Development of the external carotid artery system including the middle temporal artery after direct-indirect revascularization surgery for moyamoya disease.

BACKGROUND: The aim of this study was to clarify when and from which blood vessels indirect revascularization develops after combined revascularization surgery for moyamoya disease and how the donor vessels that undergo direct revascularization change in the medium to long term. In particular, we focused on the middle temporal artery (MTA), which has not received much attention in indirect revascularization surgery for moyamoya disease until now. METHODS: We targeted 20 sides that were suitable for evaluating the diameter of the external carotid artery system involved in combined revascularization surgery among moyamoya disease patients who underwent a composite revascularization procedure utilizing a 'U'-shaped skin incision encircling the parietal branch of the superficial temporal artery (STA) at our institution from 2018 to 2023. We identified the STA parietal branch, MMA, DTA, and MTA in the TOF source MR images acquired preoperatively and three and six months after surgery; measured the long and short diameters of each blood vessel; approximated the blood vessel shape as an ellipse, and calculated its cross-sectional area. RESULTS: The cross-sectional areas of the MMA, DTA, and MTA involved in indirect revascularization significantly increased compared to presurgery three months after surgery, and this trend continued six months after surgery, but no significant change was observed between three and six months after surgery. There were no cases in which the MTA was clearly confirmed before surgery in the TOF reconstructed images, but the MTA was clearly confirmed in 55% (11/20 cases) of hemispheres three months after surgery and in 85% (17/20 cases) of hemispheres six months after surgery. The crosssectional area of the STA parietal branch, which was the donor for direct revascularization, had increased by more than 150% compared to before surgery in 55% (11/20 cases) of hemispheres three months after surgery. CONCLUSIONS: Indirect revascularization can be expected three months after combined revascularization surgery for moyamoya disease. The MTA, which has not received much attention in terms of indirect revascularization for moyamoya disease patients thus far, was found to be a useful blood flow source for indirect revascularization in combined revascularization surgery for patients with moyamoya disease. Whether or not the cross-sectional area of the superficial temporal artery used as a donor for direct revascularization increased in the medium to long term varied on a case-by-case basis.

The effect of arterial spin labeling MR angiography (ASL-MRA) in visualizing the branches of external carotid artery.

This study aimed to assess the performance of arterial-spin labeling MRA (ASL-MRA) for visualizing the external carotid artery (ECA) branches in comparison with time-of-flight MRA (TOF-MRA) and CT angiography (CTA). We retrospectively selected 31 consecutive patients, who underwent both MRAs and CTA, prior to the intra-arterial chemoradiotherapy (IACRT) for head and neck cancer. Four patients underwent IACRT bilaterally, so we analyzed 35 ECAs. Pseudo-continuous, three-dimensional ASL using a turbo field echo sequence was acquired. For the TOF-MRA and CTA, clinically used parameters were applied. Two observers evaluated each ECA branch with reference to the angiogram at the IACRT, using five-point scale, in consensus. Friedman test for multiple comparisons was applied. ASL-MRA and CTA better visualized the superior thyroid, lingual, facial, submental, transverse facial, and internal maxillary arteries (IMAs) better than TOF-MRA (p < 0.05). In addition, CTA was superior to ASL-MRA in visualizing only submental artery among these arteries (p = 0.0005). Alternatively, the ASL-MRA was superior for visualizing the middle meningeal artery (MMA) and IMA, compared to the CTA (p = 0.0001 and 0.0007, respectively). ASL-MRA was superior to the TOF-MRA and similar to the CTA in visualizing most of ECA branches. Furthermore, ASL-MRA can better visualize the periphery of MMA and IMA than CTA.

The retromandibular loop of the external carotid artery.

