Measurement of upper limb function in ALS: a structured review of current methods and future directions.

Measurement of upper limb function is critical for tracking clinical severity in amyotrophic lateral sclerosis (ALS). The Amyotrophic Lateral Sclerosis Rating Scale-revised (ALSFRS-r) is the primary outcome measure utilised in clinical trials and research in ALS. This scale is limited by floor and ceiling effects within subscales, such that clinically meaningful changes for subjects are often missed, impacting upon the evaluation of new drugs and treatments. Technology has the potential to provide sensitive, objective outcome measurement. This paper is a structured review of current methods and future trends in the measurement of upper limb function with a particular focus on ALS. Technologies that have the potential to radically change the upper limb measurement field and explore the limitations of current technological sensors and solutions in terms of costs and user suitability are discussed. The field is expanding but there remains an unmet need for simple, sensitive and clinically meaningful tests of upper limb function in ALS along with identifying consensus on the direction technology must take to meet this need.

High-flow Nasal Cannulae, Bronchopulmonary Dysplasia and Retinopathy of Prematurity

Aims To determine if HFNC use was associated with changes in incidence of BPD and ROP. Methods This retrospective study examined premature infants (<30 weeks GA or <1500g) in a tertiary neonatal unit from 2010- 2016. Patients were compared before and after introduction of HFNC. Further analysis of high-risk infants (<28 weeks GA or <750g or ventilated) compared those who received HFNC to those who did not across the whole period. Primary outcomes were incidence of BPD and ROP requiring surgery. Results Incidence of BPD rose following the introduction of HFNC (82/232 (35.3%) after vs 33/251 (13.1%) before, p<0.001). On multivariate analysis, the chance of developing BPD after HFNC introduction remained higher (OR 4.353, 95% CI 2.546-7.443). More infants received surgery for ROP following HFNC introduction (0/214 vs 11/205 (5.4%), p=<0.001). In the second analysis, the rate of BPD was higher in those who received HFNC (90/132 (68.1%) vs 33/153 (21.6%), p<0.001). Receiving HFNC demonstrated higher chance of BPD in multivariate analysis (OR 7.802, 95% CI 4.223-14.423). Rate of ROP surgery was higher in those who received HFNC (0/153 vs 13/134 (9.7%), p<0.001). Conclusions In this study, use of HFNC was associated with significantly increased risk of adverse outcomes.

Collagen fibre orientation and dispersion govern ultimate tensile strength, stiffness and the fatigue performance of bovine pericardium.

The durability of bovine pericardium leaflets employed in bioprosthetic heart valves (BHVs) can significantly limit the longevity of heart valve prostheses. Collagen fibres are the dominant load bearing component of bovine pericardium, however fibre architecture within leaflet geometries is not explicitly controlled in the manufacture of commercial devices. Thus, the purpose of this study was to ascertain the influence of pre-determined collagen fibre orientation and dispersion on the mechanical performance of bovine pericardium. Three tissue groups were tested in uniaxial tension: cross-fibre tissue (XD); highly dispersed fibre-orientations (HD); or preferred-fibre tissue (PD). Both the XD and PD tissue were tested under cyclic loading at 1.5 Hz and a stress range of 2.7 MPa. The results of the static tensile experiments illustrated that collagen fibre orientation and degree of alignment significantly influenced the material's response, whereby, there was a statistically significant decrease in material properties between the XD groups and both the PD and HD groups for ultimate tensile strength and stiffness (p < 0.01). Furthermore, HD tissue had a stiffness of approximately 58% of the PD group, and XD tissue had a stiffness of approximately 18% of the PD group. The dynamic behaviour of the XD and PD groups was extremely distinct; for example a Weibull analysis indicated that the 50% probability of failure in specimens with fibres orientated perpendicular (XD) to the loading direction occurred at 375 cycles. Due to this failure, XD specimens survived on average less than 20% of the cycles completed by those in which fibres were aligned along the loading direction (PD). The results from this study indicate that fibre architecture is a significant factor in determining static strength and fatigue life in bovine pericardium, and thus must be incorporated in the design process to improve future device durability.

The impact of older age on patient outcomes following primary total knee arthroplasty.

