Identifying Patients at High Risk for Post-EVAR Aneurysm Sac Growth.

PURPOSE: Post-EVAR (endovascular aneurysm repair) aneurysm sac growth can be seen as therapy failure as it is a risk factor for post-EVAR aneurysm rupture. This study sought to identify preoperative patient predictors for developing post-EVAR aneurysm sac growth. MATERIAL AND METHODS: A systematic review was conducted to select potential predictive preoperative factors for post-EVAR sac growth (including a total of 34.886 patients), which were evaluated by a retrospective single-center analysis of patients undergoing EVAR between 2009 and 2019 (N=247) with pre-EVAR computed tomography scans and at least 1 year follow-up. The primary study outcome was post-EVAR abdominal aortic aneurysm (AAA) sac enlargement (≥5 mm diameter increase). Multivariate Cox regression and Kaplan-Meier survival curves were constructed. RESULTS: Potential correlative factors for post-EVAR sac growth included in the cohort analysis were age, sex, anticoagulants, antiplatelets, renal insufficiency, anemia, low thrombocyte count, pulmonary comorbidities, aneurysm diameter, neck diameter, neck angle, neck length, configuration of intraluminal thrombus, common iliac artery diameter, the number of patent lumbar arteries, and a patent inferior mesenteric artery. Multivariate analysis showed that infrarenal neck angulation (hazard ratio, 1.014; confidence interval (CI), 1.001-1.026; p=0.034) and the number of patent lumbar arteries (hazard ratio, 1.340; CI, 1.131-1.588; p<0.001) were associated with post-EVAR growth. Difference in estimated freedom from post-EVAR sac growth for patients with ≥4 patent lumbar arteries versus <4 patent lumbar arteries became clear after 2 years: 88.5% versus 100%, respectively (p<0.001). Of note, 31% of the patients (n=51) with ≥4 patent lumbar arteries (n=167) developed post-EVAR sac growth. In our cohort, the median maximum AAA diameter was 57 mm (interquartile range [IQR] = 54-62) and the median postoperative follow-up time was 54 months (IQR = 34-79). In all, 23% (n=57) of the patients suffered from post-EVAR growth. The median time for post-EVAR growth was 37 months (IQR = 24-63). In 46 of the 57 post-EVAR growth cases (81%), an endoleak was observed; 2.4% (n=6) of the patients suffered from post-EVAR rupture. The total mortality in the cohort was 24% (n=60); 4% (n=10) was AAA related. CONCLUSIONS: This study showed that having 4 or more patent lumbar arteries is an important predictive factor for postoperative sac growth in patients undergoing EVAR. CLINICAL IMPACT: This study strongly suggests that having 4 or more patent lumbar arteries should be included in preoperative counseling for EVAR, in conjunction to the instructions for use (IFU).

Nationwide study of the treatment of mycotic abdominal aortic aneurysms comparing open and endovascular repair in The Netherlands.

OBJECTIVE: Mycotic aneurysms of the abdominal aorta (MAAA) can be treated by open repair (OR) or endovascular aneurysm repair (EVAR). This nationwide study provides an overview of the situation of MAAA treatment in The Netherlands in 2016. METHODS: A retrospective cohort study was conducted with all centers that registered aortic abdominal aneurysms in the Dutch Surgical Aneurysm Audit in 2016. Questionnaires on 1-year outcomes were sent to all centers that treated patients with MAAA. The primary aim was to determine 30-day and 1-year mortality and morbidity of OR- and EVAR-treated patients. Morbidity was determined by the need for reoperations and the number of readmissions to the hospital. RESULTS: Twenty-six MAAA were detected in the Dutch Surgical Aneurysm Audit database of 2016, resulting in an incidence of 0.7% of all registered abdominal aortic aneurysms. The 30-day mortality for OR and EVAR treated patients was 1 in 13 and 0 in 13, respectively. Major and minor reinterventions within 30 days were needed for two (one OR and one EVAR) and two (one OR and one EVAR) patients, respectively. Two patients (15.4%) in the OR group and one patient (7.7%) in the EVAR group were readmitted to hospital within 30 days. In total, 1-year outcomes of 23 patients were available. In the OR group, one patient (9.1%) died in the first postoperative year. There was one major reintervention (removal of endoprosthesis and spiralvein reconstruction) in the EVAR group. Two patients (18.2%) treated with OR and two (16.7%) treated with EVAR required a minor reintervention. In both groups, four patients (OR, 36.4%; EVAR, 33.3%) were readmitted to hospital within 1 year postoperatively. CONCLUSIONS: Both OR- and EVAR-treated patients show acceptable clinical outcomes after 30 days and at the 1-year follow-up. Depending on the clinical course of the patient, EVAR may be considered in the management of this disease.

