Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture:Three case reports

BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor prognosis.Therefore,timely discovery and correct management are crucial for saving the lives of such patients and improving their prognosis.This article retrospectively analyzed the imaging and clinical data of three patients,to explore the imaging characteristics and treatment strategies for carotid artery occlusion,combined with severe skull base fractures.CASE SUMMARY This case included three patients,all male,aged 21,63,and 16 years.They underwent plain film skull computed tomography(CT)examination at the onset of their illnesses,which revealed fractures at the bases of their skulls.Ultimately,these cases were definitively diagnosed through CT angiography(CTA)examinations.The first patient did not receive surgical treatment,only anticoagulation therapy,and recovered smoothly with no residual limb dysfunction(Case 1).The other two patients both developed intracranial hypertension and underwent decompressive craniectomy.One of these patients had high intracranial pressure and significant brain swelling postoperatively,leading the family to choose to take him home(Case 2).The other patient also underwent decompressive craniectomy and recovered well postoperatively with only mild limb motor dysfunction(Case 3).We retrieved literature from PubMed on skull base fractures causing ICA occlusion to determine the imaging characteristics and treatment strategies for this type of disease.CONCLUSION For patients with cranial trauma combined with skull base fractures,it is essential to complete a CTA examination as soon as possible,to screen for blunt cerebrovascular injury.

Interobserver and intraobserver reliability of skull base angles measured on magnetic resonance images

BACKGROUND Determination of platybasia and basilar kyphosis are significant parts of routine cranial magnetic resonance(MR)interpretations.These situations may explain a patient’s symptoms or may be associated with other anomalies.AIM To indicate the interobserver and intraobserver reliability of the skull base angles(SBA)(Koenigsberg standard)and modified SBA(mSBA)measurement techniques.METHODS In total,391 patients who had undergone cranial MR imaging were re-assessed regarding the SBA measurements.The SBA and mSBA techniques were used on MR images.Two reviewers independently measured the same angles twice within a 15-day interval,using different monitors.Intraclass correlation coefficient(ICC)was calculated to reveal the intraobserver and interobserver agreements.RESULTS There was an excellent agreement between reviewers regarding both angle measurements(ICC was 0.998 for SBA and mSBA).Excellent agreement levels were also observed for intraobserver measurements.ICC was 0.998 for SBA and 0.999 for mSBA for reviewer 1.ICC was 0.997 for SBA and 0.999 for mSBA according to the measurement results of reviewer 2.Higher SBA and mSBA values were observed for females compared to males.There was no correlation between SBA and age for SBA.However,a negative and low-level correlation was observed between mSBA values and age for both reviewers.CONCLUSION SBA and mSBA measurements indicated excellent agreement regarding interobserver and intraobserver differences.The study results showed that SBA angles were reliable measurement techniques to be used on MR images.

Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture

The internal carotid artery occlusion caused by head and neck trauma,also known as traumatic intracranial artery occlusion,is relatively rare clinically.Traumatic skull base fracture is a common complication of traumatic brain injury.Traumatic skull base fracture is one of the causes of traumatic internal carotid artery occlusion.If not detected early and treated in time,the prognosis of patients is poor.This editorial makes a relevant analysis of this disease.

“In situ bone flap” combined with vascular pedicled mucous flap to reconstruction of skull base defect

