A review of the management of posterior communicating artery aneurysms in the modern era

An understimated maneuver for oculomotor nerve palsy due to posterior communicating artery aneurysm: the opening of the anterior petroclinoid ligament. A technical note

Posterior communicating artery aneurysms (PcomAs) present with oculomotor nerve (OMN) palsy in 20-30% of cases, and the sudden onset of OMN palsy has to raise the suspicion of rupture, until proven otherwise. The surgical technique is described in a stepwise fashion. An illustrative case is reported: a 57-year-old female was admitted to our department with the diagnosis of a right sided-PcomA. Three months before the admission, when she harbored with the acute onset of complete ptosis, diplopia, orbital pain, impairment of the medial, upward, and downward gaze, with no pupil dysfunction. The origin of the Pcom and the neck of the aneurysm were easily identified and the aneurysm was clipped. Then, we followed the OMN and cut for less than 4 mm the above-lying anterior petroclinoid ligament (APL) to obtain nerve release. Although few cases are described in the literature, and ours represents a single case, we support that this maneuver should be introduced in the clinical practice of expert neurosurgeons dealing with vascular pathologies, such as the opening of the falciform ligament occurs for the decompression of the optical nerve.

Hemodynamic alterations of flow diverters on aneurysms at the fetal posterior communicating artery: A simulation study using CFD to compare the surpass streamline, pipeline flex, and tubridge devices

PURPOSE

Traditional flow diverters (FDs) for treating aneurysms at the fetal posterior communicating artery are unsatisfactory. Surpass Streamline is a novel FD with different mesh characteristics; however, the outcomes for such aneurysms remain unclear. This study aimed to compare hemodynamic alterations induced by Surpass Streamline, Pipeline Flex, and Tubridge devices and explore possible strategies for aneurysms at the fetal posterior communicating artery.

METHODS

Two simulated aneurysms (Case 1, Case 2) were constructed from digital subtraction angiography (DSA). The three FDs were virtually deployed, and hemodynamic analysis based on computational fluid dynamics was performed. Hemodynamic parameters, including the sac-averaged velocity magnitude (Velocity), high-flow volume (HFV), and wall shear stress (WSS), were compared between each FD and the untreated model (control). Surpass Streamline was performed in real life for two aneurysms and the clinical outcomes were collected for analysis.

RESULTS

Compared to the control, the Surpass resulted in the most significant reduction in flow. In Case 1, the Velocity, HFV, and WSS were reduced by 51.6%, 78.1%, and 64.3%, respectively. In Case 2, the Velocity, HFV, and WSS were reduced by 48.0%, 81.1%, and 65.3%, respectively. Tubridge showed slightly larger changes in hemodynamic parameters than Pipeline. In addition, our analysis suggested that metal coverage was correlated with the WSS, Velocity, and HFV. The postoperative DSA showed that the aneurysm was nearly occluded in Case 1 and decreased in Case 2.

CONCLUSION

Compared to that with the Pipeline and Tubridge, the Surpass resulted in the greatest reduction in hemodynamic parameters and might be effective for aneurysms at the fetal posterior communicating artery. Virtual FD deployment and computational fluid dynamics analysis may be used to predict the treatment outcomes.

Hemodynamic differences of posterior communicating artery aneurysms between adult and fetal types of posterior cerebral artery

BACKGROUND

The recanalization of posterior communicating artery (PCoA) aneurysms after endovascular treatment has been analyzed by various factors. However, the differences between adult and fetal types of posterior cerebral artery (PCA) have not been fully investigated. The main aim of this study was to investigate hemodynamic differences of PCoA aneurysms between adult and fetal types using computational fluid dynamics (CFD).

METHODS

Fifty-five PCoA aneurysms were evaluated by 3D CT angiography and divided into unruptured aneurysms with adult-type or fetal-type PCAs (19 cases, UA group; 9 cases, UF group) and ruptured aneurysms with adult-type or fetal-type PCAs (17 cases, RA group; 10 cases, RF group). These native aneurysms were analyzed by CFD regarding morphological and hemodynamic characteristics. To evaluate simulated endovascular treatment of aneurysms, CFD was performed using porous media modeling.

RESULTS

Morphologically, the RA group had significantly smaller parent artery diameter (2.91 mm vs. 3.49 mm, p=0.005) and higher size ratio (2.54 vs. 1.78, p=0.023) than the RF group. CFD revealed that the UA group had significantly lower oscillatory shear index (OSI) (0.0032 vs. 0.0078, p=0.004) than the UF group and that the RA group had lower WSS (3.09 vs. 11.10, p=0.001) and higher OSI (0.014 vs. 0.006, p=0.031) than the RF group, while the RF group presented significantly higher intra-aneurysmal flow velocity (0.19 m/s vs. 0.061 m/s, p=0.002) than the RA group. Porous media modeling of simulated treatment revealed higher residual flow volume in the fetal-type groups.

CONCLUSIONS

These results suggested that PCoA aneurysms with fetal-type PCAs had different morphological features and hemodynamic characteristics compared with those with adult-type PCAs, leading to high risks of recanalization.

How I do it? Preoperative Microsoft HoloLens 2 planning-assisted surgical clipping of a fetal posterior cerebral artery aneurysm

BACKGROUND

The treatment of intracranial aneurysms has predominantly shifted towards endovascular strategies, but complex cases still necessitate microsurgery. Preoperative stimulation can be beneficial for inexperienced young neurosurgeons in preparing for safe microsurgery.

METHOD

A 72-year-old female with a left irregular fetal posterior cerebral artery (PCA) aneurysm underwent clipping repair. Microsoft HoloLens 2, utilizing mixed reality technology, was employed for preoperative stimulation and anatomical study. During the operation, we successfully identified the planned relationship between the aneurysm and the fetal PCA. The patient was cured without any complications.

CONCLUSION

We hope that this report will highlight the significance of Microsoft HoloLens 2 in microsurgical planning and education.

Flow Diverter Performance in Aneurysms Arising From the Posterior Communicating Artery: A Systematic Review and Meta-Analysis

BACKGROUND

Flow diverters (FDs) have demonstrated a safe and effective profile. However, the use of FDs for posterior communicating artery (PComA) aneurysms remains controversial.

OBJECTIVE

To evaluate the safety and effectiveness of FDs for PComA aneurysms using a systematic review and meta-analysis of the literature.

METHODS

We performed a systematic search from inception until June 2022 for flow diversion in PComA aneurysms. Primary effectiveness was the rate of complete aneurysm occlusion defined by Raymond-Roy class 1. Primary safety outcomes were treatment-related ischemic/hemorrhagic (composite) events causing morbidity and mortality. Secondary safety was PComA patency at follow-up. Random-effects meta-analyses were used to calculate proportions, and statistical heterogeneity was assessed.

RESULTS

A total of 13 studies with 397 patients harboring 403 aneurysms were included. Mean age was 48 years, and the mean aneurysm size was 5.3 mm. Most aneurysms were unruptured (65%). Complete occlusion at final follow-up was 73% (CI 66%-79%), and adjunctive coils were used in 10% of aneurysms. Retreatment rate was 2% (CI 0%-9%). The primary safety composite outcome was 4% (CI 3%-7%), and mortality was 1%. PComA patency at final follow-up was 76% (CI 57%-89%). Subgroup analysis, patients with fetal PComAs had a lower complete occlusion rate (42% fetal PComA vs 77%, psubgroupdifference = <.01).

CONCLUSION

The performance of FDs in PComA aneurysms is comparable with outcomes found in other subtypes of supraclinoid aneurysms. Effectiveness was acceptable and safety favorable. However, effectiveness was suboptimal in patients with fetal-type PComAs; alternative treatments should be considered in these cases.

Impact of branch arteries on efficacy of endoluminal flow diverters: Insights from posterior communicating artery aneurysms

BACKGROUND

Flow diverter treatment may inevitably require jailing of the branch vessels. While the patency of covered branch arteries and associated safety risks have been a topic of substantial interest, the question of whether the characteristics of branch vessels affect flow diversion's efficacy remains unanswered. In this study, we aimed to assess the impact of branch arteries on the efficacy of endoluminal flow diverters, specifically focusing on posterior communicating artery (Pcomm) aneurysms.

