Predictors of Oculomotor Nerve Palsy with Posterior Communicating Aneurysm Clipping in a Surgically Treated Series of 585 Patients: A Single-Center Study

BACKGROUND

Oculomotor nerve palsy (OMNP) is a known risk in surgical management of intracranial aneurysms. The aim of this study was to determine the risk factors for surgery-induced OMNP.

METHODS

This retrospective study examined 585 patients with posterior communicating artery aneurysms treated surgically between January 2000 and July 2019. The patients were categorized into 2 groups according to whether they experienced OMNP. Multiple factors, including sex, age, history of subarachnoid hemorrhage, Hunt and Hess grade, Fisher grade, preoperative time, sizes, sides, number, orientation, intraoperative rupture, and morphology, were analyzed to identify factors associated with surgery-induced OMNP.

RESULTS

The overall OMNP rate was 4.4%. In univariate analysis, large size (P < 0.001), posterior infratentorial projection (P = 0.003), number of subarachnoid hemorrhages (P = 0.005), and late preoperative time (P < 0.001) were associated with increased risk of OMNP. Overall, multivariate logistic regression analysis showed that size (10.1-25 mm: odds ratio [OR] 30.083, P = 0.001, 95% confidence interval [CI], 3.703-244.419; >25 mm: OR 62.179, P = 0.012, 95% CI, 2.402-1609.418), intraoperative rupture (OR 3.018, P = 0.035, 95% CI, 1.083-8.412), and preoperative time (>14 days: OR 10.985, P < 0.001, 95% CI, 3.840-31.428) were independent risk factors of surgery-induced OMNP.

CONCLUSIONS

This study showed that size, intraoperative rupture, and preoperative time were independent predictors of surgery-induced OMNP. Use of advanced technologies during the operation can assist in avoiding this complication.

Effects of endovascular treatment and prognostic factors for recovery of oculomotor nerve palsy caused by posterior communicating artery aneurysms: a multi-center retrospective analysis

Background

Oculomotor nerve palsy (ONP) may result from posterior communicating artery (PcomA) aneurysms. We aimed to evaluate the resolution of ONP after endovascular treatment with the intention of clarifying predictors of nerve recovery in a relatively large series.

Methods

A total of 211 patients with ONP caused by PcomA aneurysms underwent endovascular coiling between May 2010 and December 2020 in four tertiary hospitals. We evaluated the demographics, clinical characteristics, aneurysm morphology parameters and ONP resolution to analyze the predictors of ONP recovery using univariate and multivariate analyses.

Results

At the last available clinical follow-up, ONP resolution was complete in 126 (59.7%) patients, partial in 73 (34.6%) patients, and no recovery in 12 (5.7%) patients. The median resolution time after endovascular treatment was 55 days (interquartile range: 40–90 days). In multivariate analysis, degree of ONP (incomplete palsy) on admission (OR 5.396; 95% CI 2.836–10.266; P < 0.001), duration of ONP (≤ 14 days) before treatment (OR 5.940; 95% CI 2.724–12.954; P < 0.001) were statistically significant predictors of complete recovery of ONP. In the subgroup analysis of patients with unruptured aneurysms, aspirin showed a higher complete recovery rate in univariate analysis (OR 2.652; 95% CI 1.057–6.656; P = 0.038).

Conclusion

Initial incomplete ONP and early management might predict better recovery of ONP after endovascular treatment.

Risk factors of recurrence after endovascular embolization of posterior communicating artery aneurysms

BACKGROUND AND OBJECTIVE

To determine the risk factors for recurrence after endovascular embolization of posterior communicating artery aneurysms (PcomA).

METHODS

We retrospectively analyzed a cohort of 163 patients harboring 172 PocmAs who were treated with endovascular embolization from January 2019 to December 2020. The patients were divided into recurrence and stable groups depending on outcome. Univariate and logistic regression analyses were performed to determine the potential risk factors of recurrence during follow-up.