BACKGROUND At present,neuroendoscopy technology has made rapid development,and great progress has been made in the operation of lesions in the saddle area of the skull base.However,the complications of cerebrospinal fluid and intracranial infection after the operation are still important and life-threatening complications,which may lead to poor prognosis.AIM To investigate the method of in situ bone flap combined with nasal septum mucosal flap for reconstruction of enlarged skull base defect by endonasal sphenoidal approach and to discuss its application effect.METHODS Clinical data of 24 patients undergoing transnasal sphenoidal endoscopic approach in the Department of Neurosurgery,Affiliated 2 Hospital of Nantong University from January 2019 to December 2022 were retrospectively analyzed.All patients underwent multi-layer reconstruction of skull base using in situ bone flap combined with nasal septum mucosa flap.The incidence of intraoperative and postoperative cerebrospinal fluid leakage and intracranial infection were analyzed,and the application effect and technical key points of in situ bone flap combined with nasal septum mucosa flap for skull base bone reconstruction were analyzed.RESULTS There were 5 cases of high flow cerebrospinal fluid(CSF)leakage and 7 cases of low flow CSF leakage.Postoperative cerebrospinal fluid leakage occurred in 2 patients(8.3%)and intracranial infection in 2 patients(8.3%),which were cured after strict bed rest,continuous drainage of lumbar cistern combined with antibiotic treatment,and no secondary surgical repair was required.The patients were followed up for 8 to 36 months after the operation,and no delayed cerebrospinal fluid leakage or intracranial infection occurred during the follow-up.Computed tomography reconstruction of skull base showed satisfactory reconstruction after surgery.CONCLUSION The use of in situ bone flap combined with vascular pedicled mucous flap to reconstruction of skull base defect after endonasal sphenoidal approach under neuroendoscopy has a lower incidence of cerebrospinal fluid leakage and lower complications,which has certain advantages and is worthy of clinical promotion.

Clinical observation of endoscopic skull base reconstruction with an anterolateral thigh free fascia flap

Objective:Radiation osteonecrosis of the skull base after radiotherapy for nasopharyngeal carcinoma is one of the most serious complications,affecting patient survival and quality of life.To date,surgical resection is the main treatment for radiation osteonecrosis.The repair after the operation is very important.Inappropriate repair or lack of repair can easily cause local infection that can even spread to the brain,aggravating osteonecrosis.This study aimed to verify the feasibility and safety of the ante-rolateral thigh free fascia flap in repairing large skull base defects.Methods:From June 2021 to July 2022,a total of 12 patients with a history of radiotherapy for naso-pharyngeal carcinoma received surgical treatment at the Department of Otolaryngology Head&Neck Surgery,Sir Run Run Shaw Hospital,Zhejiang University School of Medicine.All patients were diagnosed with radiation osteonecrosis of the skull base with large skull base defects.During the endoscopic operation,a free anterolateral thigh fascia flap was used to repair the skull base and complete vascular anastomosis reconstruction.The preoperative and postoperative pain scores were retrospectively analyzed,and the dynamic changes in endoscopic surgery sites were observed.Results:The 12 patients had a median age of 58 y,with 8(66.7%)males and 4(33.3%)females.The median headache score for the patients was 5(4-7)before surgery.The patient's headache was significantly relieved postoperatively,with 11 patients having a score of 0 and one patient having a score of 1.The stench was completely resolved after the operation.There were no serious complications during the perioperative period or 12 months after the operation.Conclusion:The application of anterolateral thigh free fascia flap in skull base reconstruction is a safe and reliable reconstruction technique suitable for endoscopic surgical repair of large-scale skull base necrosis.

Skull Base Osteomyelitis: A Rare Cause of Multiple Cranial Nerve Palsies—A Case Report from Ghana

Introduction: Skull Base Osteomyelitis (SBO) is an infectious inflammation of the skull bones that is often caused by malignant otitis externa (MOE) and affects the temporal bone. This condition commonly affects immunocompromised individuals and the elderly, particularly those with a history of diabetes mellitus. Diagnosis is challenging because of non-specific symptoms that lead to late detection and complications. This report discusses a case of SBO with multiple bilateral cranial nerve abnormalities and highlights the diagnostic and management challenges in high-risk individuals with subtle clinical signs. Case presentation: This report describes a 63-year-old patient with hypertension and diabetes who underwent surgical debridement of the left ear due to malignant otitis externa 4 months prior to presentation. The patient presented with significant dysarthria, dysphagia, ptosis of the left eye with double vision, and hearing impairment in the left ear. Examination revealed bilateral CN VI palsy, right CN VII palsy, left CN VIII palsy, and a right CN XII deficit. Initial tests were unremarkable, but a high Fungitell assay and a second review of the CT scan and MRI revealed a pathological process in the base of the skull involving bony structures and cranial nerves bilaterally, which helped diagnose SBO. The patient was subsequently discharged with oral voriconazole and continued his usual medications. The patient requested further management abroad, because he did not notice resolution of his symptoms. Surgical treatment was employed abroad to relieve his symptoms, as he recovered slowly. Conclusion: This case report underscores the importance of a multidisciplinary approach to address SBO. Collaboration between specialists in infectious diseases, otolaryngology, radiology, and neurology plays a pivotal role in achieving an accurate diagnosis and developing a tailored treatment plan. Although SBO may be infrequent, this case report highlights the need to maintain heightened clinical suspicion in high-risk individuals.