Clinical outcomes of postcarotid endarterectomy hypertension.

OBJECTIVE: The objective of this study was to determine the clinical relevance of postcarotid endarterectomy hypertension (PEH) by investigating the effect of PEH on hospital length of stay (LOS) and by investigating short-term and long-term complications of PEH. In addition, risk factors for PEH were determined. METHODS: A single-center retrospective cohort study was performed. Demographic, preoperative, intraoperative, and postoperative outcomes of 192 patients undergoing carotid endarterectomy were evaluated. Outcomes were compared between patients with PEH and patients without PEH. PEH was defined as an acute systolic blood pressure (SBP) rise >170 mm Hg or persistent SBP >150 mm Hg on the ward and leading to the consultation of an internist. The overall survival and event-free survival were compared using a Kaplan-Meier analysis and a Cox regression analysis. A multivariate logistic regression analysis was performed to determine risk factors for PEH. RESULTS: PEH developed in 44 of 192 patients (25%). Preoperative hypertension (SBP >150 mm Hg) was determined to be a risk factor for PEH (odds ratio, 3.3; 95% confidence interval [CI], 1.6-6.9). Hospital LOS was prolonged in patients with PEH compared with patients without PEH (median LOS of 5 days vs 3 days, respectively; P < .001). No difference in the occurrence of ischemic neurologic events or rebleeding during hospitalization was observed (P = .58 and P = .72, respectively). Cardiovascular and ischemic neurologic events during follow-up did not occur more often in patients with PEH than in patients without PEH (P = .46). There was no difference in mortality between the PEH and non-PEH groups (hazard ratio, 1.6; 95% CI, 0.6-4.3). The same applies to the event-free survival (hazard ratio, 0.77; 95% CI, 0.4-1.7). Combined event-free survival for stroke and myocardial infarction was 92% (95% CI, 87%-97%) at 2 years for patients without PEH and 86% (95% CI, 74%-98%) at 2 years for patients with PEH (P = .25). Event-free survival for mortality was 90% (95% CI, 85%-96%) at 2 years for patients without PEH and 94% (95% CI, 86%-100%) at 2 years for patients with PEH (P = .36). CONCLUSIONS: Patients with PEH had a significant increase in hospital LOS. However, adverse short-term and long-term events did not occur more often in patients with PEH. High preoperative SBP was identified as a risk factor for PEH; no other demographic and clinical variables were associated with PEH.

Chimney Technique to Preserve Visceral Flow in a Coral Reef Aorta.

The coral reef aorta (CRA) is a rare phenomenon of extreme calcification in the juxtarenal and suprarenal aorta. Open revascularization has an overall in-hospital mortality rate of 13%. We present a patient with a suprarenal CRA with colon ischemia. She has an extensive past medical history of percutaneous transluminal angioplasty and stenting of the celiac trunk (CT) and superior mesenteric artery (SMA). The computed tomography angiography showed a CRA of the suprarenal aorta with occlusion of the CT stent and near occlusion of the SMA stent. Our case illustrates that the CRA in the suprarenal part of the aorta can be treated well by chimney graft procedure, although owing to lack of long-term follow-up, it might be reserved for high-risk candidates for (thoraco)abdominal aortic surgery.

Endovascular Revascularization of a Chronic Occluded Aortobifemoral Bypass.

Bilateral limb occlusion after aortobifemoral (ABF) prosthesis occurs in 1-3% patients. Multiple remedial choices are known in literature to manage a bilateral occluded ABF such as "redo" ABF bypass, axillobifemoral bypass, endovascular recanalization of the native aortoiliac system, and thrombectomy. We present a patient with an occluded ABF bypass since 2001. A new minimal invasive treatment strategy was performed by traversing the occluded limbs with aortic re-entry using stiff Terumo wires. To make way for safe passing of the stents, kissing balloon angioplasty was performed of the entire ABF bypass. Kissing Viabahn (W. L. Gore & Associates, Flagstaff, AZ) balloon-expandable stents were placed in the proximal part of the ABF bypass and extended with a Viabahn self-expandable stent (standard Viabahn). This option should be added to the known multiple remedial choices in case of bilateral limb occlusion of an ABF.

