Particle Embolization Research Articles

Effectiveness of partial splenic embolization in colorectal cancer patients with chemotherapy-induced thrombocytopenia: results of a single institution retrospective study.

To evaluate the safety and efficacy of partial splenic embolization (PSE) in treating chemotherapy-induced thrombocytopenia (CIT) in patients with colorectal cancer who failed to respond to platelet growth factor therapy. 56 patients who underwent PSE were retrospectively analyzed. Based on the inclusion and the exclusion criteria, 29 patients were eligible for the study, of whom one underwent twice PSE procedures due to recurrent thrombocytopenia. The clinical characteristics were retrospectively analyzed with respect to efficacy, safety and outcome. 60.0% of patients restarted antineoplastic therapy after PSE. There was a positive correlation between difference value of platelet count and embolization material size (Eta Squared = 0.252, p < 0.05). The correlation between the absolute volume of spleen embolized and postoperative complications was analyzed, with a statistically significant result (p < 0.001). The mean preoperative spleen volume, the preoperative platelet count, postoperative platelet count and difference value of platelet count in the non-cirrhotic group were larger than those in the cirrhotic group (p < 0.001). The mean overall survival was 47.7 ± 7.7 months. PSE is safe and effective in the treatment of CIT patients with colorectal cancer. The larger the embolized particle, the more platelets grew. The severity of complication was also positively correlated with the absolute volume of spleen embolized. Therefore, large particle embolization materials can be used to improve the efficacy of PSE and reduce complications. For CIT patients with cirrhosis, PSE was less effective in improving platelet count than those without cirrhosis.

8113 Thyroid Storm in a Patient with Thyroid Nodule on Anticoagulation

Abstract Disclosure: R. Kulkarni: None. S.S. Krishnasamy: None. N. Mon: None. R. Downs: None. Background: There are very few case reports related to hyperthyroidism due to anticoagulation use. We describe a case, of a less common cause of hyperthyroidism due to hemorrhagic thyroiditis in a patient on anticoagulation and history of metastatic colon cancer. Clinical case: A 67-year-old white male with PMH significant for colon cancer with liver metastasis s/p exploratory laparotomy with sigmoid colectomy, end-colostomy with Hartman's pouch creation, pre-diabetes, recent left IJ &amp; axillary vein thrombus on Eliquis, and thyroid nodule; presented with complaints of shortness of breath, difficulty swallowing and dizziness. Other symptoms included weight loss, complaints of heart racing and generalized body aches. The patient had a recent admission for similar complaints and was newly diagnosed with left IJ/axillary vein thrombus and expanding hemorrhagic thyroid nodule on imaging. He was discharged on anticoagulation for the DVT with 2 week follow up for elective thyroidectomy for goiter. The patient was admitted to the ICU for worsened respiratory status needing ventilatory support and pressor support. Physical findings on admission included jaundice, sinus tachycardia, lethargy with agitation. Initial labs showed TSH 0.02 uIU/mL, FT4 4.85 ng/dL and FT3 6.8 pg/mL, LFTs &amp;gt;500 U/L. Burch-Wartofsky Point Scale score was &amp;gt;60 suggestive of thyroid storm. Imaging with PET CT was concerning for thyroid enlargement with multiple nodules with increased uptake. Thyroid US was consistent with heterogenous gland with hemorrhagic nodules. Based on clinical history, physical findings, diagnostic labs, and imaging the patient was diagnosed with severe hyperthyroidism with thyroid storm secondary to hemorrhagic thyroid nodules in the setting of anticoagulation. The patient underwent thyroid artery angiogram with particle embolization of left inferior and right superior thyroid arteries. Endocrinology started the patient on methylprednisolone, cholestyramine and propranolol. Thionamide was held since the patient had abnormal liver function tests in the setting of shock liver. The patient’s thyroid function slowly improved on current regimen to TSH 0.05 uIU/mL, FT4 1.7 ng/Dl and FT3 4.1 pg/mL on day 3. At the family interdisciplinary meeting, due to guarded prognosis, family opted for comfort care, and the patient finally succumbed to multiple co-morbidities. Conclusion: The case presented discusses diagnosis and management of less common causes of hyperthyroidism and management of thyroid storm in liver dysfunction. The patient would have needed a thyroid biopsy at a later date to rule out colonic metastasis as a cause of hemorrhage if he had survived the thyroid storm and comorbid illnesses. Presentation: 6/3/2024

