Multiple stent delivery system Multi-LOC, a new technology for spot-stenting of the femoropopliteal artery - proof of concept study in a preclinical large animal model.

BACKGROUND: A new stent system was studied in a porcine model to evaluate its feasibility for spot-stenting of the femoropopliteal artery. MATERIALS AND METHODS: In a preliminary study in a single pig, handling and mechanical features of the novel multiple stent delivery system were tested. The Multi-LOC system demonstrated great feasibility regarding its pushability, trackability, and crossability. Excellent visibility of the individual stents allowed exact anatomically controlled implantation. In our main study, four to five short Multi-LOC stents (13 mm long) were implanted into the femoropopliteal arteries of six domestic pigs and long (60 to 100 mm) self-expandable nitinol stents were implanted into the same target vessel contralaterally to allow for intraindividual comparison. After four weeks survival under dual antiplatelet treatment, control angiography was performed. The animals were euthanized, stented vessels were explanted, and histologic sections were examined for the presence of neointimal formation. RESULTS: Multi-LOC stents demonstrated no occlusion of the femoropopliteal axis (0 vs. 1 occlusion distal to a control stent), no stent fractures (0 out of 26 vs. 2 out of 6 control stents), and lower percentage diameter stenosis (0.564 ± 0.056 vs. 0.712 ± 0.089; p = 0.008) and length of stenosis (19.715 ± 5.225 vs. 39.397 ± 11.182; p = 0.007) compared to a standard control stent, which was similar in total length to the multiple stented artery segment. Histological examination confirmed myointimal hyperplasia underlying in-stent stenosis. CONCLUSIONS: The multiple stent delivery system was studied in a porcine model, which demonstrated its feasibility. Preclinical experience revealed favourable results concerning stent fracture, restenosis, and patency of spot-stented femoropopliteal arteries.

CT-assisted transfemoral intrahepatic portosystemic shunt in a long duration follow-up: A case report.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension may be considered as a rescue therapy in case of recurrent variceal bleeding or failure of endoscopic management. CASE REPORTS: We present a case of a patient with massive gastroesophageal variceal bleeding refractory to numerous endoscopic treatments in which TIPS was considered in an attempt to decrease the risk of potentially fatal rebleeding. Standard TIPS procedure was not feasible due to altered anatomy of the liver resulting from right hemidiaphragmatic paresis. Computed Tomography (CT) fluoroscopic guidance was utilized for direct percutaneous puncture of the left hepatic and left portal vein with subsequent guidewire snaring to perform portosystemic shunting via femoral access. Since the procedure, no recurrent variceal bleeding was reported and the shunt remained patent at a 3-year follow-up. Although stent fracture with fragment migration was observed. CONCLUSIONS: Significant variation in liver anatomy does not preclude the creation of nonsurgical portosystemic shunt. In these cases, combined percutaneous and endovascular technique may be utilized.

[CME-Sonography 104: Angiomyolipomas]. / CME-Sonografie 104: Angiomyolipome.

CME-Sonography 104: Angiomyolipomas Abstract. Angiomyolipomas are the most common benign kidney tumors. Approximately 80 % are spontaneously occurring tumors, the majority <1.0 cm (approximately 54 %). These tumors do not grow and are harmless. Tumors between 1.0 and 2.5 cm (approx. 44 %) also very rarely grow and remain harmless. Larger tumors are rarely found (about 2 %). These must be carefully monitored, as tumors >4.0 cm can spontaneously manifest dangerous bleeding. Apart from spontaneous occurrence, there are also angiomyolipomas in the context of the tuberous sclerosis complex (TCS). Such tumors are often larger and combined with renal cysts and renal cell carcinomas. Measuring the of echo intensity is important for diagnosis.

Prevention of intraprocedural puncture site bleeding during arterial port implantation by use of a suture-mediated arterial closure system: a prospective randomized trial.

