Relation of the incidence of congenital variations and anomalies with intracranial aneurysms in intracranial arteries

Abstract

Objectives: There exists many embryological steps during the development of intracranial vascular structures. Therefore, the congenital variations and anomalies of these structures are often encountered. For a proper evaluation of cerebrovascular imaging studies it is essential to know the frequencies of these anomalies and variations, their locations and the possible accompanying patologies should be distinguished. We aimed to analyse the frequency of congenital variations and anomalies and their association with intracranial aneurysms by evaluating the cerebral angiographic images.
Methods: The cerebral angiograms taken for various reasons in the Radiology Department, Faculty of Medicine, Gaziosmanpasa University, between January 2007 and April 2009, were evaluated in a retrospective fashion. We investigated the association of intracranial aneurysms and congenital variations in addition to the influence of variations on aneurysm formation. A total of 254
cases with intracranial artery variation-anomaly and coexisting intracranial artery aneurysm were included in the study.
Results: The most common variation in intracranial arteries was the agenesis or hypoplasia of the A1 segment of anterior cerebral artery. This was followed infundibular dilatation of posterior communicating artery and fetal type posterior cerebral artery. The incidence of aneurysm was 22.5% in patients who had A1 hypoplasia-agenesia and 18.2% in patients who had trifurcation of middle cerebral artery.
Conclusion: Flow haemodynamics take an important part in the formation of intracranial saccular aneurysms. The incidence of aneurysm formation increases in congenital anomalies of intracranial vascular structures. It is necessary to explore the relationship between variations and aneurysms in order to understand the haemodynamic factors which take place in the pathogenesis of aneurysms. These ratios lead us to think that the incidence of aneurysms increases in cases which have variations when compared to those which have not. 

Keywords

• congenital variation
• intracranial aneurysm
• angiography

İntrakranyal arterlerde konjenital varyasyon ve anomalilerin sıklığı ve intrakranyal anevrizmalar ile birlikteliği

Abstract

Amaç: İntrakranyal vasküler yapıların gelişiminde pek çok embriyolojik basamak bulunur ve konjenital varyasyonları ve anomalileri sık görülür. Serebrovasküler görüntüleme çalışmalarının doğru yorumlanması için bu anomali ve varyasyonların görülme sıklıklarının, lokalizasyonlarının ve eşlik edebilecek patolojilerin ayırdedilebilmesi gereklidir. Çalışmamızda; 2004-2009 yılları arasında yapılmış olan serebral anjiogramları retrospektif olarak değerlendirerek konjenital varyasyon ve anomalilerin sıklığını ve intrakranyal anevrizmalar ile birlikteliğini araştırmayı hedefledik.
Yöntemler: Ocak 2007 ile Nisan 2009 tarihleri arasında Gaziosmanpaşa Üniversitesi Tıp Fakültesi Radyodiagnostik Anabilim Dalı’nda, çeşitli nedenlerle serebral anjiografisi yapılmış olguların arşiv görüntüleri iki radyolog tarafından, birlikte retrospektif olarak incelenmiştir. Toplam 254 olguda intrakraniyal arter varyasyon-anomalileri ve eşlik eden intrakranyal arter anevrizmaları saptanmıştır.
Bulgular: İntrakranyal arterlerde en sık görülen varyasyonlar anterior serebral arter A1 segmentinin hipoplazisi-agenezisi idi. Bunu posterior komünikan arterde infundibülar dilatasyon ve fetal orijinli posterior serebral arter izledi. A1 hipoplazisiagenezisi izlenen olgularda anevrizma görülme oranı %22,5, orta serebral arterde trifürkasyon varyasyonu olan olgularda anevrizma görülme oranı %18,2 idi.
Sonuç: Akım hemodinamiği, intrakranyal sakküler anevrizmaların oluşumunda önemli etkilere sahiptir. İntrakranyal vasküler yapıların konjenital anomalilerinde hemodinamik strese bağlı anevrizma gelişim insidansı artmaktadır. Anevrizmaların patogenezinde yer alan hemodinamik faktörler hakkında bilgi sahibi olmak için varyasyonlar ve anevrizmaların yeri arasındaki ilişkiyi incelemek gerekir. Olgu sayımız sınırlı olmakla birlikte bu oranlar, varyasyonu olmayan hastalar ile karşılaştırıldığında varyasyonlu olgularda anevrizma görülme sıklığının arttığını düşündürmektedir.

Keywords

• konjenital varyasyon
• intrakranial anevrizma
• anjiografi

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