Enhancing thromboresistance of neurovascular nickel-titanium devices with responsive heparin hydrogel coatings

BACKGROUND

Neurointerventional devices, particularly laser-cut thin-strut stents made of self-expanding nickel-titanium alloy, are increasingly utilized for endovascular applications in intracranial arteries and dural venous sinuses. Preventing thrombosis and stroke necessitates systemic anticoagulant and antiplatelet therapies with the risk of bleeding complications. Antithrombotic coatings present a promising solution.

METHODS

In this study, we investigated the potential of hydrogels composed of four-armed poly(ethylene glycol) (starPEG) and heparin, with or without coagulation-responsive heparin release, as coatings for neurovascular devices to mitigate blood clot formation. We evaluated the feasibility and efficacy of these coatings on neurovascular devices through in vitro Chandler-Loop assays and implantation experiments in the supra-aortic arteries of rabbits.

RESULTS

Stable and coagulation-responsive starPEG-heparin hydrogel coatings exhibited antithrombotic efficacy in vitro, although with a slightly reduced thromboprotection observed in vivo. Furthermore, the hydrogel coatings demonstrated robustness against shear forces encountered during deployment and elicited only marginal humoral and cellular inflammatory responses compared with the reference standards.

CONCLUSION

Heparin hydrogel coatings offer promising benefits for enhancing the hemocompatibility of neurointerventional devices made of self-expanding nickel-titanium alloy. The variance in performance between in vitro and in vivo settings may be attributed to differences in low- and high-shear blood flow conditions inherent to these models. These models may represent the differences in venous and arterial systems. Further optimization is warranted to tailor the hydrogel coatings for improved efficacy in arterial applications.

The pEGASUS-HPC stent system for intracranial arterial stenosis: a single-center case series

BACKGROUND

Intracranial arterial stenting is a technique for the treatment of symptomatic stenosis. In this single-center retrospective case series we evaluated a novel low profile laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC, Phenox GmbH, Bochum, Germany) for the treatment of intracranial stenosis in the setting of acute ischemic stroke and elective cases.

METHODS

All patients treated with pEGASUS-HPC for one or more intracranial arterial stenoses at our institution were retrospectively included. Clinical, imaging and procedural parameters as well as clinical and imaging follow-up data were collected.

RESULTS

We performed 43 interventions in 41 patients with 42 stenoses in our neurovascular center between August 2021 and February 2024. Twenty-one patients (51.2%) were female and the mean±SD age was 71±10.8 years. Thirty-seven (86.1%) procedures were performed in the setting of endovascular acute ischemic stroke treatment. Technical or procedural complications occurred in seven patients (16.3%), six in the thrombectomy group and one in the elective group. One stent-related hemorrhagic complication (subarachnoid hemorrhage) occurred in emergency cases and symptomatic intracerebral hemorrhage occurred in one patient treated in an elective setting. Overall stenosis reduction following pEGASUS-HPC stent implantation was 53.0±18.0%. On follow-up imaging, which was available for 16 patients (37.2%) after an average of 32±58.6 days, 62.5% of the stents were patent.

CONCLUSION

Our single-center case series demonstrates the feasibility of using the pEGASUS-HPC stent system, especially in emergency situations when thrombectomy fails.

Impact of Vaccination Status on Outcome of Patients With COVID-19 and Acute Ischemic Stroke Undergoing Mechanical Thrombectomy

BACKGROUND

Data on impact of COVID-19 vaccination and outcomes of patients with COVID-19 and acute ischemic stroke undergoing mechanical thrombectomy are scarce. Addressing this subject, we report our multicenter experience.

METHODS AND RESULTS

This was a retrospective analysis of patients with COVID-19 and known vaccination status treated with mechanical thrombectomy for acute ischemic stroke at 20 tertiary care centers between January 2020 and January 2023. Baseline demographics, angiographic outcome, and clinical outcome evaluated by the modified Rankin Scale score at discharge were noted. A multivariate analysis was conducted to test whether these variables were associated with an unfavorable outcome, defined as modified Rankin Scale score >3. A total of 137 patients with acute ischemic stroke (48 vaccinated and 89 unvaccinated) with acute or subsided COVID-19 infection who underwent mechanical thrombectomy attributable to vessel occlusion were included in the study. Angiographic outcomes between vaccinated and unvaccinated patients were similar (modified Thrombolysis in Cerebral Infarction ≥2b: 85.4% in vaccinated patients versus 86.5% in unvaccinated patients; P=0.859). The rate of functional independence (modified Rankin Scale score, ≤2) was 23.3% in the vaccinated group and 20.9% in the unvaccinated group (P=0.763). The mortality rate was 30% in both groups. In the multivariable analysis, vaccination status was not a significant predictor for an unfavorable outcome (P=0.957). However, acute COVID-19 infection remained significant (odds ratio, 1.197 [95% CI, 1.007-1.417]; P=0.041).

CONCLUSIONS

Our study demonstrated no impact of COVID-19 vaccination on angiographic or clinical outcome of COVID-19-positive patients with acute ischemic stroke undergoing mechanical thrombectomy, whereas worsening attributable to COVID-19 was confirmed.

Endovascular Treatment for Acute Isolated Internal Carotid Artery Occlusion : A Propensity Score Matched Multicenter Study

PURPOSE

The benefit of endovascular treatment (EVT) in patients with acute symptomatic isolated occlusion of the internal carotid artery (ICA) without involvement of the middle and anterior cerebral arteries is unclear. We aimed to compare clinical and safety outcomes of best medical treatment (BMT) versus EVT + BMT in patients with stroke due to isolated ICA occlusion.

METHODS

We conducted a retrospective multicenter study involving patients with isolated ICA occlusion between January 2016 and December 2020. We stratified patients by BMT versus EVT and matched the groups using propensity score matching (PSM). We assessed the effect of treatment strategy on favorable outcome (modified Rankin scale ≤ 2) 90 days after treatment and compared reduction in NIHSS score at discharge, rates of symptomatic intracranial hemorrhage (sICH) and 3‑month mortality.

RESULTS

In total, we included 149 patients with isolated ICA occlusion. To address imbalances, we matched 45 patients from each group using PSM. The rate of favorable outcomes at 90 days was 56% for EVT and 38% for BMT (odds ratio, OR 1.89, 95% confidence interval, CI 0.84-4.24; p = 0.12). Patients treated with EVT showed a median reduction in NIHSS score at discharge of 6 points compared to 1 point for BMT patients (p = 0.02). Rates of symptomatic intracranial hemorrhage (7% vs. 4%; p = 0.66) and 3‑month mortality (11% vs. 13%; p = 0.74) did not differ between treatment groups. Periprocedural complications of EVT with early neurological deterioration occurred in 7% of cases.

CONCLUSION

Although the benefit on functional outcome did not reach statistical significance, the results for NIHSS score improvement, and safety support the use of EVT in patients with stroke due to isolated ICA occlusion.

Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study

BACKGROUND

Non-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if specific devices or novel coating technologies may impact their occurrence.

METHODS

We conducted a multicenter study on the incidence of NICE lesions after flow diverter (FD) implantation for cerebral aneurysm treatment.