METHODS

Following PRISMA guidelines, we systematically searched the MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane databases with predefined keywords. Studies providing data for flow diversion outcomes in Pcomm aneurysms were included. Outcomes of interest included complete and adequate aneurysm obliteration, ischemic and hemorrhagic complications, and Pcomm occlusion in the follow-up period. A random or fixed effects model was used to calculate the odds ratios (ORs) and pooled event rates with their corresponding confidence intervals (CI).

RESULTS

The overall complete and adequate aneurysm occlusion rates were 72.25% (95% CI: 64.46-78.88%) and 88.37% (95% CI: 84.33-92.6), respectively. Fetal-type Pcomm aneurysms had significantly lower complete aneurysm occlusion rates than the nonfetal-type Pcomm aneurysms (OR: 0.12, 95% CI: 0.05-0.29). Overall ischemic and hemorrhagic complication rates were 2.62% (95% CI = 0.71-5.32) and 0.71% (95% CI: 0-2.24), respectively. There were no significant associations between Pcomm morphology and complications (OR: 3.61, 95% CI = 0.42-31.06 for ischemic complications and OR: 2.31, 95% CI = 0.36-14.6 for hemorrhage). Overall Pcomm occlusion rate was 32.04% (95% CI = 19.96-47.13), and the Pcomm patency was significantly lower in nonfetal-type Pcomm aneurysms (OR: 0.10, 95% CI = 0.02-0.44).

CONCLUSION

Our meta-analysis suggests that flow diversion is a safe treatment option for Pcomm aneurysms, regardless of fetal-type Pcomm morphology. However, on the other hand, our findings indicate that Pcomm anatomy or the presence of jailed large branches can affect the efficacy of flow diverter treatment.

Fetal-type posterior cerebral artery and association of rupture in posterior communicating artery aneurysms: A systematic review and meta-analysis

BACKGROUND

The morbidity and mortality of intracranial aneurysm rupture motivate the risk evaluation of the patient´s characteristics and aneurysm's morphology. Brain vessel variants lead to hemodynamic changes that could increase risk. This study aims to evaluate the fetal posterior cerebral artery (fPCA) as a risk factor for the formation, rupture, and recurrence of the posterior communicating artery (PComA) aneurysm.

METHODS

A search strategy was performed in MEDLINE, Scopus, Web of Science, and EMBASE databases for studies that evaluated the risk of appearance, rupture, and recurrence of PComA aneurysms with the presence of fPCA. Newcastle-Ottawa Scale and AXIS were used for quality assessment. The primary and secondary outcomes were evaluated and interpreted with an odds ratio (OR) and their 95% confidence intervals (CI).

RESULTS

A total of 577 articles were reviewed. Thirteen studies were included for the qualitative analysis, and ten studies for the meta-analysis. All cohort studies were classified as poor quality, and all cross-sectional studies with moderate risk. The unadjusted OR resulted in 1.57 (n = 6, 95% CI 1.13-2.19, p = <0.001, I² =0%) between the presence of fPCA and PComA aneurysm rupture.

CONCLUSION

There is a significant association of aneurysm formation and rupture of PComA aneurysms in the presence of fPCA. This may be triggered by the hemodynamic alterations caused by the variation, leading to changes in the vessel wall.

Management of saccular superior cerebellar artery aneurysms: The Buffalo experience case series and systematic review

BACKGROUND

Results of the management of superior cerebellar artery (SCA) aneurysms are typically reported in combination with those for all posterior circulation aneurysms. We report our experience with the management of SCA aneurysms and a systematic review of the endovascular management of these rare aneurysms.

METHODS

Patients with saccular SCA aneurysms that were not associated with arteriovenous malformations and who presented to our institute between 2000 and 2017 were identified. Patient demographics, aneurysm characteristics, interventions, and follow-up data were collected, compared, and analyzed. For the review, data including number of aneurysm treated, outcomes, follow-up, and occlusion rates were collected.

RESULTS

Mean age of the 31 identified patients was 57.4 ± 12.3 years; 19.4% were men. Mean aneurysm size was 5.1 ± 2.9 mm. Seven of 21 patients with unruptured aneurysms were managed conservatively. Ten patients (32.3%) presented with ruptured aneurysms (mean aneurysm size, 6.2 ± 3.2 mm). Treatment was successfully completed in 22 patients: 13-primary coiling, 7-stent-assisted coiling, and 2-microsurgical clipping. Complete angiographic aneurysm occlusion after primary treatments was achieved in 19 (86.4%) patients. The total complication rate among treated patients was 4.2% (1 of 24 treated aneurysms). No minor complications occurred. However, in 2 patients, coil embolization was attempted but aborted due to coil protrusion into the parent artery. Clinical and angiographic follow-up data were available for 26 observed or treated patients. Mean follow-up duration was 5.3 ± 4.5 years. Six articles met our review inclusion criteria and demonstrated similar mean treated aneurysm sizes ranging from 4.6-7.7 mm, and follow-up from these articles ranged from 15.3-50 months.

CONCLUSIONS

Endovascularly treated patients with ruptured and unruptured SCA aneurysms, of which most were <7 mm, had good clinical outcomes with minimal complications.

Predictive value of neurophysiological monitoring during posterior communicating artery aneurysm clipping for postoperative neurological deficits

Objective

This study aimed to evaluate the diagnostic effect of intraoperative neurophysiological monitoring in identifying intraoperative ischemic events and predicting postoperative neurological dysfunction during PCoA aneurysm clipping, as well as to explore the safe duration of intraoperative temporary clipping of the parent artery.

Methods

All 71 patients with PCoA aneurysm underwent craniotomy and aneurysm clipping. MEP and SSEP were used for monitoring during operation to evaluate the influence of MEP/SSEP changes on postoperative neurological function. Receiver operating characteristic (ROC) curve analysis was used to calculate optimal duration of intraoperative temporary clipping.

Results

Patients with intraoperative MEP/SSEP changes were more likely to develop short-term and long-term neurological deficits than those without MEP/SSEP changes (P < 0.05). From the ROC curve analysis, the safe time from the initiation of temporary clipping during the operation to the early warning of neurophysiological monitoring was 4.5 min (AUC = 0.735, 95%CI 0.5558-0.912). Taking 4.5 min as the dividing line, the incidence of short-term and long-term neurological dysfunction in patients with temporary clipping >4.5 min was significantly higher than that in patients with temporary clipping ≤4.5 min (P = 0.015, P = 0.018).

Conclusion

Intraoperative MEP/SSEP changes are significantly associated with postoperative neurological dysfunction in patients with PCoA aneurysms. The optimal duration of temporary clipping of the parent artery during posterior communicating aneurysm clipping was 4.5 min under neurophysiological monitoring.

Endovascular treatment of challenging aneurysms with FRED Jr flow diverter stents: a single-center experience

PURPOSE

To analyze clinical safety and efficacy of flow re-direction endoluminal device (FRED) Jr flow diverter for treatment of unruptured, ruptured, or recanalyzed aneurysms.

MATERIALS AND METHODS

Between October 2019 and February 2022, 25 patients with 31 aneurysms treated with FRED Jr were included in the study. Clinical and radiological records, procedural details, and follow-up outcomes were retrospectively evaluated. Eighteen (72%) patients were female. Median age was 48.8 (age range 9-85). Mean follow-up was 21 months (6-28 months). Location of the aneurysms were as follows; 13 in middle cerebral artery (MCA), 7 in anterior cerebral artery (ACA), 4 in posterior cerebral artery (PCA), 3 in true posterior communicating artery (PCom), 2 in anterior communicating artery (ACom), 1 in superior cerebellar artery (SCA), 1 in true ophthalmic artery. Five patients (20%) presented with acute subarachnoid hemorrhage (aSAH).

