Deep Temporal Artery Research Articles

Association of Genetic Variants with Postoperative Donor Artery Development in Moyamoya Disease: RNF213 and Other Moyamoya Angiopathy-Related Gene Analysis.

Robust postoperative bypass development is a characteristic of moyamoya disease (MMD); however, genetic factors mediating this phenomenon remain incompletely understood. Therefore, we aimed to elucidate the relationship between postoperative donor artery development and genetic variants. We retrospectively enrolled 63 patients (79 hemispheres) who underwent combined revascularization surgery. Postoperative development of the superficial temporal artery (STA), middle meningeal artery, and deep temporal artery (DTA) was assessed using the caliber-change ratio determined from magnetic resonance angiography measurements. We analyzed RNF213 and 36 other moyamoya angiopathy-related genes by whole-exome sequencing and extracted rare or damaging variants. Thirty-five participants carried RNF213 p.Arg4810Lys (all heterozygotes), whereas 5 had RNF213 rare variants (RVs). p.Arg4810Lys was significantly associated with postoperative DTA development, while age at surgery, hypertension, and hyperlipidemia were inversely associated. Multiple regression analysis revealed that age and p.Arg4810Lys held statistical significance (P = 0.044, coefficient - 0.015, 95% confidence interval (CI) - 0.029 to 0.000 and P = 0.001, coefficient 0.670, 95% CI 0.269 to 1.072, respectively). Those with RNF213 RV without p.Arg4810Lys exhibited a significant trend toward poor DTA development (P = 0.001). Hypertension demonstrated a significant positive association with STA development, which remained significant even after multiple regression analysis (P = 0.001, coefficient 0.303, 95% CI 0.123 to 0.482). Following Bonferroni correction for multiple comparisons, targeted analyses of RNF213 and 36 moyamoya angiopathy-related genes showed a significant association of only RNF213 p.Arg4810Lys with favorable DTA development (P = 0.001). A comprehensive analysis of RNF213, considering both p.Arg4810Lys and RVs, may provide a clearer prediction of postoperative DTA development.

Localization of Maxillary Artery for Cerebral Revascularization: L-Shaped Perpendicular Two-Step Drilling Technique Stretching from the Foramen Ovale to Rotundum

The use of the maxillary artery (MA) as a donor has increasingly become an alternative method for cerebral revascularization. Localization difficulties emerge due to rich infratemporal anatomical variations and the complicated relationships of the MA with neuromuscular structures. We propose an alternative localization method via the interforaminal route along the middle fossa floor. Five silicone-injected adult cadaver heads (10 sides) were dissected. Safe and effective localization of the MA was evaluated. The MA displayed anatomical variations in relation to the lateral pterygoid muscle (LPM) and the mandibular nerve branches. The proposed L-shaped perpendicular 2-step drilling technique revealed a long MA segment that allowed generous rotation to the intracranial area for an end-to-end anastomosis. The first step of drilling involved medial-to-lateral expansion of foramen ovale up to the lateral border of the superior head of the LPM. The second step of drilling extended at an angle approximately 90° to the initial path and reached anteriorly to the foramen rotundum. The MA was localized by gently retracting the upper head of the LPM medially in a posterior-to-anterior direction. Considering all anatomical variations, the L-shaped perpendicular 2-step drilling technique through the interforaminal space is an attainable method to release an adequate length of MA. The advantages of this technique include the early identification of precise landmarks for the areas to be drilled, preserving all mandibular nerve branches, the deep temporal arteries, and maintaining the continuity of the LPM.

