An Intermodal Correlation Study among Imaging, Histology, Procedural and Clinical Parameters in Cerebral Thrombi Retrieved from Anterior Circulation Ischemic Stroke Patients.

The precise characterization of cerebral thrombi prior to an interventional procedure can ease the procedure and increase its success. This study investigates how well cerebral thrombi can be characterized by computed tomography (CT), magnetic resonance (MR) and histology, and how parameters obtained by these methods correlate with each other as well as with the interventional procedure and clinical parameters. Cerebral thrombi of 25 patients diagnosed by CT with acute ischemic stroke were acquired by mechanical thrombectomy and, subsequently, scanned by a high spatial-resolution 3D MRI including T1-weighted imaging, apparent diffusion coefficient (ADC), T2 mapping and then finally analyzed by histology. Parameter pairs with Pearson correlation coefficient more than 0.5 were further considered by explaining a possible cause for the correlation and its impact on the difficulty of the interventional procedure and the treatment outcome. Significant correlations were found between the variability of ADC and the duration of the mechanical recanalization, the deviation in average Hounsfield units (HU) and the number of passes with the thrombectomy device, length of the thrombus, its RBC content and many others. This study also demonstrates the clinical potentials of high spatial resolution multiparametric MRI in characterization of thrombi and its use for interventional procedure planning.

Study of correlations between CT properties of retrieved cerebral thrombi with treatment outcome of stroke patients.

BACKGROUND: All the patients with suspected stroke are directed to whole-brain CT scan. The purpose of this scan is to look for early features of ischemia and to rule out alternative diagnoses than stroke. In case of ischemic stroke, CT diagnostics (including CT angiography) is used mainly to locate the occlusion and its size, while the Hounsfield Units (HU) values of the thrombus causing the stroke are usually overlooked on CT scan or considered not important. The aim of this study was to demonstrate that the HU value is relevant and can help in better treatment planning. PATIENTS AND METHODS: There were 25 patients included in the study, diagnosed with ischemic stroke in the middle cerebral artery (MCA) territory. In all patients, systemic thrombolysis was not successful and the mechanical recanalization was needed. The retrieved thrombi were also analyzed histologically for the determination of red blood cells (RBC) proportion. CT of the proximal MCA (M1) segment was analyzed for average HU value and its variability both in the occluded section and the symmetrical normal site. These CT parameters were then statistically studied for the possible correlations with different clinical, histological and procedure parameters using the Linear Regression and the Pearson correlation coefficient. RESULTS: Relevant positive correlations were found between average HU value of thrombus and outcome modified Rankin Scale (mRS), initial mRS, number of passes with thrombectomy device as well as RBC proportion. CONCLUSIONS: Results of the present study suggest that measured HU values in CT images of the cerebral thrombi may help in the assessment of thrombus compaction and therefore better treatment planning.

Mechanical recanalization for acute bilateral cerebral artery occlusion - literature overview with a case.

Background Acute bilateral internal carotid artery (ICA) and/or middle cerebral artery (MCA) occlusion is extremely rare and associated with poor clinical outcomes. There are only a few reports in the literature about mechanical thrombectomy being performed for acute bilateral occlusions. The treatment strategies and prognoses (clinical outcomes) are therefore unclear. Methods A systematic review of the literature was performed through several electronic databases with the following search terms: acute bilateral stroke, mechanical recanalization and thrombectomy. Results In the literature, we identified five reports of six patients with bilateral ICA and/or MCA occlusion treated with mechanical recanalization. Additionally, we report our experience with a subsequent contralateral large brain artery occlusion during intravenous thrombolytic therapy, where the outcome after mechanical thrombectomy was not dependent on the time from stroke onset but rather on the capacity of collateral circulation exclusively. Conclusions Acute bilateral cerebral (ICA and/or MCA) occlusion leads to sudden severe neurological deficits (comas) with unpredicted prognoses, even when mechanical recanalization is available. As the collateral capacity seems to be more important than the absolute time to flow restoration in determining the outcomes, simultaneous thrombectomy by itself probably does not lead to improved functional outcomes.

Retrieved cerebral thrombi studied by T2 and ADC mapping: preliminary results.