PURPOSE: To investigate a modified technique for arterial port placement that uses a suture-mediated closure system with the aim to reduce delays caused by intraprocedural oozing around the catheter. MATERIALS AND METHODS: Forty consecutive patients (age, 63.9 y ± 11.8) stratified for regional arterial infusion chemotherapy were prospectively randomized to undergo conventional or modified port implantation. Time for device placement, total procedure time, number of catheters, size of largest and final catheters placed, duration of bleeding from puncture site, procedural delays, and time until hemostasis was achieved were recorded. RESULTS: Time for device placement was 3.7 minutes ± 1.1, with no complications encountered. Total procedure times were 133.0 minutes ± 62.8 for conventional port implantation and 100.0 minutes ± 49.5 for modified implantation (P = .13). No differences were found in the number of catheters or size of largest or final catheter used. Duration of groin bleeding necessitating manual compression was 21.8 minutes ± 24.4 for conventional port implantation, resulting in a mean procedural delay of 6.2 minutes ± 7.0. Hemostasis was achieved after a mean of 17.1 minutes ± 20.9. Groin hematoma was observed in three patients. In contrast, with the modified technique, mean duration of oozing and intraprocedural delays were only 0.2 minutes ± 0.6 and 0.1 minutes ± 0.5, respectively (both P < .0001 vs conventional technique). Hemostasis was achieved within 3.2 minutes ± 4.1 (P < .0001), with no cases of hematoma found. CONCLUSIONS: Use of a suture-mediated closure system facilitated arterial port implantation by effective prevention of groin bleeding while allowing the use of a sheath.

European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 Clinical Practice Guideline for the Use of Minimally Invasive Treatments in Malignant Thyroid Lesions.

The growing detection of papillary thyroid microcarcinomas (PTMCs) is paralleled by an increase in surgical procedures. Due to the frequent indolent nature, cost, and risk of surgery, active surveillance (AS) and ultrasound-guided minimally invasive treatments (MITs) are in suitable cases of incidental PTMC proposed as alternatives to thyroidectomy. Surgery and radioiodine are the established treatments for relapsing cervical differentiated thyroid carcinoma (DTC) metastases. But radioiodine refractoriness, risk of surgical complications, adverse influence on quality of life, or declining repeat surgery have led to AS and MIT being considered as alternatives for slow-growing DTC nodal metastases. Also, for distant radioiodine-refractory metastases not amenable to surgery, MIT is proposed as part of a multimodality therapeutic approach. The European Thyroid Association and the Cardiovascular and Interventional Radiological Society of Europe commissioned these guidelines for the appropriate use of MIT. Based on a systematic PubMed search, an evidence-based approach was applied, and both knowledge and practical experience of the panelists were incorporated to develop the manuscript and the specific recommendations. We recommend that when weighing between surgery, radioiodine, AS, or MIT for DTC, a multidisciplinary team including members with expertise in interventional radiology assess the demographic, clinical, histological, and imaging characteristics for appropriate selection of patients eligible for MIT. Consider TA in low-risk PTMC patients who are at surgical risk, have short life expectancy, relevant comorbidities, or are unwilling to undergo surgery or AS. As laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective thermal ablation (TA) techniques, the choice should be based on the specific competences and resources of the centers. Use of ethanol ablation and high-intensity focused ultrasound is not recommended for PTMC treatment. Consider MIT as an alternative to surgical neck dissection in patients with radioiodine refractory cervical recurrences who are at surgical risk or decline further surgery. Factors that favor MIT are previous neck dissection, presence of surgical complications, small size metastases, and <4 involved latero-cervical lymph nodes. Consider TA among treatment options in patients with unresectable oligometastatic or oligoprogressive distant metastases to achieve local tumor control or pain palliation. Consider TA, in combination with bone consolidation and external beam radiation therapy, as a treatment option for painful bone metastases not amenable to other established treatments.

Common clonal origin of an acute B-lymphoblastic leukemia and a Langerhans' cell sarcoma: evidence for hematopoietic plasticity.

