Long-term quality of life outcomes in patients undergoing microsurgical resection of vestibular schwannoma

Background

While previous studies have assessed patient reported quality of life (QOL) of various vestibular schwannoma (VS) treatment modalities, few studies have assessed QOL as related to the amount of residual tumor and need for retreatment in a large series of patients. Objective: To assess patient reported QOL outcomes following VS resection with a focus on extent of resection and retreatment.

Methods

A retrospective chart review was performed using single-center institutional data of adult patients who underwent VS resection by the senior authors between 1989-2018 at Loyola University Medical Center. The Penn Acoustic Neuroma Quality of Life (PANQOL) survey was sent to all patients via postal mail.

Results

Fifty-five percent of 367 total patients were female with a mean age of 61.6 years (SD 12.63). The mean period between surgery and PANQOL response was 11.4 years (IQR: 4.74-7.37). The median tumor size was 2 cm (IQR: 1.5-2.8). The mean total PANQOL score was 70 (SD 19). Patients who required retreatment reported lower overall scores (μdiff = -10.11, 95% CI: -19.48 to -0.74; p = 0.03) and face domain scores (μdiff = -20.34, 95% CI: -29.78 to -10.91; p < .001). There was no association between extent of resection and PANQOL scores in any domain.

Conclusion

In an analysis of 367 patients who underwent microsurgical resection of VS, extent of resection did not affect PANQOL scores in contrast to previous reports in the literature, while the need for retreatment and facial function had a significant impact on patient-reported outcomes.

Angulation of the dural venous sinuses of the posterior cranial fossa: Anatomical study with clinical and surgical applications

Cerebral vein and dural venous sinus thromboses (CVST) account for 0.5%-1% of all strokes. Some structural factors associated with a potentially higher risk for developing CVST have been described. However, angulation of the dural venous sinuses (DVS) has yet to be studied as a structural factor. The current study was performed because this variable could be related to alterations in venous flow, thus predisposing to a greater risk of CVST development. Additionally, such information could help shed light on venous sinus stenosis (VSS) at or near the transverse-sigmoid junction. The angulations formed in the different segments of the grooves of the transverse (TS), sigmoid (SS), and superior sagittal sinuses (SSS) were measured in 52 skulls (104 sides). The overall angulation of the TS groove was measured using two reference points. Other variables were examined, such as the communication pattern at the sinuses' confluence and the sinus grooves' lengths and widths. The patterns of communication between sides were compared statistically. The most typical communication pattern at the sinuses' confluence was a right-dominant TS groove (82.98%). The mean angulations of the entire left TS groove at two different points (A and B) were 46° and 43°. Those of the right TS groove were 44° and 45°. The median angulations of the left and right SSS-transverse sinus junction grooves were 127° and 124°. The mean angulations of the left and right TS-SSJsv grooves were 111° (range 82°-152°) and 103° (range 79°-130°). Differentiating normal and abnormal angulations of the DVSs of the posterior cranial fossa can help to explain why some patients are more susceptible to pathologies affecting the DVSs, such as CVST and VSS. Future application of these findings to patients with such pathologies is now necessary to extrapolate our results.

A new era in the treatment of wide necked bifurcation aneurysms: Intrasaccular flow disruption

Wide-necked bifurcation aneurysms (WNBAs) are challenging lesions to treat via both open surgical and endovascular techniques. Presently, there are 3 intrasaccular devices available to address many of the limitations of prior techniques, all of which are at different phases of approval for human use around the world. These devices include the Woven EndoBridge (WEB®) made by MicroVention, the Artisse™ Embolization Device made by Medtronic, and the Contour Neurovascular System™ made by Cerus Endovascular. Although heterogenous in design, these devices rely on the principle of using fine mesh overlying the aneurysm neck to slow blood inflow, promoting stagnation and thrombosis that ultimately leads to healing across the neck and exclusion from the circulation. While our understanding improves as long-term occlusion rates from these devices continue to be studied, the safety profiles and short-term success rates demonstrated in recent studies provide optimism for these innovative intrasaccular devices for the treatment of WNBAs. In this paper, we review these 3 intra-saccular flow disruption devices for use in WNBAs and summarize recent literature and studies of their effectiveness and safety.

Is There a Plateau to the Learning Curve for Acoustic Neuroma Resection?-Experience and Outcomes from a Single Interdisciplinary Team Over Thirty Years

Objective  The evolution of acoustic neuroma (AN) care continues to shift focus on balancing optimized tumor resection and control with preservation of neurological function. Prior learning curve analyses of AN resection have demonstrated a plateau between 20 and 100 surgeries. In this study of 860 consecutive AN surgeries, we investigate the presence of an extended learning curve tail for AN resection. Methods  A retrospective cohort study of AN resections by a single interdisciplinary team between 1988 and 2018 was performed. Proportional odds models and restricted cubic splines were used to determine the association between the timing of surgery and odds of improved postoperative outcomes. Results  The likelihood of improved postoperative House-Brackmann (HB) scores increased in the first 400 procedures, with HB 1 at 36% in 1988 compared with 79% in 2004. While the probability of a better HB score increased over time, there was a temporary decrease in slope of the cubic spline between 2005 and 2009. The last 400 cases continued to see improvement in optimal HB outcomes: adjusted odds of HB 1 score were twofold higher in both 2005 to 2009 (adjusted odds ratio [aOR]: 2.11, 95% confidence interval [CI]: 1.38-3.22, p  < 0.001) and 2010 to 2018 (aOR: 2.18, 95% CI: 1.49-3.19, p  < 0.001). Conclusion  In contrast to prior studies, our study demonstrates the steepest growth for learning, as measured by rates of preservation of facial function outcomes (HB 1), occurs in the first 400 AN resections. Additionally, improvements in patient outcomes continued even 30 years into practice, underlining the importance of lifelong learning.

Dural sinus septum as an underlying cause of intrinsic venous sinus stenosis: Anatomical, clinical, and stent placement considerations

Recently, an interesting study regarding "Dural sinus septum: an underlying cause of cerebral venous sinus stenting failure and complications." was published, to our knowledge, being the launching point of the clinical/interventional applications of this intraluminal variation. Herein, we wish to highlight paramount anatomical, clinical, and stent placement considerations related to DSS located in the dural venous sinus at the posterior cranial fossa and the interventional complications caused by the presence of this variation during stenting procedures.

Effect of Stent Porosity, Platelet Function Test Usage, and Dual Antiplatelet Therapy Duration on Clinical and Radiographic Outcomes After Stenting for Cerebral Aneurysms: A Meta-Analysis

BACKGROUND

The use of stents with various porosities for treating cerebral aneurysms requires dual antiplatelet therapy (DAPT) without clear guidelines on the utility of platelet function tests (PFTs) and the duration of DAPT. We sought to determine the effects of stent porosity, PFT usage, and DAPT duration on the radiographic and clinical outcomes after stenting of cerebral aneurysms.

