The aim was to determine the mode of presentation and 30 day procedural risks in 4418 patients with 4743 carotid body tumours (CBTs) undergoing surgical excision.
This is a systematic review and ...meta-analysis of 104 observational studies.
Overall, 4418 patients with 4743 CBTs were identified. The mean age was 47 years, with the majority being female (65%). The commonest presentation was a neck mass (75%), of which 85% were painless. Dysphagia, cranial nerve injury (CNI), and headache were present in 3%, while virtually no one presented with a transient ischaemic attack (0.26%) or stroke (0.09%). The majority (97%) underwent excision, but only 21% underwent pre-operative embolisation. Overall, 27% were Shamblin I CBTs; 44% were Shamblin II; and 29% were Shamblin III. The mean 30 day mortality was 2.29% (95% CI 1.79–2.93). The mean 30 day stroke rate was 3.53% (95% CI 2.91–4.29), while the mean 30 day CNI rate was 25.4% (95% CI 24.5–31.22). The prevalence of persisting CNI at 30 days was 11.15% (95% CI 8.42–14.64). Twelve series (544 patients) correlated 30 day stroke with Shamblin status. Shamblin I CBTs were associated with a 1.89% stroke rate (95% CI 0.92–3.82), increasing to 2.71% (95% CI 1.43–5.07) for Shamblin II CBTs and 3.99% (95% CI 2.34–6.74) for Shamblin III tumours. Twenty-six series (1075 patients) correlated CNI rates with Shamblin status: 3.76% (95% CI 2.62–5.35) for Shamblin I CBTs, 14.14% (95% CI 11.94–16.68) for Shamblin II, and 17.10% (95% CI 14.82–19.65) for Shamblin III tumours. The prevalence of neck haematoma requiring re-exploration was 5.24% (95% CI 3.45–7.91). The proportion of patients with a neck haematoma requiring re-exploration was not reduced by pre-operative embolisation (5.92%; 95% CI 2.56–13.08) vs. no embolisation (5.82%; 95% CI 2.76–11.88). Pre-operative embolisation did not reduce drainage losses (639 mL vs. 653 mL).
This is the largest meta-analysis of outcomes after CBT excision. Procedural risks associated with tumour excision were considerable, especially with Shamblin III tumours where 4% suffered a peri-operative stroke and 17% suffered a CNI.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Despite level I evidence, no worldwide consensus of opinion exists on how best to manage patients with asymptomatic carotid artery disease. In this article, I present the evidence supporting ...intervention in these patients, highlighting a number of 'inconvenient truths' that challenge the current 'one size fits all' approach to treatment. I will demonstrate that, even if one could identify and treat every individual with a 60-99% asymptomatic stenosis, >95% of all strokes will still occur. Evidence shows that 94% of all carotid endarterectomy and carotid artery stenting procedures in asymptomatic patients in the US are ultimately unnecessary, costing health-care providers US$2 billion annually. Evidence also exists that the risk of stroke in patients treated medically is lower than when the asymptomatic trials were recruiting, challenging the appropriateness of basing contemporary guidelines upon historical data. A small cohort of 'high-risk for stroke' patients will undoubtedly benefit from intervention and our goal must be to identify and treat these individuals, rather than continuing with a policy of mass intervention that benefits very few patients in the long term.
The aim of this review was to carry out primary and secondary analyses of 20 randomised controlled trials (RCTs) comparing carotid endarterectomy (CEA) with carotid artery stenting (CAS).
A ...systematic review and meta-analysis of data from 20 RCTs (126 publications) was carried out.
Compared with CEA, the 30 day death/stroke rate was significantly higher after CAS in seven RCTs involving 3467 asymptomatic patients (odds ratio OR 1.64, 95% confidence interval CI 1.02–2.64) and in 10 RCTs involving 5797 symptomatic patients (OR 1.71, 95% CI 1.38–2.11). Excluding procedural risks, late ipsilateral stroke was about 4% at 9 years for both CEA and CAS, i.e., CAS was durable. Reducing procedural death/stroke after CAS may be achieved through better case selection, e.g., performing CEA in (i) symptomatic patients aged > 70 years; (ii) interventions within 14 days of symptom onset; and (iii) situations where stroke risk after CAS is predicted to be higher (segmental/remote plaques, plaque length > 13 mm, heavy burden of white matter lesions WMLs, where two or more stents might be needed). New WMLs were significantly more common after CAS (52% vs. 17%) and were associated with higher rates of late stroke/transient ischaemic attack (23% vs. 9%), but there was no evidence that new WMLs predisposed towards late cognitive impairment. Restenoses were more common after CAS (10%) but did not increase late ipsilateral stroke. Restenoses (70%–99%) after CEA were associated with a small but significant increase in late ipsilateral stroke (OR 3.87, 95% CI 1.96–7.67; p < .001).
CAS confers higher rates of 30 day death/stroke than CEA. After 30 days, ipsilateral stroke is virtually identical for CEA and CAS. Key issues to be resolved include the following: (i) Will newer stent technologies and improved cerebral protection allow CAS to be performed < 14 days after symptom onset with risks similar to CEA? (ii) What is the optimal volume of CAS procedures to maintain competency? (iii) How to deliver better risk factor control and best medical treatment? (iv) Is there a role for CEA/CAS in preventing/reversing cognitive impairment?
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multidisciplinary design optimization (MDO) is concerned with solving design problems involving coupled numerical models of complex engineering systems. While various MDO software frameworks exist, ...none of them take full advantage of state-of-the-art algorithms to solve coupled models efficiently. Furthermore, there is a need to facilitate the computation of the derivatives of these coupled models for use with gradient-based optimization algorithms to enable design with respect to large numbers of variables. In this paper, we present the theory and architecture of OpenMDAO, an open-source MDO framework that uses Newton-type algorithms to solve coupled systems and exploits problem structure through new hierarchical strategies to achieve high computational efficiency. OpenMDAO also provides a framework for computing coupled derivatives efficiently and in a way that exploits problem sparsity. We demonstrate the framework’s efficiency by benchmarking scalable test problems. We also summarize a number of OpenMDAO applications previously reported in the literature, which include trajectory optimization, wing design, and structural topology optimization, demonstrating that the framework is effective in both coupling existing models and developing new multidisciplinary models from the ground up. Given the potential of the OpenMDAO framework, we expect the number of users and developers to continue growing, enabling even more diverse applications in engineering analysis and design.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