Comparison of diagnostic value of PET using 18- fluoro-2-deoxyglucose, CT and MR1 in detecting skull base invasion of nasopharyngeal carcinomas

Objective： We compared positron emission tomography （PET） using 18-fluoro-2-deoxyglucose （FDG）, enhanced computed tomography （CT） and magnetic resonance imaging （MRI） in detecting skull base invasion of nasopharyngeal carcinomas （NPC） and to evaluate the value of these three methods in determining the existence of skull base invasion of nasopharyngeal carcinomas. Methods： The images of enhanced CT, MRI and PET-CT scans, performed at intervals -〈 20 days on 57 NPC patients from July 2004 to February 2007, were selected and reviewed. The endpoints of the comparison were sensitivity, specificity, accuracy, positive predictive value （PPV） and negative predictive value （NPV） of Enhanced CT, MRI and PET-CT, based on histopathologic findings or clinical imaging follow-up for at least 6 months. Results： For detecting skull base invasion of NPC, the sensitivity of enhanced CT, MRI and PET-CT were 68.18%, 84.09%, 97.67% respectively; speci- ficity were 76.92%, 69.23%, 57.14% respectively; accuracy were 70.18%, 80.7%, 87.72% respectively; PPV were 90.9%, 90.24%, 87.5% respectively; NPV were 41.67%, 56.25%, 88.89% respectively. Conclusion： PET-CT has obvious advantages in sensitivity over CT （P 〈 0.05） and MRI, better than the two methods in accuracy and NPV and may be more valuable for new patients in detecting skull base invasion of NPC patients.

Application of CUSA Excel ultrasonic aspiration system in resection of skull base meningiomas

