A review of the carotid artery and facial nerve canal systems in extant turtles

The cranial circulation and innervation systems of turtles have been studied for more than two centuries and extensively used to understand turtle systematics. Although a significant number of studies related to these structures exists, a broader comprehension of variation across the tree has been hindered by poor sampling and a lack of synthetic studies that addressed both systems together. We here provide new insights regarding the carotid circulation and facial nerve innervation systems in a broad set of extant turtles using CT (computed tomography) scans, which allow us to trace the canals these structures form in bone and understand the interaction between both systems. We document that the palatine artery, including the lateral carotid canal, is absent in all pleurodires and carettochelyids and was likely reduced or lost several times independently within Testudinoidea. We also highlight osteological correlates for the location of the mandibular artery. We finally summarize variation regarding the placement of the mandibular artery, location of the geniculate ganglion, placement of the hyomandibular and vidian nerves, and situations where we recommend caution when assessing canals in fossils. A morphometric study confirms that the relative sizes of the carotid canals are correlated with one another. Our results have the potential for building new phylogenetic characters and investigating the circulation systems of fossil taxa, which are expected to shed light on the evolution of the circulation system of turtles and clarify some unresolved relationships between fossil turtle clades.

First in Man Pilot Feasibility Study in Extracranial Carotid Robotic-Assisted Endovascular Intervention

BACKGROUND Robotic-assistance in endovascular intervention represents a nascent yet promising innovation. OBJECTIVE To present the first human experience utilizing robotic-assisted angiography in the extracranial carotid circulation. METHODS Between March 2019 and September 2019, patients with extracranial carotid circulation pathology presenting to Houston Methodist Hospital were enrolled. RESULTS A total of 6 patients met inclusion criteria: 5 underwent diagnostic angiography only with robotic-assisted catheter manipulation, while 1 underwent both diagnostic followed by delayed therapeutic intervention. Mean age was 51 +/− 17.5 yr. Mean anesthesia time was 158.7 +/− 37.9 min, mean fluoroscopic time was 22.0 +/− 7.3 min, and mean radiation dose was 815.0 +/− 517.0 mGy. There were no technical complications and no clinical deficits postprocedure. None of the cases required conversion to manual neurovascular intervention (NVI). CONCLUSION Incorporating robotic technology in NVI can enhance procedural technique and diminish occupational hazards. Its application in the coronary and peripheral vascular settings has established safety and efficacy, but in the neurovascular setting, this has yet to be demonstrated. This study presents the first in human feasibility experience of robotic-assisted NVI in the extracranial carotid circulation.

Protective effect of vitrectomy on the course of diabetic retinopathy: A case report

Purpose: To hypothesize the protective role of vitrectomy on the natural course of diabetic retinopathy. Methods: Case report. Results: A 66-year-old lady with a history of type 1 diabetes mellitus since the age of 10 was referred for evaluation. She received laser treatment in her left eye for proliferative diabetic retinopathy 6 years earlier, while her right eye underwent vitrectomy for retinal detachment 17 years before. Diabetic retinopathy was found to be substantially asymmetrical, as the vitrectomized right eye had only mild macular edema without significant vascular abnormalities, whereas the left eye had a complete confluent panretinal photocoagulation with advanced atrophic macular changes. Other reasons for this asymmetry, such as axial length disparity, carotid circulation impairment, or history of branch retinal vein occlusion, were not identified. Conclusions: Vitreous removal, performed for a reason other than diabetic retinopathy, may inhibit the retinal complications often associated with longstanding diabetes. Further clinical studies should be considered to ascertain such evidence.

Endovascular Treatment for Bilateral Carotid Stenosis: a Case Report

Carotid artery stenosis is usually a consequence of thromboembolism or atheroembolism, or it can be secondary to a low-velocity status in the carotid circulation. This disease can also represent an important cause of stroke, being responsible for 7% of all stroke cases. Endovascular techniques were recently proposed as alternative interventions for patients with high risk for endarterectomy. We present the case of a 70-year-old patient, accusing headache, vertigo, and fatigue. Angiography indicated bilateral carotid artery stenosis. Interventional surgery and angioplasty were performed, crossing the stenotic lesions of the left internal carotid artery, followed by the implantation of a Carotid WALLSTENT endoprosthesis. Evolution of the patient was favorable after the endovascular intervention, with significant improvement of the symptoms caused by bilateral carotid stenosis. As a conclusion, decision-making must be modulated in each patient, according to the patient’s anatomy and comorbidities, and the experience of the team performing the procedure.

Neurovascular anatomy of the protostegid turtle Rhinochelys pulchriceps and comparisons of membranous and endosseous labyrinth shape in an extant turtle

Chelonioid turtles are the only surviving group of reptiles that secondarily evolved marine lifestyles during the Mesozoic Early chelonioid evolution is documented by fossils of their stem group, such as protostegids, which yield insights into the evolution of marine adaptation. Neuroanatomical features are commonly used to infer palaeoecology owing to the functional adaptation of the senses of an organism to its environment. We investigated the neuroanatomy and carotid circulation of the early Late Cretaceous protostegid Rhinochelys pulchriceps based on micro-computed tomography data. We show that the trigeminal foramen of turtles is not homologous to that of other reptiles. The endosseous labyrinth of R. pulchriceps has thick semicircular canals and a high aspect ratio. Comparisons among turtles and other reptiles show that the endosseous labyrinth aspect ratio is not a reliable predictor of the degree of aquatic adaptation, contradicting previous hypotheses. We provide the first models of neuroanatomical soft tissues of an extant turtle. Turtle brain morphology is not reflected by the brain cavity, and the endosseous labyrinth provides an incomplete reflection of membranous semicircular duct morphology. Membranous labyrinth geometry is conserved across gnathostomes, which allows approximate reconstruction of the total membranous labyrinth morphology from the endosseous labyrinth despite their poor reflection of duct morphology.