Background Recent advances in MRI technology makes it increasingly more competitive to CT also in the field of interventions. Multi-parametric MRI offers a significant amount of data relevant for characterization of human cerebral thrombi. Patients and methods Cerebral thrombi of 17 patients diagnosed with acute stroke were acquired by mechanical thrombectomy. The thrombi were subsequently scanned using a high spatial-resolution 3D T1-weighted MRI to obtain morphological characteristics of the thrombi and also by apparent diffusion coefficient (ADC) and transversal nuclear magnetic resonance (NMR) relaxation time (T2) mapping. The MRI results were analysed for possible correlations between thrombectomy procedure parameters (recanalization time and number of passes) and MR-measurable parameters (sample-mean ADC and T2, within-sample coefficient of variation of ADC and T2, and thrombus length). Results Both MRI mapping techniques enabled a good discrimination among thrombi regions of different water mobility and compaction. Within-sample coefficient of variation of ADC was found most sensitive for discrimination between the thrombi where thrombectomy procedure was performed in a single pass and those where is was performed in two or more passes (p = 0.03). Interestingly, negative correlation was found between the recanalization time and thrombus length (ρ = -0.22). Conclusions Preliminary results of presented study shows that pretreatment MRI assessment of thrombi in stroke patients could potentially ease stroke treatment planning. In this study it is shown that within-sample coefficient of variation of ADC could serve for prediction of possible complications during thrombectomy procedures.

Endovascular therapy for acute stroke is a safe and efficient evolving method: a single-center retrospective analysis.

PURPOSE: To determine the clinical outcome in patients undergoing endovascular therapy for acute stroke. MATERIALS AND METHODS: During the period 2009-2012, 134 patients with acute stroke and normal computed tomography (CT) findings were treated with endovascular therapy at a single center. Based on CT perfusion and CT angiography findings, all patients had large vessel occlusions. Intravenous thrombolysis was used in eligible patients. The recanalization rate, time to recanalization, periprocedural complications, and clinical outcome at discharge from the hospital (National Institutes of Health score, modified Rankin Scale [mRS]) were analyzed. RESULTS: The recanalization rate during the study interval increased from 70% (2008-2009) to 94% (2011-2012) (P ≤ .01). The procedure time was reduced from 124 minutes (2009) to 43 minutes (2012) (P ≤ .01), and the periprocedural complication rate decreased from 21% (2009) to 2% (2012) (P ≤ .01). Patients in 2009-2010 had a 2.21 times greater probability for an mRS score ≥ 2 after the procedure compared with patients in 2011-2012 (95% confidence interval, 1.0-5.0). If the procedure lasted 15 minutes longer, the prospect for an mRS score ≥2 after the procedure was 1.30 times greater (P = .02). CONCLUSIONS: High recanalization rates, low procedural complications, and improved clinical outcomes were achieved using endovascular therapy in selected patients with acute stroke during a 4-year period. Endovascular therapy is an evolving safe and effective treatment for intracranial large vessel occlusion.

Magnetic resonance spectroscopy (MRS) of vertebral column - an additional tool for evaluation of aggressiveness of vertebral haemangioma like lesion.

BACKGROUND: Most vertebral haemangioma are asymptomatic and discovered incidentally. Sometimes the symptomatic lesions present with radiological signs of aggressiveness and their appearance resemble other aggressive lesions (e.g. solitary plasmacytoma). CASE REPORT: We present a patient with large symptomatic aggressive haemangioma like lesion in 12(th) thoracic vertebra in which a magnetic resonance spectroscopy (MRS) was used to analyse fat content within the lesion. The lesion in affected vertebrae showed low fat content with 33% of fat fraction (%FF). The fat content in non-affected (1(st) lumbar) vertebra was as expected for patient's age (68%). Based on MRS data, the lesion was characterized as an aggressive haemangioma. The diagnosis was confirmed with biopsy, performed during the treatment - percutaneous vertebroplasty. CONCLUSIONS: The presented case shows that MRS can be used as an additional tool for evaluation of aggressiveness of vertebral haemangioma like lesions.

Minimally invasive (percutaneous) treatment of metastatic spinal and extraspinal disease--a review.