RESULTS

In all procedures, FRED Jr was successfully deployed. Three true Pcom aneurysms and a true ophthalmic aneurysm were treated with FRED Jr. Three patients with two adjacent aneurysms were treated with a single FRED Jr. In two (8%) patients in-stent thrombosis occurred intraoperatively, they were treated with iv tirofiban and thrombectomy without any sequelae. Post-discharge 2 weeks later, intraparenchymal hemorrhage occurred in a patient. He was treated with surgical drainage, the clinical course was modified Rankin score (mRS) 2. Digital subtraction angiography (DSA) was performed on 16 (64%) patients with 21 (67%) aneurysms. Near complete-complete occlusion (O'Kelly-Morata grading scale (OKM C-D) was documented in 15/16 (93.7%) patients, 20/21 (95.2%) aneurysms. In nine (36%) patients, no residual filling was observed in the magnetic resonance angiography (MRA). Good clinical outcome (mRS 0-1) was achieved in 24/25 (96%) of patients.

CONCLUSION

Endovascular treatment of small cerebral aneurysms with FRED Jr is safe and effective even in complex and challenging morphologies allowing high rates of aneurysm occlusion with low periprocedural complications. Our cohort, consisting of a rate 20% acute ruptured aneurysms, is the major additive data to the published literature.

Morphological evaluation of the risk of posterior communicating artery aneurysm rupture: a mirror aneurysm model

OBJECTIVE

The aim of this study was to use morphological parameters of mirror posterior communicating artery (PCoA) aneurysms to evaluate aneurysm rupture risk.

METHODS

The morphological parameters of 45 pairs of ruptured mirror PCoA aneurysms were analyzed. Conditional univariate and multivariate logistic regression of the following paired morphological parameters was performed: aneurysm with a daughter sac, aneurysm height, aneurysm width, neck width, internal carotid artery diameter, PCoA diameter, flow angle, PCoA angle, aspect ratio, bottleneck factor, size ratio, height/width ratio, fetal posterior cerebral artery, and aneurysm with height > width. A scoring system was established according to the odds ratios (ORs). The receiver operating characteristic was used to test the prediction accuracy of this scoring system in the authors' database of 523 PCoA aneurysms and the threshold value was used to define higher risk.

RESULTS

Aneurysm width (OR 1.676, p = 0.014), aneurysm with daughter sac (OR 7.775, p = 0.016), and aneurysm with height > width (OR 9.067, p = 0.012) were independent risk factors for rupture. The scoring system consisted of aneurysm width (1 point per mm), aneurysm with a daughter sac (5 points), and aneurysm with height > width (5 points). The area under the curve (AUC) of the scoring system was 0.842, and its threshold value was 7.97. A score ≥ 8 points was defined as higher risk. The AUC using this definition was 0.802.

CONCLUSIONS

Aneurysm width, aneurysms with height > width, and aneurysms with a daughter sac were independent risk factors for PCoA aneurysm rupture. The scoring system devised in this study accurately predicts rupture risk.

Selection bias in patients proposed for neurosurgical versus endovascular treatment of aneurysms of the posterior communicating artery

BACKGROUND

Microsurgical clipping and endovascular coiling are viable treatment options for posterior communicating artery (PComA) aneurysms, but there are still major limitations to evidence-based decisions regarding standard-of-care treatment. In this study, we aimed at assessing potential selection biases that may influence our ability to extract conclusions about the comparative effectiveness or efficacy of the aneurysm treatment.

OBJECTIVE

To study the patient/aneurysm characteristics as possible biases in the option for endovascular or neurosurgical treatment of PComA aneurysms.

METHODS

A single-center, retrospective cohort study was performed, including all patients with treated PComA aneurysms with neurosurgical clipping or endovascular coiling between January 2010 and January 2021. Clinical and morphological data were collected from electronic records, and statistical analysis was performed.

RESULTS

A total of 64 patients was eligible for inclusion; 24 (37.5%) patients were proposed for neurosurgical treatment, while 40 (62.5%) for endovascular treatment; 10 patients (25%) crossed over to the clipping group whereas none crossed over to the coiling side. Actual treatment analysis showed significantly higher diameters of mother vessel (t-test, p = 0.034) and aneurysm neck (Mann-Whitney, p = 0.029) in the clipping group and higher aspect and dome-to-neck ratios in the endovascular group (Mann-Whitney, p = 0.008). A significantly higher vasospasm frequency was found in the clipping group but only in the intention-to-treat analysis (Chi-square, p = 0.032).

CONCLUSION

Significant morphological differences between effective endovascular and surgical groups and differences in intention-to-treat analysis may limit the validity of a direct comparison between treatment options and suggest the presence of a possible selection bias.

Cerebral ischemia after treatment of posterior communicating artery aneurysms: clipping versus coiling

Objection

This study aimed to compare the incidence of cerebral ischemia and outcomes between surgical clipping and endovascular coiling in patients with posterior communicating artery (PCoA) aneurysms.

Methods

Clinical and imaging data of patients with at least one PCoA aneurysm who underwent surgical clipping or endovascular coiling in our institution from January 2017 to December 2019 were analyzed.

Results

Three hundred sixty-three aneurysms in 353 patients were included for analysis, 257 in the clipping group, and 106 in the coiling group. The groups did not differ in terms of baseline characteristics. The incidence of postoperative cerebral ischemia (23.35% vs. 11.32%, p = 0.029) was higher in the clipping group. The proportion of patients with a modified Rankin Scale score ≥ 2 was significantly higher in the clipping group at discharge (35.80% vs. 15.09%; p < 0.05) but not six months after discharge (15.56% vs. 8.49%; p > 0.05). In the clipping group, the mean age was significantly higher in patients who developed cerebral ischemia than in those who did not. In the coiling group, modified Fisher grade and incidence of fetal PCoA were significantly higher in patients who developed ischemia.

Conclusion

The incidence of postoperative cerebral ischemia was higher after PCoA aneurysm clipping than after coiling. The causes and characteristics of postoperative cerebral ischemia after PCoA clipping and coiling are different; therefore, treatment should be selected accordingly.

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.

Case report and literature review: Resection of retroinfundibular craniopharyngioma via endoscopic far-lateral supracerebellar infratentorial approach

Introduction

The management of retroinfundibular craniopharyngioma (CP) remains the ultimate challenge for both transsphenoidal and open transcranial surgery because of their anatomical location and proximity to vital neurovascular structures. In this report, we aim to describe the technique and feasibility of a novel approach, the purely endoscopic far-lateral supracerebellar infratentorial approach (EF-SCITA), for resection of retroinfundibular CP.

Case description

A 63-year-old women presented with progressive visual disturbance, polyuria, and spiritlessness of a 3-month duration. Imaging studies revealed a typical retroinfundibular CP containing solid and cystic components with calcification, which extended inferiorly in front of the brainstem and upward into the third ventricle. The EF-SCITA approach was attempted for resection of the tumor. During surgery, lateral prone positioning with upper flexion of the head and early CSF release allowed for download retraction of the cerebellum. This, in combination with tentorium incision, created a working corridor toward retrosellar and suprasellar spaces. This approach required working between neurovascular structures in the crural cistern, with tumor removal permitted in supra-oculomotor and infra-oculomotor spaces. After aspiration of the fluid contents through the supra-oculomotor triangle, the solid lesion was found tightly adhering to the distal part of the pituitary stalk, and subtotal resection was achieved for maintaining the integrity of pituitary function. In the immediate postoperative period, the patients exhibited oculomotor paralysis and was discharged with hormonal replacement therapy three weeks after operation. At her three-month follow-up appointment, she reported obvious vision improvement. Physical examinations showed partial alleviation of oculomotor paralysis. Pathological analyses confirmed the diagnosis of papillary CP.

Discussion

The purely EF-SCITA approach combines the advantages of both the posterolateral approach and endoscopic technique, which offers access to retrosellar and suprasellar spaces with seemingly low risks of postoperative morbidity. It would be a safe and effective alternative for the treatment of retroinfundibular CP, especially those with lateral extension to the temporal lobe or posterolateral extension to the petroclival region. Further observational studies in a larger cohort are urgently needed to assess the long-term efficacy of this minimal access approach.

FRED flow diversion with LVIS protection of large posterior communicating artery aneurysm: the "FRELVIS" technique

Treatment of wide-necked posterior communicating artery (PCoA) aneurysms is extremely challenging, especially in fetal posterior cerebral artery (PCA) configurations. This technical video demonstrates the nuances of an innovative use of flow diversion to treat a recurrent wide-necked PCoA aneurysm. This middle-aged patient presented with recurrence of a previously ruptured, coil-embolized PCoA aneurysm. Initial attempts at Comaneci-assisted coiling were unsuccessful because the coil herniated into the middle cerebral artery (MCA). Therefore, a low-profile visualized intraluminal support (LVIS) was placed in the fetal PCA across the aneurysm ostium and a flow diverter was placed in the internal carotid artery and MCA to constitute a Y-construct. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2262.

