Micro-metric electronic patterning of a topological band structure using a photon beam.

In an ideal 3D topological insulator (TI), the bulk is insulating and the surface conducting due to the existence of metallic states that are localized on the surface; these are the topological surface states. Quaternary Bi-based compounds of Bi(2-x)Sb(x)Te(3-y)Se(y) with finely-tuned bulk stoichiometries are good candidates for realizing ideal 3D TI behavior due to their bulk insulating character. However, despite its insulating bulk in transport experiments, the surface region of Bi(2-x)Sb(x)Te(3-y)Se(y) crystals cleaved in ultrahigh vacuum also exhibits occupied states originating from the bulk conduction band. This is due to adsorbate-induced downward band-bending, a phenomenon known from other Bi-based 3D TIs. Here we show, using angle-resolved photoemission, how an EUV light beam of moderate flux can be used to exclude these topologically trivial states from the Fermi level of Bi1.46Sb0.54Te1.7Se1.3 single crystals, thereby re-establishing the purely topological character of the low lying electronic states of the system. We furthermore prove that this process is highly local in nature in this bulk-insulating TI, and are thus able to imprint structures in the spatial energy landscape at the surface. We illustrate this by 'writing' micron-sized letters in the Dirac point energy of the system.

Sapheon: the solution?

Less invasive endovenous techniques have been shown to be as effective as open surgery in the treatment of varicose veins. Furthermore, they cause less postoperative bruising and pain and enable early return to normal activities and work. Tumescent anaesthesia is safe and obviates complications of general or spinal anaesthesia. Drawbacks are a steep learning curve and painful administration during treatment. Tumescentless techniques like Clarivein™ or VenaSeal™ Sapheon Closure System are recently under investigation. Short-term results of VenaSeal™ are comparable with thermal ablation. The procedure is safe without serious adverse events. Perioperative pain and patient discomfort with this tumescentless approach is minimal but postoperative recovery is temporarily hindered by thrombophlebitis in 14-15 % of patients. One-year results in a small feasibility study has demonstrated durable closure at this endpoint. No longer-term results are available. A randomized control trial between VenaSeal™ and Covidien ClosureFast™ is in a preparatory phase.

Detection of varicose vein recurrence by duplex ultrasound: intra- and interobserver reproducibility.

In a long-term follow-up study comparing saphenofemoral ligation and stripping with endovenous laser ablation, the groin is examined yearly by duplex ultrasound (DUS) to detect postoperative varicose vein recurrence. Clear criteria are needed for the uniformity of DUS observations. Physicians taking care of the follow-up were evaluated by an intra- and interobserver analysis. DUS films of 22 patients with no recurrence and 22 patients with recurrence of varicose veins were twice interpreted in two sessions. Observations were analysed by a kappa test. Interpretations of DUS by experienced observers show a kappa >7. Improved kappa results were measured over time in our physician in training. In conclusion, the reproducibility of DUS studies performed by the experienced observers of the study is excellent.

Randomised controlled trial comparing sapheno-femoral ligation and stripping of the great saphenous vein with endovenous laser ablation (980 nm) using local tumescent anaesthesia: one year results.

OBJECTIVES: Comparison of sapheno-femoral ligation and stripping (SFL/S) versus endovenous laser ablation (EVLA, 980-nm) in the treatment of great saphenous vein (GSV) insufficiency, using local tumescent anaesthesia. DESIGN: Randomised, single centre trial. MATERIALS AND METHODS: Patients with GSV incompetence and varicose veins were randomised to either SFL/S or EVLA. At days 1, 2, 3, 7, 10, and 14 post-treatment, patients completed questionnaires on pain and quality of life. Recurrent varicose veins were evaluated by Duplex ultrasound (DUS) performed at 1 and 6 weeks, and 6 and 12 months. RESULTS: 130 legs in 121 patients were treated by SFL/S (n=68) or EVLA (n=62). Significantly more post-treatment pain was noted after EVLA at days 7, 10 and 14 (p<0.01; p<0.01; p=0.01), more hindrance in mobility at days 7 (p<0.01) and 10 (p=0.01), and in self care (p=0.03) and daily activities (p=0.01) at day 7 compared to SFL/S. DUS at 1-year follow-up showed 9% recurrences (5/56) after EVLA and 10% (5/49) after SFL/S. CONCLUSION: Both SFL/S and EVLA, using local tumescent anaesthesia, were well tolerated, with no difference in short-term recurrence rate. In the second week after EVLA, patients experienced significantly more pain resulting in restricted mobility, self care and daily activity compared to SFL/S.

Temporal endosonographic evaluation of anal sphincter integrity after primary repair for obstetric ruptures: a case for specific training of obstetricians.

OBJECTIVE: To evaluate primary repaired obstetric lesions of the anal sphincter complex on anal endo-ultrasound within a few days and 8 weeks after primary repair and to investigate in this way the influence of suboptimal woundhealing on the final anatomical result. Furthermore to investigate the relation between faecal incontinence and sphincter defects. DESIGN: A prospective cohort study. Setting The obstetric clinic and coloproctology outpatient clinic of the Zaans Medical Centre in Zaandam, the Netherlands. Subjects A cohort of 32 consecutive women with primary surgically repaired 3B, 3C or 4th degree anal sphincter defect after vaginal delivery. MAIN OUTCOME MEASURES: Appearance of the anal sphincter complex on anal endo-ultrasound within a few days week and 8 weeks after primary surgical repair, i.e. first and second ultrasound, respectively. Evaluation of anal continence, using the Vaizey incontinence score, at second ultrasound. RESULTS: No major wound breakdown was seen and four women had superficial, skin related wound problems. Twenty-eight women (87.5%) had a repaired external anal sphincter on the first and the second ultrasound. Of four external anal sphincter defects on first ultrasound one defect was not present on second ultrasound. The internal sphincter showed a defect on first ultrasound in 11 women and this was still present in 10 on second ultrasound. A total of 11 women had a persisting anal sphincter defect (external, internal or in combination). Mean Vaizey scores were significantly higher in women with a persisting sphincter defect (EAS, IAS or in combination) than in women with no sphincter defects, 2.3 and 0.4 respectively (95% CI 0.1-3.6, P = 0.04). CONCLUSION: Anal endo-ultrasound may be used for early evaluation of surgical repair of anal sphincter lesions after vaginal delivery. Persisting defects in the anal sphincters, in this series not because of major wound breakdown, can be explained by inadequate surgical repair.