Case Report

Angiographic infundibular dilation: Is it worth exploring?

Pedro Nogarotto Cembraneli1
,  
Italo Nogarotto Cembraneli2
,  
Renata Brasileiro de Faria Cavalcante3
,  
Volmer Fernandes Valente Junior4
,  
José Edison da Silva Cavalcante5
,  
Rherold Santana6
,  
Julia Brasileiro de Faria Cavalcante7

1 MD, Santa Mônica Hospital, Aparecida de Goiânia, GO, Brazil

2 Medical Sciences Course, Health Sciences School, Faculdade Ceres (FACERES), São José do Rio Preto, SP, Brazil

3 MD, Neurosurgeon, Member of the Brazilian Society of Neurosurgery (SBN), Santa Monica Hospital, Aparecida de Goiânia – GO, Brazil

4 MD, Neurosurgeon, Member of the Brazilian Society of Neurosurgery (SBN), Santa Monica Hospital, Aparecida de Goiânia – GO, Brazil

5 MD, PhD in Neurosurgery, Neurosurgeon, Member of the Brazilian Society of Neurosurgery (SBN), Head of the Neurosurgery Medical Residency Service, Santa Monica Hospital, Aparecida de Goiânia – GO, Brazil

6 MD, Resident in Neurosurgery at Santa Mônica Hospital, Aparecida de Goiânia, GO, Brazil

7 MD, Santa Mônica Hospital, Aparecida de Goiânia, GO, Brazil

Address correspondence to:

Pedro Nogarotto Cembraneli

Santa Mônica Hospital, Chácara Aurora, BR-153, km 8,5 Vila Sul, Aparecida de Goiânia, GO,

Brazil

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Article ID: 101182Z01PC2020

doi: 10.5348/101182Z01PC2020CR

How to cite this article

Cembraneli PN, Cembraneli IN, Cavalcante RBF, Valente VF, Cavalcante JES, Santana R, Cavalcante JBF. Angiographic infundibular dilation: Is it worth exploring? Int J Case Rep Images 2020;11:101182Z01PC2020.

ABSTRACT

Introduction: Infundibular dilations are generally considered normal anatomical variants devoid of pathogenic significance. However, some of them change in time and show certain characteristics similar to saccular aneurysms.

Case Report: A 40-year-old male patient was hospitalized due to subarachnoid hemorrhage, resulting from the rupture of an aneurysm at the level of the anterior communicating artery. Additionally, an infundibular dilation of 6 mm in diameter was detected at the level of the right posterior communicating artery. The patient underwent an open surgery, using the pterional craniotomy approach to the right. The aneurysm of the anterior communicating artery was clipped with some difficulty because previous hemorrhage and hematoma were covering the aneurysmal neck. A mini clip was used to laterally decrease the infundibular dilation. Upon releasing the clip, we evidenced not an infundibulum, but a typical aneurysm, with the posterior communicating artery well attached to its wall, which was released and exposed at the time of clipping.

Conclusion: Infundibular dilation is a potential source of bleeding, but it rarely ruptures and is little valued by radiologists and neurosurgeons. The care inherent in the discovery of an infundibular aneurysm, even if it is insidious, must be the same as that applied to classical types of aneurysm. Moreover, the therapeutic approach should be chosen when the infundibular aneurysm is equal to or greater than 4 mm in diameter.

Keywords: Aneurysm, Angiographic findings, Angiography, Infundibular dilation

Introduction

The posterior communicating arteries originate from the cerebral part of the internal carotid arteries on both sides, mainly due to the posterolateral or posterior aspect, and after a course of approximately 12 mm it joins the posterior cerebral artery in the interpeduncular cistern [1],[2],[3]. The posterior communicating arteries may present conical, triangular, or funnel-shaped infundibular dilations, which are considered normal anatomical variants devoid of pathogenic significance. Nonetheless, some of them change in time and show certain characteristics that are similar to saccular aneurysms [3],[4].

Although they rarely rupture, infundibular dilations are a potential source of bleeding, and therefore are little valued by radiologists and neurosurgeons. Radiological control is usually disregarded even by the patients. Consequently, they are often only diagnosed in the presence of subarachnoid hemorrhage, when they rupture [5],[6],[7].

