First-Pass Recanalization with EmboTrap II in Acute Ischemic Stroke (FREE-AIS): A Multicenter Prospective Study

Objective@#We aimed to evaluate the efficacy of EmboTrap II in terms of first-pass recanalization and to determine whether it could yield favorable outcomes. @*Materials and Methods@#In this multicenter, prospective study, we consecutively enrolled patients who underwent mechanical thrombectomy using EmboTrap II as a front-line device. The primary outcome was the first pass effect (FPE) rate defined by modified Thrombolysis In Cerebral Infarction (mTICI) grade 2c or 3 by the first pass of EmboTrap II. In addition, modified FPE (mFPE; mTICI grade 2b–3 by the first pass of EmboTrap II), successful recanalization (final mTICI grade 2b–3), and clinical outcomes were assessed. We also analyzed the effect of FPE on a modified Rankin Scale (mRS) score of 0–2 at 3 months. @*Results@#Two hundred-ten patients (mean age ± standard deviation, 73.3 ± 11.4 years; male, 55.7%) were included. Ninetynine patients (47.1%) had FPE, and mFPE was achieved in 150 (71.4%) patients. Successful recanalization was achieved in 191 (91.0%) patients. Among them, 164 (85.9%) patients underwent successful recanalization by exclusively using EmboTrap II. The time from groin puncture to FPE was 25.0 minutes (interquartile range, 17.0–35.0 minutes). Procedure-related complications were observed in seven (3.3%) patients. Symptomatic intracranial hemorrhage developed in 14 (6.7%) patients. One hundred twenty-three (58.9% of 209 completely followed) patients had an mRS score of 0–2. Sixteen (7.7% of 209) patients died during the follow-up period. Patients who had successful recanalization with FPE were four times more likely to have an mRS score of 0–2 than those who had successful recanalization without FPE (adjusted odds ratio, 4.13;95% confidence interval, 1.59–10.8; p = 0.004). @*Conclusion@#Mechanical thrombectomy using the front-line EmboTrap II is effective and safe. In particular, FPE rates were high. Achieving FPE was important for an mRS score of 0–2, even in patients with successful recanalization.

Endovascular Treatment of Acute Ischemic Stroke

Acute ischemic stroke is one of the leading causes of disability and death around the world, especially in developed countries. Since the introduction of the 2nd generation devices, endovascular treatment of acute ischemic stroke has rapidly developed and is now considered to be a standard treatment. Here, we summarize the results of recent randomized clinical trials that have compared endovascular thrombectomy with conventional treatment for acute stroke and review the indications, current devices, and endovascular thrombectomy methods used.

Predictors of Good Outcomes in Patients with FailedEndovascular Thrombectomy

Objective@#Endovascular thrombectomy (EVT) fails in approximately 20% of anterior circulation large vessel occlusion (ACLVO).Nonetheless, the factors that affect clinical outcomes of non-recanalized AC-LVO despite EVT are less studied. Thepurpose of this study was to identify the factors affecting clinical outcomes in non-recanalized AC-LVO patients despite EVT. @*Materials and Methods@#This was a retrospective analysis of clinical and imaging data from 136 consecutive patients whodemonstrated recanalization failure (modified thrombolysis in cerebral ischemia [mTICI], 0–2a) despite EVT for AC-LVO. Datawere collected in prospectively maintained registries at 16 stroke centers. Collateral status was categorized into good or poorbased on the CT angiogram, and the mTICI was categorized as 0–1 or 2a on the final angiogram. Patients with good (modifiedRankin Scale [mRS], 0–2) and poor outcomes (mRS, 3–6) were compared in multivariate analysis to evaluate the factorsassociated with a good outcome. @*Results@#Thirty-five patients (25.7%) had good outcomes. The good outcome group was younger (odds ratio [OR], 0.962;95% confidence interval [CI], 0.932–0.992; p = 0.015), had a lower incidence of hypertension (OR, 0.380; 95% CI, 0.173–0.839; p = 0.017) and distal internal carotid artery involvement (OR, 0.149; 95% CI, 0.043–0.520; p = 0.003), lower initialNational Institute of Health Stroke Scale (NIHSS) (OR, 0.789; 95% CI, 0.713–0.873; p < 0.001) and good collateral status(OR, 13.818; 95% CI, 3.971–48.090; p < 0.001). In multivariate analysis, the initial NIHSS (OR, 0.760; 95% CI, 0.638–0.905; p = 0.002), good collateral status (OR, 14.130; 95% CI, 2.264–88.212; p = 0.005) and mTICI 2a recanalization (OR,5.636; 95% CI, 1.216–26.119; p = 0.027) remained as independent factors with good outcome in non-recanalized patients. @*Conclusion@#Baseline NIHSS score, good collateral status, and mTICI 2a recanalization remained independently associatedwith clinical outcome in non-recanalized patients. mTICI 2a recanalization would benefit patients with good collaterals innon-recanalized AC-LVO patients despite EVT.