Machine learning to help researchers evaluate biases in clinical trials: a prospective, randomized user study.

OBJECTIVE: Assessing risks of bias in randomized controlled trials (RCTs) is an important but laborious task when conducting systematic reviews. RobotReviewer (RR), an open-source machine learning (ML) system, semi-automates bias assessments. We conducted a user study of RobotReviewer, evaluating time saved and usability of the tool. MATERIALS AND METHODS: Systematic reviewers applied the Cochrane Risk of Bias tool to four randomly selected RCT articles. Reviewers judged: whether an RCT was at low, or high/unclear risk of bias for each bias domain in the Cochrane tool (Version 1); and highlighted article text justifying their decision. For a random two of the four articles, the process was semi-automated: users were provided with ML-suggested bias judgments and text highlights. Participants could amend the suggestions if necessary. We measured time taken for the task, ML suggestions, usability via the System Usability Scale (SUS) and collected qualitative feedback. RESULTS: For 41 volunteers, semi-automation was quicker than manual assessment (mean 755 vs. 824 s; relative time 0.75, 95% CI 0.62-0.92). Reviewers accepted 301/328 (91%) of the ML Risk of Bias (RoB) judgments, and 202/328 (62%) of text highlights without change. Overall, ML suggested text highlights had a recall of 0.90 (SD 0.14) and precision of 0.87 (SD 0.21) with respect to the users' final versions. Reviewers assigned the system a mean 77.7 SUS score, corresponding to a rating between "good" and "excellent". CONCLUSIONS: Semi-automation (where humans validate machine learning suggestions) can improve the efficiency of evidence synthesis. Our system was rated highly usable, and expedited bias assessment of RCTs.

Cost-effectiveness of intraoperative nerve monitoring in avoidance of bilateral recurrent laryngeal nerve injury in patients undergoing total thyroidectomy.

BACKGROUND: Intraoperative nerve monitoring (IONM) provides dynamic neural information and is recommended for high-risk thyroid surgery. In this analysis, the cost-effectiveness of IONM in preventing bilateral recurrent laryngeal nerve (RLN) injury was investigated. METHODS: A Markov chain model was constructed based on IONM use. The base-case patient was defined as a 40-year-old woman presenting with a 4·1-cm left-sided papillary thyroid cancer who developed RLN injury with loss of monitoring signal during planned bilateral thyroidectomy. It was hypothesized that, if the surgeon had used IONM, the RLN injury would have been detected and the operation would have been concluded as a thyroid lobectomy to avoid the risk of contralateral RLN injury. Cost in US dollars was converted to euros; probabilities and utility scores were identified from the literature and government resources. Length of follow-up was set as 20 years, and willingness-to-pay (WTP) as €38 000 (US $50 000) per quality-adjusted life-year (QALY). RESULTS: At the end of year 20, the not using IONM strategy accrued €163 995·40 (US $215 783·43) and an effectiveness of 14·15 QALYs, whereas use of the IONM strategy accrued €170 283·68 (US $224 057·48) and an effectiveness of 14·33 QALYs. The incremental cost-effectiveness ratio, comparing use versus no use of IONM, was €35 285·26 (US $46 427·97) per QALY, which is below the proposed WTP, indicating that IONM is the preferred and cost-effective management plan. A Monte Carlo simulation test that considered variability of the main study factors in a hypothetical sample of 10 000 patients showed IONM to be the preferred strategy in 85·8 per cent of the population. CONCLUSION: Use of IONM is cost-effective in patients undergoing bilateral thyroid surgery.

Determinants of Acute Kidney Injury and Renal Function Decline After Endovascular Abdominal Aortic Aneurysm Repair.