RESULTS

Of the total 163 patients harboring 172 aneurysms, 107 were treated with simple coil occlusion and 65 were treated with stent-assisted coil embolization. There were significant differences in aneurysm sizes and use of non-stent-assisted coil embolizations between the groups (P < 0.05). The incidence of saccular aneurysm and Raymond grade were significantly higher in the recurrent group than in the stable group (P < 0.01). After variable selection, Raymond grade, aneurysm size, saccular aneurysm and non-stent-assisted coil embolization were included in further analysis. Binary logistic regression analysis revealed significant associations with non-stent-assisted coil embolization (P = 0.007), packing density (P < 0.001) and Raymond grades II (P < 0.001) and III (P = 0.002).

CONCLUSION

Non-stent-assisted coil embolization, as well as packing density and Raymond grades II grade III are associated with recurrence after endovascular treatment of PcomA.

Premammillary artery infarction after microsurgical clipping of unruptured posterior communicating artery aneurysm: risk factors and surgical and anatomical considerations

Posterior communicating artery (PCoA) aneurysm is common and sometimes requires microsurgery; however, as data on premammillary artery (PMA) infarction after clipping is scarce, we retrospectively reviewed cases of post-clipping PMA infarction to analyze incidence, independent risk factors of infarction, and anatomical considerations. Data from 569 consecutive patients who underwent microsurgical clipping for unruptured PCoA aneurysm between January 2008 and December 2020 were included. Patients were categorized into the normal or the PMA infarction group. Statistical analyses and comparisons between the two groups were used to determine the influence of various factors. The normal group included 515 patients while the PMA infarction group had 31. The mean length of hospital stay was significantly longer in the PMA infarction group (10.3 ± 9.1 days) than in the normal group (6.5 ± 6.4 days; p < 0.0001). The distribution of Glasgow Outcome Scale at discharge was significantly different between the two groups (p ≤ 0.0001) but was not so at 6 months after discharge (p = 0.0568). Multivariate logistic regression analysis identified aneurysm size (odds ratio [OR], 1.194; 95% confidence interval [CI], 1.08-1.32; p = 0.0005) and medial direction of aneurysm (OR, 4.615; 95% CI, 1.224-17.406; p = 0.0239) as independent risk factors of post-clipping PMA infarction. Surgeons must beware of PMA infarction after clipping of large aneurysms that are medial in direction. Intraoperative verification of the patency of the PCoA and the PMA from various angles using various intraoperative methods can reduce morbidity due to PMA infarction.

Higher oscillatory shear index is related to aneurysm recanalization after coil embolization in posterior communicating artery aneurysms

BACKGROUND

The recurrence rate of posterior communicating artery (Pcom) aneurysms after endovascular treatment (EVT) is higher than that for aneurysms located in other sites. However, it is still unclear what mechanisms are responsible for the recanalization of cerebral aneurysms. In this investigation, we compared hemodynamic factors related with recanalization of Pcom aneurysms treated by endoluminal coiling using computational fluid dynamics (CFD) with high-resolution three-dimensional digital subtraction angiography images.

METHODS

Twenty patients were enrolled. A double-sinogram acquisition was performed with and without contrast injection after coil embolization to get true blood vessel lumen by relatively complementing the first sinogram with the second. Adaptive Cartesian meshing was performed to produce vascular wall objects for CFD simulation. The boundary condition for inlet (ICA) was set for dynamic velocity according to the cardiac cycle (0.8 s). Hemodynamic parameters were recorded at two specific points (branching point of Pcom and residual sac). The peak pressure, peak WSS, and oscillatory shear index (OSI) were recorded and analyzed.

RESULTS

The median age was 61.0 years, and 18 patients (90%) were female. During a median follow-up of 12 months, seven (35%) treated aneurysms showed recanalization. The median aneurysm volume was significantly higher, and aneurysm height and neck sizes were significantly longer in the recanalization group than those in the stable group. At the branching point of the Pcom, the peak pressure, peak WSS, or OSI did not significantly differ between the two groups. The only statistically significant hemodynamic parameter related with recanalization was the OSI at the aneurysm point. Multivariate logistic regression showed that with an increase of 0.01 OSI at the aneurysm point, the odds ratio for the aneurysm recanalization was 1.19.

CONCLUSIONS

A higher OSI is related with recanalization after coil embolization for a Pcom aneurysm.

