Lung underdevelopment is a rare congenital anomaly with variable clinical significance and presenting symptoms. It usually manifests during childhood. We present two cases of developmental lung anomaly subtypes and discuss clinical presentation and outcomes in such patient populations.
CONCLUSIONS: Pulmonary underdevelopment is a challenging diagnosis and should be considered in patients with unilateral opacification on chest radiograph.Childhood developmental history is critical for diagnosis as delayed, or misdiagnoses are common. Definitive diagnosis can be made by computed tomography scan.Management is watchful waiting with close monitoring, with long term prognosis remaining unclear.

(1) Background. The anatomical variations of the vertebral arteries (VAs) have a significant impact both in neurosurgery and forensic pathology. The purpose of this study was to evaluate the variational anatomy of the vertebral artery. We evaluated anatomical aspects regarding the V1 and V2 segments of the VA: origin, course, tortuosity, hypoplasia, and dominance, and established the prevalence of each variation. (2) Methods. We conducted a systematic search in PubMed and Google Scholar databases, up to December 2022. Sixty-two studies, comprising 32,153 vessels, were included in the current meta-analysis. We used a random-effects model with a DerSimonian-Laird estimator. The confidence intervals were set at 95%. The heterogeneity between studies was assessed using I2. The funnel plot and Egger\'s regression test for plot asymmetry were used for the evaluation of publication bias. Statistical significance was considered at p < 0.05. (3) Results. The most common site for the origin of both VAs was the subclavian artery. The aortic arch origin of the left VA had a prevalence of 4.81%. Other origins of the right VAs were noted: aortic arch (0.1%), right common carotid artery (0.1%), and brachiocephalic trunk (0.5%). Ninety-two percent of the VAs entered the transverse foramen (TF) of the C6 vertebra, followed by C5, C7, C4, and least frequently, C3 (0.1%). Roughly one out of four (25.9%) VAs presented a sort of tortuosity, the transversal one representing the most common variant. Hypoplasia occurred in 7.94% of the vessels. Left VA dominance (36.1%) is more common, compared to right VA dominance (25.3%). (4) Conclusions. The anatomy of the VA is highly irregular, and eventual intraoperative complications may be life-threatening. The prevalence of VA origin from the subclavian artery is 94.1%, 92.0% of the VAs entered the TF at C6, 26.6% were tortuous, and 7.94% were hypoplastic.

Renal artery stenosis (RAS) accounts for approximately 5%-10% of secondary renovascular hypertension in the pediatric population. It can occur as an isolated entity, or as a hypoplasia combined itself with stenosis. Hypoplasia, or long-segment developmental narrowing, is a rare cause of renovascular hypertension. Hyponatremic hypertensive syndrome (HHS) is a malignant complication of unilateral RAS and/or renal artery hypoplasia. Hyponatremia, hypokalemic hypochloremic metabolic alkalosis, nephrotic range proteinuria, polyuria, polydipsia, and weight loss are the most common findings. In particular, hypertension remains refractory despite aggressive antihypertensive therapy. Laboratory findings of elevated plasma levels of renin in most case suggest that the stimulation of renin release from the ischemic kidney plays an important pathophysiologic role. HHS is a diagnostic and therapeutic challenge in children. We report a case of a unilateral right renal artery hypoplasia, complicated by a segmental narrowing, in a 17-month-old male, clinically symptomatic for hypertension. We emphasize the role of ultrasound, computed tomography, and digital subtraction angiography that should be planned as reliable and non-invasive multimodal imaging approach.

Uniformly narrowed internal carotid artery (ICA) without proximal steno-occlusion or parietal anomalies is often subject to misdiagnosis due to lack of awareness. We combined our experiences of 4 cases with 29 previously published cases to form a retrospective series including 18 cases of ICA hypoplasia and 15 cases of ICA acquired narrowing. The ultrasonic manifestations of ICA acquired narrowing and ICA hypoplasia are extremely similar, but narrowed ICA without intracranial occlusion or bottle-neck-sign highly indicates ICA hypoplasia, whereas moyamoya vessels favor ICA acquired narrowing, thus promoting the understanding of and discriminability between the two on neurovascular ultrasound.

This review evaluates the current evidence for the clinical management of congenital internal carotid artery hypoplasia (CICAH). We summarise clinical presentations diagnostic standards, imaging recommendations, treatment and follow-up. The review was prompted by a case of CICAH in a 50-year-old female who presented to our neurosurgery clinic with an acute episode of vertigo. The patient underwent CT angiogram, which showed an unusually low right carotid bifurcation. The right internal carotid artery (ICA) was hypoplastic, and the A1 segment of the anterior cerebral artery (ACA) was absent. Skull base CT showed an ipsilateral hypoplastic carotid canal. To summarise current evidence for clinical management of CICAH we followed PRISMA guidelines to identify papers meeting our predefined inclusion criteria. We searched three databases using the terms \'ICA\' and \'Hypoplasia\'. We reviewed 41 papers meeting our criteria. 34 were clinical reports. We performed a data extraction and quality appraisal on these reports. We found that CICAH may be less rare than previously described. Blood pressure control in CICAH is crucial due to the increased risk of stroke and aneurysm formation. Follow-up imaging is strongly recommended. Carotid doppler sonography is a powerful and underutilised diagnostic tool, and carotid canal hypoplasia is not a pathognomic sign. In conclusion, clinicians should be alert to anatomic variations such as CICAH because these produce haemodynamic changes that may have serious clinical consequences. We recommend a central registry of patients with CICAH in order to understand the longer-term natural history of the condition.

