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Purpose: To assess the relationship between sigmoid colonic perfusion, endotoxemia, and cytokine generation in patients undergoing elective open repair (OR) or endovascular repair (EVR) of infrarenal abdominal aortic aneurysms (AAA)., Methods: Ten patients (9 males; average age 67.6 +/- 2.5 years, mean aneurysm diameter 6.9 +/- 0.6 cm) undergoing OR were compared to 10 patients (all males; average age 70.3 +/- 2.6 years, mean aneurysm diameter 6.5 +/- 0.5 cm) whose repair was performed using the EVR technique. The partial pressure of the carbon dioxide gap (PCO2gap = tissue PCO2 - arterial PCO2) of the sigmoid colonic mucosa was measured using a silicone tonometer to evaluate bowel perfusion. Blood samples were collected into pyrogen-free heparinized tubes for quantification of plasma concentrations of endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) before, during, and after aortic repair., Results: Patients in the OR group had a significantly greater increase in PCO2gap, suggesting a greater degree of bowel ischemia compared to the EVR group. This was associated with significantly greater postoperative concentrations of endotoxin, TNF-alpha, and IL-6 in the OR group. A significant correlation was found between PCO2gap, IL-6, and postoperative core temperature., Conclusions: The results suggest that the degree of bowel ischemia, endotoxemia, and cytokine generation following elective infrarenal AAA reconstruction may be reduced if the endovascular technique is used instead of conventional surgery.

Purpose: To report a technique that might decrease the incidence of lumbar artery endoleaks following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs)., Methods: Ninety-three patients (86 males, median age 72 years, range 56 to 88) undergoing EVR with the aortomonoiliac technique were entered into a study to detect and then occlude patent side branches before completion of the endografting procedure. Prior to deploying the iliac occluder, an aneurysmogram was performed to detect patent aortic side branches. If these side branches were found, an absorbable gelatin sponge was inserted into the aneurysm sac via the occluder introducer sheath. The patients were followed with contrast-enhanced spiral computed tomography (CT) at 1 week and 3, 6, and 12 months to detect the presence of endoleaks., Results: Forty-eight (52%) patients demonstrated patent side branches that were occluded by the insertion of gelatin sponges into the aneurysm sac. The remaining 45 patients without evidence of side branch flow were untreated. Ten (10.7%) patients died in the perioperative period, and 15 (16.1%) primary endoleaks (13 proximal, 2 distal) were detected. This left 68 (73.1%) patients for follow-up, 33 (48.5%) of whom had patent branch vessels treated with the thrombogenic sponge. The median follow-up was 4 months (range 1 to 17), during which time no side branch endoleak was detected on surveillance CT scans in any of the 68 patients, which included all patients treated with the thrombogenic sponge technique and those in whom no patent side branches had been identified., Conclusions: We have demonstrated a safe and reliable method of preventing lumbar artery endoleaks following endovascular AAA repair.

Purpose: To present the perioperative and late mortality following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs)., Methods: Data were collected prospectively on 221 patients undergoing AAA EVR over a 4-year period (median 5-month follow-up). Patients were classified preoperatively as high risk with at least 1 of these features: serum creatinine > 150 micromol/L, ischemic heart disease or poor left ventricular function, respiratory function < 50% of predicted normal, ruptured or symptomatic AAA, contraindication to or failed open repair, and age > 80 years., Results: One hundred forty (63.3%) patients were classified as high risk, the most common criterion being cardiac disease (n = 96, 68.6%). There were 25 (11.3%) deaths in the 30-day perioperative period, 22 (15.7%) in the high-risk group compared to 3 (3.7%) in the acceptable-risk group (p = 0.02). The most common causes of perioperative death were multisystem organ failure and myocardial infarction. A further 21 (9.5%) late deaths occurred, 16 (11.4%) in the high-risk group and 5 (6.2%) in the acceptable-risk group (p > 0.1)., Conclusions: The mortality of patients at acceptable risk undergoing EVR compares with the best published series for conventional open AAA repair. The perioperative and late mortality in the high-risk patients are substantially higher.

Objective: The purpose of this study was to detect any change in the proximal neck diameter after endovascular repair of abdominal aortic aneurysm., Methods: The study was performed in a teaching hospital with an endovascular program on 112 patients who had undergone endovascular repair of abdominal aortic aneurysm. The interventions were pre-endovascular and postendovascular repair of abdominal aortic aneurysms with contrast-enhanced, spiral computerized tomography, and the main outcome measures were change in aortic proximal neck diameter, change in maximum aortic diameter, presence of endoleaks, and change in length from lowest renal artery to aortic bifurcation., Results: The median anterior-posterior and transverse diameter decreased from 63.5 mm before surgery to 50.4 and 54.5 mm, respectively, after surgery in a period of 4 years. This trend in reduction in maximum diameter was not seen in the patients with endoleaks. There was no significant change in the proximal neck diameters when measured at 5-mm intervals after endovascular repair. There was also no significant change in the aortic length after endovascular repair., Conclusion: We have not demonstrated any evidence for proximal neck dilatation after endovascular repair of abdominal aortic aneurysm.