AIMS: As the population ages, there is projected to be an increase in the level of demand for total knee arthroplasty (TKA) in octogenarians. We aimed to explore whether those aged ≥ 80 years achieved similar improvements in physical function to younger patients while also comparing the rates of length of stay (LOS), discharge to rehabilitation, postoperative complications, and mortality following TKA in older and younger patients. PATIENTS AND METHODS: Patients from one institution who underwent primary elective TKA between 1 January 2006 and 31 December 2014 were dichotomized into those ≥ 80 years old (n = 359) and those < 80 years old (n = 2479) for comparison. Multivariable regression was used to compare the physical status component of the 12-Item Short-Form Health Survey (SF-12), LOS, discharge to rehabilitation, complications, and mortality between the two groups. RESULTS: Both age groups demonstrated a clinically meaningful improvement in their self-reported physical health relative to their baseline with no clinically relevant difference noted between them. Being ≥ 80 years old was associated with a 0.58-day increase in LOS and older patients were more likely to be discharged to rehabilitation (odds ratio (OR) 3.06, p < 0.001). Medical complications and mortality were higher in elderly patients (OR 1.92 for complications, p < 0.001; hazard ratio 3.40 for death, p < 0.001). There was no statistically significant association between age group and experiencing a postoperative surgical or wound-related complication. CONCLUSION: Those aged over 80 years achieved a statistically significant lower median SF-12 physical score than the younger group, after adjusting for the preoperative score, but this difference of 4.46 was not considered to be clinically meaningful. However, clinicians should be aware that the elderly are at a higher risk of experiencing longer hospital stays, postoperative medical complications, and mortality. Cite this article: Bone Joint J 2018;100-B:1463-70.

Olanzapine or chlorpromazine plus lithium in first episode psychotic mania: An 8-week randomised controlled trial.

BACKGROUND: Treatment strategies for mental disorders may vary according to illness stage. However no data currently exist to guide treatment in first episode psychotic mania. The aim of this study was to compare the safety and efficacy profile of chlorpromazine and olanzapine, as add-on to lithium, in patients with a first episode of psychotic mania, expecting better safety profile and adherence to olanzapine but similar efficacy for both treatments. METHODS: Data from 83 patients were collected in an 8-week randomised controlled trial on clinical variables, side effects, vital signs, and weight. Analyses of treatment differences over time were based on intent-to-treat principles. Kaplan-Meier estimated survival curves were used to analyse time-to-event data and mixed effects models repeated measures analysis of variance were used to determine treatment group differences over time on safety and efficacy measures. RESULTS: Ethics committee approval to delay informed consent procedure until recovery from the acute episode allowed the inclusion of 83 patients highly representative of those treated in the public sector. Contrary to our hypotheses, safety profile of both medications was similar. A signal for higher rate (P=.032) and earlier occurrence (P=.043) of mania remission was observed in the olanzapine group which did not survive correction for multiple comparisons. CONCLUSIONS: Olanzapine and chlorpromazine have a similar safety profile in a uniquely representative cohort of patients with first episode psychotic mania. The possibility for a greater impact of olanzapine on manic symptoms leading to earlier remission of the episode needs exploration in a large sample.

An experimental study to determine the optimal access route for renal artery interventions.

OBJECTIVE: The standard approach for endovascular treatment of the renal artery is access via the common femoral artery. However, approximately one in eight patients have a renal artery take-off angle that is less than 50°. In these patients approaching via a femoral access site can be technically challenging. The goal of this study was to design and implement a set of experiments that could empirically determine the critical renal artery take-off angle at which a superior approach would be employed. METHODS: An experimental model of the abdominal aorta, iliac arteries and the renal arteries was constructed using averaged CT angiography data from 10 patients. A number of guide catheter and guide wire combinations were advanced into this model and the force/displacement response was established. RESULTS: Our results demonstrate that a renal artery take-off angle less than 30° has a reduced probability of achieving stable guide wire placement in comparison with the base 90° anatomy (p ≤ .0001). Additionally, our results indicate that the probability of achieving stable guide wire access is increased if the stiffness mismatch between the guide catheter and guide wire is minimised. CONCLUSIONS: In conclusion, we recommend a superior approach to the renal artery if the renal artery take-off angle is within the range of 33-38° and a stiff guide wire platform (e.g. an Amplatz stiff) is required to complete the procedure. Finally, we report an equation that can be used to determine the difficulty associated with accessing the renal artery in comparison to the base 90° anatomy.

Coping strategies in carers of young people with a first episode of psychosis.