Coil-Protected Technique for Liquid Embolization in Neurovascular Malformations

OBJECTIVE: To evaluate the safety and efficacy of the coil-protected technique for liquid embolization in neurovascular malformations. MATERIALS AND METHODS: Twenty-two patients who underwent coil-protected liquid embolization for symptomatic cranial (n = 13) and spinal (n = 9) arteriovenous fistula (AVF) or arteriovenous malformations (AVMs) were identified. A total of 36 target feeder vessels were embolized with N-butyl cyanoacrylate and/or Onyx (Medtronic). This technique was used to promote delivery of a sufficient amount of liquid embolic agent into the target shunt or nidus in cases where tortuous feeding arteries preclude a microcatheter wedging techniqu and/or to prevent reflux of the liquid embolic agent in cases with a short safety margin. The procedure was considered technically successful if the target lesion was sufficiently filled with liquid embolic agent without unintentional reflux. Angiographic and clinical outcomes were retrospectively evaluated. RESULTS: Technical success was achieved for all 36 target feeders. Post-embolization angiographies revealed complete occlusion in 16 patients and near-complete and partial occlusion in three patients each. There were no treatment-related complications. Of the six patients who showed near-complete or partial occlusion, five received additional treatments: two received stereotactic radiosurgery for cerebral AVM, two underwent surgical removal of cerebral AVM, and one underwent additional embolization by direct puncture for a mandibular AVM. Finally, all patients showed complete (n = 19) or near-complete (n = 3) occlusion of the target AVF or AVM on follow-up angiographies. The presenting neurological symptoms improved completely in 15 patients (68.2%) and partially in seven patients (31.8%). CONCLUSION: The coil-protected technique is a safe and effective method for liquid embolization, especially in patients with various neurovascular shunts or malformations who could not be successfully treated with conventional techniques.

Length and Volume of Morphologically Normal Kidneys in Korean Children: Ultrasound Measurement and Estimation Using Body Size

OBJECTIVE: To evaluate the relationship between anthropometric measurements and renal length and volume measured with ultrasound in Korean children who have morphologically normal kidneys, and to create simple equations to estimate the renal sizes using the anthropometric measurements. MATERIALS AND METHODS: We examined 794 Korean children under 18 years of age including a total of 394 boys and 400 girls without renal problems. The maximum renal length (L) (cm), orthogonal anterior-posterior diameter (D) (cm) and width (W) (cm) of each kidney were measured on ultrasound. Kidney volume was calculated as 0.523 x L x D x W (cm3). Anthropometric indices including height (cm), weight (kg) and body mass index (m2/kg) were collected through a medical record review. We used linear regression analysis to create simple equations to estimate the renal length and the volume with those anthropometric indices that were mostly correlated with the US-measured renal sizes. RESULTS: Renal length showed the strongest significant correlation with patient height (R2, 0.874 and 0.875 for the right and left kidneys, respectively, p < 0.001). Renal volume showed the strongest significant correlation with patient weight (R2, 0.842 and 0.854 for the right and left kidneys, respectively, p < 0.001). The following equations were developed to describe these relationships with an estimated 95% range of renal length and volume (R2, 0.826-0.884, p < 0.001): renal length = 2.383 + 0.045 x Height (+/- 1.135) and = 2.374 + 0.047 x Height (+/- 1.173) for the right and left kidneys, respectively; and renal volume = 7.941 + 1.246 x Weight (+/- 15.920) and = 7.303 + 1.532 x Weight (+/- 18.704) for the right and left kidneys, respectively. CONCLUSION: Scatter plots between height and renal length and between weight and renal volume have been established from Korean children and simple equations between them have been developed for use in clinical practice.

Langerhans Cell Histiocytosis with Pancreatic Involvement: Imaging Findings Including Diffusion-Weighted Imaging

Langerhans cell histiocytosis (LCH) can affect many different organs. However, LCH with pancreatic involvement is very rare with a few reports about imaging findings. We present a case of multisystemic LCH with pancreatic involvement in a five-week-old infant. Pancreas lesion showed hypoechoic on ultrasonography, low density with poor enhancement on CT, and restricted diffusion on diffusion-weighted imaging. Although LCH with pancreatic involvement is rare, LCH should be considered in the differential diagnosis of pancreatic mass in children.