Monolithic high-index contrast grating: a material independent high-reflectance VCSEL mirror.

In this paper we present an extensive theoretical and numerical analysis of monolithic high-index contrast grating, facilitating simple manufacture of compact mirrors for very broad spectrum of vertical-cavity surface-emitting lasers (VCSELs) emitting from ultraviolet to mid-infrared. We provide the theoretical background explaining the phenomenon of high reflectance in monolithic subwavelength gratings. In addition, by using a three-dimensional, fully vectorial optical model, verified by comparison with the experiment, we investigate the optimal parameters of high-index contrast grating enabling more than 99.99% reflectance in the diversity of photonic materials and in the broad range of wavelengths.

Effectiveness of digital feedback on patient experience and 30-day complications after screening colonoscopy: a randomized health services study.

Background and study aims European guidelines (ESGE) recommend measuring patient experience and 30-day complication rate after colonoscopy. We compared digital and paper-based feedback on patients' experience and 30-day complications after screening colonoscopy. Patients and methods Screenees attending for primary screening colonoscopies in two centers from September 2015 to December 2016 were randomized (1:1) to an intervention arm (choice of feedback method) or control arm (routine paper-based feedback). Participants in the intervention arm could choose preferred feedback method (paper-based, automated telephone or online survey) and were contacted by automated telephone 30 days after colonoscopy to assess complications. Control group participants self-reported complications. Primary and secondary endpoints were response rates to feedback and complications questionnaire, respectively. Results There were 1,281 and 1,260 participants in the intervention and control arms, respectively. There was no significant difference in response rate between study groups (64.8 % vs 61.5 %; P  = 0.08). Free choice of feedback improved response for participants identified as poor responders: younger than 60 years (60.8 % vs 54.7 %; P  = 0.031), male (64.0 % vs 58.6 %; P  = 0.045) and in small non-public center (56.2 % vs 42.5 %; P  = 0.043). In the intervention arm, 1,168 participants (91.2 %) answered the phone call concerning complications. A total of 79 participants (6.2 %) reported complications, of which two (0.2 %) were verified by telephone as clinically relevant. No complications were self-reported in the control group. Conclusion The overall response rate was not significantly improved with digital feedback, yet the technology yielded significant improvement in participants defined as poor responders. Our study demonstrated feasibility and efficacy of digital patient feedback about complications after colonoscopy.

Endoscopic Resections in Inflammatory Bowel Disease: A Multicentre European Outcomes Study.

BACKGROUND AND AIMS: Inflammatory bowel disease is associated with an increased risk of colorectal cancer, with estimates ranging 2-18%, depending on the duration of colitis. The management of neoplasia in colitis remains controversial. Current guidelines recommend endoscopic resection if the lesion is clearly visible with distinct margins. Colectomy is recommended if complete endoscopic resection is not guaranteed. We aimed to assess the outcomes of all neoplastic endoscopic resections in inflammatory bowel disease. METHODS: This was a multicentre retrospective cohort study of 119 lesions of visible dysplasia in 93 patients, resected endoscopically in inflammatory bowel disease. RESULTS: A total of 6/65 [9.2%] lesions <20 mm in size were treated by ESD [endoscopic submucosal dissection] compared with 59/65 [90.8%] lesions <20 mm treated by EMR [endoscopic mucosal resection]; 16/51 [31.4%] lesions >20 mm in size were treated by EMR vs 35/51 [68.6%] by ESD. Almost all patients [97%] without fibrosis were treated by EMR, and patients with fibrosis were treated by ESD [87%], p < 0.001. In all, 49/78 [63%] lesions treated by EMR were resected en-bloc and 27/41 [65.9%] of the ESD/KAR [knife-assisted resection] cases were resected en-bloc, compared with 15/41 [36.6%] resected piecemeal. Seven recurrences occurred in the cohort. Seven complications occurred in the cohort; six were managed endoscopically and one patient with a delayed perforation underwent surgery. CONCLUSIONS: Larger lesions with fibrosis are best treated by ESD, whereas smaller lesions without fibrosis are best managed by EMR. Both EMR and ESD are feasible in the management of endoscopic resections in colitis.

Choice of transplantation techniques and indications for liver transplantation in polycystic liver disease in patients with no signs of end-stage liver disease.

OBJECTIVE: Since the initiation of the Liver Transplant Program, 500 liver procedures have been performed. Polycystic liver disease (PLD) and polycystic kidney-liver disease (PKLD) have been rare indications for orthotopic liver transplantation (OLT). Only 7 patients (1.4%) underwent transplantation due to PLD and PKLD. MATERIALS AND METHODS: The group consisted of 4 patients who underwent OLT (0.8%) and 3 patients who received simultaneous liver kidney transplantation (LKT; 0.6%). Our objective was to analyze the indications for either OLT or combined LKT as well as indications for surgical techniques during OLT among patients with PLD or PKLD. RESULTS: The main indication for OLT was massive hepatomegaly causing severe physical handicaps, fatigue, and clinically advanced malnutrition. All 3 patients with indications for combined LKT were dialysis-dependent. None of the patients had symptoms of end-stage liver disease and/or hepatic failure. In 4 cases, a portal bypass was applied, and the piggy-back method used in the other 3 cases. The hepatectomy caused no uncommon difficulty. In cases of simultaneous transplantations, the kidney was implanted separately after OLT. All patients are alive following the transplantation; major surgical complications have occurred. CONCLUSIONS: Patients with PLD can undergo OLT safely with good results. They benefit from the relief of abdominal distension and anorexia. Patients with PKLD who are dialysis-dependent should undergo simultaneous LKT. The surgical technique was solely dependent on the intraoperative conditions determined during the dissection phase.