The discriminative role of PROX-1 immunohistochemistry between venous malformation and lymphatic malformation of the deep type with no visible diagnostic surface skin lesion.

BACKGROUND: Venous malformations (VMs) are distinguished from lymphatic malformations (LMs) when specific diagnostic skin lesions are present. In the deep type, this is difficult by clinico-radiologic evaluation alone. We aimed to investigate the usefulness of lymphatic vessel endothelial cell (LEC) markers for the differential diagnosis of the deep VMs and LMs. METHODS: A retrospective study was conducted based on the medical records of patients with VMs and LMs who underwent biopsy with both D2-40 and PROX-1 immunohistochemistry. We compared the initial clinico-radiological diagnosis with the final pathological diagnosis and identified which ones showed a difference. RESULTS: From 261 patients who had VMs and LMs, 111 remained after the exclusion of those who showed definite surface diagnostic features. After pathological diagnosis with the expressions of D2-40 and PROX-1, 38 of 111 (34.2%) patients' final diagnoses were changed. Among these 38 cases, diagnosis was not changed by D2-40 positivity alone, but changed by PROX-1 positivity alone (52.6%) or by both (47.4%). The diagnostic changes were more frequent in the deep category (43.7%) than in the superficial category. CONCLUSIONS: Identifying the expression of D2-40, and especially PROX-1, in the differential diagnosis of VMs and LMs may provide important treatment guidelines and understanding their natural course.

Factors Affecting Adverse Events after Venous Malformation Sclerotherapy.

PURPOSE: To evaluate factors that contribute to adverse events (AEs) after embolization of venous malformations (VMs) using sclerosing agents. MATERIALS AND METHODS: A retrospective review of patients who underwent direct puncture embolization of VMs with a sclerosing agent and adjunctive techniques, also termed as sclerotherapy, from 2016 to 2021 was performed. Three-hundred one embolizations in 137 patients (median age, 19.0 years; interquartile range, 12.8-31.5 years) were evaluated. The VM characteristics and embolization details were analyzed. Anticoagulation was also evaluated based on D-dimer levels. Cutaneous and noncutaneous AEs were analyzed. The AEs were categorized using Society of Interventional Radiology guidelines. RESULTS: VMs involving tissue planes were subcutaneous (n = 104), intramuscular (n = 84), and combined (n = 113). Overlying skin involvement was observed in 56% of the patients. Sodium tetradecyl sulfate was mainly used (83%). Periprocedural anticoagulation was used in 9% of the patients. Most AEs were minor (30/301, 9.7%), and only 1.7% (5/301) were major (21 cutaneous and 14 noncutaneous AEs). Age below 18 years (odds ratio, 4.4502; 95% confidence interval, 1.5607-12.6890; P = .0052) and overlying skin involvement (odds ratio, 7.1794; 95% confidence interval, 1.6226-31.7656; P = .0094) were factors associated with cutaneous AEs. All noncutaneous AEs developed in patients with intramuscular VMs; however, this association was not statistically significant. There was no severe hematologic AE or permanent consequence. CONCLUSIONS: The overall AE rate after VM embolization was 11.6%; however, major AEs were rare (1.7%). Cutaneous AEs were associated with young age and overlying skin involvement. All noncutaneous AEs developed in patients with intramuscular VMs.

Hypoxia Promotes Angiogenic Effect in Extracranial Arteriovenous Malformation Endothelial Cells.

Arteriovenous malformation (AVM) is characterized by high-flow blood vessels connecting arteries and veins without capillaries. This disease shows increased angiogenesis and a pathophysiological hypoxic environment in proximal tissues. Here, we analyzed the effects of hypoxia on angiogenesis in the endothelial cells (ECs) of AVM and normal tissues. ECs from human normal and AVM tissues were evaluated using immunocytochemistry with CD31. In vitro tube formation under hypoxia was tested in both ECs using Matrigel. The relative expression of angiogenesis-related genes was measured using real-time PCR. Under normoxia, CD31 was significantly higher in AVM ECs (79.23 ± 0.65%) than in normal ECs (74.15 ± 0.70%). Similar results were observed under hypoxia in AVM ECs (63.85 ± 1.84%) and normal ECs (60.52 ± 0.51%). In the tube formation test under normoxic and hypoxic conditions, the junction count and total vessel length were significantly greater in AVM ECs than normal ECs. Under both normoxia and hypoxia, the angiogenesis-related gene FSTL1 showed a significantly higher expression in AVM ECs than in normal ECs. Under hypoxia, CSPG4 expression was significantly lower in AVM ECs than in normal ECs. Accordingly, the angiogenic effect was increased in AVM ECs compared with that in normal ECs. These results provide a basic knowledge for an AVM treatment strategy.

