Radiologic analysis of the location, shape and size of the external aperture of the carotid canal in children.

OBJECTIVES: This retrospective computed tomography (CT) study was aimed to assess the growth dynamic of the external aperture of the carotid canal (EACC) in children aged between 1 and 20 years. METHODS: Two hundred patients (sex 100 females/100 males, average age 10.50 ± 5.77 years) with good head CT image quality were included in this study. CT images of the patients were used to obtain data related to the location, shape and dimension of EACC. RESULTS: EACC shapes were identified as oval shaped, round shaped, and tear-drop shaped in 58.3% (233 sides), 24% (96 sides) and 17.8% (71 sides), respectively. EACC length, disEACC-MSP (distance between EACC and midsagittal plane), and EACC width did not change from the prepubescence period; while, the disEACC-SC (distance between EACC and supramastoid crest) seemed to reach adult size in the postpubescence period. Linear functions for EACC length and width were calculated as: y = 5.453 + 0.091 × years, and y = 5.398 + 0.059 × years, respectively. CONCLUSION: The regression equations of the measured parameters representing the growth dynamic of EACC in children can be helpful to estimate its size, location and angulation, which suggest that the dimension and distances to certain anatomical landmarks seemed to reach adult size in different developmental periods. In this context, the findings of this study may seem to emphasize the importance of preoperative radiological evaluation on skull base, related to EACC, for multidisciplinary surgeon teams during childhood surgeries in terms of patients' positioning, and the selection of appropriate surgical approach.

Vascular malformation of the sphenoid and temporal bone: A diagnostic dilemma.

We present a rare case of a vascular anomaly of the sphenoid and temporal bones causing an expandable mass of the temporal region with dependent patient positioning and characteristic osseous changes on imaging. Initial diagnosis considerations included multiple myeloma (MM), fibrous dysplasia (FD), Paget's disease, lymphoma, meningoencephalocele (MEC), and vascular malformation (VaM). VaMs of the head and neck are rare and typically arise in the mandible and maxilla. However, this case demonstrates a unique finding of a VaM of the sphenoid and temporal bones with important radiological features to distinguish the diagnosis of vascular anomaly from other etiologies.

Landmarks for the preservation of the middle temporal artery during mastoid surgery: Cadaveric dissection study.

IMPORTANCE: The middle temporal artery flap is a vascularized periosteal flap that is highly useful for otologic reconstruction including the middle cranial fossa, mastoidectomy defect, and external auditory canal. The course of the artery is close to the external auditory canal and is easily injured during preliminary exposure and elevation of flaps. OBJECTIVES: To describe the course of the middle temporal artery in relation to the external auditory canal and the superficial temporal artery in order to enhance preservation and use in otologic reconstruction. DESIGN: Dissection of preserved, injected cadaveric temporal bones. SETTING: Anatomical laboratory. PARTICIPANTS: Seven cadaveric temporal bones. INTERVENTION: Temporal bones were dissected in a planar manner to identify the middle temporal artery along the squamous temporal bone to its origin. The superior border of the external auditory canal was divided, horizontally, into thirds to create three measurement points. Distances between the middle temporal artery and the bony portion of the external auditory canal were then determined. MAIN OUTCOMES AND MEASURES: Horizontal diameter of the external auditory canal, distance from the superior-most border of the external auditory canal to the middle temporal artery, various patterns of the middle temporal artery. RESULTS: The middle temporal artery branched from the superficial temporal artery in all specimens. Mean horizontal diameter of the external auditory canal was 9.97mm. Mean distances between the bony portion of the external auditory canal and middle temporal artery for the first, second, and third points along the horizontal diameter of the external auditory canal were 1.57, 2.96, and 4.02mm, respectively. In at least one specimen, the artery dipped into the external auditory canal. CONCLUSIONS AND RELEVANCE: The middle temporal artery runs closest to the external auditory canal at the anterosuperior border. To preserve the middle temporal artery for use in reconstruction after otologic surgery, the surgeon should avoid dissection superior to the external auditory canal until the artery is positively identified.

The relationship between tinnitus and vascular anomalies on temporal bone CT scan: a retrospective case control study.

