Imaging-Guided Metabolic Radiosensitization of Pediatric Rhabdoid Tumors.

Tumor hypoxia leads to increased resistance to radiation therapy (RT), resulting in markedly worse clinical outcomes in the treatment and management of pediatric malignant rhabdoid tumors (MRT). To alleviate hypoxia in MRT, we repurposed an FDA approved, mitochondrial oxidative phosphorylation (OXPHOS) inhibitor, Atovaquone (AVO), to inhibit oxygen consumption and thereby enhance the sensitivity of tumor cells to low dose RT in MRT by hypoxia alleviation. Additionally, to better understand the tumor response induced by AVO and optimize the combination with RT, we employed an emerging, noninvasive imaging modality, known as multispectral optoacoustic tomography (MSOT), to monitor and evaluate real-time dynamic changes in tumor hypoxia and vascular perfusion. Oxygen-Enhanced (OE)-MSOT could measure the change of tumor oxygenation in the MRT xenograft models after AVO and RT treatments, indicating its potential as a response biomarker. OE-MSOT showed that treating MRT mouse models with AVO resulted in a transient increase in oxygen saturation (ΔsO 2 ) in tumors when the mice were subjected to oxygen challenge, while RT or saline treated groups produced no change. In AVO+RT combination groups, the tumors showed an increase in ΔsO 2 after AVO administration followed by a significant decrease after RT, that correlated with a strong anti-tumor response, demarcated by complete regression of tumors, with no relapse on long-term monitoring. These observations were histologically validated. In MRT models of acquired AVO resistance, combination therapy failed to alleviate tumoral hypoxia and elicit any therapeutic benefit. Together, our data highlights the utility of repurposing anti-malarial AVO as an anticancer adjuvant for enabling low dose RT for pediatric patients.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months.

OBJECTIVE: To determine the safety and effectiveness of vena cava filters (VCFs). METHODS: A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed. RESULTS: VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement. CONCLUSIONS: Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months.

OBJECTIVE: To determine the safety and effectiveness of vena cava filters (VCFs). METHODS: A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed. RESULTS: VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement. CONCLUSIONS: Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Society of interventional radiology clinical practice guideline for inferior vena cava filters in the treatment of patients with venous thromboembolic disease

To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease. A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations. The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations. Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population.

Society of Interventional Radiology Clinical Practice Guideline for Inferior Vena Cava Filters in the Treatment of Patients with Venous Thromboembolic Disease: Developed in collaboration with the American College of Cardiology, American College of Chest Physicians, American College of Surgeons Committee on Trauma, American Heart Association, Society for Vascular Surgery, and Society for Vascular Medicine.

PURPOSE: To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease. MATERIALS AND METHODS: A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations. RESULTS: The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations. CONCLUSIONS: Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population.

Extracellular glutamate and IDH1R132H inhibitor promote glioma growth by boosting redox potential.

PURPOSE: Somatic mutations of the isocitrate dehydrogenase 1 (IDH1) gene, mostly substituting Arg132 with histidine, are associated with better patient survival, but glioma recurrence and progression are nearly inevitable, resulting in disproportionate morbidity and mortality. Our previous studies demonstrated that in contrast to hemizygous IDH1R132H (loss of wild-type allele), heterozygous IDH1R132H is intrinsically glioma suppressive but its suppression of three-dimensional (3D) growth is negated by extracellular glutamate and reducing equivalent. This study sought to understand the importance of 3D culture in IDH1R132H biology and the underlying mechanism of the glutamate effect. METHODS: RNA sequencing data of IDH1R132H-heterozygous and IDH1R132H-hemizygous glioma cells cultured under two-dimensional (2D) and 3D conditions were subjected to unsupervised hierarchal clustering and gene set enrichment analysis. IDH1R132H-heterozygous and IDH1R132H-hemizygous tumor growth were compared in subcutaneous and intracranial transplantations. Short-hairpin RNA against glutamate dehydrogenase 2 gene (GLUD2) expression was employed to determine the effects of glutamate and the mutant IDH1 inhibitor AGI-5198 on redox potential in IDH1R132H-heterozygous cells. RESULTS: In contrast to IDH1R132H-heterozygous cells, 3D-cultured but not 2D-cultured IDH1R132H-hemizygous cells were clustered with more malignant gliomas, possessed the glioblastoma mesenchymal signature, and exhibited aggressive tumor growth. Although both extracellular glutamate and AGI-5198 stimulated redox potential for 3D growth of IDH1R132H-heterozygous cells, GLUD2 expression was required for glutamate, but not AGI-5198, stimulation. CONCLUSION: 3D culture is more relevant to IDH1R132H glioma biology. The importance of redox homeostasis in IDH1R132H glioma suggests that metabolic pathway(s) can be explored for therapeutic targeting, whereas IDH1R132H inhibitors may have counterproductive consequences in patient treatment.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters Study: Design of a unique safety and effectiveness study of inferior vena cava filters in clinical practice.

