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Ultrasonographic assessment of the maxillary artery and middle meningeal artery in the infratemporal fossa
Abstract
Purpose
To investigate with Doppler ultrasonography the maxillary and middle meningeal arteries in the infratemporal fossa, and describe their hemodynamic characteristics.
Methods
We included 24 female and 11 male volunteers without vascular diseases, with a median age of 43 years. We used the acoustic window, enlarged by subjects half‐opening their mouth, located below the zygomatic arch, in front of temporo‐mandibular joint, to reach the maxillary and middle meningeal arteries.
Results
In the 35 subjects, 112 arteries were visualized successfully: 60 maxillary (85.7%), and 52 middle meningeal arteries (74.3%), at a depth of 2.40 and 2.50 cm, respectively. Their blood flow was directed anteriorly and away from the probe. While all the measured hemodynamic characteristics differed significantly between the maxillary and the middle meningeal artery (P < 0.001), there was no significant difference between male and female subjects, nor between the left or the right side.
Conclusions
The maxillary and middle meningeal arteries can be insonated in the infratemporal fossa through the easily accessible acoustic window below the zygomatic arch, when the patient holds his mouth half open. They can be differentiated by their ultrasonographic characteristics and blood flow features.
... The most common complication is intraoperative haemorrhage due to injury to the adjacent vasculature. [20] Haemorrhagic complications of TMJ surgeries may be intracranial/extracranial. [20][21][22][23][26][27][28] Extracranial complications are likely to involve superficial temporal vessels, maxillary artery, middle meningeal artery and ICA. ...
... Intracranial complications involve extradural haemorrhage due to rupture of the middle meningeal artery and are life-threatening. [20][21][22][23][26][27][28] MRI provides images about muscles, vessels, nerves within the TMJ and masticator spaces which may be a useful guide to plan surgical approaches to the TMJ region due to the closeness of myriad vital structures within this limited space often complicating operative procedures. [17,24,29] In our study osseous structures display clear hypointense signals on MRI and are differentiated from the adjacent soft tissue, allowing preoperative measurements to be made between bony anatomical landmarks. ...
... A flow void indicates a signal loss caused by rapid blood flow and hence act as natural contrasts and are a clinical focus of attention in the diagnosis of vascular abnormalities [ Figures 1 and 2]. [21] On a noncontrast CT scan, the vessels may appear as a radiolucency traversing the radiopaque ankylotic mass suggesting the presence of the vessel within the mass. On a CT angiogram with contrast, it appears as a hypointense structure adjacent to the osseous structures. ...
Introduction:
Temporomandibular joint (TMJ) ankylosis is a pathologic condition where the mandible is fused to the fossa by bony or fibrotic tissues. Haemorrhage is one of the major complications during TMJ surgery especially in ankyloses due to altered anatomy. The aim of the study was to analyse the proximity of the vasculature to the TMJ region in TMJ ankylosis patients using magnetic resonance imaging (MRI).
Materials and methods:
Noncontrast-enhanced MRI images of seven patients were assessed. The distance between maxillary artery and neck of condyle/ankylotic mass was measured using coronal sections and distance between the internal carotid artery (ICA), internal jugular vein (IJV) and medial edge of condyle/bony mass were measured using axial sections.
Results:
The mean distance of internal maxillary artery (IMA) to medial edge of ankylotic mass was 1 ± 0.57 mm and 2 ± 1.2 mm-left and right condylar regions respectively (range: 0-4 mm).The mean distance from lateral aspect of ankylotic mass to IMA was 8.2 ± 1.4 mm and 8.7 ± 2.8 mm-right and left condylar regions respectively (range: 3-11 mm).The mean distance from medial edge of condyle to ICA was 18.8 ± 1.3 mm and 18.2 ± 1.1 mm-right and left condylar regions respectively (range: 17 mm-20 mm).The mean distance from the medial edge of condyle to IJV was 16.4 ± 1.1 mm and 14.5 ± 2.9 mm-right and left condylar regions (range: 11 mm-19 mm).
Discussion:
These measurements were used as a guide to plan the steps during surgery in order to minimise the intraoperative haemorrhagic complications. Hence, MRI may be considered as a valuable tool in assessing the juxtaposition of vascular bed to TMJ region, though contrast MRI and a larger sample is needed to standardise.
... It should be noted that such imaging needs to be done only once (preferably before the first injection), and giving contrast is not always necessary to detect the MA neighboring the LPM [18]. Doppler ultrasonography (USG) is another alternative [18,19]. The MA can be visualized in the infratemporal fossa through the acoustic window between the zygomatic arch and the mandibular notch by asking the patient to open her/his mouth half-open. ...
... The MA can be visualized in the infratemporal fossa through the acoustic window between the zygomatic arch and the mandibular notch by asking the patient to open her/his mouth half-open. It has been reported that the MA cannot be visualized in the case of a medial course [18,19], indicating that a Doppler signal of the MA in USG would confirm a lateral course. In addition to those, recently, intraoral appliances customized for the patient with needle guides produced using computeraided technologies were suggested to increase the precision of injections [13,20]. ...
It has been suggested that the variations in the trajectory of the maxillary artery (MA) near the lateral pterygoid muscle (LPM) play a critical role in Botulinum neurotoxin (BoNT) injections in patients with jaw-opening/deviation dystonia (JOD). In the case of a lateral course to the LPM, an extraoral injection entails risks of MA injury, pain, and hematoma. Previous reports suggest geographical differences in variations of the MA-LPM relationship. We aimed to determine these variations in Turkish individuals and highlight the need to establish a consensus on approach to LPM injections. In 284 individuals, contrast-enhanced magnetic resonance angiography (MRA) images were evaluated by two radiologists on both sides for the variations in the course of the MA in the infratemporal fossa. Images of 44 were excluded due to trauma, arteriovenous malformation, mass, surgery, and imaging artifacts. Of the included, 62.1% were female. In 480 evaluations of 240 individuals, the MA passed lateral to the LPM in 65.6% (n = 315). No sex difference was noted. In 51 individuals (21.3%), the MA course differed on the right and left sides (medial–lateral asymmetry). These results confirm that the lateral course of the MA is more frequent. In patients with JOD, the trajectory of the MA should be determined with imaging prior to extraoral BoNT injections. In the case of a lateral course, an intraoral approach seems to be safer to avoid a potential MA injury.