BACKGROUND: The hierarchical organization of hematopoiesis with unidirectional lineage determination has become a questionable tenet in view of the experimental evidence of reprogramming and transdifferentiation of lineage-determined cells. Clinical examples of hematopoietic lineage plasticity are rare. Here we report on a patient who presented with an acute B-lymphoblastic leukemia and developed a Langerhans' cell sarcoma 9 years later. We provide evidence that the second neoplasm is the result of transdifferentiation. DESIGN AND METHODS: B-cell acute lymphoblastic leukemia was diagnosed in an 11-year old boy in 1996. Treatment according to the ALL-BFM-1995 protocol resulted in a complete remission. Nine years later, in 2005, Langerhans' cell sarcoma was diagnosed in a supraclavicular lymph node. Despite treatment with different chemotherapy protocols the patient had progressive disease. Finally, he received an allogeneic peripheral blood stem cell transplant and achieved a continuous remission. Molecular studies of IGH- and TCRG-gene rearrangements were performed with DNA from the Langerhans' cell sarcoma and the cryopreserved cells from the acute B-lymphoblastic leukemia. The expression of PAX5 and ID2 was analyzed with real-time reverse transcriptase polymerase chain reaction. RESULTS: Identical IGH-rearrangements were demonstrated in the acute B-lymphoblastic leukemia and the Langerhans' cell sarcoma. The key factors required for B-cell and dendritic cell development, PAX5 and ID2, were differentially expressed, with a strong PAX5 signal in the acute B-lymphoblastic leukemia and only a weak expression in the Langerhans' cell sarcoma, whereas ID2 showed an opposite pattern. CONCLUSIONS: The identical IGH-rearrangement in both neoplasms indicates transdifferentiation of the acute B-lymphoblastic leukemia into a Langerhans' cell sarcoma. Loss of PAX5 and the acquisition of ID2 suggest that these key factors are involved in the transdifferentiation from a B-cell phenotype into a Langerhans'/dendritic cell phenotype. (Clinical trial registration at: Deutsches KrebsStudienRegister, http://www.studien.de, study-ID:8).

Early prediction of anticancer effects with diffusion-weighted MR imaging in patients with colorectal liver metastases following selective internal radiotherapy.

OBJECTIVE: To prospectively evaluate diffusion-weighted imaging (DWI) for early prediction of tumour response in patients with colorectal liver metastases following selective internal radiotherapy (SIRT). METHODS: We evaluated 41 metastases in 21 patients, age 62.9 ± 9.9 years. All patients underwent magnetic resonance imaging (MRI) including breath-hold echoplanar DWI sequences. Imaging was performed before therapy (baseline MRI), 2 days after SIRT (early MRI) as well as 6 weeks later (follow-up MRI). Tumour volume (TV) and intratumoural apparent diffusion coefficient (ADC) were measured independently by two radiologists at all time points. RESULTS: Metastases were categorised as responding lesions (RL; n = 33) or non-responding lesions (NRL; n = 8) according to changes in TV after 6 weeks. We found an inverse correlation of changes in TV and ADC at follow-up MRI with a Pearson's correlation coefficient of r = -0.66 (p < 0.0001). On early MRI, no significant changes in TV were found for either RL or NRL. Conversely, ADC decreased significantly in RL by 10.7 ± 8.4% (p < 0.0001). ADC increased in NRL by 9.6 ± 20.8%, which was not statistically significant (p = 0.40). CONCLUSION: DWI was capable of predicting therapy effects of SIRT in patients with colorectal hepatic metastases as early as 2 days following treatment.

Validation of VX2 as a Hepatocellular Carcinoma Model: Comparison of the Molecular Reaction of VX2 and HepG2 Tumor Cells to Sorafenib In Vitro.