The Influence of Preablation Embolization Particle Size on the Size of the Microwave Ablation Zone in a Porcine Orthotopic Renal Tumor Model

PurposeTo combine arterial embolization with different embolic agents, followed by microwave ablation (MWA) in a porcine renal tumor (RT), to evaluate the ideal setting to produce the largest change in the size of the ablation zones (AZs). Materials and MethodsIn a transgenic porcine kidney, 32 sites were inoculation with 28 orthotopic RT produced. Experimental groups (23 tumors) underwent angiography with intra-arterial embolization using various embolic materials (calibrated particles from 40 to 1,200 μm and ethiodized oil) to achieve vascular stasis of the RT. MWA using a standard protocol (3 minutes at 65 W) was subsequently performed for all tumors. Next, a gross and histologic ex vivo analysis of the AZ was performed. ResultsControl group AZ volume without prior embolization was 5.24 cm3 (SD ± 0.55). AZs after embolization with 40 μm, 100 μm, 300–500 μm, 900–1,200 μm particles were significantly larger than those with MWA alone (mean, 15.39 cm3 [SD ± 4.54]; P = .002; 11.07 cm3 [SD ± 1.39]; P = .001; 8.68 cm3 [SD ± 0.77]; P = .001; and 9.90 cm3 [SD ± 1.62]; P = .002, respectively). Liquid embolic ethiodized oil emulsion did not create a significant increase in the AZ (5.92 cm3 [SD ± 1.43 cm3]; P = .492). ConclusionsPre-MWA arterial embolization in a porcine RT model produced a statistically significant increase in the AZ when compared with MWA alone. Using smaller particle size embolic material with distal embolization at the tumor arterioles (50–150 μm) produced the largest, almost 3-fold increase in AZ volume.

Comparing embolic particles for prostatic artery embolization to treat lower urinary tract symptoms in patients with benign prostatic hyperplasia.

Compare the safety and efficacy of polyvinyl alcohol particles (PVA) versus trisacryl gelatin microspheres (Embospheres) versus hydrogel microspheres coated with polyzene-F (Embozenes) for prostatic artery embolization (PAE) to treat patients with benign prostatic hyperplasia (BPH). A single-center prospective cohort study from 2019 to 2023, including patients with international prostate symptom score (IPSS) ≥ 15 and/or quality of life score (QoL) ≥ 4. Allocation to embolic agents was performed chronologically: 100-300 µm PVA (n = 53), followed by 300-500 µm Embospheres (n = 50), and finally, 400 µm Embozenes (n = 50). All patients were evaluated at baseline and at 1 and 6 months after PAE with IPSS/QoL; peak urinary flow rate, post-void residual volume, and prostate volume with ultrasound and prostate-specific antigen. Adverse events and the need for prostatic re-interventions were assessed. There were no significant baseline differences between the three groups except for patient age (62.5 years PVA; 66.1 years Embospheres and 66.6 years Embozenes; p = 0.019). There were no major adverse events and no differences between groups regarding minor adverse events. All outcome measures improved significantly from baseline, with no significant differences between groups. Mean ± standard deviation IPSS/QoL improvement at 6 months: -10.7 ± 7.9/-2.2 ± 1.7 PVA; -10.4 ± 7.3/-2.0 ± 1.5 Embospheres; -10.4 ± 7.0/-2.2 ± 1.6 Embozenes (p = 0.987). Re-intervention rates after 6 months: 9% (n = 5/53) PVA; 14% (n = 7/50) Embospheres; 8% (n = 4/50) Embozenes (p = 0.591). PAE with PVA particles, Embospheres, and Embozenes is equally safe and effective in treating BPH-related lower urinary tract symptoms. This is the first prospective study showing equivalence between the most frequently used embolic agents for prostatic artery embolization. Different particles can be used interchangeably for prostatic artery embolization. The improvements in measured metrics were the same between groups, with no differences in adverse events. The need for prostatic medication and re-intervention rates were the same at 1 and 6 months after embolization.