RESULTS

Eight centers identified 15 patients and provided detailed data. The clinical presentation ranged from asymptomatic to hemiplegia and cognitive impairment. The mean time to diagnosis after treatment was 65.1±101.5 days. Five centers disclosed information on all of their 1201 FD procedures during the inclusion period (2015-2022), during which 12 patients were diagnosed with NICE lesions in these institutions-that is, an incidence of 1%. FD coatings did not increase the incidence (6/591 patients (1%) treated with surface-modified FD vs 6/610 patients (1%) treated with bare FD; P=1.00). Significantly increased rates of 3.7% (6 cases in 161 procedures; P<0.01) and 3.3% (5 cases in 153 procedures; P<0.01) were found with stents of two specific product lines. The use of one product line was associated with a significantly lower incidence (0 cases in 499 procedures (0%); P<0.01).

CONCLUSIONS

Novel stent coatings are not associated with an increased incidence of NICE lesions. The incidence rate of 1% suggests that these lesions may occur more often after flow diversion than after other endovascular treatments. We found a concerning accumulation of NICE lesion cases when FDs from two product families were used.

The pEGASUS-HPC stent system for stent-assisted coiling of cerebral aneurysms: a multicenter case series

BACKGROUND

Stent-assisted coiling (SAC) is a well-established method for treatment of wide-necked intracranial aneurysms. In this multicenter, retrospective case series we evaluated SAC with a new low-profile, laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC) for the treatment of intracranial aneurysms.

METHODS

Patients treated with pEGASUS-HPC SAC for one or more intracranial aneurysms were retrospectively included. Clinical, imaging, and procedural parameters as well as clinical and imaging follow-up data were recorded.

RESULTS

We treated 53 aneurysms in 52 patients in six neurovascular centers between August 2021 and November 2022. Thirty-seven patients (69.8%) were female. Mean age was 57 (±11.7) years. Twenty-nine patients were treated electively, 23 in the acute phase (22 with aneurysmal subarachnoid hemorrhage (SAH), and 1 with a partially thrombosed aneurysm causing ischemic events). One intraprocedural thromboembolic event and three postprocedural ischemic complications occurred in two (8.7 %) of the SAH patients and in one of the elective patients (3.45%). Overall aneurysm occlusion was Raymond Roy (RR) I in 36 (69.2%), RR II in 9, and RR III in 9 cases. Follow-up imaging was available for 23 patients after an average of 147.7 (±59.6) days demonstrating RR I occlusion in 22 (95.5%) and RR II in 1 patient.

CONCLUSION

SAC with the pEGASUS-HPC stent system demonstrates rates of periprocedural safety and effectiveness that are comparable with previously reported series for stent-assisted coil embolization.

Flow diversion for compressive unruptured internal carotid artery aneurysms with neuro-ophthalmological symptoms: a systematic review and meta-analysis

BACKGROUND

Data on the safety and efficacy of flow diverters (FD) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms (NOS) are scarce and comprise mainly small case series.

METHODS

We performed a search of three databases and included series with ≥10 patients, with unruptured aneurysms of the ICA and NOS, treated with FD. Random-effects analysis of treatment results and safety was performed.

RESULTS

A total of 22 studies reporting on 594 patients were included. Pooled proportions of NOS recovery, improvement, transient and permanent worsening were: 47.4% (95% CI 35.0% to 60.1%); 74.5% (95% CI 67.9% to 80.2%); 7.1% (95% CI 3.3% to 14.7%); and 4.9% (95% CI 3.2% to 7.4%), respectively. Rates of complete recovery and improvement in patients with isolated visual symptoms were 30.6% (95% CI 12.5% to 57.7%) and 56.6% (95% CI 42.3% to 69.9%). Isolated oculomotor symptoms recovered completely in 47.8% (95% CI 29.9% to 66.3%) and improved in 78% (95% CI 69.2% to 84.9%). Morbidity occurred in 5% (95% CI 2.8% to 9%) and mortality in 3.9% (95% CI 2% to 7.5%) of patients. An increased likelihood of symptom improvement was observed when treatment was performed early (<1 month) after symptom onset (OR=11.22, 95% CI 3.9% to 32.5%).

CONCLUSION

Flow diversion promotes recovery or improvement of compressive symptoms in a large proportion of patients but is associated with significant rates of morbidity and mortality. Transient and permanent NOS worsening is not uncommon. Early treatment is of utmost importance, as it increases the likelihood of symptom improvement more than 10-fold.

A Systematic Literature Review and Meta-Analysis of the Treatment of Ruptured Intracranial Aneurysms with Hydrophilic Polymer and Phosphorylcholine-Coated Flow Diverters Under Single Antiplatelet Therapy

OBJECTIVE

Flow diverters coated with antithrombogenic substances were recently introduced and have shown encouraging results in the preclinical setting. Our aim was to analyze their clinical application in patients with ruptured intracranial aneurysms using single antiplatelet therapy (SAPT).

METHODS

We performed a PRISMA-compliant systematic review and meta-analysis covering 3 major data bases until March 2022.Two reviewers independently reviewed clinical studies for eligibility.Random-effects analysis of proportions was used to pool safety outcomes (hemorrhagic, thrombembolic, and overall complications). Studies were tested for publication bias and heterogeneity.

RESULTS

Five studies reporting 43 patients with 46 aneurysms were identified. More than 1 stent was implanted in 16%, and additional coil embolization was performed in 53.8% of patients. SAPT with one of various acetylsalicylic acid regimens was used in 86%, altogether antiplatelet protocols were variable. The pooled risks of thromboembolic (23.9%; 95% confidence interval [CI], 9.6-47.9), hemorrhagic (9.4%; 95% CI, 3.6-22.6), and overall complications (28.3%; 95% CI, 12.4-52.5) were calculated in the absence of publication bias with low to moderate study heterogeneity measures. All complications occurred in patients under acetylsalicylic acid SAPT. Adequate aneurysm occlusion was described in 65.5% of patients.few retrospective observational studies with moderate heterogeneity, encompassing a limited number of patients treated with variable SAPT regimens.

CONCLUSIONS

Flow diversion for ruptured aneurysms under SAPT with coated stents is feasible. Although the risk of hemorrhagic complications was low, thromboembolic complications occurred in a significant number of patients, all under ASA SAPT.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases

BACKGROUND

Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience.

METHODS

A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted.

RESULTS

We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis.

CONCLUSION

Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Flow Diversion for ICA Aneurysms with Compressive Neuro-Ophthalmologic Symptoms: Predictors of Morbidity, Mortality, and Incomplete Aneurysm Occlusion

BACKGROUND AND PURPOSE

Flow diversion is an effective treatment for aneurysms of the ICA with compression-related neuro-ophthalmologic symptoms, especially when treatment is initiated early after symptom onset and aneurysm occlusion is complete. However, non-negligible complication rates have been reported. Our aim was to identify risk factors for morbidity/mortality and incomplete aneurysm occlusion.

MATERIALS AND METHODS

We performed a secondary analysis of a previous publication, which included all patients treated with flow diversion for an unruptured aneurysm of the ICA with compression-related symptoms.

RESULTS

Fifty-four patients with 54 aneurysms (48 women, 88.9%; mean age, 59.2 [SD, 15.9] years; range, 21-86 years) treated with flow diversion were included. We observed morbidity and mortality rates of 7.4% and 3.7%. Increasing age (OR per decade, 3.2; 95% CI, 1.23-8.49; P = .02) and dual-antiplatelet therapy with ticagrelor (OR, 13.9; 95% CI, 1.16-165.97; P = .04) were significantly associated with morbidity/mortality. After a median follow-up of 13.3 [SD, 10.5] months, the rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 74%, 14%, and 12%. Incomplete occlusion at follow-up was less frequently observed in aneurysms treated with additional coil embolization (OR, 0.1; 95% CI, 0.01-0.86; P = .04).