Oscillatory shear stress promotes angiogenic effects in arteriovenous malformations endothelial cells.

BACKGROUND: Vascular endothelial cells (ECs) are subject to continuous shear stress due to blood circulation. Mechanical stress due to high shear flow can also cause arteriovenous malformation (AVM) when ECs respond hyper-sensitively to shear flow. This study was conducted to test the hypothesis that angiogenesis could be promoted in response to mechanical stress via regulation of pro-angiogenic factors in AVM cells. METHODS: ECs were extracted from the tissue samples from six AVM patients and six normal patients. Shear stress at 7 dynes/cm2 were applied for 24 h. Before and after application of shear stress to each group, RT-PCR was performed to access the expression levels of angiopoietin2(AGP2), aquaporin1(AQP1) and TGFßR1. Immunofluorescences was also performed to evaluate the level of protein expressions. RESULTS: In both normal and AVM tissues, AGP2 and TGFßR1 under the shear stress showed increased expression in the ECs compared to the non-sheared samples. When AVMs and normal arterial vasculature were compared, the expression levels of both AGP2 and TGFßR1 in AVMs were higher when compared to normal arterial vasculature with or without shear stress. Immunofluorescence-based protein analysis also confirmed shear-induced AGP2 and TGFßR1 in both samples of normal and AVM patients. CONCLUSIONS: AVMs exhibited higher sensitivity to shear stress by producing higher expressions of some marked genes and proteins that regulate the endothelial functions upon exposure to shear stress. While the physiological mechanism for AVMs remain elusive, our study shows the plausibility of physical stress imposed by the shearing flow can cause the occurrence of AVMs.

Efficacy and Safety of Transvenous Embolization of Type II Renal Arteriovenous Malformations with Coils.

PURPOSE: To evaluate the efficacy and safety of transvenous coil embolization of the venous sac for type II renal arteriovenous malformation (AVM). MATERIALS AND METHODS: A retrospective review was conducted of 8 patients (5 women and 3 men; mean age, 57 years; age range, 41-69 years) who underwent transvenous coil embolization for type II congenital renal AVM at 5 different hospitals between 2012 and 2018. Additional intra-arterial ethanol injection was performed if shunt flow persisted after venous sac coiling. Technical success was defined as complete occlusion of shunt flow with coil embolization. Clinical success was defined as no symptom recurrence during the follow-up period. The renal parenchymal infarction rate was measured on computed tomography (CT), and procedure-related complications were reviewed. RESULTS: Nine sessions of embolization were performed for 8 patients. The mean venous sac size was 24 mm (range, 10-39 mm), and a mean of 14 micro and/or micro-detachable coils (range, 3-50) were used. The technical success rate was 88% (7 of 8) using coil embolization. One patient (12%) required additional ethanol injection to complete occlusion of the shunt flow and had a less than 10% parenchymal infarction on follow-up CT. No procedure-related complications or recurrences occurred during a mean clinical follow-up period of 20.8 months (range, 4.7-76.6 months). CONCLUSIONS: Transvenous coil embolization of type II renal AVM showed an 88% technical success rate. One patient (12%) showed less than 10% renal parenchymal infarction after additional ethanol injection. No additional complications or recurrences occurred during the follow-up period.

Efficacy and Safety of AMPLATZER Vascular Plug Type IV for Embolization of Pulmonary Arteriovenous Malformations.