BACKGROUND: Death from venous thromboembolism remains a significant cause of death worldwide. Although anticoagulation is the cornerstone of treatment in patients at risk for venous thromboembolism, inferior vena cava (IVC) filter use has increased exponentially over the last decade driven predominantly by the prophylactic use in patients at risk for venous thromboembolism despite limited evidence supporting this practice. The Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE) Study is being implemented by the Society for Vascular Surgery, Society of Interventional Radiology, U.S. Food and Drug Administration, and several IVC filter manufactures to better understand the safety, effectiveness, and current patterns of real-world use of IVC filters. METHODS: The PRESERVE Study includes IVC filters from seven manufacturers: ALN (ALN ± hook), Argon (Option Elite), B. Braun (LP, Vena Tech Convertible), CR Bard (Denali), Cook (Gunther Tulip), Cordis (OptEase, TrapEase), and Philips Volcano (Crux). The indications for filter placement, filter brand, complications, stability, frequency and success of retrieval, and clinical effectiveness of each filter will be recorded. Approximately 2100 patients (300 for each filter brand included in the study) are intended to be enrolled at 60 U.S. centers. RESULTS: Men and women age 18 years or older requiring IVC filters for prevention of venous thromboembolism will be included in the study if no contrast allergy is present and they are willing to commit to the prescribed study follow-up. Participants will be evaluated at discharge, 3, 6, 12, 18, and 24 months after filter placement and/or 1 month after retrieval, which ever occurs first. Intravascular ultrasound examination or venography will be done before and after IVC filter placement, with abdominal plain film at 3 months, and contrast enhanced computed tomography scans at 12 and 24 months to evaluate filter stability. The primary safety end point is a composite of clinical end points, including freedom from perforation, embolization, thrombosis, recurrent DVT, and defined serious adverse events. Secondary end points include mechanical stability and procedure related complications at 3 months, major adverse events at 6, 12, 18, and 24 months, and filter tilt of more than 15° at any point. CONCLUSIONS: The PRESERVE Study represents the largest prospective study ever undertaken to investigate real-world outcomes with contemporary use of IVC filters. The investigators await results with the hope that it can improve patient care.

Long-term complications of inferior vena cava filters.

Anticoagulation is the cornerstone for the treatment of deep venous thrombosis and pulmonary embolism. On occasion, this is not possible because of bleeding complications or, rarely, breakthrough pulmonary embolism associated with this treatment method. The development of vena cava interruption in the 1970s was a critical advance in the treatment of these patients. Placement of inferior vena cava (IVC) filters has been steadily increasing since their introduction. Nonetheless, the incidence of complications associated with placement of these devices is largely unknown. Most of the evidence regarding IVC filter complications relies on case reports, with scarce data coming from larger randomized controlled trials. We aimed to present a summary addressing long-term complications of IVC filters as published in recent articles addressing problems such as IVC thrombosis and IVC filter migration, perforation, fracture, embolization, and tilting. We performed a PubMed search and Google Scholar search using different combinations of "long term," "complications," "IVC filter," and "vena cava filter." We reviewed the available English publications and reported the findings in this summary.

IDH1R132H is intrinsically tumor-suppressive but functionally attenuated by the glutamate-rich cerebral environment.

