Computed tomography virtual intravascular endoscopy in the evaluation of fenestrated stent graft repair of abdominal aortic aneurysms.

Background: This study aimed to investigate the diagnostic value of computed tomography virtual intravascular endoscopy (VIE) in the follow-up of patients with abdominal aortic aneurysm (AAA) treated with fenestrated stent grafts.

Methods: A total of 19 patients (17 males and 2 females; mean age: 75 years) with AAA undergoing fenestrated stent grafts were retrospectively studied. Pre- and post-fenestration computed tomography data were reconstructed for the generation of VIE images of aortic ostia and fenestrated stents and compared with two-dimensional axial and multiplanar reformation (MPR) images.

Experimental measurement and mathematical modeling of pulsatile forces on a symmetric, bifurcated endoluminal stent graft model.

The objective of this study was to measure the pulsatile forces acting on a symmetric, bifurcated endoluminal stent graft to validate a computational fluid dynamics (CFD) and analytic model so that they can be used for various graft dimensions. We used a load cell to measure the force owing to the movement of an acrylic model of a bifurcated stent graft under pulsatile flow. This was then simulated with a CFD and analytic model.

A laparoscopic endovascular aortobifemoral conduit that can be retained as a long-term bypass: a solution for patients with inadequate iliac access.

Purpose: To present a laparoscopic technique for placing a partially stented aortobifemoral (ABF) conduit that can be used for more proximal endovascular manipulations and then be retained as a permanent bypass of occlusive iliac disease.

Technique: Ethical approval was obtained to use a fresh frozen cadaver. The left common iliac artery, distal aorta, and proximal right common iliac artery were dissected laparoscopically.

Multislice CT angiography in the follow-up of fenestrated endovascular grafts: effect of slice thickness on 2D and 3D visualization of the fenestration stents.

Purpose: To investigate the effect of multislice computed tomography (CT) protocols on the visualization of target vessel stents in patients with abdominal aortic aneurysm (AAA) treated with fenestrated endovascular grafts.

Methods: Twenty-one patients (19 men; mean age 75 years, range 63-86) undergoing fenestrated endovascular repair of AAA were retrospectively studied. Multislice CT angiography was performed with several protocols, and the section thicknesses used in each were compared to identify any relationship between slice thickness and target vessel stents visualized on 2-dimensional (2D) axial, multiplanar reformatted (MPR), and 3-dimensional (3D) virtual intravascular endoscopy (VIE) images.

Modeling of antegrade and retrograde flow into a branch artery of the aorta: implications for endovascular stent-grafting and extra-anatomical visceral bypass.

Purpose: To compare antegrade and retrograde flow characteristics in a branch of a conduit under typical pulsatile pressure and flows, seeking an answer to the question: "Does it matter whether inflow to a branch vessel is antegrade or retrograde?"

Methods: A model was built to simulate an abdominal aorta with a branch designed to approximate a typical renal artery. Experiments were conducted to measure the flow rates from 40- and 200-mm-long inflow conduit tubes simulating a branch with antegrade and retrograde inflow configurations. For the base case with a flush origin of the branch, the pressure difference between the main conduit and branch vessel was adjusted so that the average branch flow rate was 1.

CT virtual intravascular endoscopy in the visualization of fenestrated stent-grafts.

Purpose: To report the diagnostic value of computed tomographic (CT) virtual intravascular endoscopy (VIE) in the assessment of patients with abdominal aortic aneurysm (AAA) treated with fenestrated endovascular grafts.

Methods: Eight patients (7 men; mean age 76 years, range 70-82) with AAAs unsuitable for open surgery or conventional endovascular repair had fenestrated endovascular grafts implanted. Both pre- and post-fenestration multislice CT data were used to generate VIE images of the visceral artery ostia and the side branch fenestrated stents.

Large iliac arteries: a high-risk group for endovascular aortic aneurysm repair.

Purpose: To examine if the presence of large iliac arteries is a potential risk factor for the development of a type Ib endoleak (iliac sealing zone) or need for iliac artery-related secondary intervention in patients undergoing endovascular abdominal aortic aneurysm repair.

Methods: The medical notes and all preoperative and postoperative plain abdominal radiographs and computer tomographic scans were reviewed for a consecutive series of 100 patients (89 men; mean age 75 years, range 56-91) with large iliac arteries (mean 19.7 mm, range 16-22) who had Zenith endovascular stent-grafts inserted for management of aortoiliac aneurysmal disease from January 1999 until September 2002.

Treatment of infrarenal abdominal aortic aneurysms with oversized (36-mm) Zenith endografts.

Purpose: To evaluate the outcome of treating infrarenal abdominal aortic aneurysms with unfavorable necks using the 36-mm Zenith endograft.

Methods: The indication for use of the 36-mm endograft for infrarenal aortic aneurysm was a minimum 20-mm-long sealing zone and a diameter >28 mm at any point but <34 mm, varying more than 3 mm in contour. A series of 67 patients (64 men; mean age 76.

Short to midterm outcomes of fenestrated endovascular grafts in the treatment of abdominal aortic aneurysms: a systematic review.

Purpose: To perform a systematic review of the short to midterm outcomes of fenestrated endovascular grafts in patients with abdominal aortic aneurysms (AAA).

Methods: A search of PubMed and Medline databases for English-language literature was performed to find studies published between 1999 and 2006. Studies investigating the short to midterm results of fenestrated endovascular grafts for AAA were analyzed for clinical outcomes and postprocedural complications.

A laparoscopic access technique for endovascular procedures: surgeon training in an animal model.

