A scarce combination of arterial variants: an occipital artery originating from the internal carotid artery associated with a linguofacial trunk.

The occipital artery (OA) typically originates from the external carotid artery (ECA). Variations of the ECA has been well described in the current literature, while the OA is a relatively stable vessel, and its variations are uncommon. In the current case report, an aberrant OA has been found coexisting with a linguofacial trunk (LFT) on the right hemineck of a 51-year-old male patient. The OA was identified originating from the cervical internal carotid artery (ICA) at the level of the second cervical vertebra (C2). On the ECA, the lingual and facial arteries were emanating in common, as LFT. The left hemineck of the patient was free of variations. The current coexistence of arterial variants has been reported only once previously; therefore, the current case corresponds to the second case in the English literature. The aberrant OA origin from the ICA has been estimated with a pooled prevalence of 0.37%, while the origin at the C2 level and from the anterior surface of the ICA corresponds to a very rare variation. Additionally, the LFT is one of the most common trunk that can be found on the ECA. Interventional radiologists and surgeons must be aware of common and uncommon variation to avoid iatrogenic lesion.

The superior thyroid artery origin pattern: a systematic review with meta-analysis.

PURPOSE: The current systematic review with meta-analysis aimed to investigate the pooled prevalence of the superior thyroid artery (STA) pattern of origin (distinct or fused-common origin with adjacent arteries in the form of a common trunk). The standard and uncommon variants were also studied, considering the STA's exact surface of origin and the relationship with the upper border of the thyroid cartilage (TC, reference point), considering the laterality effect. Thus, the STA topographical anatomy was considered. METHODS: An evidence-based systematic review with meta-analysis was performed according to the PRISMA 2020 guidelines. A literature search was conducted in four online databases using specific keywords, the pooled prevalence was calculated using statistical analysis in the R programming language, and multiple subgroup analyses were performed. RESULTS: The most common distinct origin of the STA was from the external carotid artery (ECA) (56.94% pooled prevalence, 95%CI: 50.89-62.89), and the rarest one was from the internal carotid artery (ICA) (< 0.01%, 95%CI: 0.00-0.00). Common trunks were also investigated, with the thyrolingual trunk emanating from the ECA estimated at 0.61% (95%CI: 0.21-1.14), representing the most common. Subgroup analysis based on the nationality, type of study, and sample size, as well as a comparison between left and right sides and males and females, were investigated. CONCLUSIONS: The most common STA origin was estimated as the ECA, the medial surface of origin, and above the TC upper border. Adequate knowledge of STA origin is paramount for surgeons, especially during thyroidectomy, not to cause iatrogenic injury to the external branch of the superior laryngeal nerve.

Outcome of CAS under flow reversal and analysis for the intraprocedural flow of internal carotid artery.

OBJECTIVE: Carotid artery stenting (CAS) under flow reversal with dual protection using a proximal balloon and distal filter has been an established procedure for internal carotid artery (ICA) stenosis. This study investigates the effect of external carotid artery (ECA) occlusion on outcomes of CAS and ICA flow under flow reversal. METHODS: We reviewed 231 cases of CAS under flow reversal with ECA occlusion and 32 without. In the last 14 of 32 cases, the flow in the ICA under flow reversal was analyzed by ultrasound. The collateral index, which was defined as the total value of the maximum diameters of the ipsilateral anterior cerebral artery at the A1 segment and the anterior communicating artery, as well as those of the ipsilateral posterior cerebral artery at the P1 segment and the ipsilateral posterior communicating artery, and the maximum diameter of the ipsilateral ECA were correlated with the flow direction in the ICA. RESULTS: There was no significant difference in the outcome of CAS between the groups with or without ECA occlusion. Among the 14 cases without ECA occlusion, antegrade flow in the ICA was observed in 6 cases (42.9 %). The group with the antegrade flow in the ICA exhibited a significantly lower collateral index (5.08±0.33 vs 6.71±0.28, p=0.01) and a significantly larger ECA diameter (4.66±0.51 mm vs 3.21±1.24 mm, p=0.01) than the group with the stagnant or retrograde flow in the ICA. CONCLUSIONS: The outcomes of CAS under flow reversal were acceptable even without ECA occlusion. The ECA occlusion may not be necessary for CAS under dual protection; however, distal filter protection should be used even under flow reversal.

[External Carotid Artery:Essential Knowledge of the External Carotid Artery Required for Neuroendovascular Surgery, with a Focus on the Middle Meningeal Artery and Occipital Artery].

