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Concept: External carotid artery


There are considerable variations in the anatomy of the human ophthalmic artery (OphA), such as anomalous origins of the OphA and anastomoses between the OphA and the adjacent arteries. These anatomical variations seem to attribute to complex embryology of the OphA. In human embryos and fetuses, primitive dorsal and ventral ophthalmic arteries (PDOphA and PVOphA) form the ocular branches, and the supraorbital division of the stapedial artery forms the orbital branches of the OphA, and then numerous anastomoses between the internal carotid artery (ICA) and the external carotid artery (ECA) systems emerge in connection with the OphA. These developmental processes can produce anatomical variations of the OphA, and we should notice these variations for neurosurgical and neurointerventional procedures.

Concepts: Embryo, Developmental biology, Internal carotid artery, Common carotid artery, External carotid artery, Embryology, Arteries of the head and neck, Ophthalmic artery


Embozene® is a new neuroembolizing microsphere used to reduce intraoperative bleeding for head and neck tumours. We report a case of iatrogenic ophthalmic artery occlusion after Embozene® embolization of the external carotid artery (ECA).

Concepts: Head and neck anatomy, Head and neck, Internal carotid artery, Common carotid artery, External carotid artery, Arteries of the head and neck, Ophthalmic artery


Objectives: A growing body of evidence indicates that primary snoring (PS) may be the initial presentation of sleep-disordered breathing and can adversely affect an individual’s health. Individuals with the sole diagnosis of PS were evaluated to determine if a relationship exists between snoring and thickening of the intima media of the carotid arteries. Study Design: Cross sectional study. Methods: Our institution’s sleep center database identified patients aged 18 to 50 years who had a diagnostic sleep study with apnea-hypopnea index <5 between December 2006 and January 2012. Subjects underwent a diagnostic carotid artery duplex ultrasound measuring the intima-media thickness (IMT) of the bilateral carotid arteries at four separate points. A validated snoring outcomes survey (SOS) was completed and used to categorize "snorers" and "non-snorers." Groups were compared using a student's t-test. Results: Of 913 patients who met inclusion criteria, 54 patients completed both the carotid duplex ultrasound and SOS. There were no statistically significant differences in IMT for the groups defined by smoking or diabetes. Compared to non-snorers, snorers were found to have a significantly greater IMT at two points along the left internal carotid artery and one point on the right side. When considering all 8 points, IMT was significantly greater in snorers. Conclusion: This study shows a relationship between PS and IMT of the carotid arteries. Given the well-described relationship between increased carotid IMT and serious health conditions, non-apneic snoring may be a precursor to changes of the carotid artery intima and should be further investigated.

Concepts: Internal carotid artery, Common carotid artery, External carotid artery, Intima-media thickness


The anterior clinoid process (ACP) is critically related to the clinoidal portion of the internal carotid artery (ICA). The deep location of the ACP makes treatment of vascular and neoplastic lesions related to the ACP challenging. Removal of the ACP is advocated to facilitate treatment of such lesions. However injury to the clinoidal ICA remains a potential and dreadful complication of ACP removal. The aim of this study was to demonstrate an endoscopic assisted technique to perform intradural removal of the ACP via a pterional approach with continuous visualization of the clinoidal ICA.

Concepts: Internal carotid artery, Common carotid artery, External carotid artery, Carotid sinus, Internal jugular vein, Anterior clinoid process


Transient monocular blindness and amaurosis fugax are umbrella terms describing a range of patterns of transient monocular visual field loss (TMVL). The incidence rises from ≈1.5/100,000 in the third decade of life to ≈32/100,000 in the seventh decade of life. We review the vascular supply of the retina that provides an anatomical basis for the types of TMVL and discuss the importance of collaterals between the external and internal carotid artery territories and related blood flow phenomena. Next, we address the semiology of TMVL, focusing on onset, pattern, trigger factors, duration, recovery, frequency-associated features such as headaches, and on tests that help with the important differential between embolic and non-embolic etiologies.

Concepts: Internal carotid artery, Common carotid artery, External carotid artery, Blindness, Visual field, Amaurosis fugax


: In transarterial embolization of anterior cranial fossa and tentorial dural arteriovenous fistula (DAVF), acute angulation of the feeding artery off the internal carotid artery (ICA) may render stable distal catheterization and, therefore, successful transarterial treatment difficult. In some anatomic dispositions, following selection of the feeding artery, subsequent forward force may lead to prolapse of the microcatheter into the ICA rather than advancing it into either the ophthalmic artery or the meningohypophyseal trunk.