Efficacy and long-term results of endovascular embolization and surgical clipping for posterior communicating artery unruptured aneurysms complicated with oculomotor nerve palsy

to investigate the efficacy and long-term outcomes of endovascular embolization and surgical clipping for patients with posterior communicating artery unruptured aneurysms (PcomAs) concomitant with oculomotor nerve palsy (ONP). No significant (P > .05) difference existed in the age, gender, proportion of complete ONP, and size of eye fissure and pupil before treatment between 2 groups. After compared with before treatment, the eye fissure was widened significantly (P < .05) and the pupil narrowed significantly (P < .05), but no significant (P > .05) differences existed between the 2 groups. Complete ONP recovery was observed in 32 (80%) patients in the embolization group and 31 (77.5%) in the microsurgical group, partial ONP recovery occurred in 6 (15%) in the embolization group and 8 (20%) in the microsurgical group. The recovery rate was 95% in the embolization group and 97.5% in the microsurgical group, with no significant (P > .05) difference between 2 groups. The recovery rate of the ONP was significantly (P < .01) greater in the microsurgical group than that in the embolization group at follow-up of 1 month, 3 months, six and 12 months, respectively. At 18 months, the ONP recovery rate was not significantly different between 2 groups (95% vs 97.5%) Surgical clipping may have a faster effect on the recovery of oculomotor nerve palsy than endovascular embolization for patients with posterior communicating artery unruptured aneurysms complicated with oculomotor nerve palsy, but both approaches may result in a similar effect on the nerve recovery in the long run.Eighty patients treated with endovascular embolization or surgical clipping were retrospectively enrolled into the endovascular embolization group or surgical clipping and analyzed.

Treatment of large and giant posterior communicating artery aneurysms with the Surpass streamline flow diverter: results from the SCENT trial

BACKGROUND

The Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the communicating artery segment.

METHODS

The Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) trial is an international, multicenter, prospective, non-randomized trial comparing the outcomes of Surpass flow diverter treatment with historic control designed to evaluate the effectiveness and safety of Surpass for the treatment of wide neck (≥4 mm) large or giant intracranial aneurysms ≥10 mm. The primary effectiveness endpoint is the percentage of subjects with 100% aneurysm occlusion without significant stenosis of the parent artery and without retreatment of the target aneurysm at 12 months. The primary safety endpoint is the percentage of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. We report the effectiveness and safety of flow diversion in the subgroup of posterior communicating artery (PComA) aneurysms.

RESULTS

Of the 180 patients treated, 38 harbored a PComA aneurysm. Mean aneurysm size was 12.2 mm and mean neck width was 4.8 mm. The mean number of Surpass devices used was 1.1 per procedure, with 94.7% of aneurysms treated with one flow diverter. The 12 month primary effectiveness rate was 73.7% (28/38). At 36 months, 68.4% (26/38) of aneurysms remained completely occluded. The 12 month major ipsilateral stroke or neurological death rate was 10.5%. No patients with PComA occlusion after flow diverter placement (54.5%) had clinical sequelae.

CONCLUSIONS

SCENT demonstrated acceptable 12 month effectiveness of flow diversion in PComA aneurysms. Despite associated PComA occlusions in many cases, arterial occlusions were clinically silent.

TRIAL REGISTRATION NUMBER

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT01716117.

Initial experience in the microsurgical treatment of ruptured brain aneurysms in the endovascular era: characteristics and safety of the learning curve in the first 300 consecutively treated patients

PURPOSE

Currently, there is an increasing tendency to refer only complex aneurysms for microsurgery. The formation of new neurosurgeons dedicated to open vascular neurosurgery becomes challenging in a situation in which complex aneurysms must be dealt with early in the career, raising questions about the safety of the learning curve.

METHODS

We analyzed the characteristics and surgical results of the first 300 consecutively treated patients after subarachnoid hemorrhage by a single neurosurgeon. The incidence of surgical complications and clinical outcomes during the learning curve were analyzed, looking for critical periods regarding patient safety. Microsurgical operative times were also studied.

RESULTS

A high frequency of wide-necked aneurysms was observed (70.3%), and, as a result, large (> 10 mm), MCA and paraclinoid aneurysms were overrepresented. A statistically significant correlation between surgical experience and clinical outcomes was observed, with progressive surgical experience resulting in a lower incidence of unfavorable outcomes. We also observed a higher frequency of major surgical complications, unfavorable clinical outcomes, and lower complete occlusion rates among the first 40 patients. Microsurgical operative times progressively and significantly decreased during the learning curve.

CONCLUSIONS

We observed a high prevalence of wide-necked aneurysms. Young neurosurgeons must be trained and prepared to deal with these aneurysms early in their careers. Although we observed a decrease in unfavorable results with cumulative surgical experience, the first 40 cases were associated with higher rates of major surgical complications, worse clinical outcomes, and lower complete occlusion rates, indicating that this period may be more critical to patient safety.

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.

Fetal posterior cerebral artery configurations in an ischemic stroke versus an unselected hospital population

BACKGROUND

Few MRA-based studies have systematically evaluated the prevalence and laterality of a fetal configuration of the posterior cerebral artery (FTP) in ischemic stroke populations versus other populations. This common variant is important in the setting of acute stroke and secondary prevention decisions.

OBJECTIVE

To determine the prevalence and laterality of FTP configurations in MRI-DWI verified acute ischemic stroke patients investigated with MRA, and compare the findings with an unselected hospital population investigated with computed tomography angiography (CTA). We also evaluated the association of FTP with posterior cerebral artery (PCA) territory infarctions.

METHODS

We reviewed the MRAs of 1407 ischemic stroke patients with acute lesions on MRI-DWI sequences and 546 consecutive CTAs of patients investigated on any indication in a tertiary hospital. The MRA and CTA assessments were made by neuroradiologists blinded to original reports on stroke location and vessel anatomy.

RESULTS

The prevalence of any FTP was similar in ischemic stroke patients (31%) and unselected patients (32%). Unilateral FTP was significantly more frequent on the right than on the left side in both groups (15% right vs. 8% left). The presence of FTP ipsilateral to stroke side was not associated with involvement of the PCA territory versus no FTP on the stroke side.

CONCLUSIONS

FTP is present in approximately 30% of ischemic stroke patients and unselected hospital populations and was detected significantly more frequently on the right versus left side in both groups. PCA territory infarction was not associated with the presence of ipsilateral FTP.

Procedural complications in patients undergoing microsurgical treatment of unruptured intracranial aneurysms: a single-center experience with 1923 aneurysms

BACKGROUND

With the growing use of endovascular therapy (EVT) to manage unruptured intracranial aneurysms (IAs), detailed information regarding periprocedural complication rates of microsurgical clipping and EVT becomes increasingly important in determining the optimal treatment for individual cases. We report the complication rates associated with open microsurgery in a large series of unruptured IAs and highlight the importance of maintaining surgical skill in the EVT era.

METHODS

We reviewed all cases of unruptured IAs treated with open microsurgery by a single neurosurgeon between July 1997 and June 2019. We analyzed surgical complications, deaths, and patient-reported outcomes.

RESULTS

A total of 1923 unruptured IAs in 1750 patients (mean age 44 [range: 6-84], 62.0% [1085/1750] female) were treated surgically during the study period. Of the aneurysms treated, 84.9% (1632/1923) were small, 11.1% (213/1923) were large, and 4.1% (78/1923) were giant. Aneurysm locations included the middle cerebral artery (44.2% [850/1923]), internal carotid artery (29.1% [560/1923]), anterior cerebral artery (21.0% [404/1923]), and vertebrobasilar system (5.7% [109/1923]). The overall mortality rate was 0.3% (5/1750). Surgical complications occurred in 7.4% (129/1750) of patients, but only 0.4% (7/1750) experienced permanent disability. The majority of patients were able to return to their preoperative lifestyles with no modifications (95.9% [1678/1750]).

