Café-au-lait macules: occasional fatal sequels of benign pigmented lesions

We report a case of sudden death in a 28-year-old male diagnosed with neurofibromatosis at the age of 6 years. The patient had multiple café-au-lait spots which, although being benign, were an ominous sign in this context. The immediate cause of death was intrathoracic neurofibroma causing compression that led to fracture of the thoracic vertebrae and laceration of the aorta with massive hemothorax.     

Correlation of tumor size with other prognostic factors in uterine serous carcinoma: A large multi-institutional study

ObjectiveUterine serous carcinoma (USC) constitutes 10% of uterine cancers but ~ 40% of deaths. Tumor size is a known prognostic factor in other solid tumors. In endometriod cancers it is one element used to identify the need for complete staging, while its significance in USC is debated. Therefore tumor size was examined as an independent prognostic factor.MethodsClinical and pathologic variables were recorded for 236 institutional patients, and those patients in the SEER database with USC. Chi-square and Fisher exact t-tests were utilized and survival data generated via Kaplan–Meier method; multivariate analysis was performed via cox-regression.ResultsThe patients' mean age was 67.2 years (range 40–91). Survival ranged from 0 to 184 months (mean 42.8). We used a tumor size cut-off of 1 cm and noted significant associations with myometrial invasion (p < 0.0001), angiolymphatic invasion (p < 0.0001), peritoneal washings (p = 0.03), stage (p = 0.015) and positive lymph nodes (p = 0.05). Furthermore, recurrence was associated with larger tumors (p = 0.03). In multivariate analysis, extra-uterine disease was the only factor associated with both recurrence and survival. Review of the SEER database noted association of larger tumors with lymph node involvement and a significant survival advantage with tumors < 1 cm in both univariate and multivariate analysis.ConclusionsTreatment options for USC are often predicated on the surgical stage and therefore components of the staging are vitally important. The 1 cm tumor-size cut-off should be studied prospectively as a prognostic indicator of survival and recurrence in USC and considered for inclusion in USC staging.     

Mechanochemical Endovenous Ablation of Varicose Veins in Pediatric Patients with Klippel-Trénaunay Syndrome: Feasibility,Safety, and Initial Results

PurposeTo evaluate feasibility, safety, and results of endovenous mechanochemical ablation (MOCA) for treatment of persistent embryonic and dysplastic veins in pediatric patients with Klippel-Trénaunay syndrome (KTS).Materials and MethodsThirteen MOCA procedures were performed in 11 patients (age range, 4–16 years) with KTS and symptomatic persistent embryonic or dysplastic veins during a 24-month period. All patients were evaluated with color Doppler (CD) ultrasound (US), contrast-enhanced MR imaging, and venography to assess the anatomy of the target vessels and patency of the deep venous system. All procedures were performed under general anesthesia with a ClariVein catheter and liquid sodium tetradecyl sulfate as the sclerosing agent. US and fluoroscopic guidance were used in all cases. Technical success rate, primary occlusion rate, adverse effects, and recanalization rates were evaluated. Clinical and radiological (CD US) controls were performed 1 day, 7 days, 1 month, and 6 months after the procedure and once a year thereafter, with a mean follow-up of 16 months (range, 6–25 months).ResultsTechnical success and primary occlusion were achieved in all patients with no adverse events. During the follow-up period, CD US demonstrated partial recanalization and symptom recurrence in 2 patients (18%), 14 and 18 months after the initial procedure. These 2 patients had a second ablation procedure with no recanalization or symptom recurrence during the subsequent follow-up period.ConclusionsMOCA is feasible and appears to be a safe and effective technique for treatment of varicose veins in pediatric patients with KTS.     

Safety and Efficacy of Paclitaxel-Eluting Balloon Angioplasty for Dysfunctional Hemodialysis Access: A randomized trial Comparing with Angioplasty Alone

