Neurofibromatosis and Arterial Aneurysms.

Neurofibromatosis (NF) is a common autosomal dominant disease characterized by the development of hamartomatous or neoplastic lesions due to the proliferation of neural crest cells. An association of aneurysmal arterial lesions with NF, which may have catastrophic complications, has been rarely reported. Our recent experiences with the diagnosis and management of three male NF patients with aneurysms is described. A 19-year-old-man with refractory hypertension due to unilateral, complex, unreconstructable renal artery aneurysms was successfully treated by nephrectomy. Histopathology demonstrated intramural renal artery Schwann cell proliferation. A 44-year-old patient underwent ligation of a ruptured superior mesenteric artery aneurysm. Finally, a femoral-popliteal artery saphenous vein bypass graft with aneurysm exclusion was performed in a 58-year-old-man with a 3.5 cm symptomatic popliteal artery aneurysm. In NF, the underlying pathology in large arteries is intramuscular Schwann cell proliferation with secondary fibrosis. Mesodermal dysplasia may affect small arteries resulting in stenosis, post-stenotic dilatation, or aneurysmal degeneration. Clinicians should be aware of the unusual association of NF with aneurysms, particularly the occult development of visceral and renal artery aneurysms. These lesions are subject to sudden rupture with potentially devastating consequences, and they mandate a high index of suspicion in NF patients

Determination of Carotid Plaque Risk By Ultrasonic Tissue Characterization.

This in vitro study investigated the ability of ultrasonic tissue characterization (UTC) to discriminate between plaques from asymptomatic and symptomatic patients and to compare UTC findings with quantitative measurements of plaque morphology. A total of 34 plaque specimens removed at carotid endarterectomy were scanned transversely at intervals of 1 mm, and compared to tissue cross-sections examined by optical microscopy employing computer-assisted planimetry. UTC was performed by spectral analysis of backscattered radiofrequency signals. The slope, intercept and total power parameters of the spectrum were evaluated. Discriminant analysis was used to compare the ability of the UTC spectral parameters and morphological constituents to correctly classify plaques according to their symptom group membership. UTC correctly classified 88.2% of the plaques. Thrombus was present in 93.9% of the plaques, and there was little difference in the morphological constituents of plaques from asymptomatic and symptomatic patients. Morphological constituents correctly classified 60.7% of the plaques. We conclude, in this preliminary study, that UTC can discriminate between carotid plaques from asymptomatic and symptomatic patients with moderate accuracy, despite a similarity in their morphological composition. UTC discrimination is not related to differences in the type or amount of morphological constituents in the plaques