Comparison of Total Arch and Partial Arch Transposition During Hybrid Endovascular Repair for Aortic Arch Disease

OBJECTIVE

Total arch transposition (TAT) during hybrid endovascular repair for aortic arch disease is believed to allow a better landing zone, but also to be associated with higher peri-operative mortality than partial arch transposition (PAT). Information on this issue is limited.

METHOD

This study was a retrospective analysis. All 53 consecutive patients with aortic arch disease (41 males, mean age 65.0 years) who underwent hybrid endovascular repair with TAT (zone 0, n=20) or PAT (zone 1 or 2, n=33) from 2008 to 2014 were analyzed retrospectively. The peri-operative and late outcomes of these two groups were compared.

RESULTS

Baseline characteristics, including EuroSCORE II results, were similar in the two groups. After procedures, peri-operative mortalities and stroke rates were similar in the two groups (5.0% vs. 9.1%, p=1.000, and 10.0% vs. 6.1%, p=.627). Interestingly, all four strokes occurred in patients with a type III aortic arch irrespective of transposition type. Primary success rates (80.0% vs. 69.7%, p=.527) and type I endoleak incidences (20.0% vs. 27.3%, p=.744) were not significantly different. During follow up (mean duration 36.9 months), overall survival (89.7% vs. 87.4% at 1 year and 89.7% vs. 79.3% at 3 years; p=.375) and re-intervention free survival rates (78.6% vs. 92.0% at 1 year; 72.0% vs. 62.2% at 3 years, p=.872) were similar in the two groups.

CONCLUSION

Morbidity and mortality were high within the first year of hybrid endovascular therapy for aortic arch disease, implying that candidates for hybrid procedures need to be selected carefully. Hybrid endovascular repair with TAT was found to have peri-operative mortality, stroke, and long-term survival rates comparable with PAT, so hybrid endovascular repair may be considered, irrespective of type of arch reconstruction, when clinically indicated.

Outcomes in endoscopic sinus surgery: olfaction, nose scale and quality of life in a prospective cohort study

OBJECTIVES

To determine the efficacy of endoscopic sinus surgery (ESS) on olfactory function in chronic rhinosinusitis patients with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) and to compare the nasal obstruction and symptom evaluation (NOSE) scale before and after surgery.

DESIGN

A prospective cohort study SETTING: Royal National Throat and Nose and Ear Hospital, London UK.

PARTICIPANTS

One hundred and thirteen patients with CRS; 60 CRSwNP and 53 CRSsNP.

OUTCOME MEASUREMENTS

Olfaction was measured using both the University of Pennsylvania Smell Investigation Test (UPSIT) and the 'sense of smell' visual analogue scale (VAS). The NOSE scale, the sinonasal outcome test (SNOT 22) and the Lund-Kennedy (LK) surgeon reported scores were also measured pre- and postoperatively at 6 months.

RESULTS

The UPSIT psychophysical measurement significantly improved following ESS in the CRSwNP subgroup as did the patients perceived VAS sense of smell. However, in the CRSsNP subgroup, the improved VAS and UPSIT measurements were not significant. The NOSE, SNOT 22 and LK scores all improved significantly. The olfactory improvement as measured by the UPSIT correlated to the SNOT-22, but a correlation between the NOSE score and UPSIT was not found.

CONCLUSIONS

Endoscopic sinus surgery significantly improved the patient's perceived and measured sense of smell in the CRSwNP subgroup which is the most surgically responsive CRS subgroup. Additionally, improved olfaction in the CRSwNP subgroup is most likely to improve the patient's quality of life. Endoscopic sinus surgery significantly improved the NOSE scale in both CRS subgroups at 6 months following surgery.

Graphene oxide as a p-dopant and an anti-reflection coating layer, in graphene/silicon solar cells

It is shown that coating graphene-silicon (Gr/Si) Schottky junction based solar cells with graphene oxide (GO) improves the power conversion efficiency (PCE) of the cells, while demonstrating unprecedented device stability. The PCE has been shown to be increased to 10.6% (at incident radiation of 100 mW cm(-2)) for the Gr/Si solar cell with an optimal GO coating thickness compared to 3.6% for a bare/uncoated Gr/Si solar cell. The p-doping of graphene by the GO, which also serves as an antireflection coating (ARC) has been shown to be a main contributing factor to the enhanced PCE. A simple spin coating process has been used to apply GO with thickness commensurate with an anti-refection coating (ARC) and indicates the suitability of the developed methodology for large-scale solar cell assembly.

Exercise capacity independently predicts bone mineral density and proximal femoral geometry in patients with acute decompensated heart failure

Heart failure is associated with increased risk of osteoporosis. We evaluated the prevalence and predictors of osteoporosis in hospitalized patients with ADHF using quantitative computed tomography. Osteoporosis and vertebral fracture are prevalent in patients with ADHF and exercise capacity independently predicts bone mass and femoral bone geometry.