... The technique to view the maxillary artery has been described in detail. 6 The artery is viewed in the infratemporal fossa between the condylar and coronoid processes of the mandible. The temporomandibular joint must be semi-depressed to allow an optimum window. ...
... Lepic et al. visualised it in 85% of their patients. 6 The involvement of the maxillary artery in GCA is supported on clinical and anatomical grounds. Chewing diffi culties and jaw claudication are present in up to 45% of individuals with GCA. 9 The muscles of mastication are supplied directly by the maxillary artery. ...
We describe two cases of giant cell arteritis where involvement of the superficial temporal artery and maxillary artery were demonstrated using colour doppler ultrasonography. Maxillary artery involvement is responsible for the symptoms of jaw claudication and toothache, and even headaches might be due to the involvement of the middle meningeal artery which is a branch of the maxillary artery. The maxillary artery has been difficult to visualise until now. There are international consensus definitions of ultrasonographic abnormalities seen in the superficial temporal artery affected by giant cell arteritis. We have used those definitions to demonstrate hypoechoic changes in the maxillary artery affected by giant cell arteritis. The maxillary artery can be visualised in the infratemporal fossa from an echo window between the condylar and coronoid processes of the mandible. This is the first proof of concept evidence that maxillary arteries can be visualised using bedside ultrasonography in giant cell arteritis.
... The limited visibility and accessibility associated with minimally invasive and endoscopic procedures in narrow anatomical regions are associated with a risk of iatrogenic vascular injury, which leads to bleeding that is difficult to control and potentially life-threatening. Several imaging studies have described the close relationships between the maxillary and middle meningeal arteries and osseous structures [7][8][9][10][11][12]. However, the minimal distances between these structures remain difficult to predict for an individual patient; at present, it is not possible to generally delimit a safe surgical region. ...
Purpose
The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been revealed by both imaging and cadaveric studies. This study aimed to verify the previously published information in a large sample and to determine a safe surgical region.
Methods
We analyzed the three-dimensional time-of-flight magnetic resonance angiography images of 300 individuals.
Results
The mean distance between the middle meningeal artery and the apex of the condyle or the most medial point of the condyle was 18.8 mm (range: 11.2–25.9 mm) or 14.5 mm (range: 8.8–22.9 mm) respectively. The course of the maxillary artery relative to the lateral pterygoid muscle was medial in 45.7% of cases and lateral in 54.3%. An asymmetric course was evident in 66 patients (22%). The mean distance between the maxillary artery and condylar process at the deepest point of the mandibular notch was 6.2 mm in sides exhibiting a medial course (range: 3.7–9.8 mm) and 6.6 mm in sides exhibiting a lateral course (range: 3.9–10.4 mm). The distances were significantly influenced by age, gender, and the course of the maxillary artery.
Conclusion
Our study emphasizes the marked inter- and intra-individual variability of the maxillary and middle meningeal arterial courses. We confirmed the proximity of the arteries to the condylar process. Extensive surgical experience and thorough preparation for each individual case are essential to prevent iatrogenic vascular injury.
... However, meningeal vascular tone can vary independently of systemic arterial pressure. The middle meningeal artery has its own intrinsic independent autoregulation and only minimally (or differentially) responded to drugs able to induce larger changes in the other vascular beds (75)(76)(77)(78). Likewise, a study from Ashina and colleagues showed that while there were no differences in extracranial blood vessels during spontaneous migraines in humans, intracranial arteries had a slight dilation during the attacks (13). ...
Background
Calcitonin gene-related peptide is recognized as a key player in migraine, yet the mechanisms and sites of calcitonin gene-related peptide action remain unknown. The efficacy of calcitonin gene-related peptide-blocking antibodies as preventative migraine drugs supports a peripheral site of action, such as the trigeminovasculature. Given the apparent disconnect between the importance of vasodilatory peptides in migraine and the prevailing opinion that vasodilation is an epiphenomenon, the goal of this study was to test whether vasodilation plays a role in calcitonin gene-related peptide-induced light aversive behavior in mice.
Methods
Systemic mean arterial pressure and light aversive behavior were measured after intraperitoneal administration of calcitonin gene-related peptide and vasoactive intestinal peptide in wild-type CD1 mice. The functional significance of vasodilation was tested by co-administration of a vasoconstrictor (phenylephrine, endothelin-1, or caffeine) with calcitonin gene-related peptide to normalize blood pressure during the light aversion assay.
Results
Both calcitonin gene-related peptide and vasoactive intestinal peptide induced light aversion that was associated with their effect on mean arterial pressure. Notably, vasoactive intestinal peptide caused relatively transient vasodilation and light aversion. Calcitonin gene-related peptide-induced light aversion was still observed even with normalized blood pressure. However, two of the agents, endothelin-1 and caffeine, did reduce the magnitude of light aversion.
Conclusion
We propose that perivascular calcitonin gene-related peptide causes light-aversive behavior in mice by both vasomotor and non-vasomotor mechanisms.
The upper head of the lateral pterygoid muscle (LPM) is known to insert into the capsule of the temporomandibular joint and articular disc, and therefore its relationship with temporomandibular disorders (TMD) has been consistently suggested. The aim of the study was to determine the anatomical features of the LPM using ultrasonographic (US) imaging. Around 120 hemifaces from 60 healthy Korean volunteers were included in this study. US images were taken with the subject's mouth 2 cm open. The transducer was placed at a position where the infratemporal fossa could be observed through the mandibular notch, and its position was recorded. The locations of the coronoid process (CorP), lateral margin of the condylar process (ConP), and midpoint of CorP and ConP (MP) were measured with reference to the ala‐tragus line. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM were measured at the MP. The masseter muscle, temporalis muscle, and LPM were observed in all cases and located in order from superficial to deep. The MP was located 39.6 ± 3.3 mm anterior and 7.8 ± 1.6 mm inferior to the tragus. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM at the MP were 9.7 ± 1.0, 10.3 ± 1.3, 10.9 ± 1.6, and 30.9 ± 1.9 mm, respectively. The information reported in this study may be useful for determining the location of the LPM and adjacent anatomical structures in TMD patients and provide accurate and safe injection guidelines.