Metastatic tumors are the most common malignancy of bone. Many patients with spinal metastases present with pain and pathologic fractures. The advent of interventional radiology resulted in alternative and less invasive treatment of these patients. This article presents minimally invasive (percutaneous) procedures that are currently in use, i.e. vertebroplasty, kyphoplasty, osteoplasty, radiofrequency ablation, cryoablation, and transarterial embolization. Indications, contraindications, results and complications are also discussed. According to our current knowledge of the results reported in the literature, minimally invasive techniques are successful methods for the treatment of metastatic spinal and extraspinal disease and can be used as alternative treatment to standard surgical or non-surgical procedures.

Minimally invasive CT guided treatment of intraspinal synovial cyst.

BACKGROUND: Intraspinal synovial cysts of vertebral facet joints are uncommon cause of radicular pain as well as neurological deficits. They can be managed both conservatively and surgically. CASE REPORT: A 77-year old polymorbid patient presented with bilateral low back pain which worsened during the course of time and did not respond to the conservative treatment. A diagnosis of intraspinal synovial cyst was made using the magnetic resonance imaging (MRI). Percutaneous computed tomography (CT) guided injection with installation of local anesthetic together with corticosteroid and rupture of the cyst was successfully used. A month after the procedure his pain improved, the usage of analgesics diminished and his over-all quality of life improved. CONCLUSIONS: Percutaneous CT guided lumbar synovial cyst treatment is safe and reliable alternative to the surgical treatment in polymorbid patients with radiculopathy who are not able to tolerate general anesthesia and operation.

Iodine based radiopacity of experimental blood clots for testing of mechanical thrombectomy devices.

BACKGROUND: Barium sulfate powder used for radiopacity of experimental blood clots (EBCs) for testing mechanical thrombectomy devices (MTD) has negative effects on EBCs mechanical properties. In vitro and in vivo exploration was performed to determine if the iodine based contrast medium will have less negative effects on the EBCs than barium. MATERIALS AND METHODS: Fresh blood from 2 swine was used to create fibrinogen enhanced and thrombin initiated EBC in tubes. Iodine radiopacity was achieved by mixing the blood with 65% Iohexol or by soaking the EBCs for 2 or 24 hours in Iohexol. The EBCs opacified with barium served as controls. In vitro study: The EBCs were subjected to four tests, manual elongation, catheter injection, radiopacity and contrast wash out tests. In vivo study: The common carotid arteries of 2 swine were embolized by either barium EBC or EBC soaked for 24 hours in Iohexol. The duration of radiopacity of the different EBCs was compared. RESULTS: The EBCs opacified with Iohexol initially had higher radiopacity than the barium opacified EBCs. However, their opacity rapidly decreased with saline soaking and, particularly, after they were embolized in live animals. The mechanical properties of Iohexol opacified EBCs were inferior to barium opacified EBCs. The Iohexol mixed EBCs were less firm and elastic and half of them fragmented during catheter injection. The Iohexol soaked EBCs exhibited decreased tensile strength and elasticity compared to the barium EBCs. CONCLUSIONS: Compared to barium, iodine based contrast medium does not offer any advantage for opacifying EBCs.

Mechanical revascularization for acute ischemic stroke: a single-center, retrospective analysis.

BACKGROUND: Endovascular mechanical revascularization (thrombectomy) is an increasingly used method for intracranial large vessel recanalization in acute stroke. The purpose of the study was to analyze the recanalization rate, clinical outcome, and complication rate in our stroke patients treated with mechanical revascularization. METHODS: A total of 57 patients with large vessel stroke (within 3 h for anterior and 12 h for posterior circulation) were treated with mechanical revascularization at a single center during 24 months. The primary goal of endovascular treatment using different mechanical devices was recanalization of the occluded vessel. Recanalization rate (reported as thrombolysis in cerebral infarction [TICI] score), clinical outcome (reported as National Institutes of Health Stroke Scale [NIHSS] score and modified Rankin scale [mRS] score), as well as periprocedural complications were analyzed. RESULTS: The mean age of the patients was 63.1 ± 12.9 years, with baseline median NIHSS score of 14 (interquartile range, 9.5-19). Successful recanalization (TICI 2b or 3) was achieved in 41 (72 %) patients. Twenty patients (35 %) presented with favorable outcome (mRS ≤2) 30 days after stroke. Overall, significant neurological improvement (≥4 NIHSS point reduction) occurred in 36 (63 %) patients. A clinically significant procedure-related adverse events (vessel disruption, peri/postprocedural intracranial bleeding) defined with decline in NIHSS of ≥4 or death occurred in three (5 %) patients. CONCLUSIONS: The study showed a high recanalization rate with improved clinical outcome and a low rate of periprocedural complications in our stroke patients treated with mechanical revascularization. Therefore, we could conclude that endovascular revascularization (primary or in combination with a bridging thrombolysis) was an effective and safe procedure for intracranial large vessel recanalization in acute stroke.