Recurrence and risk factors of posterior communicating artery aneurysms after endovascular treatment

BACKGROUND

Endovascular treatment (EVT) of posterior communicating artery aneurysms (PcomA) is challenging because of posterior communicating artery (Pcom) architecture. Additionally, these aneurysms have a high risk of recanalization compared with those located elsewhere.

METHODS

The radiographic findings of 171 patients treated with EVT at two institutions were retrospectively reviewed. Univariate and multivariate analyses were performed, and subgroup analyses were performed based on Pcom characteristics.

RESULTS

Recanalization of PcomAs occurred in 53 patients (30.9%). Seven patients (4.0%) were retreated (six endovascularly and one with microsurgical clipping). The mean follow-up duration was 27.7 months (range: 3.5-78.6). The maximum diameter (odds ratio [OR] 1.23, P = .006, 95% CI 1.07-1.44), a Raymond-Roy classification of grade II or III (OR 2.26, P = .03, 95% CI 1.08-4.82), and the presence of reinforcement (balloon or/and stent, OR 0.44, P = .03, 95% CI 0.20-0.91) were associated with recanalization using multivariate logistic regression. Significant differences were found in maximum aneurysm diameter (P = .03) between normal- and fetal-type Pcoms on analysis of variance.

CONCLUSIONS

The recanalization rate of PcomAs after EVT was 30.9%; the retreatment rate was 4.0%. Maximum diameter, Raymond-Roy classification, and presence of reinforcement were significantly associated with recanalization but not associated with fetal-type Pcom. Aneurysm size was larger in patients with a fetal-type Pcom than in those with a normal Pcom. Pcom size was not related to recanalization rate.

Dual Microcatheter Technique for Coiling of Intracranial Aneurysms: 2-Dimensional Operative Video

Primary coiling of large intracranial aneurysms with complex morphology, such as multiple lobes and a wide neck, is challenging. In these aneurysms, achieving adequate intra-aneurysmal packing density while preventing coil herniation into the parent vessel may be difficult with traditional coiling technique. In the setting of acute aneurysm rupture, alternative treatment options such as stent-assisted coiling or flow diversion may not be feasible due to the need for dual antiplatelets. In this video, we demonstrate the use of a dual microcatheter technique to achieve adequate packing density within a wide-necked, bilobed saccular aneurysm. The patient presented with a ruptured posterior communicating artery aneurysm with Hunt and Hess grade 2 and Fisher grade 4 subarachnoid hemorrhage. A biaxial catheter system was used for primary coiling of the aneurysm. Two .017-inch microcatheters were strategically positioned in the aneurysm lobes. The first coil was deployed through the distal catheter, which created a basket for the second coil to be deployed through the proximal microcatheter. Subsequent simultaneously deployed coils were weaved into each other to form a stable coil mass that prevented coil herniation into the parent vessel. Complete obliteration of the aneurysm was achieved. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, Inc., January 2020. With permission. 10.1093/ons/opab074 VIDEO 1 Dual Microcatheter Technique for Coiling of Intracranial Aneurysms: 2-Dimensional Operative Video opab074Media1 6236960343001.

Clipping versus coiling in the treatment of oculomotor nerve palsy induced by unruptured posterior communicating artery aneurysms: A meta-analysis of cohort studies

BACKGROUND

Although the superiority of clipping compared to coiling on the oculomotor nerve palsy (ONP) recovery for ruptured posterior communicating artery aneurysms (PcomAAs) has been widely accepted, which treatment modality is better in the treatment of ONP induced by unruptured PcomAAs still remains unclear.

METHODS

A meta-analysis of studies that compared clipping with coiling was performed after a literature search. Perioperative data and clinical outcome were extracted. Analysis on the effect of the two treatment modalities was then performed.