INTRODUCTION

Heart failure is associated with reduced bone mass and increased risk of osteoporotic fractures. However, the prevalence and predictors of osteoporosis in hospitalized patients with acute decompensated heart failure (ADHF) are not well understood.

METHODS

Sixty-five patients (15 postmenopausal females and 50 males) with ADHF were prospectively and consecutively enrolled. After stabilization of heart failure symptoms, quantitative computed tomography for bone mineral density (BMD) and femoral geometry as well as biochemical, echocardiographic, and cardiopulmonary exercise tests were performed.

RESULTS

Fifteen postmenopausal female showed a high prevalence of osteoporosis (40%) and vertebral fracture (53%). Among 50 male patients, 12% had osteoporosis and 32% had osteopenia, while vertebral fracture was found in 12%. Lumbar volumetric BMD (vBMD) was significantly lower in ischemic patients than non-ischemic patients (107.9 ± 47.5 vs. 145.4 ± 40.9 mg/cm(3), p = 0.005) in male. Exercise capacity, indicated by peak oxygen consumption (VO2), was significantly associated with lumbar vBMD (r = 0.576, p < 0.001) and total hip areal BMD (aBMD) (r = 0.512, p = 0.001) and cortical thickness of the femur neck (r = 0.544, p = 0.001). When controlled for age, body mass index, N-terminal proBrain natriuretic protein (NT-proBNP), etiology of heart failure, hemoglobin, and thigh circumference, multivariate regression analysis revealed peak VO2 independently predicted lumbar vBMD (β = 0.448, p = 0.031), total hip aBMD (β = 0.547, p = 0.021), and cortical thickness of the femur neck (β = 0.590, p = 0.011).

CONCLUSION

In male patients with ADHF, osteoporosis and vertebral fracture are prevalent, and exercise capacity independently predicts bone mass and geometry. Given that heart failure patients with reduced exercise capacity carry a substantial increased risk of fracture, proper osteoporosis evaluation is important in these patients.

Differentiation of solid-type serous cystic neoplasm from neuroendocrine tumour in the pancreas: value of abdominal MRI with diffusion-weighted imaging in comparison with MDCT

AIM

To evaluate the value of abdominal MRI with diffusion-weighted (DW) imaging for differentiation of solid-type serous cystic neoplasm (SCN) from neuroendocrine tumour (NET) in the pancreas compared with that of CT.

MATERIALS AND METHODS

Ten solid-type SCNs and 15 NETs were included in the study. Qualitative and quantitative analyses were performed, and two observers independently reviewed CT and MRI images for diagnosis of solid-type SCNs. Fisher's exact test and Mann-Whitney U-test, diagnostic performance [receiver operating characteristic (ROC) curve analysis] were evaluated.

RESULTS

SCNs showed more frequently hypo-attenuation on unenhanced CT images and marked hyperintensity on T2-weighted images compared with NETs (p < 0.01). The density of the tumour on unenhanced CT images and the apparent diffusion coefficient (ADC) value of the tumour were significantly different between SCNs (mean 18.5 HU; mean 2.45 × 10(-3) mm(2)/s) and NETs (mean 39.2 HU; mean 1.51 × 10(-3) mm(2)/s; p < 0.001). In the differentiation of SCNs from NETs, diagnostic performance of MRI with DW images was significantly higher than that of CT imaging (p < 0.01).

CONCLUSION

Abdominal DW-MRI shows a higher diagnostic accuracy than abdominal CT imaging in the differentiation of solid-type SCNs from NETs.

Mapping the nonlinear dynamics of a laser diode via its terminal voltage

We show that the bifurcations between dynamical states originating in the nonlinear dynamics of an external-cavity semiconductor laser at constant current can be detected by its terminal voltage V. We experimentally vary the intensity fed back into the gain medium by the external cavity and show that the dc component V(dc) of V tracks the optical intensity-based bifurcation diagram. It is shown using computational results based upon the Lang-Kobayashi model that whereas optical intensity accesses the dynamical-state variable |E|, V is related to population-inversion carrier density N. The change in feedback strength affects N and thereby the quasi-Fermi energy level difference at the p-i-n junction band-gap of the gain medium. The change in the quasi-Fermi energy-level thereby changes the terminal voltage V. Thus V is shown to provide information on the change in the dynamical-state variable N, which complements the more conventionally probed optical intensity.

Upper abdominal gadoxetic acid-enhanced and diffusion-weighted MRI for the detection of gastric cancer: Comparison with two-dimensional multidetector row CT

AIM

To evaluate the diagnostic performance of abdominal magnetic resonance imaging (MRI) for the detection of gastric cancer in comparison with that of two-dimensional (2D) multidetector row computed tomography (CT).

MATERIALS AND METHODS

The study included 189 patients with 170 surgically confirmed gastric cancers and 19 patients without gastric cancer, all of whom underwent gadoxetic acid-enhanced MRI with diffusion-weighted (DW) imaging, and multidetector contrast-enhanced abdominal CT imaging. Two observers independently analysed three sets of images (CT set, conventional MRI set, and combined conventional and DW MRI set). A five-point scale for likelihood of gastric cancer was used. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. Quantitative [apparent diffusion coefficient (ADC) analyses with Mann-Whitney U-test were conducted for gastric cancers and the nearby normal gastric wall.