PURPOSE: To assess the efficacy and safety of the AMPLATZER Vascular Plug type IV for pulmonary arteriovenous malformation (PAVM) treatment. MATERIALS AND METHODS: Between June 2013 and January 2018, 13 patients with 26 PAVMs were treated with the type IV AVP. Patients without follow-up computed tomography (CT) were excluded. Technical success was defined as flow occlusion on angiography. Plug-to-sac distance was measured on angiographic images. Feeding artery and venous sac diameter changes were measured on preprocedural and follow-up CT. Successful embolization was defined as > 70% sac size regression. Procedure time, device migration, and complications were evaluated. RESULTS: Nine female patients (mean age, 49 y; range, 40-71 y) with 19 PAVMs were enrolled. Four patients with 7 PAVMs were lost to follow-up. Nineteen PAVMs were treated in 11 sessions, and the mean procedure time was 29 min. The technical success rate was 100%. Mean feeding artery diameter was 3.1 mm ± 0.7 (range, 2.1-4.9 mm). Mean plug-to-sac distance was 5.4 mm ± 4.9 (range, 0-13.3 mm). The mean CT follow-up period was 14 months ± 7 (range, 6-30 mo). Sixteen of 19 PAVMs (84%) were successfully embolized. Minor complications (tachycardia and chest discomfort) arose in 2 of 11 sessions. No device migrations or major complications occurred. CONCLUSIONS: The type IV AVP showed an 84% treatment success rate based on 70% sac size regression criteria in small PAVMs. There were no device migrations or major complications.

Effect of Hyperbilirubinemia on Hepatic Hypertrophy after Portal Vein Embolization and Liver Failure after Hepatectomy in Primary Biliary Malignancy.

PURPOSE: To retrospectively investigate the impact of hyperbilirubinemia on future liver remnant (FLR) volume after percutaneous transhepatic portal vein embolization (PVE) and incidence of post-hepatectomy liver failure in primary biliary malignancy. MATERIALS AND METHODS: Eighty-seven patients (62 men, overall mean age 66.9 y) who underwent PVE, using Gelfoam and coils before major hepatectomy between January 2004 and June 2016, were included in this study and divided into a hyperbilirubinemia (serum total bilirubin level at PVE 5.80 ± 2.44 mg/dL; n = 41) group and a control group (1.09 ± 0.73 mg/dL; n = 46). Liver volume was measured from computerized tomographic data before and 18.5 days, on average, after PVE. Correlation between FLR hypertrophy (degree of hypertrophy and percentage increase in future liver remnant [%FLR]) and total bilirubin were analyzed. FLR hypertrophy and incidence of post-hepatectomy liver failure were compared. Simple and multiple regressions were used for univariable and multivariable analyses, respectively. RESULTS: Mean FLR volumes before and after PVE were 529.1 cm3 and 640.5 cm3, respectively. Degree of hypertrophy and %FLR were 7.64 ± 4.22 and 21.77 ± 13.34, respectively. There was no significant correlation between FLR hypertrophy and total bilirubin (P > .5). FLR hypertrophy was not significantly different between the 2 groups. Planned major hepatectomy was performed in 73 patients (83.9%). Grade 3 post-hepatectomy liver failure occurred in 6 patients (8.2%; 2 in the hyperbilirubinemia group and 4 in the control group), and its incidence was not significantly different between the groups (P = .354). CONCLUSIONS: Hyperbilirubinemia at the time of PVE seems to have no effect on FLR hypertrophy. The incidence of grade 3 post-hepatectomy liver failure is not likely to be influenced, either.

Iterative Metallic Artifact Reduction for In-Plane Gonadal Shielding During Computed Tomographic Venography of Young Males.

OBJECTIVE: The purpose of this study was to evaluate a gonadal shield (GS) and iterative metallic artifact reduction (IMAR) during computed tomography scans, regarding the image quality and radiation dose. METHODS: A phantom was imaged with and without a GS. Prospectively enrolled, young male patients underwent lower extremity computed tomography venography (precontrast imaging without the GS and postcontrast imaging with the GS). Radiation dose was measured each time, and the GS-applied images were reconstructed by weighted filtered back projection and IMAR. RESULTS: In the phantom study, image artifacts were significantly reduced by using IMAR (P = 0.031), whereas the GS reduced the radiation dose by 61.3%. In the clinical study (n = 29), IMAR mitigated artifacts from the GS, thus 96.6% of the IMAR image sets were clinically usable. Gonadal shielding reduced the radiation dose to the testes by 69.0%. CONCLUSIONS: The GS in conjunction with IMAR significantly reduced the radiation dose to the testes while maintaining the image quality.