BACKGROUND: The external carotid artery (ECA) is a major artery of the head and neck. Although numerous studies describe the variability of ECA branches, the course variation of the ECA was seemingly overlooked. It was aimed to study the morphological possibilities of the retromandibular segment of the ECA. METHOD: A retrospective study was performed on 60 computed tomography angiograms of 26 male and 31 female adult patients. Three types of retromandibular ECA were defined: type 1 - the ECA has a straight course deep to the anatomical plane of the ramus of the mandible; type 2 - the ECA makes a retromandibular loop directed laterally, extending externally to the anatomical plane of the ramus of the mandible; and type 3 - the retromandibular loop directed laterally reaches just behind the posterior margin of the ramus of the mandible. RESULTS: Type 1 was found in just 43.33%, type 2 in 18.33%, and type 3 in 38.33% of 120 sides cases. On the right, type 1 was significantly associated with the male gender, and type 3 with the female gender (Pearson Chi2=10.9, p=0.004). On the left, there were no statistically significant associations (Pearson Chi2=3.5, p=0.153). In 20 cases, the retromandibular course of the ECA was asymmetrical; in 21 cases, type 1 was recorded bilaterally; in 5 cases, type 2 was bilaterally symmetrical; and in 14 cases, type 3 was found bilaterally. CONCLUSION: These previously undocumented types of ECA are relevant during parotid surgery and should be investigated preoperatively on a case-by-case basis.

A novel system for evaluating collateralization of the external carotid artery after cerebral revascularization in moyamoya disease.

OBJECTIVE: The objective of this retrospective study was to establish a novel system for evaluating collateralization of the external carotid artery in patients with moyamoya disease (MMD) following direct and indirect revascularization surgeries. METHODS: The authors conducted a retrospective analysis of 456 patients diagnosed with MMD who underwent direct and indirect revascularization procedures at Beijing Tiantan Hospital, Capital Medical University, between January 2015 and May 2023. Using a newly proposed digital subtraction angiography (DSA)-based evaluation system, the authors assessed collateralization angiogenesis objectively and in a standardized manner. RESULTS: The authors' findings indicated that there was no significant difference in collateralization angiogenesis between patients undergoing direct or indirect cerebral revascularization (p = 0.702). However, after cerebral revascularization, patients with ischemic MMD exhibited significantly higher collateralization angiogenesis compared with those with hemorrhagic MMD (p = 0.007). Children with MMD demonstrated higher angiogenesis levels than adults (p < 0.001), but subgroup analysis showed age-specific variations. In adults, collateralization angiogenesis was significantly greater in those with ischemic MMD (p = 0.006), whereas in children, no significant difference was noted between ischemic and hemorrhagic MMD (p = 0.962). Furthermore, regardless of MMD type, direct and indirect revascularization methods yielded similar collateralization angiogenesis (p = 0.962 and p = 0.963, respectively). Importantly, the Matsushima grading system revealed significant differences in angiogenesis in patients with ischemic MMD (p < 0.001). CONCLUSIONS: The newly introduced DSA-based evaluation system offers an objective and standardized method for assessing collateralization angiogenesis in MMD. This study supports the efficacy of both direct and indirect revascularization surgical procedures and highlights distinct pathophysiological processes of ischemic and hemorrhagic disease subtypes. These findings contribute to a better understanding of surgical outcomes and aid in the selection of appropriate treatment strategies for patients with MMD.

Selective elevation in external carotid artery flow during acute gravitational transition to microgravity during parabolic flight.

This study sought to determine to what extent acute exposure to microgravity (0 G) and related increases in central blood volume (CBV) during parabolic flight influence the regional redistribution of intra and extra cranial cerebral blood flow (CBF). Eleven healthy participants performed during two parabolic flights campaigns aboard the Airbus A310-ZERO G aircraft. The response of select variables for each of the 15 parabolas involving exposure to both 0 G and hypergravity (1.8 G) were assessed in the seated position. Mean arterial blood pressure (MAP) and heart rate (HR) were continuously monitored and used to calculate stroke volume (SV), cardiac output ([Formula: see text]), and systemic vascular resistance (SVR). Changes in CBV were measured using an impedance monitor. Extracranial flow through the internal carotid, external carotid, and vertebral artery ([Formula: see text]ICA, [Formula: see text]ECA, and [Formula: see text]VA), and intracranial blood velocity was measured by duplex ultrasound. When compared with 1-G baseline condition, 0 G increased CBV (+375 ± 98 mL, P = 0.004) and [Formula: see text] (+16 ± 14%, P = 0.024) and decreased SVR (-7.3 ± 5 mmHg·min·L-1, P = 0.002) and MAP (-13 ± 4 mmHg, P = 0.001). [Formula: see text]ECA increased by 43 ± 46% in 0 G (P = 0.030), whereas no change was observed for CBF, [Formula: see text]ICA, or [Formula: see text]VA (P = 0.102, P = 0.637, and P = 0.095, respectively).NEW & NOTEWORTHY Our findings demonstrate that in microgravity there is a selective increase in external carotid artery blood flow whereas global and regional cerebral blood flow remained preserved. To what extent this reflects an adaptive, neuroprotective response to counter overperfusion remains to be established.