RESULTS

The diagnostic accuracy and sensitivity for detection of gastric cancer were significantly higher on combined conventional and DW MRI set (77.8-78.3%; 75.3-75.9%) than the CT imaging set (67.7-71.4%; 64.1-68.2%) or the conventional MRI set (72-73%; 68.8-70%; p < 0.01). In particular, for gastric cancers with pT2 and pT3, the combined conventional and DW MRI set (91.6-92.6%) yielded significantly higher sensitivity for detection of gastric cancer than did the CT imaging set (76.8-81.1%) by both observers (p < 0.01). The mean ADC of gastric cancer lesions (1 ± 0.23 × 10(-3) mm(2)/s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10(-3) mm(2)/s; p < 0.01).

CONCLUSION

Abdominal MRI with DW imaging was more sensitive for the detection of gastric cancer than 2D-multidetector row CT or conventional MRI alone.

Pancreatic ductal adenocarcinoma: prevalence and diagnostic value of dark choledochal ring sign on T2-weighted MRI

AIM

To investigate the dark choledochal ring sign on T2-weighted imaging (T2WI) as an indicator for pancreatic ductal adenocarcinoma (PDAC) among periampullary carcinomas.

MATERIALS AND METHODS

Sixty patients with surgically confirmed periampullary cancers [30 PDACs, 15 distal common bile duct (CBD) cancers, 13 ampullary cancers, and two duodenal cancers] who underwent liver magnetic resonance imaging (MRI) were included in this study. Two reviewers independently evaluated unenhanced and gadoxetic acid-enhanced MRI (T1WI image set), and a combined T2WI and T1WI image set for differentiation between PDAC and other periampullary carcinomas using a rating scale, and the presence of the dark choledochal ring sign on T2WI, for all 60 tumours.

RESULTS

In PDAC, the dark choledochal ring sign on T2WI was considered positive in 23 cases by observer 1 and 24 cases by observer 2, but only in one or two CBD cancers, as determined by each observer, respectively. This resulted in sensitivities of 76.7% and 80% and specificities of 96.7% and 93.3% for observer 1 and 2, respectively, in the diagnosis of PDAC. Adding T2WI correctly led to a change of diagnosis in three and four cases of PDAC by each observer, respectively. Thus, there were significant differences between the two image sets for both observers in distinguishing between PDAC and other periampullary carcinomas (p = 0.02).

CONCLUSION

The presence of the dark choledochal ring sign on axial T2WI could be a complementary imaging feature indicative of PDAC to differentiate PDAC from other periampullary carcinomas at MRI.

Effects of heteroatom substitution in conjugated heterocyclic compounds on photovoltaic performance: from sulfur to tellurium

Band gaps of benzochalcogenophene-based organic semiconductors and the efficiencies of the corresponding photovoltaic devices can be tuned through heteroatom variation.

Gadoxetic acid-enhanced MRI for T-staging of gallbladder carcinoma: emphasis on liver invasion

OBJECTIVE

To evaluate the diagnostic performance of gadoxetic acid-enhanced MRI with an emphasis on the usefulness of the hepatobiliary phase (HBP) in T-staging of gallbladder carcinoma.

METHODS

66 patients with surgically confirmed gallbladder carcinoma underwent MRI. Two radiologists independently reviewed two sets of gadoxetic acid-enhanced MRI without and with the HBP. Local tumour spread was evaluated according to T-staging, and the results were compared with pathological findings. The diagnostic performance of two image sets to differentiate each T-stage was compared.

RESULTS

The sensitivities of MRI with the HBP to differentiate T1 vs ≥ T2 lesions, ≤ T2 vs ≥ T3 lesions and ≤ T3 vs T4 lesions were 96.3%, 85.7% and 100% for Observer 1 and 92.6%, 95.2% and 100% for Observer 2, respectively (p<0.0001). By adding the HBP, the sensitivities to differentiate ≤ T2 vs ≥ T3 lesions were increased from 66.7% to 85.7% for Observer 1 and from 81.0% to 95.2% for Observer 2, although there was no significant difference (p>0.05). The overall accuracies for T-staging were increased from 80.3% to 86.4% for Observer 1, a statistically significant degree (p=0.046), and from 83.8% to 87.9% for Observer 2 (p>0.05). The k-value for the two observers indicated excellent agreement.

CONCLUSION

Gadoxetic acid-enhanced MRI provided acceptable diagnostic performance for T-staging of gallbladder carcinoma. Addition of the HBP aids in the detection of liver invasion.

ADVANCES IN KNOWLEDGE

In the T-staging of gallbladder carcinoma, gadoxetic acid-enhanced MRI with the HBP may enhance detection of liver invasion.