Double BioDisk: a new bioprosthetic device for transcatheter closure of atrial septal defects - a feasibility study in adult sheep.

BACKGROUND: To evaluate the long-term effectiveness and safety of a new Double BioDisk (DBD) device for closure of atrial septal defect (ASD). MATERIALS AND METHODS.: ASD was created with transeptal needle (TS) followed by balloon dilatation in 12 sheep weighing 40.1 to 64 kg (mean 55.2 ± 7.1). The ASD diameters were measured after creation and two weeks later before DBD implantation. The DBDs consists of two nitinol rings 18 to 28 mm in diameter connected with small cannulas and covered with a porcine small intestinal submucosa (SIS). They were implanted via a 10 Fr sheath. DBD effectiveness was evaluated by angiocardiography and by intra-cardiac echogram (ICE) with Doppler studies. Two animals were acute, two were followed for 6 weeks, three for 3 months, three for 6 months and two for 12 months. RESULTS: TS punctures were successful in 10 sheep. In two sheep ASD was created by existing PFO dilation. The ASD size ranged from 13-15 mm (mean 14.1± 0.73 mm) after initial balloon dilation and from 9-13 mm (mean 10.06 ± 1.37 mm) after two weeks. In all animals none of the successfully implanted DBDs spontaneously embolized on release or on follow up. ICE demonstrated no shunting around the DBDs during follows ups. Macroscopic and histologic evaluation of the 6, 12, 24 and 52 weeks animals showed that DBDs were well incorporated in the atrial septum with complete shunt closure. The SIS showed progressive remodeling with the host cells, including endothelization of the DBD devices. CONCLUSIONS: ASD closure with the Double BioDisk is safe and effective in adult sheep.

Stroke patients who regain urinary continence in the first week after acute first-ever stroke have better prognosis than patients with persistent lower urinary tract dysfunction.

AIMS: Urinary incontinence (UI) is a predictor of greater mortality and poor functional recovery; however published studies failed to evaluate lower urinary tract (LUT) function immediately after stroke. The aim of our study was to evaluate the course of LUT function in the first week after stroke, and its impact on prognosis. METHODS: We included 100 consecutively admitted patients suffering first-ever stroke and evaluated them within 72 hours after stroke, after 7 days, 6 months, and 12 months. For LUT function assessment we used ultrasound measurement. The patients were divided into three groups: (i) patients who remained continent after stroke, (ii) patients who had LUT dysfunction in the acute phase but regained continence in the first week, and (iii) patients who did not regain normal LUT control in the first week. We assessed the influence of variables on death using the multiple logistic regression model. RESULTS: Immediately after stroke 58 patients had LUT dysfunction. The odds of dying in group with LUT dysfunction were significantly larger than odds in group without LUT dysfunction. Odds for death for patients who regained LUT function in 1 week after stroke were comparable to patients without LUT dysfunction. CONCLUSIONS: We confirmed that post-stroke UI is a predictor of greater mortality at 1 week, 6 months and 12 months after stroke. However, patients who regain normal bladder control in the first week have a comparable prognosis as the patients who do not have micturition disturbances following stroke.

New coaxial transseptal needle for creation of atrial septal defects in adult sheep.