CONCLUSIONS

Although a promising treatment for compressive ICA aneurysms, flow diversion carries a relevant risk for complications and incomplete aneurysm occlusion. Our results may help identify patients in which flow diversion may not be the ideal treatment method. Additional coil embolization increased the likelihood of complete aneurysm occlusion at follow-up.

Flow diversion for internal carotid artery aneurysms with compressive neuro-ophthalmologic symptoms: clinical and anatomical results in an international multicenter study

BACKGROUND

Scientific data on the safety and efficacy of flow diverter stents (FDS) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms are scarce. We studied this subject in a retrospective international multicenter series, pooling data of 9 tertiary care neurointerventional departments.

OBJECTIVE

To investigate, in a retrospective, multicentric cohort of patients presenting with visual or oculomotor symptoms attributed to a compressive carotid artery in an unruptured intracranial aneurysm, the safety and efficacy profiles of FDS, by analyzing neuro-opthalmologic symptom evolution following FDS placement, complications, and aneurysm obliteration rates.

METHODS

All patients treated since 2015 with a FDS for an unruptured aneurysm of the ICA with signs of compressive cranial nerve symptoms (CN II, III, IV, VI) were included.

RESULTS

We treated 55 patients with 55 aneurysms; 21 (38.2%) patients had oculomotor and 15 (27.3%) visual symptoms only; 19 (34.5%) presented with a combination of both. Treatment-related morbidity/mortality occurred in 7.2% and 3.6%, respectively. At last imaging follow-up (13.1±10.5 months) rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 72%, 14%, and 14%, respectively. At last clinical follow-up after 13±10.5 months, 19/51 (37.3%) patients had recovered completely and 18/51 (35.3%) had recovered at least partially from their neuro-ophthalmological symptoms. In multivariable models, a longer delay between symptom onset and treatment was associated with higher odds for incomplete recovery and lower odds for any improvement (aOR 1.03 (95% CI 1.01 to 1.07), p=0.047 and 0.04 (0-0.81), p=0.020). Incomplete recovery was independently associated with older age and fusiform aneurysms.

CONCLUSION

FDS are effective to treat patients with compressive aneurysms of the ICA causing neuro-ophthalmological symptoms, especially when treatment is initiated early after symptom onset, and aneurysm occlusion is adequate. However, serious complications are not rare.

Serum neurofilament light chain levels are associated with stroke severity and functional outcome in patients undergoing endovascular therapy for large vessel occlusion

BACKGROUND

We aimed to analyze serum neurofilament light chain (sNfL) levels in patients undergoing endovascular therapy (EVT) for anterior circulation large vessel occlusion (acLVO).

METHODS

Prospective study of consecutive patients with acLVO receiving EVT (12/2020-01/2021). sNfL was serially measured prior to and at 30-min, 6-h, 12-h, 24-h, 48-h and 7-days following EVT. ANOVA and Spearman correlation were run to assess sNfL levels (ie, absolute values) and ΔsNfL levels (ie, absolute values subtracted by baseline value) and their association with clinical (ie, NIHSS), imaging (ie, ASPECTS) surrogates of stroke severity as well as functional outcome (ie, mRS) at 90-days.

RESULTS

175 sNfL samples were retrieved from 25 patients. While there were no differences among serial sNfL levels in the first 12-h post-EVT, a constant increase was observed afterwards (maximum day 7, median: 383 [IQR, 209-907] pg/mL, p < 0.001). ΔsNfL showed a constant increase from 30-min measurement onwards peaking after 7 days (median 363.5 [IQR, 114.3-851.1] pg/mL). sNfL levels at 7 days correlated with ASPECTS post-EVT (r = -0.59, p < 0.001), NIHSS at discharge (r = -0.50, p = 0.011) and mRS at 90-days (r = 0.45, p = 0.027).

CONCLUSIONS

Serum NFL may complement established clinical and imaging predictors of treatment response and functional outcome in stroke patients undergoing EVT for acLVO.

Association of Regular Thrombus Surface Phenotype With Complete Recanalization in First-Line Contact Aspiration Thrombectomy for Basilar Artery Occlusion

Objective: To assess whether angiographic thrombus surface phenotype has an impact on efficacy of contact aspiration (CA) thrombectomy in patients with basilar artery occlusion (BAO). Methods: From January 2016 to December 2019, consecutive stroke patients with a BAO and first-line CA were analyzed in this retrospective study. We assessed baseline and imaging characteristics and treatment and clinical outcomes. We rated thrombus surface phenotype on pre-treatment digital subtraction angiography in a three-reader-consensus setting. Primary outcome was complete recanalization (modified treatment in cerebral ischemia [mTICI] 3 and arterial occlusive lesion [AOL] 3) after first-line CA without additionally stent retriever passes. Data analysis was stratified according to thrombus surface phenotype and complete first-line recanalization. Results: Seventy-eight patients met the inclusion criteria. Median age was 74 years (IQR 64-80), 64% were male, and median baseline NIHSS score was 24 (IQR 7-32). Thirty patients had a regular and 16 patients had an irregular thrombus phenotype. Thrombus surface was not assessable in 32 patients. In patients with a regular phenotype, complete recanalization was more often achieved compared to irregular and non-ratable phenotypes (50 vs. 18.8% and 21.9%; p = 0.027). Patients with a regular phenotype [odds ratio [OR] 8.3; 95% confidence interval [CI]: 1.9-35.8; p = 0.005], cardioembolic stroke (OR 12.1, 95% CI: 2.0-72.8; p = 0.007), and proximal end of the thrombus in the middle basilar artery segment (OR 5.2, 95% CI: 1.0-26.6; p = 0.046) were more likely to achieve complete recanalization after first-line CA without rescue therapy. Conclusion: The efficacy of CA may differ according to the angiographic thrombus surface phenotype in patients with BAO. A regular phenotype is associated with higher rates of complete recanalization in first-line CA. However, assessment of thrombus phenotype is frequently not feasible in BAO.

Reconstructive endovascular treatment of basilar artery fenestration aneurysms: A multi-centre experience and literature review

BACKGROUND

Data on outcome after endovascular treatment of basilar artery fenestration aneurysms (BAFAs) is limited. This study presents our multi-centre experience of BAFAs treated by different reconstructive techniques including coils, stent-assisted coiling (SAC), flow diversion and intra-saccular flow disruption with the Woven Endobridge (WEB).

METHODS

Retrospective analysis of 38 BAFAs treated endovascularly between 2003 and 2020. The primary endpoint was complete aneurysm obliteration defined as Raymond-Roy occlusion classification (RROC) I on immediate and follow-up (FU) angiography. The secondary endpoints were procedure-related complications, rate of re-treatment, and clinical outcome.

RESULTS

Endovascular treatment was feasible in 36/38 aneurysms (95%). The most frequent strategy was coiling (21/36, 58%), followed by SAC (7/36, 19%), WEB embolization (6/36, 17%) and flow diversion (2/36, 6%). A successful aneurysm occlusion (defined as RROC 1 and 2) on the final angiogram was achieved in 30/36 (83%) aneurysms including all patients presenting with baseline subarachnoid haemorrhage and 25/36 (69%) were occluded completely. Complete occlusion (RROC 1) was more frequently achieved in ruptured BAFAs (15/25, 60% v. 2/11, 18%; p = 0.031). Procedure-related complications occurred in 3/36 (8%) aneurysms. Re-treatment was executed in 12/36 (33%) aneurysms. After a median angiography FU of 38 months, 30/31 (97%) BAFAs were occluded successfully and 25/31 (81%) showed complete occlusion.

