Explore the vast range of titles available.

The NHS abdominal aortic aneurysm (AAA) screening programme (NAAASP) is both clinically and economically effective. One of the main determinants of this effectiveness is disease prevalence. AAA prevalence is decreasing over time, steadily reducing the efficiency of the current NAAASP screening policy. One alternative to whole population screening is targeted screening of high-risk groups. Whether this would detect a clinically and publicly acceptable proportion of disease, and whether it would improve cost-effectiveness are unknown. The aim of this research is to estimate the clinical outcomes and cost-effectiveness of targeted AAA screening. Rather than conducting an expensive and time-consuming randomized trial to directly test targeted screening, we will undertake in-silico trials of targeted AAA screening. To determine success criteria for in-silico trials, the ethics and issues around the acceptability of targeted screening will first be explored through focus groups and interviews. A qualitative evidence synthesis to identify issues associated with targeted screening will be used to establish themes and topic guides. To perform the in-silico trials, individual men's outcomes from the NAAASP (2013-2024, ≈ 2,500,000 men, ≈ 1% with AAA) will be linked to primary care data from the Clinical Practice Research Datalink (CPRD) (20% overlap of records). Risk factors for AAA will be identified by developing a risk prediction model and used as targeted screening criteria in in-silico trials, with diagnostic accuracy as the primary outcome. A discrete event simulation model will be adopted to extrapolate the trial findings beyond the observed period. We will estimate the clinical and cost-effectiveness of targeted screening compared with the current whole population screening strategy. Data linkage will be undertaken under Health Research Authority Confidentiality Advisory Group (Section 251) approval. Linked data will be effectively anonymised. Participants in the qualitative substudy will provide informed consent for participation. We expect this project to have a direct and significant impact on NHS, UK and worldwide AAA screening policies. The study findings will be submitted for publication in peer-reviewed journals and presented at scientific meetings.

The ability to discriminate between normal and impaired dynamic cerebral autoregulation (CA), based on measurements of spontaneous fluctuations in arterial blood pressure (BP) and cerebral blood flow (CBF), has considerable clinical relevance. We studied 45 normal subjects at rest and under hypercapnia induced by breathing a mixture of carbon dioxide and air. Non-linear models with BP as input and CBF velocity (CBFV) as output, were implemented with support vector machines (SVM) using separate recordings for learning and validation. Dynamic SVM implementations used either moving average or autoregressive structures. The efficiency of dynamic CA was estimated from the model's derived CBFV response to a step change in BP as an autoregulation index for both linear and non-linear models. Non-linear models with recurrences (autoregressive) showed the best results, with CA indexes of 5.9 ± 1.5 in normocapnia, and 2.5 ± 1.2 for hypercapnia with an area under the receiver-operator curve of 0.955. The high performance achieved by non-linear SVM models to detect deterioration of dynamic CA should encourage further assessment of its applicability to clinical conditions where CA might be impaired.

Although the assessment of dynamic cerebral autoregulation (CA) based on measurements of spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF) is a convenient and much used method, there remains uncertainty about its reliability. We tested the effects of increasing ABP variability, provoked by a modification of the thigh cuff method, on the ability of the autoregulation index to discriminate between normal and impaired CA, using hypercapnia as a surrogate for dynamic CA impairment. In 30 healthy volunteers, ABP (Finapres) and CBF velocity (CBFV, transcranial Doppler) were recorded at rest and during 5% CO2 breathing, with and without pseudo-random sequence inflation and deflation of bilateral thigh cuffs. The application of thigh cuffs increased ABP and CBFV variabilities and was not associated with a distortion of the CBFV step response estimates for both normocapnic and hypercapnic conditions (P = 0.59 and P = 0.96, respectively). Sensitivity and specificity of CA impairment detection were improved with the thigh cuff method, with the area under the receiver–operator curve increasing from 0.746 to 0.859 (P = 0.031). We conclude that the new method is a safe, efficient, and appealing alternative to currently existing assessment methods for the investigation of the status of CA.

Background Radiofrequency (RF) ablation has recently been expanded from palliative treatment into tissue-preserving surgery with controversial results. RF has been accused of septic complications and dysfunction of the target organ due to uncontrolled energy distribution. The aim of this study was to evaluate the short- and long-term implications of RF energy to the remaining splenic tissue after laparoscopic and open RF-assisted partial splenectomy. Methods Thirty pigs randomly underwent laparoscopic RF partial splenectomy ( n = 10), open RF partial splenectomy ( n = 10) using the Radionics Cooltip radiofrequency system (Tyco Hellas), while a third group ( n = 10) underwent the conventional procedure. Intraoperative parameters were recorded. Complete blood counts, along with splenic function tests, were estimated preoperatively, immediately postoperatively, and at 1 and 6 months after the procedure. Histology was also evaluated. A separate group of five animals randomly undergo conventional resection ( n = 2) and open RF resection ( n = 3). These animals were sacrificed 1 month postoperatively and were used for histology only. Results The blood loss was minimal in both RF groups. No septic complications were observed throughout the follow-up period. Laboratory values at 1 month postoperatively showed decreased splenic function in both RF groups. Histology at 1 month was indicative of a chronic inflammatory reaction to the RF groups whereas, in the control group, prominent hypervascular granulated tissue was observed. Six months postoperatively, the platelet count remained elevated in the RF groups. Histology revealed intense fibrosis at the ablation site, as opposed to friable granulated tissue in the conventional group. Conclusions Radiofrequency energy acts as an excellent haemostatic tool. The healing process shifts from the thermal injury to chronic inflammatory reaction and, 6 months later, to intense fibrosis as opposed to the hypervascular granulated tissue presented in the nonablated spleen. However, the longer the RF energy is applied, the more the splenic function is transiently affected.

Amyand’s hernia (AH) is characterized by the presence of the vermiform appendix in an inguinal hernia sac. Typically presenting on the right side and with manifestations similar to those seen in complicated hernias, it presents a diagnostic challenge and is frequently only diagnosed intraoperatively. We present the case of a left-sided AH on a 75-year-old man treated with appendicectomy, orchidectomy and hernioplasty without mesh.

Chylopericardium is a recognized complication of thoracic trauma, surgery or malignancy. Idiopathic or primary presentations, however, are rarely encountered in clinical practice. The severity of its presentation varies from the complete absence of symptoms to cardiac tamponade. We present the case of a 23-year-old woman with chylopericardium and extensive neck vein thrombosis that was managed surgically with a pericardial window.

Pseudoaneurysms of the popliteal artery are a rare clinical entity, accounting for <4% of all popliteal aneurysms. Accurate diagnosis and effective intervention is required to prevent potentially limb-threatening complications. We present the case of a 37-year-old man with acute limb ischaemia due to distal calf vessel thrombosis secondary to a popliteal pseudoaneurysm that was managed with covered stent placement and thrombolysis.