Changes in coagulation condition, cytokine, adhesion molecule after repair of type A aortic dissection.

OBJECTIVE: Because residual dissection often exists even after the repair of a type A dissection, we evaluated coagulation conditions, cytokine levels, and adhesion molecule levels in mid-term follow up after repair of type A dissections. METHODS: Thrombin-antithrombin III complex (TAT), D-dimer, soluble interleukin-2 receptor (sIL-2R), soluble intercellular adhesion molecule (sICAM)-1, and type III procollagen peptide (PIIIP) were measured in 12 patients (mean age=63 years) following the repair of a type A aortic dissection at 6-82 months after repair (median=33 months). RESULTS: In the chronic phase, TAT and D-dimer were significantly higher in patients following the repair of a type A dissection compared to healthy controls (TAT; 12+/-8 vs. 2.5+/-1.2 ng/ml, P = 0.0001, D-dimer; 779+/-1384 vs. 104+/-46 U/ml, P = 0.0001). Cytokine was significantly higher in the affected patients (sIL-2R; 556+/-205 vs. 398+/-132 U/ml, P = 0.003, sICAM-1; 255+/-131 vs. 211+/-48 ng/ml, P = 0.136). Collagen turnover (PIIIP) showed a significantly higher value in the affected patients (0.80+/-0.32, vs. 0.58+/-0.13 U/ml, P = 0.002). sIL-2R, sICAM-1 and PIIIP showed a negative correlation with the follow-up period (sIL-2R; r = -0.733, P = 0.0067, sICAM-1; r = -0.61, P = 0.035, PIIIP; r = -0.692, P = 0.0126). We found a positive correlation between aortic size and TAT (r = 0.644, P = 0.0238, n = 12) as well as with D-dimer (r = -0.7831, P = 0.0106, n = 12) and TAT showed significantly higher values in the residual dissection group compared to those without residual dissection (16.6+/-7.9 vs. 7.45+/-4.75 ng/ml, P = 0.035). CONCLUSION: Hypercoagulation conditions continued even after repair. Both TAT and D-dimer would be good indices for following up patients having repaired aortic dissections. Furthermore, cytokine, adhesion molecules, and collagen turnover would return to a stable state unless impairment and expansion of the vessel wall occurred.     

An analysis of risk factors of perioperative bleeding in surgical repair of abdominal aortic aneurysm

BACKGROUND: In surgical repair of abdominal aortic aneurysm (AAA), excessive bleeding which causes postoperative complications is sometimes observed. To determine the risk factors of perioperative excessive blood loss, this retrospective study was performed. METHODS: Design. A retrospective study. Setting. An academic medical center. Participants. One hundred and forty patients underwent elective surgical repair of an abdominal aortic aneurysm (AAA) at our institution from 1995 through 1997. Measurements. The present study includes critical review of 140 consecutive charts of patients undergoing elective surgical repair of AAA. Preoperative laboratory data, intraoperative data and amount of blood loss to identify risk factors of perioperative blood loss. Factors which were found to be significantly associated with the amount of perioperative blood loss were preoperative plasma fibrin degradation product (FDP) level (r=0.445), amount of immediate re-infusion of shed blood (r=0.438), and duration of operation (r=0.411). RESULTS: Preoperative fibrinogen level correlated with perioperative blood loss little (r=-0.187). Preoperative platelet count or the other coagulation profile did not affect the amount of perioperative blood loss. The patients whose preoperative FDP were more than 40 microg x ml(-1) significantly increased the risk of excessive blood loss compared with less than 40 microg x ml(-1). CONCLUSIONS: The significant preoperative risk factor of perioperative blood loss was only FDP level in present study. Especially, the patients whose preoperative FDP were more than 40 microg x ml(-1) increased the risk of excessive blood loss.     

Analysis of medical risk factors and outcomes in patients undergoing open versus endovascular abdominal aortic aneurysm repair

OBJECTIVE: The emergence of endovascular repair (ER) for infrarenal abdominal aortic aneurysm (AAA) has provided surgeons with a new technique that should ideally improve patient outcomes. To more accurately characterize the advantages of ER versus traditional/open AAA repair (TOR), we compared the preoperative medical risk factors (PMRFs) and perioperative outcomes (PO) of those patients undergoing elective treatment of infrarenal AAA with ER and TOR over a recent 18-month period at our center. METHODS: Through our institutional vascular surgery patient registry, all patients undergoing aortic aneurysm repair of any type between December 1999 and June 2001 were identified. Only those patients undergoing elective infrarenal AAA repair were analyzed. Hospital records were examined for all patients, and PMRF and PO were assessed via Society for Vascular Surgery/International Society for Cardiovascular Surgery reporting guidelines. Student t, chi(2), Fisher exact, or Wilcoxon rank sum tests were applied where appropriate to determine differences among PMRF and PO according to method of aneurysm repair. RESULTS: During the 18-month study period, a total of 199 aortic aneurysms were repaired at our institution. Ninety-nine elective infrarenal AAA repairs made up the study cohort (ER, n = 33; TOR, n = 66). When examined by method of aneurysm repair, no differences existed in demographics or AAA size. Patients undergoing ER had a significantly greater degree of preoperative pulmonary comorbidity than patients undergoing TOR (P <.001). However, no differences existed in terms of American Society of Anesthesiologists classification or cardiac (P =.52), cerebrovascular (P =.44), diabetic (P =.51), hypertensive (P =.90), hyperlipidemia (P =.91) or renal (P =.23) comorbidities between the two groups. Perioperative morbidity and mortality rates were also not significantly different by method of repair. ER was associated with shorter operative time, intensive care unit stay, and overall hospital length of stay (P <.0001). However, subsequent operative procedures related to the AAA repair were performed more frequently after ER (TOR = 1.5% versus ER = 15.2%; P = 0.015). CONCLUSION: These results suggest that ER offers improvements in hospital convalescent and operating room times but no beneficial impact on overall morbidity and mortality rates when similar PMRFs exist, especially when used at medical centers where low morbidity and mortality rates are already established for TOR. Other centers performing ER should undertake such an analysis to assess its impact on their patients.     