The Extent of Tumor Invasion and Therapeutic Embolization Are Associated with Recurrent Hemorrhage in Patients with External Carotid Artery Blowout Syndrome.

PURPOSE: To explore the optimal strategies of therapeutic embolization for patients with carotid blowout syndrome in the external carotid artery (ECA), who may also present with arterial tumor invasion or necrosis extending to the internal carotid artery (ICA) or common carotid artery (CCA). MATERIALS AND METHODS: The study included 110 patients with ECA blowout between 2005 and 2022. Antecedent cross-sectional imaging features were examined, including tumor size, extent of arterial invasion, and air-containing necrosis. Patients were divided into Groups 1 (n = 53, simultaneous ICA/CCA invasion + ECA therapeutic embolization), 2 (n = 18, simultaneous ICA/CCA invasion + ECA-ICA/CCA therapeutic embolization), and 3 (n = 39, no ICA/CCA invasion + ECA therapeutic embolization). Kaplan-Meier and multivariable Cox regression analyses were performed to evaluate associations of clinical, imaging, and therapeutic embolization characteristics with recurrent bleeding. RESULTS: Multivariable Cox regression revealed that Group 1 was independently associated with a higher risk of recurrent bleeding than that in Group 2 (adjusted hazard ratio, 6.3; 95% CI, 1.7‒23.4; P = .005) and Group 3 (adjusted hazard ratio, 3.8; 95% CI, 1.8‒8.3; P = .001). In the subgroup with simultaneous ICA/CCA invasion, air-containing necrosis around the ICA/CCA was independently associated with recurrent bleeding after therapeutic embolization of the ECA (adjusted hazard ratio, 5.0; 95% CI, 1.8‒13.6; P = .002). CONCLUSIONS: In patients with ECA blowout treated with therapeutic embolization, there was a lower risk of recurrent bleeding when the extents of arterial invasion and therapeutic embolization were concordant. Air-containing necrosis around the ICA/CCA was associated with recurrent bleeding, so extensive therapeutic embolization to the ICA/CCA should be evaluated in such patients.

Preoperative Embolization of Primary Juvenile Nasopharyngeal Angiofibroma: Is Embolization of Internal Carotid Artery Branches Necessary?

PURPOSE: To determine the effects of blood supply from internal carotid artery (ICA) on the surgical outcomes of primary juvenile nasopharyngeal angiofibroma (JNA) after transarterial embolization (TAE). METHODS: A retrospective analysis was performed on primary JNA patients who underwent TAE and endoscopic resection in our hospital between December 2020 and June 2022. The angiography images of these patients were reviewed, and then they were divided into ICA + external carotid artery (ECA) feeding group and ECA feeding group according to whether the ICA branches were part of the feeding arteries. Tumors in ICA + ECA feeding group were fed by both ICA and ECA branches, while tumors in ECA feeding group were fed by ECA branches alone. All patients underwent tumor resection immediately after ECA feeding branches embolization. None of the patients underwent ICA feeding branches embolization. Data on demographics, tumor characteristics, blood loss, adverse events, residual and recurrence were collected, and case-control analysis was performed for the two groups. Differences in characteristics between the groups were tested using Fisher's exact and Wilcoxon tests. RESULTS: Eighteen patients were included in this study: nine in ICA + ECA feeding group and nine in ECA feeding group. The median blood loss was 700 mL (IQR 550-1000 mL) in ICA + ECA feeding group versus 300 mL (IQR 200-1000 mL) in ECA feeding group, with no significant statistical difference (P = 0.306). Residual tumor was found in one patient (11.1%) in both groups. Recurrence was not observed in any patient. There were no adverse events from embolization and resection in either group. CONCLUSION: The results of this small series suggest that the presence of blood supply from ICA branches in primary JNA has no significant effect on intraoperative blood loss, adverse event, residual and postoperative recurrence. Therefore, we do not recommend routine preoperative embolization of ICA branches. LEVEL OF EVIDENCE: Level 4, Case-control.