Characteristics of donor vessels and cerebral blood flow in the chronic phase after combined revascularization surgery for moyamoya disease

ObjectiveThis study aimed to analyze whether the development of donor vessels after combined revascularization surgery for moyamoya disease (MMD) is related to cerebral blood flow (CBF) changes. MethodsWe retrospectively reviewed the charts of 11 adult (12 hemispheres) and 13 pediatric (19 hemispheres) patients who underwent combined revascularization in our department. The total vessel cross-sectional area (TVA) was the sum of the cross-sectional areas of the superficial temporal, middle meningeal, and deep temporal arteries imaged using time-of-flight magnetic resonance angiography. The ipsilateral relative CBF (RCBF) on the brain surface in the craniotomy area was calculated by single-photon emission computed tomography. ΔTVA and ΔRCBF were defined as the preoperative and postoperative ratios of TVA and RCBF, and their correlations were analyzed in adult and pediatric patients. ResultsThe TVA and RCBF showed a significant increase after surgery, regardless of the age group. However, there was no significant correlation between ΔTVA and ΔRCBF in either the adult or pediatric groups. While the adult group exhibited significantly higher ΔRCBF values compared to the pediatric group (p < 0.01, r = −0.44), the ΔTVA values were higher in the pediatric group compared to the adult group (p = 0.06). ConclusionsIn the chronic phase after combined revascularization surgery for MMD, the development of measurable TVA of donor vessels does not necessarily correlate with an increase in CBF around the craniotomy area.

Deep Temporal Artery Anatomy: Implications for Improving the Safety of Deep Temporal Injections.

Knowledge of the anatomy of the deep temporal artery (DTA) is critical to ensure safe filling of the deep temporal region. However, current treatment guidelines still focus on how to avoid the superficial temporal artery and the middle temporal vein, and an understanding of the safety of avoiding DTA injury is lacking. The purpose of this study was to determine the positioning and course of the DTA to help clinicians safely perform the injection and filling in the temporal region. Computed tomography (CT) scans and dissections of the skulls of 34 fresh frozen cadavers perfused with lead oxide were performed. Reconstruction and trajectory analysis of all DTA branches were performed using Mimics and MATLAB software. In this study, the DTA was identified in all samples, which originated from the maxillary artery of the external carotid artery system. According to image reconstruction and anatomical observations, the distribution of the anterior and posterior branches of the DTA had two different distribution patterns. The anatomical level of the DTA is located between the temporal muscle and the periosteal layer. Compared with observations in previous studies, the anterior branch of the DTA is slightly different, and we found that its course is closer to the frontal area in Asian specimens. The anatomical information on the DTA described in this study may help improve awareness of the safety of temporal injection by aesthetic physicians. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266. .

The Anatomy Study of Temporal Region based on Ultrasound Investigation: A Spatial Structure Study.

With the growing popularity of rejuvenation, people are giving more concerns on their temporal depression which makes them look older and wishing to improve it by injection. The complex structure of the temporal region leads to a higher risk of failed injection. The temporal region is well understood based on cadaver anatomy, but few studies have described its spatial structure. The purpose of this study was to improve the efficacy and safety of temporal injection by studying the spatial structure of the soft tissues and major blood vessels in each layer of the temporal region. A total of 30 volunteers (24 men and 6 women, 60 temporal regions) were investigated. Color Doppler ultrasound was used to measure the thickness of the temporal layers at the selected measurement points (A, B, C, D, E, and F). The maximum thickness of the temporal fat pads was also measured, and the layers, depths and diameters of the major temporal vessels (frontal branch of superficial temporal artery and vein, middle temporal vein and deep temporal artery) were measured. At the various measurement points, the thickness and position of the skin, subcutaneous fat superficial fascia, and temporalis muscle did not differ significantly, whereas the superficial temporal fat pad and deep temporal fat pad differed significantly. The diameter and depth of the superficial temporal artery, superficial temporal vein, and deep temporal artery did not differ significantly, whereas the diameter of the middle temporal vein differed slightly, whereas the depth differed more obviously. The temporal structure is very complex, and understanding the spatial position of each layer of tissue plays an important role in improving the efficacy and safety of temporal filler injection. Ultrasound can help us to understand this information and assist in therapy. Level II.

Ultrasonic hemodynamic changes of superficial temporal artery graft in different angiogenesis outcomes of Moyamoya disease patients treated with combined revascularization surgery.