The perfusion territory of the external carotid artery is often underestimated; however, this blood vessel forms abundant "dangerous anastomoses" with the internal carotid and vertebral arteries. An understanding of these vascular anastomoses is crucial to ensure safe cerebrovascular interventions. There are several important aspects of the middle meningeal artery that should be considered, including anastomoses with the anterior(frontal)branch and ophthalmic artery through the sphenoidal artery(recurrent meningeal artery)and meningolacrimal artery. Additionally, the blood supply to the facial nerve via branches of the petrosal branch, such as the superior tympanic artery, and the formation of the facial arcade by the superior tympanic and stylomastoid arteries, which often originate from the posterior auricular artery, is significant. The occipital artery demonstrates rich anastomoses with vessels, such as the ascending pharyngeal and vertebral arteries, forming what is known as the pharyngo-occipital system.

[The Ascending Pharyngeal Artery, Accessory Meningeal Artery, Lingual Artery, Vasa Nervorum, and Potential Anastomotic Channels].

The ascending pharyngeal, accessory meningeal, and lingual arteries branch from the proximal segment of the external carotid artery. These branches give rise to smaller branches that contribute blood supply to the pharyngeal mucosa, parapharyngeal tissue, middle ear, submandibular tissues, tongue, and dura mater of the middle and posterior fossa. These arteries may also supply the cranial nerves and have potential anastomotic channels that function with the internal carotid and vertebral arteries. M igration of embolic material into the vasa nervorum and potential anastomoses may cause complications. Therefore, knowledge of these functional anatomies is crucial for neuro-interventionalists.

Facilitating Repeat Intracarotid Injections in Mouse Models by a Novel Injection Site Repair Technique.

Given recent advances in the delivery of novel antitumor therapeutics using endovascular selective intraarterial delivery methods in neuro-oncology, there is an urgent need to develop methods for intracarotid injections in mouse models, including methods to repair the carotid artery in mice after injection to allow for subsequent injections. We developed a method of intracarotid injection in a mouse model to deliver therapeutics into the internal carotid artery (ICA) with two alternative procedures. During injection, the needle is inserted into the common carotid artery (CCA) after tying a suture around the external carotid artery (ECA) and injected therapeutics are delivered into the ICA. Following injection, the common carotid artery (CCA) can be ligated, which limits the number of intracarotid injections to one. The alternative procedure described in this article includes a modification where intracarotid artery injection is followed by injection site repair of the CCA, which restores blood flow within the CCA and avoids the complication of cerebral ischemia seen in some mouse models. We also compared the delivery of bone marrow-derived human mesenchymal stem cells (BM-hMSCs) to intracranial tumors when delivered through intracarotid injection with and without injection site repair following the injection. Delivery of BM-hMSCs does not differ significantly between the methods. Our results demonstrate that injection site repair of the CCA allows for repeat injections through the same artery and does not impair the delivery and distribution of injected material, thus providing a model with greater flexibility that more closely emulates intracarotid injection in humans.

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.

Case of giant juvenile angiofibroma resected by external incision with temporary double balloon occlusion of the internal carotid artery by intraoperative endovascular treatment.

We report the first case of a juvenile nasal angiofibroma (JNA) fed by multiple arteries from the internal carotid artery (ICA), removed without complications by temporarily blocking the ICA with two balloons. An early adolescent with JNA underwent preoperative embolisation of feeding arteries arising from the external carotid artery (ECA) (University of Pittsburgh Medical Centre classification IV). Endoscopic resection was attempted once but discontinued due to massive bleeding (7000 mL). 17 months later, the JNA had grown to fill both nasal cavities. Repeated preoperative embolisation of the feeders from the ECA was performed, followed by surgery combined with endoscopic and external incision. Intraoperatively, two balloons were inserted into the right ICA, which were inflated at the proximal and distal sites of the feeder vessels to cut-off blood flow to the tumour. The tumour was almost completely resected with 6270 mL of blood loss and no postoperative neurological deterioration.

The use of Microsurgical Exploration of the External Carotid Artery for Removal of a Retained Microcatheter After Middle Meningeal Artery Embolization Using Live Fluoroscopy: A Technical Note.

BACKGROUND: Fragmentation, disconnection, or entrapment of an in-use microcatheter during neuro-endovascular procedures is a known risk. Often a benign entity, retained catheters are not infrequently observed, but severe complications including thrombus, thromboembolic events, pseudoaneurysm, and limb ischemia have been described, necessitating retrieval. This technical case report demonstrates the safe use of an external carotid artery (ECA) approach for ligation and removal of a retained microcatheter after middle meningeal artery (MMA) embolization. This article also demonstrates the use of live intraoperative fluoroscopy as a surgical adjunct to ensure that the catheter is fully removed without any injury, shearing, or breakage during removal. METHODS: A 66-year-old male patient presented with bilateral subdural hematomas to an outside hospital. He subsequently underwent evacuation of the hematomas followed by a right-sided MMA embolization, complicated by Onyx (Medtronic, Minneapolis, MN) entrapment of the microcatheter in the MMA. The patient was asymptomatic, but there was significant concern about continuing antiplatelet/anticoagulation therapy in the presence of the subdural hematoma. We proceeded with an open surgical approach for catheter retrieval. As the catheter was withdrawn, intraoperative fluoroscopy demonstrated complete removal without any retained fragments. RESULTS: The patient recovered without event and was discharged on postoperative day 1. On follow-up the patient continued to do well without any complications from the fragment that remained in the external carotid circulation. CONCLUSIONS: This case and accompanying video demonstrates the effective use of open ECA surgical approach to retrieve the retained microcatheter after an MMA embolization. This approach allowed for safe and effective removal of the microcatheter while significantly reducing complication risks.

