Forecasting aortic aneurysm rupture: A systematic review of seasonal and atmospheric associations.

BACKGROUND: Abdominal aortic aneurysms (AAAs) represent a significant burden of disease worldwide, and their rupture, without treatment, has an invariably high mortality rate. Whereas some risk factors for ruptured AAAs (rAAAs) are well established, such as hypertension, smoking, and female sex, the impact of seasonal and meteorologic variables is less clear. We systematically reviewed the literature to determine whether these variables are associated with rAAA. METHODS: Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled proportions and incidence rate ratios (IRRs) for the different months and seasons. Funnel plots were constructed to assess for publication bias. Given the poor methodologic quality of included studies, a sensitivity analysis was performed on better-quality studies, which scored 6 and above of 9 in the author-modified Newcastle-Ottawa Scale. RESULTS: The pooled proportion of rAAA was highest in the autumn season (incidence rate, 26.6%; 95% confidence interval [CI], 25.6%-27.7%; I2 = 15.4%), followed by winter (incidence rate, 26.2%; 95% CI, 24.1%-28.2%; I2 = 72.4%), and lowest in summer (incidence rate, 21.1%; 95% CI, 19.3%-23.0%; I2 = 70.4%). The IRRs of rAAA were -6.9% (95% CI, -9.8% to -3.9%), -19.5% (95% CI, -22% to -16.8%), +10.5% (95% CI, 7.2%-13.9%), and +18.1% (95% CI, 15%-22%) in spring, summer, autumn, and winter compared with the remaining seasons, respectively (all P < .0001), thus affirming existence of seasonal variation. The pooled proportion of rAAA was highest in December (incidence rate, 8.9%; 95% CI, 7.1%-10.9%; I2 = 54.5%) but lowest in July (incidence rate, 5.7%; 95% CI, 4.2%-7.3%; I2 = 54.5%). The IRR was significantly the highest in January (IRR, 1.14; 95% CI, 1.01-1.29; P = .031) but lowest in July (IRR, 0.75; 95% CI, 0.65-0.87; P < .0001). There is also some evidence for a possible association with atmospheric pressure. Associations with temperature and daylight hours, however, are at best speculative. CONCLUSIONS: Autumn and winter are significantly associated with a higher incidence of rAAAs, and autumn is associated with the highest rupture incidence of all the seasons. However, the inability to appropriately control for other confounding factors known to increase the risk of AAA rupture precludes any additional recommendations to alter current provision of vascular services on the basis of these data.

Neoaortic Xenoprosthetic Grafts for Treatment of Mycotic Aneurysms and Infected Aortic Grafts.

BACKGROUND: There is no international consensus regarding the optimum management of infected aortae (mycotic aneurysms, infected aortic grafts). Neoaortoiliac reconstruction has advantages over extra-anatomical bypass grafting; however, the use of autologous vein is associated with venous hypertension and compartment syndrome, alternatively cadaveric homografts are associated with high rates of perianastomotic hemorrhage, limb occlusion, and pseudoaneurysm. Arterial repair using xenoprosthetic patches is associated with lower infection rates compared to the use of prosthetic material. The aim of this case series and literature review is to report the use of xenoprosthetic bovine biomaterial for neoaortic repair of mycotic aneurysmal disease and infected aortic grafts. METHODS: Patients with evidence of infected aortic grafts or mycotic aneurysms who were suitable for open aortic surgery were included. Following removal of the graft/excision of the aneurysmal sac, a 10 × 16 cm XenoSure Biologic Surgical Patch (LeMaitre, Germany) was rolled into a tube, or bifurcated tube graft, and secured with prolene sutures. Proximal and distal anastomoses were conducted as per standard aortic anastomoses. Patients were continued on long-term antibiotics and surveyed with computerized tomography at 1, 3, 6, and 12 months. RESULTS: Six patients underwent bovine aortic repair between 2013 and 2015: an infected Dacron aortobi-iliac graft causing iliac pseudoaneurysm, an infected Dacron aortic graft from open repair later relined with endovascular stent graft, a mycotic iliac aneurysm, and 3 mycotic aortic aneurysms. All were treated with bovine reconstructed aortic grafts or patches. Patients had a median age of 69.5 years (range 67-75), with perioperative and 30-day mortality of 0%. Median follow-up was 13 months (range 2-23). Postoperative contrast-enhanced computed tomography revealed no evidence of infection at the operative site in all patients. Freedom from reinfection and reintervention was 100%. CONCLUSIONS: Xenoprosthetic (bovine) neoaortic grafts are an alternative method to treat infected aortae with excellent short-term freedom from infection and reintervention. Optimum duration of postoperative antibiotic therapy remains undetermined. Further cases and longer follow-up are required to determine the true efficacy of this technique.