As there is currently no superior hepatocellular carcinoma (HCC) model with percutaneous vascular access for transarterial treatments available, the VX2 rabbit model is frequently used for in vivo investigations on liver carcinoma. However, the VX2 cell line was derived from a virus-induced skin papilloma that can form carcinosarcoma in liver of rabbits and the transferability of obtained results to HCC treatment remains open. Here we compared the most frequently investigated human HCC model cell line, HepG2, with VX2 cells in vitro in terms of sensitivity towards the broad specificity kinase inhibitor sorafenib and responsiveness to the addition of platelet-derived growth factor AB (PDGF-AB), vascular endothelial growth factor (VEGF) and hepatic growth factor (HGF), as well as insulin and interleukin-1ß (IL1ß). Phosphorylation of protein kinase B (AKT) the mitogen-activated protein kinases (MAPKs) p38 and p42/44 (extracellular signal-regulated kinase, ERK1/2) and inhibitor of kappa light chain gene enhancer alpha (IĸBα) was determined by western blotting as these events are associated with early signaling cascades. Additionally, the inhibition of phosphorylation under sorafenib treatment was investigated. Sorafenib was equally toxic to both cell lines, but only in HepG2 was activation of caspase 3/7 activity, as a sign of apoptosis, observed. VX2 cells exhibited generally more intense phosphorylation signals in response to the growth factors and also serum. In contrast to VX2, HepG2 cells showed no response to PDGF-AB or VEGF as determined by kinase phosphorylation. In both cell lines, sorafenib inhibited growth factor-induced phosphorylation of ERK and p38-MAPK. AKT phosphorylation was only inhibited in VX2 cells and IĸBα phosphorylation was not influenced by this kinase inhibitor in either cell type. Taken together, the two cellular models for HCC share several features related to sorafenib application, but differed in their responsiveness towards growth factors. Therefore, results obtained with the VX2 model cannot be extended to human HCC without appropriate caution.

Local arterial infusion of superparamagnetic iron oxide particles in hepatocellular carcinoma: A feasibility and 3.0 T MRI study.

OBJECTIVES: We sought to prove feasibility of selective arterial infusion of superparamagnetic iron oxide (SPIO) particles in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: We studied 13 patients with HCC who underwent modified transarterial chemoembolization (TACE). Six patients received concurrent infusion of Ferucarbotran (Resovist, Schering, Berlin, Germany) in tumor-feeding arteries, and another 6 received MFL AS (MagForce, Nanotechnologies, Berlin, Germany). The iron content of both dispersions was 3.92 mg. One patient served as a control. All patients underwent magnetic resonance imaging (MRI) as baseline and immediate follow-up investigation. RESULTS: Selective arterial infusion of both SPIO particles resulted in significant intratumoral signal intensity decrease on T1-weighted sequences (P < 0.0001), which was greater after MagForce infusion compared with Resovist (P = 0.002). Only minimal amounts of dispersed particles were found in adjacent normal liver parenchyma. No change in intratumoral signal intensity was noted when ferromagnetic particles were omitted. CONCLUSIONS: Modified TACE with selective arterial infusion of SPIO particles can be used for precise tumor targeting in patients with HCC, for which MagForce appeared superior to Resovist.

Intrinsically radiopaque iodine-containing polyvinyl alcohol as a liquid embolic agent: evaluation in experimental wide-necked aneurysms.

OBJECT: To evaluate iodine-containing polyvinyl alcohol (I-PVA) as a precipitating liquid embolic agent, implant characteristics--including radiopacity, setting behavior, and biocompatibility--were studied in an aneurysm model in swine. METHODS: Twelve broad-based carotid artery (CA) sidewall aneurysms were surgically constructed in six pigs. Iodine-containing polyvinyl alcohol dissolved in dimethyl sulfoxide (DMSO) was injected during temporary balloon occlusion bridging the aneurysm neck. Control angiography as well as multidetector row computerized tomography (CT) angiography was performed after 4 weeks. Harvested aneurysms were investigated histopathologically and by 3-tesla high-field magnetic resonance (MR) imaging. The mean degree of aneurysm occlusion achieved was 96%. In two aneurysms a minimal protrusion of I-PVA into the CA lumen was observed. During one embolization, leakage of the liquid embolic agent due to DMSO-induced damage of the microcatheter resulted in CA occlusion. Aneurysms embolized with I-PVA could be discriminated clearly from the parent artery on CT angiograms because there was no beam-hardening artifact. High-field MR imaging allowed a detailed depiction of the liquid embolic distribution within the aneurysm. Histologically, a mild to moderate inflammatory response was found in successfully embolized aneurysms, and the polymer mass was frequently covered by a membrane of fibroblasts and endothelial cells. CONCLUSIONS: Iodine-containing polyvinyl alcohol is a ready-to-use liquid embolic agent clearly visible under fluoroscopy; additives are not required. The setting behavior allows for controlled delivery in aneurysm cavities. Histological studies performed 4 weeks after embolization revealed no sign of toxic tissue response to the liquid embolic agent. Overall, I-PVA exhibits interesting implant characteristics in that radiopaque admixtures are not necessary, thus allowing for artifact-free evaluation of treated aneurysms by using CT and MR angiography.