OBJECTIVE/BACKGROUND: Endovascular aneurysm repair (EVAR) may be associated with renal injury and more insight is needed into potential risk factors. The aim was to identify clinical, anatomical, and peri-procedural parameters as potential risk factors for the occurrence of acute kidney injury (AKI) and to evaluate chronic kidney disease (CKD) after EVAR. METHODS: A cohort of 212 consecutive patients who underwent elective EVAR for abdominal aortic aneurysm from January 2009 to October 2016 was included. A subgroup of 149 patients with 2 years follow-up was compared with a set of 135 non-operated aneurysm patients with smaller aneurysms (similar cardiovascular risk profile) to assess CKD. Primary outcomes were AKI (Acute Kidney Injury Network criteria) and CKD measured by estimated glomerular filtration rate (Kidney Disease Improving Global Outcomes guidelines). For AKI, candidate risk factors were identified by univariate and multivariate logistic regression analysis; for chronic renal function decline, risk factors were identified using Cox regression analysis. RESULTS: AKI occurred in 30 patients (15%). On multivariate analysis, the use of angiotensin II blocker (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.38-12.07) and peri-operative complications (OR 3.12, 95% CI 1.20-8.10) were independent risk factors for AKI, whereas statin use was a protective factor (OR 0.19, 95% CI 0.07-0.52). EVAR resulted in a significant increase (23.5%) in the occurrence of CKD compared with the control group (6.7%; p <.001). On univariate and multivariate Cox regression the risk factors: aortic neck diameter (per mm increase) (hazard ratio [HR] 1.13, 95% CI 1.02-1.25), renal artery stenosis >50% (HR 2.24, 95% CI 1.05-4.79), and the occurrence of AKI (HR 2.19, 95% CI 0.99-4.85) were significant predictors of CKD. CONCLUSION: This study identified use of angiotensin II blockers and peri-operative complications as risk factors for AKI. In addition, the problem of renal function decline after EVAR is highlighted, which indicates that prolonged protective measures (e.g., in those patients at high risk) over time are needed to improve patient outcomes.

Endpoints for screening thyroid cancer in the Republic of Korea: thyroid specialists' perspectives.

Cancer screening is aimed primarily at reducing deaths from the specific cancer. Thyroid-specific cancer mortality may be the most ambitious endpoint for obtaining estimates of screening effect. Numerous observations have accumulated over the years, indicating that thyroid cancer mortality endpoint has been difficult to study and is confounded by population heterogeneity, provision of randomization, and requirement of large cohorts with sufficiently long follow-up due to the excellent prognosis of the cancer. Accordingly, it may be important to reconsider how to best measure thyroid cancer screening efficacy. Recommendations against thyroid cancer screening should be based upon trials designed to evaluate its effectiveness not only in significant reduction in cancer mortality, but also of other distinct endpoints. It is desirable to evaluate derivative endpoints that can reliably predict reductions in mortality. The term "derivative" means a variable that is related to the true endpoint and is likely to be observable before the primary endpoint. Derivative endpoints may include thyroid cancer incidence, the proportion of early-stage tumors detected, more treatable stage, the identification of small tumors (to maintain in observation), decrease in the number of people who develop metastatic disease, the increased chance of lesser extent surgery, and the application of minimally invasive approaches, as well as no need for lifelong thyroid replacement therapy, a consistent follow-up, low-dose or no RAI administration and risk factor assessments where case findings should be continuous. The Korean guidelines for thyroid cancer national-level screening were published by a relevant group of multidisciplinary thyroid experts. It was concluded that the evidence is insufficient to balance the benefits and harms of thyroid cancer screening. However, the paper seems to raise the necessary investments in future research and demand a complete analysis for derivative endpoints, and offer screening participants with complete information necessary to make decisions that will provide them with the most value when a small thyroid cancer is screen-identified.

Multilevel Mycotic Aneurysms Due to Salmonella Infection: Case Report and Review of the Literature.

Infected or mycotic aneurysms (MAs) of the aorta and adjacent arteries are rare and difficult to treat. We report a unique case of a Salmonella serotype enteritidis-induced rapidly expanding aortic and iliac pseudoaneurysm during preoperative workup. Based on the presented case, we postulate that the agressive nature of Salmonella enteritidis MAs should not be underestimated. If postponed intervention is chosen and the patient is managed conservatively with antibiotic therapy to create a window of definitive diagnosis, one should consider close follow-up imaging to observe progression of the pseudoaneurysm. This may prevent the need of acute intervention.