CONCLUSION

Reconstructive endovascular treatment of BAFAs is technically feasible with a good safety profile. Although in some cases re-treatment was necessary, a high rate of final aneurysm occlusion was achieved.

Mechanical thrombectomy in acute ischaemic stroke patients with pre-interventional intracranial haemorrhage following intravenous thrombolysis

Background

Data on outcome of endovascular treatment in patients with acute ischaemic stroke due to large vessel occlusion suffering from intravenous thrombolysis-associated intracranial haemorrhage prior to mechanical thrombectomy remain scarce. Addressing this subject, we report our multicentre experience.

Methods

A retrospective analysis of consecutive acute ischaemic stroke patients treated with mechanical thrombectomy due to large vessel occlusion despite the pre-interventional occurrence of intravenous thrombolysis-associated intracranial haemorrhage was performed at five tertiary care centres between January 2010–September 2020. Baseline demographics, aetiology of stroke and intracranial haemorrhage, angiographic outcome assessed by the Thrombolysis in Cerebral Infarction score and clinical outcome evaluated by the modified Rankin Scale at 90 days were recorded.

Results

In total, six patients were included in the study. Five individuals demonstrated cerebral intraparenchymal haemorrhage on pre-interventional imaging; in one patient additional subdural haematoma was observed and one patient suffered from isolated subarachnoid haemorrhage. All patients except one were treated by the ‘drip-and-ship’ paradigm. Successful reperfusion was achieved in 4/6 (67%) individuals. In 5/6 (83%) patients, the pre-interventional intracranial haemorrhage had aggravated in post-interventional computed tomography with space-occupying effect. Overall, five patients had died during the hospital stay. The clinical outcome of the survivor was modified Rankin Scale=4 at 90 days follow-up.

Conclusion

Mechanical thrombectomy in patients with intravenous thrombolysis-associated intracranial haemorrhage is technically feasible. The clinical outcome of this subgroup of stroke patients, however, appears to be devastating with high mortality and only carefully selected patients might benefit from endovascular treatment.

Fast Stent Retrieval during Mechanical Thrombectomy Improves Recanalization in Patients with the Negative Susceptibility Vessel Sign

BACKGROUND AND PURPOSE

In acute ischemic stroke, the negative susceptibility vessel sign on T2*-weighted images traditionally highlights fibrin-rich clots, which are particularly challenging to remove. In vitro, fast stent retrieval improves fibrin-rich clot extraction. We aimed to evaluate whether the speed of stent retrieval influences the recanalization and clinical outcome of patients presenting with the negative susceptibility vessel sign.

MATERIALS AND METHODS

Patients were identified from a registry of patients with ischemic stroke receiving mechanical thrombectomy between January 2016 and January 2020. Inclusion criteria were the following: 1) acute ischemic stroke caused by an isolated occlusion of the anterior circulation involving the MCA (Internal Carotid Artery-L, M1, M2) within 8 hours of symptom onset; 2) a negative susceptibility vessel sign on prethrombectomy T2*-weighted images; and 3) treatment with a combined technique (stent retriever + contact aspiration). Patients were dichotomized according to retrieval speed (fast versus slow). The primary outcome was the first-pass recanalization rate.

RESULTS

Of 68 patients who met inclusion criteria, 31 (45.6%) were treated with fast retrieval. Patients receiving a fast retrieval had greater odds of first-pass complete (relative risk and 95% confidence interval [RR 95% CI], 4.30 [1.80-10.24]), near-complete (RR 95% CI, 3.24 [1.57-6.68]), and successful (RR 95% CI, 2.60 [1.53-4.43]) recanalization as well as greater odds of final complete (RR 95% CI, 4.18 [1.93-9.04]), near-complete (RR 95% CI, 2.75 [1.55-4.85]), and successful (RR 95% CI, 1.52 [1.14-2.03]) recanalization. No significant statistical differences in procedure-related serious adverse events, distal embolization, or symptomatic intracranial hemorrhage were reported. No differences were noted in terms of functional independence (RR 95% CI, 1.01 [0.53-1.93]) and all-cause mortality (RR 95% CI, 0.90 [0.35-2.30]) at 90 days.

CONCLUSIONS

A fast stent retrieval during mechanical thrombectomy is safe and improves the retrieval of clots with the negative susceptibility vessel sign.

FLAIR Vascular Hyperintensities Indicate Slow Poststenotic Blood Flow in ICA Stenosis

PURPOSE

Occlusion or significant stenosis of the internal carotid artery (ICA) in the cervical segment is commonly associated with a poststenotic decrease in the downstream blood flow and perfusion. Fluid attenuated inversion recovery (FLAIR) vascular hyperintensities (FVH) are a phenomenon that represents slow arterial blood flow. In this study, we investigated the frequency and extent of FVH in the distal ICA in patients with proximal ICA stenosis.

METHODS

We analyzed the magnetic resonance imaging (MRI) findings in 51 patients with a total of 60 cervical ICA stenoses with special focus on the frequency and extent of FVH in the area of the petrous segment of the ICA on FLAIR images and correlated these with Doppler/duplex sonography results.

RESULTS

In 46 (76.7%) patients with ICA stenosis, FVH could be detected in the petrous segment of the ICA: in 19 (41.3%) patients a thin hyperintense rim near the vessel wall (grade 1), in 24 (52.2%) patients a strong hyperintense rim near the vessel wall (grade 2), and in 3 (6.5%) patients a hyperintense filling of the entire lumen (grade 3) was observed. The extent of FVH in the ICA in the petrous segment showed a high negative correlation with the poststenotic flow velocity (Spearman correlation, R = -0.75, p < 0.001), and moderate correlation with the degree of ICA stenosis (Spearman correlation, R = 0.51, p< 0.001).

CONCLUSION

An FVH in the petrous ICA is commonly seen among patients with steno-occlusive disease in proximal ICA and could therefore be useful to recognize a proximal ICA stenosis even on FLAIR images.

Fast Stent Retrieval Improves Recanalization Rates of Thrombectomy: Experimental Study on Different Thrombi

BACKGROUND AND PURPOSE

About 20% of patients with acute ischemic stroke due to large-artery occlusion do not achieve recanalization with mechanical thrombectomy. We aimed to determine whether the speed of retrieval of the stent retriever influences the efficacy in removing different clot types.

MATERIALS AND METHODS

Sixty mechanical thrombectomies were performed using an in vitro pulsatile cerebrovascular circulation model with controlled pressure and flow rate. Experiments were dichotomized into fast and slow retrieval using a wedging technique, in which the stent retriever and distal catheter are retrieved together. We used 3 different clot types: erythrocyte-rich, fibrin-rich, and friable clots. Primary end points were complete (TICI 3) and successful (TICI 2b-3) recanalizations. Secondary measures were distal and new territory embolizations.

RESULTS

Fast retrieval was more frequently associated with complete (RR = 1.83; 95% CI, 1.12-2.99) and successful recanalization (RR = 1.50; 95% CI, 1.03-2.19) than slow retrieval, without a difference in distal embolization (RR = 0.75; 95% CI, 0.29-1.90). There were no emboli in a new territory. The advantage of fast retrieval over slow retrieval differed according to the clot composition, with a stronger effect with fibrin-rich clots with regard to complete (RR = 4.00; 95% CI, 1.11-14.35; Pint = .04) and successful (Pint = .10) recanalization.