Combined bypass is commonly used in adult Moyamoya disease (MMD) for revascularization purposes. The blood flow from the external carotid artery system supplied by the superficial temporal artery (STA), middle meningeal artery (MMA), and deep temporal artery (DTA) can restore the impaired hemodynamics of the ischemic brain. In this study we attempted to evaluate the hemodynamic changes of the STA graft and predict the angiogenesis outcomes in MMD patients after combined bypass surgery by using quantitative ultrasonography. We retrospectively studied Moyamoya patients who were treated by combined bypass between September 2017 and June 2021 in our hospital. We quantitatively measured the STA with ultrasound and recorded the blood flow, diameter, pulsatility index (PI) and resistance index (RI) to assess graft development preoperatively and at 1 day, 7 days, 3 months, and 6 months after surgery. All patients received both pre- and post- operative angiography evaluation. Patients were divided into either well- or poorly-angiogenesis groups according to the transdural collateral formation status on angiography at 6 months after surgery (W group or P group). Patients with matshushima grade A or B were divided into W group. Patients with matshushima grade C were divided into P group, indicating a poor angiogenesis development. A total of 52 patients with 54 operated hemispheres were enrolled, including 25 men and 27 women with an average age of 39 ± 14.3 years. Compared to preoperative values, the average blood flow of an STA graft at day 1 postoperation increased from 16.06 ± 12.47 to 117.47± 73.77 (mL/min), diameter increased from 1.14 ± 0.33 to 1.81 ± 0.30 (mm), PI dropped from 1.77 ± 0.42 to 0.76 ± 0.37, and RI dropped from 1.77 ± 0.42 to 0.50 ± 0.12. According to the Matsushima grade at 6 months after surgery, 30 hemispheres qualified as W group and 24 hemispheres as P group. Statistically significant differences were found between the two groups in diameter (p = 0.010) as well as flow (p = 0.017) at 3 months post-surgery. Flow also remained significantly different at 6 months after surgery (p = 0.014). Based on GEE logistic regression evaluation, the patients with higher levels of flow post-operation were more likely to have poorly-compensated collateral. ROC analysis showed that increased flow of ≥69.5 ml/min (p = 0.003; AUC = 0.74) or a 604% (p = 0.012; AUC = 0.70) increase at 3 months post-surgery compared with the pre-operative value is the cut-off point which had the highest Youden's index for predicting P group. Furthermore, a diameter at 3 months post-surgery that is ≥0.75 mm (p = 0.008; AUC = 0.71) or 52% (p =0.021; AUC = 0.68) wider than pre-operation also indicates a high risk of poor indirect collateral formation. The hemodynamic of the STA graft changed significantly after combined bypass surgery. An increased flow of more than 69.5 ml/min at 3 months was a good predictive factor for poor neoangiogenesis in MMD patients treated with combined bypass surgery.

Outcomes after superficial temporal artery-middle cerebral artery anastomosis combined with multiple burr hole surgery and dural inversion synangiosis for moyamoya disease in adults.