CONCLUSIONS

At a high-volume, multidisciplinary center, open microsurgery in carefully selected patients with unruptured IAs yields favorable clinical outcomes with low complication rates. The improvement of EVT techniques and the ability to refer cases for EVT when a high complication rate with open microsurgery was expected have contributed to an overall decrease in surgical complication rates. These results may serve as a useful point of reference for physicians involved in treatment decision-making for patients with unruptured IAs.

Hemodynamic and Morphological Parameters of Ruptured Mirror Posterior Communicating Artery Aneurysms

Objective: Morphological and hemodynamic parameters might predict rupture of intracranial aneurysms (IAs). A practical model for the study is patients with ruptured mirror IAs in which one is ruptured and the other is unruptured. Although there have been analyses of the morphology and hemodynamics of ruptured mirror posterior communicating artery aneurysms (PComAAs), the sample sizes in these studies were small and only considered hemodynamics or morphological characters. Therefore, this study aimed to investigate the morphological and hemodynamic parameters associated with ruptured mirror PComAAs. Methods: We considered 72 patients with ruptured mirror PComAAs using computational fluid dynamics (CFDs). Ruptured mirror PComAAs were divided into ruptured and unruptured groups. Fourteen morphological and eight hemodynamic parameters were calculated and compared. Significant parameters were analyzed by the multivariate logistic regression to identify independent risk factors. Receiver operating characteristic (ROC) analysis was performed, and the area under the ROC curve (AUC) was calculated for all independent risk factors to determine the predictability and identify the optimal threshold. Results: Four hemodynamic and three morphological parameters were significantly different between ruptured and unruptured groups: normalized wall shear stress (NWSS), mean WSS, low wall shear WSS area (LSA%), size, aspect ratio (AR), size ratio (SR), and inflow angle (IA). Multivariate logistic regression analysis showed that AR, SR, NWSS, mean WSS, and LSA% were all independent factors significantly associated with PComAAs rupture. The ROC analysis for independent risk factors indicated that AR (0.751), NWSS (0.755), mean WSS (0.69), and LSA (0.778) had merely acceptable AUC values. Only SR (0.803) had a high acceptable AUC value. The threshold value of SR was 1.96. Conclusions: SR (>1.96) was the most significant parameter associated with IA rupture, whereas AR, NWSS, mean WSS, and LSA independently characterized the status of IA rupture.

λ stenting: a novel technique for posterior communicating artery aneurysms with fetal-type posterior communicating artery originating from the aneurysm dome

Purpose

Endovascular treatment of posterior communicating artery aneurysms with fetal-type posterior communicating artery originating from the aneurysm dome is often challenging because, with conventional techniques, dense packing of aneurysms for posterior communicating artery preservation is difficult; moreover, flow-diversion devices are reportedly less effective. Herein, we describe a novel method called the λ stenting technique that involves deploying stents into the internal carotid artery and posterior communicating artery.

Methods

Between January 2018 and September 2020, the λ stenting technique was performed to treat eight consecutive cases of aneurysms. All target aneurysms had a wide neck (dome/neck ratio < 2), a fetal-type posterior communicating artery with hypoplastic P1, and a posterior communicating artery originating from the aneurysm dome. The origin of the posterior communicating artery from the aneurysm, relative to the internal carotid artery, was steep (< 90°: V shape).

Results

The maximum aneurysm size was 8.0 ± 1.9 mm (6–12 mm). The average packing density (excluding one regrowth case) was 32.7 ± 4.2% (26.8–39.1%). Initial occlusion was complete occlusion in 6 (75.0%) patients and neck remnants in 2 (25.0%) patients. Follow-up angiography was performed at 18.4 ± 11.6 months (3–38 months). There were no perioperative complications or reinterventions required during the study period.

Conclusion

The λ stenting technique enabled dense coil packing and preservation of the posterior communicating artery. This technique enabled safe and stable coil embolization. Thus, it could become an alternative treatment option for this sub-type of intracranial aneurysms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00234-021-02775-y.

Clipping versus coiling for the treatment of oculomotor nerve palsy induced by posterior communicating artery aneurysms: A comparison of effectiveness

BACKGROUND

A long debate has been going on in the clinical effectiveness to determine whether surgical clipping or coiling more favorable for oculomotor nerve palsy (ONP) caused by PcomAA. We aimed to perform a study, focusing on the effectiveness of ONP induced by PcomAA after treatment of surgical clipping and endovascular coiling.

METHOD

Potential studies were searched on PubMed, EMBASE, Web of Science, and Cochrane Library from database inception to February 2021, and STATA version 12.0 was exerted to process the pooled data.

RESULTS

A total of 16 articles are included in the study, hailing from the United States, South Korea, the United Kingdom, France, Germany, Korea, China, Japan, Britain, and Singapore. The results showed that the clipping group was related to a higher incidence of complete ONP recovery at follow-up (OR = 5.808, 95% CI 2.87 to 11.76, p < 0.001), the lower rates of partial ONP recovery (OR = 0.264, 95% CI 0.173 to 0.402, p < .001) and no improvement of ONP at follow-up (RD = -0.149, 95% CI -0.247 to -0.051, p = .003). In the subgroup of complete ONP recovery based on the condition of patients, clipping was associated with a higher incidence of complete ONP recovery in patients with the incomplete initial ONP (OR = 3.579, p = .020) and ruptured aneurysm (OR = 5.38, p = .020). Regarding the subgroup of complete ONP recovery based on the quality of studies, similar results also appeared.

CONCLUSION

Surgical clipping was more favorable to the recovery from ONP caused by PcomAA endovascular coiling due to a higher rate of recovery and recovery degree of ONP. Besides that, more evidence-based performance is necessary to supplement this opinion.

Pipeline embolization of ruptured, previously coiled cerebral aneurysms: Case series and considerations for management

PURPOSE:

Aneurysmal recurrence represents a significant drawback of endovascular coiling, particularly in aneurysms that have previously ruptured. Given the high recurrence rate of coiled aneurysms and particularly the risk of posttreatment rupture in previously ruptured aneurysms that have been treated by coiling, the question of how best to treat ruptured aneurysms that recur postcoiling remains.

MATERIALS AND METHODS:

We conducted a retrospective analysis of twenty patients who underwent pipeline embolization of previously ruptured, coiled cerebral aneurysms.

RESULTS:

Pipeline embolization device (PED) treatment resulted in complete aneurysmal occlusion in 10 patients (62.5%) at first angiographic follow-up, and 11 patients (68.75%) at last follow-up. No PED-related complications were encountered and there were no peri-procedural or postprocedural hemorrhages, or symptomatic ischemic events following flow diversion.

CONCLUSIONS:

PED as a second-line treatment is a safe and effective modality for achieving aneurysmal occlusion in recurrent, previously ruptured, primarily coiled aneurysms. Additionally, a staged coil-to-PED approach may be considered for the management of acutely ruptured aneurysms to achieve aneurysmal obliteration in an effort to mitigate recurrence, and reduce the amount of postprocedural studies.

Risk Factors for the Recurrence of Posterior Communicating Artery Aneurysm: The Significance of Fetal-Type Posterior Cerebral artery

OBJECTIVES

The purpose of this study was to investigate the risk factors associated with recurrence of posterior communicating artery aneurysms after treatment and to evaluate the significance of fetal-type posterior cerebral artery as an independent risk factor for recurrence of posterior communicating artery aneurysms.

MATERIALS AND METHODS

The clinical and radiological findings of 220 posterior communicating artery aneurysms treated between January 2009 and December 2016 in a single tertiary institute were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the association between clinical and radiological variables and recurrence.

RESULTS

Of 220 posterior communicating artery aneurysms, 148 aneurysms were unruptured and 82 aneurysms were treated with surgery. Forty-six out of 220 aneurysms (20.9%) were associated with fetal-type posterior cerebral artery. Overall recurrence rate was 19% (42 out of 220 aneurysms) during mean 54.6 ± 29.8 months follow-up. Multivariate logistic regression analysis showed that size (OR=1.238; 95% CI, 1.087-1.409, p = 0.001), ruptured status (OR=2.699; 95% CI, 1.179-6.117, p = 0.019), endovascular treatment (OR=3.803; 95% CI, 1.330-10.875, p = 0.013), incomplete occlusion (OR=4.699; 95% CI, 1.999-11.048, p = <0.001) and fetal-type posterior cerebral artery (OR=3.533; 95% CI, 1.373-9.089, p = 0.009) were significantly associated with recurrence after treatment.