BACKGROUND: Central retinal artery occlusion (CRAO) is an emergent ophthalmic disease which is commonly caused by atherosclerosis, thromboembolism, and arteriospasm. Here, we report a case of CRAO which is caused by extreme rare bilateral internal carotid artery (ICA) hypoplasia complicated with patent foramen ovale (PFO). The cardiogenic emboli blocked central retinal artery through unclosed foramen ovale and specific blood flow pathway.
METHODS: This report describes a case of a 46-year-old woman sudden onset with amaurosis fugax for about 20 min and persistent visual impairment of left eye. Fundus fluorescein angiography shows the arm-retinal circulation time of left eye is 25 s, indicating that the occlusion occurs in the pathway from aortic arch to ophthalmic artery. The MRA and CTA examinations reveal the bilateral ICA hypoplasia and variation of Wills circle. Furthermore, transesophageal echocardiography (TEE) confirms the PFO and cardiogenic embolic event.
CONCLUSIONS: This work presents a CRAO case caused by rare congenital hypoplasia of ICA complicated with PFO, reminding us every single cause of vascular disease should be investigated carefully and the TOAST typing of cerebrovascular disease can be of great reference to the ocular vascular disease.

UNASSIGNED: Isolated symptomatic cervical stenosis of the atlas is quite rare; there have been 11 cases reported in literature.
UNASSIGNED: A 76-year-old male presented with myelopathy attributed to C1 arch stenosis. Neuroimaging studies revealed posterior atlas compression of the spinal cord. Following a cervical laminectomy involving excision of the arch of the atlas, and the patient\'s symptoms resolved.
UNASSIGNED: C1 stenosis resulting in cervical myelopathy due to posterior compression from the arch of the atlas is easily missed. Notably, C1 arch laminectomy may be very effective in resolving this entity.

Hemifacial microsomia (HFM) is the 2nd most common craniofacial birth defect after cleft lip and palate. It is said to arise from the 1st & 2nd intrauterine branchial arches. HFM is believed by many experts to be congenital but not inherited as most patients afflicted have no previous family history. It also known as craniofacial microstomia with cranial involvement. The real cause is unknown but largely blamed on hemorrhage of the stapaedial artery. The phenotypic expression is variable from mild to severe involving many structures such as bone, nerve, muscular tissues and soft tissue. Facial structures commonly affected include the ears, the mouth and the mandible. Mostly unilateral but bilateral have been reported. However, not much is known about this condition in sub-Saharan Africa. Multidisciplinary team management is the general consensus for optimal care. Awareness in sub-Saharan Africa of this disorder is still evolving. This review identifies various classifications, diagnoses, investigations, treatment and timelines for management of HFM. The aim of the current review was to discuss the diverse controversies, classification, diagnosis and treatment of HFM so as to increase the understanding of this condition.

UNASSIGNED: Absence or hypoplasia of the internal carotid artery (ICA) is a rare congenital anomaly that is mostly unilateral and highly associated with other intracranial vascular anomalies, of which saccular aneurysm is the most common. Blood flow to the circulation of the affected side is maintained by collateral pathways, some of which include the anterior communicating artery (Acom) as part of their anatomy. Therefore, temporary clipping during microsurgery on Acom aneurysms in patients with unilateral ICA anomalies could jeopardize these collaterals and place the patient at risk of ischemic damage. In this paper, we review the literature on cases with a unilaterally absent ICA associated with Acom aneurysms and provide an illustrative case.
UNASSIGNED: We combined our experience of one case of a unilaterally absent ICA associated with an Acom aneurysm with the 33 existing publications on the same subject in the literature, for a total of 40 cases. We provide a detailed systematic literature review of this association of vascular anomalies, exploring different aspects regarding the collateral pathways and how they impact management strategies and propose a management algorithm to deal with such association.
UNASSIGNED: The mean age was 48.2 ± 16.5 years. The aneurysmal rupture was the most common presentation (75%). Agenesis was observed in 70% of patients, followed by hypoplasia (20%) and, finally, aplasia (10%). Lie Type A was the most common pattern of collaterals (50%), with Types B and D being of almost equal proportions. Most aneurysms were located at the A1-Acom junction contralateral to the anomalous side (Fisher\'s Exact test; P = 0.03). One case of temporary clipping was reported in the literature.
UNASSIGNED: Acom aneurysms in patients with unilateral ICA anomalies, given they are more commonly present contralaterally, could be of acquired etiology, warranting periodic screening in asymptomatic patients. Temporary clipping might be safe in patients with Type D collateral pattern, while those with Types A or B may require intraoperative rupture risk assessment and a tailored management plan to avoid disrupting collateral flow and causing ischemia.

OBJECTIVE: Congenital anomaly of the internal carotid artery (ICA) is a rare entity. It is usually discovered incidentally by color doppler carotid sonography, angiography, computerized tomography (CT), or magnetic resonance imaging of the head and neck region taken for some other reasons. The aim of this study was to detect congenital ICA anomalies, to delineate existing collateral vessels and to find out its incidence.
METHODS: 1847 patients\' CT angiography images of the head and neck region taken between May 2013 and February 2018 were retrospectively evaluated for ICA anomalies.
RESULTS: We detected three cases (0.16%) with unilateral agenesis of ICA, bilateral agenesis of ICA and bilateral hypoplasia of ICA, respectively. Most patients are asymptomatic because of collateral cerebral circulation supplied by the communicating arteries of the circle of Willis, intercavernous anastomosis, communicating arteries from the external carotid artery, and by persistent embryologic arteries to the carotid artery territory.
CONCLUSIONS: Recognition of ICA anomalies has important implications during planned carotid or transsphenoidal surgery, in thromboembolic disease, and in the follow-up and detection of associated cerebral aneurysms.