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Concept: Abdominal aortic aneurysm

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-This project by the International Consortium of Vascular Registries, a collaboration of 11 vascular surgical quality registries, was designed to evaluate international variation in the contemporary management of abdominal aortic aneurysm (AAA) with relation to recommended treatment guidelines from the Society for Vascular Surgery and the European Society for Vascular Surgery.

Concepts: Medicine, Aortic aneurysm, Aneurysm, Aortic dissection, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva, General surgery, Vascular surgery

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Thoracic aortic aneurysm is usually a clinically silent disease; timely detection is largely dependent upon identification of clinical markers of thoracic aortic disease (TAD); (bicuspid aortic valve, intracranial aortic aneurysm, bovine aortic arch, or positive family history). Recently, an association of simple renal cysts (SRC) with abdominal aortic aneurysm and aortic dissection was established. The aim of our study was to evaluate the prevalence of SRC in patients with TAD in order to assess whether the presence of SRC can be used as a predictor of TAD.

Concepts: Aortic aneurysm, Aneurysm, Aortic dissection, Aorta, Abdominal aortic aneurysm, Aortic valve, Bicuspid aortic valve, Thoracic aortic aneurysm

106

We sought to describe and analyze discrepancies between sexes in the outcomes of patients hospitalized for ruptured abdominal aortic aneurysms (rAAA) by conducting a retrospective analysis of the Nationwide Inpatient Sample. The review included all adult patients (≥18 years old) hospitalized with a primary diagnosis of rAAA between January 2002 and December 2014. In-hospital mortality differences between females and males were analyzed overall and separately among those receiving endovascular AAA repair (EVAR) or open AAA repair (OAR). In-hospital mortality for females declined from 61.0% in 2002 to 49.0% in 2014 (P for trend <0.001), while mortality for males declined from 48.6% in 2002 to 32.2% in 2014 (P for trend <0.001). Among those receiving EVAR, females were significantly more likely to die in the hospital than males (adjusted odds ratio [OR], 1.44; 95% CI, 1.12-1.84). In addition, the odds of mortality among those receiving OAR were higher for females than males (adjusted OR, 1.14; 95% CI: 1.00-1.31). These data provide evidence that despite overall decreasing trends in mortality for both sexes, females remain at higher risk of death compared with males regardless of surgical repair procedure.

Concepts: Hospital, Aortic aneurysm, Aneurysm, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva

28

Endovascular abdominal aortic aneurysm repair (EVAR) in patients with unfavorable proximal seal zones remains challenging. The purpose of this study was to identify the incidence of proximal extension cuff usage for type I endoleaks in patients with abdominal aortic aneurysms and unfavorable necks treated with the C3 Excluder repositionable endoprosthesis compared with the traditional Excluder stent-graft.

Concepts: Aortic aneurysm, Model theory, Aneurysm, Cerebral aneurysm, Aortic dissection, Aorta, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva

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The long-term success of the endovascular procedure for the treatment of Abdominal Aortic Aneurysms (AAAs ) depends on the secure fixation of the proximal end and the geometry of the stent-graft (SG) device. Variations in SG types can affect proximal fixation and SG hemodynamics. Such hemodynamic variations can have a catastrophic effect on the vascular system and may result from a SG/arterial wall compliance mismatch and the sudden decrease in cross-sectional area at the bifurcation, which may result in decreased distal perfusion, increased pressure wave reflection and increased stress at the interface between the stented and non-stented portion of the vessel. To examine this compliance mismatch, a commercial SG device was tested experimentally under a physiological pressure condition in a silicone AAA model based on computed tomography scans. There was a considerable reduction in compliance of 54% and an increase in the pulse wave velocity of 21%, with a significant amount of the forward pressure wave being reflected. To examine the SG geometrical effects, a commercial bifurcated geometry was compared computationally and experimentally with a geometrical taper in the form of a blended section, which provided a smooth transition from the proximal end to both iliac legs. The sudden contraction of commercial SG at the bifurcation region causes flow separation within the iliac legs, which is known to cause SG occlusion and increased proximal pressure. The blended section along the bifurcation region promotes a greater uniformity of the fluid flow field within the distal legs, especially, during the deceleration phase with reduced boundary layer reversal. In order to reduce the foregoing losses, abrupt changes of cross-section should be avoided. Geometrical tapers could lead to improved clinical outcomes for AAA SGs.

Concepts: Causality, Fundamental physics concepts, Fluid dynamics, Geometry, Aortic aneurysm, Fluid mechanics, Hemodynamics, Abdominal aortic aneurysm

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Purpose: To describe a bailout technique for in situ fenestration of an inadvertently covered internal iliac artery (IIA) associated with endovascular repair of an abdominal aortic aneurysm (AAA). Technique: The procedure is demonstrated in a 76-year-old patient who underwent elective repair of a 5-cm infrarenal AAA using an Excluder endovascular graft 2 years following thoracic aortic stent-graft repair of a chronic type B aortic dissection. A completion angiogram demonstrated unintentional coverage of the left IIA. The iliac limb of the stent-graft was not able to be displaced away from the ostium, so to preserve IIA perfusion in a patient with prior thoracic aortic stent-grafting, a bailout technique was performed using an Outback re-entry device to successfully fenestrate the polytetrafluoroethylene graft material. An iCast balloon-expandable stent was placed across the fenestration creating a patent side branch to maintain patency. Six-year follow-up demonstrates a stable repair. Conclusion: In situ fenestration of a stent-graft overlying the internal iliac artery can be a useful bailout technique when other options are unsuccessful.