Embolization of the Pancreas Using Microspheres: A Proof-of-Safety Study in a Porcine Model

PurposeTo evaluate safety and impact of particle embolization on pancreatic function in a pig model. Materials and MethodsEmbolization of the dorsal pancreatic artery using 100–300-μm particles was performed on 14 Yorkshire pigs. Baseline and post-embolization glucose tolerance testing results and serum amylase/lipase levels were obtained. Pigs were observed for 2 weeks to assess for behavioral signs of pain/distress, bowel changes, and changes to intake/output. After 2 weeks, euthanasia and necropsy with gross and histopathologic assessment of the pancreas were performed. ResultsEmbolization was technically successful in all pigs. All animals survived the 2-week follow-up without evidence of pain/distress. There were significant increases in amylase and lipase at 24 and 48 hours (P < .001), which normalized by 2 weeks. There was minimal change in glucose tolerance testing at 2 weeks. Bowel habits were unchanged without diarrhea. At necropsy, all examined pancreases had fibrosis in the distal body and tail, without gross evidence of ongoing inflammation. On histopathologic evaluation, all pancreases demonstrated fibrosis in the embolized portions without evidence of active inflammation in treated or adjacent pancreatic tissue. ConclusionsParticle embolization of the pancreas was feasible and tolerated by all tested pigs with transient amylasemia, lipasemia, and mildly impaired glucose tolerance but without clinical or histopathologic evidence of acute pancreatitis and no evident impact on pancreatic endocrine or exocrine function.

Comparing Deposition Characteristics of Various Embolic Particles Using an In Vitro Prostate Microvasculature Model

PurposeTo compare spatial distributions of radiopaque glass (RG) microspheres, tris-acryl gelatin (TAG) microspheres, and polyvinyl alcohol (PVA) nonspherical foam particles within a planar in vitro microvascular model of the hyperplastic hemiprostate. Materials and MethodsA microvascular model simulating hyperplastic hemiprostate was perfused with a water-glycerin mixture. A microcatheter was positioned distal to the model’s prostatic artery origin, and embolic particles (RG, 50 μm, 100 μm, and 150 μm; TAG, 100–300 μm and 300-500 μm; and PVA, 90–180 μm and 180–300 μm) were administered using a syringe pump. Microscopic imaging and subsequent semantic segmentation were performed to quantify particle distributions within the models. Distal penetrations were quantified statistically via modal analysis of the particle distributions. ResultsMaximum distal penetration was observed for RG microspheres of 50 μm, followed by RG microspheres of 100 μm and then TAG microspheres of 100–300 μm and RG microspheres of 150 μm. TAG microspheres of 300–500 μm, PVA particles of 90–180 μm, and PVA particles of 180–300 μm exhibited the lowest distal penetrations. The distal penetration metrics between groups were significantly different (P < .05) except between TAG microspheres of 100–300 μm and RG microspheres of 150 μm and between PVA particles of 90–180 and 180–300 μm. ConclusionsComparing the spatial distributions of embolic particles in an in vitro microvascular model simulating the hyperplastic hemiprostate revealed that noncompressible particles and those with narrower size calibrations and smaller relative diameters exhibited higher degrees of distal packing. The embolization front was less distinct for particles with wider size calibrations, which resulted in smaller, more distal emboli along with larger, more proximal emboli. Both PVA particles and TAG microspheres of 300–500 μm exhibited relatively low overall distal penetration.