CONCLUSIONS

In our experimental model, a fast removal improved recanalization rates of mechanical thrombectomy, especially in the case of fibrin-rich clots. An in vivo confirmation is warranted to see whether our findings can have an impact in clinical practice.

Mechanical Thrombectomy in Ischemic Stroke Patients With Alberta Stroke Program Early Computed Tomography Score 0-5

Supplemental Digital Content is available in the text.

Background and Purpose—

If anterior circulation large vessel occlusion acute ischemic stroke patients presenting with ASPECTS 0–5 (Alberta Stroke Program Early CT Score) should be treated with mechanical thrombectomy remains unclear. Purpose of this study was to report on the outcome of patients with ASPECTS 0–5 treated with mechanical thrombectomy and to provide data regarding the effect of successful reperfusion on clinical outcomes and safety measures in these patients.

Methods—

Multicenter, pooled analysis of 7 institutional prospective registries: Bernese-European Registry for Ischemic Stroke Patients Treated Outside Current Guidelines With Neurothrombectomy Devices Using the SOLITAIRE FR With the Intention for Thrombectomy (Clinical Trial Registration—URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064). Primary outcome was defined as modified Rankin Scale 0–3 at day 90 (favorable outcome). Secondary outcomes included rates of day 90 modified Rankin Scale 0–2 (functional independence), day 90 mortality and occurrence of symptomatic intracerebral hemorrhage. Multivariable logistic regression analyses were performed to assess the association of successful reperfusion with clinical outcomes. Outputs are displayed as adjusted Odds Ratios (aOR) and 95% CI.

Results—

Two hundred thirty-seven of 2046 patients included in this registry presented with anterior circulation large vessel occlusion and ASPECTS 0–5. In this subgroup, the overall rates of favorable outcome and mortality at day 90 were 40.1% and 40.9%. Achieving successful reperfusion was independently associated with favorable outcome (aOR, 5.534; 95% CI, 2.363–12.961), functional independence (aOR, 5.583; 95% CI, 1.964–15.873), reduced mortality (aOR, 0.180; 95% CI, 0.083–0.390), and lower rates of symptomatic intracerebral hemorrhage (aOR, 0.235; 95% CI, 0.062–0.887). The mortality-reducing effect remained in patients with ASPECTS 0–4 (aOR, 0.167; 95% CI, 0.056–0.499). Sensitivity analyses did not change the primary results.

Conclusions—

In patients presenting with ASPECTS 0–5, who were treated with mechanical thrombectomy, successful reperfusion was beneficial without increasing the risk of symptomatic intracerebral hemorrhage. Although the results do not allow for general treatment recommendations, formal testing of mechanical thrombectomy versus best medical treatment in these patients in a randomized controlled trial is warranted.

Flow diversion treatment of complex bifurcation aneurysms beyond the circle of Willis: complications, aneurysm sac occlusion, reabsorption, recurrence, and jailed branch modification at follow-up

OBJECTIVE

The purpose of this study is to present the authors’ medium-term results, with special emphasis on complications, occlusion rate of the aneurysm sac (digital subtraction angiography [DSA] and MRI), and the fate of cortical branches and perforating arteries covered (“jailed”) by the flow diverter (FD) stent.

METHODS

Between January 2010 and September 2017, 29 patients (14 female) with 30 aneurysms were treated with an FD stent. Twenty-one aneurysms were at the middle cerebral artery bifurcation, 8 were in the anterior communicating artery region, and 1 was a pericallosal artery bifurcation. Thirty-five cortical branches were covered. A single FD stent was used in all patients. Symptomatic and asymptomatic periprocedural and delayed complications were reported. DSA and MRI controls were analyzed to evaluate modification of the aneurysm sac and jailed branches.

RESULTS

Permanent morbidity was 3.4% (1/29), due to a jailed branch occlusion, with a modified Rankin Scale (mRS) score of 2 at the last follow-up. Mortality and permanent complication with poor prognosis (mRS score > 2) rates were 0%. The mean follow-up time for DSA and MRI (mean ± SD) was 21 ± 14.5 months (range 3–66 months) and 19 ± 16 months (range 3–41 months), respectively. The mean time to aneurysm sac occlusion (available for 24 patients), including stable remodeling, was 11.8 ± 6 months (median 13, range 3–27 months). The overall occlusion rate was 82.1% (23/28), and it was 91.7% (22/24) in the group of patients with at least 2 DSA control sequences. One recanalization occurred at 41 months posttreatment. At the time of publication, at the latest follow-up, 7 (20%) of 35 covered branches were occluded, 18 (51.4%) showed a decreased caliber, and the remaining 10 (28.5%) were unchanged. MRI T2-weighted sequences showed complete sac reabsorption in 7/29 aneurysms (24.1%), and the remaining lesions were either smaller (55.2%) or unchanged (17.2%). MRI revealed asymptomatic and symptomatic ischemic events in perforator territories in 7/28 (25%) and 4/28 (14.3%) patients, respectively, which were reversible within 24 hours.

CONCLUSIONS

Flow diversion of bifurcation aneurysms is feasible, with low rates of permanent morbidity and mortality and high occlusion rates; however, recurrence may occur. Caliber reduction and asymptomatic occlusion of covered cortical branches as well as silent perforator stroke are common. Ischemic complications may occur with no identified predictable factors. MRI controls should be required in all patients to evaluate silent ischemic lesions and aneurysm sac reabsorption over time.

Mechanical thrombectomy for basilar artery occlusion: efficacy, outcomes, and futile recanalization in comparison with the anterior circulation

BACKGROUND

Performing mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based.

OBJECTIVE

To compare patients' outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between BAO and anterior circulation large vessel occlusion (ACLVO) MT.

METHODS

In the multicenter BEYOND-SWIFT registry (NCT03496064), univariate and multivariate (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI) outcome comparisons between BAO (N=165) and ACLVO (N=1574) were performed. The primary outcome was favorable outcome at 90 days (modified Rankin Scale, mRS 0-2). Secondary outcome included mortality, symptomatic intracranial hemorrhage (sICH) and FR. The relative merits of achieving successful recanalization between ACLVO and BAO were evaluated with interaction terms.

RESULTS

MT in BAO was more often technically effective and equally safe in regards to mortality and sICH when compared to ACLVO. When adjusting for baseline differences, there was no significant difference between BAO vs ACLVO regarding rates of favorable outcome (aOR 0.986, 95%-CI 0.553 - 1.758). However, BAO were associated with increased rates of FR (aOR 2.146, 95%-CI 1.267 - 3.633). Predictors for FR were age, stroke severity, maneuver count and intracranial stenting. No significant heterogeneity on the relative merits of achieving successful recanalization on several outcome parameters were observed when comparing BAO and ACLVO.

CONCLUSIONS

In selected patients, similar outcomes can be achieved in BAO and ACLVO patients treated with MT. Randomized controlled trials comparing patient selection and interventional strategies seem warranted to avoid FR.

TRIAL REGISTRATION NUMBER

NCT03496064.

Outcome, efficacy and safety of endovascular thrombectomy in ischaemic stroke according to time to reperfusion: data from a multicentre registry

BACKGROUND AND PURPOSE

In acute ischaemic stroke (AIS) of the anterior circulation (AC) treated with mechanical thrombectomy (MT), data point to a decline of treatment effect with increasing time from symptom onset to treatment. However, the magnitude of the decline will depend on the clinical setting and imaging selection used. The aims of this study were (1) to evaluate the clinical effect of time to reperfusion (TTR); and (2) to assess the safety and technical efficacy of MT according to strata of TTR.