INTRODUCTION: Tinnitus is a common symptom in which etiology is unclear in a group of patients. Some of anatomic or vascular variations diagnosed on temporal bone computed tomography (CT) has been known to cause tinnitus particulary pulsatile form. Therefore significance of these anatomic variations has not been validated in patients with nonpulsatile tinnitus. The aim of this study is to ascertain several anatomic variations previously attributed to pulsatile tinnitus in nonpulsatile tinnitus patients. And secondly to assess the relationship between the amount of sigmoid sinus bulging and mastoid emissary vein (MEV), enlargement of those was not evaluated before in tinnitus patients. METHODS: Retrospectively, temporal bone CT scans of 70 patients with an existing complaint of tinnitus with unexplained etiology were enrolled. As a control group, 70 patients were selected from paranasal sinus CT scans without any otological or clinical findings. RESULTS: The type of tinnitus was subjective and nonpulsatile in the overall group. The diameters of enlarged MEV on the left side were significantly higher in the tinnitus group. Carotid canal dehiscence and high riding jugular bulb were significantly higher in the tinnitus patients. Petrous bone pneumatization was significantly lower in the tinnitus patients than in the control group. CONCLUSIONS: In patients who complained of subjective nonpulsatile tinnitus with unknown etiology, some temporal bone vascular variations, including high riding jugular bulb, dehiscent carotid canal, left-sided MEV enlargement, and petrous bone pneumatization, seemed to have an association with tinnitus. Further studies comparing all these entities between pulsatile and nonpulsatile groups and healthy controls should be undertaken.

Morphology, topography and clinical signi cance of the jugular foramen.

The paper describes morphological variants of the jugular foramen of the human skull and discusses the reasons for its frequent asymmetry. Bilateral disproportions between the anteroposterior and mediolateral diameters of the jugular foramina were analyzed. We established that the jugular foramen is extremely narrow when its anteroposterior diameter is less than 5.0 mm. When the mediolateral diameter exceeds 20.0 mm, then the foramen exhibits extreme widening.

Clinical implications of the middle temporal vein with regard to temporal fossa augmentation.

BACKGROUND: The middle temporal vein (MTV) traverses the temporal fossa between the superficial and deep layers of the deep temporal fascia. During filler injection into a deficient temporal fossa, filling agents may be inadvertently injected into the MTV, which results in vascular complications. OBJECTIVE: To investigate the course of the MTV to enable safe filler injection in the temple area. MATERIALS AND MATERIALS: The course and diameter of the MTV were measured in 18 hemifaces from 9 Korean cadavers. RESULTS: The MTV was located 23.5 and 18.5 mm above the zygomatic arch at the jugale and the zygion, respectively. The diameter of the MTV at its thickest point was 5.1 mm. A splitting and reuniting pattern, such that the MTV occupied more space than a single trunk, was observed in 28% of cases. CONCLUSION: We propose that the safest area for filler injection in temporal fossa augmentation is one finger width above the zygomatic arch.

Anatomic study of the distance between the articular eminence and foramen spinosum and foramen spinosum and petrotympanic fissure.

PURPOSE: The middle meningeal artery is in close proximity to the medial aspect of the temporomandibular joint (TMJ). A major potential complication of surgery in the area of the TMJ is possible severance of the middle meningeal artery. An understanding of the relationship of the middle meningeal artery to easily identifiable landmarks lateral to the TMJ can help prevent the complications associated with TMJ surgery. The aim of the present study was to define the location of the middle meningeal artery by relating the distance between the easily identifiable bony landmarks of the articular eminence, petrotympanic fissure, and foramen spinosum. MATERIALS AND METHODS: Using a cross-sectional study design, we selected dried skulls from the Hamman-Todd skeleton collection at the Cleveland Museum of Natural History that were older than 20 years of age at death. The primary study variables were the distances between the articular eminence and foramen spinosum and the foramen spinosum and petrotympanic fissure. To appropriately analyze the variables, stratifications of age, gender, race, and anatomic location were applied. To measure the relationship between the stratifications and distances, a multivariate analysis of variance test was performed. The statistical results were deemed significant at P < .05. RESULTS: The sample consisted of 354 skulls or a total of 708 complexes. In analyzing the data, we noted that the only stratifications that bore any statistical significance were gender, with P < .0001, and the race-distance correlation, with a P value of .0007. CONCLUSIONS: The results of the present study suggest a definite difference in regard to gender on the distance between both sets of anatomic landmarks. Future studies could be tailored to further explore the effect of age on the distance, as a slight correlation was noted in our study.

The graft kinking of high-flow bypass for internal carotid artery aneurysm due to elongated styloid process: a case report.

Elongated styloid process is an often-caused symptom due to the compression of neighboring structures. We present a case of a graft kink of high-flow bypass due to an elongated styloid process and describe the technical pitfalls encountered when creating a graft route from the standpoint of the anatomical site.

