Endovascular management of nutcracker syndrome in an adolescent patient population.

BACKGROUND: Nutcracker syndrome is defined as left renal vein compression with concomitant clinical symptoms that include flank pain and hematuria. Historically, pediatric and adolescent patients with mild symptoms of nutcracker syndrome were simply observed while those with more severe symptoms underwent left renal vein transposition. Endovascular stenting of the left renal vein is a potentially efficacious and less invasive alternative for managing nutcracker syndrome in adolescents. OBJECTIVE: The purpose of this study was to investigate the technical feasibility, efficacy and safety of left renal vein stenting in adolescents with nutcracker syndrome. MATERIALS AND METHODS: We conducted a retrospective review of electronic medical records and imaging archives to identify adolescents undergoing endovascular stenting for nutcracker syndrome. We reviewed patient demographics including age, gender, presenting symptoms and diagnostic imaging findings. We compared pre- and post-stent deployment intravascular ultrasound (IVUS) and venography and evaluated patient symptoms in clinic up to 6 months following stent placement. RESULTS: Ten patients (average age 16 years, range 12-20 years) underwent 13 procedures. Initial symptoms included pain (n=10) and gross hematuria (n=5). Diagnostic imaging studies included CT abdomen pelvis (n=8), retroperitoneal US (n=6), MRI abdomen/pelvis (n=4), scrotal US (n=2), pelvic US (n=1) and renal Doppler US (n=2). Venography and IVUS demonstrated venous collaterals, proximal blanching at the left-renal-vein-IVC junction, pre-stenotic dilation and intraluminal compression. Most patients (n=9) experienced symptomatic resolution; however, three patients required reintervention to achieve asymptomatic status. No periprocedural complications occurred. CONCLUSION: In this carefully selected adolescent cohort, left renal vein stenting for nutcracker syndrome was often technically feasible, safe and effective in symptom management.

The Role of Interventional Radiologists in the Treatment of Congenital Lymphatic Malformations.

Lymphatic malformations are low-flow vascular malformations that are typically apparent in the pediatric population and can cause significant functional limitations and effects on quality of life. While surgical resection has historically been the mainstay of therapy, percutaneous sclerotherapy has garnered increasing popularity due to its efficacy and low complication rates. The role of interventional radiology in the multidisciplinary management of these often complex malformations requires thorough understanding of the disease process. This article will review the pathophysiology, clinical presentation, imaging workup, and management options of lymphatic malformations. Special attention will be devoted to available sclerosants, the mammalian target of rapamycin inhibitor sirolimus, and complex lymphatic anomalies.

Invasive Procedural Treatments for Symptomatic Uterine Fibroids: A Cost Analysis.

PURPOSE: The aim of this study was to evaluate the contemporary use of procedural interventions to treat symptomatic uterine fibroids and assess associated health care system costs. METHODS: Using the IBM Watson MarketScan Commercial Claims and Encounters database for 2009 to 2015 and relevant International Classification of Diseases diagnosis codes, women aged 18 to 55 years with clinically significant uterine fibroids were identified. Using Current Procedural Terminology codes, relevant procedural interventions were identified (hysterectomy, endometrial ablation, myomectomy, and uterine fibroid embolization [UFE]). Costs were defined as total actual payments by insurers and patients (per procedure and per episode of care) and were adjusted and compared using generalized linear models. RESULTS: Of 241,757 invasive procedures for fibroids, hysterectomy was most common (76.5%), followed by endometrial ablation (14.5%), myomectomy (4.7%), and UFE (4.3%). Hysterectomy was more common in older women and those in rural areas (65.2% of patients <40 years of age, 77.6% of those 40-49 years of age, and 83.6% of those 50-55 years of age; 83.9% of patients outside versus 75.3% within metropolitan statistical areas). Per procedure, adjusted mean costs were $3,188 (95% confidence interval [CI], $3,114-$3,264) for hysterectomy, $2,781 (95% CI, $2,695-$2,870) for ablation, $4,436 (95% CI, $4,256-$4,623) for myomectomy, and $6,161 (95% CI, $5,736-$6,617) for UFE. Adjusted mean costs for entire episodes of care were $14,676 (95% CI, $14,496-$14,858) for hysterectomy, $6,702 (95% CI, $6,534-$6,875) for endometrial ablation, $14,791 (95% CI, $14,465-$15,125) for myomectomy, and $13,873 (95% CI, $13,182-$14,599) for UFE. CONCLUSIONS: Of invasive procedures for symptomatic uterine fibroids, hysterectomy was used more frequently than endometrial ablation, myomectomy, and UFE combined. Per procedure and per episode, ablation was least costly. Costs per episode were similar for hysterectomy, myomectomy, and UFE.

