting a direct extrinsic effect of JF size on dural sinus lumen and possible consequent effect on venous outflow resistance. Positional plagiocephaly, when present, was associated with a decreased JF area and increased VOGS on the flattened side.

[Analysis of the effect of different facial nerve managements applied to tumor resection in the jugular foramen region].

Objective:To summarize the results of different facial nerve management modalities applied to tumor resection in the jugular foramen region. Methods:The clinical data of 54 patients with tumors in the jugular foramen region who underwent surgery from January 2015 to March 2023 were retrospectively analyzed: 18 males and 36 females; Age ranges from 21 to 67 years, with an average age of 44.4 years; and median follow-up time: 12 months. The House-Brackmann（HB） grading system was applied to assess the patients' facial nerve function before surgery, 1-2 weeks after surgery and at the final follow-up （HBⅠ-Ⅱ grade for good function）: 42 cases with preoperative HB grades Ⅰ-Ⅱ; partial facial nerve transposition（9 cases）, complete facial nerve transposition（28 cases）, and facial nerve excision and re-construction（17 cases） were used, respectively（stage Ⅰor Ⅱ）. Relevant factors affecting postoperative facial nerve function were analyzed. Results:Postoperative pathology confirmed 39 cases of paraganglioma, 9 cases of nerve sheath tumor, 3 cases of meningioma, and 1 case each of fibromucinous sarcoma, chondrosarcoma, and intravascular myofibroma. Facial nerve function after partial facial nerve transposition was HB grade Ⅰ-Ⅱ in 89%（8/9）; after complete facial nerve transposition was HB grade Ⅰ-Ⅱ in 86%（24/28） in 28 cases; after facial nerve severance and reconstruction was HB grade Ⅰ-Ⅱ in 2/7（Stage Ⅰ） and 0/3（Stage Ⅱ）, respectively. Tumor size and surgical approach were correlated with postoperative facial nerve function in patients with facial nerve transposition（P<0.05）. There was no statistically significant difference in facial nerve function after complete and partial facial nerve transposition（P>0.05）. Conclusion:Intraoperative stretching of the facial nerve may be an important factor affecting facial nerve function during surgical treatment of tumors in the jugular venous foramen region; for patients with facial nerve dissection, facial nerve reconstruction should be adopted according to the situation, aiming at the recovery of facial nerve function.

Computed tomographic features of canine intracranial and jugular foraminal masses involving the combined glossopharyngeal, vagus, and accessory nerve roots.

A chronic cough, gag, or retch is a common presenting clinical complaint in dogs. Those refractory to conservative management frequently undergo further diagnostic tests to investigate the cause, including CT examination of their head, neck, and thorax for detailed morphological assessment of their respiratory and upper gastrointestinal tract. This case series describes five patients with CT characteristics consistent with an intracranial and jugular foraminal mass of the combined glossopharyngeal (IX), vagus (X), and accessory (XI) cranial nerves and secondary features consistent with their paresis. The consistent primary CT characteristics included an intracranial, extra-axial, cerebellomedullary angle, and jugular foraminal soft tissue attenuating, strongly enhancing mass (5/5). Secondary characteristics included smooth widening of the bony jugular foramen (5/5), mild hyperostosis of the petrous temporal bone (3/5), isolated severe atrophy of the ipsilateral sternocephalic, cleidocephalic, and trapezius muscles (5/5), atrophy of the ipsilateral thyroarytenoideus and cricoarytenoideus muscles of the vocal fold (5/5), and an ipsilateral "dropped" shoulder (4/5). Positional variation of the patient in CT under general anesthesia made the "dropped" shoulder of equivocal significance. The reported clinical signs and secondary CT features reflect a unilateral paresis of the combined cranial nerves (IX, X, and XI) and are consistent with jugular foramen syndrome/Vernet's syndrome reported in humans. The authors believe this condition is likely chronically underdiagnosed without CT examination, and this case series should enable earlier CT diagnosis in future cases.

Morphological analysis of the jugular foramen in dry human skulls in northeastern Brazil.