Recurrent heterozygous mutation of isocitrate dehydrogenase 1 gene (IDH1), predominantly resulting in histidine substitution at arginine 132, was first identified in glioma. The biological significance of IDH1R132H, however, has been controversial, and its prevalent association with glioma remains enigmatic. Although recent studies indicate that IDH1R132H is nonessential to tumor growth or even anti-tumor growth, whether IDH1R132H initiates gliomagenesis remains obscure. In this study, we report that IDH1R132H is intrinsically tumor-suppressive but the activity can be attenuated by glutamate-the cerebral neurotransmitter. We observed that IDH1R132H was highly suppressive of subcutaneous tumor growth driven by platelet-derived growth factor B (PDGFB), but IDH1R132H tumor growth and glioma penetrance were virtually indistinguishable from those of IDH1-wildtype tumors in orthotopic models. In vitro, addition of glutamate compromised IDH1R132H inhibition of neurosphere genesis, indicating glutamate promotion of oncogenic dominance. Furthermore, we observed that IDH1R132H expression was markedly decreased in tumors but became more permissible upon the deletion of tumor-suppressor gene Cdkn2a. To provide direct evidence for the opposing effect of IDH1R132H on PDGFB-driven glioma development, we explored tandem expression of the two molecules from a single transcript to preclude selection against IDH1R132H expression. Our results demonstrate that when juxtaposed with oncogenic PDGFB, IDH1R132H overrides the oncogenic activity and obliterates neurosphere genesis and gliomagenesis even in the glutamate-rich microenvironment. We propose therefore that IDH1R132H is intrinsically suppressive of glioma initiation and growth but such tumor-suppressive activity is compromised by the glutamate-rich cerebral cortex, thereby offering a unifying hypothesis for the perplexing role of IDH1R132H in glioma initiation and growth.

Correlation of Glioma Proliferation and Hypoxia by Luciferase, Magnetic Resonance, and Positron Emission Tomography Imaging.

Gliomas are the most common type of primary, malignant brain tumor and significantly impact patients, who have a median survival of ~1 year depending on mutational background. Novel imaging modalities such as luciferase bioluminescence, micro-magnetic resonance imaging (micro-MRI), micro-computerized tomography (micro-CT), and micro-positron emission tomography (micro-PET) have expanded the portfolio of tools available to study this disease. Hypoxia, a key oncogenic driver of glioma and mechanism of resistance, can be studied in vivo by the concomitant use of noninvasive MRI and PET imaging. We present a protocol involving stereotactic injection of syngenic F98 luciferase-expressing glioma cells generated by our laboratory into Fischer 344 rat brains and imaging using luciferase. In addition, 18-F-fludeoxyglucose, 18F-fluoromisonidazole, and 18F-fluorothymidine PET imaging are compared with quantified luciferase flux. These tools can potentially be used for assessing tumor growth characteristics, hypoxia, mutational effects, and treatment effects.

Combined Hydroxyurea and Verapamil in the Clinical Treatment of Refractory Meningioma: Human and Orthotopic Xenograft Studies.

OBJECTIVE: Previous in vitro and in vivo results suggested that hydroxyurea (HU) and verapamil could suppress meningioma growth individually and synergistically. We evaluated the clinical efficacy and safety of this approach for the treatment of refractory recurrent/progressive meningiomas and expanded our studies in a xenograft orthotopic mouse model. METHODS: Six women and 1 man, aged 26-76 years (median, 56 years), with magnetic resonance imaging-proven progression of ≥ 25% in cross-sectional area of recurrent meningioma (2 World Health Organization grade I, 5 grade II) within the preceding 6 months received HU 1000 or 1500 mg/day (20 mg/kg/day, twice daily) as well as verapamil sustained-release tablets with dose escalation every 2 weeks (120-240 mg/day). They underwent magnetic resonance imaging every 3 months during therapy. To augment the clinical trial results, we performed mouse orthotopic xenograft experiments using similar dosing to test tumor growth, vascularity, and drug bioavailability. RESULTS: After a mean of 8.1 cycles of treatment, the patients demonstrated no significant radiographic responses during mean follow-up of 14.5 ± 4.8 months. Median progression-free survival (PFS) was 8.0 months, and 6-month PFS was 85%. Side effects occurred in 6 (86%) patients. Xenograft studies showed no effect of individual or combined treatments on meningioma growth. Neither HU nor verapamil was detectable in mouse brain tumor tissue despite adequate serum levels within therapeutic ranges. CONCLUSIONS: Our results showed no effect of HU or verapamil on tumor recurrence, PFS, and in vivo tumor burden reduction. Drug delivery to the tumor may be a major limitation.