Combined transarterial chemoembolization and radiofrequency ablation for small treatment-naïve hepatocellular carcinoma infeasible for ultrasound-guided radiofrequency ablation: long-term outcomes.

Background Ultrasound (US)-guided radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC) is often infeasible due to unfavorable location and poor conspicuity. Those small HCCs can be treated with combined transarterial chemoembolization (TACE) and RFA. Purpose To evaluate long-term outcomes of combined TACE and RFA for small treatment-naïve HCC infeasible for US-guided RFA. Material and Methods Between February 2009 and January 2014, 69 patients with small (≤3 cm) HCC infeasible for US-guided RFA received TACE and subsequent RFA in one session as a first-line treatment. Local tumor progression (LTP), overall survival (OS), and event-free survival rates were evaluated. Univariate and multivariate analyses were conducted to identify prognostic factors. Results Cumulative rates of LTP were 4.4%, 6.8%, 8.2%, 9.5%, and 9.5% at one, two, three, five, and seven years, respectively. Cumulative one-, two-, three-, five-, and seven-year OS rates were 100%, 95%, 89%, 80%, and 80%, respectively. Cumulative one-, two-, three-, five-, and seven-year event-free survival rates were 81%, 63%, 54%, 31%, and 20%, respectively. No significant prognostic factors for LTP, OS, and event-free survival were identified in univariate analysis. Conclusion Combined TACE and RFA appears to be an effective treatment for small treatment-naïve HCC infeasible for US-guided RFA in terms of LTP and OS.

Various factors contribute to graft extrusion in lateral meniscus allograft transplantation.

PURPOSE: Lateral meniscus allograft transplantation (LMAT) is a feasible surgical option for young meniscus-deficient patients. Although several studies have explored the factors that contribute to graft extrusion, they have not been fully elucidated. The aim of this study was to determine the various factors that contribute to graft extrusion. METHODS: Patients with knees that had received LMAT using a keyhole technique (n = 87 knees in 82 patients) were reviewed. The median age of these patients was 22 years (range 19-54 years), and the median postprocedural follow-up interval was 5 days (range 1-136 days). Twelve magnetic resonance imaging (MRI) measurement parameters (axial and coronal location of the bone block) that could potentially influence graft extrusion were evaluated, along with absolute graft extrusion and relative percentage of extrusion (RPE). RESULTS: A significant correlation was found between 8 of the 12 MRI measurement parameters and both the absolute extrusion and RPE (r = 0.241-0.438, p < 0.05). The absolute middle distance and depth of the bone block were independent predictors of the absolute extrusion (ß = 0.30 and 0.15, respectively; p < 0.05), and the relative middle distance and relative bone-block elevation were found to be predictors of RPE (ß = 2.29 and 1.44, respectively; p < 0.05). CONCLUSION: The rate of graft extrusions after LMAT was high in this study. Both the coronal and axial locations of the bone block were found to influence graft extrusion in LMAT. Therefore, correct positioning of the bone block, including in both the axial and coronal planes, is essential to minimize graft extrusion. Future studies need to investigate the long-term clinical outcome and longevity of extruded menisci after transplantation. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.

Sociodemographic characteristics of pediatric patients with vascular malformations: Results of a single site study.

Vascular malformations, the abnormal development of blood vessels, are a rare set of congenital anomalies. The sociodemographic factors associated with vascular malformations in pediatric patients are poorly understood. This study examined sociodemographic factors of 352 patients presenting to a single vascular anomaly center from July 2019 to September 2022. Characteristics such as race, ethnicity, sex, age at presentation, degree of urbanization, and insurance status were recorded. This data was analyzed by comparing the different types of vascular malformations, including arteriovenous malformation, capillary malformation, venous malformation (VM), lymphatic malformation (LM), lymphedema, and overgrowth syndrome. Patients were primarily white, not Hispanic or Latino, female, had private health insurance, and were from the most urban setting. No differences in sociodemographic factors were found among the different vascular malformations except patients with VM presented at a later age than patients with LM or overgrowth syndrome. This study provides novel insight into the sociodemographic factors of pediatric patients presenting with vascular malformations and indicates a need for their improved recognition for the timely initiation of treatment.

