Classification of congenital arterial and venous vascular malformations

Multidisciplinary treatment of extremity arteriovenous malformations

Congenital vascular malformations (CVMs) are a complex group of lesions that arise by embryologic dysmorphogenesis without increased endothelial proliferation that leads to structural and functional anomalies of the vascular system characterized by a wide range of presenting symptoms and often unpredictable clinical course. A recent advancement in the diagnostic and treatment modalities has resulted in a better understanding of the pathophysiology and natural history of CVMs and improved management of these lesions. The multidisciplinary approach and diagnostic algorithm used to distinguish high-flow (HFVM) from low-flow vascular malformations (LFVM) have been validated as clinically applicable for making an accurate anatomic and hemodynamic diagnosis of CVMs; they serve as a basis for proper treatment selection and significantly facilitate communication among different medical specialists. Dynamic contrast-enhanced magnetic resonance imaging is able to definitively distinguish HFVM from LFVM with accuracy of approximately 84%. In inconclusive cases, confirmatory angiography is required. Symptomatic, diffuse, extensive, macrocystic LFVMs and LFVMs that involve multiple tissue planes and vital structures are best treated with foam sclerotherapy. Primary surgical resection is the treatment of choice for localized, septated, and microcystic LFVMs. The management of HFVMs is characterized by multimodal treatment including preoperative embolization followed by complete surgical resection or sclerotherapy of the remaining venous component. Treatment of extensive CVMs is palliative and goal oriented. Implementation of the proposed diagnostic protocols and therapeutic algorithms in a multidisciplinary setting results in favorable outcomes with acceptable complication rates in this challenging patient population.

Aneurysmal dilatation of the inferior vena cava

AIM

Inferior vena cava aneurysms (IVCA) are rare, unlike aortic aneurysms. The diagnosis and treatment is challenging. This study defines clinical and echocardiographic findings in a prospective cohort of sixteen patients with fusiform IVCA.

METHODS AND RESULTS

All patients referred to the Mayo Clinic between January 2006 and July 2009 for a clinically indicated echocardiogram (36,128 patients) were screened for a dilated IVC. Sixteen cases of fusiform IVCA were identified. Eleven cases (68.8%) were female. Mean age at presentation was 76 years (range 51-89). Eleven (68.8%) had structural heart disease: with right ventricular (RV) dysfunction in 45.5% (n = 5), moderate or greater tricuspid regurgitation (TR) was seen in 36.4% (n = 4) and RV enlargement was seen in 18.2% (n = 2). The most common clinical indication for echocardiography was dyspnea (25%; n = 4) and heart failure (18.8%; n = 3). The mean IVCA diameter was 4.1 cm (range 3.8-5 cm) and the mean length of the aneurysms was 6.2 cm (range 3.5-8.7 cm), with mean right ventricular systolic pressure of 55 mmHg (range 31-105 mmHg). Five (31.3%) had at least a moderate reduction in right ventricular ejection fraction and five (31.3%) had significant TR. Among these five patients with significant TR, severe TR was present in 80%; (n = 4) and moderate to severe TR was present in 20%; (n = 1).

CONCLUSIONS

IVC aneurysms are more common in the elderly, and is associated with an increase in right sided heart pressures, significant TR, and RV dysfunction.

MRI characteristics and classification of peripheral vascular malformations and tumors

Vascular malformations and tumors comprise a broad spectrum of lesions that can cause significant morbidity and even mortality in children and adults. Classification of vascular malformations into high flow and low flow has significant impact on management since the main treatment of the former is transarterial embolization and the later percutaneous sclerotherapy. Magnetic resonance imaging (MRI) is a noninvasive effective tool for imaging and classification of vascular malformations based on the presence of lobulated masses, signal voids, and hemodynamic flow characteristics. MRI also provides details about anatomic extent of the lesion, proximity to vital structures, and involvement of multiple tissue planes. The prototype of vascular tumors is infantile hemangioma with its typical involution after a proliferative phase during infancy. Hemangioma appears as a distinct intensely enhancing soft tissue mass with enlarged feeding arteries and draining veins. Less common vascular tumors include congenital hemangioma, kaposiform hemangioendothilioma, angiolipoma, angiosarcoma, and hemangiopericytoma.

Congenital familial vascular anomalies: a study of patients with an anomalous inferior vena cava, and of their first-degree relatives

With magnetic resonance angiography and computed tomography, congenital anomalies of the inferior vena cava are diagnosed more frequently than they used to be. Accessory renal arteries identified by magnetic resonance angiography in a patient with an anomalous inferior vena cava indicated a combination of arterial and venous abnormalities. The study was initiated to screen consecutive patients with an anomalous inferior vena cava for concomitant abdominal and pelvic arterial abnormalities, and their first-degree relatives for congenital vascular anomalies. Magnetic resonance angiography identified in 2 of 5 patients with an anomalous inferior vena cava concomitant accessory renal arteries and in 5 of 11 first-degree relatives major abdominal vascular anomalies including accessory renal arteries, accessory renal veins, and anomalies of the hepatic artery. None of the relatives showed abnormalities of the inferior vena cava. The familial occurrence of vascular anomalies strongly suggests an underlying pathogenetic component in affected family members. In patients with a congenital anomaly of the inferior vena cava, concomitant arterial abnormalities should be considered. First-degree relatives may be at risk for congenital vascular anomalies.

Absent Relative Afferent Pupillary Defect in an Asymptomatic Case of Lateral Chiasmal Syndrome from Cerebral Aneurysm

INTRODUCTION

This report documents a case of an asymptomatic 34-year-old female who had right eye subtle temporal optic nerve pallor with absent clinically detectable relative afferent pupillary defect.

CASE REPORT

This presentation was secondary to a fusiform paraclinoid aneurysm resulting in lateral chiasmal syndrome. Visual fields demonstrated a nasal depression OD. Neuroimaging studies revealed the presence of a fusiform paraclinoid aneurysm compressing the right optic nerve and optic chiasm. The lesion was treated surgically without additional visual loss nor systemic and neurological complications.

CONCLUSIONS

A clinically detectable relative afferent pupillary defect may be absent in unilateral optic nerve pallor and/or visual field loss and does not preclude the need to attempt to identify an underlying etiology. Neuroradiological examination of orbital and cranial structures is an imperative protocol in the appropriate management of this potential life- and vision-threatening condition.