Case Report

A 40-year-old male patient, with no previous diseases, was hospitalized due to subarachnoid hemorrhage, resulting from the rupture of an aneurysm at the level of the anterior communicating artery, diagnosed through conventional cerebral angiography, by catheterization (Figure 1). In addition to this aneurysm, an infundibular dilation of 6 mm in diameter was detected at the level of the right posterior communicating artery (Figure 2 and Figure 3). The radiologist suggested that it was a simple infundibular dilation, and the main focus of the radiological interpretation was to assess the characteristics of the anterior communicating artery aneurysm that had caused the subarachnoid hemorrhage.

Our team decided for an open surgery, using the pterional craniotomy approach to the right. The aneurysm of the anterior communicating artery was clipped with some difficulty, since previous hemorrhage and hematoma were covering the aneurysmal neck.

Immediately after, we explored the referred infundibular dilation. At first, the image observed in the microscope was really very typical of a dilation in the emergence of the posterior communicating artery, triangle-shaped and with an enlarged base, as it can be seen in the angiography (Figure 4).

We chose to use a mini clip to laterally decrease the infundibular dilation. Upon releasing the clip, we evidenced not an infundibulum, but a typical aneurysm, with the posterior communicating artery well attached to its wall, which was released and exposed at the time of this clipping (Figure 5).

Figure 1: Saccular aneurysm of the anterior communicating artery.
Figure 2: Infundibular dilation at the level of the posterior communicating artery.
Figure 3: Typical conical infundibular dilation.
Figure 4: Surgical aspect of infundibular dilation (blue arrow) and posterior communicating artery (green arrow).
Figure 5: Individualization of the posterior communicating artery and clipped aneurysm.

Discussion

The reported incidence of infundibular dilation of the posterior communicating artery detected by angiography varies from 6% to 17% and increases with age. The dilation is approximately triangle-shaped and its diameter does not exceed 3 mm [8],[9].

The exact and natural history of infundibular dilation is still controversial [6],[10]. Radiological images not always clarify the real shape of this dilation, or reveal hidden or adherent vessels on its surface, hence the difficulty of indicating surgery without a precise diagnosis [8],[11],[12].

The differential diagnosis between an infundibular dilation and a small aneurysm is not always easy, even with conventional service techniques. Given that dilations are considered benign, the most sophisticated radiological techniques are not used. Sometimes, the structure of the service does not allow the purchase of more sophisticated devices [6],[7],[12].

Conclusion

The care inherent in the discovery of an infundibular aneurysm, even if it is insidious, must be the same as that applied to classical types of aneurysm. Systematic follow-ups with imaging exams (angiography, magnetic resonance imaging, tomography) should be performed. Moreover, the therapeutic approach should be chosen when the infundibular aneurysm is equal to or greater than 4 mm in diameter.

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González-Darder JM, Feliu R, Pesudo JV, et al. Surgical management of posterior communicating artery aneurysms based on computed tomographic angiography with three-dimensional reconstruction and without preoperative angiography. [Article in Spanish]. Neurocirugia (Astur) 2003;14(3):207–15. [CrossRef] [Pubmed] Back to citation no. 1  

SUPPORTING INFORMATION

Author Contributions

Pedro Nogarotto Cembraneli - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Italo Nogarotto Cembraneli - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Renata Brasileiro de Faria Cavalcante - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Volmer Fernandes Valente Junior - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

José Edison da Silva Cavalcante - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Rherold Santana - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Julia Brasileiro de Faria Cavalcante - Substantial contributions to conception and design, Acquisition of data, Analysis of data, Interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Data Availability Statement

The corresponding author is the guarantor of submission.

Consent For Publication

Written informed consent was obtained from the patient for publication of this article.

Data Availability

All relevant data are within the paper and its Supporting Information files.

Competing Interests

Authors declare no conflict of interest.

Copyright

© 2020 Pedro Nogarotto Cembraneli et al. This article is distributed under the terms of Creative Commons Attribution License which permits unrestricted use, distribution and reproduction in any medium provided the original author(s) and original publisher are properly credited. Please see the copyright policy on the journal website for more information.