Ultrastructural analysis of explanted CyPass microstents and correlation with clinical findings.

PURPOSE: The purpose of this study was to obtain insight into cellular processes after CyPass microstent implantation into the supraciliary space. With this knowledge, we expected to find some reason for surgical failure. METHODS: Nine CyPass microstents of 8 patients with primary open-angle glaucoma (n = 1), pseudoexfoliation glaucoma (n = 5), uveitic glaucoma (n = 1), and posttraumatic open-angle glaucoma (n = 1) were explanted due to recurrence of IOP elevation, corneal decompensation, or persistent hypotony. The explants were processed for light and transmission electron microscopy. RESULTS: Fibrotic material, consisting of collagen fibrils, microfibrils, pseudoexfoliation fibrils produced by activated fibroblasts, was detected in the stent lumen of 4/5 pseudoexfoliation glaucoma patients and also in posttraumatic open-angle glaucoma. Fibrotic material was also present on the outer surface and within fenestrations of the majority of stents. Complete absence of fibrotic reaction was noticed in 3 of 9 microstents. CONCLUSION: Although MIGS is known to be less invasive than conventional surgery, implants placed in the suprachoroidal space may be adversely affected by a fibrotic tissue reaction resulting in implant failure. Understanding mechanisms and risk factors leading to fibrotic scarring following antiglaucomatous surgery may help to develop novel strategies that improve surgical outcome.

A retrospective audit of postoperative days alive and out of hospital, including before and after implementation of the WHO surgical safety checklist.

We implemented the World Health Organization surgical safety checklist at Auckland City Hospital from November 2007. We hypothesised that the checklist would reduce postoperative mortality and increase days alive and out of hospital, both measured to 90 postoperative days. We compared outcomes for cohorts who had surgery during 18-month periods before vs. after checklist implementation. We also analysed outcomes during 9 years that included these periods (July 2004-December 2013). We analysed 9475 patients in the 18-month period before the checklist and 10,589 afterwards. We analysed 57,577 patients who had surgery from 2004 to 2013. Mean number of days alive and out of hospital (95%CI) in the cohort after checklist implementation was 1.0 (0.4-1.6) days longer than in the cohort preceding implementation, p < 0.001. Ninety-day mortality was 395/9475 (4%) and 362/10,589 (3%) in the cohorts before and after checklist implementation, multivariable odds ratio (95%CI) 0.93 (0.80-1.09), p = 0.4. The cohort changes in these outcomes were indistinguishable from longer-term trends in mortality and days alive and out of hospital observed during 9 years, as determined by Bayesian changepoint analysis. Postoperative mortality to 90 days was 228/5686 (4.0%) for Maori and 2047/51,921 (3.9%) for non-Maori, multivariable odds ratio (95%CI) 0.85 (0.73-0.99), p = 0.04. Maori spent on average (95%CI) 1.1 (0.5-1.7) fewer days alive and out of hospital than non-Maori, p < 0.001. In conclusion, our patients experienced improving postoperative outcomes from 2004 to 2013, including the periods before and after implementation of the surgical checklist. Maori patients had worse outcomes than non-Maori.

Evaluating the ORSIM® simulator for assessment of anaesthetists' skills in flexible bronchoscopy: aspects of validity and reliability.

BACKGROUND: Developing expertise in flexible bronchoscopy is limited by inadequate opportunities to train on difficult airways. The new ORSIM bronchoscopy simulator aims to address this by creating virtual patients with difficult airways. This study aims to provide evidence on the validity and reliability of the ORSIM for assessment of subjects on both normal and abnormal airway simulations. METHODS: Novice, trainee, and expert subjects performed seven simulations of varying difficulty and scored the perceived difficulty for each. Time to completion was measured. Three blinded raters independently scored videos of each subject's performance. We measured inter-rater agreement and the difference in raters' scores between subject groups. RESULTS: We recruited 28 study subjects, generating 196 videos for analysis. Expert subjects consistently completed the scenarios faster than novices. Overall performance scores showed significant differences between subject groups (P<0.0001). Inter-rater reliability of scores was >0.8. CONCLUSIONS: Our results provide initial evidence on the validity and reliability of the ORSIM bronchoscopy simulator, supporting its potential value in training and assessment.

The impact of trained assistance on error rates in anaesthesia: a simulation-based randomised controlled trial.

Trained assistance for the anaesthetist appears likely to improve safety in anaesthesia. However, there are few objective data to support this assumption, and the requirement for a trained assistant is not universally enforced. We applied a simulation-based model developed in previous work to test the hypothesis that the presence of a trained assistant reduces error in anaesthesia. Ten randomly selected anaesthetists, five trained anaesthetic technicians and five theatre nurses without training in anaesthesia participated in two simulated emergencies, with anaesthetists working alternately with a technician or a nurse. The mean (SD) error rate per scenario was 4.75 (2.9). There were significantly fewer errors in the technician group than the nurse group (33 vs 62, p = 0.01) and this difference remained significant when errors were weighted for severity. This provides objective evidence supporting the requirement for trained assistance to the anaesthetist, and furthermore, demonstrates that a simulation-based model can provide rigorous evidence on safety interventions in anaesthesia.

A simulation design for research evaluating safety innovations in anaesthesia*.

SUMMARY: It is notoriously difficult to obtain evidence from clinical randomised controlled trials for safety innovations in healthcare. We have developed a research design using simulation for the evaluation of safety initiatives in anaesthesia. We used a standard and a modified scenario in a human-patient simulator, involving a potentially life-threatening problem requiring prompt attention--either a cardiac arrest or a failure in oxygen supply. The modified scenarios involved distractions such as loud music, a demanding and uncooperative surgeon, telephone calls and frequent questions from a medical student. Twenty anaesthetics were administered by 10 anaesthetists. A mean (SD) of 11.3 (2.8) errors per anaesthetic were identified in the oxygen failure scenarios, compared with 8.0 (3.4) in the cardiac arrest scenarios (ANOVA: p = 0.04). The difference between the combined standard scenarios and the combined modified scenarios was not significant. The mean rate of errors overall was 9.7 per simulation, with a pooled SD of 4.46, so in future studies 21 subjects would provide 80% statistical power to show a reduction in error rate of 30% from baseline with p

Fibromuscular hyperplasia of the internal carotid artery. A further cause of the 'moyamoya' collateral circulation.

Fibromuscular hyperplasia is a rare cause of internal carotid artery occlusion. We present a case where long stenoses of both internal carotid arteries were associated with terminal carotid occlusions and a ruptured basilar aneurysm.

Familial hyperuricemia and renal disease.

Information on a familial syndrome of hyperuricemia and renal disease with or without gout was obtained on 33 of 41 blood relatives: Nine had renal disease; abnormalities of the urinary sediments were minimal; serum uric acid levels were elevated in seven and were not measured in two. Hyperuricemia was noted in three additional family members without evidence of renal disease. Goulty arthritis (three patients) did not precede renal disease. One individual had hyperuricosuria. The following erythrocyte purine enzyme levels were normal: adenine phosphoribosyltransferase, hypoxanthine-guanine phosphoribosyltransferase, phosphoribosylpyrophosphate, synthetase, adenosine deaminiase, and purine nucleoside phosphorylase. Renal biopsy specimens showed focal global and segmental sclerosis of glomeruli, occasional hypercellularity, foci of atrophic tubules, chronic interstitial inflammation, and folding and wrinkling of glomerular basement membrane without electron-dense deposits. There were no immunofluorescent abnormalities.