METHODS

PubMed was searched on March 29, 2021 for studies of cerebral aneurysm stenting that had specified the stent type and DAPT duration. A random effects meta-analysis was used to measure the prevalence of nonprocedural thrombotic and hemorrhagic events, clinical outcomes, aneurysm occlusion, and in-stent stenosis stratified by stent porosity, PFT usage, and DAPT duration.

RESULTS

The review yielded 105 studies (89 retrospective and 16 prospective) with 117 stenting cohorts (50 high porosity, 17 intermediate porosity, and 50 low porosity). In the high-, intermediate-, and low-porosity stenting cohorts, PFT usage was 26.0%, 47.1%, and 62.0% and the mean DAPT duration was 3.51 ± 2.33, 3.97 ± 1.92, and 5.18 ± 2.27 months, respectively. The intermediate-porosity stents showed a reduced incidence of hemorrhagic events (π = 0.32%) compared with low-porosity stents (π = 1.36%; P = 0.01) and improved aneurysm occlusion (π = 6.18%) compared with high-porosity stents (π = 14.42%; P = 0.001) and low-porosity stents (π = 11.71%; P = 0.04). The prevalence of in-stent stenosis was lower for the intermediate-porosity (π = 0.57%) and high-porosity (π = 1.51%) stents than for the low-porosity stents (π = 3.30%; P < 0.05). PFT use had resulted in fewer poor clinical outcomes (π = 3.54%) compared with those without PFT use (π = 5.94%; P = 0.04). The DAPT duration had no effect on the outcomes.

CONCLUSIONS

In the present meta-analysis, which had selected for studies of cerebral aneurysm stenting that had reported the DAPT duration, intermediate-porosity stents and PFT use had resulted significantly improved outcomes. No effect of DAPT duration could be detected.

Operator assessment versus core laboratory adjudication of recanalization following endovascular treatment of acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Successful recanalization after endovascular thrombectomy serves as the primary endpoint in clinical trials and is a crucial predictor of long-term outcomes. Radiographic outcomes for various interventions have been shown to vary based on the type of interpreter, including the site interventionalist compared with an independent reader.

OBJECTIVE

To compare angiographic outcomes in stroke thrombectomy procedures based on the type of reader.

METHODS

A systematic literature search was conducted in Medline, EMBASE, Scopus, and Web-of-Science through February 2022. We included primary studies that reported core laboratory-read and operator angiographic outcomes after mechanical thrombectomy for ischemic stroke. Furthermore, study-defined successful recanalization data were collected.

RESULTS

Eight studies were included with 4797 patients, 51.2% of whom were male. Four thousand, four hundred and thirty-one patients had core readings, and 4211 had operator readings. Study-defined successful recanalization was significantly higher for operator (84%, 3543/4211) examinations than for core laboratory-read (78.4%, 3476/4431) examinations (p<0.001; OR=1.462, 95% CI 1.175 to 1.819). The modified Thrombolysis in Cerebral Infarction (mTICI) scale score of ≥2 b was higher for operator (85%, 3341/3929) examinations than for core laboratory-read (78.6%, 3107/3952) examinations (p<0.001; OR=1.349, 95% CI 1.071 to 1.701). mTICI 3 was significantly higher for operator (54.6%, 1000/1832) examinations than for core laboratory-read (39.9%, 731/1832) examinations (p<0.001; OR=1.823, 95% CI 1.598 to 2.081).

CONCLUSION

Operator angiographic reads are statistically significantly higher than core laboratory-read readings following stroke thrombectomy, especially for complete recanalization. These differences should be considered when interpreting reports of angiographic outcomes after thrombectomy.

Sequential Flow Diversion After Nitinol Stent Placement for a Large, Matricidal Cavernous Internal Carotid Artery Aneurysm: Technical Video

The Surpass Evolve flow diverter is a novel 64-wire braided intravascular stent approved to treat unruptured large or giant saccular wide-neck or fusiform intracranial aneurysms of the intracranial internal carotid artery.1-3 Flow diverting stents have been used for the treatment of previously stented aneurysms, including residual aneurysms following prior flow diversion.5-8 This patient initially presented with a large symptomatic matricidal cavernous ICA aneurysm4 that was treated with stand-alone Neuroform Atlas stenting at an outside hospital. Here we present a video demonstrating the placement of sequential Surpass Evolve flow diverter stents within a Neuroform Atlas nitinol stent.

Occipital Neuralgia following Acoustic Neuroma Resection

Background While postoperative outcomes of acoustic neuroma (AN) resection commonly consider hearing preservation and facial function, headache is a critical quality of life factor. Postoperative headache is described in the literature; however, there is limited discussion specific to occipital neuralgia (ON) following AN resection.

Objective The aim of this study is to investigate the effectiveness of conservative management and surgery.

Methods We conducted a retrospective review of 872 AN patients who underwent resection at our institution between 1988 and 2017 and identified 15 patients (1.9%) that met International Classification of Headache Disorders criteria for ON.

Results Of the 15 ON patients, surgical approaches included 13 (87%) retrosigmoid (RS), one (7%) translabyrinthine (TL), and one (7%) combined RS + TL. Mean clinical follow-up was 119 months (11–263). Six (40%) patients obtained pain relief through conservative management, while the remaining nine (60%) underwent surgery or ablative procedure. Three (38%) patients received an external neurolysis, four (50%) received a neurectomy, one (13%) had both procedures, and one (13%) received two C2 to 3 radio frequency ablations. Of the nine patients who underwent procedural ON treatment, seven (78%) patients achieved pain relief, one patient (11%) continued to have pain, and one patient (11%) was lost to follow-up. Of the six patients whose pain was controlled with conservative management and nerve blocks, five (83%) found relief by using neuropathic pain medication and one (17%) found relief on nonsteroidal anti-inflammatory drug.

Conclusion Our series demonstrates success with conservative management in some, but overall a minority (40%) of patients, reserving decompression only for refractory cases.

Comparison of transarterial n-BCA and Onyx embolization of brain arteriovenous malformations: A single-center 18-year retrospective analysis

OBJECTIVE

Brain arteriovenous malformations (AVM) are commonly treated with endovascular embolization. Due to the rapid evolution of endovascular technology and lack of consistent practice guidelines regarding AVM embolization, further study of AVM embolization outcomes is warranted.