PurposeTo assess whether angioplasty of hemodialysis access (HA) stenosis with a drug-coated balloon (DCB) would prevent restenosis in comparison with plain-balloon percutaneous transluminal angioplasty (PTA).Materials and MethodsThis prospective randomized clinical trial enrolled 120 patients with dysfunctional arteriovenous fistulae (n = 109) and grafts (n = 11), due to a ≥50% stenosis between March 2014 and April 2018. All patients underwent high-pressure balloon angioplasty and were then randomized to either DCB (n = 60) or PTA (n = 60). Patients were followed-up for 1 year, and angiography was performed 6 months after angioplasty. The primary endpoint was the late lumen loss (LLL) at 6 months. Secondary endpoints included other angiographic parameters at 6 months and HA failures, adverse event, and mortality at 12 months. Continuous variables were compared with a Student t-test, and Kaplan-Meier curves were used for freedom from HA failure and for mortality.ResultsLLL in the DCB and in the PTA group were 0.64 mm ± 1.20 and 1.13 mm ± 1.51, respectively (P = .082, adjusted P = .0498). DCB was associated with lower percentage stenosis (54.2% ± 19.3 vs 61.7% ± 18.2; P = .047) and binary restenosis ≥50% (56.5% vs 81.1%; P = .009) than PTA. The number of HA failures after 12 months was lower for DCB than for PTA (45% vs 66.7%; P = .017). Mortality at 12 months was 10% and 8.3% in the DCB and PTA groups, respectively (P = .75).ConclusionsDespite LLL improvement that failed to reach statistical significance, this study demonstrated decreased incidence and severity of restenosis with DCB compared with PTA to treat dysfunctional HA.     

Optimization of spatial resolution for peripheral magnetic resonance angiography

RATIONALE AND OBJECTIVES: To determine optimum spatial resolution when imaging peripheral arteries with magnetic resonance angiography (MRA). MATERIALS AND METHODS: Eight vessel diameters ranging from 1.0 to 8.0 mm were simulated in a vascular phantom. A total of 40 three-dimensional flash MRA sequences were acquired with incremental variations of fields of view, matrix size, and slice thickness. The accurately known eight diameters were combined pairwise to generate 22 "exact" degrees of stenosis ranging from 42% to 87%. Then, the diameters were measured in the MRA images by three independent observers and with quantitative angiography (QA) software and used to compute the degrees of stenosis corresponding to the 22 "exact" ones. The accuracy and reproducibility of vessel diameter measurements and stenosis calculations were assessed for vessel size ranging from 6 to 8 mm (iliac artery), 4 to 5 mm (femoro-popliteal arteries), and 1 to 3 mm (infrapopliteal arteries). Maximum pixel dimension and slice thickness to obtain a mean error in stenosis evaluation of less than 10% were determined by linear regression analysis. RESULTS: Mean errors on stenosis quantification were 8.8% +/- 6.3% for 6- to 8-mm vessels, 15.5% +/- 8.2% for 4- to 5-mm vessels, and 18.9% +/- 7.5% for 1- to 3-mm vessels. Mean errors on stenosis calculation were 12.3% +/- 8.2% for observers and 11.4% +/- 15.1% for QA software (P = .0342). To evaluate stenosis with a mean error of less than 10%, maximum pixel surface, the pixel size in the phase direction, and the slice thickness should be less than 1.56 mm2, 1.34 mm, 1.70 mm, respectively (voxel size 2.65 mm3) for 6- to 8-mm vessels; 1.31 mm2, 1.10 mm, 1.34 mm (voxel size 1.76 mm3), for 4- to 5-mm vessels; and 1.17 mm2, 0.90 mm, 0.9 mm (voxel size 1.05 mm3) for 1- to 3-mm vessels. CONCLUSION: Higher spatial resolution than currently used should be selected for imaging peripheral vessels.     

Evaluation of Renal Function in Patients Undergoing Lung Transplantation

Background

Acute kidney injury and chronic kidney failure are serious complications after lung transplantation. Glomerular filtration rate (GFR) is the primary indicator of renal function. Several equations have been proposed to evaluate the estimated GFR (eGFR). We compared three different equations to determine which has the better correlation with the development of acute and chronic renal failure in lung recipients.

Minimally Invasive Achilles Tendon Stripping for the Management of Tendinopathy of the Main Body of the Achilles Tendon

Achilles tendinopathy is a common cause of disability. New nerves fibers grow from the paratenon into the Achilles tendon, and they could play a central role in the development of pain. We report the results of minimally invasive Achilles tendon stripping for Achilles tendinopathy in 47 active patients. The Victorian Institute of Sports Assessment-Achilles questionnaire score improved from 53.8 preoperatively to 85.3 postoperatively (p < .001). After a mean follow-up period of 40.5 months, 41 patients had resumed sporting activities at an average of 3.5 months postoperatively. A sural nerve injury was recorded in 5 patients (10.6%), and all 5 complications occurred during the first 12 cases. As a result, the technique was slightly modified, and no sural nerve neuropathy was observed subsequently. One superficial infection (2.1%) was recorded. Minimally invasive Achilles tendon stripping seems to be an effective, technically simple, and inexpensive treatment of Achilles tendinopathy. Further randomized controlled trials involving more patients are needed to confirm these outcomes.     