RESULTS

Nine eligible studies with a total of 136 patients met the inclusion criteria. There was a significant difference in the total efficiency (any degree of improvement) on ONP favoring clipping [RR= 1.21, 95%CI (1.01, 1.44), p = 0.04], the effect was most notable for complete recovery of ONP after having suffered preoperative partial palsy [RR= 0.72, 95%CI (0.55, 0.95), p = 0.02]. There was neither a significant difference regarding the complete recovery of ONP [RR= 1.11, 95%CI (0.77, 1.61), p = 0.58] nor the frequency of complications [RR= 0.07, 95%CI (0.00, 1.10), p = 0.06]. Also when subdividing there was no significant difference in complete recovery of ONP in patients who had initially suffered a complete ONP [RR= 0.79, 95%CI (0.38, 1.64), p = 0.53] and partial ONP [RR= 1.16, 95%CI (0.65, 2.08), p = 0.61] between clipping and coiling.

CONCLUSIONS

A superiority of clipping over coiling for the improvement of ONP secondary to unruptured PcomAAs was found. Patients with partial ONP were more likely to attain a complete resolution of ONP, as compared to complete ONP.

Oculomotor nerve palsy due to posterior communicating artery aneurysm: Clipping vs coiling

OBJECTIVE

Posterior communicating artery aneurysms (PCoAA) usually present with brain hemorrhage, but they might present with oculomotor nerve palsy (ONP) in about one out of five patients. Treatment options include endovascular coiling and surgical clipping. The present analysis aims to compare the two treatment options for ONP due to PCoAA in terms of complete recovery and related parameters.

METHODS

A comprehensive literature search was performed for studies published between 2000 and 2019 on ONP due to PCoAA. The included studies were divided into two categories-surgical clipping (group A) and endovascular coiling (group B). The collected data were statistically processed with SPSS version 25.

RESULTS

There was a significant difference between the two treatment groups regarding complete recovery of ONP (P<0.001), suggesting superiority of the surgical clipping. The correlation analysis showed no correlations for group A. Group B had negative and positive correlations, showing that endovascular coiling results in higher rates of complete ONP recovery for elderly patients.

CONCLUSION

Surgical clipping is superior to endovascular coiling in terms of complete recovery among patients with ONP due to PCoAAs. Endovascular coiling seems to benefit older patients. While no recommendations exist for the treatment of ONP due to intracranial aneurysms, an increasing number of studies imply the superiority of operative clipping.

Anterior Temporal Approach for Clipping Posterior-Projecting Supraclinoid Carotid Artery Aneurysms: A More Lateral Corridor to Better Visualize the Aneurysm Neck and Related Branches

BACKGROUND

Direct visualization of the aneurysm neck and its related branches during microsurgical clipping of supraclinoid internal carotid artery (SICA) aneurysms using a standard pterional approach may be difficult, especially when aneurysms are posteriorly projected. We evaluated the efficacy and safety of an anterior temporal approach for clipping posterior-projecting SICA aneurysms.

METHODS

Between December 2017 and March 2020, 26 patients with posterior-projecting SICA aneurysms who received microsurgical clipping via an anterior temporal approach were retrospectively reviewed. The percentage of complete aneurysm obliteration, intraoperative visualization, and preservation of related branches were evaluated.

RESULTS

Aneurysm locations were the posterior communicating artery (PCoA) (internal carotid artery [ICA]-PCoA) in 22 patients (84.6%), the anterior choroidal artery (AChA) (ICA-AChA) in 3 patients (11.5%), and both locations in 1 patient (3.9%). Complete aneurysm obliteration was achieved in all patients. For ICA-PCoA aneurysms in which the PCoA was preoperatively identified, the artery was intraoperatively identified in all cases and preserved 100% after surgery. For ICA-AChA aneurysms, AChAs were intraoperatively identified and preserved in all cases after surgery. Procedural-related infarction was 8.7% for ICA-PCoA aneurysms and 7.7% for all SICA aneurysms. Transient oculomotor nerve palsy was found in 2 patients (7.7%). No postoperative temporal contusion was detected. A good outcome at 3 months after surgery was achieved in 90% of patients for good clinical-grade subarachnoid hemorrhage and unruptured cases.

CONCLUSIONS

The anterior temporal approach is safe and effective for clipping SICA aneurysms with posterior projection, with a high preservation rate of the related branches.

Are Fetal-Type Posterior Cerebral Arteries Associated With an Increased Risk of Posterior Communicating Artery Aneurysms?