The neglected emissary vein in mastoidectomy; persistent petrosquamosal sinus in the laterally located sigmoid sinus.

The emissary veins are residual connections between intracranial venous sinuses and their extracranial drainage, which if not diagnosed preoperatively could be a cause of severe hemorrhage at the time of surgery which may be life threatening. The petrosquamosal emissary sinus (PSS) which is a rare embryonic emissary vein along the petrosquamosal fissure of the temporal bone connects dural sinuses with external jugular venous system. The PSS has been known to regress during fetal and early postnatal life. The imaging diagnosis of the PSS has been rarely reported in humans. We report the presence of the PSS with laterally located sigmoid sinus in patient with chronic otitis media. Our hope is that this report will be useful to the otologist during surgery.

Subarcuate artery and canal: an important anatomic variant.

An aberrant subarcuate artery and its related canal are rare. The presence of this variation has a surgical significance, that is, risk of hemorrhage, if accidentally nicked. It is therefore important to be aware of this entity, and its relative anatomy, to avoid any untoward complication. We present a case of a 29-year-old man who presented with hearing loss after trauma. High-resolution computed tomographic scan of the temporal bone demonstrated an enlarged subarcuate canal.

Transosseous Veins of the Temporal Bone: Connection Between Middle and Posterior Cranial Fossa Venous Structures.

BACKGROUND: The veins and dural venous sinuses of the skull base are important to understand in terms of imaging findings, diagnoses, and surgery. However, to date and to the best of our knowledge, the transosseous veins of the petrous part of the temporal bone have not been studied. METHODS: Ten latex-injected adult cadaveric specimens (20 sides) were dissected to identify the intraosseous and transosseous veins. The petrous part of the temporal bone was drilled away, and the petrous part of the internal carotid artery and the veins of the middle and posterior cranial fossa adjacent to the petrous part of the temporal bone were exposed. RESULTS: Transosseous veins traveling through the petrous part of the temporal bone were identified on all 20 sides. In general, these were most concentrated near the anterior and posterior parts of the petrous part of the temporal bone. Most traveled more or less vertically from the petrous ridge and related superior petrosal sinus internally through the petrous part of the temporal bone toward the inferior petrosal sinus or horizontally, uniting the veins of the floor of the middle cranial fossa with the veins of the posterior cranial fossa. These transosseous veins connected the veins in the middle cranial fossa with the veins of the posterior cranial fossa. Most (70%) of these transosseous veins were also found to have small connections to the internal carotid venous plexus. CONCLUSIONS: To the best of our knowledge, previous studies have not reported on transosseous veins of the temporal bone or described their anatomy of connecting the veins of the middle and posterior cranial fossae.

Treatment of venous pulsatile tinnitus by compression reconstruction of sigmoid sinus.

BACKGROUND: Surgical intervention can effectively treat venous pulsatile tinnitus. AIM/OBJECTIVES: To assess the effectiveness of treating of venous pulsatile tinnitus (VPT) by compression reconstruction of sigmoid sinus (SSCR) under local anesthesia. MATERIAL AND METHODS: This study retrospectively reviewed 41 patients with VPT in our otolaryngology department between September 2009 and February 2019. Under local anesthesia, all patients were received SSCR. Pre- and postoperative Tinnitus Handicap Inventory (THI) degree and scores were used to evaluate the efficacy of SSCR for VPT. RESULTS: Of the 41 patients, 36 patients were followed up from 9 months to 8 years and 5 patients were lost to follow-up and were excluded from the data analysis. SSCR was clinically effective in 86% of patients with complete disappearance in 18 patients (50%), partial remission in 10 patients (28%), slight alleviation in 3 patients (8%), and no change in 5 patients (14%). The pre- and postoperative THI degree and scores were significantly different (p < .001 and p = .002, respectively). CONCLUSIONS AND SIGNIFICANCE: SSCR under local anesthesia is effective for treating patients with VPT. It is critical to perform a rigorous pre-operative clinical and radiological evaluation to reduce intra- and postoperative complications.

Subarcuate canal and artery: a case report.

