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.

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.

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.

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.

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.

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.

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.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery.

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

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.

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.

Cochlear Implantation in a Patient With Pfeiffer Syndrome and Temporal Bone Vascular Anomalies.

OBJECTIVE: Pfeiffer syndrome is a rare craniosynostotic disorder resulting in premature bony fusion of the skull, which can result in abnormal temporal bone and vascular anatomy and hearing loss. Cochlear implantation in these patients requires thoughtful surgical planning given the potential for limited access to the cochlea because of subcutaneous or intratemporal vasculature. Herein, we present a patient with Pfeiffer syndrome who underwent successful cochlear implantation using preoperative Doppler ultrasound to identify large extracranial venous anatomy followed by a modified transcanal surgical approach. PATIENTS: An adult female patient with Pfeiffer syndrome. INTERVENTION(S): Preoperative axial computed tomography, catheter angiography, Doppler ultrasound, and right side cochlear implant. MAIN OUTCOME MEASURE(S): Surgical feasibility and audiometric outcomes including aided thresholds and word recognition score. RESULTS: Successful cochlear implantation was performed via a modified transcanal approach with blind sac closure of the external auditory meatus. Full electrode insertion was obtained through a round window approach. No extracranial or intratemporal vessels were encountered during surgery. CONCLUSION: Patients with significant craniosynostoses and vascular malformations of the temporal bone can undergo successful cochlear implantation. Careful preoperative planning with high-resolution CT, MRA, and MRV, and/or traditional catheter angiography can assist in determining surgical feasibility and minimizing risk. We recommend preoperative Doppler ultrasound of abnormal extracranial vessels to assist in safe placement of incisions and hardware.

Combined flaps based on the superficial temporal vascular system for reconstruction of facial defects.

BACKGROUND: Facial defects are multicomponent deficiencies rather than simple soft-tissue defects. Based on different branches of the superficial temporal vascular system, various tissue components can be obtained to reconstruct facial defects individually. METHODS: From January 2004 to December 2013, 31 patients underwent reconstruction of facial defects with composite flaps based on the superficial temporal vascular system. RESULTS: Twenty cases of nasal defects were repaired with skin and cartilage components, six cases of facial defects were treated with double island flaps of the skin and fascia, three patients underwent eyebrow and lower eyelid reconstruction with hairy and hairless flaps simultaneously, and two patients underwent soft-tissue repair with auricular combined flaps and cranial bone grafts. All flaps survived completely. Donor-site morbidity is minimal, closed primarily. Donor areas healed with acceptable cosmetic results. The final outcome was satisfactory. CONCLUSION: Combined flaps based on the superficial temporal vascular system are a useful and versatile option in facial soft-tissue reconstruction.

Vascularized rotational temporal bone flap for repair of anterior skull base defects: a novel operative technique.

Repair of anterior skull base defects with vascularized grafts poses a significant challenge, given the location and small number of adequately sized vessels for free-flap anastomosis. This is particularly the case in the setting of redo surgery or in patients with preexisting soft-tissue trauma. Even more difficult is achieving a vascularized bone flap closure of such bony defects. The authors report a novel technique involving a rotational temporal bone flap with a temporalis muscle vascularized pedicle, which was used to repair an anterior fossa bony and soft-tissue defect created by recurrent malignancy. A 55-year-old man with history of scalp avulsion during a motor vehicle accident, anterior fossa/nasopharyngeal malignant neuroendocrine carcinoma postresection, and bone flap infection presented with a recurrence of his skull base malignancy. The tumor was located in the anterior fossa, extending interhemispherically and down through the cribriform plate, ethmoid air cells, and extending into the nasopharyngeal cavity. Resection of the recurrent tumor was performed. The bony defect in the anterior skull base was repaired with a novel vascularized rotational temporal bone flap, with acceptable separation of the nasopharynx from the intracranial cavity. The vascularized rotational temporal bone flap, in which a temporalis muscle pedicle is used, provides a novel and easily accessible means of vascularized bone closure of anterior skull base defects without the need for microsurgical free-flap grafting.

