True First-Pass Effect.

Background and Purpose- It has been hypothesized that in stroke patients, complete reperfusion (modified Thrombolysis in Cerebral Infarction; mTICI 3) after a single thrombectomy pass is a predictor for favorable outcome (modified Rankin Scale score, 0-2), but a true first-pass effect defined as improved clinical outcome after complete reperfusion with one versus multiple passes has not yet been specifically addressed in the literature. Methods- We compared clinical outcome of 164 consecutive patients with occlusions in the anterior circulation and known symptom onset, in whom we achieved complete reperfusion (mTICI 3), depending on whether complete reperfusion was achieved after a single thrombectomy pass (n=62) or multiple thrombectomy passes (n=102). To adjust for confounding factors such as prolonged time spans between symptom onset and reperfusion, additional administration of intra-arterial thrombolysis, and clot localization, we also compared clinical outcome of our first-pass group with a matched cohort (n=54) and a superselective subgroup of first-pass patients (only M1 occlusions, no additional intra-arterial thrombolysis; n=46) with its matched cohort (n=24). Results- Multivariable analysis of our cohort of 164 nonmatched patients revealed that there was a significant association between first-pass complete reperfusion and favorable clinical outcome (P=0.013). This was confirmed in our case-control analyses (P=0.010 and P=0.042). In our matched cohorts, favorable clinical outcome was seen almost twice as often if complete reperfusion was achieved after one pass (62% and 67% versus 36% and 37%), and odds for favorable outcome were 2.4 to 3.2× higher (CIs, 1.1-4.8 and 1.0-9.9). Conclusions- First-pass complete reperfusion is an independent factor for favorable outcome and should be aimed for in mechanical thrombectomy.

Development of a cluster-like headache after a stent-assisted implantation of an endovascular WEB device.

After interdisciplinary consent, a male patient in his 50s received endovascular treatment of an innocent supraophthalmic aneurysm of the internal carotid artery with a WEB (woven endo bridge) device and stenting. In the medical history, a migraine with aura was reported. A week after intervention, the patient developed an ipsilateral cluster-like headache responsive to classical interventions. Inflammation of the carotid wall near the stent was demonstrated to be associated with the headaches and was responsive to steroid treatment.The presented case demonstrates that postinterventional headache comprises more headache entities than the often reported migraine and tension-type headache with a considerable impact on the patients' quality of life. The case supports the vascular hypothesis of cluster headache pathophysiology, potentially contradicting current models and assumptions.

Extending stroke CT angiography to the full chest allows for detection of additional pulmonary opacifications in acute stroke patients.

BACKGROUND AND PURPOSE: During epidemics with an increased prevalence of pulmonary infections, extending stroke CTA examinations of acute stroke workup to the whole chest may allow for the identification of pulmonary findings that would have been missed on standard CTA examinations. MATERIALS AND METHODS: Our analysis comprised 216 patients with suspicion of stroke who received extended full-chest cerebrovascular CTA examinations from January 27th 2020 - date of the first confirmed Covid-19 case in Germany - until April 30th 2020. RESULTS: Consolidations and ground-glass opacifications were found in 73 of all 216 patients (34%). Opacifications were found in the upper chest in 51/216 patients (23%). There were lower-chest opacifications in 22 of 165 patients (13%) with unsuspicious upper-chest scans. In these 22 patients, there were consolidations in 10 cases (45%), ground-glass opacifications in 10 cases (45%), and both in 2 cases (10%). CONCLUSIONS: Our study showed that extending the scan volume of an emergency stroke CTA to the whole chest reveals a considerable number of opacifications that would have been missed on a standard CTA. Even though these findings were rarely indicative of COVID-19, a large number of opacifications warranted further investigation.

Interventional therapy of extracranial arteriovenous malformations of the head and neck-A systematic review.