METHODS

Using the retrospective multicentre BEYOND-SWIFT registry data (ClinicalTrials.gov identifier: NCT03496064), we compared safety and efficacy of MT in 1461 patients between TTR strata of 0-180 min (n = 192), 180-360 min (n = 876) and >360 min (n = 393). Clinical effect of TTR was evaluated using multivariable logistic regression analyses adjusting for pre-specified confounders [adjusted odds ratios (aOR) and 95% confidence intervals (95% CI)]. Primary outcome was good functional outcome (modified Rankin Scale: mRS 0-2) at day 90.

RESULTS

Every hour delay in TTR was a significant factor related to mRS 0-2 (aOR 0.933, 95% CI 0.887-0.981) with an estimated 1.5% decreased probability of good functional outcome per hour delay of reperfusion, and mRS 0-1 (aOR 0.929, 95% CI 0.877-0.985). Patients with late TTR had lower rates of successful and excellent reperfusion, higher complication rates and number of passes.

CONCLUSIONS

TTR is an independent factor related to long-term functional outcome. With increasing TTR, interventional procedures become technically less effective. Efforts should be made to shorten TTR through optimized prehospital and in-hospital pathways.

Aneurysm Characteristics, Study Population, and Endovascular Techniques for the Treatment of Intracranial Aneurysms in a Large, Prospective, Multicenter Cohort: Results of the Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm Study

BACKGROUND AND PURPOSE

The Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm (ARETA) prospective study aims to determine factors predicting recurrence after endovascular treatment for intracranial aneurysms. In this publication, we review endovascular techniques and present the study population. Characteristics of treated and untreated unruptured aneurysms were analyzed.

MATERIALS AND METHODS

Sixteen neurointerventional departments prospectively enrolled patients treated for ruptured and unruptured intracranial aneurysms between December 2013 and May 2015. Patient demographics, aneurysm characteristics, and endovascular techniques were recorded.

RESULTS

A total of 1289 patients with 1761 intracranial aneurysms, 835 (47.4%) ruptured, were enrolled. Of these, 1359 intracranial aneurysms were treated by endovascular means. Ruptured intracranial aneurysms were treated by coiling and balloon-assisted coiling in 97.8% of cases. In unruptured intracranial aneurysms, the rates of flow diversion, flow disruption, and stent-assisted coiling were 11.6%, 6.9%, and 7.8%, respectively. Rupture status and aneurysm location, neck diameter, and sac size significantly influenced the chosen technique. Treated unruptured intracranial aneurysms, compared with untreated counterparts, had larger aneurysm sacs (7.6 ± 4.0 versus 3.4 ± 2.0 mm; P < 0.001) and neck dimensions (4.1 ± 2.2 versus 2.4 ± 1.3 mm; P < 0.001) and more frequently an irregular form (84.6% versus 44.4%; P < 0.001). Also, its location influenced whether an unruptured intracranial aneurysm was treated.

CONCLUSIONS

Our study provides an overview of current neurointerventional practice in the ARETA cohort. The technique choice was influenced by aneurysm morphology, location, and rupture status. Flow diversion, flow disruption, and stent-assisted coiling were commonly used in unruptured intracranial aneurysms, while most ruptured intracranial aneurysms were treated with coiling and balloon-assisted coiling.

Clinical effect of successful reperfusion in patients presenting with NIHSS < 8: data from the BEYOND-SWIFT registry

BACKGROUND AND PURPOSE

If patients presenting with large vessel occlusions (LVO) and mild symptoms should be treated with endvoascular treatment (EVT) remains unclear. Aims of this study were (1) assessing the safety and technical efficacy of EVT in patients with NIHSS < 8 as opposed to a comparison group of patients presenting with NIHSS ≥ 8 and (2) evaluation of the clinical effect of reperfusion in patients with NIHSS < 8.

METHODS

Patients included into the retrospective multicenter BEYOND-SWIFT registry (NCT03496064) were analyzed. Clinical effect of achieving successful reperfusion (defined as modified Thrombolysis in Cerebral Infarction grade 2b/3) in patients presenting with NIHSS < 8 (N = 193) was evaluated using multivariable logistic regression analyses (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI). Primary outcome was excellent functional outcome (modified Rankin Scale, mRS 0-1) at day 90. Safety and efficacy of mechanical thrombectomy in patients with NIHSS < 8 was compared to patients presenting with NIHSS ≥ 8 (N = 1423).

RESULTS

Among patients with NIHSS < 8 (N = 193, 77/193, 39.9% receiving pre-interventional IV-tPA), successful reperfusion was significantly related to mRS 0-1 (aOR 3.217, 95%-CI 1.174-8.816) and reduced the chances of non-hemorrhagic neurological worsening (aOR 0.194, 95%-CI 0.050-0.756) after adjusting for prespecified confounders. In interaction analyses, the relative merits of achieving successful reperfusion were mostly comparable between patients presenting with NIHSS < 8 and NIHSS ≥ 8 as evidenced by non-significantly different aOR. Interventional safety and efficacy metrics were similar between patients with NIHSS < 8 and NIHSS ≥ 8.

CONCLUSIONS

Achieving successful reperfusion is beneficial in patients with persisting LVO presenting with NIHSS < 8 and reduces the risk of non-hemorrhagic neurological worsening.

Can early neurological improvement after mechanical thrombectomy be used as a surrogate for final stroke outcome?

Background and purpose

We aimed to identify the best definition of early neurological improvement (ENI) at 2 and 24 hours after mechanical thrombectomy (MT) and determine its ability to predict a good functional outcome at 3 months.

Methods

This retrospective analysis was based on a prospectively collected registry of patients treated by MT for ischemic stroke from May 2010 to March 2017. We included patients treated with stent-retrievers with National Institute of Health Stroke Scale (NIHSS) score before treatment and at 2 and/or 24 hours after treatment and modified Rankin Score (mRS) at 3 months. Receiver operating characteristic curve analysis was performed to estimate optimal thresholds for ENI at 2 and 24 hours. The relationship between optimal ENI definitions and good outcome at 3 months (mRS 0–2) was assessed by logistic regression.

Results

The analysis included 246 patients. At 2 hours, the optimal threshold to predict a good outcome at 3 months was improvementin the NIHSS score of >1 point (AUC 0.83,95% CI 0.77 to 0.87), with sensitivity and specificity 78.3% (62.2–85.7%) and 84.6% (77.2–90.3%), respectively, and OR 12.67 (95% CI 4.69 to 31.10, p<0.0001). At 24 hours, the optimal threshold was an improvementin the NIHSS score of >4 points (AUC 0.93, 95% CI 0.89 to 0.96), with sensitivity and specificity 93.8% (87.7–97.5%) and 83.2% (75.7–89.2%), respectively, and OR 391.32 (95% CI 44.43 to 3448.35, p<0.0001).

Conclusions

ENI 24 hours after thrombectomy appears to be a straightforward surrogate of long-term endpoints and may have value in future research.

Mechanical Thrombectomy for Tandem Occlusions of the Internal Carotid Artery-Results of a Conservative Approach for the Extracranial Lesion

Background: Mechanical thrombectomy (MT) is of clinical benefit for patients with extracranial-intracranial tandem lesions of anterior circulation. However, the optimal approach to the cervical lesion of the internal carotid artery (ICA) during MT has yet to be established. Data on a conservative approach for the proximal lesion during the acute phase are scarce.