CONCLUSIONS

The results demonstrated that fetal-type posterior cerebral artery may be an independent risk factor for the recurrence of posterior communicating artery aneurysms. Therefore, fetal-type posterior cerebral artery can be considered as an important risk factor for the recurrence of posterior communicating artery aneurysms, along with other known risk factors such as size, ruptured status, endovascular treatment, and incomplete occlusion.

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.

Geometric variations associated with posterior communicating artery aneurysms

BACKGROUND

Hemodynamic stress, conditioned by the morphology of the surrounding vasculature, plays an important role in aneurysm formation. Our goal was to identify image-based location-specific parameters that are associated with posterior communicating artery (PCoA) aneurysms.

METHODS

Three-dimensional morphological parameters obtained from CT angiography or digital subtraction angiography from 187 patients with unilateral PCoA aneurysms, diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016, were evaluated. In order to control for genetic and clinical risk factors, we chose the contralateral unaffected PCoA as a control group. We examined diameters and angles of the surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with small aneurysms (≤5 mm) only and an unmatched analysis of 432 PCoA aneurysms and 197 control patients without PCoA aneurysms were also performed.

RESULTS

In a multivariable conditional logistic regression model we showed that smaller diameter size ratio (OR 1.45×10^-5, 95% CI 1.12×10^-7 to 1.88×10^-3) and larger daughter-daughter angle (OR 1.04, 95% CI 1.02 to 1.07) were significantly associated with PCoA aneurysm presence after correcting for other variables. In subgroup analyses of small aneurysms (≤5 mm) and in an unmatched analysis the significance and direction of these results were preserved.

CONCLUSIONS

Larger daughter-daughter angles and smaller diameter size ratio are significantly associated with the presence of PCoA aneurysms. These simple parameters can be utilized to guide the risk assessment for the formation of PCoA aneurysms in high risk patients.

Posterior Cerebral Circulation Stroke Secondary to Foetal Origin of Posterior Communicating Artery: An Indication for Carotid Endarterectomy

Introduction

Posterior cerebral circulation strokes are most commonly caused by posterior vasculature in situ thrombosis, cardiac emboli, or arterial dissection. However, the foetal origin of the posterior communicating artery is an anatomical variant of the cerebral circulation that results in communication between the internal carotid and posterior cerebral circulation. Therefore, rarely this can result in posterior cerebral territory infarction from internal carotid artery thrombo-embolism. This is the report of a case in which a patient suffered posterior circulation stroke secondary to this anatomical variation of the circle of Willis.

Report

A 71 year old male patient was admitted to the stroke team with seizures, headache, and confusion. Examination revealed a left sided homonymous hemianopia. Diffusion weighted magnetic resonance imaging (MRI) of the brain 36 hours into his admission revealed an acute right posterior circulation infarct with extensive haemorrhagic transformation. Duplex ultrasound three days later revealed a heavily calcified right internal carotid artery mixed echogenicity plaque with 80%-90% stenosis. Subsequent computed tomography angiography showed a large right foetal variant posterior communicating artery. Following improvement in functional status, the patient underwent uneventful carotid endarterectomy to reduce risk of future stroke.

Discussion

In patients presenting with posterior circulation infarction, clinicians should consider embolism from an atheromatous internal carotid artery via the variant foetal origin of posterior communicating artery. If detected, consideration should be given to undertaking carotid endarterectomy to reduce future stroke risk if no other source is detected.

Morphometric Comparison of the Pterional Trans-Sylvian and the Pretemporal Trans-Clinoidal Approaches to the Posterior Communicating Artery

BACKGROUND

Posterior communicating (Pcom) aneurysms in the modern era have tended toward increased complexity and technical difficulties. The pretemporal approach is a valuable extension to the pterional approach for basilar apex aneurysms, but its advantages for Pcom aneurysms have not been previously elucidated.

OBJECTIVE

To quantify characteristics of the pretemporal approach to the Pcom.

METHODS

We dissected 6 cadaveric heads (12 sides) with a pretemporal transclinoidal approach and measured the following variables: (1) exposed length of internal carotid artery (ICA) proximal to the Pcom artery; (2) exposed circumference of ICA at the origin of Pcom; (3) deep working area between the optic nerve and tentorium/oculomotor nerve; (4) superficial working area; (5) exposure depth; and (6) the frontotemporal (superior posterolateral) and (7) orbito-sphenoidal (inferior anterolateral) angles of exposure.

RESULTS

Compared with pterional craniotomy, the pretemporal transclinoidal approach increased the exposed length of the proximal ICA from 3.3 to 11.7 mm (P = .0001) and its circumference from 5.1 to 7.8 mm (P = .0003), allowing a 210° view of the ICA (vs 137.9°). The deep and superficial working areas also significantly widened from 53.7 to 92.4 mm2 (P = .0048) and 252.8 to 418.2 mm2 (P = .0001), respectively; the depth of the exposure was equivalent. The frontotemporal and spheno-Sylvian angles increased by 17° (P = .0006) and 10° (P = .0037), respectively.

CONCLUSION

The pretemporal approach can be useful for complex Pcom aneurysms by providing easier proximal control, wider working space, improved aneurysm visualization, and more versatile clipping angles. Enhanced exposure results in a potentially higher rate of complete aneurysm obliteration and complication avoidance.

Comparison of surgical clipping and endovascular coiling in the treatment of oculomotor nerve palsy caused by posterior communicating artery aneurysm

Oculomotor nerve palsy (ONP) caused by posterior communicating aneurysm (PcomAA) is mainly treated by surgical clipping or endovascular coiling. However, there are still some controversies about which treatment method could provide the more beneficial prognosis. This study aimed to compare ONP recovery rate between surgical clipping and endovascular coiling in patients diagnosed as PcomAA combined with ONP, and explore the potential risk factors of ONP recovery.The clinical data of 152 patients with ONP caused by PcomAA were retrospectively analyzed. Diameter of aneurysm, different treatment methods (surgical clipping or endovascular coiling), subarachnoid hemorrhage (SAH), degree of preoperative ONP, time from ONP onset to treatment, as well as degree of ONP symptom recovery were collected from medical records. All patients were followed up for at least 1 year.One hundred twelve patients underwent surgical clipping and 40 patients received endovascular coiling. There were no significant differences in age, gender, aneurysm diameter, hypertension, dyslipidemia, time from ONP symptom onset to treatment, SAH, and preoperative ONP degree between the 2 groups (all P > .05). Time to complete or partial recovery was 86.7 ± 35.7 days for patients receiving surgical clipping and 132.6 ± 37.5 days for patients receiving endovascular coiling, respectively (Log rank test, P < .001). The recovery rate was 94.6% in the surgical clipping group and 65.0% in the endovascular coiling group. The difference between the two groups was statistically significant (P < .001). Postoperative ONP recovery in the surgical clipping group was significantly superior to that of patients in the endovascular coiling group (HR, 2.625; 95% CI: 1.423-4.841; P = .002). Time from ONP symptom onset to treatment exerted the obvious effect on the ONP prognosis (HR, 0.572; 95% CI: 0.384-0.852; P = .006). In addition, the ONP recovery in patients with SAH before surgery was also independently associated with ONP prognosis (HR, 1.276; 95% CI, 1.043-1.562; P = .018). There was no treatment-related death in either group, and postoperative complications were within the manageable range.The recovery rate and recovery degree of ONP after surgical clipping was significantly better than that of endovascular coiling in PcomAA patients combined with ONP. The postoperative ONP recovery was associated with preoperative spontaneous SAH and time from ONP onset to treatment.

Recovery of posterior communicating artery aneurysm induced oculomotor nerve palsy: a comparison between surgical clipping and endovascular embolization

BACKGROUND

Oculomotor nerve palsy (ONP) is a common symptom of posterior communicating artery aneurysm (PcomAA) that can lead to impaired eye movement and pupil dilation. Currently, surgical clipping and endovascular embolization are the two most popular treatment methods for PcomAA-induced ONP; however, the recovery outcome between the two methods remains to be elucidated.