Contemporary results of carotid endarterectomy in "normal-risk" patients from the Society for Vascular Surgery Vascular Registry.

OBJECTIVE: Acceptable complication rates after carotid endarterectomy (CEA) are drawn from decades-old data. The recent Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) demonstrated improved stroke and mortality outcomes after CEA compared with carotid artery stenting, with 30-day periprocedural CEA stroke rates of 3.2% and 1.4% for symptomatic (SX) and asymptomatic (ASX) patients, respectively. It is unclear whether these target rates can be attained in "normal-risk" (NR) patients experienced outside of the trial. This study was done to determine the contemporary results of CEA from a broader selection of NR patients. METHODS: The Society for Vascular Surgery (SVS) Vascular Registry was examined to determine in-hospital and 30-day event rates for NR, SX, and ASX patients undergoing CEA. NR was defined as patients without anatomic or physiologic risk factors as defined by SVS Carotid Practice Guidelines. Raw data and risk-adjusted rates of death, stroke, and myocardial infarction (MI) were compared between the ASX and SX cohorts. RESULTS: There were 3977 patients (1456 SX, 2521 ASX) available for comparison. The SX group consisted of more men (61.7% vs 57.0%; P = .0045) but reflected a lower proportion of white patients (91.3% vs 94.4%; P = .0002), with lower prevalence of coronary artery disease (P < .0001), prior MI (P < .0001), peripheral vascular disease (P = .0017), and hypertension (P = .029), although New York Heart Association grade >3 congestive heart failure was equally present in both groups (P = .30). Baseline stenosis >80% on duplex imaging was less prevalent among SX patients (54.2% vs 67.8%; P < .0001). Perioperative stroke rates were higher for SX patients in the hospital (2.8% vs 0.8%; P < .0001) and at 30 days (3.4% vs 1.0%; P < .0001), which contributed to the higher composite death, stroke, and MI rates in the hospital (3.6% vs 1.8; P = .0003) and at 30 days (4.5% vs 2.2%; P < .0001) observed in SX patients. After risk adjustment, the rate of stroke/death was greater among SX patients in the hospital (odds ratio, 2.05; 95% confidence interval, 1.18-3.58) although not at 30 days (odds ratio, 1.36; 95% confidence interval, 0.85-2.17). No in-hospital or 30-day differences were observed for death or MI by symptom status. CONCLUSIONS: The SVS Vascular Registry results for CEA in NR patients are similar by symptom status to those reported for CREST and may serve as a benchmark for comparing results of alternative therapies for treatment of carotid stenosis in NR patients outside of monitored clinical trials. The contemporary perioperative risk of stroke after CEA in NR patients continues to be higher for SX than for ASX patients.

Intermittent induction of HIF-1α produces lasting effects on malignant progression independent of its continued expression.

Dysregulation of hypoxia-inducible transcription factors HIF-1α and HIF-2α correlates with poor prognosis in human cancers; yet, divergent and sometimes opposing activities of these factors in cancer biology have been observed. Adding to this complexity is that HIF-1α apparently possesses tumor-suppressing activities, as indicated by the loss-of-function mutations or even homozygous deletion of HIF1A in certain human cancers. As a step towards understanding this complexity, we employed 8-week intermittent induction of a stable HIF-1α variant, HIF1α(PP), in various cancer cell lines and examined the effects on malignant progression in xenografts of immunocompromised mice in comparison to those of HIF2α(PP). Although 8-week treatment led to eventual loss of HIF1α(PP) expression, treated osteosarcoma U-2 OS cells acquired tumorigenicity in the subcutaneous tissue. Furthermore, the prior treatment resulted in widespread invasion of malignant glioma U-87 MG cells in the mouse brain and sustained growth of U-118 MG glioma cells. The lasting effects of HIF-1α on malignant progression are specific because neither HIF2α(PP) nor ß-galactosidase yielded similar effects. By contrast, transient expression of HIF1α(PP) in U-87 MG cells or constitutive expression of HIF1α(PP) but not HIF2α(PP) in a patient-derived glioma sphere culture inhibited tumor growth and spread. Our results indicate that intermittent induction of HIF-1α produces lasting effects on malignant progression even at its own expense.