Background
Burr hole surgery for moyamoya disease and moyamoya syndrome is known to be an effective, versatile, and relatively simple revascularization technique. We will focus on the technical operative aspects of multiple burr hole surgery as we perform it in our center.
Methods
Periosteal flaps are prepared and placed in a burr hole with beveled edge, after opening the dura and arachnoid membrane, in order to facilitate neovascularization into the ischemic cortex.
Conclusions
Burr hole surgery is a versatile treatment modality for moyamoya and moyamoya-like disease. Success can be maximized by having a meticulous operative technique.
Background:
To analyze the face vascularization pattern using B-mode and Doppler ultrasonography, and also propose an arterial vessel mapping.
Material and methods:
The investigation was performed on 20 ultrasonography exams of facial vessels through linear and endocavitary transducers. We analyzed and determined the average values for diameters, peak systolic velocity and resistive index of the following arteries: external carotid, lingual, deep lingual, sublingual, facial, submental, inferior labial, superior labial, angular, maxillary inferior alveolar, mental, buccal, greater palatine, infraorbital, superficial temporal, transverse facial and frontal.
Results:
Data was obtained allowing the analysis of the tissue hemodynamics. We were able to map the vascularization of the face and it was possible to access three arteries of small diameter (0,60mm angular artery; 0,55mm greater palatine artery; 0,45mm infraorbital artery).
Conclusions:
The results presented in this article are valid tool supporting the non-invasive mapping of facial vascularization.
Background: To analyze the face vascularization pattern using B-mode and Doppler ultrasonography, and also propose an arterial vessel mapping.
Material and Methods: The investigation was performed on 20 ultrasonography exams of facial vessels through linear and endocavitary transducers. We analyzed and determined the average values for diameters, peak systolic velocity and resistive index of the following arteries: external carotid, lingual, deep lingual, sublingual, facial, submental, inferior labial, superior labial, angular, maxillary inferior alveolar, mental, buccal, greater palatine, infraorbital, superficial temporal, transverse facial and frontal.
Results: Data was obtained allowing the analysis of the tissue hemodynamics. We were able to map the vasculari- zation of the face and it was possible to access three arteries of small diameter (0,60mm angular artery; 0,55mm greater palatine artery; 0,45mm infraorbital artery).
Conclusions: The results presented in this article are valid tool supporting the non-invasive mapping of facial vascularization.
The middle meningeal artery is traditionally described by the human anatomy books as having its origin in the first portion of the maxillary artery. However, more detailed studies have shown that there are numerous variations on this arterial segment with considerable clinical importance. Therefore, the aim of this study was to perform a wide review about this aspect analyzing scientific articles and textbooks. Thus, this review shall be useful for clinicians, surgeons and academics that manipulate and keep interest for this particular anatomical site.
Given recent technological developments, ultrasound Doppler can provide valuable measurements of blood velocity/flow in the conduit artery with high temporal resolution. In human-applied science such as exercise physiology, hemodynamic measurements in the conduit artery is commonly performed by blood flow feeding the exercising muscle, as the increase in oxygen uptake (calculated as a product of arterial blood flow to the exercising limb and the arterio-venous oxygen difference) is directly proportional to the work performed. The increased oxygen demand with physical activity is met through a central mechanism, an increase in cardiac output and blood pressure, as well as a peripheral mechanism, an increase in vascular conductance and oxygen extraction (a major part of the whole exercising muscles) from the blood. The increase in exercising muscle blood flow in relation to the target workload (quantitative response) may be one indicator in circulatory adjustment for the activity of muscle metabolism. Therefore, the determination of local blood flow dynamics (potential oxygen supply) feeding repeated (rhythmic) muscle contractions can contribute to the understanding of the factors limiting work capacity including, for instance, muscle metabolism, substance utilization and magnitude of vasodilatation in the exercising muscle. Using non-invasive measures of pulsed Doppler ultrasound, the validity of blood velocity/flow in the forearm or lower limb conduit artery feeding to the muscle has been previously demonstrated during rhythmic muscle exercise. For the evaluation of exercising blood flow, not only muscle contraction induced internal physiological variability, or fluctuations in the magnitude of blood velocity due to spontaneous muscle contraction and relaxation induced changes in force curve intensity, superimposed in cardiac beat-by-beat, but also the alterations in the blood velocity (external variability) due to a temporary sudden change in the achieved workload, compared to the target workload, should be considered. Furthermore, a small amount of inconsistency in the voluntary muscle contraction force at each kick seems to be unavoidable, and may influence exercising muscle blood flow, although subjects attempt to perform precisely similar repeated voluntary muscle contractions at target workload (muscle contraction force). This review presents the methodological considerations for the variability of exercising blood velocity/flow in the limb conduit artery during dynamic leg exercise assessed by pulsed Doppler ultrasound in relation to data previously reported in original research.
The aim of this study was to investigate the anatomy of the maxillary artery (MA) and its branches. Fourteen sides of Turkish adult cadavers were dissected. The specimens were classified according to the relation between MA and the lateral pterygoid. After the removal of the lateral pterygoid, parts and branches of MA were exposed. We classified the branching patterns of MA in the pterygopalatine fossa. The calibers and lengths of the arteries, and the distance between the zygomatic arch and MA, and between the infratemporal crest and MA were measured. The MA was found superficial to the lateral pterygoid in 57.2%. The inferior alveolar artery (IA) was arisen from MA before the middle meningeal artery (MM) in 35.7%, after MM in 35.7%. The IA and MM were arisen from the same area of MA in 14.3 %. In other two cases IA was arisen from the beginning of MA (14.3%). According to the contours of third portion of MA, we classified "Y" type (50%), "intermediate-T" type (14.3%), and "M" type (35.7%). This reinvestigation of the clinical anatomy of MA may provide useful information to the head and neck surgeons, dentists, neurosurgeons and radiologists related with this region.