Congenital external carotid-internal carotid artery anastomosis: a report of three cases and literature review.

PURPOSE: Congenital external carotid-internal carotid artery (EC-ICA) anastomosis is a cervical arterial variation that was initially reported, based on anatomic dissection, from Japan in 2000. The purpose of this report is to show the characteristic radiological findings of this extremely rare cervical arterial variation. METHODS: We analyzed nine cases, including six previously reported cases and three cases that we recently experienced. Three of the six previously reported cases were from Japan, and the remaining three cases were from Korea. MR angiography (4), CT angiography (2), catheter angiography (2) and autopsy (1) were used as diagnostic modalities. RESULTS: The study population included eight men and one woman. Anastomosis was seen on the left side in seven cases and the right side in two cases, and it was located at the level of the C1/2-C2/3 intervertebral space. In all cases, ECA was larger than the ICA at the level of their origins. In four cases, the ICA was extremely small in caliber. In one case, the ICA may have been occluded postnatally, and its configuration was similar to that of the nonbifurcating cervical carotid artery (CCA). With the exception of this occluded case, the carotid bifurcation and EC-ICA anastomosis formed a large arterial ring in all cases. CONCLUSION: EC-ICA anastomosis can be regarded as a variant of the nonbifurcating CCA because if the most proximal segment of the small ICA is occluded, nonbifurcating CCA may form. EC-ICA anastomosis is located between the C1/2-C2/3 intervertebral space and may be formed by the remnants of the proatlantal artery I.

Is the origin of the superior thyroid artery consistent? A systematic review of 5488 specimens.

PURPOSE: The superior thyroid artery (STA) point of origin is strongly debated with controversial results among studies. External carotid artery (ECA), carotid bulb, and common carotid artery (CCA) have been presented as points of origin with variable percentages among authors. We conducted a systematic review of all existing studies that included cadaveric, surgical, and angiographic specimens and recorded the origin of STA according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. MATERIALS AND METHODS: Fifty-two studies, with an overall of 5488 specimens were included. RESULTS: Our results indicated ECA as the most common site of origin (55.0 %) followed by carotid bifurcation at 27.5 % and CCA at 15.0 %. Absent STA or branching from the internal carotid artery (ICA) was an extremely rare finding. We proposed a new simple classification system based on our results. CONCLUSIONS: The huge variability in the branching pattern of STA makes head and neck surgery and radiographic interventions challenging and poses the integrity of STA at risk. Therefore, we strongly recommend preoperative angiographic studies for STA identification to prevent an intraoperative iatrogenic injury.

Revisiting carotid endarterectomy: Neobulb technique using external carotid artery as a patch.

OBJECTIVES: This study describes an alternative carotid bifurcation endarterectomy technique in which the external carotid artery is used as a suture patch. METHODS: Charts of ten patients with atherosclerotic carotid stenosis that were treated using the neobulb technique between 2002 and 2019 were reviewed. RESULTS: No major surgical adverse event was observed in the postoperative assessments. No postoperative common or internal carotid stenosis was observed in the mid- or long-term follow-up. CONCLUSIONS: The neobulb technique allows carotid endarterectomy closure without a synthetic or venous patch, using the external carotid artery as an autologous patch, while preserving distal flow into the external carotid artery branches.

External carotid artery to ophthalmic artery flow associated with internal carotid artery stenosis.