BACKGROUND: Carers of young people with first episode psychosis (FEP) often face burden. Understanding ways in which carers cope is not only important for providing support to them but might maximise patient outcomes. The aim of this study was to examine strategies carers use to cope with the burden of caring for a young person with FEP. METHODS: The study was part of a randomized controlled trial focusing on the effectiveness of a problem-solving bibliotherapy intervention for carers of FEP patients, in terms of promoting coping and reducing psychological distress. Baseline data on the Ways of Coping (WOC) scale was available for 124 carers aged between 18 and 66 years. Principal component analysis with PROMAX rotation was used to determine the number of factors that could be used to characterise coping behaviour. Regression analyses were used to determine how the factors were related to carers' demographics, burden, psychological well-being and expressed emotion. RESULTS: Approximately half of the carers reported that they frequently use positive coping techniques such as self-talk, active problem solving, and positive reframing. The factor analysis yielded five factors: (i) cognitive-escape coping; (ii) optimistic coping; (iii) seeking connections; (iv) tension reduction; and (v) distancing. The relationships between these factors and demographic characteristics, carers' perception of burden, expressed emotion, and psychological distress are reported. CONCLUSIONS: Avoidance coping strategies are related to psychological distress, emotional over-involvement, and increased carer burden. Interventions facilitating the use of adaptive problem solving and positive re-appraisal will promote carer coping and reduce psychological distress.

Investigating the feasibility of using a grit blasting process to coat nitinol stents with hydroxyapatite.

This study investigates the feasibility of utilising a grit blasting process to coat three nitinol substrates (a planer 2D surface, a circular wire and a cardiovascular stent geometry) with a hydroxyapatite coating. Surface characteristics of the coating on the three substrates were determined and additionally the durability of the coating post fatigue testing was analysed. The coating process resulted in a consistent covering of the substrate that resulted in an extremely hydrophilic stent surface. The surface roughness was dependant on grit blasting particle size. A general trend of smaller particle size resulted in a lower surface roughness, while particle size did not have an effect on the hydroxyapatite coating thickness. Fatigue integrity tests that simulated 16 months implantation demonstrated minimal damage to the coating. In conclusion we demonstrated the initial feasibility of using a grit blasting method to produce a consistent, hydrophilic, and durable HAp stent coating that has the capability of incorporating a drug eluting function.

Current evidence for human yersiniosis in Ireland.

Yersiniosis associated with abdominal pain was commonly reported in Ireland in the 1980s. However, the Health Protection Surveillance Centre (HPSC) currently records only three to seven notified cases of yersiniosis per year. The most common cause of yersiniosis worldwide is Yersinia enterocolitica, and the leading source for this organism is consumption of pork-based food products. In contrast to the apparent current scarcity of yersiniosis cases in humans in Ireland, pathogenic Y. enterocolitica are detectable in a high percentages of pigs. To establish whether the small number of notifications of human disease was an underestimate due to lack of specific selective culture for Yersinia, we carried out a prospective culture study of faecal samples from outpatients with diarrhoea, with additional culture of throat swabs, appendix swabs and screening of human sewage. Pathogenic Yersinia strains were not isolated from 1,189 faeces samples, nor from 297 throat swabs, or 23 appendix swabs. This suggested that current low notification rates in Ireland are not due to the lack of specific Yersinia culture procedures. Molecular screening detected a wider variety of Y. enterocolitica-specific targets in pig slurry than in human sewage. A serological survey for antibodies against Yersinia YOP (Yersinia Outer Proteins) proteins in Irish blood donors found antibodies in 25 %, with an age-related trend to increased seropositivity, compatible with the hypothesis that yersiniosis may have been more prevalent in Ireland in the recent past.

Mechanical characterization of a customized decellularized scaffold for vascular tissue engineering.

Several challenges persist when attempting to utilize decellularized tissue as a scaffold for vascular tissue engineering. Namely: poor cell infiltration/migration, excessive culture times associated with repopulating the scaffolds, and the achievement of a quiescent medial layer. In an attempt to create an optimum vascular scaffold, we customized the properties of decellularized porcine carotid arteries by: (i) creating cavities within the medial layer to allow direct injection of cells, and (ii) controlling the amount of collagen digestion to increase the porosity. Histological examination of our customized scaffold revealed a highly porous tissue structure containing consistent medial cavities running longitudinally through the porous scaffold wall. Mechanical testing of the customized scaffold showed that our minimal localized disruption to the ECM does not have a detrimental effect on the bulk mechanical response of the tissue. The results demonstrate that an increased stiffness and reduced distensibility occurs after decellularization when compared to the native tissue, however post scaffold customization we can revert the scaffold tensile properties back to that of the native tissue. This most noteworthy result occurs in the elastin dominant phase of the tensile response of the scaffold, indicating that no disruption has occurred to the elastin network by our decellularization and customization techniques. Additionally, the bulk seeding potential of the customized scaffold was demonstrated by direct injection of human smooth muscle cells through the medial cavities. The optimum cell dispersion was observed in the highest porosity scaffold, with large cell numbers retained within the medial layer after 24 h static culture. In summary, this study presents a novel customized decellularized vascular scaffold that has the capability of bulk seeding the media, and in tandem to this method, the porosity of the scaffold has been increased without compromising the mechanical integrity.

