An angiographic study of incidence and morphology of infundibular dilatation of the posterior communicating artery

Abstract

In the last 9 years, infundibular dilatation (ID) has been sought in 260 aneurysm (An) cases and 398 carotid angiogram's (CAG) to reveal its incidence and morphology. Findings were as follows: The incidence was about double that so far published. Small ID, usually triangular in shape, tended to become round as it grew larger (P less than 0.01). Large ID favored young age (P less than 0.05). In internal carotid-posterior communicating aneurysm (IC-P com An) cases, a high incidence of ID was noted as compared to other An cases (P less than 0.05), and intermediate or large, round ID accounted for high ratios. Cases with a history of hypertension showed a high large ID ratio (P less than 0.05). Cases with well developed P com A had a high ratio of large, round ID (P less than 0.01). In cases with a large divergent angle of ICA and P com A, intermediate or large, round ID was found in high ratio (P less than 0.05). Aggressive follow-up or treatment was thought necessary in cases which possess the factors mentioned.

Successful Treatment of a Ruptured Enlarged Infundibular Widening of the Posterior Communicating Artery. Case Report.

“…Therefore, a long period of follow up is necessary for patients with infundibular widening. More careful observation should be performed, especially in cases of infundibular widening 4) associated with a contralateral ICA-PcomA aneurysm, in young patients, in hypertensive patients, with well-developed PcomA, with a great divergent angle with respect to the ICA, or associated with a small bulge of the wall as in the present case.…”

“…1,7,16) The occurrence and growth of infundibular widening seems to be influenced by the balance between the local tissue fragility of the infundibular wall and the hemodynamic stress. 4) Analysis of the intraoperative and angiographic findings of 34 lesions at the ICA-PcomA junction identified preoperatively as unruptured aneurysms because of a diameter exceeding 3 mm, non-visualized PcomA, or PcomA not originating at the apex of the widening found that six of the lesions were true aneurysms, four were enlarged infundibular widenings with reddish bulges (i.e., preaneurysmal bulge), and 24 were merely enlarged infundibular widenings without wall abnormality. 5) The diagnosis of cerebral aneurysm should not be based simply on the size and shape of the dilatation, especially if the PcomA does not fill or appears very small on carotid angiography.…”

“…14) The incidence of infundibular widening is about 5-17% on carotid angiography, and increases with age. 4,8,12,15) Infundibular widening usually does not rupture, but has caused fatal subarachnoid hemorrhage (SAH) 1,12) and development of cerebral aneurysm. 3,10,11,17,18) Here, we describe the successful treatment of a case of ruptured enlarged infundibular widening.…”

Manejo y tratamiento microquirúrgico de las dilataciones infundibulares de la arteria comunicante posterior: Serie de nueve casos y revisión de la literatura

“…También se han considerado factores hemodinámicos relacionados con el efecto 'jet´1 4 . Ebina et al 6 estudiaron las características angiográficas de las DI y encontraron que una AComP bien desarrollada podría ser uno de los factores que puedan contribuir al desarrollo aneurismático a partir de una DI, en especial si ésta es grande o se asocia a un gran ángulo divergente entre la AComP y la ACI. La revisión de la bibliografía sugiere que existe una alta incidencia de buen llenado de la AComP en aneurismas desarrollados a partir de una DI.…”

“…El tiempo medio de progresión es de unos 7 años (rango, 0,5-11 años), aunque el tiempo de progresión viene determinado por la fecha de realización de la prueba de imagen y esto hace que los datos no representen con exactitud la realidad. Ebina et al 6 en un interesante trabajo elaboraron una serie de conclusiones con implicaciones pronósticas: que las pequeñas DI tienden a crecer, y en su crecimiento pasan de una forma triangular a una forma redondeada; que las DI más grandes aparecen en pacientes jóvenes; que hay un mayor número de casos de DI en pacientes que tienen un aneurisma de la AComP contralateral; que la HTA, al igual que tener una AComP bien desarrollada, son factores predisponentes para tener una gran DI y de forma redondeada además en el segundo caso; que aumenta la posibilidad de tener una DI de tamaño intermedio o grande a mayor ángulo de divergencia formado entre la ACI y la AComP; y, finalmente, los autores proponían para todos estos casos un exhaustivo control y/o tratamiento agresivo.…”