OKN-007 decreases tumor necrosis and tumor cell proliferation and increases apoptosis in a preclinical F98 rat glioma model.

BACKGROUND: Glioblastoma is a malignant World Health Organization (WHO) grade IV glioma with a poor prognosis in humans. New therapeutics are desperately required. The nitrone OKN-007 (2,4-disulfophenyl-PBN) has demonstrated effective anti-glioma properties in several rodent models and is currently being used as a clinical investigational drug for recurrent gliomas. We assessed the regional effects of OKN-007 in the tumor necrotic core and non-necrotic tumor parenchyma. METHODS: An F98 rat glioma model was evaluated using proton magnetic resonance spectroscopy ((1) H-MRS), diffusion-weighted imaging (DWI), morphological T2-weighted imaging (T2W) at 7 Tesla (30 cm-bore MRI), as well as immunohistochemistry and microarray assessments, at maximum tumor volumes (15-23 days following cell implantation in untreated (UT) tumors, and 18-35 days in OKN-007-treated tumors). RESULTS: (1) H-MRS data indicates that Lip0.9/Cho, Lip0.9/Cr, Lip1.3/Cho, and Lip1.3/Cr ratios are significantly decreased (all P < 0.05) in the OKN-007-treated group compared with UT F98 gliomas. The Cho/Cr ratio is also significantly decreased in the OKN-007-treated group compared with UT gliomas. In addition, the OKN-007-treated group demonstrates significantly lower ADC values in the necrotic tumor core and the nonnecrotic tumor parenchyma (both P < 0.05) compared with the UT group. There was also an increase in apoptosis following OKN-007 treatment (P < 0.01) compared with UT. CONCLUSION: OKN-007 reduces both necrosis and tumor cell proliferation, as well as seems to mediate multiple effects in different tumor regions (tumor necrotic core and nonnecrotic tumor parenchyma) in F98 gliomas, indicating the efficacy of OKN-007 as an anti-cancer agent and its potential clinical use.

Venous angioplasty and stenting improve pelvic congestion syndrome caused by venous outflow obstruction.

OBJECTIVE: Pelvic congestion syndrome (PCS) is widely thought to be due to ovarian or internal iliac vein reflux. This report of a retrospective review of treatment of nonthrombotic common iliac vein (CIV) or inferior vena cava (IVC) obstruction with relief of symptoms demonstrates an often overlooked pathologic process. Stent placement is evaluated as an effective treatment of PCS due to venous obstruction even if observed left ovarian vein (OV) reflux is left untreated. METHODS: Records from two institutions were reviewed for patients with nonthrombotic venous outflow obstruction and symptoms of PCS severely affecting quality of life. The patients were evaluated with ultrasound, computed tomography (CT), and intravascular ultrasound before stent placement. From January 2008 through May 2013, 19 patients were treated with stents for severe venous outflow obstruction. Although seven patients also were found to have OV reflux, only one of these was treated with left OV coil occlusion. RESULTS: Whereas 10 of the 19 patients presented with a chief complaint of lower extremity pain, edema, or varicose veins, all patients described their pelvic symptoms as their dominant complaint. Ultrasound and CT suggested moderate to severe compression of the left CIV in 18 patients and a high-grade stenosis of the suprarenal IVC in one patient. Venography showed outflow obstruction with pelvic collaterals, and intravascular ultrasound confirmed focal severe stenosis of the involved vein. Follow-up of 1 to 59 months (median, 11 months) revealed complete resolution of pelvic pain in 15 of 19 patients and of dyspareunia in 14 of 17 sexually active patients. Of the 15 patients who experienced left lower extremity pain or edema before treatment, 13 experienced complete resolution after treatment. Imaging follow-up by ultrasound or CT showed 16 of the stents to be widely patent, with 3 minor asymptomatic stenoses. CONCLUSIONS: Nonthrombotic obstruction of the left CIV or IVC is an underappreciated cause of PCS. Venous angioplasty and stenting provide excellent short-term results for such patients, with resolution of chronic pelvic pain and dyspareunia. Venous obstruction should be considered and carefully evaluated in patients presenting with pelvic congestion, and treatment of obstruction alone may solve the patient's symptoms.

