Accurate assessment of abdominal aortic aneurysm with intravascular ultrasound scanning: validation with computed tomographic angiography.
(17/3079)
PURPOSE: The purpose of this study was to assess the accuracy of intravascular ultrasound (IVUS) parameters of abdominal aortic aneurysm, used for endovascular grafting, in comparison with computed tomographic angiography (CTA). METHODS: This study was designed as a descriptive study. Between March 1997 and March 1998, 16 patients with abdominal aortic aneurysms were studied with angiography, IVUS (12.5 MHz), and CTA. The length of the aneurysm and the length and lumen diameter of the proximal and distal neck obtained with IVUS were compared with the data obtained with CTA. The measurements with IVUS were repeated by a second observer to assess the reproducibility. Tomographic IVUS images were reconstructed into a longitudinal format. RESULTS: IVUS results identified 31 of 32 renal arteries and four of five accessory renal arteries. A comparison of the length measurements of the aneurysm and the proximal and distal neck obtained with IVUS and CTA revealed a correlation of 0.99 (P <.001), with a coefficient of variation of 9%. IVUS results tended to underestimate the length as compared with the CTA results (0.48 +/- 0.52 cm; P <.001). A comparison of the lumen diameter measurements of the proximal and distal neck derived from IVUS and CTA showed a correlation of 0.93 (P <.001), with a coefficient of variation of 9%. IVUS results tended to underestimate aneurysm neck diameter as compared with CTA results (0.68 +/- 1.76 mm; P =.006). Interobserver agreement of IVUS length and diameter measurements showed a good correlation (r = 1.0; P <.001), with coefficients of variation of 3% and 2%, respectively, and no significant differences (0.0 +/- 0.16 cm and 0.06 +/- 0.36 mm, respectively). The longitudinal IVUS images displayed the important vascular structures and improved the spatial insight in aneurysmal anatomy. CONCLUSION: Intravascular ultrasound scanning results provided accurate and reproducible measurements of abdominal aortic aneurysm. The longitudinal reconstruction of IVUS images provided additional knowledge on the anatomy of the aneurysm and its proximal and distal neck. (+info)
Cytokine and fibrinogen response in patients undergoing open abdominal aortic aneurysm surgery.
(18/3079)
OBJECTIVES: To assess whether open abdominal aortic aneurysm (AAA) surgery influences cytokines and fibrinogen. METHODS: Twenty-three consecutive patients operated on for AAA were compared to 11 operated controls and 20 age-matched controls. Cubital blood was sampled pre-, intra- and postoperatively and femoral blood also sampled intraoperatively. RESULTS: Preoperatively, interleukin (Il)-6 was elevated in AAA patients. During aortic clamping, Il-6, Il-10 and monocyte chemoattractant protein-1 (MCP-1) increased significantly (p < 0.001, p < 0.01 and p < 0.05 respectively) while soluble interleukin-2 receptor (sIl-2R) and fibrinogen decreased significantly (p < 0.001 for both). After aortic declamping, Il-6, Il-10 and MCP-1 had further significant increases compared with levels during aortic clamping while sIl-2R had a further non-significant and fibrinogen a significant decrease (p < 0.05 in cubital and p < 0.001 in femoral blood). One week postoperatively Il-6, Il-10 and MCP-1 had all decreased but were still significantly elevated compared with baseline values while sIl-2R and fibrinogen showed an increase in comparison with baseline (p < 0.001 for both). Intraoperative levels of Il-6 and Il-10 showed a significant co-variation with the magnitude of operative trauma. CONCLUSIONS: These data indicate that open AAA surgery induces a profound inflammatory and coagulative response which persists at one week postoperatively. (+info)
Cardiovascular and catecholamine responses during endovascular and conventional abdominal aortic aneurysm repair.
(19/3079)
OBJECTIVES: To compare changes in plasma catecholamines, acid-base status and cardiovascular dynamics in patients undergoing endovascular or conventional infrarenal abdominal aortic aneurysm (AAA) repair under standard general anaesthesia. DESIGN: Prospective cohort study. MATERIALS: 30 patients scheduled for elective infrarenal AAA repair. METHODS: Plasma epinephrine and norepinephrine concentrations, acid-base status and cardiovascular measurement were compared before surgery, and 5 min after aortic clamping and clamp release (conventional group) or occlusion and release (endovascular group) in patients undergoing endovascular (n = 15) or conventional AAA repair (n = 15). RESULTS: Arterial pH (p < 0.005) and base deficit (p < 0.05) increased, and plasma bicarbonate decreased (p < 0.005) during aortic cross-clamping in the conventional group. pH decreased further (p < 0.005), and base deficit and pCO2 increased (both p < 0.005) after clamp release. These changes were significantly greater than during endovascular repair, in whom within-group changes were not statistically significant. Values were similar in the two groups 30 min after reperfusion. Plasma epinephrine concentrations increased during conventional surgery (p < 0.05) and were greater than in the endovascular group (p < 0.05). Plasma norepinephrine concentrations increased during surgery in both groups but the changes were not statistically significant. CONCLUSIONS: Plasma catecholamine concentrations, changes in cardiovascular variables and acid-base status were increased during conventional compared with endovascular AAA repair. (+info)
Late survival after abdominal aortic aneurysm repair.