METHODS

In the present study, we thoroughly compared the pretreatment factors and recovery outcome of the two treatments on 70 patients with PcomAA-induced ONP. The patients were separated into two groups based on the treatment that was received. Pretreatment factors, including age, sex, time period between ONP onset and treatment, ONP type, aneurysm diameter, status of subarachnoid hemorrhage and aneurysm rupture were recorded for each individual patient. Recovery outcome of the patients was assessed over a 12-month period.

RESULTS

No significant differences were observed in any of the analyzed factors. Importantly, we revealed a significantly higher full recovery rate for the patients receiving the surgical clipping treatment than the ones that received the endovascular embolization treatment. In addition, we showed that patients' age was negatively correlated with the recovery extent in both treatment groups.

CONCLUSIONS

The outcome of our study suggests that surgical clipping might be a better option to treat PcomAA-induced ONP.

Comparación del tratamiento quirúrgico y endovascular de aneurismas del segmento comunicante posterior

Antecedentes:

Los aneurismas del segmento comunicante posterior representan aproximadamente 25% de todos los aneurismas intracraneales, y el 50% de los aneurismas de la arteria carótida interna. El objetivo fue evaluar la eficacia del tratamiento quirúrgico y endovascular en el manejo de aneurismas de esta localización.

Métodos:

Estudio comparativo retrospectivo. Se revisó las historias clínicas de pacientes con aneurisma del segmento comunicante posterior que ingresaron al departamento de Neurocirugía del Hospital Nacional Guillermo Almenara durante el periodo 2010–2017. Se comparó estancia hospitalaria, complicaciones, mortalidad y estado funcional a los 12 meses, en relación al tratamiento recibido, microquirúrgico o endovascular.

Resultados:

Se evaluaron 256 pacientes, 111 (43.36%) recibieron tratamiento quirúrgico, y 145 (56.64%) endovascular. En el caso de aneurismas rotos, el estado de independencia funcional fue alcanzado por 68 (66.7%) y 69 (70.4%) pacientes que recibieron tratamiento quirúrgico y endovascular, respectivamente (OR: 0.84, IC 95%: 0.46–1.53; P = 0.505). Se presentaron complicaciones neurológicas en 37 (36,3%) y 34 (34.7%) pacientes sometidos a tratamiento microquirúrgico y endovascular, respectivamente (OR: 1.07, IC 95%: 0.60–1.91; P = 0.912). La estancia hospitalaria promedio fue 19.55 ± 13.85 y 14.06 ± 14.97 días, para pacientes con tratamiento quirúrgico y endovascular, respectivamente (P < 0.008). La mortalidad fue 11.8% y 11.2%, con ligera predominancia en el grupo tratado quirúrgicamente (OR: 1.05, IC 95%: 0.44–2.52; P = 0.904).

Conclusión:

No existe diferencia significativa respecto al resultado funcional a los 12 meses, complicaciones y mortalidad entre ambos tipos de tratamiento en el caso de aneurismas rotos. Los pacientes sometidos a terapia endovascular tuvieron de forma significativa menor estancia hospitalaria.

Increased focal internal carotid artery angulation in patients with posterior communicating artery aneurysms

Background

Aneurysms at the posterior communicating artery (PCOM) origin represent the most common location on the internal carotid artery (ICA), and are associated with greater recurrence following endovascular treatment. We evaluate the association between ICA angulation in three-dimensional (3D) space and PCOM aneurysmal development, using high-resolution 3D rotational angiography (3DRA) studies.

Methods

3DRA datasets were evaluated in 70 patients with PCOM aneurysms, 31 non-aneurysmal contralateral, and 86 healthy controls (187 total). The local angle formed by upstream and downstream ICA segments at the PCOM origin, αICA@PCOM, was measured using 3DRA multiplanar reconstruction. Computational fluid dynamics (CFD) analysis was performed on parametric and patient-based models.

Results

αICA@PCOM was significantly larger in aneurysm-bearing ICA segments (68.14±11.91°) compared with non-aneurysmal contralateral (57.17±10.76°, p<0.001) and healthy controls (48.13±13.68°, p<0.001). A discriminant threshold αICA@PCOM value of 61° (87% specificity, 80% sensitivity) was established (area under the curve (AUC)=0.88). Ruptured PCOM aneurysms had a significantly larger αICA@PCOM compared to unruptured (72.65±15.16° vs 66.35±9.94°, p=0.04). In parametric and patient-based CFD analysis, a large αICA@PCOM induces high focal pressure at the PCOM origin, relatively low wall shear stress (WSS), and high proximal WSS spatial gradients (WSSG).

Conclusion

ICA angulation at PCOM origin is significantly higher in vessels harboring PCOM aneurysms compared with contralateral and healthy ICAs. This sharper bend in the ICA leads to high focal pressure at the aneurysm neck, low focal WSS and high proximal WSSG. These findings underline the importance of morphological ICA variations and the likelihood of PCOM aneurysm, an association which can inform clinical decisions and may serve in predictive analytics.

Surgical Management of Posterior Communicating Artery Aneurysms in the Presence of a Low-Coursing Internal Carotid Artery and Narrowed Retrocarotid Window

BACKGROUND

Anatomical variations of the course of the internal carotid artery (ICA) may complicate surgical clipping of posterior communicating artery (PCoA) aneurysms by narrowing the retrocarotid window. We evaluated the efficacy of the periclinoid surgical maneuvers for expanding the retrocarotid window and analyzed computed tomography angiography (CTA) data from patients with PCoA aneurysms to define parameters for low-coursing ICAs.

METHODS

Using cadaveric specimens, standard pterional craniotomies were fashioned and extradural or intradural periclinoid surgical maneuvers-cutting of the meningo-orbital band, anterior clinoidectomy, and cutting of the distal dural ring (DDR)-were performed, and their relative advantages for expanding the retrocarotid window were assessed. Additionally, preoperative CTA data from 24 patients with PCoA aneurysms used to calculate the angles of the ICA relative to the skull base.

RESULTS

Periclinoid maneuvers, especially the anterior clinoidectomy, provided additional exposure of the retrocarotid space. Cutting of the DDR allowed for partial mobilization of the ICA and widened the retrocarotid surgical window, enhancing maneuverability. The anterior clinoidectomy with cutting of the DDR allowed for enhanced exposure of the medial, middle, and posterolateral aspects of the retrocarotid space. Cutting the anterior petroclinoid fold and mobilizing cranial nerve III provided wide exposure of the lateral aspect of retrocarotid space.

CONCLUSION

When clipping PCoA aneurysms in the presence of normal-coursing ICAs (approximately ≥30° ICA angle), a standard pterional craniotomy with anterior clinoidectomy and cutting of the DDR allows for substantial expansion of the retrocarotid window.

Prediction of the difficulty of proximal vascular control using 3D-CTA for the surgical clipping of internal carotid artery-posterior communicating artery aneurysms

OBJECTIVE

During surgical clipping of internal carotid artery (ICA)-posterior communicating artery (PCoA) aneurysms, proximal vascular control (PVC) is difficult to achieve in some cases because of variations in the anatomy of this type of aneurysm and its parent arteries. The authors investigated morphometric features that may be predictive for the necessity of anterior clinoidectomy (ACL) or cervical ICA exposure for PVC.

METHODS

The authors retrospectively reviewed 65 patients with an ICA-PCoA aneurysm treated with clipping during the previous 3 years. The factors considered for assessing the difficulty of attaining PVC included the following: the maximum diameter of the aneurysm; the distance between the tip of the anterior clinoid process (ACP) and the proximal aneurysmal neck; the presence of calcification at the ophthalmic segment of the ICA; and the angles between the communicating segment of the ICA and the ophthalmic segment of the ICA and a line perpendicular to the cranial base, which reflect the tortuosity of the ICA. These parameters were measured based on preoperative CTA results.