PURPOSE: One of the most devastating complications of facial filler injection is sudden ischemic blindness. However, its mechanisms and predisposing factors are poorly understood. The purpose of this study was to investigate the prevalence of external carotid artery (ECA) to ophthalmic artery (OA) anterograde flow in patients with internal carotid artery (ICA) stenosis and in a control population without carotid disease. METHODS: In this cross-sectional cohort study, two groups of patients who underwent catheter cerebral angiography over a 5-year period were identified: patients with symptomatic ICA stenosis and a control group of patients with refractory epistaxis undergoing embolization. Angiograms were reviewed by an interventional neuroradiologist. The primary outcome measure was the presence of ECA to OA flow, defined as choroidal blush before filling of the circle of Willis. Secondary outcome measures included the percentage and location of ICA stenosis and ECA anastomotic branches involved. RESULTS: The study included 149 patients with ICA stenosis and 69 control patients. ECA to OA flow was more prevalent in patients with ICA stenosis (34.9%) compared to controls (2.9%) (p < .001). Logistic regression demonstrated that for each 10% increase in ICA stenosis over 70%, there was 2.8 times increased risk of ECA to OA flow (p < .001). CONCLUSIONS: ECA to ICA anterograde flow can be demonstrated in approximately 3% of control patients and in over 1/3 of patients with symptomatic carotid stenosis. This provides a plausible pathway for small filler particles to pass with blood flow from the facial to the ophthalmic circulation.

Multidetector computed tomography (MDCT) angiography in the evaluation of external carotid artery.

BACKGROUND: Knowledge about anatomical variants of the external carotid artery is crucial in head and neck surgery and interventional technique. This work aimed to present the frequency of regular and another variant of the external carotid artery using 128 multidetector computed tomography (MDCT) angiography. MATERIALS AND METHODS: This retrospective study included 120 patients in our university hospital between April 2017 and October 2021. They were 65 men and 55 women (mean age, 45.6 years; range, 18-65 years). They were angiofibroma (10 patients), cerebral stroke (28 patients), partial glossectomy (13 patients), submandibular gland excision (12 patients), parotidectomy (17 patients), mandibulectomy (5 patients), and a thyroidectomy (35 patients). We retrospectively analyzed the level and branches of external carotid arteries on both sides of 120 patients. RESULTS: According to the level of bifurcation; the external carotid artery originated at the level of the upper border of the thyroid cartilage in 164/240 cases (68.3%), and a higher level was detected in 76/ 240 cases (31.7%). The lower level of origin of the external carotid artery was not detected. The superior thyroid, facial, and lingual arteries originated from separate branches of external carotid arteries in 173/240 cases (72.1%). At the same time, the facial arteries originated with lingual arteries in a common trunk in 67/240 cases (27.9%). CONCLUSION: MDCT angiography is a valuable noninvasive diagnostic tool for evaluating the external carotid artery and its branches.

Utility of carotid ultrasound on prediction of 1-year mortality in emergency department patients with neurological deficits: A 10-year population-based cohort study.

BACKGROUND: This study aimed to investigate the association between the carotid ultrasound results and 1-yr mortality of patients with neurological deficits in the emergency department (ED). METHODS: This study included patients with neurological symptoms who presented to the ED between January 1, 2009 and December 31, 2018, and underwent sonographic imaging of the bilateral carotid bulb, common carotid artery (CCA), internal carotid artery (ICA), and external carotid arteries. A stenosis degree of >50% was defined as significant carotid stenosis. Carotid plaque score (CPS) was calculated by adding the score of stenosis severity of all segments. The association between carotid ultrasound results and 1-yr mortality was investigated using the Cox regression model. RESULTS: The analysis included 7,961 patients (median age: 69 yr; men: 58.7%). Among them, 247 (3.1%) passed away from cardiovascular (CV)-related causes, and 746 (9.4%) died within a year. The mortality group presented with more significant carotid stenosis of the carotid bulb, CCA, or ICA and had a higher median CPS. A higher CPS was associated with a greater 1-yr all-cause mortality (adjusted hazard ratio [aHR] = 1.08; 95% confidence interval [CI] = 1.03-1.13; p = 0.001; log-rank p < 0.001) and CV-related mortality (aHR = 1.13; 95% CI = 1.04-1.22; p = 0.002, log-rank p < 0.001). Significant stenosis of either carotid artery segment did not result in a higher risk of 1-yr mortality. CONCLUSIONS: We comprehensively investigated the utility of carotid ultrasound parameters on predicting mortality in this 10-yr population-based cohort, which included over 7,000 patients with acute neurological deficits presented to the ED. The result showed that CPS could be used as risk stratification tools for 1-yr all-cause and CV mortality.

Fenestrated Maxillary Artery.