Migraine attacks occur spontaneously in those who suffer from the condition, but migraine-like attacks can also be induced artificially by a number of substances. Previously published evidence makes the meninges a likely source of migraine related pain. This article investigates the effect of several vasodilators on meningeal arteries in order to find a connection between the effect of a substance on a meningeal vessel and its ability to artificially induce migraine.
A myograph setup was used to test the vasodilator properties of the substances acetylcholine (ACh), sodium nitroprusside (SNP), sildenafil, prostaglandin E2 (PGE2), pituitary adenylate cyclase activating peptide-38 (PACAP-38), calcitonin gene-related peptide (CGRP) and NaCl buffer on meningeal arteries from human and rat. An unpaired t-test was used to statistically compare the mean Emax(%) at the highest concentration of each substance to the Emax(%) of NaCl buffer.
In the human experiments, all substances except PACAP-38 had an Emax(%) higher than the NaCl buffer, but the difference was only significant for SNP and CGRP. For the human samples, clinically tested antimigraine compounds (sumatriptan, telcagepant) were applied to the isolated arteries, and both induced a significant decrease of the effect of exogenously administrated CGRP. In experiments on rat middle meningeal arteries, pre-contracted with PGF2alpha, similar tendencies were seen. When the pre-contraction was switched to K+ in a separate series of experiments, CGRP and sildenafil significantly relaxed the arteries.
Still no definite answer can be given as to why pain is experienced during an attack of migraine. No clear correlation was found between the efficacy of a substance as a meningeal artery vasodilator in human and the ability to artificially induce migraine or the mechanism of action. Vasodilatation could be an essential trigger, but only in conjunction with other unknown factors. The vasculature of the meninges likely contributes to the propagation of the migrainal cascade of symptoms, but more research is needed before any conclusions can be drawn about the nature of this contribution.
Aim:
To explore a possible differential effect of sumatriptan on extracerebral versus cerebral arteries, we examined the superficial temporal (STA), middle meningeal (MMA), extracranial internal carotid (ICAextra), intracranial internal carotid (ICAintra), middle cerebral (MCA) and basilar arteries (BA).
Methods:
The arterial circumferences were recorded blindly using high-resolution magnetic resonance angiography before and after subcutaneous sumatriptan injection (6 mg) in 18 healthy volunteers.
Results:
We found significant constrictions of MMA (16.5%), STA (16.4%) and ICAextra (15.2%) ( P ≤ 0.001). Smaller, but statistically significant, constrictions were seen in MCA (5.5%) and BA (2.1%) ( P ≤ 0.012). ICAintra change 1.8% was not significant ( P = 0.179). The constriction of cerebral arteries was significantly smaller than the constriction of extracerebral arteries ( P < 0.000001).
Conclusion:
Sumatriptan constricts extracerebral arteries more than cerebral arteries. We suggest that sumatriptan may exert its anti-migraine action outside of the blood-brain barrier.
Many authors have studied variation in the maxillary artery but there have been inconsistencies between reported observations. The present research aimed to examine the courses and branching patterns of the trunk and branches of the maxillary artery in a large sample of Japanese adult cadavers. The course of the maxillary artery should be reclassified into seven groups as a clear relationship was found between the origin of the middle meningeal artery and the course of the maxillary artery. This indicates that conventional theory about the formation of the maxillary artery, which was considered to be a direct derivative of the stapedial artery, might be inaccurate. Many variations in the origin of the inferior alveolar artery were found. Notably, the inferior alveolar artery origin from the external carotid artery and a double origin of the inferior alveolar artery was also observed. Thus, the maxillary artery might be derived from a combination of both the external carotid and stapedial arteries.
To explore a possible relationship between vasodilatation and delayed headache we examined the effect of pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) on the middle meningeal artery (MMA) and middle cerebral artery (MCA) using high resolution magnetic resonance angiography (MRA).
In a double-blind, randomized, placebo-controlled study 14 healthy volunteers were scanned repeatedly after infusion (20 min) of 10 pmol/kg/min PACAP38 or placebo. In addition, four participants were scanned following subcutaneous sumatriptan (6 mg).
We found significant dilatation of the MMA (p = 0.00001), but not of the MCA (p = 0.50) after PACAP38. There was no change after placebo (p > 0.40). Vasodilatation (range 16-23%) lasted more than 5 h. Sumatriptan selectively contracted the MMA by 12.3% (p = 0.043).
PACAP38-induced headache is associated with prolonged dilatation of the MMA but not of the MCA. Sumatriptan relieves headache in parallel with contraction of the MMA but not of the MCA.
The possibility of creating a middle meningeal artery (MMA)-to-petrous internal carotid artery (ICA) bypass was investigated in six cadavers (bilaterally). Such a procedure could be used to treat patients with high cervical vascular lesions and those with tumors of the infratemporal fossa invading the high cervical ICA. After a frontotemporal craniotomy, the foramen spinosum and foramen ovale were exposed extradurally. Immediately posterior to the foramen ovale and medial to the foramen spinosum, the petrous portion of the ICA was exposed with a diamond-tipped drill. The MMA was lifted from its groove, and a sufficient length was transected to perform a bypass with the petrous ICA medially. The mean width of the MMA at the site of anastomosis was 2.3 +/- 0.35 mm. The mean length of MMA from the foramen spinosum to the site of the anastomosis was 9.6 +/- 1.7 mm. Based on these measurements, width and length of MMA appear to be sufficient for a bypass with petrous ICA.