(20/3079)
OBJECTIVES: This study was undertaken to determine the late survival of patients operated successfully for abdominal aortic aneurysm (AAA) repair, to compare survival data with that of the age- and sex-matched general population, to identify the causes of late death, and to determine the factors influencing late survival. MATERIALS AND METHODS: A total of 187 consecutive patients underwent elective surgical AAA repair between January 1987 and December 1991. There were 11 postoperative deaths (early mortality rate 5.9%). The remaining 176 patients formed the basis of this cohort-based retrospective study. Six patients (3.4%) were lost to follow-up. Mean follow-up was 71 months. RESULTS: A total of 70 patients (39.8%) died during the study period. Coronary artery disease (CAD) and cancer were the two main causes. The survival rate at five years (71.6%) was lower than that of the sex- and age-matched general population (90.6%). Neither arterial hypertension nor CAD had any influence on late survival. In contrast, age and chronic renal failure were predictive variables of late survival. CONCLUSIONS: The life expectancy of patients who undergo successful AAA repair is not as good as that of the age- and sex-matched general population. Late survival depends on the patients' age at the time of surgery and the existence of preoperative chronic renal failure. (+info)
The importance of surgeon volume and training in outcomes for vascular surgical procedures.
(21/3079)
PURPOSE: Mortality and morbidity rates after vascular surgical procedures have been related to hospital volume. Hospitals in which greater volumes of vascular surgical procedures are performed tend to have statistically lower mortality rates than those hospitals in which fewer procedures are performed. Only a few studies have directly assessed the impact of the surgeon's volume on outcome. Therefore, the purpose of this study was to review a large state data set to determine the impact of surgeon volume on outcome after carotid endarterectomy (CEA), lower extremity bypass grafting (LEAB), and abdominal aortic aneurysm repair (AAA). METHODS: The Florida Agency for Health Care Administration state admission data from 1992 to 1996 were obtained. The data included all nonfederal hospital admissions. Frequencies were calculated from first-listed International Classification of Diseases-9 codes. Multiple logistic regression was used to test the significance on outcome of surgeon volume, American Board of Surgery certification for added qualifications in general vascular surgery, hospital size, hospital volume, patient age, and gender. RESULTS: During this interval, there were 31,172 LEABs, 45,744 CEAs, and 13,415 AAAs performed. The in-hospital mortality rate increased with age. A doubling of surgeon volume was associated with a 4% reduction in risk for adverse outcome for CEA (P =.006), an 8% reduction for LEAB, and an 11% reduction for AAA ( P =.0002). However, although hospital volume was significant in predicting better outcomes for CEA and AAA procedures, it was not associated with better outcomes for LEAB. Certification for added qualifications in general vascular surgery was a significant predictor of better outcomes for CEA and AAA. Certified vascular surgeons had a 15% lower risk rate of death or complications after CEA (P =.002) and a 24% lower risk rate of a similar outcome after AAA (P =.009). However, for LEAB, certification was not significant. CONCLUSION: Surgeon volume and certification are significantly related to better patient outcomes for patients who undergo CEA and AAA. In addition, surgeons with high volumes demonstrated consistently lower mortality and morbidity rates than did surgeons with low volumes. Hospital volume for a given procedure also is correlated with better outcomes. (+info)
Infrarenal aortic surgery with a 3-day hospital stay: A report on success with a clinical pathway.
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PURPOSE: This paper reports on an experience with a clinical pathway for elective infrarenal aortic surgery (AS) that targeted hospital discharge on postoperative day (POD) 3. The pathway incorporated early feeding, early ambulation, and selective use of the intensive care unit (ICU). METHODS: A review of 50 consecutive hospital discharges after AS (aneurysm repair and aortofemoral bypass grafting) by a single surgeon performed from April 1996 through June 1998 with this clinical pathway is reported. The data collected included morbidity rate, mortality rate, length of stay (LOS), and number of hospital readmissions. RESULTS: The average LOS for all patients was 3.0 days. Only six patients (12%) were admitted to the ICU. Discharge on POD 3 was achieved in 80% of the group (40 of 50), and increasing experience improved compliance, with 92% of the most recent 25 patients (23 of 25) being discharged by POD 3. Eleven of these 25 patients (44%) were discharged on POD 2. No patient was readmitted to the hospital within a 30-day period after discharge. There was no mortality after AS during this period. CONCLUSION: Factors that limit the discharge of patients recovering from AS include the ability to ambulate independently and to tolerate a diet. Ambulation and feeding on POD 1 were well tolerated by most patients, which shortened the period of hospitalization. Admission to the ICU was infrequently required when a monitored surgical step-down unit was available. Discharge by POD 3 for AS has been proven to be routinely achievable, safe, and well accepted by patients and to reduce the cost of hospitalization. (+info)
Feasibility of endovascular repair of abdominal aortic aneurysms with local anesthesia with intravenous sedation.