OBJECTIVES: The primary aim of this study was to conduct a meta-analysis of the literature on interventional treatment for patients with extracranial AVM of the head and neck to identify a superior treatment. The secondary aim was to evaluate the methodological quality of associated articles published between 2000-2020. METHODS: The literature search was conducted on PubMed, Embase, the Cochrane Library, and scholar.google.com. Studies, meeting the acceptable reference standard underwent meta-analysis. All identified literature underwent methodological quality analysis. RESULTS: Of 1560 screened articles, 56 were included in the literature review. Appropriate diagnostic tests were reported in 98% of included articles. 13% of included articles did not specify the embolization agent. Outcome analysis varied throughout. 45% of the authors used radiographic imaging for follow-up. 77% specified the span of follow-up of their entire patient collective. Two articles met the inclusion criteria for meta-analysis. Curing rate of transarterial ethanol embolization for intraosseous AVM was 83% with a complication rate of 58%. Curing rate of ethanol combined with NBCA or Onyx in soft tissue AVM was 18% with a complication rate of 87%. CONCLUSION: Our literature review revealed an absence of treatment or reporting standards for extracranial AVM of the head and neck. The meta-analysis is comprised of two articles and methodological quality is heterogeneous. We recommend implementing consistent reporting standards to facilitate comparability of studies and to provide robust data for the development of an evidence-based treatment strategy. ADVANCES IN KNOWLEDGE: Meta-analysis showed a favorable radiological outcome for intraosseous AVM when treated with intraarterial ethanol embolization. Our analysis demonstrated that the published data on extracranial AVMs of the head and neck is lacking in consistency and quality, prompting agreement for the need of standardized reporting on AVM treatments.

Can training on ex-vivo models increase neurointerventionalists' subjective self-confidence in the operating room?

In a changing learning environment where young neurointerventionalists spend less time in the operating room, computer simulators have been established as a new training model. Our aim was the comparison of silicone models and computer simulators, and the evaluation of their influence on subjective self-confidence of operators. Pre- and postquestionnaires of 27 participants and 9 tutors were evaluated after the participation in a three-days interventional stroke course using silicone models and computer simulators. Training on computer simulators was considered as more realistic and important before patient contact than training on silicone models. Participants rated their own abilities as significantly better after participation in the course and felt significantly better prepared for patient care. Training on computer simulators can increase the subjective self-confidence of trainees. We suggest a stepwise training program, comprising both ex-vivo and the porcine in-vivo model, finished by conventional operating room teaching, to prepare neuroradiologists for optimal patient care when performing interventions.

Accuracy of Intraoperative Computed Tomography Assisted Dorsal Instrumentation in Spinal Revision Surgery.

PURPOSE: Instrumentation in spinal revision surgery is considered challenging. Altered or missing anatomical landmarks hinder the surgeons' intraoperative orientation. In recent history, the importance of navigated approaches to spinal screw placement is constantly increasing. A growing number of medical centers have introduced intraoperative CT (iCT) navigation as a new clinical standard. In this study, we compare the accuracy of dorsal iCT-navigated instrumentation in revision surgery versus primary interventions. METHODS: Between September 2017 and January 2019, we prospectively analyzed a consecutive series of dorsal instrumentation using iCT. Patients with previous operative interventions in the relevant spinal segments were included in the revision group and compared with a previously assessed group of primary interventions (nonrevision group). Each screw was assessed individually by an independent observer, making use of a modified Gertzbein and Robbins classification. RESULTS: In this period, 39 patients were treated in the revision group with a total amount of 269 implanted screws. We achieved an overall accuracy of 95.91% compared with 95.12% in the nonrevision group (46 patients, 287 screws). We found no significant difference in accuracy between the two groups or any anatomical region of the spine. CONCLUSION: In summary, iCT-navigated screw placement yields a good accuracy in spinal revision surgery, without significant difference to primary interventions.

Intraoperative Computed Tomography-Assisted Spinal Navigation in Dorsal Cervical Instrumentation: A Prospective Study on Accuracy Regarding Different Pathologies and Screw Types.

BACKGROUND: Intraoperative computed tomography (iCT) navigated dorsal instrumentation has been successfully introduced as a new clinical standard. The proximity of vital anatomic structures makes cervical spine instrumentation an especially delicate task. Therefore, navigated approaches might prove to be beneficial. In this study, the accuracy of conventional instrumentation was compared with iCT navigated dorsal cervical spine instrumentation with focus on cervical pedicle screws (CPSs) versus lateral mass screws (LMSs) and pathologies. METHODS: We analyzed a prospective consecutive series of patients undergoing cervical dorsal instrumentation with iCT and spinal navigation and retrospectively analyzed a cohort that received conventional cervical instrumentation with C-arm fluoroscopy (control group). Accuracy was assessed with a modified Gertzbein-Robbins classification. Underlying pathologies were taken into account regarding accuracy in different entities. RESULTS: Fifty-nine patients were treated using iCT (357 screws: 238 CPSs, 119 LMSs), and 98 patients underwent conventional instrumentation (632 screws: 69 CPSs, 563 LMSs). We achieved an initial accuracy of 93.28% (n = 220 screws) in the iCT group and 80.9% (n = 511 screws) in the control group (P < 0.001). Significant differences were found regarding the accuracy of CPS placement in cases of degenerative disorders (iCT vs. control; 94% vs. 63%; P < 0.001) and trauma (iCT vs. control; 88% vs. 72%; P < 0.05). iCT yielded favorable precision rates in regard to LMS placement (iCT vs. control; 94.2% vs. 82%; P < 0.05). CONCLUSIONS: Accuracy of iCT navigated instrumentation was significantly higher than conventional instrumentation. An overall tendency toward the use of CPSs with iCT navigation is evident, increasing the mechanical properties of the construct. iCT appears to be especially beneficial in elective surgery cases of degenerative spinal disorders.