Several forms of cerebral revascularization have been carried out to treat moyamoya disease, however, the existing methods are accompanied by a variety of complications. In this study, the authors aimed to evaluate the clinical and angiographic outcomes of a new surgical procedure: superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis combined with multiple burr hole (MBH) surgery and dural inversion synangiosis for the treatment of moyamoya disease in adults. Patients treated for moyamoya disease from August 2019 to July 2021 were retrospectively reviewed. Clinical data, including perioperative complications and follow-up outcomes, were noted. Preoperative and postoperative angiograms were compared, and the diameters of the frontal branch of the superficial temporal artery (F-STA), the deep temporal artery (DTA), the distal superficial temporal artery (STA) before the bifurcation and the middle meningeal artery (MMA) were measured on preoperative and postoperative angiograms. Meanwhile, a Matsushima score was assigned from postoperative angiograms. This study included 66 patients (67 hemispheres). During the follow-up period, a median of 18 (IQR, 13-21) months, no stroke or death occurred in any of the patients. The clinical outcomes were excellent in 27 patients (40.9%), good in 34 patients (51.6%), fair in 4 patients (6.0%), and poor in 1 patient (1.5%); the overall rate of favorable clinical outcomes (excellent and good) was 92.5%. The modified Rankin Scale (mRS) score was significantly improved at follow-up (P < 0.001). There were 41 hemispheres imaged by cerebral angiography after the operation, at a median postoperative interval of 9 (IQR, 8-12) months; among them, 34 (82.9%) hemispheres had Matsushima scores of grade A and grade B. The average postoperative diameters in the STA, DTA and MMA were increased significantly in 41 hemispheres at follow-up (P < 0.001). Sixteen (24.2%) patients suffered from perioperative complications, including focal hyperperfusion syndrome (HS) in 8 (12.2%) patients, cerebral infarction in 3 (4.5%) patients (including one case accompanied by wound infection), cerebral hemorrhage in 2 (3.0%) patients, seizures in 2 (3.0%) patients, and subdural effusion in 1 (1.5%) patient. The procedure of STA-MCA anastomosis combined with MBH surgery and dural inversion synangiosis may be a safe and effective treatment for adult patients with moyamoya disease.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease.

A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1day and 3months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery. We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1day and 3months after surgery. DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P=0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P<0.001). The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

The Deep Temporal Arteries: Anatomical Study with Application to Augmentations Procedures of the Temple.

The aim of this study was to determine the anatomical features of the deep temporal arteries (DTAs) and thereby provide clinical information for the temple augmentation procedure. Forty-two adult hemifaces from 15 Korean and 6 Thai cadavers (12 males, 9 females; mean age at death, 79.6 years) with no history of trauma or surgical procedure on the temple area were used for anatomical study. A detailed dissection was performed to identify the locations of the anterior and posterior deep temporal arteries (ADTA and PDTA) with reference to the vertical plane passing through the zygomatic tubercle. Fifty-eight healthy Korean participants (31 males and 27 females; mean age, 24.7 years) were included in the ultrasonographic study. The distance from the bone to the DTAs was measured at the level of the zygomatic tubercle (HZt ) and the eyebrow (HEb ). The DTAs were not found within 7.2-12.6 mm posterior to the zygomatic tubercle; instead, the locations varied widely at the HEb . The distances between the bone and the ADTA were 1.7± 1.2 mm (mean ± SD) and 1.3± 0.8 mm, and those between the bone and the PDTA were 2.1± 1.2 mm and 2.0± 1.4 mm at HZt and HEb , respectively. Our findings indicate that at HZt , the area 1cm posterior to the zygomatic tubercle may be a safe area for deep temple augmentation procedures. However, because the distribution patterns of the DTAs at HEb and depth of the DTAs are variable, additional care is required to minimize the risks of the procedure.

Pterional Approach: Technical Variations, Functional, and Cosmetic Outcome in a Series of 1000 Patients

INTRODUCTION Most of the versatility of the pterional approach depends on a series of variations progressively reported by several groups, but little emphasized over the years. The present study condenses the technical notes which the authors adopted in their practice to maximize the surgical freedom of the pterional approach, at once lessening the approach-related complication rate. METHODS Data of a series of patients who underwent a pterional approach between January 2011 and May 2021 were retrospectively reviewed focusing on the technical variations compared to the original Yaşargil’s description. The anatomical rationale, technique, and advantages were outlined and validated through the appraisal of functional and cosmetic complications. RESULTS 994 patients were reviewed. Head extension was avoided in the case of anterior clinoidectomy. A single double-layered galea-pericranium flap was used for duraplasty. The submuscular technique, with compulsive preservation of deep temporal fascia and deep temporal arteries, was preferred for temporalis muscle dissection. McCarty keyhole was never used, thus avoiding exposing the orbit if unnecessary. Widening of the superior orbital fissure and thinning of the orbital roof allowed to significantly increase the working area. The average follow-up was 7.2 years. The overall rate of functional and cosmetic complications was 2.1. DISCUSSION In the authors' experience, the gradual adoption of technical variations related to the patient's positioning, soft tissue dissection, bony work, dura opening, and reconstruction allowed to enhance the versatility of the pterional approach concurrently decreasing the risk of functional and cosmetic complications.