Preoperative Embolization of Intracranial Meningioma

Preoperative embolization(POE)of intracranial meningioma is performed worldwide. Although clear evidence of the effectiveness of POE has not been reported in the literature, the technique plays an important role in open surgery, especially for large or skull base meningiomas. The purposes of embolization include: 1)induction of tumor necrosis, resulting in a safer operation, 2)reduction in intraoperative bleeding, and 3)decrease in operative time. Knowledge of the functional vascular anatomy, embolic materials, and endovascular techniques is paramount to ensure safe embolization. Our standard procedure is as follows: 1)embolization is performed several days before open surgery; 2)in cases with strong peritumoral edema, steroid administration or embolization may be performed immediately prior to surgery; 3)patients undergo the procedure under local anesthesia; 4)the microcatheter is inserted as close as possible to the tumor; 5)particulate emboli are the first-line material; 6)embolization is occasionally performed with N-butyl cyanoacrylate(NBCA)glue; and 7)if possible, additional proximal feeder occlusion with coils is performed. The JR-NET study previous showed the situation regarding intracranial tumor embolization in Japan. Endovascular neurosurgeons should fully discuss the indications and strategies for POE with tumor neurosurgeons to ensure safe and effective procedures.

Abscopal effect after bronchial artery embolization for cancer-related hemoptysis

AbstractThe abscopal effect, a rare phenomenon in cancer treatment, involves tumor regression in a distant location from the targeted therapy. This case focuses on a 74-year-old woman with metastatic papillary thyroid cancer. Despite prior treatments, she experienced pulmonary nodule progression and hemoptysis. Bland particle embolization was performed on the right bronchial artery branches supplying lung metastases, leading to significant reductions in size, number, and metabolic activity of the right-sided nodules and decreased metabolic activity of the untreated left-sided nodules, without additional cancer-related treatments. The abscopal effect has been observed with various interventional oncologic procedures, indicating a potential role in stimulating the immune response and altering the tumor microenvironment. Further investigation is needed to understand bland embolization's immunomodulatory effects and implications for triggering the abscopal effect.

Efficacy and safety of particle embolization in bronchial arteries of hemoptysis patients with shunts

This study assesses the safety and efficacy of particle embolization during bronchial artery embolization (BAE) in patients with shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery. In this retrospective, single-center study, we analyzed 312 BAE procedures performed from June 2020 to April 2023. The patient cohort had shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery. We meticulously collected and examined comprehensive data, including clinical characteristics, computed tomography (CT) imaging, and embolization procedural details. Vascular shunts were identified in 49 patients. The etiologies of hemoptysis included post-TB sequelae (42.8%), bronchiectasis (26.5%), active TB (12.2%), aspergilloma (8.1%), bacterial pneumonia (4.1%), lung cancer (4.1%), and non-tuberculous mycobacterial infection (2%). The technical success rate of the procedures was 98%, with 149 out of 152 identified vessels successfully embolized. All patients experienced cessation or significant reduction of hemoptysis within 24 hours following the procedure. The clinical success rates were 97.9% at one month, 93.9% at six months, and 89.8% at one year. No shunt-related complications were detected. BAE with particle embolization is a safe and effective treatment for hemoptysis, particularly in cases with complex shunts between bronchial and non-bronchial systemic arteries and the pulmonary artery.

Potential microemboli formation risk and its management during the heated saline–enhanced radiofrequency needle-tip catheter ablation

BackgroundThe potential risk of embolic events during ablation in the left ventricle (LV) with a heated saline–enhanced radiofrequency (SERF) needle-tip ablation catheter has not been characterized. ObjectiveThis study aimed to investigate the formation of microemboli or other untoward events during SERF ablation. MethodsNinety-three radiofrequency (RF) ablation procedures were performed in the LV of 14 pigs by using a SERF catheter (35 W, 70 seconds, and 60°C; normal or degassed saline [NS or DS] irrigation with a flow rate of 10 mL/min) vs a standard irrigated-tip radiofrequency (S-RF) catheter (30 or 50 W, 30 seconds, and 17 mL/min). Microbubble formation was graded on the basis of intracardiac echocardiography. Microbubbles, microembolic signals, and microparticles were monitored using our established model. ResultsThere was no significant difference in microbubble volume among SERF-NS, SERF-DS, and S-RF 30 W with “grade 1” intracardiac echocardiography microbubbles (median and 25th–75th percentiles 0.201 [0.011–3.13], 0.455 [0.06–2.66], and 0.004 μL [0.00–0.16 μL], respectively). There was no significant difference in microembolic signals among SERF-NS, SERF-DS, and S-RF 30 W with grade 1 bubbles (n = 8.0 ± 5.8, n = 7.6 ± 4.2, and n = 6.1 ± 6.1, respectively). Both SERF-NS and SERF-DS created larger lesions than did both S-RF 30 W and S-RF 50 W deliveries (mean 1241.5 ± 658.6, 1497.7 ± 893.4, 75.0 ± 24.8, and 184.0 ± 93.8 mm3; P < .001). There was no significant difference in microparticle incidence among groups (P = .675). No evidence of embolic events was found in the brain and other organs at the histology assessment. ConclusionIn the setting of SERF ablation, significantly large LV lesions can be created without any increment in embolic microbubble or particle events. Grade 1 microbubble is related to the efficacy and safety.