Risk profile of decompressive hemicraniectomy for malignant stroke after revascularization treatment.

OBJECTIVE: Revascularization by pharmacological and/or endovascular treatment is an effective therapy for acute ischemic stroke caused by artery occlusion. In the context of malignant middle cerebral artery infarction (MMI), decompressive hemicraniectomy (DHC) can be life-saving. However, its effectiveness and safety after revascularization have not been thoroughly assessed. This retrospective study aimed to determine the risk profile of pre-surgical revascularization treatment (RT) for subsequent DHC. METHODS: A total of 152 consecutive patients treated by DHC after MMI were identified between 2012 and 2015. After elimination of cases with previous stroke and cases pre-treated with antiplatelets or anticoagulants (increased postoperative bleeding), twenty-four out of fifty patients (n = 24/50, 48%) received pre-surgical revascularization treatment by intravenous thrombolysis (TL), mechanical thrombectomy (MT) or a combination of both. Demographic data was compared alongside perioperative, postoperative complications (intra-/extracerebral hemorrhage, revision surgery due to hemorrhage or infection, and overall mortality) and economic parameters. RESULTS: Comparing patients with and without prior RT, there was no statistically significant difference in duration of surgery (RT: 83 [57-116] min vs. no-RT: 96 [69-119] min, p = 0.308), intraoperative blood loss (RT: 300 [225-375] ml vs. no-RT: 300 [250-400] ml, p = 0.763), intraoperative transfusion requirement (RT: 12.5% vs. no-RT: 26.9%, p = 0.294), or need for volume substitution (RT: 1300 [1200-1400] ml vs. no-RT: 1200 [1100-1400] ml, p = 0.359). The rate of postoperative complications was also comparable in both groups, including intra-/extracerebral hemorrhage, revision due to hemorrhage or infections, and mortality (p = 0.814, p = 0.520, p = 0.697, and p = 0.769). Health economic parameters were not affected (ventilation time: RT: 309 [12-527] hrs. vs. no-RT: 444 [171-605] hrs., p = 0.120, length of stay: RT: 23 [13-32] days vs. no-RT: 28 [19-41], p = 0.156, and stay costs: RT: 27768 [13044-60,248] € vs. no-RT: 35422 [21225-49,585] €, p = 0.312). CONCLUSION: DHC for patients with MMI who previously received revascularization therapy appears to be safe and not associated with a higher complication rate or increased health economic burden.

Risk of postprocedural intracerebral hemorrhage in patients with ruptured cerebral aneurysms after treatment with antiplatelet agents.

OBJECTIVE: Endovascular treatment of ruptured cerebral aneurysms frequently requires antiplatelet medication to prevent thromboembolism. This might raise concern regarding the risk of postprocedural hemorrhage (pH), e.g. from placement of intracranial probes. We explored the risk of PH associated with standard antiplatelet therapy (sAP: acetylsalicylic acid, and/or clopidogrel) in the context of aneurysmal subarachnoid hemorrhage (aSAH). METHODS: We retrospectively reviewed a total of 146 consecutive cases with cerebral aneurysms treated between 1/2011-12/2015, and distinguished between minor (0.5 cm3) - 4 cm3) or major (> 4 cm3) PH occurring within four weeks after intervention. A separate analysis included hemorrhages related to placement of intracranial probes and drainages in the subgroup of 99 cases with such surgical interventions (pPH). Clinical outcome was assessed via Glasgow Outcome Scale (GOS) twelve months after aSAH. RESULTS: A total of 49 cases (33.6%) in the overall sample sustained PH, there were 19 cases of pPH. Multifactorial analyses yielded sAP as an independent predictor for minor, but not major PH (p < 0.001 vs. p = 0.829), with comparable results for pPH (p = 0.001 vs. p = 0.184). sAP did not influence the clinical outcome in either group. CONCLUSIONS: sAP was associated with a higher rate of minor PH and, more specifically, of minor pPH. However, it was neither accompanied by the occurrence of major hemorrhages nor by unfavorable clinical outcome. Future prospective studies should confirm these observations and hemorrhage risks associated with extended anticoagulation regimes after complex interventions and intra-arterial vasospasm therapy should be explored in order to facilitate interdisciplinary decision-making in aSAH.