RESULTS

In a total of 21 patients (32.3%), PVC was difficult to perform with the usual pterional approach. In 6 patients, temporary artery occlusions (TAOs) were difficult to achieve because of severe atherosclerotic wall changes in the ophthalmic segment of the ICA. For 15 patients, the ACPs overhanging the ophthalmic segment of the ICA obstructed the ability to secure a space for TAO. In the 21 patients with PVC difficulty, ACL alone, cervical ICA exposure alone, and both ACL and cervical ICA exposure were conducted in 6, 8, and 7 patients, respectively. Multivariate analysis with binary logistic regression revealed that the maximum diameter of the aneurysm (p = 0.041), the distance between the proximal neck of the aneurysm and the ACP tip (p = 0.002), and calcification of the ICA ophthalmic segment (p = 0.001) were significant predictive factors for difficulties with PVC. A receiver operating characteristic curve analysis revealed that a distance between the proximal aneurysmal neck and the ACP tip of ≤ 5.4 mm was the best cutoff value for predicting the difficulty of attaining PVC (area under the curve 0.800, sensitivity 80.0%, specificity 80.0%).

CONCLUSIONS

A short distance between the proximal aneurysmal neck and the ACP tip and the presence of calcification at the ophthalmic segment of the ICA on preoperative CTA are helpful for predicting the difficulty of achieving PVC.

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.

A Fetal-type Variant Posterior Communicating Artery and its Clinical Significance

The fetal posterior communicating artery is a well-established variant of the cerebral vasculature, occurring in 4-29% of the population. This variant can provide unique challenges in the identification and treatment of cerebrovascular disease or a cerebrovascular accident. Here we present a cadaveric case showing the presence of the fetal-type posterior communicating artery with a contralateral calcified internal carotid artery and discuss the importance of understanding this embryological variant. This case provides specific and unique clinical sequelae that require treatment to be initiated while understanding the various complications that may arise. 

Morphological and clinical risk factors for the rupture of posterior communicating artery aneurysms: significance of fetal-type posterior cerebral artery

BACKGROUND

Posterior communicating artery (PcomA) aneurysm can be classified into sidewall or bifurcation types based on the anatomical variation of fetal-type posterior cerebral artery (fPCA). The aims of this study were to investigate the significance of fPCA as an independent risk factor for the rupture of PcomA aneurysm and to evaluate other associated morphological and clinical risk factors.

METHODS

We retrospectively reviewed clinical and radiological findings of 255 patients with PcomA aneurysms, which were treated in a single tertiary institute between January 2009 and December 2016. Univariate and multivariate analyses were performed to evaluate the associations between morphological and clinical variables and rupture status. Subgroup analysis was also performed based on the aneurysms with and without fPCA.

RESULTS

Fifty-five out of 255 PcomA aneurysms (21.6%) were associated with fPCA. Multivariate logistic regression analysis showed that the superior direction of aneurysm dome (OR 9.106, p = 0.007), the presence of a bleb (OR 4.780, p < 0.001), a high aspect ratio (OR 1.878, p = 0.045), and fPCA (2.101, p = 0.040) were significantly associated with PcomA aneurysm rupture. In the fPCA group, only the presence of a bleb varied significantly between ruptured and unruptured PcomA aneurysms. However, in the non-fPCA group, larger aneurysms, the superior direction of dome, the presence of a bleb, and a high aspect and dome-to-neck ratio were significantly higher in the ruptured aneurysm group than in the unruptured aneurysm group.

CONCLUSIONS

The results demonstrate that fPCA may be an independent risk factor for rupture, especially together with the presence of a bleb.

Retrograde stenting through anterior communicating artery in coil embolization of the posterior communicating artery aneurysm: contralateral approach

During coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms, stent assistance is sometimes limited if PcomA is acutely angled at its origins from saccular neck. Herein, we present two instances where retrograde stenting was used for coil embolization of PcomA aneurysms. Both procedures involved a contralateral approach via anterior communicating artery (AcomA). To achieve this, the stent-delivery microcatheter was inserted retrograde from contralateral to ipsilateral internal carotid artery (ICA) across AcomA, arriving at ipsilateral PcomA. A separate microcatheter, passed through ipsilateral ICA, was then used to select the aneurysm sac for coil delivery. Coil embolization ultimately took place under protection of a horizontally placed stent extending from PcomA to terminal ICA. Each aneurysm was properly coiled and occluded, without procedural complications. This stenting technique is a reasonable option, offering a means of strategic coil embolization in wide-necked PcomA aneurysms and providing complete neck coverage through contralateral access.

Impact of age on cerebral aneurysm occlusion after flow diversion

The purpose of this study was to evaluate safety and efficacy of the pipeline embolization device (PED) in different patient age groups with unruptured intracranial aneurysms (UIA). All patients with UIA treated with the PED between 2011 and 2017 were included. Based on their age, patients were trichotomized to: young (≤45 years), middle-aged (46 to <65 years) and older (≥65 years) groups. Patient's vascular risk factors, presenting symptoms and mRS on admission were collected. Follow-up imaging was evaluated for presence/absence of aneurysm occlusion. Clinical outcome at discharge, 3-9 months and 12-18 months was also documented when available. A total of 260 patients harboring 307 aneurysms (young = 57, middle-age = 144 and older age group = 64). Most aneurysms were located in the anterior circulation (94.8%). Overall morbidity and mortality was 2.3% each (6/260). At 3-9 months near complete to complete aneurysm occlusion was 82.5% (47/57) in the young age group, 82.6% (100/121) in the middle age, and 70.2% (40/57) in the older age group. At 12-18-month, near complete to complete occlusion was 100% in the young age group (32/32), 91.4% (64/70) in the middle age, and 78.4% (29/37) in the older age group. After adjustment for potential confounders, older age patients less frequently achieved near complete to complete occlusion by 3 years than younger subjects (p = 0.009, HR 1.34 95%, CI 1.08-1.66). Our results indicate feasibility and safety of PED across different age groups. Further study is required to determine age-related factors relating to aneurysm occlusion after PED to improve outcome and patient counseling.

Aneurysms with persistent filling after failed treatment with the Pipeline embolization device

OBJECTIVE

The Pipeline embolization device (PED) has become a valuable tool in the treatment of cerebral aneurysms. Although failures with PED treatment have been reported, the characteristics and course of these aneurysms remain a topic of uncertainty.

METHODS

Electronic medical records and imaging studies were reviewed for all patients treated with the PED between July 2010 and March 2015 to identify characteristics of patients and aneurysms with residual filling after PED treatment.

RESULTS

Of 316 cases treated at a single institution, 281 patients had a long-term follow-up. A total of 52 (16.4%) aneurysms with residual filling were identified and constituted the study population. The mean patient age in this population was 58.8 years. The mean aneurysm size was 10.1 mm ± 7.15 mm. Twelve aneurysms were fusiform (23%). Of the aneurysms with residual filling, there were 20 carotid ophthalmic (CO) aneurysms (20% of all CO aneurysms treated), 10 other paraclinoid aneurysms (16.4% of all paraclinoid aneurysms), 7 posterior communicating artery (PCoA) aneurysms (21.9% of all PCoA aneurysms), 7 cavernous internal carotid artery (ICA) aneurysms (14.9% of all cavernous ICA aneurysms), 4 vertebrobasilar (VB) junction aneurysms (14.8% of all VB junction aneurysms), and 3 middle cerebral artery (MCA) aneurysms (25% of all MCA aneurysms). Eleven patients underwent placement of more than one PED (21.2%), with a mean number of devices of 1.28 per case. Eight of 12 aneurysms were previously treated with a stent (15.4%). Nineteen patients underwent re-treatment (36.5%); the 33 patients who did not undergo re-treatment (63.5%) were monitored by angiography or noninvasive imaging. In multivariate analysis, age older than 65 years (OR 2.65, 95% CI 1.33-5.28; p = 0.05), prior stent placement across the target aneurysm (OR 2.94, 95% CI 1.15-7.51; p = 0.02), aneurysm location in the distal anterior circulation (MCA, PCoA, and anterior choroidal artery: OR 2.72, 95% CI 1.19-6.18; p = 0.017), and longer follow-up duration (OR 1.06, 95% CI 1.03-1.09; p < 0.001) were associated with incomplete aneurysm occlusion.

CONCLUSIONS

While the PED can allow for treatment of large, broad-necked aneurysms with high efficacy, treatment failures do occur (16.4%). Aneurysm size, shape, and previous treatment may influence treatment outcome.