Diagnosis and treatment of the pelvic congestion syndrome.

BACKGROUND: Chronic pelvic pain accounts for up to 30% of outpatient gynecologic visits in the United States, potentially affecting up to 40% of the female population during their lifetime. Pelvic congestion syndrome (PCS) is defined as chronic pelvic pain resulting from reflux or obstruction of the gonadal, gluteal, or periuterine veins, sometimes associated with perineal or vulvar varices. It can also be caused by compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta, also known as the nutcracker syndrome. Whereas PCS accounts for up to 30% of patients presenting with chronic pelvic pain, it is frequently underdiagnosed. We reviewed the literature to investigate the current state of the diagnosis and treatment of this disorder. METHODS: An online database search was performed with MEDLINE. MeSH headings included PCS, chronic pelvic pain, ovarian vein reflux, nutcracker syndrome, renal vein obstruction, pelvic varicosities, labial varicosities, embolization, treatment, and therapies. RESULTS: Our MEDLINE search revealed more than 3756 references to chronic pelvic pain. Specific references to PCS, pelvic chronic pain, ovarian vein reflux, nutcracker syndrome, renal vein obstruction, pelvic varicosities, labial varicosities, embolization, treatment, and therapies, however, included only 260 references. Thirty-seven references were small series including fewer than 50 patients or individual case reports documenting medical, surgical, or endovascular treatment of PCS. The majority of these papers demonstrated successful treatment of symptoms from PCS with embolization of one or both ovarian veins in addition to treatment of refluxing internal iliac vein branches. In addition, open surgery and, more recently, endovascular stenting of LRV obstruction have shown some promise in alleviating symptoms attributed to nutcracker syndrome. CONCLUSIONS: Diagnosis of PCS requires a careful history, physical examination, and noninvasive imaging. Several large case series have demonstrated the efficacy of embolotherapy in the reduction of pelvic pain; thus, it is the most favored treatment option for patients with PCS. For patients with outflow obstruction due to nutcracker syndrome, a limited number of studies have demonstrated remission of symptoms with stenting of the LRV as an alternative to open surgery.

RNA interference targeting hypoxia-inducible factor 1α via a novel multifunctional surfactant attenuates glioma growth in an intracranial mouse model.

OBJECT: High-grade gliomas are the most common form of adult brain cancer, and patients have a dismal survival rate despite aggressive therapeutic measures. Intratumoral hypoxia is thought to be a main contributor to tumorigenesis and angiogenesis of these tumors. Because hypoxia-inducible factor 1α (HIF-1α) is the major mediator of hypoxia-regulated cellular control, inhibition of this transcription factor may reduce glioblastoma growth. METHODS: Using an orthotopic mouse model with U87-LucNeo cells, the authors used RNA interference to knock down HIF-1α in vivo. The small interfering RNA (siRNA) was packaged using a novel multifunctional surfactant, 1-(aminoethyl) iminobis[N-(oleicylcysteinylhistinyl-1-aminoethyl)propionamide] (EHCO), a nucleic acid carrier that facilitates cellular uptake and intracellular release of siRNA. Stereotactic injection was used to deliver siRNA locally through a guide-screw system, and delivery/uptake was verified by imaging of fluorescently labeled siRNA. Osmotic pumps were used for extended siRNA delivery to model a commonly used human intracranial drug-delivery technique, convection-enhanced delivery. RESULTS: Mice receiving daily siRNA injections targeting HIF-1α had a 79% lower tumor volume after 50 days of treatment than the controls. Levels of the HIF-1 transcriptional targets vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUT-1), c-MET, and carbonic anhydrase-IX (CA-IX) and markers for cell growth (MIB-1 and microvascular density) were also significantly lower. Altering the carrier EHCO by adding polyethylene glycol significantly increased the efficacy of drug delivery and subsequent survival. CONCLUSIONS: Treating glioblastoma with siRNA targeting HIF-1α in vivo can significantly reduce tumor growth and increase survival in an intracranial mouse model, a finding that has direct clinical implications.