Microsurgical clipping for the true posterior communicating artery aneurysm in the distal portion of the posterior communicating artery

Fusiform "True" Posterior Communicating Artery Aneurysm with Basilar Artery Occlusion: A Case Report

Isolated posterior communicating artery (PCoA) aneurysms are rare, predominantly fusiform in morphology, and rarely present with subarachnoid hemorrhage. Endovascular management of this pathology is technically challenging due to extreme tortuosity, the artery course in the subarachnoid space, sharp angulations at PCoA junctions with the parent artery, and, at times, associations with either internal carotid artery or basilar artery occlusions. We present a case of a ruptured fusiform PCoA at the junction of middle and distal third with concomitant proximal basilar artery occlusion. The PCoA reforms the posterior circulation, making it a vital artery. Stent-assisted coiling was performed with extreme difficulty in achieving distal positioning of the stents in the basilar artery/posterior cerebral artery/distal PCoA due to artery tortuosity. There was technical difficulty in the stent deployment. After changing strategies to a larger diameter laser-cut stent, endovascular treatment could be performed. There were good angiographic and clinical outcomes with stable occlusion at 6-month-follow-up.

Morphometric analysis of oculomotor triangle in dry human skulls and its clinical applications

The oculomotor triangle is denoted as the "Triangle of Hakuba" or the "Hakuba's Triangle." This oculomotor triangle is a significant anatomical landmark. Oculomotor nerve, abducens nerve and part of the internal carotid artery (ICA) lie in this triangle. The determination of this analysis is to calculate the oculomotor triangle in dry processed skull bones of the south Indian population and its clinical significance. Fifty-one processed skulls of human origin were received from Anatomy Department, Basic Medical Sciences, Saveetha Dental College. Length from anterior-clinoid process (ACP) to posterior-clinoid process (PCP), length from PCP to APEX, and length from ACP to APEX were measured. Paired samples t-test was considered to analyze the values between the right triangle with the left triangle. From the measurements taken, the mean for the left side of the oculomotor triangle, ACP to PCP was 8.0591 ± 0.52 mm and the right side was 7.5482 ± 0.52 mm. The mean left side of the oculomotor triangle, measured from PCP to APEX was 6.73 ± 0.48 mm and the right side was 6.55 ± 0.72 mm. The mean of the left side of the oculomotor triangle, measured from ACP to APEX was 15.94 ± 0.682 mm and the right side was 16.21 ± 0.747 mm. Through this paired triangle of the cranial cavity, the horizontal section of ICA may be correlated with numerous vascular-related pathological considerations.

Microsurgical Approach for True Posterior Communicating Artery Aneurysms: Literature Review and Illustrative Case

True posterior communicating artery (PCoA) aneurysms are rare. Although true PCoA aneurysms have been reported to be located close to the internal carotid artery, at the middle part of PCoA, or close to the posterior cerebral artery; the best surgical approach to treat true PCoA aneurysms in each location remains unclear. We conducted a literature review using data from PubMed. Data on demographics, location, and projecting direction of the aneurysm, surgical approach, and surgical complications were collected. A total of 47 true PCoA aneurysms were included. Twenty-nine aneurysms originated from the proximal portion, 10 from the middle portion, and 6 from the distal portion; there were two giant aneurysms. The ipsilateral pterional approach was used for 37 true PCoA aneurysms (27 in proximal portion, 8 in middle portion, and 2 in distal portion of PCoA). The anterior temporal approach was used for two distal-portion aneurysms and one giant aneurysm. The anterior subtemporal approach was used for one distal-portion aneurysm. The subtemporal approach was used for two middle-portion aneurysms and one giant aneurysm. The contralateral pterional approach was used for two proximal-portion and one distal-portion aneurysms. Although most true PCoA aneurysms can be treated by the pterional approach, other means such as anterior temporal and subtemporal approaches can be applicable for aneurysms in the middle and distal portions of the PCoA or giant aneurysms. Surgeons should select an appropriate approach for each aneurysm while considering the advantages and disadvantages of each technique.

True Posterior Communicating Artery Aneurysms with High Risk of Rupture despite Very Small Diameter

Objective

This retrospective study investigated the clinical and angiographic characteristics of ruptured true posterior communicating artery (PCoA) aneurysms in comparison with junctional PCoA aneurysms presenting with a subarachnoid hemorrhage.

Methods

The medical records and radiological data of 93 consecutive patients who underwent three-dimensional rotational angiography and surgical or endovascular treatment for a ruptured junctional or true PCoA aneurysm over an 8-year period were examined.