METHODS

We conducted a retrospective review of AVMs embolized at a single center from 2002-2019. Patient demographics, AVM characteristics, intention of embolization, and angiographic and clinical outcome after embolization were recorded. We compared the embolization results of those treated with n-butyl cyanoacrylate (n-BCA) and Onyx.

RESULTS

Over an 18-year period at our institution, 30 (33%) of 92 AVMs were treated with embolization. n-BCA was used in 12 cases and Onyx in 18 cases. Eighty-seven pedicles were embolized over 47 embolization sessions. Fifty percent of AVMs treated with n-BCA underwent more than one embolization session compared to 22% when Onyx was used. The median total percent volume reduction in the n-BCA AVMs was 52% compared to 51% in Onyx AVMs. There were 2 periprocedural complications in the n-BCA cohort and none in the Onyx cohort.

CONCLUSIONS

In this small retrospective series, Onyx and n-BCA achieved similar occlusion results, although n-BCA required more sessions and pedicles embolized to do so.

Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis

BACKGROUND

High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.

METHODS

We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.

RESULTS

Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p = 0.002).

CONCLUSIONS

MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.

Mechanical Thrombectomy With and Without Intravenous Tissue Plasminogen Activator for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis Using Nested Knowledge

Background: Mechanical thrombectomy (MT) is now the standard-of-care treatment for acute ischemic stroke (AIS) of the anterior circulation and may be performed irrespective of intravenous tissue plasminogen activator (IV-tPA) eligibility prior to the procedure. This study aims to understand better if tPA leads to higher rates of reperfusion and improves functional outcomes in AIS patients after MT and to simultaneously evaluate the functionality and efficiency of a novel semi-automated systematic review platform. Methods: The Nested Knowledge AutoLit semi-automated systematic review platform was utilized to identify randomized control trials published between 2010 and 2021 reporting the use of mechanical thrombectomy and IV-tPA (MT+tPA) vs. MT alone for AIS treatment. The primary outcome was the rate of successful recanalization, defined as thrombolysis in cerebral infarction (TICI) scores ≥2b. Secondary outcomes included 90-day modified Rankin Scale (mRS) 0-2, 90-day mortality, distal embolization to new territory, and symptomatic intracranial hemorrhage (sICH). A separate random effects model was fit for each outcome measure. Results: We subjectively found Nested Knowledge to be highly streamlined and effective at sourcing the correct literature. Four studies with 1,633 patients, 816 in the MT+tPA arm and 817 in the MT arm, were included in the meta-analysis. In each study, patient populations consisted of only tPA-eligible patients and all imaging and clinical outcomes were adjudicated by an independent and blinded core laboratory. Compared to MT alone, patients treated with MT+tPA had higher odds of eTICI ≥2b (OR = 1.34 [95% CI: 1.10; 1.63]). However, there were no statistically significant differences in the rates of 90-day mRS 0-2 (OR = 0.98 [95% CI: 0.77; 1.24]), 90-day mortality (OR = 0.94 [95% CI: 0.67; 1.32]), distal emboli (OR = 0.94 [95% CI: 0.25; 3.60]), or sICH (OR = 1.17 [95% CI: 0.80; 1.72]). Conclusions: Administering tPA prior to MT may improve the rates of recanalization compared to MT alone in tPA-eligible patients being treated for AIS, but a corresponding improvement in functional and safety outcomes was not present in this review. Further studies looking at the role of tPA before mechanical thrombectomy in different cohorts of patients could better clarify the role of tPA in the treatment protocol for AIS.

Angioarchitectural features amongst patients with unruptured brain arteriovenous malformations presenting with headache: findings from a single center retrospective review of 76 patients

Background

Brain arteriovenous malformations (AVMs) consist of abnormal connections between arteries and veins via an interposing nidus. While hemorrhage is the most common presentation, unruptured AVMs can present with headaches, seizures, neurological deficits, or be found incidentally. It remains unclear as to what AVM characteristics contribute to pain generation amongst unruptured AVM patients with headaches.

Methods

To assess this relationship, the current study evaluates angiographic and clinical features amongst patients with unruptured brain AVMs presenting with headache. Loyola University Medical Center medical records were queried for diagnostic codes corresponding to AVMs. In patients with unruptured AVMs, we analyzed the correlation between the presenting symptom of headache and various demographic and angiographic features.

Results

Of the 144 AVMs treated at our institution between 1980 and 2017, 76 were unruptured and had sufficient clinical data available. Twenty-three presented with headaches, while 53 patients had other presenting symptoms. Patients presenting with headache were less likely to have venous stenosis compared to those with a non-headache presentation (13 % vs. 36 %, p = 0.044).

Conclusions

Our study suggests that the absence of venous stenosis may contribute to headache symptomatology. This serves as a basis for further study of correlations between AVM angioarchitecture and symptomatology to direct headache management in AVM patients.

Endovascular catheter manometry reliability: a benchtop validation study

OBJECTIVE

Catheter manometry is used frequently in neuroendovascular surgery for assessing cerebrovascular pathology. The accuracy of pressure data with different catheter setups requires further validation.

METHODS

In a silicone human vascular model with a pulsatile pump, pressure measurements were taken through multiple arrangements of 2 guide catheters and 6 microcatheters. The systolic pressure, diastolic pressure, mean pressure, pulse pressure, and area under the curve of the waveform were recorded through catheters with controls at arterial blood pressure ranges. Linear regression modeling was performed, correlating transduction area and relative pulse pressure. Thresholds for acceptable accuracy were ≥ 90%.

RESULTS

Mean pressure demonstrated < 4% variation between all 24 catheter setups and respective controls. A strong linear correlation (r2 = 0.843, p < 0.0005) between microcatheter transduction area and relative pulse pressure with a threshold of 0.50 mm2 was seen (i.e., 0.031-inch inner diameter [ID]). For guide catheters with indwelling microcatheters, there was also a strong linear correlation (r2 = 0.840, p < 0.0005) of transduction area to pulse pressure. The guide catheters with obstructing microcatheters required a transduction area over fourfold higher compared with unobstructed microcatheters (2.21 mm2 vs 0.50 mm2).

CONCLUSIONS

Mean pressure measurements are accurate through microcatheters as small as 0.013-inch ID. Pulse pressure and waveform morphology may require a microcatheter ≥ 0.031-inch ID to achieve 90% accuracy, although the 0.027-inch ID microcatheter reached 85% accuracy. A 0.070-inch guide catheter with a microcatheter ≤ 0.042-inch outer diameter (e.g., Marksman 0.027-inch ID or smaller) allows accurate transduction of pulse pressure. Further validation of these benchtop findings is necessary before application in a clinical setting.