Abstract 3021: An Examination Of Emerging Techniques Forquantification Of Systemic-to-pulmonary Collateral Vessel Burden Using Imaging Modalities

Introduction: The quantification of systemic-to-pulmonary collateral vessels (SPCs) and their effects on hemodynamics is a subjective standard that has been intriguing for physicians due to the implications they could have; in cases where there is significant collateral burden, occlusion of these SPCs may be desirable, though this can present with a risk of stroke due to errant embolization particles. No benchmark method of SPC flow assessment has been established. Quantitative analysis of systemic and pulmonary flow values is possible through the use of computational fluid dynamics (CFD). CFD models can provide advanced and accurate analysis of cardiovascular hemodynamics providing more information beyond routine imaging. Hypothesis: Current methods for quantifying SPC burden are inadequate and could be improved through the use of additional CFD analysis. Methods: A PubMed and Science Direct search was performed. Select inclusion and exclusion criteria were applied to search results. Results: The search resulted in a total of 155 unique articles. Of these, 94 articles were found to meet inclusion criteria, and 54 articles were settled on after reviewing articles for further exclusion criteria. Seven articles discussed the use of CT and catheterization for quantifying collateral burden while 43 described using MRI to provide flow values. Eight articles mentioned the use of CFD to quantify hemodynamics in patients with SPCs, and 25 articles provided specific formulas for collateral flow. Conclusions: Using cardiac magnetic resonance velocity mapping is currently regarded as the best method for quantifying SPC burden. The incorporation of CFD analysis with flow data acquired with CMR may be useful in simulating the effects of SPC burden prior to any intervention as well as in predicting the effects of SPC occlusion on patient hemodynamics.

Genicular artery embolization for the treatment of knee pain secondary to mild to severe knee osteoarthritis: One year clinical outcomes

ObjectiveTo evaluate the safety and efficacy of genicular artery embolization (GAE) in patients with mild-to-severe knee osteoarthritis up to 12 months after GAE. Materials & methodsThis prospective single-center study included patients who had knee osteoarthritis for >1 year with moderate-to-severe pain after failed conservative treatment for >6 months. Baseline imaging features were evaluated to determine Kellgren-Lawrence (KL) grade and magnetic resonance imaging (MOAKS) scores. GAE was performed using 150–350 μm embolic polyvinyl alcohol particles. The visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were used to evaluate knee pain, stiffness, and function at baseline and follow-up. The primary endpoints were changes in VAS and WOMAC scores at 12 months. ResultsThirty-three patients (n = 37 knees) aged 66.6 ± 8.7 years were enrolled. The patients were categorized into two groups: mild-to-moderate osteoarthritis (n = 28, KL grades 2–3) and severe osteoarthritis (n = 9, KL grade 4). GAE was successfully performed in all patients, with no major adverse events. Three to six branches of the genicular artery were embolized. The mean VAS and WOMAC scores in the mild-to-moderate group significantly decreased (6.6 at baseline vs. 3.0 at 12 months and 49.4 vs. 27.4, respectively, all P < 0.001). The mean VAS and WOMAC scores in the severe group significantly decreased at 12 months (7.3 vs. 4.4 and 58.1 vs. 40.6, respectively, all P < 0.001). ConclusionGAE is a well-tolerated and effective treatment that significantly improves pain symptoms and function in patients with mild-to-severe knee osteoarthritis.