The external carotid artery divides terminally into the superficial temporal and maxillary arteries (MA), deep to the base of the neck of the mandible. Arterial fenestrations are commonly found in the vertebrobasilar and internal carotid systems but are rarely encountered, or reported, in the external carotid artery system. The archived computed tomography angiograms of a 70-year-old male patient were observed anatomically. Inferior to the posterior end of the lateral pterygoid muscle was found a fenestrated segment of the MA, oriented mediolaterally. The middle meningeal artery left the superior arm of that fenestration. The inferior arm of the fenestration gave off a temporoalveolar trunk, further divided into posterior deep temporal and inferior alveolar arteries. The MA fenestration and the temporoalveolar trunk are rare variations of the MA at the entrance in the infratemporal fossa. These make the MA prone to iatrogenic lesions during different surgical procedures addressed to this region.

Endovascular embolisation of external carotid artery system haemorrhage in radiated nasopharyngeal carcinoma.

PURPOSE: To review the effectiveness and safety of embolisation in managing haemorrhage from the external carotid artery (ECA) system in radiated nasopharyngeal carcinoma (NPC) patients. METHODS: Radiated NPC patients who presented with severe oronasal bleeding and underwent digital subtraction angiography that excluded blowouts from the internal carotid artery from 2011 to 2021 were reviewed. Those who subsequently underwent embolisation of the ECA system were analysed for technical success rate, post-embolisation re-bleeding rate and complications. RESULTS: Seventeen embolisations were performed in fifteen patients during the 10-year period. The technical success rate was 100%, however the early haemostatic rate (no re-bleed within 7 days of embolisation) was 70.6% (12/17) and the overall long-term haemostatic rate was 58.8% (10/17). The re-bleed rates of targeted and empiric embolisations were 33.3% (3/9) and 50.0% (4/8), respectively. The re-bleed rates with liquid agents, coils and particles were 0% (0/7), 33.3% (1/3) and 85.7% (6/7), respectively. Amongst the embolisations utilising liquid agents, 71.4% (5/7) were targeted, distal embolisations. All re-bleeds underwent surgical ligation or repeat embolisation; half of them further experienced recurrent bleeding. There were no significant complications with embolisation. CONCLUSION: Although embolisation of the ECA system in NPC has a high technical success rate and is safe, re-bleeding appears to be common. Targeted, distal embolisation with liquid embolics appear to have good haemostatic effect. Clinicians should be aware that patients may need repeated procedures to secure haemostasis.

Coexistence of external carotid artery embolus and internal carotid artery occlusion in acute ischemic stroke: An indicator of cardioembolic etiology?

OBJECTIVES: This study aims to evaluate whether the presence of an external carotid artery embolism accompanying internal carotid artery occlusion may contribute to identifying the etiology of internal carotid artery occlusion in the early period. MATERIAL AND METHODS: The presence of external carotid artery embolism was evaluated in 117 patients who were adjudicated for internal carotid artery occlusion based on digital subtraction angiography images. RESULTS: Embolus in the external carotid artery was detected in 8 (6.8%) of the 117 patients with internal carotid artery occlusion (7 (87.5%) patients were found to have tandem and 1 (12.5%) patient had carotid T occlusion). In all of these patients, the thrombus was of embolic origin. Evaluation of the etiology revealed cardioembolic etiology in 4 patients and dissection in 1 patient, and the cause could not be determined in the remaining 3 patients. Patients with external carotid artery embolism accompanying an internal carotid artery occlusion had significantly higher The National Institutes of Health Stroke Scale scores at admission and significantly lower recanalization success compared to those without external carotid artery embolism (p = 0.009, p = 0.01). In the comparison of prognosis, poorer prognosis was observed in those with external carotid artery embolism, although without a statistically significant difference (p = 0.07). CONCLUSIONS: This study observed that the etiology was mostly embolic in patients with external carotid artery embolism accompanying an internal carotid artery occlusion, most of whom were found to have tandem embolic occlusion, and cardiac origin appeared to be the prominent etiology of stroke.

Geometric morphometric study of anterior branches of external carotid artery and carotid bifurcation by 3D-CT angiography.