Concepts: Internal carotid artery, Common carotid artery, External carotid artery, Internal jugular vein, Arteriovenous fistula, Fistula, Arteries of the head and neck, Ophthalmic artery


We report the case of a 40-year-old woman with a severe factor XI (FXI) deficiency who died from a stroke due to bilateral internal carotid arteries occlusion after a laparoscopic gastric bypass (bariatric surgery). This stroke was probably secondary to a pulmonary embolism with a paradoxical embolism through a previously unknown foramen ovale. This woman who had one severe episode of bleeding before the bypass received for the intervention a single infusion of 27 U/kg of FXI concentrate. A careful evaluation of the bleeding and thrombotic risk was performed before surgery, and despite all preventive measures, this tragic event occurred. The aim of this report is to alert medical teams to carefully balance the benefit-risk of such an intervention in a patient with a severe FXI deficiency.

Concepts: Obesity, Internal carotid artery, Common carotid artery, External carotid artery, Carotid sinus, Internal jugular vein, Factor XI, Embolism


: During evaluation for monocular visual loss, a 48-year-old woman was found to have a posttraumatic paraophthalmic internal carotid artery (ICA) pseudoaneurysm. She underwent reconstruction of the ophthalmic segment of the right ICA with a Pipeline embolization device but her vision did not return.

Concepts: Internal carotid artery, Common carotid artery, External carotid artery, Ophthalmology, Carotid sinus, Internal jugular vein, Ophthalmic artery, Amaurosis fugax


BACKGROUND: Endovascular treatment of intracranial aneurysms relies on coaxial catheter support systems to provide safe and stable access. Large-bore distal intracranial catheters have become necessary for aneurysm treatment with flow diverting devices including the Pipeline embolization device (PED). These catheters must accommodate 0.027 inch microcatheters, be supple enough to track distally and be able to provide sufficient support for manipulations required for PED deployment. METHODS: A single-center aneurysm database was reviewed to identify patients who underwent anterior circulation aneurysm embolization with the PED while using the Navien distal intracranial catheter. Data were collected regarding the equipment used, cervical internal carotid artery (ICA) tortuosity, intraprocedural Navien positions and periprocedural complications. RESULTS: The Navien catheter (5 Fr, 0.070 inch outer diameter, 0.058 inch inner diameter, 115 cm) was used in 78 cases of anterior circulation PED. It was tracked into position over a Marksman microcatheter in 76 of the 78 cases (97%). The final catheter tip position was in the cervical ICA (1/78, 1%), petrous ICA (23/78, 30%), proximal cavernous ICA (48/78, 62%), distal cavernous/clinoidal ICA (3/78, 4%), supraclinoid ICA (2/78, 2%) and the M1 segment (1/78, 2%). In each case the catheter was tracked to its desired position (100% clinical success) despite significant proximal vessel tortuosity in 34 cases (44%). No clinically significant catheter-related complications occurred. CONCLUSIONS: The Navien intracranial catheter is an important component of the triaxial system for embolization of cerebral aneurysms with the PED. This catheter is highly trackable to distal positions, atraumatic and provides sufficient support for the microcatheter manipulations used during typical PED deployments.

Concepts: Internal carotid artery, Common carotid artery, Posterior communicating artery, External carotid artery, Aneurysm, Cerebral aneurysm, Catheter, Cavernous sinus


All previously documented regional anesthesia procedures for carotid artery surgery routinely require additional local infiltration or systemic supplementation with opioids to achieve satisfactory analgesia because of the complex innervation of the surgical site. Here, we report a reliable ultrasound-guided anesthesia method for carotid artery surgery. High-resolution ultrasound-guided regional anesthesia using a 12.5-MHz linear ultrasound transducer was performed in 34 patients undergoing carotid endarterectomy. Anesthesia consisted of perivascular regional anesthesia of the internal carotid artery and intermediate cervical plexus block. The internal carotid artery and the nerves of the superficial cervical plexus were identified, and a needle was placed dorsal to the internal carotid artery and directed cranially to the carotid bifurcation under ultrasound visualization. After careful aspiration, local anesthetic was spread around the internal carotid artery and the carotid bifurcation. In the second step, local anesthetic was injected below the sternocleidomastoid muscle along the previously identified nerves of the intermediate cervical plexus. The necessity for intra-operative supplementation and the conversion rate to general anesthesia were recorded. Ultrasonic visualization of the region of interest was possible in all cases. Needle direction was successful in all cases. Three to five milliliters of 0.5% ropivacaine produced satisfactory spread around the carotid bifurcation. For intermediate cervical plexus block, 10 to 20 mL of 0.5% ropivacaine produced sufficient intra-operative analgesia. Conversion to general anesthesia because of an incomplete block was not necessary. Five cases required additional local infiltration with 1% prilocaine (2-6 mL) by the surgeon. Visualization with high-resolution ultrasound yields safe and accurate performance of the block. Because of the low rate of intra-operative supplementation, we conclude that the described ultrasound-guided perivascular anesthesia technique is effective for carotid artery surgery.

Concepts: Anesthesia, Local anesthesia, Internal carotid artery, Common carotid artery, External carotid artery, Internal jugular vein, Local anesthetic, Cervical plexus