Efficacy and safety of transarterial bleomycin sclerotherapy of early-stage facial arteriovenous malformation: Single-center multidisciplinary team experience.

BACKGROUND: To evaluate the efficacy and safety of transarterial bleomycin sclerotherapy of early-stage facial arteriovenous malformation (AVM). METHODS: A retrospective review was performed of patients who underwent bleomycin sclerotherapy for early-stage AVM (Schobinger stage I or II) in a single-referral vascular anomalies center. Bleomycin was slowly infused transarterially with flow control techniques to prolong the effects of bleomycin. Procedure details, AVM characteristics, and previous treatments were reviewed. Initial therapeutic outcomes were determined by 5 categories using both radiological and clinical findings in a 6-month follow-up. Further follow-up outcomes were reviewed to evaluate the long-term efficacy and safety of the treatment. Procedure-related complications were also analyzed. RESULTS: Nineteen patients (mean age 22.4 ± 14.0 years, 14 females) with 31 sessions of sclerotherapies were enrolled. All AVMs were Cho-Do classification type III (type IIIa [n = 13], type IIIb [n = 2], and type IIIa+b [n = 4]). Patients received a mean of 1.6 (range, 1-4) sessions of treatment. The mean cumulative bleomycin dose was 23,600 IU ± 14,500 (range, 8000 - 60,000 IU). The results showed that 14 patients (74%) were responsive to transarterial bleomycin sclerotherapy, including complete response (n = 3), marked improvement (n = 1), and partial improvement (n = 10). The remaining 5 (26%) showed no response. During a mean follow-up of 32.6 months, 5 (26%) showed slight progression compared with 6-month outcomes and 14 (74%) were stable. There were only 2 minor complications [hyperpigmentation (n = 1) and cellulitis (n = 1)]. CONCLUSIONS: Transarterial bleomycin sclerotherapy using flow control techniques can be a safe and feasible alternative treatment option for facial early-stage AVM.

CT evaluation of systemic artery to pulmonary artery fistula: an underdiagnosed disease in patients with hemoptysis.

Background: Systemic artery to pulmonary artery fistula (SA-PAF) is an uncommon disease which is often incidentally diagnosed during evaluation of hemoptysis patients. The aim of our study was to describe the cases of SA-PAF in our institution and to report the correlating clinical and radiological findings. Methods: We reviewed 231 chest computed tomography (CT) scans performed in our institution due to hemoptysis from January 2020 to February 2023. In patients diagnosed with SA-PAF had their electronic medical records and CT images analyzed. Results: In 231 patients, 19 (8.2%) of them had SA-PAF findings which was characterized by a peripheral nodular soft tissue opacity in the subpleural lung and traceable vascular structure in continuity with one or more peripheral pulmonary artery branches in CT. Etiology of each patient was categorized as either congenital (7, 36.8%), and acquired (12, 63.2%). The origins of SA-PAFs were 16 intercostal, two anterior mediastinal, and one costocervical artery. Eight of 19 patients did not show any associated intralobar imaging abnormalities, while bronchiectasis, cellular bronchiolitis, centrilobular emphysema, and pleura effusion were observed in 11 patients. Conclusions: SA-PAF is a benign vascular anomaly which is frequently overlooked when evaluating hemoptysis by either clinician or radiologists but is an important factor in the differential diagnosis of patients with hemoptysis.

Endovascular Treatment of Incidentally Found Multiple Aneurysms Originating from a Bronchial Artery: A Case Report.

Bronchial artery aneurysm (BAA) is a rare disease, and multiple aneurysms of a single bronchial artery are rarer. Regardless of the size of the lesion, it is at risk of rupture and can cause massive hemoptysis or severe pain. We report a rare case of bronchial artery embolization (BAE) of multiple aneurysms of a single bronchial artery. During medical examination, a 64-year-old female was diagnosed with multiple BAAs and endobronchial lesions in the right lower lung on CT 10 years prior to presentation to our hospital. Further evaluation of the lesions was recommended; however, the patient was lost to follow-up. The patient complained of dyspnea and visited our hospital, and the size of the BAA had increased on CT. BAE was done successfully using N-butyl-2-cyanoacrylate and detachable coils. Follow up CT after BAE showed significant decrease in extent of inflammatory lesion in the right lung.