Purpose: To investigate the renal complications associated with endovascular repair of abdominal aortic aneurysms (AAAs)., Methods: Data were prospectively collected on 164 AAA patients (154 males; median age 72 years; interquartile range 51 to 88) undergoing endovascular grafting. Any history of renal failure and diabetes mellitus was recorded. Serum urea and creatinine levels were measured preoperatively and at regular intervals postoperatively. Renal impairment was defined as serum creatinine > 130 micromol/L., Results: There were no significant differences in pre- and 1-day postoperative serum urea and creatinine levels. Among 15 (9.1%) patients with preoperative renal failure, 7 (47%) died, 4 (27%) in the perioperative period. Of the 149 patients with normal renal function preoperatively, 4 (2.7%) developed renal failure as part of multisystem organ failure. Another 9 (6.2%) developed significant postoperative elevations (> 20%) in their creatinine levels compared to baseline; 4 of these patients died, 2 in the perioperative period. There was no significant difference in the median dose of intravascular contrast used for those patients that did and did not have a deterioration in their renal function (250 mL versus 300 mL)., Conclusions: In this study, approximately 6% of patients with normal preoperative renal function who undergo endovascular AAA repair develop renal dysfunction. For patients with preoperative renal impairment, the perioperative mortality rate is high, 27%, following endovascular aortic aneurysm repair.

Objective: Endovascular repair (EVR) of abdominal aortic aneurysm (AAA) has many potential advantages, one of which may be reduced blood product requirements. The aim of this study was to compare the current blood product usage in our unit for three types of elective operation: EVR of AAA, open AAA repair and femorofemoral crossover grafts., Design: Prospective data analysis with historical controls., Materials: One-hundred and thirty-two patients undergoing elective EVR of AAA, 35 patients undergoing elective open repair of AAA and 37 patients having femorofemoral crossover grafts., Methods: Data was collected on the blood product requirements of patients having EVR of AAA, with open AAA repair and femorofemoral crossover graft providing historical controls., Results: There was no difference in the haematological parameters preoperatively between the three groups but postoperatively patients having EVR had a slightly lower haemoglobin than the open group (10.6 g/dl vs. 10.85 g/dl, p = 0.015). The number of patients who received blood transfusion in the EVR group was 82/132 (62%) and the open group 27/35 (77%), p = 0.4., Conclusion: Patients undergoing EVR of AAA require blood transfusion in the same numbers when compared to those undergoing open repair.

Objective: The following procedures are the 3 main methods of endovascular repair (EVR) of abdominal aortic aneurysms (AAA): aorto-aortic bypass grafting, bifurcated bypass grafting, and aorta uni-iliac grafts. The latter method has the potential disadvantage of requiring an extra anatomic graft (ie, a femorofemoral crossover bypass graft) to maintain contralateral pelvic and limb perfusion. The aim of this study was to assess the complications associated with the femorofemoral crossover bypass graft after aorta uni-iliac EVR of AAA., Method: A prospective review was conducted of the complications attributable to the femorofemoral crossover bypass graft in 136 patients who underwent EVR of AAA with an aorta uni-iliac device., Results: During a median follow-up of 7 months (range, 0 to 36 months), 4 patients had superficial wound infections that required antibiotic treatment and 2 patients had bypass graft infections. Nine hematomas developed: 7 (5%) groin hematomas (6 in patients with Dacron bypass grafts), 1 scrotal hematoma, and 1 perigraft hematoma. One bypass graft thrombus developed., Conclusion: The femorofemoral crossover bypass graft is a safe and a durable component of EVR of AAA with an aorta uni-iliac device. The results are similar to those with bifurcated devices.

Objective: An endoleak is defined as the presence of contrast medium within the aneurysm sac on post-operative contrast-enhanced computed tomography scans (CT) in patients following endovascular repair (EVR) of abdominal aortic aneurysms (AAA). The aim of this study was to correlate the incidence of endoleaks with the presence of patent lumbar (LA) and inferior mesenteric arteries (IMA) as seen on pre-operative angiography., Design, Materials and Methods: Forty-seven patients were assessed pre-operatively by both CT and angiography by a blinded radiologist prior to EVR of AAA. The number and size of patent vessels was recorded and correlated with the incidence of LA or IMA endoleaks on follow-up CT. Patent lumbar vessels were scored: 1 = small, 2 = medium, 3 = large., Results: Five patients were noted to have patent IMA on pre-operative angiography but none developed an endoleak. In this series, five patients had an endoleak due to a patent LA. The median score for patients with no endoleak was 1 (0-9) and for those with a lumbar endoleak 2 (0-5) (P = 0.26, Mann-Whitney U-test). The number of patent lumbar arteries was not predictive of a subsequent endoleak. Two out of nine (22 %) patients with large patent LA subsequently developed an endoleak. If a policy of pre-operative embolization on the basis of large patent LA had been adopted, seven patients would have had an unnecessary invasive procedure., Conclusion: Pre-operative angiography to look for patent LA and IMAs is not required in patients undergoing EVR or AAA.