Introducing random safety audits (RSA) in a neonatal intensive care unit (NICU).

Random safety audits (RSA) have been shown to be effective in improving standards of clinical practice. 19 data collection audits were performed relating to hygiene, safe prescribing, oxygen pulse oximetry monitoring and documentation in keeping with the requirements of the new Medical Practitioners Act (MPA) 2007. Hygiene audits (range from 20/25 to 21/21 80%-100%) and safe prescribing audits (range from 23/25 to 25/25 86%-100%) achieved n=25 100% compliance with unit guidelines over a 3 month period. Compliance with oxygen pulse oximetry monitoring guideline limits improved from 4/27 (15%) to 9/16 (56%). Compliance with requirement and use of Physician IMC registration number in documentation was only 10/18 (56%). RSA's led to improvements in hygiene and prescribing. Compliance with oxygen monitoring guideline limits highlighted the need for greater education. Awareness of legal requirements relating to documentation improved but this has not translated into a change in practice. RSA's can facilitate real time quality improvement in daily clinical practice.

Are the eucalypt and non-eucalypt components of Australian tropical savannas independent?

Eucalypts (Eucalyptus and Corymbia spp.) dominate (>60%) the tree biomass of Australia's tropical savannas but account for only a fraction (28%) of the tree diversity. Because of their considerable biomass and adaptation to environmental stressors, such as fire, the eucalypts may drive tree dynamics in these savannas, possibly to the exclusion of non-eucalypts. We evaluated whether the eucalypt and non-eucalypt components in tropical savannas are dependent so that changes in one component are matched by opposite trends in the other. Using tree inventory data from 127 savanna sites across the rainfall and fire frequency gradients, we found that eucalypt and non-eucalypt basal area and species richness had a negative relationship. This relationship was maintained across the rainfall gradient, with rainfall having a positive effect on the basal area and species richness of both components, but with a greater effect in non-eucalypts. Fire frequency negatively affected basal area, but not species richness, although basal area and species richness of eucalypts and non-eucalypts did not differ in their response to fire. Rainfall appears to set the upper bounds to woody biomass in these mesic savannas, while fire maintains woody biomass below carrying capacity and facilitates coexistence of the components. The magnitude of the component responses, particularly for non-eucalypts, is determined by rainfall, but their dependence is likely due to their differential response to both rainfall and fire, but not to competition for resources. Thus, while eucalypts dominate biomass overall, at high rainfall sites non-eucalypt basal area and diversity are highest, especially where fire frequency is low.

Palivizumab use in preterm neonates.

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis in infants. Palivizumab is an immunoprophylactic agent for RSV prevention in preterm infants and those with neonatal chronic lung disease. This study examines its use across neonatal units in Ireland. A questionnaire was administered to one Consultant Neonatologist or Paediatrician in each of the 20 maternity centres in Ireland about their guidelines for Palivizumab administration. There is variation in administration of Palivizumab with little consistency found between protocols reported in terms of age and presence of chronic lung disease. Ten centres have in house protocols, 3 centres use the American Academy of Paediatrics (AAP) guidelines, 2 centres prefer the UK Joint Committee on Vaccination and Immunisation (JCVI) guidelines and 3 centres do not have a set protocol. Four participants felt its use has impacted on hospital admissions and 61% believe its use is cost effective. The budgetary implication for immunoprophylaxis with Palivizumab in Ireland is estimated at 1.5 to 2 million euros annually. Given current pharmacoeconomic constraints there is a need to implement a national protocol on RSV immunoprophylaxis.

Benchmarking care for very low birthweight infants in Ireland and Northern Ireland.

