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INTRODUCTION: Numerical classification systems for the internal carotid artery (ICA) are available, but modifications have added confusion to the numerical systems. Furthermore, previous classifications may not be applicable uniformly to microsurgical and endoscopic procedures. The purpose of this study was to develop a clinically useful classification system. MATERIALS AND METHODS: We performed cadaver dissections of the ICA in 5 heads (10 sides) and evaluated 648 internal carotid arteries with computed tomography angiography. We identified specific anatomic landmarks to define the beginning and end of each ICA segment. RESULTS: The ICA was classified into eight segments based on the cadaver and imaging findings: (1) Cervical segment; (2) cochlear segment (ascending segment of the ICA in the temporal bone) (relation of the start of this segment to the base of the styloid process: Above, 425 sides [80%]; below, 2 sides [0.4%]; at same level, 107 sides [20%]; P < 0.0001) (relation of cochlea to ICA: Posterior, 501 sides [85%]; posteromedial, 84 sides [14%]; P < 0.0001); (3) petrous segment (horizontal segment of ICA in the temporal bone) starting at the crossing of the eustachian tube superolateral to the ICA turn in all 10 samples; (4) Gasserian-Clival segment (ascending segment of ICA in the cavernous sinus) starting at the petrolingual ligament (PLL) (relation to vidian canal on imaging: At same level, 360 sides [63%]; below, 154 sides [27%]; above, 53 sides [9%]; P < 0.0001); in this segment, the ICA projected medially toward the clivus in 275 sides (52%) or parallel to the clivus with no deviation in 256 sides (48%; P < 0.0001); (5) sellar segment (medial loop of ICA in the cavernous sinus) starting at the takeoff of the meningeal hypophyseal trunk (ICA was medial into the sella in 271 cases [46%], lateral without touching the sella in 127 cases [23%], and abutting the sella in 182 cases [31%]; P < 0.0001); (6) sphenoid segment (lateral loop of ICA within the cavernous sinus) starting at the crossing of the fourth cranial nerve on the lateral aspect of the cavernous ICA and located directly lateral to the sphenoid sinus; (7) ring segment (ICA between the 2 dural rings) starting at the crossing of the third cranial nerve on the lateral aspect of the ICA; (8) cisternal segment starting at the distal dural ring. CONCLUSIONS: The classification may be applied uniformly to all skull base surgical approaches including lateral microsurgical and ventral endoscopic approaches, obviating the need for 2 separate classification systems. The classification allows extrapolation of relevant clinical information because each named segment may indicate potential surgical risk to specific structures.
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BACKGROUND AND STUDY AIMS: High prevalence rates of coeliac disease (CD) in patients with type 1 diabetes mellitus (T1DM) have been reported. The aim of this study was to evaluate the frequency of silent CD in a sample of Iraqi patients with T1DM. PATIENTS AND METHODS: This is a cross-sectional study done in Baghdad Teaching Hospital, Baghdad Medical City, Baghdad, Iraq, on 62 patients with T1DM. For all patients, immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (IgA tTG), IgG anti-tissue transglutaminase antibodies (IgG tTG), IgA endomysial antibody (IgA EMA), IgA antigliadin antibodies (IgA AGA) and IgG antigliadin antibodies (IgG AGA) tests were done, with duodenoscopy, and at least four biopsies were taken from the second part of the duodenum. RESULTS: A total of 27 patients (43.5%) had normal small-intestinal histopathology (Marsh 0), one of them had a positive result for all serological markers used in the study, and another patient was positive for IgA tTG only. Ten patients (16.1%) had Marsh grade I, one of them was positive for IgA tTG, IgG tTG and IgA EMA, another patient was IgA deficient and had positive IgG tTG only and another patient with Marsh I had positive IgA tTG and IgG tTG only. Two patients (3.2%) had Marsh IIIA; three patients (4.8%) had Marsh IIIB histopathology, two of them were positive for all tests and one had positive IgA tTG and IgA EMA only. Two patients (3.2%) had Marsh IIIC histopathological features; they were positive for all serological tests, hence, the frequency of CD was 11.2%. CONCLUSION: The frequency of silent CD in Iraqi patients with T1DM is not rare, reaching up to 11.2%. Both EMA and tTG antibodies are useful as screening tests.