Machine learning models improve prediction of large vessel occlusion and mechanical thrombectomy candidacy in acute ischemic stroke

BACKGROUND AND PURPOSE

Early identification of large vessel occlusions (LVO) and timely recanalization are paramount to improved clinical outcomes in acute ischemic stroke. A stroke assessment that maximizes sensitivity and specificity for LVOs is needed to identify these cases and not overburden the health system with unnecessary transfers. Machine learning techniques are being used for predictive modeling in many aspects of stroke care and may have potential in predicting LVO presence and mechanical thrombectomy (MT) candidacy.

METHODS

Ischemic stroke patients treated at Loyola University Medical Center from July 2018 to June 2019 (N = 286) were included. Thirty-five clinical and demographic variables were analyzed using machine learning algorithms, including logistic regression, extreme gradient boosting, random forest (RF), and decision trees to build models predictive of LVO presence and MT candidacy by area of the curve (AUC) analysis. The best performing model was compared with prior stroke scales.

RESULTS

When using all 35 variables, RF best predicted LVO presence (AUC = 0.907 ± 0.856-0.957) while logistic regression best predicted MT candidacy (AUC = 0.930 ± 0.886-0.974). When compact models were evaluated, a 10-feature RF model best predicted LVO (AUC = 0.841 ± 0.778-0.904) and an 8-feature RF model best predicted MT candidacy (AUC = 0.862 ± 0.782-0.942). The compact RF models had sensitivity, specificity, negative predictive value and positive predictive value of 0.81, 0.87, 0.92, 0.72 for LVO and 0.87, 0.97, 0.97, 0.86 for MT, respectively. The 10-feature RF model was superior at predicting LVO to all previous stroke scales (AUC 0.944 vs 0.759-0.878) and the 8-feature RF model was superior at predicting MT (AUC 0.970 vs 0.746-0.834).

CONCLUSION

Random forest machine learning models utilizing clinical and demographic variables predicts LVO presence and MT candidacy with a high degree of accuracy in an ischemic stroke cohort. Further validation of this strategy for triage of stroke patients requires prospective and external validation.

Woven EndoBridge Embolized Aneurysm Clippings: 2-Dimensional Operative Video

The Woven EndoBridge (WEB) device (MicroVention, Aliso Viejo, California) is an intrasaccular flow disruptor used for the treatment of both unruptured and ruptured intracranial aneurysms. WEB has been shown to have 54% complete and 85% adequate aneurysm occlusion rates at 1-yr follow-up.1 Residual and recurrent ruptured aneurysms have been shown to have a higher risk of re-rupture than completely occluded aneurysms.2 With increased utilization of WEB in the United States, optimizing treatment strategies of residual aneurysms previously treated with the WEB device is essential, including surgical clipping.3,4 Here, we present an operative video demonstrating the surgical clip occlusion of previously ruptured middle cerebral artery and anterior communicating artery aneurysms that had been treated with the WEB device and had sizable recurrence on follow-up angiography. Informed consent was obtained from both patients. Lessons learned include the following: (1) the WEB device is highly compressible, unlike coils; (2) proximal WEB marker may interfere with clip closure; (3) no evidence of WEB extrusion into the subarachnoid space; (4) no more scarring than expected in ruptured cases; and (5) clipping is a feasible option for treating WEB recurrent or residual aneurysms.

Safety and efficacy of intra-arterial fibrinolytics as adjunct to mechanical thrombectomy: a systematic review and meta-analysis of observational data

Background

Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse.

Methods

We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days).

Results

The search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics.

Conclusion

The quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty.

Glomus Vagale Tumor Resection: 2-Dimensional Operative Video

A 37-yr-old female with prior transient left facial paralysis presented with hearing loss, headaches, and resolved transient right facial paralysis. The neurological examination demonstrated normal facial movement, left hearing loss, and left vocal cord weakness. Magnetic resonance imaging demonstrated a >3 cm left paraganglioma traversing the jugular foramen. After obtaining informed consent from the patient, the tumor was embolized and then resected via a combined left postauricular infratemporal fossa and transcervical approach with cranial nerve monitoring. The ossicles were removed and the vertical segment of the facial nerve was skeletonized. The jugular bulb was identified in the hypotympanum and the petrous carotid artery was exposed. The digastric muscle was reflected inferiorly and the extratemporal facial nerve was identified. The stylomandibular ligament was transected to unlock the exposure to the infratemporal fossa. The external carotid branches were ligated. The vagus nerve and cervical sympathetic chain were infiltrated with tumor, requiring resection. The presigmoid dura and occluded jugular bulb were opened to complete the tumor resection, while preserving the medial wall. Despite anatomic preservation, the glossopharyngeal, accessory, and hypoglossal nerves were postoperatively weak and a facial paralysis recovered after 1 wk. Magnetic resonance imaging at 1 yr demonstrated a clean jugular foramen, although a thin rim of tumor remained around the petrous carotid.

Reliability of the Modified TICI Score among Endovascular Neurosurgeons

BACKGROUND AND PURPOSE

The modified TICI score is the benchmark for quantifying reperfusion after mechanical thrombectomy. There has been limited investigation into the reliability of this score. We aim to identify intra-rater and inter-rater reliability of the mTICI score among endovascular neurosurgeons.

MATERIALS AND METHODS

Four independent endovascular neurosurgeons (raters) reviewed angiograms of 67 patients at 2 time points. κ statistics assessed inter- and intrarater reliability and compared raters'-versus-proceduralists' scores. Reliability was also assessed for occlusion location and by dichotomizing modified TICI scores (0-2a versus 2b-3).

RESULTS

Interrater reliability was moderate-to-substantial, weighted κ = 0.417-0.703, overall κ = 0.374 (P < .001). The dichotomized modified TICI score had moderate-to-substantial interrater agreement, κ statistics = 0.468-0.715, overall κ = 0.582 (P < .001). Intrarater reliability was moderate-to-almost perfect, weighted κ = 0.594-0.81. The dichotomized modified TICI score had substantial-to-almost perfect reliability, κ = 0.632-0.82. Proceduralists had fair-to-moderate agreement with raters, weighted κ = 0.348-0.574, and the dichotomized modified TICI score had fair-to-moderate agreement, κ = 0.365-0.544. When proceduralists and raters disagreed, proceduralists' scores were higher in 79.6% of cases. M1 followed by ICA occlusions had the highest agreement.

CONCLUSIONS

The modified TICI score is a practical metric for assessing reperfusion after mechanical thrombectomy, though not without limitations. Agreement improved when scores were dichotomized around the clinically relevant threshold of successful revascularization. Interrater reliability improved with time, suggesting that formal training of interventionalists may improve reporting reliability. Agreement of the modified TICI scale is best with M1 and ICA occlusion and becomes less reliable with more distal or posterior circulation occlusions. These findings should be considered when developing research trials.