Simple coiling of middle meningeal artery embolization for chronic subdural hematoma: An inverse probability of treatment weighting matched cohort study.

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) has gained much attention in recent years. However, unintended embolization may occur when employing liquid embolic agents or particles. We present our clinical experience in simple coiling of MMAE to manage CSDH. Patients underwent either surgical evacuation or MMAE with simple coiling for CSDH were reviewed. Clinical and radiographic outcomes were assessed at admission, 1-month, and 6-month intervals. Two treatment groups were matched with inverse probability of treatment weighting. One hundred twelve patients were included, with 27 patients in MMAE group and 87 patients in surgery group. In MMAE group, significant reductions were observed in hematoma width (admission vs. 1-month, 2.04 [1.44-2.60] cm vs. 0.62 [0.37-0.95] cm, p < 0.001). The adjusted odds ratio (aOR) of surgical rescue rate (0.77 95%CI 0.13-4.47, p = 0.77), hematoma reduction (>50%) (0.21 95%CI 0.04-1.07, p = 0.06), and midline shift improvement rate (3.22, 95%CI 0.84-12.4, p = 0.09) had no substantial disparities between two groups at 1-month follow-up. In addition, no significant difference was noted between two groups in terms of hematoma reduction (>50%) at 6-month follow-up (aOR 1.09 95%CI 0.32-3.70, p = 0.89). No procedure-related complications were found in MMA embolization group. Simple coiling for MMA had comparable outcomes with surgical evacuation for CSDH. Our findings suggest that simple coiling can be an alternative choice for liquid agents or particles in MMA embolization for CSDH with acceptable safety.

Abstract WP214: Embolization in Chronic Subdural Hematomas

Introduction: Middle meningeal artery embolization for chronic subdural hematomas is a promising treatment either as an adjuvant to surgical evacuation of the hematoma or as a primary treatment modality. Current randomized trials are ongoing, but there is a lack of clarity as to which embolic agent may be more effective in preventing hematoma expansion. The current study examines if there is a difference between particle and liquid embolic agents for this indication. Methods: This is a single center retrospective study from May 2019- May 2023 where 160 consecutive patients with chronic subdural hematomas were treated with embolization. In August 2021, operators at our institution switched from using NCBA or Onyx to Embospheres. We analyzed if there were differences in complication rates, requirement for surgery after embolization and changes in 90 day CT imaging with regards to resolution. A Fisher’s exact chi square test was used for binary variables and student’s t-test for continuous variables. Results: A total of 160 patients were treated with embolization and the mean age was 71± 11 years with 45 (28%) presenting with bilateral subdural hematomas. The mean maximal diameter of the collection was 16.3 ± 6.6 mm and midline shift of 4.8±4.4 mm. A total of 67 patients (42%) were treated with particles and 93(58%) with liquid embolic agents. There was one patient with facial nerve palsy in the liquid embolic group and one patient with transient vision symptoms and three with post procedural seizures in the particle embolization group. More patients treated with liquid embolic agents were on anti-platelets or anti-coagulants compared to the particle group (34% vs. 16%, p&lt;0.01). There was no difference in requirement of surgery between the two groups (3.2% vs. 1.4%, p&lt;0.49). Both groups had similar reduction of the maximal diameter with no difference noted at 90 days (3.9 vs. 4.4 mm, p&lt;0.59). Conclusions: The current analysis provides preliminary evidence of the safety of both agents and no difference in outcomes noted between the two groups. A well designed future randomized trial would be helpful given the cost differences between the two types of agents.

Tumor Embolization via the Meningohypophyseal and Inferolateral Trunk in Patients with Skull Base Tumors Using the Distal Balloon Protection Technique.