Iatrogenic pulmonary artery perforation associated with 5-Fr catheter manipulation during pulmonary arteriovenous malformation embolization with a vascular plug.

Vascular plugs have been increasingly used because they have lower recanalization rates than coil embolization in pulmonary arteriovenous malformation (PAVM) embolization. To deliver the vascular plug close to the PAVM, a large-diameter catheter should be advanced into the feeding pulmonary artery, which carries a risk of vascular damage. Fifty-three-year-old women was admitted to our hospital for embolization of a single PAVM. Pulmonary angiography revealed a simple PAVM with a tortuous, small feeding artery in the right middle lobe, and feeding artery negotiation was attempted using a 5-Fr headhunter-type catheter to deliver the vascular plug. However, unintentional arterial perforation occurred suddenly when the guide wire was withdrawn after the catheter was advanced to the feeding artery adjacent to the sac. Immediate embolization using a vascular plug and microcoils at the proximal site of the perforation was performed to stop both PAVM shunt flow and bleeding. To prevent such a catheter-induced complication, it is necessary to select a diagnostic catheter with appropriate stiffness and angle and to switch to a small-diameter delivery system depending on the situation.

Traumatic iliac vein rupture managed using a bare-metal stent.

Iliac vein rupture resulting from blunt trauma is rare but can be fatal and challenging to diagnose despite thorough clinical investigation and image workup. Here, we present a case of traumatic iliac vein rupture managed by emergent endovascular repair using a bare-metal stent. Low pressure traumatic venous rupture is different from arterial rupture, and a bare-metal stent can be a sufficient tool to control bleeding.

Evaluating oxygen shielding effect using glycerin or vacuum with varying temperature on 3D printed photopolymer in post-polymerization.

The photosensitive resin used in additive manufacturing is cured by free radical polymerization by UV irradiation. However, undesired reaction with oxygen during polymerization inhibits polymerization and results in an under-cured polymer. Therefore, in this study, the hypothesis that successful oxygen shielding in the post-polymerization step could affect the properties of the final polymer was tested. 3D printed specimens using denture base resin were post polymerized either by immersion in glycerin for oxygen shielding (GL group) or placed in a medium-low vacuum chamber at 5 × 10-2 Torr (VA group). Specimens cured with no additional conditioning served as the control (CON group). To consider the effect of temperature, all groups were additionally compared with 80 °C and without an increase in temperature (room temperature) during post-polymerization. Fourier transform infrared spectroscopy was used to measure the monomer conversion ratios between different groups. In addition, the mechanical properties were quantified by the micro-hardness, flexural strength, and elasticity of the surface, and the water sorption and solubility. Dynamic mechanical analysis (DMA) was conducted to observe the trend in storage and loss modulus between the groups against temperature. Differences in the surface as a function of the post-polymerization conditions were qualitatively observed by scanning electron microscopy (SEM). The result shows that oxygen shielding during post-polymerization showed an increase in the degree of conversion (DC) and hardness of the resin surface. The highest DC was observed for GL group specimens at both room temperature and 80 °C. This result was confirmed by the SEM micrographs of the resin surface, where the interface between the layers of the GL group structure becomes more robust. However, a difference was observed between the samples prepared at room temperature and 80 °C. The flexural modulus was highest in the GL group, followed by the VA group, and lowest in the CON group at 80 °C. No difference in water absorption was observed for any groups, but high water solubility was observed in the GL group at room temperature. Overall, more significant differences in the properties were observed for the samples post-polymerized at 80 °C than at room temperature. The results of DMA analysis to determine the glass transition temperature showed a similar trend in all groups, and the storage modulus and loss rate obtained in the same experiment decreased in the order of GL, CON, and VA. In conclusion, an oxygen shielded post-polymerization environment at elevated temperature effectively improves the mechanical properties of photosensitive resin.