Concepts: Aortic aneurysm, Aneurysm, Aortic dissection, Aorta, External iliac artery, Abdominal aortic aneurysm, Internal iliac artery, Vascular surgery

28

Inhibiting the growth of small abdominal aortic aneurysms (AAAs) is a clinically valuable goal and fills an important therapeutic void. Based on studies in animals and humans, inhibition of the activity of elastolytic matrix metalloproteinases (MMPs) has the potential to slow AAA expansion and limit morbidity and the need for surgery. Previous attempts to make use of the synthetic MMP inhibitors in the treatment of chronic conditions have been limited by intolerable side effects. The limited-spectrum synthetic MMP inhibitor, XL784, was well tolerated and devoid of side-effects associated with other nonspecific MMP inhibitors in phase I studies. We hypothesized that clinically relevant doses of XL784 would be effective at inhibiting aneurysm development in a mouse model.

Concepts: Aortic aneurysm, Inhibitor, Matrix metalloproteinase, Xanthine oxidase inhibitor, Abdominal aortic aneurysm

28

A 74-year-old man presented with back pain and collapse. A ruptured infrarenal abdominal aortic aneurysm was successfully managed by endovascular aneurysm repair. Postoperatively, he developed gastric outlet obstruction owing to duodenal compression from the unevacuated retroperitoneal haematoma. In the absence of abdominal compartment syndrome, conservative management with gastric decompression and parenteral nutrition led to a full recovery.

Concepts: Stomach, Aortic aneurysm, Aneurysm, Aortic dissection, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva, Digestion, Abdominal cavity

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PURPOSE: Neutrophils have been shown to be involved in all stages of human and experimental abdominal aortic aneurysm (AAA) development. The initial processes of neutrophil rolling and trapping in the intraluminal thrombus (ILT) are mediated mainly by P-selectin expressed by activated platelets. In the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the ILT induced by repeated episodes of weak bacteremia. METHODS: Sixty Lewis rats with experimental AAAs, developed from decellularized aortic xenografts, were divided into four groups. Two groups were used as controls: group fucoidan control (FC) was treated with 200 mg of fucoidan (F) delivered by 2 mL, 4-week osmotic pumps placed intraperitoneally before closing the abdomen, and group C received saline instead of fucoidan. Two more groups were injected weekly with Porphyromonas gingivalis (P. gingivalis [Pg]): group F+Pg received 200 mg of intraperitoneal fucoidan and group Pg received saline. AAAs were harvested after 4 weeks and peripheral blood was sampled at that time. Cell-free DNA (cf-DNA) and myeloperoxydase (MPO) antigen concentrations were determined in plasma and in AAA-conditioned media. Histology and P-selectin immunostaining were performed on AAA tissue samples. RESULTS: Comparing rats injected with Pg, those receiving fucoidan presented reduced aneurysmal diameter. Histologic analysis of AAAs showed that fucoidan reduced the ILT thickness in Pg-injected rats, with fewer trapped neutrophils, and with signs of a healing process, as observed in control group C. Immunohistological analysis revealed a substantial decrease in P-selectin immunostaining at the luminal surface of aneurysms in fucoidan-treated rats compared to the other groups, suggesting an interaction between fucoidan and P-selectin. A significant decrease in MPO concentrations in both plasma and conditioned medium was induced by fucoidan treatment in Pg-injected rats, reflecting a pacification of the ILT biological activity. This effect was associated with a reduction in neutrophil activation and apoptosis, reflected by a significant decrease in cf-DNA concentration in both plasma and conditioned medium of fucoidan-treated rats. CONCLUSIONS: Our results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration by decreasing neutrophil activation in the ILT enhanced by weak pathogen contamination. This effect seems to be related to its interaction with P-selectin, which may decrease the trapping of neutrophils into the ILT. Fucoidan could represent a therapeutic option in AAAs to decrease the neutrophil activation involved in the degenerative process of aneurysmal expansion and rupture.

Concepts: Blood, Histology, Aortic aneurysm, Aneurysm, Aortic dissection, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva, Porphyromonas gingivalis

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Arterial complications are common in vascular type Ehlers-Danlos syndrome (EDS), accounting for 66% of first complications. Several cases in the literature have documented acute compartment syndrome (ACS) following vascular rupture in vascular type EDS. Other disorders of connective tissue have also demonstrated vascular fragility, leading to arterial aneurysm and rupture, but there have been no documented cases of ACS. Here, we report on a female patient with a history of recurrent compartment syndrome who exhibits some clinical findings seen in hypermobile and vascular EDS; however she does not meet clinical and molecular diagnostic criteria for either of them. We further review the literature on ACS in heritable connective tissue disorders and suggest that compartment syndrome may rarely complicate other heritable disorders of connective tissue. © 2013 Wiley Periodicals, Inc.

Concepts: Blood, Collagen, Syndromes, Marfan syndrome, Abdominal aortic aneurysm, Connective tissue, Ehlers-Danlos syndrome, Compartment syndrome