BACKGROUND

Fetal-type posterior cerebral arteries (F-PCAs) might result in alterations in hemodynamic flow patterns and may predispose an individual to an increased risk of posterior communicating artery aneurysms (PCoAAs).

OBJECTIVE

To determine the association between PCoAAs and the presence of ipsilateral F-PCAs.

METHODS

We retrospectively reviewed the radiographic findings from 185 patients harboring 199 PCoAAs that were treated at our institution between 2005 and 2015. Our study population consisted of 4 cohorts: (A) patients with 171 internal carotid arteries (ICAs) harboring unilateral PCoAAs; (B) 171 unaffected ICAs in the same patients from the first group; (C) 28 ICAs of 14 patients with bilateral PCoAAs; and (D) 180 ICAs of 90 patients with aneurysms in other locations. We then determined the presence of ipsilateral F-PCAs and recorded all aneurysm characteristics.

RESULTS

Group A had the highest prevalence of F-PCAs (42%) compared to 19% in group B, 3% in group C, and 14% in group D (odds ratio A : B = 3.041; A : C = 19.626; and A : D = 4.308; P < .001). PCoAAs were associated with larger diameters of the posterior communicating arteries (median value 1.05 vs 0.86 mm; P = .001). The presence of F-PCAs was associated with larger sizes of the aneurysm necks (median value 3.3 vs 3.0 mm; P = .02).

CONCLUSION

PCoAAs were associated with a higher prevalence of ipsilateral F-PCAs. This variant was associated with larger sizes of the aneurysm necks but was not associated with the sizes of the aneurysm domes or with their rupture statuses.

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.

Simple assessment of the localization of posterior communicating artery aneurysms to the anterior petroclinoid ligament

The microsurgical management of posterior communicating artery (PCoA) aneurysms can be modified depending on their localization, with respect to the tentorial edge consisting of the anterior petroclinoid ligament (APCL). However, the imaging of APCL has been impractical to date. In this study, we evaluated a simple method for assessing the relationship between PCoA aneurysms and APCL, using three-dimensional computed tomographic angiography (3D-CTA). We retrospectively reviewed all surgically treated cases of PCoA aneurysms via the pterional approach in our institute from May 2013 to August 2018. To predict the localization of the aneurysms, three anatomical lines were drawn on non-subtracted volumetric 3D-CTA as follows: 1. the apex of the anterior clinoid process to the posterior border of the trigeminal depression of the petrosal bone (AACP-PBTD); 2. AACP to the superior edge of the arcuate eminence (AACP-SEAE); 3. the base of the ACP to the superior edge of the arcuate eminence (BACP-SEAE). The relative location of each line to the PCoA aneurysms was compared with actual intraoperative findings. Fifty-six aneurysms were included. The sensitivity, specificity, and positive and negative predictive values of the superior localization of the aneurysm of the AACP-TDPB line were 93.8%, 40.0%, 38.5%, and 94.1%, respectively. Those of the AACP-SEAE line were 93.8%, 42.5%, 39.5, and 94.4%, respectively. In contrast, those of the BACP-SEAE line were 93.8%, 97.5%, 93.8%, and 97.5%, respectively. The BACP-SEAE line is a simple and practical landmark in predicting APCL.

Pure Acute-on-Chronic Subdural Hematoma Due to Ruptured Posterior Communicating Artery Aneurysm: Unsuspecting Entity

BACKGROUND

Even though rarely reported as a cause of pure subdural hematoma (SDH), aneurysmal rupture should be suspected in patients with spontaneous SDH without coagulopathy.

CASE DESCRIPTION

We report a case of acute-on-chronic SDH in a 55-year-old lady with cerebral herniation due to a ruptured posterior communicating artery aneurysm. She was managed with single-stage SDH evacuation along with clipping of the aneurysm.

CONCLUSIONS

Computed tomography angiography of the head is advisable in patients with spontaneous SDH without coagulopathy. Pure SDH as compared with SDH associated with subacute hemorrhage, intraventricular hemorrhage, or intracerebral hemorrhage due to aneurysmal rupture has a good outcome.

