Randomized controlled trial of dual antiplatelet therapy in patients undergoing surgery for critical limb ischemia.

BACKGROUND AND OBJECTIVE: Patients with critical limb ischemia have a perioperative cardiovascular morbidity comparable to patients with acute coronary syndromes. We hypothesized that perioperative dual antiplatelet therapy would improve biomarkers of atherothrombosis without causing unacceptable bleeding in patients undergoing surgery for critical limb ischemia. METHODS: In a double-blind randomized controlled trial, 108 patients undergoing infrainguinal revascularization or amputation for critical limb ischemia were maintained on aspirin (75 mg daily) and randomized to clopidogrel (600 mg prior to surgery, and 75 mg daily for 3 days; n = 50) or matched placebo (n = 58). Platelet activation and myocardial injury were assessed by flow cytometry and plasma troponin concentrations, respectively. RESULTS: Clopidogrel reduced platelet-monocyte aggregation before surgery (38%-30%; P = 0.007). This was sustained in the postoperative period (P = 0.0019). There were 18 troponin-positive events (8 [16.0%] clopidogrel vs. 10 [17.2%] placebo; relative risk [RR]: 0.93, 95% confidence interval [CI]: 0.39-2.17; P = 0.86). Half of troponin-positive events occurred preoperatively with clopidogrel causing a greater decline in troponin concentrations (P < 0.001). There was no increase in major life-threatening bleeding (7 [14%] vs. 6 [10%]; RR: 1.4, 95% CI: 0.49-3.76; P = 0.56) or minor bleeding (17 [34%] vs. 12 [21%]; RR 1.64, 95% CI: 0.87-3.1; P = 0.12), although blood transfusions were increased (28% vs. 12.6%, RR: 2.3, 95% CI: 1.0-5.29; P = 0.037). CONCLUSIONS: In patients with critical limb ischemia, perioperative dual antiplatelet therapy reduces biomarkers of atherothrombosis without causing unacceptable bleeding. Large-scale randomized controlled trials are needed to establish whether dual antiplatelet therapy improves clinical outcome in high-risk patients undergoing vascular surgery.

Prognostic scoring in ruptured abdominal aortic aneurysm: a prospective evaluation.

BACKGROUND: Prospective validation of prognostic scoring systems for ruptured abdominal aortic aneurysm (AAA) is lacking. This study assesses the validity of three established risk scores and a new prognostic index. METHOD: Patients admitted with ruptured AAA during a 26-month period (August 2002-December 2004) were recruited prospectively. The Glasgow Aneurysm Score (GAS), Hardman Index, Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) scores, and the Edinburgh Ruptured Aneurysm Score (ERAS) were recorded and related to outcome. RESULTS: During the study period, 111 patients were admitted with ruptured AAA. Of these, 84 (76%) underwent attempted operative repair and were included in the study; 37 (44%) died after operation. The GAS, Hardman Index, and the ERAS were statistically related to mortality. However, analysis by receiver-operator characteristic curve revealed the ERAS to have an area under the curve (AUC) of 0.72 (95% confidence interval [CI], 0.61-0.83). The vascular (V)-POSSUM and ruptured AAA (RAAA)-POSSUM models had an AUC of 0.70 (95% CI, 0.59-0.82). The Hardman Index and GAS had an AUC of 0.69 (95% CI, 0.57-0.80) and 0.64 (95% CI, 0.52-0.76), respectively. Although the V-POSSUM equation predicted mortality effectively (P = .086), the RAAA-POSSUM derivative demonstrated a significant lack of fit (P = .009). CONCLUSION: Prospective validation shows that the Hardman Index, GAS, and V-POSSUM and RAAA-POSSUM scores do not perform well as predictors for death after ruptured AAA. The ERAS accurately stratifies perioperative risk but requires further validation.

Prediction of outcome after abdominal aortic aneurysm rupture.

BACKGROUND: Most vascular surgeons practice a selective policy of operative intervention for patients with ruptured abdominal aortic aneurysm (AAA). The evidence on which to justify operative selection remains uncertain. This review examines the prediction of outcome after attempted open repair of ruptured AAA. METHODS: The Medline and EMBASE databases and Cochrane Database of Systematic Reviews were searched for clinical studies relating to the prediction of outcome after ruptured AAA. Reference lists of relevant articles were also reviewed. RESULTS: The last 20 years has seen >60 publications considering variables predictive of outcome after AAA rupture. Four predictive scoring systems are reported: Hardman Index, Glasgow Aneurysm Score, Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity (POSSUM), and the Vancouver Scoring System. No scoring system has been shown to have consistent or absolute validity. Of the remaining data, there are no individual or combination of variables that can accurately and consistently predict outcome. CONCLUSIONS: Little robust evidence is available on which to base preoperative outcome prediction in patients with ruptured AAA. Experienced clinical judgement will remain of foremost importance in the selection of patients for ruptured AAA repair.

Systemic inflammation and repair of abdominal aortic aneurysm.