The Diversity of the Linguofacial Trunk.

Background and Objectives: Typically, the external carotid artery (ECA) sends off separate anterior branches: the superior thyroid, lingual, and facial arteries. These could, however, form common trunks: thyrolinguofacial, linguofacial (LFT), or thyrolingual. Although known, the LFT variant was poorly detailed previously, and most authors just counted the variant. We aimed to demonstrate the individual anatomical possibilities of the LFT on a case-by-case basis. Materials and Methods: 150 archived angioCT files were used. After applying inclusion and exclusion criteria, 147 files of 86 males and 61 females were kept for this study. Results: In 34/147 cases, LFTs were found (23.12%). Bilateral LFTs were found in 13/34 cases (38.24%) and unilateral LFTs in 21/34 (61.76%) cases. Forty-seven LFTs were thus identified and further studied for different variables. Regarding the vertical topography of LFT origin, type 1a (suprahyoid and infragonial) was found in 28 LFTs (59.57%), type 1b (suprahyoid and gonial) was found in eight LFTs (17.02%), type 3 (suprahyoid and supragonial) was found in two LFTs (4.25%), type 2 (hyoid level of origin) in eight LFTs (17.02%), and type 3 (infrahyoid origin) in just one LFT (2.12%). Types of the initial course of the LFT were determined: type I, ascending, was found in 22/47 LFTs; type II, descending, in 12/47 LFTs; and type III, transverse, in 13/47 LFTs. Regarding the orientation of the first loop of the LFT, 23/47 LFTs had no loop, 4/47 had anterior loops, 1/47 had a posterior loop, 5/47 had superior loops, 5/47 had inferior loops, and 9/47 had medial loops. The position of the LFT relative to the ECA was classified as medial, anterior, or antero-medial. An amount of 12/47 LFTs were anterior to the ECA, 22/47 were antero-medial, 10/47 were medial, 2/47 were inferior, and 1/47 was lateral. Regarding their general morphology, 23/47 LFTs had a rectilinear course, 22/47 had loops, and 2/47 were coiled. A case-by-case presentation of results further demonstrated the diversity of the LFT. Conclusions: In conclusion, the morphology and topography of the LFT are individually specific and unpredictable. It can be anticipated case-by-case by surgeons on CT or MR angiograms.

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.

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.

Short-term and long-term effects of unilateral external carotid artery ligation on orofacial functions in rats.

The external carotid artery (ECA) plays a major role in supplying blood to the head and neck. Although impeded blood flow in the ECA is expected to affect orofacial functions, few studies have shown how blood flow obstruction in the ECA contributes to impairment of these functions, including chewing and swallowing. This study was performed to investigate the effects of ECA ligation (ECAL) on immediate and long-term changes in masticatory and swallowing functions as well as the jaw-opening reflex evoked in the digastric muscle. The experiments were carried out using male Sprague-Dawley rats. In the acute experiment, the digastric reflex evoked by low-threshold electrical stimulation of the inferior alveolar nerve and the swallow reflex, identified by digastric and thyrohyoid electromyographic (EMG) bursts, were compared between before and 1 h after ECAL. The chronic experiment was conducted on freely moving rats. EMGs of the masseter, digastric, and thyrohyoid muscles were chronically recorded. The long-term effects of ECAL on behavior and muscle histology were compared between rats with an intact ECA and rats with ECAL. In the acute experiment, the peak amplitude of the digastric reflex on the ECAL side was significantly decreased 1 h after ECAL. In the chronic experiment, although most parameters of the masticatory and swallowing EMGs were not significantly different between the groups, the results suggest wide variation of the effect of ECAL on the muscles. Blood supply compensation from collaterals of the internal carotid artery may be permanent in some animals.NEW & NOTEWORTHY The inhibitory effect of unilateral external carotid artery ligation (ECAL) on the ipsilateral digastric reflex was small but evident. Most parameters of masticatory and swallowing muscle activity were not significantly different after ECAL. Wide variation was noted in the effect of ECAL on the ipsilateral muscle activity. Blood supply compensation from collaterals of the internal carotid artery may occur in response to the impaired blood flow.

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.

"Dual Internal Shunts Technique" for Carotid Endarterectomy with Carotid Vertebral Anastomosis: Technical Note.