BACKGROUND: Benchmarking is that process through which best practice is identified and continuous quality improvement pursued through comparison and sharing. The Vermont Oxford Neonatal Network (VON) is the largest international external reference centre for very low birth weight (VLBW) infants. This report from 2004-7 compares survival and morbidity throughout Ireland and benchmarks these results against VON. METHODS: A standardised VON database for VLBW infants was created in 14 participating centres across Ireland and Northern Ireland. RESULTS: Data on 716 babies were submitted in 2004, increasing to 796 babies in 2007, with centres caring for from 10 to 120 VLBW infants per year. In 2007, mortality rates in VLBW infants varied from 4% to 19%. Standardised mortality ratios indicate that the number of deaths observed was not significantly different from the number expected, based on the characteristics of infants treated. There was no difference in the incidence of severe intraventricular haemorrhage between all-Ireland and VON groups (5% vs 6%, respectively). All-Ireland rates for chronic lung disease (CLD; 15-21%) remained lower than rates seen in the VON group (24-28%). The rates of late onset nosocomial infection in the all-Ireland group (25-26%) remained double those in the VON group (12-13%). DISCUSSION: This is the first all-Ireland international benchmarking report in any medical specialty. Survival, severe intraventricular haemorrhage and CLD compare favourably with international standards, but rates of nosocomial infection in neonatal units are concerning. Benchmarking clinical outcomes is critical for quality improvement and informing decisions concerning neonatal intensive care service provision.

Characterization of Staphylococcus aureus isolated from dairy animals in Ireland.

Enterotoxigenic Staphylococcus aureus frequently contaminate milk and milk products causing food poisoning. Staphylococcus aureus were isolated from bovine, ovine and caprine milk and milk filters from 78 dairy production holdings supplying the farmhouse cheese sector in Ireland, using standard culture methods. Molecular methods were applied to study the distribution of genes encoding staphylococcal enterotoxins and toxic shock syndrome toxin in the collection. Multilocus variable number tandem repeat analysis was used to subtype the collection. One hundred and two Staphylococcus aureus (54 milk filters and 48 bulk milk) were recovered from apparently healthy animals; half of the isolates were toxigenic. Our findings are discussed in light of the risks posed to public health.

Defining the gap between electrographic seizure burden, clinical expression and staff recognition of neonatal seizures.

BACKGROUND: Neonatal seizures are often subclinical, making accurate diagnosis difficult. OBJECTIVE: To describe the clinical manifestations of electrographic seizures recorded on continuous video-EEG, and to compare this description with the recognition of clinical seizures by experienced neonatal staff. METHODS: Term infants, at risk of seizures, were monitored by continuous 12-channel video-EEG from <6 hours of birth for up to 72 hours. All clinical seizures were recorded by experienced neonatal staff on individual seizure charts. Video-EEG recordings were subsequently analysed. The number, duration and clinical expression of electrographic seizures were calculated (in seconds), and compared with the seizures clinically suspected by the neonatal staff. RESULTS: Of 51 infants enrolled, nine had electrographic seizures. A further three had clinically suspected seizures, without associated electrographic abnormality. Of the total 526 electrographic seizures, 179 (34%) had clinical manifestations evident on the simultaneous video recording. The clinical seizure activity corresponded to 18.8% of the total electrographic seizure burden. Overdiagnosis also occurred frequently. Of the 177 clinically suspected seizure episodes documented by staff, 48 (27%) had corresponding electrographic evidence of seizure activity Thus, only 9% (48/526) of electrographic seizures were accompanied by clinical manifestations, which were identified and documented by neonatal staff. CONCLUSION: Only one-third of neonatal EEG seizures displays clinical signs on simultaneous video recordings. Moreover, two-thirds of these clinical manifestations are unrecognised, or misinterpreted by experienced neonatal staff. In the recognition and management of neonatal seizures clinical diagnosis alone is not enough.

Persistent lactic acidosis in neonatal hypoxic-ischaemic encephalopathy correlates with EEG grade and electrographic seizure burden.