Focal Aortic Dissection With Significant Stenosis: A Rare Long Term Complication After TEVAR for Blunt Traumatic Aortic Injury in an Adolescent Patient.

Background: Thoracic endovascular aortic repair (TEVAR) in children and adolescents after blunt traumatic aortic injury (BTAI) is being performed increasingly despite no endovascular graft being approved for TEVAR in this population. The smaller diameter of the aorta and access vessels and steeper angle of the aortic arch pose specific challenges for TEVAR in this population. Moreover, data are lacking regarding medium to long term complications. This case presents an adolescent patient who underwent TEVAR for BTAI and suffered a focal aortic dissection several months later. Report: The patient initially presented after a motor vehicle accident and underwent an uncomplicated TEVAR procedure with a 28 mm diameter stent graft (the smallest device available at the time) for Grade III traumatic aortic dissection; the native aortic diameter was 15 mm. The diameter mismatch was accepted due to the lifesaving nature of the procedure. More than 7 months later the patient presented to the emergency department after not being able to urinate for several days and experiencing pain, tingling, and weakness in both legs. Blood samples showed a severe acute kidney injury and computed tomography angiography showed significant aortic stenosis in the distal part of the stent graft, probably caused by a focal dissection. The stenosis and dissection were successfully treated using a Palmaz stent, after which his renal function and extremity complaints recovered. Conclusion: The focal dissection was probably caused by stress on the aortic wall due to the aorta-stent graft diameter mismatch. This case demonstrates that complications after TEVAR in adolescents can arise months after the initial procedure and underscores the need for continued vigilance, especially in cases with an aorta-stent graft mismatch. The threshold for additional imaging and consultation by a vascular surgeon should be low.

Recurrent laryngeal nerve injury in video-assisted thyroidectomy: lessons learned from neuromonitoring.

INTRODUCTION: The objective of the study was to assess the mechanism of recurrent laryngeal nerve (RLN) injury during video-assisted thyroidectomy (VAT). METHODS: The study examined 201 nerves at risk (NAR). VAT with laryngeal neuromonitoring (LNM) was outlined according to this scheme: (a) preparation of the operative space; (b) vagal nerve stimulation (V1); (c) ligature of the superior thyroid vessels; (d) visualization, stimulation (R1), and dissection of the RLN; (e) extraction of the lobe; (f) resection of the thyroid lobe; (g) final hemostasis; (h) verification of the electrical integrity of the RLN (V2, R2). The site, cause, and circumstance of nerve injury were elucidated with the application of LNM. Laryngeal nerve injuries were classified into type 1 injury (segmental) and 2 (diffuse). RESULTS: Fourteen nerves (6.9 %) experienced loss of R2 and V2 signals. 80 percent of lesions occurred in the distal 1 cm of the course of the RLN. The incidence of type 1 and 2 injuries was 71 and 29 % respectively. The mechanisms of injury were traction (70 %) and thermal (30 %). Traction lesions were created during the extraction of the lobe from the mini-incision [point (e)]. Thermal injury occurred during energy-based device use in (f) and (g) circumstances. CONCLUSIONS: RLN palsy still occurs with routine endoscopic identification of the nerve, even combined with LNM. LNM has the advantage of elucidating the mechanism of RLN injury. Traction and thermal RLN injuries are the most frequent lesions in VAT.

Wall Shear Stress Assessment of the False Lumen in Acute Type B Aortic Dissection Visualized by 4-Dimensional Flow Magnetic Resonance Imaging: An Ex-Vivo Study.