Tuberocephalus tsengi (Tao, 1963) STAT. REV. (Hemiptera: Aphididae), an East Asian Artemisia-feeding aphid species introduced to Britain.

Tuberocephalus tsengi (Tao, 1963) STAT. REV., an aphid species described from China, is reported feeding on Artemisia vulgaris in southern England. This species is here redescribed and distinguished from T. sasakii (Matsumura, 1917), with which it has previously been synonymised.

Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study.

OBJECTIVES: Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus. METHODS: A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). 'Good' and 'very good' consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively. RESULTS: Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, 'good' and 'very good' consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, 'very good' consensus was achieved for 3/3 statements. CONCLUSIONS: The main findings from this study were that there was 'good' or 'very good' consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.

Spontaneous Accessory Renal Artery Aneurysm Rupture in a Patient With Neurofibromatosis Type 1: A Case Report.

True renal artery aneurysms are rare. Ruptured aneurysms are even rarer but can have devastating consequences. Renal artery aneurysms most commonly occur in patients with hypertension, atherosclerosis, or fibromuscular dysplasia. Treatment options can range from embolization to nephrectomy. We describe an interesting case of spontaneous accessory renal artery aneurysm rupture in a 44-year-old female with neurofibromatosis type 1 (NF1) who otherwise had no medical problems. She was successfully treated with selective coil embolization, recovered without complications, and maintained preoperative renal function.

Adjacent thoracic lymph node metastases originating from two separate primary cancers: case report.

Reported is an unusual case of adjacent thoracic lymph nodes demonstrating metastases from two different primary malignancies. A 51 year-old woman with a previous history of bilateral breast cancer underwent a radical gastro-oesophagectomy for adenocarcinoma of the lower third of the oesophagus. The resection specimen demonstrated breast and oesophageal metastases in adjacent thoracic lymph nodes. Mechanisms for this phenomenon, including the known local immune suppression on lymphoid cells by oesophageal carcinoma cells, are discussed.

Changes in temperature affect the risk of abdominal aortic aneurysm rupture.

BACKGROUND: There is a well-established link between exposure to hot and cold temperatures and an increased risk of cardiovascular hospitalization or death. There is also contrasting evidence of a seasonal increase in aortic ruptures related to atmospheric pressure, but an association with environmental temperature has never been formally modelled. METHODS: Using a prospective database, we identified 295 patients who were operated in a single centre for ruptured abdominal aortic aneurysm in south-east Queensland between 1990 and 2010. We matched patients to their nearest weather station to estimate their exposure to temperature and air pressure in the days leading up to their rupture. We used the case-crossover method to estimate the risks of temperature, which we allowed to be non-linear (increased risks at high and low temperatures) and delayed by up to 25 days. RESULTS: There was an immediate increase in risk after exposure to cold, and a delayed risk after exposure to heat. An increased risk after exposure to high pressures disappeared after adjusting for temperature. At a mean temperature of 19°C (66°F), the odds ratio for rupture was 1.73 (95% confidence interval: 1.09, 2.76) compared with the reference temperature of 24°C. CONCLUSION: This is the first study to demonstrate an association between temperature and risk of aortic aneurysm rupture in the Southern Hemisphere. The physiological changes caused by thermoregulation may be a trigger for those people with a fragile aneurysm.

Aortocaval fistula: current management strategies.

BACKGROUND: There has been a trend towards favouring endovascular repair for much acute aortic pathology. We undertook a review of the literature to determine if an endovascular approach could complement the traditional treatment of aortocaval fistula (ACF), a rare complication of abdominal aortic aneurysm. METHODS: A literature search was undertaken on PubMed using appropriate search terms. Case series and reviews reporting presentation, diagnosis and operative management (open and endovascular techniques) of ACF were selected and discussed. RESULTS: Open surgical treatment of ACF has an associated morbidity and mortality - mainly from excessive blood loss. Open repair mortality rates are reported around 30%, but some centres report far lower rates based on preoperative diagnosis of the ACF. These rates appear to be reduced when using endovascular repair in selected cases, with success rates of up to 96%. Reiteration of the importance of diagnosis of ACF preoperatively was the common denominator with both open and endovascular repair. CONCLUSIONS: Endovascular exclusion appears to be an efficacious means of treating ACF and averting the significant blood loss commonly encountered in conventional repair of these lesions. However, some reviews have suggested equal success with open repair. There is limited available published literature on ACF management and outcome, and likely reporting bias attached to both open and endovascular results that are published. With a randomized controlled trial unlikely to occur, a prospective registry may provide better outcome data.