The jugular foramen (JF) is located between the temporal and occipital bones. The JF is a primary pathway for venous outflow from the skull and passage of nerves. Variations are common in this region and may have clinical and surgical implications. To analyze the sexual dimorphism and JF morphology in skulls from Northeastern Brazil. 128 human skulls from the Anatomy Laboratory of the Federal University of Paraíba, 64 male and 64 female, were selected and the JFs analyzed for bone septation and the presence of a dome. Data analysis considered P<0.05 as significant. On at least one side, complete septation was observed in 26 skulls (20.3%), incomplete septation in 93 skulls (72.6%) and 61 skulls (47.6%) did not present septation. In 114 skulls (89%), 47.6% female and 41.4% male, have a unilateral presence of the dome and 71 (55.4%) have it bilaterally. Posterolateral compartment diameters and JF area had higher values on the right side in the total sample and separated by sex (P<0.05). Most morphometric variables of the anteromedial compartment were higher in male than in female (P<0.05), fact that was not observed in the posterolateral compartment (P>0.05). This study showed a higher prevalence of complete septation in males compared to females. Morphometric analysis presented a peculiar morphology of the JF in this study. These results suggests that the surgical approach to diseases that affect the JF may be peculiar to the studied population, confirming the importance of morphological analysis of the skull base.

Determination of the radioanatomical factors related to the position of facial nerve in accessing jugular foramen and carotid artery in temporal bone.

Introduction: Preservation of the facial nerve is of great importance in temporal bone surgeries. We intend to investigate the measurements of the radioanatomical factors related to the position of the facial nerve in accessing jugular foramen and internal carotid artery (ICA) in temporal bone of patients who were candidates for temporal high resolution computed tomography (HRCT) scan. Methods: In this correlation cross-sectional study, samples were selected from patients referred to Amir Alam Hospital who were previously candidates for temporal HRCT. Radioanatomic factors were evaluated in three axial, coronal and sagittal views. Analyzes were performed using descriptive statistics, correlation analysis and factor analysis. Results: A total of 173 samples were investigated. The most reliable radioanatomical factor based on coefficient of variation (CV) was the distance of the 7th nerve to the temporomandibular joint (TMJ) in the inferior to the cochlea in the sagittal view (variable name S2) (CV = 8.1%) and then the distance from the 7th nerve to the TMJ in the inferior section of the cochlea in the axial view (variable name AI3) (CV = 8.4%). Based on correlation analysis and then confirmatory factor analysis, three common latent factors were identified (overall R2 = 0.999). Conclusion: The results of this study can be used for two purposes. First, the direct use of the estimated measures in surgical operations, and the second is more advanced modeling to choose the approach in the surgical operation and how to implement that approach. For the first aim, the two factors AI3 and S2 were the most reliable radioanatomical factors in different people. For the second aim, the three-dimensional understanding of the obtained measurements and the further identification of the anatomical nature of the latent factors can help in choosing the approach in surgery.

Microsurgical anatomy of the glossopharyngeal nerve.

The glossopharyngeal nerve is a complicated and mixed nerve including sensory, motor, parasympathetic, and visceral fibers. It mediates taste, salivation, and swallowing. The low cranial nerves, including IXth, Xth, and XIth, are closely related, sharing some nuclei in the brainstem. The glossopharyngeal nerve arises from the spinal trigeminal nucleus and tract, solitary tract and nucleus, nucleus ambiguous, and inferior salivatory nucleus in the brainstem. There are communicating branches forming a neural anastomotic network between low cranial nerves. Comprehensive knowledge of the anatomy of the glossopharyngeal nerve is crucial for performing surgical procedures without significant complications. This review describes the microsurgical anatomy of the glossopharyngeal nerve and illustrates some pictures involving the glossopharyngeal nerve and its connective and neurovascular structures.

Investigating the Effects of Trigeminal Impression and Internal Acoustic Opening Morphology Differences for Possible Surgical Applications.

PURPOSE: The exhaustive information regarding the types of trigeminal pore (TP) or trigeminal impression (TI), internal acoustic opening (IAO), and related surgical approaches is lacking in the literature. Therefore, this study is performed to further elucidate the types of TP or TI, IAO, and the relationships with critical surgical landmarks in the skull base. METHODS: Trigeminal impression (TI) and internal acoustic opening (IAO) found in 11 dry skulls, 24 right temporal bones, and 25 left temporal bones were examined on both sides to define their relationship to each other and nearby structures. The age and sex of these bones were not identified. Besides these, 77 skulls were examined by radiologic imaging methods. These skulls were identified by gender. RESULTS: According to test results, there was a significant difference between the left and right internal acoustic opening in the case of horizontal dimension (HD). The left HD-IAO is bigger than the right one. In addition, right HD-IAO, vertical dimension (VD) of right internal acoustic opening, left HD-IAO, and left VD-IAO values differed significantly in male and female patients. CONCLUSIONS: Investigating the relationship of TI and IAO with relevant structures suggests that surgical approaches involving the TP and IAO indicated that surgical approaches considering the TI and IAO variations may be used in the development of surgical processes and primary surgical interventions.