Methods: A retrospective study on an institutional, prospective database was conducted. We included patients with anterior circulation stroke presenting with a tandem lesion that was approached conservatively during MT.

Results: Thirty-five 35 patients were included, of whom 25 (71.4%) had an atheromatous ICA lesion and 10 (28.6%) a dissection. Despite implementing a conservative strategy, acute percutaneous transluminal angioplasty (PTA) and/or stenting was necessary in 8 (22.9%) and 3 patients (8.6%), respectively. Of 27 surviving patients, 7 (25.9%) underwent delayed treatment of the ICA lesion. No new embolic events occurred between MT and delayed treatment. A favorable clinical outcome (mRS ≤ 2) was achieved in 15/35 patients (45.7%) and was associated with higher baseline ASPECTS (OR 1.62, 95% CI 1.08–2.45, p = 0.002) and successful recanalization (OR 9.39, 95% CI 1.92–45.80, p = 0.0005). Successful recanalization (TICI ≥ 2B) itself was observed in 54.3% of patients and was more likely with acute treatment of the proximal ICA lesion (OR 6.3, 95% CI 11–35.67, p = 0.03) and, more importantly, by the use of distal access catheters (OR 16.25, 95% CI 3.06–86.41, p = 0.0001).

Conclusion: A conservative approach for ICA lesions during MT is feasible and offers favorable outcomes and successful recanalization for a significant proportion of patients. However, acute treatment of the cervical lesion is often necessary (31.4%) to make the distal occlusion accessible. Clinical outcome is influenced by the size of the baseline ischemic core and by successful recanalization; the latter is strongly favored by the use of distal access catheters to pass the proximal lesion. The fact that acute treatment of the ICA lesion favored intracranial recanalization but had no effect on clinical outcome is probably due to sample size, emphasizing the need for large scale, randomized studies to determine the optimal treatment strategy for this pathology.

Hilar en bloc resection for hilar cholangiocarcinoma in patients with limited liver capacities-preserving parts of liver segment 4

Background

A right trisectionectomy with portal vein resection represents the conventional approach for hilar cholangiocarcinoma. Here, we present a technical modification of hilar en bloc resection in order to increase the remnant volume by partially preserving liver segment 4.

Methods

The caudal parenchymal dissection line starts centrally between the left lateral and left medial segments. Cranially, the resection line switches to the right towards Cantlie's line and turns again upwards perpendicularly. Hence, segment 4a and subtotal segment 4b are partially preserved by this novel technique. The left hepatic duct is dissected at the segmental ramification and reconstruction is performed as a single hepaticojejunostomy. The feasibility of the novel parenchyma-sparing approach for hilar cholangiocarcinoma was proven in a case series and medical records were reviewed retrospectively.

Results

Ten patients (6 male, 4 female) underwent segment 4 partially preserving right trisectionectomy for hilar cholangiocarcinoma. Estimated future liver remnant volume was significantly increased (FLRV 38.3%), when compared to standard right trisectionectomy (FLRV 23.9%; p < 0.01). Three of 10 liver resections were associated with major surgical complications (≥IIIb; n = 3); categorized according to the Dindo-Clavien classification. No patient died due to complications associated with postoperatively impaired liver function. Tumor-free margins could be achieved in 8 patients while median overall survival and disease-free survival were 547 and 367 days, respectively.

Conclusion

This novel parenchyma-sparing modification of hilar en bloc resection by partially preserving segment 4 allows to safely increase the remnant liver volume without neglecting principles of local radicality.

Treatment of recurrent aneurysms using the Woven EndoBridge (WEB): anatomical and clinical results

Background

The safety and efficacy of the Woven EndoBridge (WEB) for the treatment of naïve intracranial aneurysms has been confirmed.

Purpose

To analyze the safety and efficacy of the WEB in the treatment of recurrent aneurysms.

Methods

Anatomical and clinical results in consecutive patients with a recurrent aneurysm, who were treated using the WEB device in two French neurointerventional centers, were evaluated.

Results

Seventeen patients with 17 aneurysms were included. Treatment was feasible in 16 patients. In seven patients (41.2%), ancillary devices were used. Permanent morbidity due to a thromboembolic complication occurred in one patient (5.9%). There was no mortality. Follow-up angiographic studies were available for 15 patients after a mean of 12.1±6.1 months. Rates of complete occlusion, neck remnant, and aneurysm remnant were 33.3%, 40.0%, and 26.7%, respectively.

Conclusions

Treatment of recurrent aneurysms using the WEB device may be reasonably safe and effective.

Techniques for endovascular treatment of acute ischemic stroke

Early recanalization of occluded vessels in patients with acute ischemic stroke (AIS) by either intravenous thrombolysis (IVT) or endovascular revascularization has been shown to be associated with improved clinical outcomes and reduced mortality. Since the initial report regarding endovascular treatment (EVT) of AIS in 1983, endovascular techniques have been tremendously improved, advancing from intra-arterial administration of thrombolytic drugs to stent retrievers. IVT has been evaluated in several large randomized trials and has been shown to improve clinical outcomes at 90 days if treatment was initiated within 3h of stroke onset, while its benefit at 3-4.5h was subsequently demonstrated in the European Cooperative Acute Stroke Study (ECASS) III. Thus, EVT had to be evaluated against IVT. The first randomized controlled trials (RCTs) were published in 2013, and demonstrated no major differences between IVT and EVT for AIS, although these trials had important limitations. The positive results of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke (MR CLEAN) in the Netherlands, followed by five other positive RCTs, finally established the efficacy of mechanical thrombectomy (MT) with stent retrievers (also called 'stentrievers') in AIS due to large vessel occlusion within 6h of stroke onset. Currently, the European and US guidelines recommend MT with stent retrievers as a first-line treatment in the management of AIS. The recent publication of the DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake-Up and Late-Presenting Strokes Undergoing Neurointervention (DAWN) trial is expected to lead to extension of the time window for patients carefully selected by imaging. Thus, optimizing the selection of patients as well as the EVT procedures and techniques used is still an important goal to be evaluated in further trials.

FLAIR vascular hyperintensities and 4D MR angiograms for the estimation of collateral blood flow in anterior cerebral artery ischemia

PURPOSE

To assess FLAIR vascular hyperintensities (FVH) and dynamic (4D) angiograms derived from perfusion raw data as proposed magnetic resonance (MR) imaging markers of leptomeningeal collateral circulation in patients with ischemia in the territory of the anterior cerebral artery (ACA).

METHODS

Forty patients from two tertiary care university hospitals were included. Infarct volumes and perfusion deficits were manually measured on DWI images and TTP maps, respectively. FVH and collateral flow on 4D MR angiograms were assessed and graded as previously specified.

RESULTS

Forty-one hemispheres were affected. Mean DWI lesion volume was 8.2 (± 13.9; range 0-76.9) ml, mean TTP lesion volume was 24.5 (± 17.2, range 0-76.7) ml. FVH were observed in 26/41 (63.4%) hemispheres. Significant correlations were detected between FVH and TTP lesion volume (ρ = 0.4; P<0.01) absolute (ρ = 0.37; P<0.05) and relative mismatch volume (ρ = 0.35; P<0.05). The modified ASITN/SIR score correlated inversely with DWI lesion volume (ρ = -0.58; P<0.01) and positively with relative mismatch (ρ = 0.29; P< 0.05). ANOVA of the ASITN/SIR score revealed significant inter-group differences for DWI (P<0.001) and TTP lesion volumes (P<0.05). No correlation was observed between FVH scores and modified ASITH/SIR scores (ρ = -0.16; P = 0.32).