The Argentine ant persists through unfavorable winters via a mutualism facilitated by a native tree.

Mutualisms and facilitations can fundamentally change the relationship between an organism's realized and fundamental niche. Invasive species may prove particularly suitable models for investigating this relationship as many are dependent on finding new partners for successful establishment. We conducted field-based experiments testing whether a native tree facilitates the successful survival of the invasive Argentine ant, Linepithema humile (Mayr), through unfavorable winter conditions in the southeastern United States. We found Argentine ant nests aggregated around the native loblolly pine, Pinus taeda L., during the winter months. The bark of this tree absorbed enough radiant solar energy to reach temperatures suitable for Argentine ant foraging even when ambient temperatures should have curtailed all foraging. Conversely, foraging ceased when the trunk was shaded. The sun-warmed bark of this tree gave the Argentine ant access to a stable honeydew resource. Argentine ants were not found on or near deciduous trees even though bark temperatures were warm enough to permit Argentine ant foraging on cold winter days. Augmenting deciduous trees with sucrose water through the winter months lead to Argentine ant nests remaining at their base and Argentine ants foraging on the tree. The Argentine ant requires both foraging opportunity and a reliable winter food source to survive through unfavorable winter conditions in the southeastern United States. The loblolly pine provided both of these requirements extending the realized niche of Argentine ants beyond its fundamental niche.

A rare case of adult primary jejunal volvulus.

Jejunal volvulus is a rare and life threatening presentation of intestinal ischaemia. Clinical features, laboratory investigations and plain abdominal films are non-specific and so computed tomography (CT) scanning is useful in reaching a timely diagnosis. Rapid recourse to surgical intervention is typical and life saving. We report a rare case of primary jejunal volvulus which, after diagnosis on emergency CT scanning, was successfully treated by laparotomy and resection of infarcted bowel.

The Argentine ant: challenges in managing an invasive unicolonial pest.

The Argentine ant, Linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damage and disrupting ecosystem processes. Introduced populations of L. humile and those of many other invasive ants tend to be unicolonial, forming expansive, multiqueened supercolonies that dominate native ant communities and challenge control practices in managed habitats. Argentine ant management typically entails the application of residual insecticide liquids, granules, or baits to only a portion of the colony, resulting in fairly rapid reinfestation. We suggest that prevailing control methodologies are incomplete and not compatible with the behavior, nesting habits, and population structure of this ant, and therefore, more aggressive management strategies are required. Successful eradication efforts against other invasive unicolonial ant species can provide useful insights for local-scale L. humile eradication.

Virtual reality simulation objectively differentiates level of carotid stent experience in experienced interventionalists.

OBJECTIVES: Technical proficiency in carotid artery stent (CAS) procedures is paramount to ensure patient safety. If virtual reality (VR) simulation is to be used as a valid means for credentialing physicians for CAS procedures, the assessment parameters must be able to evaluate the performance during CAS and to differentiate level of CAS experience. The aim of this study was to validate assessment parameters of a commercially available VR simulator (VIST, Vascular Interventional Surgical Trainer, Mentice, Gothenburg, Sweden) during a CAS procedure in experienced interventionalists. METHODS: Forty-five interventionalists (cardiologists, radiologists, vascular surgeons) who had performed at least 100 endovascular therapeutic cases, with varying experience in CAS were recruited: groups A, n = 12 (0 CAS procedures), B, n = 12 (1 to 20 CAS), C, n = 10 (21 to 50 CAS) and D, n = 11 (>50 CAS). All subjects performed a standard CAS procedure with a type I arch and were assessed by quantitative (procedure time, amount of contrast given, number of cineloops recorded, fluoroscopic time) and qualitative (clinical parameters and errors) metrics of the simulator. Participants also rated the realism and training potential of the simulator on a scale from 1 (poor) to 5 (excellent). RESULTS: There were significant differences across the four groups A to D for procedure time (medians 20.5 vs 24 vs 19 vs 16 minutes, P = .002) and fluoroscopic time (12.5 vs 13 vs 10 vs 7 minutes, P < .001), respectively. Total numbers of errors recorded by the VR simulator did not achieve statistical significance (P = .209) across the four groups. All subjects rated the simulator highly (median 4) in terms of realism and training potential. CONCLUSIONS: Total time and fluoroscopic time both recorded by a realistic VR simulator differentiate between levels of CAS experience in experienced interventionalists. Error scoring is currently not a valid mode of assessment and needs refinement.