Pterional Approach: Technical Variations, Functional, and Cosmetic Outcome in a Series of 1000 Patients

INTRODUCTION&#x0D; Most of the versatility of the pterional approach depends on a series of variations progressively reported by several groups, but little emphasized over the years.&#x0D; The present study condenses the technical notes which the authors adopted in their practice to maximize the surgical freedom of the pterional approach, at once lessening the approach-related complication rate.&#x0D; METHODS &#x0D; Data of a series of patients who underwent a pterional approach between January 2011 and May 2021 were retrospectively reviewed focusing on the technical variations compared to the original Yaşargil’s description. The anatomical rationale, technique, and advantages were outlined and validated through the appraisal of functional and cosmetic complications. &#x0D; RESULTS&#x0D; 994 patients were reviewed. Head extension was avoided in the case of anterior clinoidectomy. A single double-layered galea-pericranium flap was used for duraplasty. The submuscular technique, with compulsive preservation of deep temporal fascia and deep temporal arteries, was preferred for temporalis muscle dissection. McCarty keyhole was never used, thus avoiding exposing the orbit if unnecessary. Widening of the superior orbital fissure and thinning of the orbital roof allowed to significantly increase the working area. The average follow-up was 7.2 years. The overall rate of functional and cosmetic complications was 2.1.&#x0D; DISCUSSION&#x0D; In the authors' experience, the gradual adoption of technical variations related to the patient's positioning, soft tissue dissection, bony work, dura opening, and reconstruction allowed to enhance the versatility of the pterional approach concurrently decreasing the risk of functional and cosmetic complications.

Predictive role of trigeminal ganglion ischemia on scalp survival affected by temporal artery diameters: The first experimental study

Scalp arteries are mainly innervated by trigeminal, facial, and vagal nerves. The ischemic neurodegeneration of the trigeminal ganglion can impede scalp circulation via vasospasm-creating effects. This study was designed to investigate whether there is any link between the vasospasm index of deep temporal arteries and ischemic neuron densities of the trigeminal ganglion after subarachnoid hemorrhage. The study subjects included five normal control rabbits, six sham rabbits, and nine rabbits chosen from a formerly established experimental subarachnoid hemorrhage group created by cisternal homologous blood injection (0.75mL). These rabbits, all male, were followed up for 3 weeks. The trigeminal ganglion and deep temporal artery vasospasm indexes were examined by stereological methods. Ischemic neuron densities of the trigeminal ganglion and vasospasm index values of deep temporal arteries were compared statistically. Postmortem examinations showed important vasospasms of deep temporal arteries, foramen magnum herniations, and neurodegeneration of the trigeminal ganglion. The mean vasospasm index values and degenerated neuron densities of the trigeminal ganglion were determined as 1.03±0.13 and 10±3/mm3 (p > 0.5) in the control group, 1.21±0.18 and 35±9/mm3 in the sham group (p < 0.005 for sham vs. control), and 2.54±0.84 and 698±134/mm3 in the experimental group (p < 0.0005 for sham vs. control and p < 0.00001 for study vs. control). There was an inverse relationship between the vasospasm index values and the degenerated neuronal density of the trigeminal ganglion. The high degenerated neuron density in the trigeminal ganglion had a facilitative effect on temporal artery vasospasm. Trigeminal ganglion neurodegeneration may promote temporal artery vasospasms after subarachnoid hemorrhage, which has not been previously mentioned in the literature.

Topography of the deep temporal arteries and implications for performing safe aesthetic injections.