In revascularization of internal carotid stenosis with carotid vertebrobasilar anastomoses, attention should be paid not only to the anterior circulation but also to the posterior circulation cerebral infarction. A 74-year-old man was referred for treatment of carotid artery stenosis; NASCET 75% stenosis in the right internal carotid artery and acute cerebral infarction were confirmed. Occlusion of the left subclavian artery and vascular anastomosis between the right external carotid artery and the vertebral artery were indicated, such that the right external carotid artery may maintain blood flow to the vertebrobasilar artery. Therefore, dual shunts were used for the common and internal carotid arteries and the common and external carotid arteries to maintain blood flow during carotid endarterectomy. Management of the dual shunts is difficult due to the instable parallel placement of the common carotid artery shunt balloons. To solve this problem, the "dual internal shunts technique" was performed. The first shunt was inserted into the external and common carotid arteries, and the second into the internal and common carotid arteries. The shunt balloon on the common carotid artery side was placed distal to the first shunt balloon so that the dual balloons were placed in a tandem position. The proximal balloon was subsequently deflated gradually to improve flow in both shunts. The procedure is technically easy and safe.

Transient Middle Cerebral Artery Occlusion Model of Stroke.

Stroke stands as a major cause of death or chronic disability globally. Nevertheless, existing optimal treatments are limited to reperfusion therapies during the acute phase of ischemic stroke. To gain insights into stroke physiopathology and develop innovative therapeutic approaches, in vivo rodent models of stroke play a fundamental role. The availability of genetically modified animals has particularly propelled the use of mice as experimental stroke models. In stroke patients, occlusion of the middle cerebral artery (MCA) is a common occurrence. Consequently, the most prevalent experimental model involves intraluminal occlusion of the MCA, a minimally invasive technique that doesn't require craniectomy. This procedure involves inserting a monofilament through the external carotid artery (ECA) and advancing it through the internal carotid artery (ICA) until it reaches the branching point of the MCA. After a 45 min arterial occlusion, the monofilament is removed to allow reperfusion. Throughout the process, cerebral blood flow is monitored to confirm the reduction during occlusion and subsequent recovery upon reperfusion. Neurological and tissue outcomes are evaluated using behavioral tests and magnetic resonance imaging (MRI) studies.

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.

External carotid artery-radial artery graft-posterior cerebral artery bypass for complex vertebrobasilar aneurysms: efficacy and analysis of outcome in a single center.

The purpose of this research was to demonstrate the effectiveness and clinical outcome of an external carotid artery-radial artery graft-posterior cerebral artery (ECA-RAG-PCA) bypass in the treatment of complex vertebrobasilar artery aneurysms (VBANs) in a single-center retrospective study. An ECA-RAG-PCA bypass may be a last and very important option in the treatment of complex VBANs when conventional surgical clipping or endovascular interventions fail to achieve the desired outcome. This study retrospectively analyzed the clinical presentation, case characteristics, aneurysm location, size and morphology, choice of surgical strategy, complications, clinical follow-up, and prognosis of the patients enrolled. The data involved were analyzed by the appropriate statistical methods. A total of 24 patients with complex VBANs who met the criteria were included in this study. Eighteen (75.0%) were male and the mean age was 54.1 ± 8.83 years. The aneurysms were located in the vertebral artery, the basilar artery, and in the vertebrobasilar artery with simultaneous involvement. All patients underwent ECA-RAG-PCA bypass surgery via an extended middle cranial fossa approach, with 8 (33.3%) undergoing ECA-RAG-PCA bypass only, 3 (12.5%) undergoing ECA-RAG-PCA bypass combined with aneurysm partial trapping, and 12 (50.0%) undergoing ECA-RAG-PCA bypass combined with proximal occlusion of the parent artery. The average clinical follow-up was 22.0 ± 13.35 months. The patency rate of the high-flow bypass was 100%. At the final follow-up, 15 (62.5%) patients had complete occlusion of the aneurysm, 7 (29.2%) patients had subtotal occlusion of the aneurysm, and 2 (8.3%) patients had stable aneurysms. The rate of complete and subtotal occlusion of the aneurysm at the final follow-up was 91.7%. The clinical prognosis was good in 21 (87.5%) patients and no procedure-related deaths occurred. Analysis of the good and poor prognosis groups revealed a statistically significant difference in aneurysm size (P = 0.034, t-test). Combining the results of this study and the clinical experience of our center, we propose a surgical algorithm and strategy for the treatment of complex VBANs.The technical approach of ECA-RAG-PCA bypass for complex VBANs remains important, even in an era of rapid advances in endovascular intervention. When conventional surgical clipping or endovascular intervention has failed, an ECA-RAG-PCA bypass plays a role that cannot be abandoned and is a very important treatment option of last resort.

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.