BACKGROUND: Inflammation is integral to the pathogenesis of abdominal aortic aneurysm (AAA). This study examines preoperative biomarkers of systemic inflammation in patients undergoing open repair of intact and ruptured AAA. METHODS: One-hundred twelve patients were entered into a prospective observational study. Preoperative POSSUM physiology score, C-reactive protein (CRP), white blood count (WBC), platelet count, fibrinogen, and albumin were recorded and related to clinical variables using univariate analysis. RESULTS: Sixty-one patients with a ruptured AAA, 39 with an asymptomatic intact AAA, and 12 with an acutely symptomatic intact AAA underwent attempted repair. There were two inflammatory asymptomatic aneurysms and one inflammatory ruptured aneurysm. No patient had clinical evidence of coexistent inflammatory disease. Patients with a symptomatic intact AAA had a significantly greater level of CRP and fibrinogen, higher WBC, and lower serum albumin, than those with an asymptomatic intact AAA. Patients with a ruptured aneurysm had a significantly greater level of CRP, higher WBC, and lower serum albumin than those with an asymptomatic intact aneurysm. Patients with a symptomatic intact AAA had a significantly higher CRP level, but lower WBC, than those with a ruptured AAA. There was no difference in CRP level, WBC, or serum albumin between survivors and non-survivors of attempted repair of asymptomatic, symptomatic and ruptured AAA. CONCLUSIONS: Acutely symptomatic and ruptured AAAs are associated with an early elevation in systemic inflammatory biomarkers. This early activation of the inflammatory response might influence perioperative outcome.

Outcome and survival of patients aged 65 years and younger after abdominal aortic aneurysm rupture.

Advanced age (> 80 years) confers a survival disadvantage after operative repair of a ruptured abdominal aortic aneurysm (AAA). This study aimed to determine if young age (< or =65 years) confers a survival benefit. Consecutive patients undergoing attempted repair of a ruptured AAA between 1995 and 2001 were included in the study. Demographic, clinical, and operative factors were analyzed together with in-hospital mortality, duration of postoperative hospital stay, and long-term survival. Of 378 patients admitted with a ruptured AAA, 52 (14%) were < or = 65 years of age and 326 (86%) were > 65 years. There were 4 (8%) women in the younger cohort compared to 74 (23%) women in the older group (p = 0.015). Four (8%) patients in the younger group were thought to be unsuitable for surgical repair compared to 77 (24%) patients in the older cohort (p = 0.009). Of the 48 younger patients who underwent attempted operative repair, 22 (46%) died in hospital, compared to 108 (43%) of 249 patients > 65 years (p = 0.753). The median (range) postoperative hospital stay of survivors was 11 days (6-59 days) in the younger cohort and 15 days (6-121 days) in the older group (p = 0.005). Patients < or = 65 years of age undergoing operative repair of ruptured AAA have no survival advantage over older patients. These data support AAA screening for the "at risk" and age-defined population.

Functional outcome after open repair of ruptured abdominal aortic aneurysm.

BACKGROUND: Outcome after operative repair of ruptured abdominal aortic aneurysm (AAA) has traditionally been assessed in terms of survival. This study examines the functional outcome of patients who survive operation. METHODS: Consecutive patients who survived open repair over an 18-month period were entered into a prospective case-control study. Age- and sex-matched controls were identified from patients undergoing elective AAA repair. The Short Form-36 health survey was administered to both groups of patients at 6 months after operation. Results were compared with the expected scores for an age- and sex-matched normal UK population. RESULTS: Fifty-seven patients underwent open repair of a ruptured AAA, and 30 survived; no patient was lost to follow-up. There were no significant differences in quality of life between patients who had an emergency repair and those who had an elective repair. Both of these groups had poorer health-related quality of life outcomes than the matched normal population. Surprisingly, compared with the normal population, patients after elective repair had poorer outcomes in more health domains than patients who survived emergency operation. CONCLUSIONS: Survivors of ruptured AAA repair have a good functional outcome within 6 months of operation.

Ruptured inflammatory abdominal aortic aneurysm: insights in clinical management and outcome.

BACKGROUND: Ruptured inflammatory abdominal aortic aneurysm (AAA) is relatively rare, and little has been written on the outcome of operative treatment. METHODS: Patients undergoing attempted repair of ruptured inflammatory AAA between 1995 and 2001 were included in a retrospective case-cohort study. Demographic, clinical, and operative factors were analyzed, together with in-hospital morbidity, in-hospital mortality, and duration of postoperative hospital stay. RESULTS: Of 297 patients who underwent attempted operative repair of ruptured AAA, 24 (8%) had an inflammatory aneurysm. Twenty-two patients were men, and two were women; median age was 69 years (range, 51-85 years). Operative findings revealed a contained hematoma in 16 patients (70%), free rupture in 3 patients (13%), aortocaval fistula in 4 patients (17%), and aortoenteric fistula in 1 patient (4%). Of 273 noninflammatory ruptured AAAs, only 2 AAA (1%) were associated with primary aortic fistula. Ten patients (42%) with inflammatory AAA died in hospital, compared with 117 of 273 patients (43%) without inflammation. Median postoperative stay was 10 days (range, 0-35 days). Of the 14 patients with inflammatory lesions who survived, 11 had postoperative complications; 4 patients had acute renal failure, three of whom required temporary renal replacement therapy. CONCLUSIONS: Ruptured inflammatory AAA is associated with a higher incidence of aortic fistula than is ruptured noninflammatory AAA. Repair of ruptured inflammatory AAA is not associated with increased operative mortality compared with repair of ruptured noninflammatory AAA.