Several studies have started investigating the safety of temporal rejuvenation using soft tissue fillers. However, as the temporal region is highly vascularized, adverse events due to intravascular injection are of primary concern. The scarcity of treatment guidelines to date have focused primarily on avoiding the superficial and middle temporal arteries. The aim of the present anatomical study was to describe the topography of the deep temporal arteries (DTAs) with reference to superficial landmarks, to aid clinicians who perform temporal injections. The tissue layers of eight fresh-frozen cephalic cadavers were dissected and assessed, bilaterally in the temporal region (N=16). Distance (D) of the anterior (D1 and D3) and posterior (D2 and D4) arteries was measured from (i) the zygomaticofrontal suture line at the lateral orbital rim (D1 and D2) and (ii) the junction of the superior border of the zygomatic arch and lateral orbital rim (D3 and D4). The distance between the anterior and posterior DTAs was also recorded, at the two regions (D5). Bifurcations of the DTAs were observed in 18.75% (3/16) and 12.5% (2/16) of cases, for the anterior and posterior branches, respectively. On average [mean (standard deviation)], D1 (anterior DTA to the zygomaticofrontal suture line at the lateral orbital rim)=1.56cm (0.59); D2 (posterior DTA to the zygomaticofrontal suture line at the lateral orbital rim)=2.98cm (0.70); D3 (anterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim)=1.14cm (0.63); D4 (posterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim)=2.37cm (0.62); and D5 (distance between the anterior and posterior DTAs)=1.54cm (0.68). To help avoid vascular adverse events while performing temporal injections, aesthetic clinicians should be conscientious of safety implications related to the anatomical location of the DTAs and their ramifications.

The branching pattern of the middle temporal artery and the relation with the temporal fascia.

Although the middle temporal artery is used for maxillofacial and otological flap surgeries, the anatomical knowledge of the artery is insufficient to corroborate its usage. This study has investigated the interrelationship between the artery and the temporal fascia to enhance its availability. The middle temporal artery was dissected in ten cadavers, and its spatial relations with the temporal fascia and muscle and the adjacent structures were examined. The middle temporal artery arose behind the mandibular head or neck and in front of the external acoustic meatus. It penetrated the temporal fascia external to the junction between the zygomatic process and the supramastoid crest. The artery gave off a thin branch in the space between the superficial and the deep layers of the fascia and is divided into two branches piercing the deep layer to supply the temporalis. The anterior branch anastomosed with the deep temporal artery; furthermore, it gave off the slender ramus coursing on the base of the zygomatic process to communicate with the masseteric artery. The posterior branch passed along the supramastoid crest, gave off a slender ramus and ascended in the groove of the temporal bone. The branching pattern of the middle temporal artery and its positions relative to the temporal fascia and the landmark structures are helpful in identifying the artery, designing favourable flaps and avoiding unfavourable bleeding during surgery. They are also beneficial in developing the clinical usage of the artery.

Carotid ultrasonography predicts collateral development following combined direct and indirect revascularization surgery in adult ischemic Moyamoya disease

ObjectiveThe relationship between carotid ultrasonographic parameters and postoperative collateral development in adult ischemic moyamoya disease (MMD) patients who received combined direct and indirect revascularization surgery remains unclear. Herein, we investigated the postoperative changes in carotid ultrasonographic parameters in patients with adult ischemic MMD. MethodsWe studied 28 adult ischemic MMD patients (31 hemispheres) who underwent combined revascularization surgery. Patients underwent preoperative and postoperative (within 14 days and 3, 12, and 24 months after surgery) magnetic resonance imaging and carotid ultrasonography. We defined the hemisphere in which all signal intensities of the superficial temporal, middle meningeal, and deep temporal arteries were increased compared with that before surgery on magnetic resonance angiography as well-developed collateral establishment. ResultsPatients with good collateral establishment on MRA at 2-year after surgery had a lower external carotid artery (ECA) pulsatility index (PI) (P = 0.0413) and ECA/internal carotid artery (ICA) pulsatility index (PI) ratio (P = 0.0427) at 3-month post-operation. At 3-month post-operation, a cut-off ECA PI of 1.416 (sensitivity 40.0 %, specificity 92.3 %, area under the curve 0.7282, likelihood ratio 5.20, P = 0.0404) and ECA/ICA PI ratio of 0.8768 (sensitivity 50.0 %, specificity 92.31 %, area under the curve 0.7308, likelihood ratio 6.50, P = 0.0415) provided reliable values for good prediction of collateral development at 2 years after revascularization. ConclusionECA/ICA PI ratio and ECA PI at 3-month after surgery can be one of the indicators for predicting future well-developed neovascularization on MRA and better outcome in patients with adult ischemic MMD who received combined direct and indirect revascularization surgery.