Can silicone models replace animal models in hands-on training for endovascular stroke therapy?

PURPOSE: Since thrombectomy has become a standard treatment technique for stroke, there is great demand for well-trained interventionalists. We offer practical courses on both silicone models and porcine models, and conducted a survey to evaluate whether ex vivo training models could replace in vivo models in the future. METHODS: In total, 110 neurointerventionalists participating in 30 training courses were included in our survey using a semi-structured questionnaire. RESULTS: The level of experience in thrombectomy maneuvers was almost balanced in our sample (52% experienced and 48% less-experienced participants). Silicone models were regarded as useful training tools regardless of the participants' experience (p = 1.000): 94% of less-experienced and 92% of experienced participants considered a silicone model to be a useful introduction for training with animal models. Of the participants, 95% indicated that training on animal models was helpful and necessary, even if they already had experience in performing interventions in humans (p = 1.000). After joining this course, 97% of all participants felt well prepared to perform thrombectomies in humans. CONCLUSION: Even experienced participants benefit from silicone models. Silicone models are a good preparation for animal models but cannot replace them. Categorizing participants depending on their experience and their individual needs before practical training may allow for more efficient endovascular training.

Combined Surgical and Endovascular Carotid Access for Endovascular Thrombectomy in Acute Ischemic Stroke.

OBJECTIVE: Conventional carotid catheterization is impossible in 2%-5% of acute stroke cases. Surgical carotid cutdown may be a necessary bailout strategy to allow for carotid access. We assessed the effectiveness and safety of surgical carotid cutdown for vascular access in interventional acute stroke treatment. METHODS: We compare imaging and clinical data of 15 consecutive patients, in whom we performed a carotid cutdown for acute stroke treatment with 10 consecutive patients, in whom treatment was discontinued because transfemoral access to the occlusion site was not possible. RESULTS: Baseline characteristics of both groups were comparable (P ≥ 0.065). Cutdown patients had significantly smaller infarctions (P = 0.031), significantly more often favorable clinical outcome (38% vs. 0% modified Rankin score 0-2, P = 0.046), and a lower mortality (31% vs. 60%, P = 0.222) at 3 months. Other than a small hematoma at the operation site, there were no procedure-related complications. CONCLUSIONS: Carotid cutdown is an effective bailout strategy for acute stroke patients, in whom conventional catheterization is not possible.

The SAVE Technique : Large-Scale Experience for Treatment of Intracranial Large Vessel Occlusions.

BACKGROUND: The stent retriever assisted vacuum-locked extraction (SAVE) technique was introduced as an effective thrombectomy method in stroke patients suffering from intracranial large vessel occlusion (LVO). This article presents our multicenter, large-scale experience with SAVE. METHODS: The study involved a retrospective core team analysis of 200 patients undergoing mechanical thrombectomy using the SAVE technique due to intracranial LVO at 4 German centers. Primary endpoints were first-pass and overall complete/near complete reperfusion, defined as a modified thrombolysis in cerebral infarction (mTICI) score of 2c and 3. Secondary endpoints were the number of passes, time from groin puncture to reperfusion, embolization to new territories (ENT), postinterventional symptomatic intracranial hemorrhage (sICH), and favorable outcome at discharge, defined as a modified Rankin Scale (mRS) score ≤ 2. RESULTS: The median age was 78 years (interquartile range IQR 68-85). Median National Institutes of Health stroke scale (NIHSS) at admission was 16 (IQR 12-20). Occlusions sites were: internal carotid artery (ICA-T) in 39/200 (19.5%), M1 in 126/200 (63%), M2 in 30/200 (15%), and others in 5/200 (2.5%) cases. The primary endpoints were documented in 114/200 (57% first pass mTICI 2c or 3) and 154/200 (77% overall mTICI 2c or 3) patients, respectively. The overall median time from groin puncture to reperfusion was 34 min (IQR 25-52) with a median of 1 (IQR 1-2) attempts. An ENT was observed in 3 patients (1.5%) and the rate of sICH was 2.6%. The rate of successful reperfusion (mTICI ≥ 2b) on final angiograms was 95%. At discharge, 73/200 (36.5%) patients revealed a favorable outcome. CONCLUSION: Mechanical thrombectomy using the SAVE technique seems to be effective, fast and safe. First-line use of SAVE leads to high rates of complete and near complete reperfusion.