CONCLUSIONS

FVH and flow patterns on 4D MR angiograms are markers of perfusion deficits and tissue at risk. As both methods did not show a correlation between each other, they seem to provide complimentary instead of redundant information. Previously shown evidence for the meaning of these specific MR signs in internal carotid and middle cerebral artery stroke seems to be transferrable to ischemic stroke in the ACA territory.

Correlations Between DCE MRI and Histopathological Parameters in Head and Neck Squamous Cell Carcinoma

BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) can characterize perfusion and vascularization of tissues. DCE MRI parameters can differentiate between malignant and benign lesions and predict tumor grading. The purpose of this study was to correlate DCE MRI findings and various histopathological parameters in head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Sixteen patients with histologically proven HNSCC (11 cases primary tumors and in 5 patients with local tumor recurrence) were included in the study. DCE imaging was performed in all cases and the following parameters were estimated: K^trans, V_e, K_ep, and iAUC. The tumor proliferation index was estimated on Ki 67 antigen stained specimens. Microvessel density parameters (stained vessel area, total vessel area, number of vessels, and mean vessel diameter) were estimated on CD31 antigen stained specimens. Spearman's non-parametric rank sum correlation coefficients were calculated between DCE and different histopathological parameters. RESULTS: The mean values of DCE perfusion parameters were as follows: K^trans 0.189 ± 0.056 min⁻¹, K_ep 0.390 ± 0.160 min⁻¹, V_e 0.548 ± 0.119%, and iAUC 22.40 ± 12.57. Significant correlations were observed between K_ep and stained vessel areas (r = 0.51, P = .041) and total vessel areas (r = 0.5118, P = .043); between V_e and mean vessel diameter (r = −0.59, P = .017). Cell count had a tendency to correlate with V_e (r = −0.48, P = .058). In an analysis of the primary HNSCC only, a significant inverse correlation between K^trans and KI 67 was identified (r = −0.62, P = .041). Our analysis showed significant correlations between DCE parameters and histopathological findings in HNSCC.

Diffusion-Weighted MRI Reflects Proliferative Activity in Primary CNS Lymphoma

Purpose

To investigate if apparent diffusion coefficient (ADC) values within primary central nervous system lymphoma correlate with cellularity and proliferative activity in corresponding histological samples.

Materials and Methods

Echo-planar diffusion-weighted magnetic resonance images obtained from 21 patients with primary central nervous system lymphoma were reviewed retrospectively. Regions of interest were drawn on ADC maps corresponding to the contrast enhancing parts of the tumors. Biopsies from all 21 patients were histologically analyzed. Nuclei count, total nuclei area and average nuclei area were measured. The proliferation index was estimated as Ki-67 positive nuclei divided by total number of nuclei. Correlations of ADC values and histopathologic parameters were determined statistically.

Results

Ki-67 staining revealed a statistically significant correlation with ADCmin (r = -0.454, p = 0.038), ADCmean (r = -0.546, p = 0.010) and ADCmax (r = -0.515, p = 0.017). Furthermore, ADCmean correlated in a statistically significant manner with total nucleic area (r = -0.500, p = 0.021).

Conclusion

Low ADCmin, ADCmean and ADCmax values reflect a high proliferative activity of primary cental nervous system lymphoma. Low ADCmean values—in concordance with several previously published studies—indicate an increased cellularity within the tumor.

Signal Intensities in Preoperative MRI Do Not Reflect Proliferative Activity in Meningioma

BACKGROUND

Identification of high-grade meningiomas in preoperative magnetic resonance imaging (MRI) is important for optimized surgical strategy and best possible resection. Numerous studies investigated subjectively determined morphological features as predictors of tumor biology in meningiomas. The aim of this study was to identify the predictive value of more reliable, quantitatively measured signal intensities in MRI for differentiation of high- and low-grade meningiomas and identification of meningiomas with high proliferation rates, respectively.

PATIENTS AND METHODS

Sixty-six patients (56 World Health Organization [WHO] grade I, 9 WHO grade II, and 1 WHO grade I) were included in the study. Preoperative MRI signal intensities (fluid-attenuated inversion recovery [FLAIR], T1 precontrast, and T1 postcontrast as genuine and normalized values) were correlated with Ki-67 expression in tissue sections of resected meningiomas. Differences between the groups (analysis of variance) and Spearman rho correlation were computed using SPSS 22.

RESULTS

Mean values of genuine signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 323.9 ± 59, 332.8 ± 67.9, and 768.5 ± 165.3. Mean values of normalized (to the contralateral white matter) signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 1.5 ± 0.3, 0.8 ± 0.1, and 1.9 ± 0.4. There was no significant correlation between MRI signal intensities and WHO grade or Ki-67 expression. Signal intensities did not differ significantly between WHO grade I and II/III meningiomas. Ki-67 expression was significantly increased in high-grade meningiomas compared with low-grade meningiomas (P < 0.01). Objectively measured values of MRI signal intensities (FLAIR, T1 precontrast, and T1 postcontrast enhancement) did not distinguish between high-grade and low-grade meningiomas. Furthermore, there was no association between MRI signal intensities and Ki-67 expression representing proliferative activity.

Simultaneous (18)F-FDG-PET/MRI: Associations between diffusion, glucose metabolism and histopathological parameters in patients with head and neck squamous cell carcinoma

OBJECTIVES

To analyze possible associations between functional simultaneous (18)F-FDG-PET/MR imaging parameters and histopathological parameters in head and neck squamous cell carcinoma (HNSCC).

MATERIAL AND METHODS

11 patients (2 female, 9 male; mean age 56.0years) with biopsy-proven primary HNSCC underwent simultaneous (18)F-FDG-PET/MRI with a dedicated head and neck protocol including diffusion weighted imaging. For each tumor, glucose metabolism was estimated with standardized uptake values (SUV) and diffusion restriction was calculated using apparent diffusion coefficients (ADC). The tumor proliferation index was estimated on Ki 67 antigen stained specimens. Cell count, total nucleic area, and average nucleic area were estimated in each case. Pearson's correlation coefficient was used to analyze possible associations between the estimated parameters.

RESULTS

The mean SUVmax value was 24.41±6.51, and SUVmean value 15.01±4.07. Mean values (×10(-3)mm(2)s(-1)) of ADC parameters were as follows: ADCmin: 0.65±0.20; ADCmean: 1.28±0.18; and ADCmax: 2.16±0.35. Histopathological analysis identified the following results: cell count 1069.82±388.66, total nucleic area 150771.09±61177.12μm(2), average nucleic area 142.90±57.27μm(2) and proliferation index 49.09±22.67%. ADCmean correlated with Ki 67 level (r=-0.728, p=0.011) and total nucleic area (r=-0.691, p=0.019) and tended to correlate with average nucleic area (r=-0.527, p=0.096). ADCmax correlated with Ki 67 level (r=-0.633, p=0.036). SUVmax also tended to correlate with average nucleic area (r=0.573, p=0.066). Combined parameter SUVmax/ADCmin correlated with average nucleic area (r=0.627, p=0.039).

CONCLUSION

ADC and SUV values showed significant correlations with different histopathological parameters and can be used as biological markers in HNSCC.