BACKGROUND: Predicting at birth which infants with perinatal hypoxic-ischaemic injury will progress to significant encephalopathy remains a challenge. OBJECTIVE: To determine whether lactic acidosis at birth in asphyxiated neonates could predict the grade of EEG encephalopathy by examining the relationship between time taken for the normalisation of lactate, severity of encephalopathy and seizure burden. METHODS: Continuous early video-EEG monitoring was performed in babies at risk for hypoxic-ischaemic encephalopathy. Encephalopathy was graded from the EEG data. Total seizure burden (seconds) was calculated for each baby. Initial blood gas measurements of pH, base deficit and lactate were taken within 30 minutes of delivery. Time to normal serum lactate was determined in hours from birth for each infant. RESULTS: All 50 term infants had raised initial serum lactate (median (lower, upper quartiles) 11.7 (10.2, 14.9)). There were no significant differences between the initial serum lactate, pH and base deficit in infants with normal/mildly abnormal (n = 24), moderately abnormal (n = 14), severely abnormal (n = 5) and inactive EEGs (n = 7). Time to normal lactate varied significantly with EEG grade (median (lower, upper quartile) 6.0 (4.1, 9.5) for mild/normal EEG, 13.5 (6.8, 23.5) moderate EEG, 41.5 (30.0, 55.5) severe group, 12.0 (8.1, 21.5) inactive group; p<0.001). Time to normal lactate correlated significantly with EEG seizure burden (seconds; R = 0.446, p = 0.002). Mean (SD) time to normal lactate was 10.0 (7.2) hours in infants who did not have seizures and 27.3 (19.0) hours in the 13 infants with electrographic seizures (p = 0.002). CONCLUSIONS: Serum lactate levels in the first 30 minutes of life do not predict the severity of the ensuing encephalopathy. In contrast, sustained lactic acidosis is associated with severe encephalopathy on EEG and correlates with seizure burden.

Have we stopped looking for a red reflex in newborn screening?

Best medical evidence indicates that surgical treatment of significant congenital cataracts is required within the first 3 months of life for optimal visual outcome. The aim of the present study was to review when the diagnosis of congenital cataracts was made in our region, by whom it was made, and the visual outcome at 2 years of age or more. This was a retrospective study in a region with a population of 546,000 and approximately 8500 births per annum, served by a single Regional Ophthalmology centre. All children under 15 years, diagnosed with Congenital Cataract over a 10-year period (1991-2002), were identified using the Hospital In-Patient Enquiry [HIPE] database. Children with cataract(s) from infancy from a congenital cause and those first presenting outside infancy but with salient clinical features indicating early cataract were included in the study. 27 cases of congenital and infantile cataract 15 (56%) males, 12 (44%) females were retrieved. 17 infants (63%) were diagnosed with bilateral disease, while the remainder were unilateral 10 (37%). Most of the cases 17 (63%) were diagnosed following presentation with parental/carer concerns about visual function (usually a squint). However only 2 of these 17 cases presented before 3 months of age. The remaining cases of congenital cataracts were diagnosed by general practitioners 8 (24%), paediatricians 4 (12%), ophthalmologists 3 (9%) or School Medical Officer (1, 3%). No case of congenital cataract was diagnosed by newborn screening examination. Six of 8 infants diagnosed with congenital cataracts before three months of age had a good visual outcome, (visual acuity < 6/24 at 2 years or more). In contrast only 3 of 19 cases who were diagnosed after 3 months of age had good visual outcomes. Despite their relative rarity, it is imperative that congenital cataracts are diagnosed and treated within 3 months of birth. The onus of diagnosis rests with newborn screening examiners at birth and with general practitioners at the 6-8 week checks. Parental concerns about a possible squint should be addressed by performing a red light reflex examination and urgent specialist ophthalmological referral if a flaw is detected.

The influence of grain size on the ductility of micro-scale stainless steel stent struts.

Vascular stents are used to restore blood flow in stenotic arteries, and at present the implantation of a stent is the preferred revascularisation method for treating coronary artery disease, as the introduction of drug eluting stents (DESs) has lead to a significant improvement in the clinical outcome of coronary stenting. However the mechanical limits of stents are being tested when they are deployed in severe cases. In this study we aimed to show (by a combination of experimental tests and crystal plasticity finite element models) that the ductility of stainless steel stent struts can be increased by optimising the grain structure within micro-scale stainless steel stent struts. The results of the study show that within the specimen size range 55 to 190 microm ductility was not dependent on the size of the stent strut when the grain size maximised. For values of the ratio of cross sectional area to characteristic grain length less than 1,000, ductility was at a minimum irrespective of specimen size. However, when the ratio of cross sectional area to characteristic grain length becomes greater than 1,000 an improvement in ductility occurs, reaching a plateau when the ratio approaches a value characteristic of bulk material properties. In conclusion the ductility of micro-scale stainless steel stent struts is sensitive to microstructure and can be improved by reducing the grain size.