Three-Dimensional Computed Tomography Scanning of Temporal Vessels to Assess the Safety of Filler Injections.

Temple filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon. This study aimed to investigate the anatomy of the temporal vessels and provide a more accurate protocol for temple filler injection. Computed tomography (CT) scans of 56 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3-dimensional (3D) images of the temporal vessels described by a coordinate system based on the bilateral tragus and right lateral canthus. In the XOY plane, the superficial temporal artery (STA), middle temporal artery (MTA), zygomatico-orbital artery (ZOA), posterior branch of the deep temporal artery (PDTA), and lateral margin of the orbital rim divide the temple into 4 parts (A, B, C, and D). The probabilities of the STA, MTA, ZOA, and PDTA appearing in parts A, B, C, and D were 30.73%, 37.06%, 39.48%, and 77.18%, respectively. In 3D images, these vessels together compose an arterial network that is anastomosed with other vessels, such as the external carotid, facial, and ocular arteries. 3D CT images can digitally elucidate the exact positions of temporal vessels in a coordinate system, improving the safety of temple filler injections in a clinical setting.

Long-Term Patency and Final Structure After Superficial Temporal Artery–Middle Cerebral Artery Bypass Surgery: A Retrospective Study

To investigate long-term bypass patency and final structure for patients who underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass. This study retrospectively evaluated 20 patients who underwent STA-MCA bypass and had 2-year follow-up with cerebral angiography. Patients were divided into internal carotid artery occlusion (n= 11) and MCA occlusion or stenosis (n= 9) groups, and diagnosis was either arteriosclerotic (n= 14) or nonarteriosclerotic (n= 6) disease. Final bypass formation was examined with cerebral angiography at 2 years postoperatively. Diameters of the STA, middle meningeal artery (MMA), and deep temporal artery (DTA) were measured at preoperative angiography and at 2-year follow-up. No significant differences in STA, MMA, and DTA diameters were reported between the internal carotid artery versus MCA group. For patients with arteriosclerotic disease, thicker STA diameters were noted on preoperative angiography. For patients with nonarteriosclerotic disease, MMA and DTA dilatation was noted on 2-year follow-up imaging. For patients with arteriosclerotic disease, all direct bypasses were patent at 2 years. For patients with nonarteriosclerotic disease, remarkable angiogenesis was demonstrated. Long-term patency of a direct bypass may be correlated with arteriosclerotic or nonarteriosclerotic etiology. An indirect bypass route may develop in patients with nonarteriosclerotic disease; therefore, it is important to create a foundation for an indirect bypass with MMA and DTA preservation during craniotomy. In 2 patients with nonarteriosclerotic disease, STA remained the primary bypass foundation; however, the technique resembled novel angiogenesis after encephaloduroarteriosynangiosis and not direct STA-MCA bypass. Therefore, final bypass structure might be affected by disease etiology.

