25 research outputs found

    Nanofabrication by magnetic focusing of supersonic beams

    Full text link
    We present a new method for nanoscale atom lithography. We propose the use of a supersonic atomic beam, which provides an extremely high-brightness and cold source of fast atoms. The atoms are to be focused onto a substrate using a thin magnetic film, into which apertures with widths on the order of 100 nm have been etched. Focused spot sizes near or below 10 nm, with focal lengths on the order of 10 microns, are predicted. This scheme is applicable both to precision patterning of surfaces with metastable atomic beams and to direct deposition of material.Comment: 4 pages, 3 figure

    Systematic review and meta-analysis of surgical interventions for high cryptoglandular perianal fistula.

    No full text
    PURPOSE: Perianal fistulas, and specifically high perianal fistulas, remain a surgical treatment challenge. Many techniques have, and still are, being developed to improve outcome after surgery. A systematic review and meta-analysis was performed for surgical treatments for high cryptoglandular perianal fistulas. METHODS: Medline (Pubmed, Ovid), Embase and The Cochrane Library databases were searched for relevant randomized controlled trials on surgical treatments for high cryptoglandular perianal fistulas. Two independent reviewers selected articles for inclusion based on title, abstract and outcomes described. The main outcome measurement was the recurrence/healing rate. Secondary outcomes were continence status, quality of life and complications. RESULTS: The number of randomized trials available was low. Fourteen studies could be included in the review. A meta-analysis could only be performed for the mucosa advancement flap versus the fistula plug, and did not show a result in favour of either technique in recurrence or complication rate. The mucosa advancement flap was the most investigated technique, but did not show an advantage over any other technique. Other techniques identified in randomized studies were seton treatment, medicated seton treatment, fibrin glue, autologous stem cells, island flap anoplasty, rectal wall advancement flap, ligation of intersphincteric fistula tract, sphincter reconstruction, sphincter-preserving seton and techniques combined with antibiotics. None of these techniques seem superior to each other. CONCLUSIONS: The best surgical treatment for high cryptoglandular perianal fistulas could not be identified. More randomized controlled trials are needed to find the best treatment. The mucosa advancement flap is the most investigated technique available

    Use of covered stent grafts as treatment of traumatic venous injury to the inferior vena cava and iliac veins: A systematic review

    No full text
    Objective: Venous injury to the inferior vena cava or iliac veins is rare but can result in high mortality rates. Traditional treatment by repair or ligation can be technically demanding. A relatively new treatment modality is the use of a covered stent to cover the venous defect. The aim of the present systematic review was to assess the techniques, results, and challenges of covered stent graft repair of traumatic injury to the inferior vena cava and iliac veins.Methods: The PubMed (Medline) and Embase databases were systematically searched up to September 2020 by two of us (R.R.S. and D.D.) independently for studies reporting on covered stenting of the inferior vena cava or iliac veins after traumatic or iatrogenic injury. A methodologic quality assessment was performed using the modified Newcastle-Ottawa scale. Data were extracted for the following parameters: first author, year of publication, study design, number of patients, type and diameter of the stent graft, hemostatic success, complications, mortality, postoperative medication, follow-up type and duration, and venous segment patency. The main outcome was clinical success of the intervention, defined as direct hemostasis, with control of hemorrhage, hemodynamic recovery, and absence of contrast extravasation.Results: From the initial search, which yielded 1884 records, a total of 28 studies were identified for analysis. All reports consisted of case reports, except for one retrospective cohort study and one case series. A total of 35 patients had been treated with various covered stent grafts, predominantly thoracic or abdominal aortic endografts. In all patients, the treatment was technically successful. The 30-day mortality rate for the entire series was 2.9%. Three perioperative complications were described: one immediate stent occlusion, one partial thrombosis, and one pulmonary embolism. Additional in-stent thrombus formation was seen during follow-up in three patients, leading to one stent graft occlusion (asymptomatic). The postoperative anticoagulation strategy was highly heterogeneous. The median follow-up was 3 months (range, 0.1-84 months). However, follow-up with imaging studies was not performed in all cases.Conclusions: In selected cases of injury to the inferior vena cava and iliac veins, covered stent grafts can be successful for urgent hemostasis with good short-term results. Data on long-term follow-up are very limited

    Treatment of Crohn's disease-related high perianal fistulas combining the mucosa advancement flap with platelet-rich plasma: a pilot study