Background： Effective methods for managing patients with solitary pulmonary nodules（SPNs） depend critically on the predictive probability of malignancy.Methods： Between July 2009 and June 2011, data on gender, age, cancer history, tumor familial history, smoking status, tumor location, nodule size, spiculation, calcification, the tumor border, and the final pathological diagnosis were collected retrospectively from 154 surgical patients with an SPN measuring 3-30 mm. Each final diagnosis was compared with the probability calculated by three predicted models—the Mayo, VA, and Peking University（PU） models. The accuracy of each model was assessed using area under the receiver operating characteristics（ROC） and calibration curves.Results： The area under the ROC curve of the PU model [0.800; 95% confidence interval（CI）： 0.708-0.891] was higher than that of the Mayo model（0.753; 95% CI： 0.650-0.857） or VA model（0.728; 95% CI： 0.623-0.833）; however, this finding was not statistically significant. To varying degrees, calibration curves showed that all three models overestimated malignancy.Conclusions： The three predicted models have similar accuracy for prediction of SPN malignancy, although the accuracy is not sufficient. For Chinese patients, the PU model may has greater predictive power.Background： Here, we introduced our short experience on the application of a new CUSA Excel ultrasonic aspiration system, which was provided by Integra Lifesciences corporation, in skull base meningiomas resection.Methods： Ten patients with anterior, middle skull base and sphenoid ridge meningioma were operated using the CUSA Excel ultrasonic aspiration system at the Neurosurgery Department of Shanghai Huashan Hospital from August 2014 to October 2014. There were six male and four female patients, aged from 38 to 61 years old（the mean age was 48.5 years old）. Five cases with tumor located at anterior skull base, three cases with tumor on middle skull base, and two cases with tumor on sphenoid ridge.Results： All the patents received total resection of meningiomas with the help of this new tool, and the critical brain vessels and nerves were preserved during operations. All the patients recovered well after operation.Conclusions： This new CUSA Excel ultrasonic aspiration system has the advantage of preserving vital brain arteries and cranial nerves during skull base meningioma resection, which is very important for skull base tumor operations. This key step would ensure a well prognosis for patients. We hope the neurosurgeons would benefit from this kind of technique.Background： The purposes of this study were to explore the effects of high mobility group protein box 1（HMGB1） gene on the growth, proliferation, apoptosis, invasion, and metastasis of glioma cells, with an attempt to provide potential therapeutic targets for the treatment of glioma. Methods： The expressions of HMGB1 in glioma cells（U251, U-87 MG and LN-18） and one control cell line（SVG p12） were detected by real time PCR and Western blotting, respectively. Then, the effects of HMGB1 on the biological behaviors of glioma cells were detected： the expression of HMGB1 in human glioma cell lines U251 and U-87 MG were suppressed using RNAi technique, then the influences of HMGB1 on the viability, cycle, apoptosis, and invasion abilities of U251 and U-87 MG cells were analyzed using in a Transwell invasion chamber. Also, the effects of HMGB1 on the expressions of cyclin D1, Bax, Bcl-2, and MMP 9 were detected. Results： As shown by real-time PCR and Western blotting, the expression of HMGB1 significantly increased in glioma cells（U251, U-87 MG, and LN-18） in comparison with the control cell line（SVG p12）; the vitality, proliferation and invasive capabilities of U251 and U-87 MG cells in the HMGB1 siR NA-transfected group were significantly lower than those in the blank control group and negative control（NC） siR NA group（P〈0.05） but showed no significant difference between the blank control group and NC siR NA group. The percentage of apoptotic U251 and U-87 MG cells was significantly higher in the HMGB1 siR NA-transfected group than in the blank control group and NC siR NA group（P〈0.05） but was similar between the latter two groups. The HMGB1 siR NA-transfected group had significantly lower expression levels of Cyclin D1, Bcl-2, and MMP-9 protein in U251 and U-87 MG cells and significantly higher expression of Bax protein than in the blank control group and NC siR NA group（P〈0.05）; the expression profiles of cyclin D1, Bax, Bcl-2, and MMP 9 showed no significant change in both blank control group and NC siR NA group. Conclusions： HMGB1 gene may promote the proliferation and migration of glioma cells and suppress its effects of apoptosis. Inhibition of the expression of HMGB1 gene can suppress the proliferation and migration of glioma cells and promote their apoptosis. Our observations provided a new target for intervention and treatment of glioma.

Hepatocellular carcinoma metastasizing to the skull base involving multiple cranial nerves

We describe a rare case of HCV-related recurrent multiple hepatocellular carcinoma （HCC） metastasizing to the skull base involving multiple cranial nerves in a 50-year-old woman. The patient presented with symptoms of ptosis, fixation of the right eyeball, and left abducens palsy, indicating disturbances of the right oculomotor and trochlear nerves and bilateral abducens nerves. Brain contrast-enhanced computed tomography （CT） revealed an ill-defined mass with abnormal enhancement around the sella turcica. Brain magnetic resonance imaging （HR/） disclosed that the mass involved the clivus, cavernous sinus, and petrous apex. On contrast-enhanced HRI with gadolinium-chelated contrast medium, the mass showed inhomogeneous intermediate enhancement. The diagnosis of metastatic HCC to the skull base was made on the basis of neurological findings and imaging studies including CT and MRI, without histological examinations, Further studies may provide insights into various methods for diagnosing HCC metastasizing to the craniospinal area.