Modified transarterial chemoembolization with locoregional administration of sorafenib for treating hepatocellular carcinoma: feasibility, efficacy, and safety in the VX-2 rabbit liver tumor model.

PURPOSE: We aimed to assess the feasibility, efficacy and safety of a local application of sorafenib within a conventional transarterial chemoembolization in the VX-2 tumor-bearing rabbit model. METHODS: VX-2 tumors were induced in the left liver lobe of 10 New Zealand White rabbits. After two weeks, growth was verified by contrast-enhanced computed tomography (CT). Five rabbits were treated by transarterial chemoembolization using an emulsion of sorafenib and ethiodized oil (referred to as SORATACE; n=5). Rabbits receiving oral sorafenib for two weeks (n=2) and untreated rabbits (n=3) served as controls. After two weeks, contrast-enhanced CT was performed, followed by animal necropsy. RESULTS: The change in tumor diameter between baseline and follow-up was significantly different in the SORATACE group compared with the other groups; tumor shrinkage was observed in the SORATACE group only (P = 0.016). In both control groups, preserved hypervascularity was seen in the follow-up CT in all but one tumor. All tumors in the SORATACE group were devascularized in the follow-up CT. Importantly, substantial parenchymal damage in nontargeted areas of the tumor-bearing liver lobe was seen in rabbits treated with SORATACE. CONCLUSION: SORATACE demonstrated high efficacy in the treatment of experimental VX-2 liver tumors but was also associated with substantial liver parenchymal toxicity.

Role for reelin in the development of granule cell dispersion in temporal lobe epilepsy.

The reelin signaling pathway plays a crucial role during the development of laminated structures in the mammalian brain. Reelin, which is synthesized and secreted by Cajal-Retzius cells in the marginal zone of the neocortex and hippocampus, is proposed to act as a stop signal for migrating neurons. Here we show that a decreased expression of reelin mRNA by hippocampal Cajal-Retzius cells correlates with the extent of migration defects in the dentate gyrus of patients with temporal lobe epilepsy. These results suggest that reelin is required for normal neuronal lamination in humans, and that deficient reelin expression may be involved in migration defects associated with temporal lobe epilepsy.

Efficacy and safety of image-guided interstitial single fraction high-dose-rate brachytherapy in the management of metastatic malignant melanoma.

PURPOSE: Computed tomography (CT) or magnetic resonance imaging (MRI) guided brachytherapy provides high tumor control rates in hepatocellular carcinoma (HCC) and colorectal liver metastases. In contrast to thermal ablation methods such as radiofrequency ablation (RFA), much less restrictions apply with respect to tumor location or size. In this study, we determined the efficacy and safety of CT- or MRI-guided brachytherapy in metastatic melanoma. MATERIAL AND METHODS: Fifty-two metastases of malignant melanoma in 14 patients were included in this retrospective study. Local tumor control and safety were evaluated as primary and secondary endpoints. Furthermore, we evaluated overall survival and progression free survival. Tumor locations were liver (n = 31), lung (n = 15), adrenal (n = 3), lymph nodes (n = 2), and kidney (n = 1). Treatment planning was performed using three-dimensional CT or MRI data acquired after percutaneous applicator positioning under CT or open MRI guidance. Subsequently, single fraction high-dose-rate (HDR) brachytherapy was applied using a (192)Iridium source. Clinical and cross-sectional follow-up were performed every 3 months post intervention. RESULTS: The median diameter of treated lesions was 1.5 cm (range: 0.7-10 cm). Doses between 15 and 20 Gy were applied (median dose: 19.9 Gy). The mean irradiation time ranged between 7-45 minutes. After treatment, there was one patient with a cholangitis. After a median follow up of five months, the median local tumor control was 90%. The median overall survival of the patients was 8 months. The median progression free survival of the patients was 6 months. CONCLUSIONS: Image-guided HDR brachytherapy is a safe and effective treatment procedure in metastatic malignant melanoma.