Internal maxillary artery (IMA) bypass has gain momentum in the last 5 years for the treatment of complex cerebrovascular disorders and skull base tumors. However, some issues regarding this treatment modality have been proposed. As one of the most experienced neurosurgical team to perform internal maxillary artery bypass in the world (＞100 clinical cases), we reviewed literature in aspects of basic anatomy of maxillary artery with its variations to the lateral pterygoid muscle, initial anastomosis modalities and subsequent exposure techniques in cadaver studies, pre-operative arterial evaluation methods, optimal interposed graft selections and surgical outcome in the management of complex aneurysms, skull base tumors and steno-occlusive disorders.
BACKGROUND: Traditional treatment for symptomatic subdural hematoma (SDH) has been surgical evacuation, but recurrence rates are high and patients often harbor complex medical comorbidities. Growth and recurrence is thought to be due to the highly friable nature of the vascularized membrane that forms after initial injury. There have been reported cases of middle meningeal artery (MMA) embolization for treatment of recurrent SDH after surgical evacuation with the goal of eliminating the arterial supply to this vascularized membrane.
OBJECTIVE: To present the first known case series of MMA embolization as upfront treatment for symptomatic chronic SDHs that have failed conservative management in lieu of surgical evacuation.
METHODS: Five patients with symptomatic chronic SDHs underwent MMA embolization using PVA microparticles at our institution. Size of SDH was recorded in maximum diameter and total volume.
RESULTS: Four patients underwent unilateral and 1 underwent bilateral MMA embolization successfully. All cases had significant reduction in total volume of SDH at longest follow-up scan: 81.4 to 13.8 cc (7 wk), 48.5 to 8.7 cc (3 wk), 31.7 and 88 to 0 and 17 cc (14 wk, bilateral), 79.3 to 24.2 cc (8 wk), and 53.5 to 0 cc (6 wk). All patients had symptomatic relief with no complications. Histologic analysis of the chronic SDH membrane in a separate patient that required surgery revealed rich neovascularization with many capillaries and few small arterioles.
CONCLUSION: MMA embolization could present a minimally invasive and low-risk initial treatment alternative to surgery for symptomatic chronic SDH when clinically appropriate.
Materials and methods:
Fifty adult dry skulls were investigated. The length of the bony canal and the distance from the orbital rim to the bony canal were measured. Additionally, 28 cadaveric heads were examined histologically.
Results:
Sixty-three bony canals were found in 43 skulls. The mean length of bony canals was 9.2 mm, and the mean distance from the orbital rim was 24.0 mm. The bony canal ran mainly from the sphenoid bone (69.8%) to the parietal bone (73.0%). Histologically, both sides of the meningeal grooves gradually closed the distance, and formed the bony canal. The MMA inside the bony canal was enveloped with collagen tissues, divided into branches, and was accompanied by the vein.
Conclusions:
The bony canal is located around the pterion and is formed during bone growth. The MMA is covered with collagen tissues inside the bony canal. It is possible to safely expose and preserve the MMA during craniotomy with careful drilling.
The aim of this study was to investigate the anatomy of the maxillary artery (MA) and its branches. Fourteen sides of Turkish adult cadavers were dissected. The specimens were classified according to the relation between MA and the lateral pterygoid. After the removal of the lateral pterygoid, parts and branches of MA were exposed. We classified the branching patterns of MA in the pterygopalatine fossa. The calibers and lengths of the arteries, and the distance between the zygomatic arch and MA, and between the infratemporal crest and MA were measured. The MA was found superficial to the lateral pterygoid in 57.2%. The inferior alveolar artery (IA) was arisen from MA before the middle meningeal artery (MM) in 35.7%, after MM in 35.7%. The IA and MM were arisen from the same area of MA in 14.3 %. In other two cases IA was arisen from the beginning of MA (14.3%). According to the contours of third portion of MA, we classified "Y" type (50%), "intermediate-T" type (14.3%), and "M" type (35.7%). This reinvestigation of the clinical anatomy of MA may provide useful information to the head and neck surgeons, dentists, neurosurgeons and radiologists related with this region.
The purpose of this study was to examine the efficacy of ultrasonography (US) and unenhanced magnetic resonance imaging (MRI) to determine the location of the internal maxillary artery (IMA) before orthognathic surgery. The study subjects were 19 patients (seven males and twelve females) with mandibular prognathism seen at the authors' institution between March 2012 and April 2013. The distance from the skin to the IMA (S-IMA) and the distance from the mandibular notch to the IMA (MN-IMA) were measured. Using the US and coronal MRI images, S-IMA(cl) and MN-IMA(cl) in the closed position and S-IMA(op) and MN-IMA(op) in the open position were measured at a total of four points in each cross-section. There were significant correlations between the distances measured on coronal MRI and US for all groups (P<0.05). A total of 35 (92%) IMAs were classified as clear and three (8%) as unclear based on the US findings. Regarding the location of the IMA, 37 of the 38 sides studied (97%) were of the lateral type, while only one (3%) was of the medial type. The results of this study indicate that US can be used effectively to determine the location of the IMA.
Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Publisher Summary
This chapter summarizes the state-of-the-art of intra- and extracranial ultrasound and provides a brief outlook on upcoming new ultrasound applications. Computed tomography technique allowed the study of intracranial hemodynamics non-invasively using ultrasound. Transcranial color-coded duplex sonography(TCCS) was introduced. It is a technique that combines conventional and color-coded Doppler sonography with grayscale imaging. TCCS is focused as a state-of-the-art method for the assessment of intracranial hemodynamics. Due to its non-invasive character and its bedside applicability, transcranial ultrasound is suitable in a setting of thrombolytic therapy. Knowledge of the intracranial vascular status facilitates the indication for thrombolysis or other invasive therapeutic procedures in hyperacute stroke. Transcranial ultrasound can be used to assess the effects of acute stroke treatment (revascularization, hemorrhagic complications) and to monitor the patient's further course. About 50% of all symptomatic stenoses or occlusions of the anterior circulation are located in the proximal portion of the internal carotid artery (ICA). They typically result from atherosclerotic narrowing of the vessel lumen. Large clinical trials have shown the efficacy of surgical over medical treatment of carotid artery stenosis. The risk of stroke and also the indication for carotid endarterectomy depend strongly on the degree of the stenosis. Thus screening for and reliable and valid quantification of the carotid stenosis is of utmost clinical importance and can be achieved by ultrasound investigation. The chapter discusses the doppler spectra analysis, occlusion of the internal carotid artery, occlusion of intracranial arteries, and reliability of transcranial ultrasound.
