SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Aortic aneurysm

169

Takayasu’s arteritis is an inflammatory arteriopathy which involves the aorta and its major branches, causing mainly stenosis of their lumen, though aneurysmal lesions can also occur. A young female with Takayasu’s disease presented to our hospital with acute lung oedema due to severe aortic insufficiency and ascending aorta dilatation. She had already undergone distal ascending aorta and hemiarch replacement due to Standford type A aortic dissection five years ago. The patient had also undergone reconstruction of abdominal arteries' stenoses with extraanatomical bypass. We performed a Bentall procedure with a valved conduit and implantation of the coronary ostia as buttons on the conduit. A mechanical valved graft was used instead of a bioprosthesis, due to possible early degradation of a bioprosthesis. The postoperative course was uneventful and the one year follow-up was normal. Valve-sparing aortic root replacement should be avoided in Takayasu’s arteritis due to high rate of recurrent regurgitation.

Concepts: Cardiology, Heart, Aortic aneurysm, Aortic dissection, Aorta, Ascending aorta, Takayasu's arteritis, Arteritis

122

Abdominal aortic aneurysm (AAA) is a pathological condition characterized by an abnormal, localized dilatation of the lower part of the aorta. Due to a lack of data on the natural history of AAA and risk of death from other cardiovascular diseases attributable to AAA, the true number of AAA-attributable deaths may be higher than currently estimated. This study aims to produce more realistic estimates of the burden of AAA.

Concepts: Death, Heart, Fish, Aortic aneurysm, Aneurysm, Aortic dissection, Aorta, Aneurysm of sinus of Valsalva

28

Valve-sparing aortic root reconstruction (VSRR) is an accepted method to treat patients with aortic root dilation. The role of the VSRR is less well defined for patients with bicuspid aortic valve, severe aortic valve insufficiency, congenital heart defects, and type A aortic dissection. We studied the clinical outcome of patients who underwent VSRR for expanded indications.

Concepts: Aortic aneurysm, Aortic dissection, Aorta, Congenital heart defect, Congenital heart disease, Aortic valve, Aortic insufficiency, Bicuspid aortic valve

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

28

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

28

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

A 60 year-old woman presented with large extensive aneurysms in the thoracic aorta and infra-renal abdominal aorta with a normal segment of visceral aorta in between; the entire right common iliac artery was also aneurysmal. Concurrent endovascular repair of all aneurysmal regions was successfully performed using a left common iliac artery conduit to access the aorta, and multiple stent-grafts; a chimney graft preserved blood flow into the left subclavian artery. There were no features of spinal cord ischaemia despite coil embolisation of the right hypogastric artery. CT angiogram at six months showed patent stent-grafts with no endoleaks. The patient continued to do well at one-year clinical follow-up. Concurrent endovascular repair of thoracic and abdominal aortic aneurysms can be safely and successfully performed when anatomically feasible, and is an attractive alternative to staged or hybrid repair.

Concepts: Abdominal aorta, Aortic aneurysm, Brachiocephalic artery, Aorta, Descending aorta, Arteries of the thorax, Arteries of the abdomen, Common iliac artery

28

To evaluate factors associated with aortic enlargement in patients with a bicuspid aortic valve (BAV) and the impact of isolated aortic valve replacement (AVR).

Concepts: Aortic aneurysm, Aortic valve, Aortic valve replacement, Aortic insufficiency, Bicuspid aortic valve

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