Systematic Review of Contemporary Evidence for the Management of T1 Renal Cell Carcinoma: What IRs Need to Know for Kidney Cancer Tumor Boards.

Renal cell carcinoma is a relatively common malignancy, with 60 to 70 thousand cases a year in the United States alone. Increased utilization of cross-sectional imaging has led to an increase in the number of early renal cell cancers seen by the medical establishment. In addition, certain patient populations have an increased risk of developing kidney cancers which may mandate aggressive screening protocols. This article discusses the epidemiology of renal cell cancers; discusses the current management guidelines from multiple specialty societies; discusses some of the surgical and interventional techniques used in the treatment of such lesions; and provides a review of the literature regarding treatments of early-stage renal cell cancers.

Intima-media thickness at different arterial segments in pediatric type 1 diabetes patients and its relationship with advanced glycation end products.

BACKGROUND: Patients with type 1 diabetes mellitus (T1DM) are at risk for premature atherosclerosis (AS), which has its origin in childhood. Carotid intima-media thickness (IMT) is an established surrogate marker for subclinical AS in adults. The first macroscopically detectable AS changes, however, begin in the abdominal aorta. Advanced glycation end products (AGE) predict microvascular complications in diabetes. OBJECTIVES: To assess the sensitivity for early macrovascular changes of brachial, femoral, and aortic IMT compared to conventional carotid IMT in pediatric T1DM patients ; and the relationship of IMT with AGE. METHODS: Using high-resolution external ultrasound, carotid, brachial, femoral, and aortic IMT were prospectively analyzed in children and adolescents with established T1DM and in controls (Ctrls). AGE were estimated by skin intrinsic fluorescence (SIF). Other established cardiovascular risk factors were excluded. RESULTS: Seventy-six subjects (T1DM = 38; Ctrls = 38) with a mean age of 13.1 ± 4.0 years (6-19, median 13) qualified for analysis. Carotid, brachial, femoral, and aortic IMT analyses were feasible in 100%, 74%, 84%, and 92% of subjects, respectively. Aortic and femoral IMT were increased in T1DM patients (0.60 ± 0.11 vs 0.52 ± 0.10 mm, P < .001; and 0.41 ± 0.07 vs 0.36 ± 0.07 mm, P < .01, respectively) while carotid and brachial IMT were not. AGE levels were elevated in T1DM patients and correlated with aortic IMT only. The influence of AGE on aIMT did not remain significant after adjusting for T1DM and age in our small population. CONCLUSION: We found aortic IMT-and to a lesser degree femoral IMT-to be more sensitive than carotid and brachial IMT for detecting early macrovascular changes in pediatric T1DM patients.

The carbon concentrating mechanism in Chlamydomonas reinhardtii: finding the missing pieces.

The photosynthetic, unicellular green alga, Chlamydomonas reinhardtii, lives in environments that often contain low concentrations of CO2 and HCO3 (-), the utilizable forms of inorganic carbon (Ci). C. reinhardtii possesses a carbon concentrating mechanism (CCM) which can provide suitable amounts of Ci for growth and development. This CCM is induced when the CO2 concentration is at air levels or lower and is comprised of a set of proteins that allow the efficient uptake of Ci into the cell as well as its directed transport to the site where Rubisco fixes CO2 into biomolecules. While several components of the CCM have been identified in recent years, the picture is still far from complete. To further improve our knowledge of the CCM, we undertook a mutagenesis project where an antibiotic resistance cassette was randomly inserted into the C. reinhardtii genome resulting in the generation of 22,000 mutants. The mutant collection was screened using both a published PCR-based approach (Gonzalez-Ballester et al. 2011) and a phenotypic growth screen. The PCR-based screen did not rely on a colony having an altered growth phenotype and was used to identify colonies with disruptions in genes previously identified as being associated with the CCM-related gene. Eleven independent insertional mutations were identified in eight different genes showing the usefulness of this approach in generating mutations in CCM-related genes of interest as well as identifying new CCM components. Further improvements of this method are also discussed.