Transcanal endoscopic assisted skull base endolymphatic sac tumor resection: A rare disease with advanced technology

Endolymphatic sac tumors(ELSTs) are rare, papillary adenomatous tumors that arise from the endothelium of the endolymphatic sac. We demonstrate a difficult case of endolymphatic sac tumor and how it is managed via transcanal endoscopic assisted technique, with discussion of feasibility of transcanal approach to lateral skull base tumor.

THIRTY YEARS IN SKULL BASE SURGERY

The skull base generally refers to the anterior, middle and posterior cranial fossa and structures on the outside side of these skull areas. The cranial roof and skull base are separated by a line connecting the external occipital protuberance, parietal notch and supraorbital ridge[1].The skull base supports the brain above, is connected to

Exclusive endoscopic transcanal approach to lateral skull base lesions:Institutional experience of 3 cases

Introduction:Majority of petrous bone and lateral skull base pathologies are benign in nature.The complex anatomy usually warrants an extensive approach with associated morbidity.Case summary:Two cases of petrous bone cholesteatoma(1 congenital cholesteatoma with facial palsy and 1 acquired cholesteatoma)and a case of glomus tympanicum were treated with exclusive endoscopic transcanal approach.The cases of petrous cholesteatoma were addressed with trans-promontorial and infra-cochlear approaches.The mean operative time was approximately 140 min.No CSF otorrhoea was noticed in the post-operative period.The average period of hospital stay was 3.7 days.Conclusion:In the subset of cases with limited benign disease an endoscopic trans-canal approach is a better alternative to an external approach.It decreases operative time,blood loss,chance of meningitis,morbidity and hospital stay.The lack of depth perception is a major hurdle which can be come over by experience in endoscopic middle ear surgery.This approach can create direct access to cochlea/petrous apex/internal auditory canal(IAC)/Supra-geniculate ganglion region.

Supratentorial hemangioblastoma at the anterior skull base:A case report

BACKGROUND Hemangioblastoma(HB)is a rare tumor,comprising about 2%of all intracranial tumors.Although it is a benign tumor,due to the abundant blood supply and its close relationship with adjacent cerebral blood vessels,surgical resection is difficult and may cause complications such as bleeding.If HB can be correctly diagnosed before surgery,complications can be avoided by methods such as vascular embolism before surgery.CASE SUMMARY A 51-year-old male patient was admitted to our hospital because of blurred vision in his left eye for 2 years.Ophthalmological examination revealed oculus dexter vision acuity of 1.0 and oculus sinister vision acuity of 0.6.His left vision had tubular visual field,while his right vision had a partial defect.Computed tomography and magnetic resonance imaging showed a mass lesion at the left anterior base of the skull,which could have been a meningioma.During the operation,the tumor was found to be located at the entrance of the left optic nerve tube,closely adhering to the left optic nerve and the blood supply was extremely abundant.The tumor was carefully separated and diagnosed as HB postoperatively after pathological examination.CONCLUSION A rare HB at the anterior skull base could be distinguished by its imaging features,which is essential to the surgical procedures.

Transcervical Approach for Resection of Lateral Skull Base Tumors

Objectives Conventional approaches for removal of lateral skull base tumors, including transmandibular, infratemporal fossa, preauricular transzygmatic subtemporal approaches, are major invasive procedures that often sacrifice hearing and cause abnormal occlusion and cosmetic defects. Reports of the transcervical approach for resection of skull base tumors are rare, although it was described for resection of clival chordomas in as early as 1966. The purpose of this study is to review our experiences in management of lateral skull base tumors using the transcervical approach. Study Design Retrospective chart review. Methods Six lateral skull base tumor cases treated with transcervical approach procedures were reviewed, including the medical records. Results There were 4 males and 2 females. Age ranged from 12 through 52 years. Histopathological diagnoses included malignant schwannoma(n = 1), malignant carotid body tumor(n = 1), heamangioma(n=1), schwannoma (n=2) and pleomorphic adenoma (n = 1). Transcervical techniques were used in all cases with the use of microscope in the lateral skull base area. Complete tumor removal was achieved in all cases. Postoperative radiotherapy was implemented in 1 case of malignant schwannoma and 1 case of malignant carotid body tumor. Jugular foramen syndrome occurred as a surgical complication in 1 case of malignant Schwannoma of the vagus nerve. There was no tumor recurrence during the 10 - 42 month follow-up period. Conclusion Compared with conventional approaches, the transcervical approach provides a easy, safe, minimal invasive and effective procedure for removal of selected lateral skull base tumors.