Pediatric vestibular schwannomas: case series and a systematic review with meta-analysis

OBJECTIVE

Sporadic unilateral vestibular schwannomas are rare in the pediatric population. Little has been reported in the literature on the presentation, tumor size, response to surgical treatment, and recurrence rates in these younger patients. The authors' goal was to describe their institutional experience with pediatric sporadic vestibular schwannomas and to conduct a meta-analysis of the existing literature to provide further insight into the presentation, tumor characteristics, and surgical outcomes for these rare tumors to help direct future treatment strategies.

METHODS

The authors performed a retrospective review of all patients 21 years of age or younger with unilateral vestibular schwannomas and without neurofibromatosis type 2 who underwent resection by the senior authors between 1997 and 2019. A systematic review of the literature and meta-analysis was also performed by entering the search terms "pediatric" and "vestibular schwannoma" or "acoustic neuroma," as well as "sporadic" into PubMed. Presentation, treatment, clinical outcomes, and follow-up were analyzed.

RESULTS

Fifteen patients were identified at the authors' institution, ranging in age from 12 to 21 years (mean 16.5 years). Common presenting symptoms included hearing loss (87%), headache (40%), vertigo (33%), ataxia (33%), and tinnitus (33%). At the time of surgery, the mean tumor size was 3.4 cm, with four 1-cm tumors. Four patients had residual tumor following their first surgery, 3 (75%) of whom had significant radiographic regrowth that required further treatment. The literature review identified an additional 81 patients from 26 studies with patient-specific clinical data available for analysis. This resulted in a total of 96 reported patients with an overall average age at diagnosis of 12.1 years (range 6-21 years) and an average tumor size of 4.1 cm.

CONCLUSIONS

Pediatric vestibular schwannomas present similarly to those in adults, although symptoms of mass effect are more common, as these tumors tend to be larger at diagnosis. Some children are found to have small tumors and can be successfully treated surgically. Residual tumors in pediatric patients were found to have a higher rate of regrowth than those in their adult counterparts.

'Railroad switch' technique for stent-assisted coil embolization of a wide-neck bifurcation intracranial aneurysm: technical note

Preservation of the posterior cerebral arteries during endovascular treatment of wide-neck basilar bifurcation aneurysms remains a technical challenge despite recent device innovations. We present a novel stent deployment technique, the 'railroad switch', to protect both posterior cerebral arteries during treatment of a recurrent basilar bifurcation aneurysm. Following asymmetric basilar-posterior cerebral artery stent deployment, favoring distal placement in a posterior cerebral artery, advancement of a jailed microcatheter will advance the proximal stent into the aneurysm, protecting both posterior cerebral arteries and the native basilar terminus. This novel maneuver offers interventionalists another application of commonly used intracranial stents for endovascular management of complex basilar bifurcation aneurysms.

Murphey's teat: history and insight into an enigmatic cerebrovascular eponym

Dr. Francis Murphey of the Semmes-Murphey Clinic in Memphis recognized that a focal sacculation on the dome of an aneurysm may be angiographic evidence of a culpable aneurysm in the setting of subarachnoid hemorrhage with multiple intracranial aneurysms present. This has been referred to as a Murphey's "teat," "tit," or "excrescence." With variability in terminology, misspellings in the literature, and the fact that Dr. Murphey did not formally publish this important work, the authors sought to clarify the meaning and investigate the origins of this enigmatic cerebrovascular eponym.

Pediatric primary spinal atypical teratoid rhabdoid tumor: a case series and review of the literature

Atypical teratoid rhabdoid tumors (ATRTs) are rare malignant central nervous system tumors, commonly occurring before 3 years of age. Median overall survival (OS) of patients with these tumors is about 1 year, despite aggressive multimodal therapy. Pediatric primary spinal ATRTs are even more rare, with fewer than 50 cases reported. The authors present a series of four patients who were treated at Ann and Robert H. Lurie Children's Hospital of Chicago in the period from 1996 to 2017.These patients, with ages 2-11 years, presented with pain and a decline in motor functions. They were found to have lesions in the lumbar, thoracic, and/or cervical spine. One patient's tumor was intramedullary with exophytic components, while another patient's tumor had both intra- and extradural components. All patients underwent resection followed by chemotherapy (systemic and intrathecal). Two patients had fractionated radiation therapy and one had an autologous stem cell transplant. Three patients are known to be deceased (OS 8.5-45 months). The fourth patient was in remission 19 years after her initial diagnosis. To the authors' knowledge, this is the largest series of pediatric primary spinal ATRTs documented at a single institution. These cases illustrate a variety of presentations of spinal ATRT and add to the body of literature on this aggressive pathology.A systematic MEDLINE search was also conducted using the keywords "atypical teratoid rhabdoid tumor," "pediatric spinal rhabdoid tumor," and "malignant rhabdoid tumor spine." Reports were included for patients younger than 21 years, without evidence of intracranial or systemic disease at the time of diagnosis. Clinical characteristics and outcomes of the four institutional cases were compared to those in the literature. This review yielded an additional 48 cases of primary pediatric spinal ATRTs reported in the English-language literature. Patients (ages 2 months to 19 years) presented with symptoms of pain, regression of motor function, and spinal cord compression. The majority of tumors were intradural (14 extramedullary, 8 intramedullary, 1 both). Eleven cases in the literature described tumors limited to extradural structures, while 10 tumors involved the intra- and extradural spine. Four reports did not specify tumor location. Although rare, spinal ATRT should be considered in the differential diagnosis of pediatric patients presenting with a new spinal mass.

Evaluation of the Intracranial Flow Alteration during Manual Syringe and Continuous Pump Aspiration

GOALS

While mechanical thrombectomy (MT) has been shown to be effective in the treatment of acute large vessel occlusions, adjunctive measures, such as balloon guide catheters (BGC) and aspiration techniques, are utilized heterogeneously. Clarifying the effects of aspiration applied to the anterior cerebral circulation with proximal flow arrest can shed light on embolic protection during MT.

MATERIALS AND METHODS

Manual and pump aspiration were applied through a BGC in a synthetic cerebrovascular model with a 60 ml syringe and a Penumbra pump, respectively. Flow direction was observed during the procedure with fluorescent particles and ultraviolet light. Flow rates were monitored at the simulated internal carotid artery and middle cerebral artery (MCA).

FINDINGS

Both aspiration methods produced retrograde flow in all the modeled cerebrovascular segments. In the syringe aspiration methods, an interval phase occurred during the experimental trial in which suction forces paused and MCA flow became anterograde through posterior communication artery collateral circulation.