Purpose: To present a laparoscopic technique for placing a transperitoneal conduit in the common iliac artery (CIA) or distal aorta to circumvent stenosed or occluded iliac systems and to assess the success of this laparoscopic access in a live animal model.

Technique: A porcine model was used owing to similarities in anatomy and size of the pig aorta to the human common iliac artery (CIA). Ethical approval was obtained, and the technique was developed in 8 animals under general anesthesia.

Outcomes of fenestrated endografts in the treatment of abdominal aortic aneurysm in Western Australia (1997-2004).

Purpose: To describe a 7-year experience with abdominal aortic aneurysm (AAA) repair using fenestrated Zenith endovascular endografts.

Methods: Six endovascular surgeons from 7 medical centers in Perth, Western Australia, contributed data to this retrospective study of 58 AAA patients (51 men; mean age 75.5+/-8.

Movement and dislocation of modular stent-grafts due to pulsatile flow and the pressure difference between the stent-graft and the aneurysm sac.

Purpose: To investigate the stability and movement of modular aortic stent-grafts subjected to oscillating forces from pulsatile blood flow, with particular reference to the thoracic aorta.

Methods: Analytical mathematical modeling was used to understand the forces on modular grafts. In a benchtop experiment, a transparent acrylic box was filled with water to mimic an aneurysm.

Infected endoluminal stent-graft: implications for endotension, late endoleaks, and prophylactic antibiotics.

Purpose: To retrospectively review a case of stent-graft infection that presented as continued aneurysm expansion after endoluminal repair.

Case Report: A 75-year-old man with an asymptomatic 6.1-cm abdominal aortic aneurysm (AAA) was treated with a Talent stent-graft, which was complicated by postimplantation syndrome.

Experimental force measurements on a bifurcated endoluminal stent graft model: comparison with theory.

The goal of this study was to experimentally validate a steady-state mathematical model, which can be used to compute the forces acting on a bifurcated endoluminal stent graft. To accomplish this task, an acrylic model of a bifurcated graft was used for the force measurements. The graft model was connected to the inlet piping with a flexible rubber membrane that allowed the graft model to move.

In situ stent-graft fenestration to preserve the left subclavian artery.

Purpose: To report our first clinical application of a new technique for in situ fenestration of a thoracic stent-graft.

Case Report: After completing a series of in vitro and in vivo experiments, in situ stent-graft fenestration was employed during endograft repair of a saccular thoracic aortic aneurysm in a 77-year-old woman. Because the stent-graft would have covered the left subclavian artery ostium, a modified Zenith TX1 thoracic stent-graft was deployed then fenestrated transluminally using a guidewire followed by serial cutting balloons, which created a fenestration over the LSA sufficiently large to accommodate a Jomed covered stent on an 8-mm balloon.

Follow-up after endovascular aortic aneurysm repair: the plain radiograph has an essential role in surveillance.

Periodic follow-up is mandatory for patients with aortic stent-grafts. Central to surveillance is the establishment of a baseline against which changes can be detected. Computed tomography (CT) has been the benchmark of follow-up imaging for endografts, but comparison of serial AP and lateral plain radiographs will detect structural alterations that can be missed on CT scans.

Plain radiographic surveillance of abdominal aortic stent-grafts: the Liverpool/Perth protocol.

Purpose: To present a protocol for plain radiographic surveillance of abdominal aortic stent-grafts that addresses the main variables in need of standardization: (1) patient position, (2) radiographic centering point, and (3) focus-to-film distance.

Technique: Our policy is to perform baseline anteroposterior and lateral films following endoluminal grafting and repeat the studies annually. These are the most important films to assess migration and component separation; supplementary right and left posterior oblique radiographs may help identify wireform fractures.

Retrograde fenestration of endoluminal grafts from target vessels: feasibility, technique, and potential usage.

Purpose: To report initial experiments involving a new method for percutaneous intraprocedural stent-graft fenestration from the target vessel.

Technique: In bench and canine models, the fabric of an implanted Zenith endograft was punctured easily using the stiff end of a coronary 0.014-inch guidewire delivered through the target vessel (e.

Endoluminal repair of mycotic thoracic aneurysms.

Purpose: To report a series of endoluminally repaired mycotic thoracic aneurysms.

Case Reports: Four patients with presumed mycotic aneurysms of the thoracic aorta were treated with endovascular grafts owing to overly high risk for open repair. All aneurysms were successfully excluded at the initial intervention.

Suprarenal fixation: effect on blood flow of an endoluminal stent wire across an arterial orifice.

Purpose: To investigate what effect, if any, the presence of a stent wire in front of a renal artery has on the volume flow rate of blood through the renal artery.

Methods: Experimental, numerical, and analytical modeling methods were used to test 4 separate stent wire configurations: a stent wire across the center of an artery orifice, an off-center wire placed at one-quarter the arterial diameter, a V-shaped wire with its vertex at the center, and 2 stent wires at one-third-diameter spacing.

Results: For all the configurations studied, the presence of stent wires has a minimal effect on the blood flow rate into an artery of >/=3-mm diameter, with most flow rates decreasing by around 1%.

The effect of age on serum creatinine levels in an aging population: relevance to vascular surgery.

Background And Aim: Serum creatinine is commonly used to assess and monitor renal function in the management of abdominal aortic aneurysm with endoluminal grafting, and for intervention of renal artery occlusive disease. The majority of patients selected for these procedures are elderly and serum creatinine is used post-operatively to monitor renal function. There is a need to adjust the serum creatinine concentration for age to determine the changes that might be due to the procedure: especially with endoluminal grafting using transrenal manipulation and fixation, and procedures involving interventions directly on the renal arteries.