Postoperative infection of the skull base surgical site due to suppurative parotitis:A case report

BACKGROUND Paraganglioma occurring at the lateral skull base is a rare tumor.Surgery is the primary treatment of benign paragangliomas.Postoperative infection of the surgical site at the lateral skull base is very dangerous and hard to manage.CASE SUMMARY A 30-year-old man with a 1-year history of left-side progressive hearing loss,tinnitus,facial palsy,and choking failed conventional treatment and is the focus of this case report.Imaging revealed a mass around the left jugular foramen that was approximately 47 mm×38 mm×34 mm in size and had eroded the bone of the vertebral and horizontal segments of the internal carotid artery.The tumor breached the meninges and occupied the cerebella pontine region.A two-stage surgery was designed for the resection of the mass.In the first-stage,the epidural portion of the mass was removed.The abdominal fat and the temporal muscle flap were transposed within the surgical site.The surgery was successful;however,25 d after surgery,he developed suppurative parotitis,and the infection spread to the surgical site at the skull base.Broad-spectrum antibiotics were used,and debridement was deployed.After that,the wound was cleaned daily.Five months after the first-stage surgery,the wound was still unclosed,and there was intermittent purulent exudation within the surgical site.vacuum sealing drainage(VSD)was used,and the wound healed in a month.One year after the first surgery,the second-stage of the operation was performed to remove the intracranial portion of the tumor.Recurrence of the tumor was not detected after a 6-month follow-up.CONCLUSION After a lateral skull base surgery,suppurative parotitis can spread into the operative cavity leading to infection of the surgical site.VSD can help to effectively heal the infected wound.A two-stage surgical approach offers a safer option for removing the lateral skull base paraganglioma that involves the meninges.

Recurrent inverted papilloma coexisted with skull base lymphoma: A case report

BACKGROUND Inverted papilloma is an uncommon neoplasm in the nasal cavity.It is a histologically benign tumor,but has a high recurrence and local invasion rate.In addition,nasal or skull base lymphoma is another rare neoplasm.The coexistence of these two tumors in one case makes the diagnosis and related treatment difficult.CASE SUMMARY We report a case of an immunocompetent patient,who had a history of inverted papilloma 20 years ago.The patient presented with an infiltrated mass lesion in the nasal cavity with extension to the frontal base.The repeated biopsies revealed inverted papilloma without any malignant transformation.After the patient underwent a frontobasal craniotomy with total tumor excision,the final pathological examination revealed nasal inverted papilloma coexisting with diffuse large B-cell lymphoma of the skull base.CONCLUSION Based on this case report,while managing a case of an aggressive recurrent inverted papilloma,not only squamous cell carcinoma transformation,but also other invasive malignancy,such as lymphoma,should be considered.

Diameters and form of skull base foramen ovale measured by three-dimensional spiral CT thin-slice scan in healthy adults