Tumor embolization through the meningohypophyseal trunk and inferolateral trunk is known to be effective in skull base tumors; however, microcatheter cannulation into these arteries is difficult, and the number of cases that can be safely embolized is limited. In this study, we present a novel embolization procedure for the meningohypophyseal trunk and inferolateral trunk using the distal balloon protection technique and detail its clinical efficacy and complication risks. We developed this procedure to allow safe embolization in patients who cannot be adequately cannulated with microcatheters into these arteries. Patients who underwent meningohypophyseal trunk or inferolateral trunk embolization using the distal balloon protection technique for skull base tumors at our institution between 2010 and 2023 were included. In this procedure, the ICA was temporarily occluded with a balloon at the ophthalmic artery bifurcation, the microcatheter was guided to the meningohypophyseal trunk or inferolateral trunk vicinity, and embolic particles were injected into the arteries. The balloon was deflated after the embolic particles that had refluxed into the ICA were aspirated. A total of 25 meningohypophyseal trunks and inferolateral trunks were embolized during 21 operations. Of these 25 arteries, only 9 (36.0%) were successfully cannulated with microcatheters. Nevertheless, effective embolization was achieved in all cases. Permanent complications occurred in only 1 case (4.8%) in which the central retinal artery was occluded during inferolateral trunk embolization, resulting in a visual field defect. No permanent complications resulting from the embolic cerebral infarction were observed. Of 16 cases that underwent MR imaging within a week after embolization, however, 11 (68.8%) demonstrated embolic cerebral infarctions. In patients with skull base tumors with meningohypophyseal trunk or inferolateral trunk feeders that cannot be catheterized directly, embolization using the distal balloon protection technique for tumor supply can be considered as a salvage technique.

Fat embolism: the hidden murder for trauma patients!

fat embolism syndrome (FES) is an acute respiratory disorder that occurs when an inflammatory response causes the embolization of fat and marrow particles into the bloodstream. The exact incidence of FES is not well defined due to the difficulty of diagnosis. FES is mostly associated with isolated long bone trauma, and it is usually misdiagnosed in other trauma cases. The scope of this study was to identify and search the current literature for cases of FES in nonorthopedic trauma patients with the aim of defining the etiology, incidence, and main clinical manifestations. we perform a literature search via the PubMed journal to find, summarize, and incorporate reports of fat embolisms in patients presenting with non-orthopedic trauma. the final literature search yielded 23 papers of patients presenting with fat embolism/FES due to non-orthopedic trauma. The presentation and etiology of these fat embolisms is varied and complex, differing from patient to patient. In this review, we highlight the importance of maintaining a clinical suspicion of FES within the trauma and critical care community. to help trauma surgeons and clinicians identify FES cases in trauma patients who do not present with long bone fracture, we also present the main clinical signs of FES as well as the possible treatment and prevention options.

Spatiotemporal frequency domain analysis for blood velocity measurement during embolization procedures.

Currently, determining procedural endpoints and treatment efficacy of vascular interventions is largely qualitative and relies on subjective visual assessment of digital subtraction angiography (DSA) images leading to large interobserver variabilities and poor reproducibility. Quantitative metrics such as the residual blood velocity in embolized vessel branches could help establish objective and reproducible endpoints. Recently, velocity quantification techniques based on a contrast enhanced X-ray sequence such as qDSA and 4D DSA have been proposed. These techniques must be robust, and, to avoid radiation dose concerns, they should be compatible with low dose per frame imageacquisition. To develop and evaluate a technique for robust blood velocity quantification from low dose contrast enhanced X-ray image sequences that leverages the oscillating signal created by pulsatile bloodflow. The proposed spatiotemporal frequency domain (STF) approach quantifies velocities from time attenuation maps (TAMs) representing the oscillating signal over time for all points along a vessel centerline. Due to the time it takes a contrast bolus to travel along the vessel centerline, the resulting TAM resembles a sheared sine wave. The shear angle is related to the velocity and can be determined in the spatiotemporal frequency domain after applying the 2D Fourier transform to the TAM. The approach was evaluated in a straight tube phantom using three different radiation dose levels and compared to ultrasound transit-time-based measurements. The STF velocity results were also compared to previously published approaches for the measurement of blood velocity from contrast enhanced X-ray sequences including shifted least squared (SLS) and phase shift (PHS). Additionally, an in vivo porcine study (n = 8) was performed where increasing amounts of embolic particles were injected into a hepatic or splenic artery with intermittent velocity measurements after each injection to monitor the resulting reduction invelocity. At the lowest evaluated dose level (average air kerma rate 1.3 mGy/s at the interventional reference point), the Pearson correlation between ultrasound and STF velocity measurements was . This was significantly higher ( ) than corresponding correlation results between ultrasound and the previously published SLS and PHS approaches ( and , respectively). In the in vivo study, a reduction in velocity was observed in of cases after injection of 1 mL, after 3 mL, and after 4 mL of embolicparticles. The results show good agreement of the spatiotemporal frequency domain approach with ultrasound even in low dose per frame image sequences. Additionally, the in vivo study demonstrates the ability to monitor the physiological changes due to embolization. This could provide quantitative metrics during vascular procedures to establish objective and reproducibleendpoints.