Evaluation of the retrievability of the OptEase IVC filter in an animal model

PURPOSE: A new inferior vena cava filter was evaluated in vivo to determine the percutaneous retrievability after an implantation period of up to 18 days. MATERIALS AND METHODS: The inferior venae cavae of six goats were percutaneously implanted with three filters, and one animal received two filters. To assess filter stability, a plain radiograph was obtained after 7-9 days and on the day of retrieval. After cavography, filter retrieval with an endovascular snare and retrieval catheter was performed in three animals after 12 days and in three others after 14 days. In one animal, retrieval of one filter was performed after 18 days, and one filter was intended to be permanent. Twenty-eight days after filter retrieval, cavography was performed before inferior vena cava removal for gross and histologic examination. RESULTS: All filters (N = 20) were implanted without complications. There was no migration during the implantation period. Preretrieval cavography demonstrated all filters to be patent and centered. Filters intended for retrieval (n = 19) were all successfully extracted at 12 (nine filters), 14 (nine filters), and 18 days (one filter). For the animal with the filter extracted at 18 days, one filter remained in situ intentionally. Postretrieval cavography showed no visible signs of vessel wall anomalies. There were no complications during the 28 days of follow-up after retrieval. Presacrifice cavography showed no evidence of caval wall abnormalities. In all animals, gross examination of the inner wall of the explanted vena cava showed only minimal macroscopic changes. The struts of the filter in situ for 46 days (18 days with 28 days of follow-up) were overgrown with neointima. Histological study of the 19 filter retrieval sites revealed no to moderate intima proliferation, minimal residual signs of hemorrhages, and no or only occasional slight inflammatory reaction. CONCLUSIONS: In this animal model, the new vena cava filter demonstrated event-free retrieval, without postretrieval complications, up to 18 days postimplantation. After implantation of 46 days, the filter showed neointima overgrowth of the struts.     

Cross-Linguistic Cognitive Modeling of Verbal Morphology Acquisition

How children acquire and process inflectional morphology is still an open question. Despite the fact that English past tense acquisition has been studied and modeled in depth, the current approaches do not account for many of the errors made by humans. Moreover, not much work has been done with highly inflected languages, like Spanish. However, the modeling of any linguistic phenomenon in different languages is very important in order to understand the general cognitive processes underlying each particular phenomenon. This paper presents an ACT-R dual-mechanism model that accomplishes the task of acquiring verbal morphology systems from one of the simplest systems (the English one) to one of the most complex systems (the Spanish one), by using a double analogy process of stem and suffix. The model proposed was able to match all types of errors that developing children make (from a sample of them), both in English and Spanish. The models for both languages used very similar parameters. The introduced approach not only shows how children could acquire a highly inflected morphology system in terms of dual-mechanism theories but, given its cross-linguistic character, also sheds light on the possible general processes involved in the acquisition and processing of inflectional morphology.     

CT and MR imaging of nitinol stents with radiopaque distal markers

PURPOSE: To evaluate imaging characteristics and artifacts of a nitinol stent with distal tantalum markers with computed tomography (CT) angiography and magnetic resonance (MR) angiography. MATERIALS AND METHODS: A vascular phantom was built to simulate in-stent restenosis. A nitinol stent with tantalum markers (Luminexx stent) was evaluated with CT angiography in different orientations relative to the z-axis and with MR angiography in different positions relative to both B0 and the readout gradient. Stenosis measurements were compared with conventional digital subtraction angiography for both modalities. In-stent signal intensity obtained with different flip angles was assessed in two nitinol stents with distal markers (Luminexx stent and SMART stent) and one without markers (Memotherm-FLEXX stent). RESULTS: Stenosis detection was not possible with CT angiography when the stent was perpendicular to the z-axis because of streak-like artifacts induced by tantalum markers. Stenosis evaluation with multiplanar reformation was accurate when the stent was in parallel and oblique orientations relative to the table axis. With MR angiography, metallic artifacts were mostly related to the stent orientation with B0, whereas orientation of the readout gradient had little influence. The mean error (overestimation) for stenosis measurements varied between 0.1% and 7.4% for CT imaging in parallel and oblique positions and 3.6% and 9.5% for MR imaging. Higher flip angles did not improve signal intensity inside the three stents tested. CONCLUSION: CT and MR angiography can be used for evaluating the patency of stents with distal markers that are parallel or oblique relative to the table axis (iliac, carotid, or femoral stents). MR angiography is preferred if the stent is perpendicular to the table axis (renal stent).