Ultrasound enables us to monitor the cardiovascular system and brain responses to treatment in real time; a genuine blessing on the route to more effective stroke therapies, and an invaluable tool with which to tailor treatment when available evidence is meagre. Ultrasound is a vital observational tool, yet a probe needs a scientist to point it in the right direction and a skilled physician to synthesise scientific data with practical management strategies. This book, intended for clinicians who are eager to learn and prepared to observe, focusses on the examination of stroke patients, the interpretation of ultrasound studies, and the application of cerebrovascular ultrasound to management and treatment strategies. Produced by an international team of contributors and edited at the University of Texas, one of the major world centres in stroke research, it is a practical volume that can be used by beginners to learn the principles of ultrasound testing, by advanced users to learn differential diagnosis, and by clinicians (non-sonographers) who treat stroke patients. The latter will gain knowledge on how to apply ultrasound, and what to expect from it in terms of clinical decision making and treatment selection. © 2004 by Futura, an imprint of Blackwell Publishing. All rights reserved.
The objective of this study is to clearly and precisely describe the topography and contents of the infratemporal fossa. Ten formalin-fixed, adult cadaveric specimens were studied. Twenty infratemporal fossa were dissected and examined using micro-operative techniques with magnifications of 3-40×. Information was obtained about the inter-relationships of the contents of the infratemporal fossa. The infratemporal fossa lies at the boundary of the head and neck, and the intracranial cavity. It is surrounded by the maxillary sinus anteriorly, the mandible laterally, the pterygoid process anteromedially, and the parapharyngeal space posteromedially. It contains the maxillary artery and its branches, the pterygoid muscles, the mandibular nerve, and the pterygoid venous plexus. The course and the anatomic variation of the maxillary artery and the branches of the mandibular nerve were demonstrated. The three-dimensional (3D) relationships between the important bony landmarks and the neurovascular bundles of the infratemporal fossa were also shown. The skull base anatomy of the infratemporal fossa is complex, requiring neurosurgeons and head and neck surgeons to have a precise knowledge of 3D details of the topography and contents of the region. A detailed 3D anatomic knowledge is mandatory to manage benign or malignant lesions involving the infratemporal fossa without significant postoperative complications. Clin. Anat., 2013. © 2013 Wiley Periodicals, Inc.
Background:
Transcranial Doppler (TCD) ultrasonography has been extensively used in the evaluation and management of patients with cerebrovascular disease since the clinical application was first described in 1982 by Aaslid and colleagues TCD is a painless, safe, and noninvasive diagnostic technique that measures blood flow velocity in various cerebral arteries. Numerous commercially available TCD devices are currently approved for use worldwide, and TCD is recognized to have an established clinical value for a variety of clinical indications and settings. Although many studies have reported normal values, there have been few recently, and none to include a large cohort of healthy subjects across age, race, and gender. As more objective, automated processes are being developed to assist with the performance and interpretation of TCD studies, and with the potential to easily compare results against a reference population, it is important to define stable normal values and variances across age, race, and gender, with clear understanding of variability of the measurements, as well as the yield from various anatomic segments.
Methods:
To define normal TCD values in a healthy population, we enrolled 364 healthy subjects, ages 18-80 years, to have a complete, nonimaging TCD examination. Subjects with known or suspected cerebrovascular disorders, systemic disorders with cerebrovascular effects, as well as those with known hypertension, diabetes, stroke, coronary artery disease, or myocardial infarction, were excluded. Self-reported ethnicity, handedness, BP, and BMI were recorded. A complete TCD examination was performed by a single experienced sonographer, using a single gate nonimaging TCD device, and a standardized protocol to interrogate up to 23 arterial segments. Individual Doppler spectra were saved for each segment, with velocity and pulsatility index (PI) values calculated using the instrument's automated waveform tracking function. Descriptive analysis was done to determine the mean velocities and PI, and all data were analyzed for changes by decade of age, sex race, handedness, BMI, and BP.
Results:
Among the key intracranial segments, mean blood flow velocities (MBFV) were highest in the MCA and lowest in the PCA across all ages, sexes, and ethnic groups. There was no difference in the MBFVs between left and right side segments of the Circle of Willis, with the exception of the distal M1 (P = .022) and the C1 (P < .0001), both slightly higher on the left. MBFV were higher among women than men in all segments except for the OA. MBFV decreased with advancing age in both men and women, but this was specific to Caucasian subjects. There were lower velocities in the OA for non-Caucasians. The PI was lower in the left VA (P < .0001), and for most segments was lower in women than men. The PI increased with age in all segments for women, but only in some segments for men, and this finding was also specific to Caucasian subjects. The yield of usable data ranged from 99.7% for the VA and BA, to 88.2% for C2.
Conclusion:
Our study provides normal, reference TCD values for a large cohort of healthy subjects across a wide range of age, sex, and race groups. We observed decreased MBFV and increased PI with aging, and higher MBFV in women. There were few differences in MBFV related to side or ethnicity, but the MFBV and PI changes with age were specific to Caucasians. We provide means and standard deviations of MBFVs across various demographic groups in key intracranial arteries. Such normal TCD values across age, gender, and ethnic groups in healthy subjects represent a useful reference tool for detecting individuals with TCD values outside normal limits and at increased vascular risk. TCD studies in large multiethnic populations are still required to determine differences in brain hemodynamics across various ethnic groups.