Variations in the course of the subarcuate artery (SAA) and of its related funnel are infrequent and asymptomatic. We present a case of a 15-year-old girl with a preverbal severe bilateral hearing loss and a subarcuate canal with an unusual course and atypical correlation with the adjacent anatomical structures, particularly with the lateral semicircular canal and the facial nerve. The variation proposed in this case, not previously reported in the literature consulted, can have important implications during middle ear surgical procedures, particularly for the retro-facial tympanoplasty approach: in fact otologic surgeons should consider any kind of variation of the SAA in surgical planning to avoid unexpected hemorrhages. The CT-scan, particularly HRCT, is a very useful tool for the study of intrapetrous vessels and their funnels, and should be considered mandatory in the case of a posterior approach to the tympanic cavity.

Modification of three-dimensional prototype temporal bone model for training in skull-base surgery.

Experience with dissection of the temporal bone is essential for training in skull-base surgery, but only a limited number of neurosurgical residents have the opportunity of cadaver dissection. A modification of a commercially available prototype three-dimensional (3D) temporal bone model is proposed to include artificial dura mater, venous sinuses, and cranial nerves for such surgical training. The base 3D temporal bone model incorporates the surface details and the inner ear structures and air cells. Model dural sinuses and dura mater made from silicone, cranial nerves made from rubber fibers, and internal carotid artery made from rubber tubes were added to the model. Posterior petrosectomy (transpetrosal approach) and transcondylar approach were performed on this model using a high-speed drill and ultrasonic bone curette under an operating microscope. The modified 3D temporal bone model provided good experience with the complicated 3D anatomy. The model could be dissected, and the dural sinuses and dura mater preserved by the eggshell peeling technique in almost the same way as real temporal bone. The modified 3D temporal bone model provides a good educational tool for training in skull-base surgery.

The diploic venous system: surgical anatomy and neurosurgical implications.

OBJECT: There are few systematic investigations of the dissected surgical anatomy of the diploic venous system (DVS) in the neuroanatomical literature. The authors describe the DVS relative to different common neurosurgical approaches. Knowledge of this system can help avoid potential sources of unacceptable bleeding and may impact healing of the cranium. METHODS: Using a high-speed drill with a 2-mm bit, the authors removed the outer layer of the compact bone in the skull to expose the DVS in 12 formalin-fixed cadaver heads. Pterional, supraorbital, and modified orbitozygomatic craniotomies were performed to delineate the relationship of the DVS. RESULTS: The draining point of the frontal diploic vein (FDV) was located near the supraorbital notch. The draining point of the anterior temporal diploic vein (ATDV) was located in all pterional areas; the draining point of the posterior temporal diploic vein (PTDV) was located in all asterional areas. The PTDV was the dominant diploic vessel in all sides. The FDV and ATDV could be damaged during supraorbital, modified orbitozygomatic, and pterional craniotomies. The anterior DVS connected with the sphenoparietal and superior sagittal sinus (SSS). The posterior DVS connected with the transverse and sigmoid sinuses and was the dominant diploic vessel in all 24 sides. Of all the major diploic vessels, the location and pattern of distribution of the FDV were the most constant. The parietal bone contained the most diploic vessels. No diploic veins were found in the area delimited by the temporal squama. CONCLUSIONS: The pterional, orbitozygomatic, and supraorbital approaches place the FDV and ATDV at risk. The major anterior diploic system connects the SSS with the sphenoparietal sinus. The posterior diploic system connects the SSS with the transverse and sigmoid sinuses.

Arterial Anomalies of the Middle Ear: A Pictorial Review with Clinical-Embryologic and Imaging Correlation.

The differential diagnosis of a red and/or pulsatile retrotympanic mass includes aberrant internal carotid artery, persistent stapedial artery (PSA), glomus tympanicum, and dehiscent jugular bulb. By recognizing the features of aberrant internal carotid artery and PSA on high-resolution computed tomography, these entities can be assessed by the radiologist. PSA is further classified by type because each type demonstrates a unique set of imaging features in addition to features common to all types. Although rarely encountered, it is important to reliably and consistently detect these anomalies because failure to do so can lead to disastrous surgical outcomes.

Applicability of vital staining and tissue clearing to vascular anatomy and melanocytes' evaluation of temporal bone in six laboratory species.