OBJECTIVES: To introduce a new transseptal (TS) needle assembled in our laboratory--the coaxial TS (CTS) needle--and describe our experience with it in creating experimental atrial septal defects (ASD) in adult sheep. BACKGROUND: With commercially available TS needles, we were not able to consistently perform TS puncture at the fossa ovalis in adult sheep. MATERIAL AND METHODS: Ten adult sheep with a mean weight of 63.5 kg were used. The CTS needle consists of four components: a 9F Teflon catheter, a 14-gauge blunt curved-tip metal cannula, a 4F tapered catheter, and a 20-gauge open needle. A transjugular 5F pigtail catheter was used to display the septal anatomy by angiocardiography and was left in place to mark the level of the fossa ovalis. The septum was then probed by a transfemoral 5F curved-tip end-hole catheter. The CTS needle was aligned with the tip of the transjugular catheter, and the TS puncture was performed under fluoroscopic guidance. After documenting a left atrial position, a balloon angioplasty catheter was used for creation of the ASD. RESULTS: A small patent foramen ovale was discovered by septal probing in one sheep. All sheep underwent successful TS punctures without complications. The ASD size ranged from 13 to 15 mm. In eight sheep, the ASD was in fossa ovalis. In the first two sheep where the needle was not well aligned with the marking catheter, the ASD was in the septum secundum. No damage to the atrial or other heart structures was found at necropsy. CONCLUSION: The CTS needle is a suitable needle for TS puncture and ASD creation in adult sheep. Proper alignment of the CTS needle with a catheter marking the fossa ovalis is essential for successful puncture.

Percutaneous transcatheter arterial embolization in haemodynamically stable patients with blunt splenic injury.

BACKGROUND: The nonoperative management of the blunt splenic injury in haemodynamically stable patients has become an accepted treatment in recent years. We present a case of the blunt splenic injury successfully treated by supraselective embolization with microspheres. CASE REPORT: A young hockey player was brought to the Emergency Department with the history of blunt abdominal trauma 2 h earlier. A Grade III splenic injury with haemoperitoneum was diagnosed on sonographic evaluation and the patient was treated with the selective distal splenic artery embolization with microspheres. Postprocedural ultrasound and computed tomography follow-up a year later revealed only a small area of parenchymal irregularity. CONCLUSIONS: The percutaneous splenic arterial embolization has a major role in the management of traumatic splenic injuries. Embolization is particularly beneficial in injuries of grade III or higher.

Hemostatic efficacy of chitosan-based bandage for closure of percutaneous arterial access sites: An experimental study in heparinized sheep model.

BACKGROUND: Most of the presently used percutaneous arterial closure devices (PACD) for hemostasis after interventional vascular procedures are effective, but carry risk of complications by deposition of a foreign body. A new promising externally applied PACD - chitosan-based HemCon Bandage (HCB) was explored in sheep. The HCB hemostatic efficacy and complications occurring with its use were compared to those with the standard manual compression (SMC). MATERIAL AND METHODS: Both superficial femoral arteries (SFA) of 9 heparinized sheep were catheterized with an 8F sheath for 5 minutes. After the sheath withdrawal, hemostasis with the HCB was compared with hemostasis achieved with SMC in the contralateral SFA. Iliac angiograms performed by carotid artery approach determined the hemostasis time. RESULTS: The HCB use shortened time to hemostasis with a mean time of 6.9 ± 3.9 minutes versus 10.8 ± 2.8 minutes for the SMC (P-value 0.019). Seven SFAs in the HCB group and only 1 SFA in the SMC group exhibited hemostasis in 5 minutes. All nine SFAs using the HCB showed femoral artery patency and demonstrated less hematoma (2/9) than in the SMC group (8/9). No complications developed in the HCB group, one SFA occlusion was seen in the SMC group. CONCLUSIONS: The externally applied HCB in heparinized sheep was safe and effective. It significantly shortened time to hemostasis at the SFA access sites following 8F sheath removal. Proper application of the HCB was necessary to shorten hemostasis and prevent hematoma formation. The HCB should be tested in a clinically controlled study to evaluate its efficacy in humans.

Infrahepatic caudal/inferior vena cava interruption with azygos/hemiazygos continuation. Vascular anomaly in swine.

BACKGROUND: Swine are commonly used as a model to study congenital cardiovascular defects that occur in humans and these models have been both spontaneous and experimentally induced. Ventricular septal defect, patent ductus arteriosus, and atrial septal defect (ASD) are examples of experimentally induced models. Absence of caudal/inferior vena cava (CVC/IVC) with azygos/hemiazygos continuation is an uncommon vascular anomaly. CASE REPORT: The vascular anomaly presented in this case report was an incidental finding on a pig that was evaluated for experimental percutaneous atrial septal defect creation and its closure using a percutaneous femoral vein approach. Absence of CVC/IVC was confirmed by venography and necropsy. CONCLUSIONS: To the best of the investigators knowledge, this is the first report of absence of CVC/IVC with azygos/hemiazygos continuation in the swine.