CONCLUSION

Flow patterns vary with different methods of aspiration. With proximal flow arrest, continuous aspiration methods induce constant retrograde flow in all vessels, whereas manual aspiration demonstrates various flow changes, including periods of anterograde flow during the procedure, which may be less effective at distal re-embolization prevention.

Basilar Apex Aneurysms in the Setting of Carotid Artery Stenosis: Case Series and Angiographic Anatomic Study

Background:

Intracranial aneurysms (IAs) are life-threatening lesions known within the literature to be found incidentally during routine angiographic workup for carotid artery stenosis (CAS). As IAs are associated with vascular shear stress, it is reasonable to expect that altered flow demands within the anterior circulation, such as with CAS, increase compensatory flow demands via the Circle of Willis (COW) and may induce similar stress at the basilar apex.

Objective:

We present a series of nine unruptured basilar apex aneurysms (BAA) with CAS and a comparative radiographic analysis to BAA without CAS.

Methods:

Twenty-three patients with BAA were retrospectively identified using records from 2011 to 2016. CAS by North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, morphology of BAA, competency of COW, and anatomic relationships within the posterior circulation were examined independently by a neuroradiologist using angiographic imaging.

Results:

Nine (39%) of the twenty-three BAA patients had CAS, with six having stenosis ≥50%. Four (67%) of the patients with ≥50% CAS demonstrated aneurysm flow angles contralateral to the side with highest CAS. Additionally, the angle between the basilar artery (BA) trajectory and aneurysm neck was observed to be smaller in patients with ≥50% CAS (61 vs 74 degrees). No significant differences in COW patency, posterior circulation morphology, and degree of stenosis were observed.

Conclusion:

Changes in the cervical carotid arteries may lead to blood flow alterations in the posterior circulation that increase the propensity for BAA formation. Posterior circulation imaging can be considered in CAS patients to screen for BAA.

Lower-dose perioperative steroid protocol during endoscopic endonasal pituitary adenoma resection

Background:

Perioperative steroid management for pituitary adenoma resections is multifaceted due to possible hypothalamic–pituitary–adrenal (HPA) axis disruption. Although many different strategies have been proposed, there is no standard protocol for prophylaxis of potential hypocortisolemia.

Methods:

We performed a retrospective analysis of consecutive endoscopic endonasal pituitary adenoma resections. Before March 2016, patients received ≥100 mg of hydrocortisone intraoperatively followed by 2 mg of dexamethasone immediately postoperatively in most of the patients. Subsequently, patients received only 50 mg of hydrocortisone intraoperatively. A morning cortisol level was checked on postoperative day (POD) 2, and if it was <10 mcg/dL, patients remained on maintenance hydrocortisone. At 6 weeks, serum cortisol was redrawn and low-dose therapy was weaned when indicated.

Results:

Of those who received ≥100 mg of hydrocortisone, 8 of 24 (33.3%) were discharged on hydrocortisone compared to 1 of 14 (7.1%) who received 50 mg. 18 of 24 (75%) of ≥100 mg group received dexamethasone on POD 1, and of those, 8 (44.4%) were discharged on hydrocortisone. Of those who received ≥100 mg and were on outpatient steroid therapy initially, 3 of 8 (37.5%) required continuation after 6 weeks compared to none who received 50 mg. There was an association between patient’s intraoperative/immediate postoperative steroid use and steroid continuation at discharge.

Conclusion:

Through our experience, we hypothesize that ≥100 mg of hydrocortisone intraoperatively followed by postoperative dexamethasone may be overly suppressive in patients with otherwise normally functioning HPA. A 50 mg intraoperative dose alone may be considered to lower rates of unnecessary steroid regimens postoperatively.

Stent-assisted coil embolization of MCA aneurysm via a trans-posterior communicating artery access

External carotid artery (ECA) to internal carotid artery (ICA) bypass is a well-established procedure for the treatment of chronic ischemic diseases of the carotid artery. Rarely de novo aneurysms can develop at the site of anastomosis. The treatment of these aneurysms can be very challenging due to various factors, including the presence of graft, previous craniotomy, atherosclerotic vessels, and lack of direct access. In this video the authors report and discuss the management of a right middle cerebral artery (MCA) wide-necked de novo aneurysm by stent-assisted coiling through a retrograde trans-posterior communicating artery access.

The video can be found here: https://youtu.be/MBKolPvOErU.

Morphologic variations of the second cervical vertebra in Down syndrome compared with age-matched peers

OBJECTIVEAtlantoaxial instability is an important cause of pain and neurological dysfunction in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. This study provides a quantitative analysis of C2 morphology in DS patients compared with their peers without DS to identify differences that must be considered for the safe placement of instrumentation.METHODSA retrospective chart review identified age-matched patients with and without DS with a CT scan of the cervical spine. Three-dimensional reconstructions of these scans were made with images along the axis of, and perpendicular to, the pars, lamina, facet, and transverse foramen of C2 bilaterally. Two of the authors performed independent measurements of anatomical structures using these images, and the average of the 2 raters' measurements was recorded. Pedicle height and width; pars axis length (the distance from the facet to the anterior vertebral body through the pars); pars rostrocaudal angle (angle of the pars axis length to the endplate of C2); pars axial angle (angle of the pars axis length to the median coronal plane); lamina height, length, and width; lamina angle (angle of the lamina length to the median coronal plane); and transverse foramen posterior distance (the distance from the posterior wall of the transverse foramen to the tangent of the posterior vertebral body) were measured bilaterally. Patients with and without DS were compared using a mixed-effects model accounting for patient height.RESULTSA total of 18 patients with and 20 patients without DS were included in the analysis. The groups were matched based on age and sex. The median height was 147 cm (IQR 142-160 cm) in the DS group and 165 cm (IQR 161-172 cm) in the non-DS group (p < 0.001). After accounting for variations in height, the mean pars rostrocaudal angle was greater (50.86° vs 45.54°, p = 0.004), the mean transverse foramen posterior distance was less (-1.5 mm vs +1.3 mm, p = 0.001), and the mean lamina width was less (6.2 mm vs 7.7 mm, p = 0.038) in patients with DS.CONCLUSIONSPatients with DS had a steeper rostrocaudal trajectory of the pars, a more posteriorly positioned transverse foramen posterior wall, and a narrower lamina compared with age- and sex-matched peers. These variations should be considered during surgical planning, as they may have implications to safe placement of instrumentation.