The purpose of the present study was to define the applicability of tissue clearing to the field of otology. We combined tissue clearing with vital staining perfusion via a pumping system to examine the vascular anatomy of temporal bones in laboratory animals. We used six different types of species including Korean wild mouse, mouse, Mongolian gerbil, hamsters and Guinea pigs. A mixture of Alcian blue reagent and 4% paraformaldehyde was circulated throughout the entire circulatory system of the animal via a perfusion pump system. Transparency images were obtained from the temporal bones according to the protocol of the SunHyun 3D Imaging Kit. In examining the inner surface of the tympanic membrane, flaccid part (pars flaccida) was positioned along the entire marginal area in Guinea pig. In the Guinea pig, unlike the other species, the cortical bone of the mastoid (bullae) was easily removed using cold instruments, allowing a direct approach to the enclosed structures. The distribution and pattern of cochlea melanocytes were compared among the species. "Mobius strip"-like accumulated melanocytes in vestibules were shown in both the Korean wild mouse and mouse. The collateral blood supply to the cochlea in six different species was checked in various pattern. Combining dye infusion with tissue-clearing techniques, we documented the middle ear and transparent inner ear structures in six different species. The information and associated images will help other researchers to develop hypotheses and design experimental investigations.

Variations of the vascular canals in the cochlear implant candidates.

OBJECTIVE: To evaluate the incidence of vascular canal variations in the pediatric cochlear implant (CI) candidates. METHODS: We retrospectively reviewed temporal bone computed tomography (CT) images of the CI candidates between November 2013 and November 2018. The presence of high riding jugular bulb, dehiscent jugular bulb, jugular bulb diverticulum, bulging of sigmoid sinus, mastoid emissary vein (MEV), carotid canal dehiscence, and aberrant internal carotid canal were evaluated. Findings were compared with a control group of normal-hearing subjects. RESULTS: Temporal CT images of 118 CI candidates and 119 control group participants were evaluated. The vascular canal anomalies were found in 88 (37.3%) temporal bones of the CI candidates and 49 (20.6%) of the control group (p < 0.001). In 236 temporal CT scans of the CI candidates and 238 temporal CT scans of the control group, we found MEV in 19.1% and 6.3%, high riding jugular bulb in 11.4% and 10.5%, dehiscent jugular bulb in 2.1% and 1.3%, jugular bulb diverticulum in 6.4% and 1.7%, bulging sigmoid sinus in 11.4% and 4.2%, carotid canal dehiscence in 0.8% and 1.3%, and aberrant internal carotid canal in 0 and 0.8%, respectively. Jugular bulb diverticulum (p = 0.01), bulging of the sigmoid sinus (p = 0.003), and MEV (p < 0.001) were more frequent in the CI candidates. CONCLUSION: Vascular canal variations are more common in the CI candidates and should be evaluated before CI surgery.

High age at the time of implant installation is correlated with increased loss of osseointegrated implants in the temporal bone.

BACKGROUND: The implant failure rate in temporal bone has been reported to be about 5 to 10% over a 10-year period. A number of our elderly patients have shown increased failure rates over a long time period, which is the reason for the present study. PURPOSE: The aim of the present study was to find out if age is correlated with implant failure and to measure blood flow in implant sites. MATERIALS AND METHODS: The long-time survival of 131 osseointegrated implants installed in the temporal bones of 81 patients was correlated with the age of the patient at the time of installation. The blood flow in 37 fixture installation sites in 22 patients was recorded by means of laser Doppler flowmetry. RESULTS: The mean implant failure rate in the study group was 9.8% after a mean follow-up time of 7.6 years. There was a significant increase of implant failure in patients above 60 years of age. There was further a trend that implants used for the bone-anchored hearing aid were lost to a higher proportion than implants used for bone-anchored episthesis. There was also a trend that female patients lost fewer implants than males. Blood flow in the temporal bone correlated well with the age of the patient in that the highest values were recorded from the youngest patients. CONCLUSIONS: Increasing age affects failures of osseointegrated implants in the temporal bone. Blood flow is higher in the child's temporal bone, a factor that can be of importance to understand why age influences implant survival.

The significance of assessing the perineural vascular plexus for locating the facial nerve in microsurgery of the ear.

CONCLUSIONS: The perineural vascular plexus is a reliable indicator for the detection of the horizontal segment of the facial nerve in surgery for otologists and neurologists. OBJECTIVE: To evaluate the validity and reliability of the perineural vascular plexus for locating the facial nerve in microsurgery of the ear to avoid iatrogenic facial paralysis. PATIENTS AND METHODS: Our study group comprised 311 patients who underwent tympanoplasty or facial nerve decompression from July 2002 to July 2005. The validity of using the perineural vascular plexus to locate the facial nerve was observed and assessed. RESULTS: The perineural vascular plexus was well differentiated on the horizontal mesotympanic segment of the nerve in 95.8% of patients. The 95% confidence interval was 93.6-98.0%.