IntroductionTCD examination techniqueWhere to start?M-mode or PMD/TCD examination techniqueTranscranial color duplex imagingTCDI examination techniqueReferences
To show that migraine pain is not related to dilatation of the dural meningeal arteries.
The origin of the pain in migraine has not yet been adequately explained and remains the subject of vigorous debate. Current theories implicate changes in the trigeminovascular system, which is defined as comprising the large intracranial vessels, and in particular, the dural meningeal vessels, the dura mater, and their neural connections.
The anatomical relationships of the dural meningeal arteries to the dura mater and the inner surface of the calvarium are described.
The dural meningeal arteries lie in grooves in the inner table of the calvarium, are encased in the unyielding fibrous dura mater, and are consequently unable to dilate.
The pain of migraine is not related to dilatation of the dural meningeal arteries.
Transcranial color-coded duplex ultrasonography is a new diagnostic procedure allowing the visualization of major intracranial vessels. The purpose of this report is to describe this method and to evaluate its practical potential in the routine examination of basal cerebral arteries. The results from the examination of 96 patients are presented. By means of color coding of Doppler frequencies, the major intracranial vessels were identified by nature of their anatomic location with respect to the echogenic brainstem structures in all subjects. The average maximal systolic velocity was, in the middle cerebral artery, 108 +/- 15 cm/s; in the anterior cerebral artery, 96 +/- 15; in the posterior cerebral artery, 76 +/- 16; and in the basilar artery, 59 +/- 17 cm/s. The determination of the angle between the ultrasonic beam and the examined vessel improved the accuracy of flow velocity measurements in comparison with conventional transcranial Doppler ultrasonography. The exact measurement of blood flow velocity in several segments of the visualized vessel proved helpful in the assessment of pathologic findings, especially in differentiation between a stenosis of the intracranial vessel and a vasospasm.
Transcranial color-coded duplex sonography (TCCD), magnetic resonance angiography (MRA), and computed tomography angiography (CTA) are novel noninvasive or minimally invasive techniques for the study of the intracranial circulation. TCCD is relatively inexpensive and permits bedside examination. It improves the accuracy and reliability of conventional transcranial Doppler studies. The main limitation of TCCD are the ultrasonic windows. They restrict the area of insonation to the major cerebral arteries and the proximal part of its branches, lower the spatial resolution, and may prevent transtemporal insonation. Using MRA, both large and small intracranial arteries and veins can be imaged by selecting the appropriate imaging parameters. MRA provides morphologic information about the cerebral vessels, relying on blood flow as the physical basis for generating contrast between stationary tissues and moving spins. MRA is highly sensitive for the detection of occlusive disease in large intracranial arteries. However, with bright blood techniques the degree of stenosis tends to be exaggerated. Flow direction, eg, in collaterals, can be determined by selective or phase-contrast MRA. Perfusion imaging techniques provide information about blood flow at the capillary level. Diffusion imaging depicts molecular motion. TCCD and MRA used in combination or alone may eliminate the need for intra-arterial digital subtraction angiography (DSA) in most patients studied for occlusive cerebrovascular disease. DSA may be reserved for those patients where there is disagreement among the noninvasive techniques, and for the diagnosis of cerebral aneurysms and arteriovenous malformations. CTA relies on spiral CT technology and intravenous contrast injection. To date, intracranial use has been predominantly for the diagnosis of aneurysms. The role of CTA for the detection of nonaneurysmal intracranial vascular disease has yet to be established.
In 40 patients with unilateral occlusion of the internal carotid artery, using a transcranial Doppler device, blood flow velocity in the ipsilateral ophthalmic and middle cerebral artery was registered. During compression of the ipsilateral common carotid artery a decrease of ophthalmic artery flow velocity was noted in 39 patients (97.5%) and a decrease of middle cerebral artery flow velocity in 8 patients (20%). The average decrease of mean velocity in the middle cerebral artery was 4.5% of the initial value. During compression of the ipsilateral superficial temporal and facial arteries ophthalmic artery flow velocity decreased in 10 patients (25%) and no marked decrease of middle cerebral blood flow was noted. Conclusions. The external carotid artery in most of the patients with internal carotid occlusion is of no significance for cerebral blood supply, but it is the most important source of collateral blood supply to the eye. The maxillary artery, and not superficial temporal and facial as it seemed in periorbital Doppler examinations, is the branch of the greatest collateral value for the eye and brain.
Volumetric flow rates were obtained in an in vivo canine pulsatile flow model using color Doppler ultrasonography (CDUS) and timed collection (TC) over a range which included laminar and turbulent flow. CDUS demonstrated increasing flow disturbance as flow rates increased, with effects on velocity profile, diameter measurements, and flow symmetry. Data comparing CDUS and TC showed marked differences in laminar flow (regression: slope = 1.02; r2 = 0.93; mean error, 11%) and nonlaminar flow (slope = 0.53; r2 = 0.78; mean error, 26%). Assigning the angle of insonation precisely was crucial to measurement accuracy. CDUS quantitates volumetric blood flow with a reasonable degree of accuracy under laminar flow conditions. Visual clues provided by CDUS can help avoid errors associated with deviations from laminar flow.
To determine whether tapping on the superficial temporal artery correctly identifies the ECA during carotid sonography, prospective evaluation of the reflection of the temporal tap on the spectral waveform was recorded and graded as 3+, 2+, 1+, or 0 in each ECA, ICA, and CCA, with 3+ being the most brisk response in each carotid system (ipsilateral CCA, ICA, and ECA). The pattern of response was evaluated in patients with and without hemodynamically significant (> than 50% diameter) stenoses in CCA, ICA, and ECA. The most frequent pattern of response to tapping on the superficial temporal artery was 3+ in the ECA, 2+ in the CCA, and 1+ or 0 in the ICA. This pattern was found in 41% (82/200) of systems overall. Whether or not stenoses were present in any branch of the extracranial carotid system, the strongest response (3+) was found in the ECA (58/200 [87%] with stenosis; 119/200 [89%] without stenosis, and lesser responses in the other arteries: 2+ in the CCA 31/200 [46%] with stenosis; 63/200 [47%] without stenosis, and 1+ or 0 in the ICA 58/200 [87%] with stenosis and 103/200 [77%] without stenosis). This pattern was unaltered by the degree of stenosis in the ECA or in the ICA. In 92.5% of the systems interrogated, the response was greater in the ECA than in the ICA. Tapping on the superficial temporal artery may be used as a reliable method of identifying the ipsilateral ECA even in instances of significant atherosclerotic disease in the ECA, CCA, or ICA.
