Late abdominal aortic aneurysm rupture after AneuRx repair: a report of three cases.

Rupture due to device failure and/or endoleak is the most feared complication of endoluminal grafting for exclusion of abdominal aortic aneurysm. We present three previously unreported cases of abdominal aortic aneurysm rupture 23 months after AneuRx "repair" and describe the mechanisms of failure and discuss instructive technical aspects of their management.

A method to evaluate the elastic behavior of vascular stents.

PURPOSE: To develop a simple method for determining the elastic behavior of vascular stents. MATERIALS AND METHODS: An experimental apparatus was constructed to determine the elastic behavior of four different vascular stents. Each stent was expanded within an artificial compliant vessel and was subjected to an increasing external pressure. The cross-sectional area of each stent was recorded at incremental changes in pressure. Compliance was estimated from the slope of a linear regression analysis fit to the pressure-area data in the elastic range of deformation. RESULTS: The self-expandable stents were the most compliant, and balloon-expandable stents exhibited the least compliance. The balloon- expandable stents initially deformed in an elastic manner and then yielded irrecoverably at higher pressures. CONCLUSION: A simple method has been devised that allows the elastic behavior of stents to be assessed. Quantification of stent compliance with this method is important as a predictor of stent resistance to compression in vivo.

Effects of vascular stent surface area and hemodynamics on intimal thickening.

PURPOSE: To compare the in vivo response to a new mechanically expandable vascular stent with the response to an existing type of balloon-expandable stent. MATERIALS AND METHODS: Prototype stents were deployed by means of a balloon catheter in the left iliac arteries of four healthy dogs. Palmaz stents were deployed in the contralateral iliac arteries to act as a control, and all stents were explanted after 6 weeks. Arteriography was performed at the time of insertion and before harvest, and pressure gradients were measured across each stent. The stents were then harvested and submitted for histologic examination. RESULTS: The performance of the prototype stent was similar to that of the Palmaz stent with respect to structural integrity, migration, maintenance of intraluminal diameter, ease of deployment, radiopacity, and pressure gradients. Unlike the Palmaz stent, the prototype stent did not foreshorten during expansion. The stents showed a lack of uniformity in terms of the measured luminal area and neointimal accumulation. Neointimal accumulation was more confined to the struts of the prototype stent; the lumen therefore had a fluted appearance. Neointimal accumulation was more broadly distributed around the circumference of the vessel wall of the Palmaz stent. CONCLUSION: In vivo performance of the prototype stent was similar to that of the Palmaz stent. Stent geometry may be an important determinant of neointimal response and resultant long-term patency.

Ischemic nephropathy as an indication for renal artery reconstruction in renovascular hypertension.

The utility of renal revascularization to control hypertension secondary to renal artery occlusive disease is widely recognized. However, revascularization for purposes of renal salvage, although performed successfully in many instances, is a more difficult issue, owing to the higher morbidity and mortality rates associated with operative intervention in an older patient population with significant comorbid conditions. It is therefore imperative to appropriately select patients who may benefit from revascularization, and the aim of our discussion is to aid in this selection process.

Abdominal surgical wound infection is lowered with improved perioperative enterococcus and bacteroides therapy.

Perioperative antibiotics decrease surgical wound infection (SWI) in trauma patients requiring abdominal exploration. This investigation evaluated 24 hours of cefoxitin or ampicillin/sulbactam used for early therapy in such patients. Patients were randomly assigned to one of two treatment groups. The primary endpoint evaluated was SWI, which was defined as purulent drainage or active wound treatment. Five hundred ninety-two patients were evaluated: 283 received ampicillin/sulbactam and 309 received cefoxitin. The incidence of wound infection among the ampicillin/sulbactam patients was 2% and among cefoxitin patients it was 7% (p < 0.004). The cefoxitin patients with colon injuries were analyzed (p < 0.007). The major difference between the two groups was an increased incidence of enterococcal infections in the cefoxitin-treated patients. A single broad-spectrum antibiotic given for 24 hour perioperatively effectively controls SWI. Use of ampicillin/sulbactam results in a significantly lower SWI rate than use of cefoxitin, which may be a result of improved enterococcal and Bacteroides coverage.