    Get PDF
    BACKGROUND: Healing rates after surgical closure for high perianal fistula in patients with Crohn's disease are even more disappointing than in patients with cryptoglandular fistulas. The objective was to improve healing rates by combining the well-known mucosal advancement flap with platelet-rich plasma. METHODS: A prospective pilot study was conducted in one tertiary referral centre. Consecutive patients with primary or recurrent Crohn's disease-related high perianal fistulas, defined as involving the middle and/or upper third parts of the anal sphincter complex, were included. A staged procedure was performed with non-cutting seton treatment for 3 months first, followed by a mucosal advancement flap with injection of platelet-rich plasma into the fistula tract. RESULTS: Ten consecutive patients were operated on between 2009 and 2014. Half (50 %) of the patients had undergone previous fistula surgery. Mean follow-up was 23.3 months (SD 13.0). Healing of the fistula was 70 % (95 % confidence interval, 33-89 %) at 1 year. One (10 %) patient had a recurrence, and in two (20 %) patients, the fistula was persistent after treatment. An abscess occurred in one (10 %) patient. The median post-operative Vaizey score was 8.0 (range 0-21), indicating a moderate to severe continence impairment. CONCLUSIONS: The results of combining the mucosal advancement flap with platelet-rich plasma in patients with Crohn's disease-related high perianal fistulas are moderate with a healing rate of 70 %. Further investigation is needed to determine the benefits and risks on continence status for this technique in this patient population

    Long-term Results of Mucosal Advancement Flap Combined With Platelet-rich Plasma for High Cryptoglandular Perianal Fistulas

    No full text
    BACKGROUND: The long-term closure rate of high perianal fistulas after treatment remains disappointing. OBJECTIVE: The goal of this study was the long-term closure rate of high cryptoglandular perianal fistulas mucosal advancement flap with platelet-rich plasma. DESIGN: This study retrospective in design. SETTING: This study was conducted at 2 tertiary referral hospitals. PATIENTS: Patients presenting with high cryptoglandular perianal fistulas involving the middle/upper third of sphincter complex were included. INTERVENTIONS: A staged surgical performed; After seton placement, a mucosal advancement flap was platelet-rich plasma. MAIN OUTCOME MEASURES: Recurrence was the main Incontinence was the secondary outcome. RESULTS: We operated on 25 between 2006 and 2012. Thirteen (52%) patients had previous fistula median follow-up period was 27 months. One patient (4.0%) was lost to after 4 months. Freedom from recurrence at 2 years was 0.83 (95% CI, Two of the 4 patients with a recurrence (8%) had a repeated treatment One patient (4.0%) refused another treatment, but agreed to stay in One patient (4.0%) requested a colostomy, resulting in closure of the Complications occurred in 1 patient (4.0%). Incontinence numbers were median Vaizey score of 3.0 out of a maximum of 24. LIMITATIONS: The limited by its retrospective design, lack of preoperative incontinence selection bias, and phone interview follow-up. CONCLUSION: The long-term results of patients with primary and recurrent high cryptoglandular fistulas treated with a seton followed by mucosal advancement flap and platelet-rich plasma show low recurrence, complication, and incontinence Therefore, this technique seems to be a valid option as treatment. preferably randomized controlled studies are needed to further explore surgical technique

    Hypomethylation is restricted to the D4Z4 repeat array in phenotypic FSHD.

    No full text
    Contains fulltext : 52246.pdf (publisher's version ) (Closed access)BACKGROUND: Patients with facioscapulohumeral muscular dystrophy (FSHD) show a contraction of the D4Z4 repeat array in the subtelomere of chromosome 4q. This D4Z4 contraction is associated with significant allele-specific hypomethylation of the repeat. Hypomethylation of D4Z4 is also observed in patients with phenotypic FSHD without contraction of D4Z4 and in patients with the immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome, an unrelated disease that does not present with muscular dystrophy and is in part caused by DNMT3B mutations. METHODS: In order to identify the gene defect and to find the pathogenetic epigenetic pathway in phenotypic FSHD, we have aimed to identify the differences and commonalities in phenotypic FSHD and ICF by 1) investigation of DNA methylation of non-D4Z4 repeat arrays, 2) analysis of mitogen-stimulated lymphocytes to detect pericentromeric abnormalities involving chromosomes 1, 9, and 16, 3) determination of IgA, IgG, and IgM levels, and 4) mutational analysis of candidate genes to identify a second disease locus involved in the pathogenesis of phenotypic FSHD. RESULTS: Our results do not show epigenetic or phenotypic commonalities between phenotypic FSHD and ICF other than the earlier observed D4Z4 hypomethylation. We could not identify any mutations in the candidate genes tested for. CONCLUSION: Our data suggest that in phenotypic FSHD hypomethylation is restricted to D4Z4 and that phenotypic FSHD and ICF do not share a defect in the same molecular pathway
    corecore