Apolipoprotein E polymorphism and the risk of aneurysmal subarachnoid hemorrhage in a South Indian population

Background

The rupture of a brain aneurysm causes bleeding in the subarachnoid space. This is known as aneurysmal subarachnoid hemorrhage (aSAH). We evaluated the association of apolipoprotein E (APOE) polymorphism and the risk of aSAH in a South Indian population.

Methods

The study was performed on 200 subjects with aSAH and 253 healthy control subjects. Blood samples (5 ml) were used to isolate DNA and genotyping was performed for rs7412 and rs429358 using a Taqman allelic discrimination assay. Statistical software R.3.0.11 was used to statistically analyze the data and a p value < 0.05 was considered as statistically significant.

Results

We found a significant association with the risk of aSAH in ε3/ ε4 genetic model (OR = 1.91, 95% CI = 1.16-3.14, p = 0.01). However, in the other genetic models and allele frequency, there was no significant association with the risk of aSAH. In subtyping, we found a significant association of ε2 allele frequency with posterior communicating artery (PCOM) aneurysm (OR = 3.59, 95% CI = 1.11-11.64, p = 0.03).

Conclusion

Our results suggest that APOE polymorphism has an influence on the risk of aSAH in this South Indian population, specifically in the PCOM subtype.

CTA analysis and assessment of morphological factors related to rupture in 413 posterior communicating artery aneurysms

Posterior communicating artery (PcomA) aneurysms are frequently encountered, but there are few publications on their morphology. A growing number of aneurysms are incidental findings, which makes evaluation of rupture risk important. Our goal was to identify morphological features and anatomical variants associated with PComA aneurysms and to assess parameters related to rupture. We studied CT angiographies of 391 consecutive patients treated between 2000 and 2014 at a single institution. We determined clinically important morphological parameters and performed univariate and multivariate analysis. There were a total of 413 PComA aneurysms: 258 (62%) were ruptured and 155 (38%) unruptured. Ruptured PComA aneurysms had the potential to cause severe bleeding with IVH and/or temporal ICH (n = 170, 66% of ruptured). The main types of PComA origin were classified as follows: (1) separate (32%), (2) side by side (21%) and (3) a joint neck with the aneurysm (6%). After the multivariate logistic regression, the morphological parameters related to PComA aneurysm rupture were an irregular aneurysm dome, neck diameter, and aspect ratio >1.5. The most marked morphological features of the PComA aneurysms were: saccular nature (99%), infero-posterior dome orientation (42%), infrequency of large or giant aneurysms (4%), narrow neck compared to the aneurysm size, PComA originating directly from the aneurysm neck or the dome (28%), and fetal or dominant PComA on the side of the aneurysm (35%). There were location-related parameters that were more strongly associated with PComA aneurysm rupture than aneurysm size: an irregular aneurysm dome, larger diameter of the aneurysm neck and aspect ratio >1.5.

Microneurosurgical Management of Posterior Communicating Artery Aneurysm: A Contemporary Series from Helsinki

OBJECTIVE

The objectives of this study were to analyze microsurgical techniques and to determine correlations between microsurgical techniques and the radiographic findings in the microneurosurgical treatment of posterior communicating artery aneurysms (PCoAAs).

METHODS

We retrospectively analyzed radiographic findings and videos of surgeries in 64 patients with PCoAAs who underwent microsurgical clipping by the senior author from August 2010 to 2014.

RESULTS

From 64 aneurysms, 30 (47%) had acute subarachnoid hemorrhage (SAH) that necessitated lamina terminalis fenestration (odds ratio [OR], 67.67; P < 0.001) and Liliequist membrane fenestration (OR, 19.62; P < 0.001). The low-lying aneurysms significantly necessitated the coagulation of the dura covering the anterior clinoid process (ACP) (OR, 7.43; P = 0.003) or anterior clinoidectomy (OR, 91.0; P < 0.001). We preferred straight clips in 45 (83%) of 54 posterolateral projecting aneurysms (OR, 45.0; P < 0.001), but preferred curved clips for posteromedial projecting aneurysms (OR, 6.39; P = 0.008). The mean operative time from the brain retraction to the final clipping was 17 minutes and 43 seconds. Postoperative computed tomography angiography revealed complete occlusion of 60 (94%) aneurysms. Three (4.6%) patients with acute SAH suffered postoperative lacunar infarction.