BACKGROUND: Four-dimensional flow magnetic resonance imaging (4D flow MRI) can accurately visualize and quantify flow and provide hemodynamic information such as wall shear stress (WSS). This imaging technique can be used to obtain more insight in the hemodynamic changes during cardiac cycle in the true and false lumen of uncomplicated acute Type B Aortic Dissection (TBAD). Gaining more insight of these forces in the false lumen in uncomplicated TBAD during optimal medical treatment, might result in prediction of adverse outcomes. METHODS: A porcine aorta dissection model with an artificial dissection was positioned in a validated ex-vivo circulatory system with physiological pulsatile flow. 4D flow MR images with 3 set heartrates (HR; 60 bpm, 80 bpm and 100 bpm) were acquired. False lumen volume per cycle (FLV), mean and peak systolic WSS were determined from 4D flow MRI data. For validation, the experiment was repeated with a second porcine aorta dissection model. RESULTS: During both experiments an increase in FLV (initial experiment: ΔFLV = 2.05 ml, p < 0.001, repeated experiment: ΔFLV = 1.08 ml, p = 0.005) and peak WSS (initial experiment: ΔWSS = 1.2 Pa, p = 0.004, repeated experiment: ΔWSS = 1.79 Pa, p = 0.016) was observed when HR increased from 60 to 80 bpm. Raising the HR from 80 to 100 bpm, no significant increase in FLV (p = 0.073, p = 0.139) was seen during both experiments. The false lumen mean WSS increased significant during initial (2.71 to 3.85 Pa; p = 0.013) and non-significant during repeated experiment (3.22 to 4.00 Pa; p = 0.320). CONCLUSION: 4D flow MRI provides insight into hemodynamic dimensions including WSS. Our ex-vivo experiments showed that an increase in HR from 60 to 80 bpm resulted in a significant increase of FLV and WSS of the false lumen. We suggest that strict heart rate control is of major importance to reduce the mean and peak WSS in uncomplicated acute TBAD. Because of the limitations of an ex-vivo study, 4D flow MRI will have to be performed in clinical setting to determine whether this imaging model would be of value to predict the course of uncomplicated TBAD.

Mononuclear phagocytes egress from an in vitro model of the vascular wall by migrating across endothelium in the basal to apical direction: role of intercellular adhesion molecule 1 and the CD11/CD18 integrins.

Little is known about how mononuclear phagocytes (MP) are cleared from sites of inflammation as inflammatory lesions resolve. In this study, the possibility that MP could be cleared from tissues by migrating across endothelium in the basal to apical direction was investigated. In an in vitro model of a blood vessel wall consisting of human umbilical vein endothelial cells (HUVEC) grown on amniotic tissue, a majority of MP that initially transmigrated into the amnion later exited by migrating back across the endothelium in the basal to apical direction. MP that egressed from these cultures adhered to the apical surface of the endothelium or were found nonadherent in the medium above the endothelium. Egression of MP continued throughout the 4-d period examined, displaying higher than first order kinetics and a t(1/2) of approximately 24 h. These kinetics were decreased by increasing the volume of medium bathing the cultures, suggesting that a soluble factor(s) regulates the rate of egression. In contrast, the kinetics were accelerated by pretreating the endothelium with IL-1. The initial phase of this increased rate of egression was inhibited by antibodies to inter- cellular adhesion molecule 1 (ICAM-1) or CD18 by 100 and 71%, respectively. Immunostaining revealed that ICAM-1 was present on the apical and basal surfaces of umbilical vein endothelium in vitro and in situ. These data demonstrate that MP can traverse endothelium in the basal to apical direction, and lend insight into the mechanisms by which this process occurs.

A reduction in cardiac arrests and duration of clinical instability after implementation of a paediatric rapid response system.

OBJECTIVE: To determine the effects of a multifaceted paediatric rapid response system on the duration of predefined clinical instability and the subsequent rate of cardiac arrests. METHODS: An interrupted time series study coupled with a retrospective chart review to evaluate the effects of implementing a four component paediatric rapid response system. All patients in a 136-bed university-affiliated paediatric hospital from August 2003 to May 2007 were considered. The main outcome measures included rate of cardiac arrests as indicated by the number of patient days between ward paediatric cardiac arrests and duration of predefined clinical instability before evaluation by critical care personnel. RESULTS: The mean time interval between cardiac arrests increased significantly with the establishment of the rapid response system from a baseline of 2512 to 9418 patient days. The median duration of clinical instability decreased from 9 h 55 min to 4 h 15 min post intervention (p=0.028). CONCLUSIONS: The implementation of a paediatric rapid response system is associated with a significant reduction in the rate of cardiac arrests and duration of clinical instability before evaluation by critical care personnel. This study provides evidence that implementation of a rapid response system brings emergency personnel to deteriorating patients earlier, thus preventing cardiac arrests.

The Influence of Aortic Wall Elasticity on the False Lumen in Aortic Dissection: An In Vitro Study.