BACKGROUND： The accurate measurements of various data of the bone diameters of foramen ovale of living person can change the methods of puncturing trigeminal gasserian ganglion via foramen ovale for treating trifacial neuralgia from the experience of puncture operator only to puncture by taking the objective data of measurement as the evidence, which is good for improving the accuracy of puncturing trigeminal ganglion and reducing side effects. OBJECTIVE ： To observe the forms of foramen ovales in healthy adults displayed by volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan of skull base, and measure the longitudinal diameter and transverse diameter. DESIGN ： A repetitive observation and measurement SETTINGS ： Department of Neurosurgery and Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine. PARTICIPANTS： Fifty healthy adults （100 sides）, who were examined with three-dimensional spiral CT scan, were randomly selected from the Department of Medical Imaging, Foshan Hospital of Traditional Chinese Medicine from January 2005 to January 2006, including 26 males and 24 females, aged 25-68 years with an average of 48 years old. They were all informed and agreed with the examination. METHODS ： The subjects were examined with the Philips 16-slice spiral CT-Mx 8000 IDT CT apparatus （Philips Company, Holland）, the scanning ranged from 2 cm below the canthomeatal line to the level of suprasellar cistem. The width of collimator was 0.75 mm, pitch was 0.663; tube current was 350 mA, voltage was 120 kV, resolution was 512×512 matrix; slice thickness of reconstruction was 1 mm, and interval was 0.5 mm. After the three-dimensional spiral CT thin-slice scan of skull base, the image post-processing techniques including volume rendering and multi-planar reconstruction were applied to observe the forms of foramen ovales, and measure the size, longitudinal diameter and transverse diameter of the foramen ovales. The figures of the foramen ovales were drawn with mouse along the boundary of bone porous margin and soft tissue. According to the indications, the diameters were measured with computer to observe the forms of foramen ovales. MAIN OUTCOME MEASURES ： The longitudinal diameter, transverse diameter and form of foramen ovales were observed. RESULTS： All the 50 healthy adults （100 sides） were involved in the analysis of results. （1） It was observed in the volume rendering images that foramen ovales had four forms of oval shape （77 sides）, kidney shape （12 sides）, round shape （7 sides）, ribbon shape （4 sides）. （2） The longitudinal diameters of left and right foramen ovales were （7.67±1.32） and （7.98±1.45） mm, and the transverse diameters were （4.04±0.83）, （4.09±1.07） mm; There was no obvious difference between left and right longitudinal diameters （t = 1.63, P = 0.11 ）, and left and right transverse diameters were close （t = 0.45, P= 0.65）. CONCLUSION ： The non-invasive techniques of volume rendering and multi-planar reconstruction after three-dimensional spiral CT thin-slice scan can clearly display the formand size of foramen ovale in healthy adults.

Reconstruction of anterior skull base defects using frontalis muscle galea aponeurotica skull pedicle flaps

Objective： The aim of our study was to reconstruct soft and hard tissue perforating defects of the anterior skull base in a 1-stage surgical procedure with a combined craniofacial approach. Methods： Soft and hard tissue defects of the anterior skull base were successfully reconstructed in 43 patients during a 1-stage surgery through the use of frontalis muscle galea aponeuretica skull flaps with 1 or 2 vascularized pedicles. The skull flap areas were up approximately 7 cmx 14 cm. Results： Intracranial infection and cerebrospinal fluid leakage were not observed in the 43 patients, and all incisions healed. Of 33 malignant tumor patients, 25 patients received follow-up examinations for longer than 2 years, and 18 patients survived for 2 years. Conclusion： Frontalis muscle galea aponeurotica skull pedicle flaps provided a constant blood supply and re- suited in soft and thin tissue. The pedicle flaps, together with the external cranial bone plate, strengthened the support, but still allowed for bending and shaping. In addition, the flap harvesting approach was consistent with surgery approach, without aesthetic compromises.

Recurrent ameloblastoma in the anterior skull base: Report of 3 cases

Recurrent ameloblastoma is common following inadequate excision but rarely presents in the anterior skull base. We presented 3 patients with recurrent ameloblastoma in the anterior skull base including the frontotemporal fossa and the pterygomaxillary fossa that occurred following multiple enucleations, segmental mandibulectomy, or partial maxillectomy for ameloblastoma in the jaws. Attenborough approach was used in the exposure of the frontotemporal fossa. Attenborough plus Barbosa approach was used in the exposure of the pterygomaxillary fossa. The patients were treated by radical dissection. Microscopy confirmed that the histopathologic pattern of one case was fixed follicular and plexiform, two cases were follicular. All patients healed without serious complications. The local recurrences of the patients following the operations were found in 3 to 4 years. The present study showed that the tumors in the regions had a greater recurrence potential even when treated with radical dissection, and the original tumors were the high-risk follicular pattern.