Selective exciton formation in thin GaAs-AlGaAs quantum wells

We have found experimentally, that the exciton luminescence rise times in GaAs/AlGaAs quantum wells oscillate as a function of incident laser energies. Guided by Monte-Carlo simulations we interpret these results as the occurrence of selective LO-phonon assisted exciton formation

Endovascular Treatment of Ruptured Abdominal Aortic Aneurysms with Hostile Aortic Neck Anatomy

ObjectiveTo compare the mid-term results of endovascular aortic aneurysm repair (EVAR) for ruptured abdominal aortic aneurysms (RAAAs) in patients with favourable aortic neck anatomy (FNA) and hostile aortic neck anatomy (HNA).MethodsPatients treated for a RAAA in a high volume endovascular centre in the Netherlands between February 2009 and January 2014 were identified retrospectively and divided into two groups based on aortic neck anatomy, FNA and HNA. HNA was defined as RAAA with a proximal neck of <10 mm, or a proximal neck of 10–15 mm with a suprarenal angulation (α) >45° and/or an infrarenal angulation (β) >60°, or a proximal neck of >15 mm combined with α >60° and/or β >75°. Patient demographics, procedure details, 30 day and 1 year outcomes were recorded.ResultsOf 39 included patients, 17 (44%) had HNA. Technical success was 100% for FNA and 88% for HNA (p = .184). There were no type IA endoleaks on completion angiography in either group; however, more adjunctive procedures were necessary for intra-operative type IA endoleaks in the HNA group (24% vs. 0%, p = .029). Thirty day mortality rates were comparable, FNA 14% vs. HNA 12% (p = 1.000). There were no statistically significant differences at 1 year follow up in type I endoleaks, secondary endovascular procedures, or all cause mortality.ConclusionEmergency EVAR provides excellent results for treatment of RAAA patients with both FNA and HNA. EVAR in RAAAs with HNA is technically feasible and safe in experienced endovascular centres.Article history

Beneficial Effects of Pre-operative Exercise Therapy in Patients with an Abdominal Aortic Aneurysm: A Systematic Review

OBJECTIVE/BACKGROUND: The impact of post-operative complications in abdominal aortic aneurysm (AAA) surgery is substantial, and increases with age and concomitant co-morbidities. This systematic review focuses on the possible effects of pre-operative exercise therapy (PET) in patients with AAA on post-operative complications, aerobic capacity, physical fitness, and recovery. METHODS: A systematic search on PET prior to AAA surgery was conducted. The methodological quality of the included studies was rated using the Physiotherapy Evidence Database scale. The agreement between the reviewers was assessed with Cohen's kappa. RESULTS: Five studies were included, with a methodological quality ranging from moderate to good. Cohen's kappa was 0.79. Three studies focused on patients with an AAA (without indication for surgical repair) with physical fitness as the outcome measure. One study focused on PET in patients awaiting AAA surgery and one study focused on the effects of PET on post-operative complications, length of stay, and recovery. CONCLUSION: PET has beneficial effects on various physical fitness variables of patients with an AAA. Whether this leads to less complications or faster recovery remains unclear. In view of the large impact of post-operative complications, it is valuable to explore the possible benefits of a PET program in AAA surgery

Editor's Choice - Use of Disposable Radiation-absorbing Surgical Drapes Results in Significant Dose Reduction During EVAR Procedures

ObjectivesBecause of the increasing number of interventional endovascular procedures with fluoroscopy and the corresponding high annual dose for interventionalists, additional dose-protecting measures are desirable. The purpose of this study was to evaluate the effect of disposable radiation-absorbing surgical drapes in reducing scatter radiation exposure for interventionalists and supporting staff during an endovascular aneurysm repair (EVAR) procedure.MaterialsThis was a randomized control trial in which 36 EVAR procedures were randomized between execution with and without disposable radiation-absorbing surgical drapes (Radpad: Worldwide Innovations & Technologies, Inc., Kansas City, US, type 5511A). Dosimetric measurements were performed on the interventionalist (hand and chest) and theatre nurse (chest) with and without the use of the drapes to obtain the dose reduction and effect on the annual dose caused by the drapes.ResultsUse of disposable radiation-absorbing surgical drapes resulted in dose reductions of 49%, 55%, and 48%, respectively, measured on the hand and chest of the interventionalist and the chest of the theatre nurse.ConclusionsThe use of disposable radiation-absorbing surgical drapes significantly reduces scatter radiation exposure for both the interventionalist and the supporting staff during EVAR procedures

Effects of Anesthesia Type on Perioperative Outcome After Endovascular Aneurysm Repair

Purpose: To examine outcomes of endovascular aortic aneurysm repair (EVAR) using general, regional, or local anesthesia. Methods: From March 2009 to April 2011, patients were enrolled from 79 sites in 30 countries worldwide and treated with an Endurant Stent Graft System. Data were compared among 3 groups based on the method of anesthesia: general anesthesia (GA) was used in 785 (62%) patients, regional anesthesia (RA) in 331 (27%) patients, and local anesthesia (LA) in 145 (11%) patients. Multivariate logistic regression analysis was performed to adjust for possible confounding factors; outcomes are presented as the odds ratio and 95% confidence interval. Results: There were intercontinental differences in the distribution of type of anesthesia used for EVAR. Higher ASA (American Society of Anesthesiologists) classification was associated with predominant use of GA. Procedure time was reduced in LA (80.4 +/- 40.0 minutes) compared with RA (94.2 +/- 41.6 min, adjusted p=0.001) and GA (105.3 +/- 46.0 minutes, adjusted