Time-resolved perfusion imaging at the angiography suite: preclinical comparison of a new flat-detector application to computed tomography perfusion.

OBJECTIVES: The objective of this study was to compare the parameter maps of a new flat-panel detector application for time-resolved perfusion imaging in the angiography room (FD-CTP) with computed tomography perfusion (CTP) in an experimental tumor model. MATERIALS AND METHODS: Twenty-four VX2 tumors were implanted into the hind legs of 12 rabbits. Three weeks later, FD-CTP (Artis zeego; Siemens) and CTP (SOMATOM Definition AS +; Siemens) were performed. The parameter maps for the FD-CTP were calculated using a prototype software, and those for the CTP were calculated with VPCT-body software on a dedicated syngo MultiModality Workplace. The parameters were compared using Pearson product-moment correlation coefficient and linear regression analysis. RESULTS: The Pearson product-moment correlation coefficient showed good correlation values for both the intratumoral blood volume of 0.848 (P < 0.01) and the blood flow of 0.698 (P < 0.01). The linear regression analysis of the perfusion between FD-CTP and CTP showed for the blood volume a regression equation y = 4.44x + 36.72 (P < 0.01) and for the blood flow y = 0.75x + 14.61 (P < 0.01). CONCLUSIONS: This preclinical study provides evidence that FD-CTP allows a time-resolved (dynamic) perfusion imaging of tumors similar to CTP, which provides the basis for clinical applications such as the assessment of tumor response to locoregional therapies directly in the angiography suite.

Prophylactic embolization of the cystic artery prior to radioembolization of liver malignancies--an evaluation of necessity.

PURPOSE: Prior to radioembolization (RE) of hepatic tumors, many centers prophylactically occlude the cystic artery (CA) during evaluation angiography (EVA) to prevent radiation-induced cholecystitis. There is no conclusive evidence for the protective effect of CA embolization and it bears the risk of inducing ischemic cholecystitis. The aim of this study is to evaluate the justification for CA embolization by comparing clinical and morphologic imaging parameters between patients undergoing coil occlusion of the cystic artery (COCA) and those with uncoiled CA (UCCA). MATERIALS AND METHODS: Retrospective comparison of 37 patients with UCCA versus 68 patients with COCA in terms of clinical findings (CRP, leukocyte count, body temperature, upper abdominal pain) and morphologic imaging parameters associated with cholecystitis (gallbladder (GB) wall thickness, free fluid in GB bed, bremsstrahlung SPECT) after EVA, after RE, and at 6-week follow-up. RESULTS: At none of the 3 time points (EVA, RE, 6-week follow-up) was there any significant difference in CRP, leukocyte count, body temperature, or upper abdominal pain between the UCCA and COCA group. There was also no significant difference between the two groups with regard to GB wall thickness, fluid in the GB bed, and bremsstrahlung in SPECT. One patient of the UCCA group and two patients of the COCA developed cholecystitis requiring treatment. CONCLUSION: Comparison of clinical and imaging findings between patients with and without CA embolization prior to RE identified no predictors of radiogenic or ischemic cholecystitis after RE. Our study provides no evidence for a benefit of prophylactic CA embolization before RE.

The retrograde transvenous push-through method: a novel treatment of peripheral arteriovenous malformations with dominant venous outflow.

PURPOSE: To evaluate the efficacy and safety of a novel retrograde transvenous embolization technique of peripheral arteriovenous malformations (AVMs) using Onyx. MATERIALS AND METHODS: We conducted a retrospective analysis of all patients who underwent transvenous retrograde Onyx embolization of peripheral AVMs with dominant venous outflow over a 29-month period. The embolization is aimed at retrograde filling of the nidus after building a solid plug in the dominant venous outflow (push-through). Classification, clinical signs, technical aspects, clinical and technical success rates, and complications were recorded. Short-term outcome was assessed. RESULTS: 11 Symptomatic patients (8 female; mean age 31.4 years) were treated at our Vascular Anomalies Center with this method between January 2012 and May 2014. The AVMs were located on the upper extremity (n = 3), pelvis (n = 2), buttock (n = 2), and lower extremity (n = 4). Retrograde embolization was successfully carried out after preparatory transarterial-flow reduction in eight cases (73 %) and venous-flow reduction with Amplatzer Vascular Plugs in four cases (36 %). Complete devascularization (n = 10; 91 %) or 95 % devascularization (n = 1; 9 %) led to complete resolution (n = 8; 73 %) or improvement of clinical symptoms (n = 3; 27 %). One minor complication occurred (pain and swelling). During a mean follow-up time of 8 months, one clinically asymptomatic recurrence of AVM was detected. CONCLUSION: Initial results suggest that retrograde transvenous Onyx embolization of peripheral AVMs with dominant venous outflow is a safe and effective novel technique with a low complication rate.

