Kinking, coiling, and tortuosity of extracranial internal carotid artery: is it the effect of a metaplasia?

INTRODUCTION: Morphological anomalies of the extracranial internal carotid artery (ICA) cause symptomatic cerebrovascular insufficiency in 4-16% of the cases. The aim of the present study is to evaluate macroscopic and microscopic features of a group of extracranial ICA anomalies, specifically kinking, coiling, and tortuosity, eventually affecting the surgical approach. MATERIALS AND METHODS: From January 2003 to December 2005, 10 out of 169 (6%) revascularized patients (pts) were operated upon because of an ICA anomaly. They were all but two symptomatics. Seven pts were treated by ICA transection and end-to-side reimplantation of the ICA at the level of the carotid bulb; three pts were treated by ICA resection and end-to-end anastomosis. In all the cases a segment of ICA was resected; in three cases one more segment was also obtained from a common carotid artery (CCA) and these specimens were histologically examined. Patients were followed-up through a 3-year period. RESULTS: No pts died and none suffered of neurologic events. Duplex scan and arteriographic postoperative control showed the correct surgical reconstruction. Matching preoperative clinical findings with presence or absence of significant atherosclerotic stenotic lesion, we found out a positive cerebral CT in one pt (20%) in both groups; fluent neurological deficit was preeminent in pts with pure ICA anomalies (40% vs. 0%) (P = 0.2); pts with pure ICA anomalies were significantly younger than 65 years old (80% vs. 0%) (P = 0.03) and males were more involved by pure ICA anomalies (60% vs. 40%) (P = 0.1). The histological examination of ICA specimens showed a reduction of elastic fibers and muscular cells with a compensative increase of connective fibers. CONCLUSIONS: At our knowledge this is the first study focused on ICA anomalies like kinking, coiling, and tortuosity, comparing histologic features of CCA and ICA specimens coming from the same affected carotid axis. Our results, although preliminary, show elastic and muscular tissue substituted by loose connective tissue, configuring a metaplasia of tunica media limited to the ICA. Our hypothesis is that extracranial ICA, being a segment of transition between an elastic vessel (CCA) and a muscular vessel (intracranial ICA), is particularly subject to metaplastic transformation, analogously to other transition zones in human body. Our purpose is now to confirm by ultrastructural and molecular biology techniques, in a wider series, the presence of this metaplasia, since this could condition also the revascularization techniques.

Localization of the atrial natriuretic factor in the human inferior turbinates. An immunohistochemical study.

In man, the architecture of the turbinates is able to modify some of the physiochemical characteristics of the air inhaled. These modifications depend on the nervous system and on the action of neurotransmitters such as vasoactive intestinal peptide. Substance P, calcitonin gene-related peptide and other neuropeptides. As atrial natriuretic factor has been detected in the trachea and lung, the present immunohistochemical study was carried out to establish the presence and localisation of the atrial natriuretic factor on the inferior turbinates of the human being. The findings show atrial natriuretic factor to be present in the serous epithelial cells and in some cells of the tonaca propria near the sinusoids and the arteriovenous shunts and the acinar cells of the glands. Atrial natriuretic factor, therefore, could play a part in the stratification of mucus on the luminal surface and also regulate the blood flow of the capillaries, modifying, in this way, the physiochemical features of the air inhaled.

Presence of atrial natriuretic factor in normal and hyperplastic human prostate and its relationship with oxytocin localisation.

In this work, we showed the presence of atrial natriuretic factor (ANF) in human prostate and compared its localisation in normal and hyperplastic conditions. ANF was localised in epithelial and stromal cells, being increased in hyperplasia, mainly in the stromal component. Moreover, we compared ANF and oxytocin positivity in the same glands, focusing on the possible relationship between the paracrine effects of these two hormones.