Moyamoya Disease

Moyamoya disease is defined by stenosis of the distal intracranial internal carotid arteries up to and including the bifurcation, with segments of the proximal anterior and middle cerebral arteries, dilated basal collateral vessels, and bilateral findings. Detailed assessment with digital subtraction angiography will define the severity of disease (Suzuki stage) and presence of spontaneous transdural collateral vessels from external carotid artery branches. These collateral vessels must be protected during surgical intervention. The surgical goal is to establish a new vascular supply to the areas of the brain at risk for stroke, utilizing vessels from the external carotid circulation. Blood pressure control and avoidance of hyperventilation are key to minimize perioperative stroke risk. Preoperative hydration, ongoing use of aspirin, and good pain control will also minimize surgical complications.

Clinical features, course, and outcomes of a UK cohort of pediatric moyamoya

ObjectiveTo describe characteristics and course of a large UK cohort of children with moyamoya from multiple centers and examine prognostic predictors.MethodsRetrospective review of case notes/radiology, with use of logistic regression to explore predictors of outcome.ResultsEighty-eight children (median presentation age 5.1 years) were included. Thirty-six presented with arterial ischemic stroke (AIS) and 29 with TIA. Eighty had bilateral and 8 unilateral carotid circulation disease; 29 patients had posterior circulation involvement. Acute infarction was present in 36/176 hemispheres and chronic infarction in 86/176 hemispheres at the index presentation. Sixty-two of 82 with symptomatic presentation had at least one clinical recurrence. Fifty-five patients were treated surgically, with 37 experiencing fewer recurrences after surgery. Outcome was categorized as good using the Recovery and Recurrence Questionnaire in 39/85 patients. On multivariable analysis, presentation with TIA (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02–0.35), headache (OR 0.10, 95% CI 0.02–0.58), or no symptoms (OR 0.08, 95% CI 0.01–0.68) was less likely to predict poor outcome than AIS presentation. Posterior circulation involvement predicted poor outcome (OR 4.22, 95% CI 1.23–15.53). Surgical revascularization was not a significant predictor of outcome.ConclusionsMoyamoya is associated with multiple recurrences, progressive arteriopathy, and poor outcome in half of patients, especially with AIS presentation and posterior circulation involvement. Recurrent AIS is rare after surgery. Surgery was not a determinant of overall outcome, likely reflecting surgical case selection and presentation clinical status.

The parabasisphenoid complex in Mesozoic turtles and the evolution of the testudinate basicranium

During early development of turtles and other amniotes, the parabasisphenoid, or basisphenoid s.l., is formed by at least two centers of ossification: the endochondral basisphenoid s.s. and the dermal parasphenoid. This fusion is usually so dramatic that the two elements cannot be distinguished from each other in the adult stage. Here we describe the basicranium of two individuals of Mesozoic turtles from Europe, Plesiochelys etalloni and Pleurosternon bullockii, partly using micro-CT scans, and show that in both taxa para- and basisphenoid remain distinguishable throughout life. We also identify the extent that each of the two elements has contributed to the formation of the braincase floor. Because the structure of the parabasisphenoid determines the course of the internal carotid artery into the skull, our findings allow us to discuss the early evolution of the carotid pattern and the turtle basicranium in new detail. By surveying the main patterns of carotid circulation in extinct and extant turtles, we bring new evidence to the idea that it was largely the ossification of the parasphenoid which, along with the closure of the interpterygoid vacuity and the posterior extension of the pterygoids, shaped the internal carotid patterns as seen in modern turtles.

Treatment of Distal Anterior Circulation Aneurysms With the Pipeline Embolization Device

BACKGROUND Utilization of the Pipeline embolization device (PED) to treat distal carotid circulation aneurysms has not been well studied. OBJECTIVE: To report the collective experience of using PED to treat distal anterior circulation aneurysms. METHODS: We retrospectively reviewed clinical and radiographic records of all patients who underwent Pipeline embolization of distal anterior circulation aneurysms at 10 US neurosurgical centers between 2011 and 2013. RESULTS: Twenty-eight patients (mean age 51.7 years; 18 women) with 28 aneurysms were included in the analyses. Fifteen aneurysms were fusiform, 5 dissecting, and 8 saccular. Average aneurysm size was 12.3 mm; 7 were giant. Twenty aneurysms were located along the middle cerebral artery, 6 along the anterior cerebral artery, and 2 along the anterior communicating artery. PED deployment was successful in 27 patients, with coils utilized in 6 cases. Clinical follow-up was available for an average of 10.7 months (range 3-26). Twenty-seven patients had follow-up neurovascular imaging: 21 aneurysms had complete occlusion, 4 had residual neck filling, and 2 had residual dome filling. Periprocedural complications (<30 days) occurred in 3 patients (10.7%), including 1 case of device failure resulting in stroke. Outcomes were good (modified Rankin Scale score 0 to 2) in 27 patients (96.4%) and fair (modified Rankin Scale 3) in 1. CONCLUSION: PED can be utilized in the treatment of distal anterior circulation aneurysms with difficult anatomy for conventional surgical or endovascular techniques. Larger-scale studies with long-term follow-up are needed to further elucidate the durability of PED treatment and its effect on perforator-rich vascular segments.