Development of a complex dural arteriovenous fistula next to a cerebellar developmental venous anomaly after resection of a brainstem cavernoma. Case report and review of the literature.

Developmental venous anomalies (DVAs) are common abnormalities of intracranial venous drainage, which may occur in conjunction with other cerebral vascular malformations and are known for their benign natural history. The authors present the case of a 16-year-old boy who experienced a spontaneous brainstem hemorrhage due to a cavernoma. Preoperative angiography findings revealed a large DVA draining the right cerebellar hemisphere. The patient underwent suboccipital surgery for cavernoma resection and recovered completely from his neurological symptoms. Fourteen months later he returned with progressive symptoms. Repeated angiography demonstrated a complex dural arteriovenous fistula (DAVF) of the transverse sinus, which had developed next to the DVA. Several transarterial and transvenous embolizations were ineffective. Common causes of acquired DAVFs and the potential role of the DVA in the development of the DAVF in this case are discussed on the basis of the pertinent literature.

Safety and efficacy of target vessel catheterization with the new steerable microcatheter Direxion compared with a standard microcatheter: a prospective, preclinical trial.

PURPOSE: To assess the potential of a steerable microcatheter in a comparative preclinical trial. METHODS: A total of 100 small target vessels of the lower limbs with a maximum diameter of 3 mm were prospectively randomized to catheterize with either the preshaped torqueable Direxion™ (J tip shape; Boston Scientific, Natick, MA) or a similarly steam-shaped Renegade™ microcatheter (Boston Scientific) in a porcine model. Catheterization was first performed in combination with a microguidewire and afterwards without. RESULTS: No significant differences were found for the mean vessel diameter in the Direxion (1.53 ± 0.44 mm; n = 50) or Renegade (1.62 ± 0.43 mm; n = 50; p = 0.35) group. Guidewire-assisted catheterization was successful in all target vessels, whereas access was achieved in most cases with the guidewire alone. However, when it became necessary to steer the Direxion actively, this was regarded as key to obtain vessel access in three of four target vessels (75 %). Vessel catheterization without guidewire was significantly more successful with the Direxion (88 %; n = 44) compared with the Renegade (32 %; n = 16; p < 0.0001). In addition, this catheterization technique was also significantly faster with the Direxion compared with guidewire-assisted vessel catheterization with the Renegade (16.1 ± 14.4 sec compared with 27.1 ± 24.7 sec; p = 0.011). CONCLUSIONS: The Direxion microcatheter demonstrated unique steerability characteristics, which makes it a promising new tool especially for complex coaxial endovascular procedures.

Is There Any Evidence for a Role of Local Treatment in Cholangiocarcinoma?

BACKGROUND: Most cholangiocarcinomas (CCA) are locally advanced and unresectable at the time of diagnosis. Currently, chemotherapy combining gemcitabine with a platinum agent is the recommended first-line treatment regimen for advanced biliary tract cancer. However, median overall survival is only approximately 1 year. As the hepatic tumor burden is the limiting factor for the prognosis of these patients, local tumor control is essential. METHODS: We present and discuss the current evidence for such therapy options for patients with CCA. RESULTS: Local and locoregional therapies have been shown to be well tolerated and can contribute to tumor control in the context of a comprehensive oncologic treatment strategy, and may prolong survival of patients with advanced CCA. Unfortunately, only few high-quality clinical trials are available. CONCLUSION: Randomized prospective clinical trials enrolling larger numbers of patients need to be carried out to elucidate the precise value of these treatments alone as well as in combination with systemic chemotherapy.