PURPOSE: The aim of our study was to determine the variations of the anterior branches of the external carotid artery (ECA) and investigate the morphometric and geometric features of the anterior branches of the ECA and carotid bifurcation (CB). METHODS: A total of 563 ECAs were included from 288 patients in the study. Classification and exit angles of anterior branches of ECA and determination of vertebral levels of CB and anterior branches were performed. RESULTS: The anterior branch variants of the ECA were observed in 8 different subgroups. The most common variations were type Ia 42.3% (n = 120) on the right and type Ib 40.9% (n = 114) on the left. When looking at the vertebral levels, CB was detected at C4 level in 32.9% of total ECAs (n = 185), STA was at C4 level in 33.4% of total ECAs (n = 188), LA was at C3 level in 50.1% of total ECAs (n = 282), and FA was at C2 level in 37.3% of total ECAs. The mean CB angle in all cases was 59.93° ± 16.04. In the anterior branches of the ECA in cases belonging to the Type I group, the widest angle belonged to FA (R = 116.88 ± 27.04°, L = 110.32° ± 25.94). CONCLUSION: In conclusion, a new classification of the variations of the anterior branches of the ECA was made on the basis of the CTA images to gain more practicality in surgical procedures. This study revealed for the first time the angular and level relationship between CB and ECA anterior branches.

External Carotid Artery-Related Adverse Events at Extra-Intra Cranial High Flow Bypass Surgery Using a Radial Artery Graft.

OBJECTIVE: Placing an extracranial-intracranial (EC-IC) high-flow bypass using a radial artery (RA) graft plus internal carotid artery (ICA) trapping or ligation is an option for treating patients expected to be at high risk for complications by direct surgical treatment of the ICA. We focused on the anastomosis between the external carotid artery (ECA) and the RA graft in the cervical region and present adverse events and salvage procedures. METHODS: EC-IC high-flow bypass procedures using an RA graft were performed to treat 87 consecutive patients. The ECA diameter at the midpoint of the planned ECA-RA anastomosis and the non-branched length of the ECA were measured on preoperative angiograms. To study adverse events related to ECA-RA anastomoses, we reviewed the patients' surgical records and intraoperative videos. RESULTS: In 11 patients (12.6%) we encountered adverse events during anastomosis between the ECA and RA. The rate of ECA dissection was significantly higher in male patients (4 of 17; 23.5%) than female patients (3 of 70; 4.3%) (P = 0.012). Logistic regression analysis revealed that male sex, individuals with diabetes mellitus, and patients whose non-branching length of the ECA was short (16.1 ± 6.7 mm) were at high risk of ECA problems. We set the cutoff point at 17.5 mm (the area under the receiver operator characteristic curve was 0.72). CONCLUSIONS: Our findings indicate that patients, especially male patients, treated by EC-IC high-flow bypass using an RA graft are at increased risk for adverse events when the ECA length at the site of the planned anastomosis is shorter than 17.5 mm.

Upper Facial Anastomoses Between the External and Internal Carotid Vascular Territories - A 3D Computed Tomographic Investigation.

BACKGROUND: Facial regions with a high risk for causing injection-related visual comprise are dual-supply vascular areas such as the nose, glabella, and forehead. These regions have in common that they receive arterial blood supply both by branches of the internal (ICA) and the external carotid artery (ECA). OBJECTIVE: The authors sought to investigate the anastomotic pathways between ICA and ECA branches in the upper face. METHODS: Postmortem computed tomographic angiographic scans of n = 38 Chinese non-embalmed hemifaces (25 males, 13 females; mean age, 37.79 [11.8] years; mean BMI, 21.90 [2.3] kg/m2) were conducted. Data analysis relied on the calculation of depth, distances, and pathways of forehead and temporal arteries to investigate the number of anastomotic connections, the connecting branches, and the layer of connection between ICA and ECA territories. RESULTS: Between ICA and ECA territories, only 1 connection in 57.9%, 2 connections in 31.6%, 3 connections in 5.3%, and 4 and 5 connections in 2.6% each were identified. A superficial connection was observed in 15.8% whereas in 84.2% the anastomotic connection was identified to be both superficial and deep. CONCLUSIONS: Adverse events following facial minimally invasive soft-tissue filler injections for aesthetic purposes are not frequent but devastating if they occur. Anatomic knowledge as presented in this study can help to increase awareness of 3-dimensional vascular anastomotic pathways and identify safer injection zones and safer fascial planes. Evidence-based injection techniques should be followed, and safety aspects should be placed over the aesthetic outcome.