To examine the effectiveness of percussion of the superficial temporal artery for identification of the external carotid artery (ECA).
The temporal artery tap maneuver was performed on 324 carotid arteries (163 patients). Evidence for transmission of the effect of the temporal tap was sought in the pulsed Doppler ultrasound waveforms of the ECA, common carotid artery (CCA), and internal carotid artery (ICA). The location and severity of stenotic lesions were recorded. The relative amplitudes of the oscillations created by the tap were compared.
The temporal tap effect could be seen in 262 ECAs (81%), 174 CCAs (54%), and 106 ICAs (33%). The tap effect can be seen in the ICA at all grades of ICA disease. When the oscillations were seen in only one of the two major branches, that branch was always the ECA. When the temporal tap effect was found in the ICA, the amplitudes of the oscillations were the same as or greater than those of the ECA in 26% of cases.
Waveform oscillations from the temporal tap maneuver often can be found beyond the ECA in the CCA and ICA. Thus, the temporal tap alone may not reliably distinguish the ECA from the ICA or CCA.
The authors compared the postocclusion hyperemic responses of the brachial artery after occluding blood flow proximal to and distal to the studied area.
Response of the brachial artery to hypoxia was evaluated with duplex Doppler ultrasound in 13 healthy subjects. A pneumatic tourniquet was first positioned 2-5 cm superior to the left elbow, proximal to the area of artery studied. Two hours later the response was remeasured with the tourniquet positioned 2-5 cm inferior to the elbow, distal to the artery studied. Arterial diameter, mean and peak flow velocities, and heart rate were assessed.
No significant differences were observed between measurements of baseline and postischemic arterial diameter, percentage diameter change, baseline mean arterial blood flow velocity, baseline peak arterial blood flow velocity, or postischemic heart rate obtained with proximal occlusion of the artery and those obtained with distal occlusion. In contrast, mean and peak postischemic arterial blood flow velocity and preocclusion heart rate were higher in measurements made during proximal artery occlusion. Significant correlation was found between measurements of percentage change in artery diameter obtained with proximal artery occlusion and those obtained with distal occlusion (r = 0.611, P < .05).
There are no major differences in postischemic changes in brachial artery diameter related to reactive hyperemia between blood flow occlusion applied proximal and distal to the studied area. However, there are significant differences in the mean and peak systolic velocities. Either occlusion site can be used for clinical studies if arterial diameter change is monitored, but if velocity measurements are being compared, a single occlusion site should be chosen.
To define the relationship of the branches of the trigeminal nerve and the infratemporal vessels to the zygomatic arch and medial capsular ligament of the temporomandibular joint (TMJ).
In a study of 20 cadaveric dissections of the infratemporal fossa, measurements were obtained in anterior-posterior and transverse directions to identify the relationship of the trigeminal nerve, carotid artery, internal jugular vein, and middle meningeal artery to the zygomatic arch. The distance from the lateral to the medial aspect of the glenoid fossa was measured to further delineate the proximity of these structures to the medial portion of the capsule of the TMJ.
The mean transverse distance from the zygomatic arch to the middle meningeal artery was 31 mm (range, 21 mm to 43 mm). The mean anterior-posterior distance from the height of the glenoid fossa to the middle meningeal artery was 2.4 mm (-2 mm to 8 mm). The transverse distance from the carotid artery to the zygomatic arch was a mean of 37.5 mm (29 mm to 48 mm) with the mean anterior-posterior distance of -6.5 mm (-21 mm to 6 mm). The mean distance from the internal jugular vein to the zygomatic arch was 38.3 mm (31 mm to 49 mm). The mean anterior-posterior distance was -8.7 mm (-20 mm to 7 mm). The transverse distance from the trigeminal nerve to the arch was a mean distance of 35 mm (24 mm to 46 mm). The mean anterior-posterior distance was 9.2 mm (1 mm to 25 mm). The mean medial to lateral width of the glenoid fossa was 18.7 mm (16 mm to 23 mm).
The arteries, nerves, and veins are close to the medial aspect of the TMJ. A knowledge of these relationships can guide the surgeon on the medial aspect of the TMJ and can help to prevent complications associated with these structures.
To establish normal cerebral blood flow volume by measuring flow volume of the extracranial carotid and vertebral arteries using Doppler ultrasonography in healthy adults.
A prospective study was performed with a group of 96 healthy adults aged 20 to 80 years (48 women, 48 men; mean age of all patients, 49.8 +/- 17.1). The common, external, and internal carotid arteries and the vertebral arteries (CCA, ECA, ICA, and VA, respectively) were examined using Doppler ultrasonography. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and luminal diameters of the vessels were measured, and flow volumes were calculated in all the arteries. The influence of age on these parameters was also investigated.
In the CCA, ICA, and VA, all flow velocities and flow volumes decreased significantly with an increase in age. The luminal diameters of the carotid and vertebral arteries increased significantly with aging, while there was no significant alteration in the RI. The luminal diameters of the CCA, ICA, and ECA were significantly smaller in women than in men. PSV and EDV in the ICA, and EDV in the VA were significantly higher in men. There was no gender-linked difference in flow volumes of the brain-feeding arteries, however, in the ECA flow volumes were significantly higher in women.
Normal cerebral blood flow volume was established by measuring the flow volume of the ECA and VA with Doppler ultrasonography in healthy adults. We believe that these data can be useful in evaluating cases with cerebrovascular disease, which are related to altered cerebral blood flow volume.
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