Safe Zones for Temporal Muscle Hook Retraction: A Technical Note

The temporal muscle (TM) needs to be dissected and reflected downward in some anterolateral cranial approaches, and failing to preserve its integrity could have severe functional and cosmetic consequences. Most articles focus on techniques to prevent vascular injury during retrograde dissection or techniques to preserve the facial nerve; however, information on how to take care of the muscle during hook retraction is limited. We presented an anatomic study of vascularization of the TM, and we established safe areas for muscular hook retraction. We dissected 16 TMs in 8 cadaveric heads. The TM was reflected downward, and we measured the distance between the anterior branch of the posterior deep temporal artery (PDTA) and the frontozygomatic suture and the distance between the posterior branch of the PDTA and the external auditory meatus projection. The average distance between the anterior branch of the PDTA and the frontozygomatic suture was 19.5 mm (range, 14-26 mm). The average distance between the posterior branch of the PDTA and the external auditory canal was 37.1 mm (range, 31-43 mm). We established 2 safe zones for hook placement: an anterior safe zone 14 mm posterior to the frontozygomatic suture and a posterior safe zone 30 mm anterior to the external auditory meatus. We delimited 2 safe zones for hook placement during TM retraction aiming to avoid direct vascular damage in anterolateral cranial approaches.

Abstract TP488: Postoperative Remodeling of Donor Arteries on MR Angiography Can Predict Development of Surgical Collaterals in Moyamoya Disease

Object: The calibers of donor arteries can change dynamically after bypass surgery in moyamoya disease (MMD). The present study aimed to evaluate the cut-offs of caliber changes in donor arteries associated with good surgical revascularization and to assess the impact of clinical factors potentially related to bypass development. Methods: We studied 71 hemispheres of 30 adults and 16 children with MMD, who underwent combined revascularization. We quantitatively measured the calibers of the superficial temporal artery (STA), deep temporal artery (DTA), and middle meningeal artery (MMA) with magnetic resonance angiography (MRA) source images and calculated the postoperative caliber change ratios (CCRs), to assess direct and indirect bypass development. They were compared with the findings of digital subtraction angiography, in which revascularization areas were categorized into 3 groups (poor, good, and excellent). Results: In both adult and pediatric hemispheres, median STA and DTA CCRs were higher in better revascularization groups (p &lt; 0.05), while MMA CCRs were not significantly different among the groups. Receiver operation characteristic analysis revealed that the cut-off of &gt;1.1 and &gt;1.3 STA CCRs were associated with good direct revascularization in adult and pediatric hemispheres, respectively. The cut-off of &gt;1.6 and &gt;1.2 DTA CCRs were associated with good indirect revascularization in adult and pediatric hemispheres, respectively. Considering these cut-off values, STA and DTA CCRs showed high median values, irrespective of age, severity of cerebrovascular reserve, disease stage, and disease onset type. Conclusions: Caliber changes in STA and DTA can be easily measured by MRA, which could be indicators of direct and indirect bypass development. The combined bypass procedure could maximize revascularization in both adults and children with MMD.

The temporalis muscle and its relationship to the accessory attachments and the main pedicle—a cadaveric study

Lengthening temporalis myoplasty, described by Daniel Labbe in 1997, is a facial reanimation procedure for the treatment of facial nerve palsy. It involves the mobilization of temporalis muscle antero-inferiorly, and the insertion of its tendon at the nasolabial fold-oral commissure region. Knowledge of the temporalis muscle is crucial in performing this procedure; however, previous anatomical studies are limited. This study on cadavers, aimed to describe the anatomical location of the temporalis muscle insertion in relation to the adjacent structures, and its main pedicle to aid surgeons in performing this procedure. Twenty-four temporalis muscles were dissected in 12 fresh frozen cadavers. The anatomical location of the temporalis muscle insertion, accessory attachments, the emergence of the posterior deep temporal artery, and the distance of sliding movements from the coronoid process to the nasolabial fold were recorded. In addition to its origin from the temporalis fossa and its insertion at the coronoid process, the temporalis muscle was found to have multiple accessory attachments to adjacent structures. These findings explain the challenges in performing the sliding action without releasing the accessory attachments to the masseter and pterygoid muscles. The deep posterior temporal artery is located inferoposteriorly in relation to the muscle. Therefore, the muscle elevation maneuver performed without direct vision can be done with minimal risk to the muscle pedicle. The knowledge of temporalis muscle insertion, its accessory attachments, and its main pedicle will facilitate surgeons in performing the lengthening temporalis myoplasty more confidently.