Polymeric Microspheres Designed to Carry Crystalline Drugs at Their Surface or Inside Cavities and Dimples.

Injectable polymer microparticles with the ability to carry and release pharmacologically active agents are attracting more and more interest. This study is focused on the chemical synthesis, characterization, and preliminary exploration of the utility of a new type of injectable drug-releasing polymer microparticle. The particles feature a new combination of structural and physico-chemical properties: (i) their geometry deviates from the spherical in the sense that the particles have a cavity; (ii) the particles are porous and can therefore be loaded with crystalline drug formulations; drug crystals can reside at both the particle's surfaces and inside cavities; (iii) the particles are relatively dense since the polymer network contains covalently bound iodine (approximately 10% by mass); this renders the drug-loaded particles traceable (localizable) by X-ray fluoroscopy. This study presents several examples. First, the particles were loaded with crystalline voriconazole, which is a potent antifungal drug used in ophthalmology to treat fungal keratitis (infection/inflammation of the cornea caused by penetrating fungus). Drug loading as high as 10% by mass (=mass of immobilized drug/(mass of the microparticle + mass of immobilized drug) × 100%) could be achieved. Slow local release of voriconazole from these particles was observed in vitro. These findings hold promise regarding new approaches to treat fungal keratitis. Moreover, this study can help to expand the scope of the transarterial chemoembolization (TACE) technique since it enables the use of higher drug loadings (thus enabling higher local drug concentration or extended therapy duration), as well as application of hydrophobic drugs that cannot be used in combination with existing TACE embolic particles.

Conventional Transarterial Chemo embolization Using Streptozocin in Patients with Unresectable Neuroendocrine Liver Metastases.

The purpose of this study was to evaluate the clinical, biological and radiological responses to, and tolerability of, conventional transarterial chemoembolization (cTACE) using streptozocin for unresectable neuroendocrine liver metastases. A total of 52 patients with predominant liver disease were treated with cTACE using an emulsion of streptozocin, Lipiodol and embolization particles. A sequential approach was favored in patients with high liver tumor burden. Clinical, biological and radiological responses were evaluated using carcinoid symptoms, biomarkers and mRecist criteria, respectively. A total of 127 procedures were performed with a sequential approach in 65% of patients. All patients received streptozocin and Lipiodol. Carcinoid syndrome was improved in 69% of patients after treatment (p = 0.01). Post-embolization syndrome was reported in 78% of patients. At the end of all cTACE, objective response and non-progressive disease were 32% and 70%, respectively. Progression-free survival was 18.3 ± 13.3 months (median 14.9) and median overall survival (OS) from start of treatment was 74 months. The OS at 1 year, 2 years, 3 years and 5 years was 91% (IC = 84-99%), 84% (CI = 72-95%), 69% (CI = 53-84%) and 63% (C = 46-81%), respectively. cTACE using streptozocin is an effective and well-tolerated palliative option for patients with neuroendocrine liver metastases, associated with prolonged survival and delayed time to progression.

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors.

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.