Three-dimensional temporal bone reconstruction from histological sections.

OBJECTIVE: To produce a high-resolution, three-dimensional temporal bone model from serial sections, using a personal computer. METHOD: Digital images were acquired from histological sections of the temporal bone. Image registration, segmentation and three-dimensional volumetric reconstruction were performed using a personal computer. The model was assessed for anatomical accuracy and interactivity by otologists. RESULTS: An accurate, high-resolution, three-dimensional model of the temporal bone was produced, containing structures relevant to otological surgery. The facial nerve, labyrinth, internal carotid artery, jugular bulb and all of the ossicles were seen (including the stapes footplate), together with the internal and external auditory meati. Some projections also showed the chorda tympani nerve. CONCLUSION: A high-resolution, three-dimensional computer model of the complete temporal bone was produced using a personal computer. Because of the increasing difficulty in procuring cadaveric bones, this model could be a useful adjunct for training.

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.

Vascularization of the facial bones by the facial artery: implications for full face allotransplantation.

BACKGROUND: The maxillary artery is recognized as the main vascular supply of the facial bones; nonetheless, clinical evidence supports a codominant role for the facial artery. This study explores the extent of the facial skeleton within a facial allograft that can be harvested based on the facial artery. METHODS: Twenty-three cadaver heads were used in this study. In 12 heads, the facial, superficial temporal, and maxillary arteries were injected. In one head, facial artery angiography was performed. Ten facial allografts were raised. The soft tissues were dissected to show the arterial anastomotic connections. Radiographs and computed tomographic scans were obtained. RESULTS: Constant anastomosis between the facial, inferior alveolar, and infraorbital arteries at the mental and infraorbital foramina were found. The facial artery vascularized the homolateral mandibular symphysis, body, and ramus. The condylar and coronoid processes were vascularized in 67 percent of the allografts. The homolateral maxilla was contrasted in all allografts. The alveolar and palatine processes contained the contrast in 83 percent of specimens. The maxillary process of the zygomatic bone was perfused in all allografts, followed by the body, frontal (83 percent), and temporal processes (67 percent). The nasal lateral wall and septum were vascularized in 83 percent of the allografts. The medial and lateral orbital walls and the orbital floor were stained in all specimens. The zygomatic process of the temporal bone was the least perfused bone. CONCLUSION: A composite allograft containing 90 to 95 percent of the facial bones can be based on bilateral facial arteries.

Petrosquamosal sinus: clinical characteristics based on radiologic and operative findings.

OBJECTIVE: Petrosquamosal sinus (PSS) is an embryonic emissary vein of the temporal bone connecting the intracranial and extracranial venous networks, which is present in some variants of venous cerebral drainage. The aim of the present study was to analyze 20 cases of PSS and to present its clinical characteristics and implications. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: By reviewing retrospective medical records and TBCT findings, a total of 20 PSS cases were found. Based on the shapes of PSS demonstrated on TBCT, PSS was classified into tortuous and straight types. The course and thickness of PSS were also investigated. The average thicknesses of PSS between tortuous and straight types were compared. RESULTS: The mean age of the patients was 54.1 ± 16.2 years. The study group consisted of 7 male (35.0%) and 13 female (65.0%) patients. Eleven cases were found on the right side and 8 cases on the left side. The mean diameter of the bony canal that PSS courses on TBCT was 2.57 ± 0.88 mm. Its maximal and minimal diameters were 4.2 and 0.7 mm. The average diameter of tortuous type PSSs (3.04 ± 0.75 mm) was significantly larger compared with that of straight-type PSSs (2.09 ± 0.76 mm) (p < 0.05). CONCLUSION: Preoperative identification of PSS using TBCT may be important for safe mastoid surgery. The presence of PSS should be identified with thorough examination of radiographic findings before mastoid surgery.