Resection of an Embolized Cirsoid Aneurysm With Intracranial Venous Drainage: 2-Dimensional Operative Video

Cirsoid aneurysms, also known as scalp arteriovenous malformations (AVM), are rare congenital extracranial vascular anomalies that often present as an enlarging pulsatile scalp mass. A 14-yr-old male presented with a pulsatile scalp lesion that was first noticed 3 yr prior and had progressively enlarged. No history of trauma was reported. MRI demonstrated a 4 cm wide and 2 cm tall nidus and catheter angiography was performed to further define the vascular supply and drainage. The patient underwent transvenous endovascular embolization followed by surgical excision via a bicoronal incision, as shown in this operative video. Care was taken to identify, cauterize, and transect feeding vessels from the superficial temporal, supratrochlear, and supraorbital arteries circumferentially to completely devascularize and resect the galeal nidus from overlying scalp tissue and underlying pericranium. Previously unreported in the literature, transosseous emissary veins partially draining the lesion were noted on angiography and were waxed thoroughly during surgery. Six-month follow-up examination demonstrated a well-healed incision without evidence of AVM recurrence. The unique venous drainage of this cirsoid aneurysm highlights the value of diagnostic angiography to fully characterize these rare and complex vascular lesions prior to pursuing definitive treatment.

 IRB approval was obtained from the Ann & Robert H. Lurie Children's Hospital of Chicago Institutional Review Board (IRB #2018-1799). The IRB waives the requirement of obtaining informed consent for this study in accordance with 45 CFR 46.116(d).

Extracranial-to-Intracranial Bypass for Pressor Dependent Cerebrovascular Insufficiency: Modified Classification and Representative Case

BACKGROUND

While some randomized clinical trials have reduced the indications for cerebral revascularization in the secondary prevention of ischemic stroke, a distinct subset of patients with blood pressure augmentation dependent cerebrovascular insufficiency due to large vessel occlusions remains unaddressed. With the recent paradigm shifts in acute ischemic stroke care, the role of extracranial to intracranial (EC-IC) bypass must be re-addressed when endovascular intervention is not a feasible option. We submit a refined classification of cerebrovascular insufficiency with a category called Pressor-Dependent Cerebrovascular Insufficiency (PD-CVI) for whom EC-IC bypass may be indicated.

CLINICAL PRESENTATION

A 61-year-old female former smoker presented with one day of intermittent left faciobrachial weakness and was found to have middle cerebral artery and cervical internal carotid artery occlusions. On admission to the intensive care unit, she was found to have PD-CVI with an intravenous pressor dependent blood pressure threshold over which she had near resolution of her neurological deficits. With endovascular intervention precluded given the ICA occlusion, she underwent an urgent right sided EC-IC bypass. The procedure was without complication, with careful attention to maintaining hypertension perioperatively. She required no pressors postoperatively and was neurologically intact at three months post-operatively.

CONCLUSION

With recent advances in acute ischemic stroke care, there remains a need for careful consideration of cerebral revascularization surgery in patients with evidence of PD-CVI who may be precluded from or failed endovascular intervention.

Multiple intracranial aneurysms in a patient with type I Gaucher disease: a case report and literature review

Multiple intracranial aneurysms (IAs) have never been reported in a patient with Gaucher disease (GD). A 69-year-old-female with type I GD presented with a left sixth nerve palsy due to a large posterior inferior cerebellar artery (PICA) aneurysm. Cerebral angiography demonstrated fifteen unruptured IAs (UIAs).

Assessment of human placenta as an ex-vivo vascular model for testing of liquid embolic agent injections with adjunctive techniques

PURPOSE

This project sought to test the utility of post-delivery human placenta (HP) as a vascular model for liquid embolic agent (LEA) simulation, along with adjunctive techniques.

MATERIALS AND METHODS

Twelve LEA injections were performed under fluoroscopy in HP with two reflux control methods: dual lumen 'mini' balloon-catheter (n=9); and injection after proximal nBCA plug formation through a second microcatheter ('pressure cooker') (n=3). Measured outcomes included liquid embolic agent (LEA) advancement and reflux. Reflux was categorized into three grades: grade 0=no reflux; grade 1=occlusion of side branches without reflux beyond the balloon or plug; and grade 2=reflux beyond the balloon or plug.

RESULTS

Simulation success was greater when a balloon was used rather than with a nBCA plug (89% vs 33%, P=0.054). In eight successful balloon-assisted injections, the reflux grades were: 50% grade 0; 12.5% grade 1; and 37.5% grade 2. The one successful nBCA plug injection had grade 2 reflux. All grade 2 balloon injections occurred when the balloon was positioned across a vessel bifurcation.

CONCLUSIONS

HP provides excellent simulation for liquid embolic agents with a dual lumen balloon catheter.

Bilateral Through-and-Through Trajectory of a Low-Velocity Transcranial Penetrating Foreign Object in a Twelve-Month-Old

A 12-month-old girl sustained a penetrating intracranial trauma of a thin aluminum rod traversing from the left frontal bone and exiting the right occipital bone. The rod entered the left anterior frontal lobe, traveled through the ventricular system, narrowly missed the right posterior cerebral artery by less than 1 mm and exited through the right cerebellum. The rod was surgically extracted, and the child remained neurologically intact. Pre- and postoperative vascular imaging, antibiotics, seizure prophylaxis and surgical planning are paramount to successful care of these delicate cases.

Use of flow-diverting stents as salvage treatment following failed stent-assisted embolization of intracranial aneurysms

Flow-diverting stents, including the Pipeline embolization device (PED) and Silk, have been beneficial in the treatment of aneurysms previously unable to be approached via endovascular techniques. Recurrent aneurysms for which stent-assisted embolization has failed are a therapeutic challenge, given the existing intraluminal construct with continued blood flow into the aneurysm. We report our experience using flow-diverting stents in the repair of 25 aneurysms for which stent-assisted embolization had failed. Nineteen (76%) of these aneurysms at the 12-month follow-up showed improved Raymond class occlusion, with 38% being completely occluded, and all aneurysms demonstrated decreased filling. One patient developed a moderate permanent neurologic deficit. Appropriate stent sizing, proximal and distal construct coverage, and preventing flow diverter deployment between the previously deployed stent struts are important considerations to ensure wall apposition and prevention of endoleak. Flow diverters are shown to be a reasonable option for treating previously stented recurrent cerebral aneurysms.