Results

The maximum diameter of the ruptured true PCoA aneurysm (n=13, 14.0%) was significantly smaller than that of the ruptured junctional PCoA aneurysms (n=80, 4.45±1.44 vs. 7.68±3.36 mm, p=0.001). In particular, the incidence of very small aneurysms <4 mm was 46.2% (six of 13 patients) in the ruptured true PCoA aneurysm group, yet only 2.5% (two of 80 patients) in the ruptured junctional PCoA aneurysm group. Meanwhile, the diameter of the PCoA was significantly larger in the true PCoA aneurysm group than that in the junctional PCoA aneurysm group (1.90±0.57 vs. 1.15±0.49 mm, p<0.001). In addition, the ipsilateral PCoA/P1 ratio was significantly larger in the true PCoA aneurysm group than that in the group of a junctional PCoA aneurysm (mean PCoA/P1 ratio±standard deviation, 2.67±1.22 vs. 1.14±0.88; p<0.001). No between-group difference was identified for the modified Fisher grade, clinical grade at admission, and 3-month modified Rankin Scale score.

Conclusion

A true PCoA aneurysm was found to be associated with a larger PCoA and ruptured at a smaller diameter than a junctional PCoA aneurysm. In particular, the incidence of a ruptured aneurysm with a very small diameter <4 mm was significantly higher among the patients with a true PCoA aneurysm.

Traumatic Subarachnoid Hemorrhage Resulting from Posterior Communicating Artery Rupture

Traumatic subarachnoid hemorrhage (SAH), a common finding following head trauma, is usually a benign condition with a favorable outcome, seldom requiring surgical intervention. Unlike nontraumatic aneurysmal SAH, most cases of traumatic SAH occur in the sulci of the cerebral convexities, and only rarely arise at the base of the brain. Basal traumatic SAH can be life-threatening and is primarily associated with rupture of vertebrobasilar arteries. We herein present a rare case of basal traumatic SAH resulting from rupture of the posterior communicating artery (PCoA). A 77-year-old male was taken to the emergency department in a semicomatose state. Upon arrival at emergency room, the patient had a Glasgow coma scale (GCS) score of 6 (E1M3V2), and the neurologic examination demonstrated no focal neurologic deficit. Although the trauma history was evident from abrasions and bruising on the face and chest, brain computed tomography (CT) demonstrated basal SAH, which is typical for nontraumatic aneurysmal SAH. Subsequent digital subtraction angiography (DSA) disclosed a traumatic rupture at the mid-portion of right PCoA and ongoing extravasation of contrast media. Despite emergent trapping of the right PCoA by endovascular surgery, the patient’s clinical condition only minimally improved. The patient remained bed-ridden with stuporous mentality and persistent hydrocephalus. To the best of our knowledge, this is the first reported case of basal traumatic SAH originating from rupture of the PCoA. This case demonstrates that a meticulous vascular workup is mandatory for every patient with basal SAH, even though a trauma history is clear.

Treatment of true posterior communicating artery aneurysms: Endovascular experience in a single center

BACKGROUND AND OBJECTIVE

The true posterior communicating artery (TPCoA) aneurysms are rare and endovascular treatment for such lesions is limited in literature.

METHODS

From January 2012 to March 2017, eight TPCoA aneurysms were treated endovascularly and included in our present study. The procedural complication and outcomes were assessed.

RESULTS

Seven of eight aneurysms (87.5%) were ruptured. Stent-assisted coiling was used in one case that a stent was deployed via PCoA-ipsilateral P2 segment. The dual-microcatheter technique was used in one case. The remaining six cases were treated by coiling alone. One patient (12.5%) suffered perioperative complication, of which a coil herniated into parent vessel during the procedure without symptomatic stroke or other adverse event after the procedure. The initial embolization results showed complete occlusion in five cases and residual neck in three. Six patients (75%) had a mean of 15-month angiographic follow-up and two of them revealed recurrence (33.3%). Clinical follow-up was available in seven patients (87.5%) and all patients showed favorable clinical outcome with mRS score 0.

CONCLUSION

TPCoA aneurysms are rare and challenging lesions with high rupture rate in literatures. Endovascular treatment may be a feasible alternative for TPCoA aneurysms. Primary coiling, as well as adjunctive strategies, such as stent-assisted coiling or dual catheter techniques may be considered. Further study in a larger population is necessary.