BACKGROUND: Hemodynamics, dissection morphology, and aortic wall elasticity have a major influence on the pressure in the false lumen. In contrast to aortic wall elasticity, the influence of hemodynamics and dissection morphology have been investigated often in multiple in vitro and ex vivo studies. The purpose of this study was to evaluate the influence of aortic wall elasticity on the diameter and pressure of the false lumen in aortic dissection. METHODS: An artificial dissection was created in 3 ex vivo porcine aortas. The aorta models were consecutively positioned in a validated in vitro circulatory system with physiological pulsatile flow. Each model was imaged with ultrasound on 4 positions along the aorta and the dissection. At these 4 locations, pressure measurement was also performed in the true and false lumen with an arterial catheter. After baseline experiments, the aortic wall elasticity was adjusted with silicon and the experiments were repeated. RESULTS: The aortic wall elasticity was decreased in all 3 models after siliconizing. In all 3 siliconized models, the diameters of the true and false lumen increased at proximal, mid, and distal location, while the mean arterial pressure did not significantly change. CONCLUSIONS: In this in vitro study, we showed that aortic wall elasticity is an important parameter altering the false lumen. An aortic wall with reduced elasticity results in an increased false lumen diameter in the mid and distal part of the false lumen. These results can only be transferred to corresponding clinical situations to a limited extent.

The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective.

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Combining rare alleles and grouped pollen donors to assign paternity in pollen dispersal studies.

PREMISE: Pollen dispersal plays a critical role in gene flow of seed plants. Most often, pollen dispersal is measured using paternity assignment. However, this approach can be time-consuming because it typically entails genotyping all pollen donors, receptors, and offspring at several molecular markers. METHODS: We developed a faster, simpler protocol to track paternity, using pollen receptors and grouped pollen donors that possess rare alleles. We tested this approach using wind-pollinated Amaranthus tuberculatus and insect-pollinated Solanum lycopersicum. After screening potential markers for rare alleles, we grew both species in experimental arrays under field conditions. RESULTS: All tested A. tuberculatus seeds and 97% of S. lycopersicum fruits could be assigned to the grouped pollen donors using each of two markers. From these results, we could infer paternity of untested offspring and assess pollen dispersal patterns in each array. DISCUSSION: By combining rare alleles and grouped pollen donors, we could assess pollen dispersal for both species and across all arrays after genotyping a small number of pollen donors and a representative subset of offspring. While directly applicable to A. tuberculatus and S. lycopersicum, this approach could be used in other species to assess pollen dispersal under field conditions.

Cost-Effectiveness of Drug-Eluting Stents for Infrapopliteal Lesions in Patients with Critical Limb Ischemia: The PADI Trial.

PURPOSE: Drug-eluting stents (DES) improve clinical and morphological long-term results compared to percutaneous transluminal angioplasty (PTA) with bailout bare metal stenting (BMS) in patients with critical limb ischemia (CLI) and infrapopliteal lesions (PADI trial). We performed a cost-effectiveness analysis of DES compared to PTA ± BMS in cooperation with Dutch health insurance company VGZ, using data from the PADI trial. MATERIALS AND METHODS: In the PADI trial, adults with CLI (Rutherford category ≥ 4) and infrapopliteal lesions were randomized to receive DES with paclitaxel or PTA ± BMS. Seventy-four limbs (73 patients) were treated with DES and 66 limbs (64 patients) with PTA ± BMS. The costs were calculated by using the mean costs per stent multiplied by the mean number of stents used per patient (€750 × 1.8 for DES vs €250 × 0.3 for PTA ± BMS). These costs were compared with the costs of major amputation (€16.000) and rehabilitation (first year €15.750, second year €7.375 and third year €3.600). RESULTS: The 5-year major amputation rate was lower in the DES group (19.3% vs 34.0% for PTA ± BMS; p = 0.091). In addition, the 5-year amputation-free survival and event-free survival were significantly higher in the DES group (31.8% vs 20.4%, p=0.043; and 26.2% vs 15.3%, p=0.041, respectively). After 1 year, the cost difference per patient between DES and PTA ± BMS is €1.679 in favor of DES and €2.694 after 3 years. CONCLUSION: In our analysis, DES are cost-effective due to the higher hospital costs of amputation and rehabilitation in the PTA ± BMS group. LEVEL OF EVIDENCE: Level 1b, analysis based on clinically sensible costs and randomized controlled trial.