(23/3079)
PURPOSE: Local anesthesia has been shown to reduce cardiopulmonary mortality and morbidity rates in patients who undergo selected peripheral vascular procedures. The efforts to treat abdominal aortic aneurysms (AAAs) with endovascular techniques have largely been driven by the desire to reduce the mortality and morbidity rates as compared with those associated with open aneurysm repair. Early results have indicated a modest degree of success in this goal. The purpose of this study was to investigate the feasibility of endovascular repair of AAAs with local anesthesia. METHODS: During a 14-month period, 47 patients underwent endovascular repair of infrarenal AAAs with local anesthesia that was supplemented with intravenous sedation. Anesthetic monitoring was selective on the basis of comorbidities. The patient ages ranged from 48 to 93 years (average age, 74.4 +/- 9.8 years). Of the 47 patients, 55% had significant coronary artery disease, 30% had significant chronic obstructive pulmonary disease, and 13% had diabetes. The average anesthesia grade was 3.1, with 30% of the patients having an average anesthesia grade of 4. The mean aortic aneurysm diameter was 5.77 cm (range, 4.5 to 12.0 cm). All the implanted grafts were bifurcated in design. RESULTS: Endovascular repair of the infrarenal AAA was successful for all 47 patients. One patient required the conversion to general anesthesia to facilitate the repair of an injured external iliac artery via a retroperitoneal approach. The operative mortality rate was 0. No patient had a myocardial infarction or had other cardiopulmonary complications develop in the perioperative period. The average operative time was 170 minutes, and the average blood loss was 623 mL (range, 100 to 2500 mL). The fluid requirements averaged 2491 mL. Of the 47 patients, 46 (98%) tolerated oral intake and were ambulatory within 24 hours of graft implantation. The patients were discharged from the hospital an average of 2.13 days after the procedure, with 87% of the patients discharged less than 48 hours after the graft implantation. Furthermore, at least 30% of the patients could have been discharged on the first postoperative day except for study protocol requirements for computed tomographic scanning at 48 hours. CONCLUSION: This is the first reported series that describes the use of local anesthesia for the endovascular repair of infrarenal AAAs. Our preliminary results indicate that the endovascular treatment of AAAs with local anesthesia is feasible and can be performed safely in a patient population with significant comorbidities. The significant potential advantages include decreased cardiopulmonary morbidity rates, shorter hospital stays, and lower hospital costs. A definitive evaluation of the benefits of local anesthesia will necessitate a direct comparison with other anesthetic techniques. (+info)
Indomethacin inhibits expansion of experimental aortic aneurysms via inhibition of the cox2 isoform of cyclooxygenase.
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PURPOSE: Cyclooxygenase, either the cox1 or cox2 isoform, controls synthesis of prostaglandin E2 (PGE2), which regulates expression of matrix metalloprotease-9 (MMP-9). PGE2 and MMP-9 are elevated in aortic aneurysms. The mechanisms and time course of the inhibition of aneurysm expansion with a nonspecific cyclooxygenase inhibitor, indomethacin, were determined in an animal model. METHODS: Rats underwent aortic perfusion with saline (n = 40) as controls or with elastase. Elastase-treated animals received no treatment (n = 82) or received indomethacin (n = 73). Aortic diameters were determined at the time of aortic perfusion and when the rats were killed. The aortas were harvested and used for whole organ culture, substrate gel zymography, or histologic analysis. RESULTS: The control group demonstrated little change in aortic diameter. All the elastase-only animals developed aneurysms (maximal aortic diameter, 5.27 +/- 2.37 mm on day 14). Indomethacin markedly decreased the rate of aortic expansion (maximum aortic diameter, 3.45 +/- 1.11 mm; P <.001 vs the elastase-only group). The enzyme-linked immunosorbent assay of aortic explant culture media showed that PGE2 synthesis paralleled aortic expansion, and indomethacin decreased PGE2 synthesis. Histologically, the aortic elastin architecture was destroyed in the elastase group, but was preserved with indomethacin treatment. In situ, hybridization for cox1 and cox2 showed that cox2, but not cox1, was expressed and was co-localized by immunohistochemistry to macrophages associated with the aortic wall. Decreased levels of MMP-9 activity with indomethacin were shown by means of substrate zymography. MMP-9 was also localized to macrophages. CONCLUSION: Indomethacin attenuates aneurysm growth, and its effects are mediated via inhibition of the cox2 isoform of cyclooxygenase, which decreases PGE2 and MMP-9 synthesis. (+info)