CONCLUSIONS

For ruptured aneurysms, lamina terminalis and Liliequist membrane fenestration are useful for additional cerebrospinal fluid drainage. For low-lying aneurysms, coagulation of the dura covering the ACP or tailored anterior clinoidectomy might be necessary for exposing the proximal aneurysm neck. Type of clips depends on the direction of projection. The microsurgical clipping of the PCoAAs can achieve good immediate complete occlusion rate with low postoperative stroke rate.

Retrograde Stent-assisted Coil Embolization of Wide-neck or Branch-incorporated Posterior Communicating Artery Aneurysm

Endovascular coil embolization using a balloon- or stent-assisted technique for the treatment of wide-necked posterior communicating artery (PcomA) aneurysms is well established. However, complete aneurysm occlusion with preservation of the PcomA can be difficult in case of wide-neck aneurysms with a PcomA incorporation. We present two cases of stent-assisted coil embolization using a retrograde approach through the posterior circulation for wide-neck or branch-incorporated PcomA aneurysms. Retrograde stenting was successful without periprocedural complications. These aneurysms were completely occluded. The patency of the PcomA was maintained in all cases.

Association between anatomical variations of the posterior communicating artery and the presence of aneurysms

OBJECTIVES

Posterior communicating artery aneurysms (PcoAA) account for 30-35% of intracranial aneurysms. The anatomical factors involved in the formation of PCoAA are poorly known. The study aimed to investigate the anatomical variations in the posterior communicating artery (PcoAs) and the presence of PCoAA.

METHODS

All 154 patients hospitalized from January 2008 to December 2013 at the department of neurology of our hospital were included in this study; 76 were confirmed with PCoAA upon cerebral angiography and 78 were confirmed without cranial artery aneurysm (controls). According to the blood supply pattern, variations of the PCoAA were classified as Type P0, P-I, or P-II. The angles of C7 and C6 of the internal carotid artery on each side were analyzed.

RESULTS

Compared with controls, patients with PCoAA had a higher frequency of abnormal posterior communicating artery (Types P-I and P-II) (p < 0.001). The angles of C7 and C6 on the contralateral side in the PCoAA group were significantly greater than on the affected side, and significantly lesser than in controls (p < 0.001). There was no difference in the angle between the culprit artery and the contralateral one.

DISCUSSION

Abnormal PCoAs (Types P-I and P-II) might be more vulnerable to PCoAA development, and Type P-II was the most vulnerable. There was a correlation between the angles of C7 and C6 part of the internal carotid artery and the presence of symptomatic PCoAA, with smaller angles being associated with increased frequency of symptomatic PCoAA.

[Endovascular coiling of a «true» posterior communicating artery aneurysm]

True posterior communicating artery aneurysms originate exclusively from the wall of this artery and should be differentiated from aneurysms of the posterior communicating segment of the distal carotid artery. As these lesions are rare, their anatomical relationships have been poorly described; likewise, reports concerning their endovascular treatment are extremely rare and the technical aspects poorly detailed. A case of a patient with a true aneurysm of the left posterior communicating artery treated by endovascular coiling is presented. A literature review was also conducted to illustrate the anatomical and technical details relevant to achieving its successful treatment.

Isolated, contralateral trochlear nerve palsy associated with a ruptured right posterior communicating artery aneurysm

Trochlear nerve palsy associated with spontaneous subarachnoid hemorrhage (SAH) is known to be a rare malady. We report here on a patient who suffered with left trochlear nerve palsy following rupture of a right posterior communicating artery aneurysm. A 56-year-woman visited our emergency department with stuporous mental change. Her Hunt-and-Hess grade was 3 and the Fisher grade was 4. Cerebral angiography revealed a ruptured aneurysm of the right posterior communicating artery. The aneurysm was clipped via a right pterional approach on the day of admission. The patient complained of diplopia when she gazed to the left side, and the ophthalmologist found limited left inferolateral side gazing due to left superior oblique muscle palsy on day 3. Elevated intracranial pressure, intraventricular hemorrhage or a dense clot in the basal cisterns might have caused this trochlear nerve palsy.