The endonasal approach for treatment of cerebral aneurysms: A critical review of the literature

The last two decades of neurosurgery have seen flourishing use of the endonasal approach for the treatment of skull base tumors. Safe and effective resections of neoplasms requiring intracranial arterial dissection have been performed using this technique. Recently, there have been a growing number of case reports describing the use of the endonasal approach to surgically clip cerebral aneurysms. We review the use of these approaches in intracranial aneurysm clipping and analyze its advantages, limitations, and consider future directions. Three major electronic databases were queried using relevant search terms. Pertinent case studies of unruptured and ruptured aneurysms were considered. Data from included studies were analyzed. 8 case studies describing 9 aneurysms (4 ruptured and 5 unruptured) treated by the endonasal approach met inclusion criteria. All studies note the ability to gain proximal and distal control and successful aneurysm obliteration was obtained for 8 of 9 aneurysms. 1 intraoperative rupture occurred and was controlled, and delayed complications of cerebrospinal fluid leak, vasospasm, and hydrocephalus occurred in 1, 1, and 2 patients, respectively. Described limitations of this technique include aneurysm orientation and location, the need for lower profile technology, and challenges with handling intraoperative rupture. The endonasal approach for clipping of intracranial aneurysms can be an effective approach in only very select cases as demonstrated clinically and through cadaveric exploration. Further investigation with lower profile clip technology and additional studies need to be performed. Options of alternative therapy, limitations of this approach, and team experience must first be considered.

Stent-assisted embolization of 100 middle cerebral artery aneurysms

OBJECT

The introduction of intracranial stents to aneurysm treatment allows endovascular repair of nearly all aneurysms, but the safety and durability of stent-assisted embolization of middle cerebral artery (MCA) aneurysms is unclear.

METHODS

Ninety-one patients with 100 complex MCA aneurysms not amenable to simple coiling were treated with stent-assisted embolization as a first option. Technical and clinical results, initial follow-up imaging, and long-term annual MR angiography (MRA) were reviewed.

RESULTS

Intracranial stents were successfully deployed in all 100 aneurysms. There was 1 case of significant neurological morbidity (1%) and 1 case of death (1%) related to treatment. Initial posttreatment angiography revealed complete occlusion of 48 aneurysms (48%), a residual neck in 21 (21%), and residual aneurysm filling in 31 (31%). Follow-up imaging performed in 85 (90.4%) of a possible 94 aneurysms showed complete occlusion of 77 aneurysms (90.6%), residual neck in 3 (3.5%), and residual filling in 5 (5.9%). Four aneurysms (4.7%) required retreatment. Long-term MRA follow-up revealed stability or progressive thrombosis in 47 (97.9%) of 48 aneurysms. In 11 patients Y-configuration stenting caused only 1 minor complication and provided durable occlusion in all cases.

CONCLUSIONS

Stent-assisted techniques increase the number of aneurysms that may be treated endovascularly and represent an acceptable alternative to craniotomy. Stents provided adequate vessel reconstruction, low complication rates, and good long-term occlusion.

Visualization of mouse pancreas architecture using MR microscopy

Pancreatic diseases, which include diabetes, pancreatitis, and pancreatic cancer, are often difficult to detect and/or stage, contributing to a reduced quality of life and lifespan for patients. Thus, there is need for a technology that can visualize tissue changes in the pancreas, improve understanding of disease progression, and facilitate earlier detection in the human population. Because of low spatial resolution, current clinical magnetic resonance imaging (MRI) at low field strength has yet to fully visualize the exocrine, endocrine, vascular, and stromal components of the pancreas. We used high field strength magnetic resonance microscopy (μMRI) to image mouse pancreas ex vivo without contrast agents at high spatial resolution. We analyzed the resulting high-resolution images using volume rendering to resolve components in the pancreas, including acini, islets, blood vessels, and extracellular matrix. Locations and dimensions of pancreatic components as seen in three-dimensional μMRI were compared with histological images, and good correspondence was found. Future longitudinal studies could expand on the use of in vivo μMRI in mouse models of pancreatic diseases. Capturing three-dimensional structural changes through μMRI could help to identify early cellular and tissue changes associated with pancreatic disease, serving as a mode of improved detection in the clinic for endocrine and exocrine pathologies.

Abstract LB-382: MR microscopy detects architectural changes in the pancreas of mutant Kras mouse models of pancreatic cancer

Pancreatic cancer (PC) is a devastating disease due to the lack of early detection resulting in late diagnosis and poor prognosis. Thus, there is a need for a technology that can visualize morphological and cellular changes in the pancreas when the cancer cells are at a pre-invasive stage. Nearly 90% of human PC have a mutation in Kras and several mouse models that express mutant Kras develop precancerous lesions resembling those in humans. Using MR microimaging, we examined pancreata from EL-Kras (ELK) and Pdx1-Cre/LSL-Kras (PCK) mice which target mutant Kras to the pancreas via unique approaches. EL targeting employs human mutant Kras where nearly all acinar cells express this oncogene, while Pdx1 targeting uses a mutation in an endogenous mouse Kras allele. The source (human vs. mouse), targeting (EL vs. Pdx1) and delivery (artificial vs. endogenous) of mutant Kras contribute to altered phenotypes including differences in normal appearing parenchyma, frequency of acinar-ductal metaplasia, precancerous lesion formation, and progression to advanced disease. We examined pancreas from both mutant Kras mouse models using MR microimaging and compared their MR signature to that of control mice. Fixed pancreata were imaged on a 14.1T microimager. T2-weighted, high spatial resolution images were acquired with fat suppression using a fast spin-echo 3D imaging protocol and isotropic pixel size of ∼70μm. MR data was reconstructed to provide volume images of the pancreatic components and their spatial relationship to each other. T2-weighted MR microimages had high spatial resolution and excellent endogenous contrast that enabled the visualization of acinar cells, islets and stroma in the normal pancreas. T2-weighted images of ELK pancreas showed poor contrast and delineation between acinar cells, islets and stroma indicating changes in their T2-relaxation times possibly as a result of changes at the cellular level. Contrast between pancreatic components in the PCK pancreas was similar to control. Volume images of the pancreas from both mutant Kras mice showed unique differences from control in stromal architecture. While the normal mouse pancreas had a dense, concentrated network of stroma, the ELK mouse pancreas showed only a sparse network with reduced signal intensity, and the PCK mouse pancreas had a more extensive network of stroma. These differences in stromal architecture of mutant Kras pancreas detected by MR microscopy most likely represent transgene-induced alterations in the composition of extracellular matrix (ECM) and might have implications for the development of pancreatic pre-cancerous lesions and cancer. Ours is the first report of MR microimaging of ECM in the intact mouse pancreas of relevant mouse models of PC. Deciphering the differences in ECM among these two models is the focus of ongoing work. Our results suggest that MR volume imaging at high spatial resolution may have potential in detecting morphological and cellular changes associated with pre-invasive and invasive stages of PC. (Supported by Jay Wertheimer Pancreatic Cancer Research Fund and NIH S10 RR13880)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-382.