Interplay between coagulation and inflammation in open and endovascular abdominal aortic aneurysm repair--impact of intra-aneurysmal thrombus.

AIMS: Our aim was to compare hemostatic and inflammatory mechanisms in abdominal aortic aneurysm (AAA) patients after open surgery (OPEN) and endovascular AAA repair (ENDO). SUBJECTS AND METHODS: From the 32 consecutive AAA patients recruited, 17 represented ENDO and 15 OPEN. The intra-aneurysmal thrombus was removed during OPEN, but stayed intact after ENDO. The preoperative volume of the intra-aneurysmal thrombus was calculated from computed tomography images. Markers of coagulation and inflammation were studied preoperatively, at one, two, three, four and seven days and at three months postoperatively. RESULTS: Preoperative upregulation of F 1+2, TAT and D-dimer was evident in both groups. The volume of intra-aneurysmal thrombus correlated with CRP (beta = 0.62, p = 0.001), IL-6 (beta = 0.60, p = 0.001) and PAI-1 ag (beta = 0.51, p = 0.007). Surgery further enhanced inflammation, coagulation and fibrinolysis. IL-6 increased in both groups, but the increases of CRP and PIIINP were higher in the OPEN group. Postoperative CRP correlated with the intra-aneurysmal thrombus volume in the ENDO group. At three months D-dimer (p < 0.05) was higher than preoperatively in the ENDO, in contrast to the OPEN group. CONCLUSION: Preoperatively both prothrombotic and fibrinolytic mechanisms are activated in patients with AAA. Intraluminal thrombus induces prothrombotic and inflammatory interactions, which persist after endovascular aortic aneurysm repair.     

Activated coagulation during open and endovascular abdominal aortic aneurysm repair

OBJECTIVE: The study was conducted to determine activation of coagulation in patients undergoing open and endovascular infrarenal abdominal aortic aneurysm repair (EVAR). METHODS: In a prospective, comparative study, 30 consecutive patients undergoing open repair (n = 15) or EVAR (n = 15) were investigated. Blood samples to determine fibrinopeptide A, fibrin monomer, thrombin-antithrombin complex, and D-dimer were taken up to 5 days postoperatively. Routine hematologic and hematochemical parameters as well as clinical data were collected. RESULTS: Both groups showed comparable demographic variables. Operating time was longer in open repair (249 +/- 77 minutes vs 186 +/- 69 minutes, P < .05). Perioperatively elevated markers of coagulation were measured in both groups. Fibrinopeptide A levels did not differ significantly between the groups (P = .55). The levels of fibrin monomer and thrombin-antithrombin complex were significantly higher in patients undergoing EVAR (P < .0001), reflecting increased thrombin activity and thrombin formation compared with open surgery. The D-dimer level did not differ significantly between the groups. These results were also valid after correction for hemodilution. CONCLUSION: These data suggest increased procoagulant activity in EVAR compared with open surgery. A procoagulant state may favor possible morbidity derived from micro- and macrovascular thrombosis, such as in myocardial infarction, multiple organ dysfunction, venous thrombosis and thromboembolism, or disseminated intravascular coagulation.     

Hormonal stress response and hemodynamic stability in patients undergoing endovascular vs. conventional abdominal aortic aneurysm repair.

BACKGROUND AND AIMS: To investigate the effect of two different surgical techniques with different anesthetic modes on intraoperative and postoperative hormonal stress response, hemodynamic stability, fluid loading and renal function in patients scheduled for elective infrarenal abdominal aortic aneurysm (AAA) repair. MATERIALS AND METHODS: Forty consecutive patients scheduled for elective infrarenal AAA repair were allocated without randomizing into two groups: an endovascular (EVAR, n = 20) and a conventional (CAR, n = 20) aneurysm repair group according to aneurysm morphology as determined by preoperative computed tomography and angiography. The EVAR group were operated under spinal anesthesia and the CAR group using general anesthesia with epidural blockade. RESULTS: Patients undergoing CAR showed lower intraoperative mean arterial pressure and significantly higher plasma norepinephrine before aortic cross-clamping and significantly higher lactate after aortic declamping and postoperatively than patients in the EVAR group. Postoperatively, vasopressin and serum cortisol were also significantly higher in the CAR group. Fluid loading and estimated blood loss were more excessive in the CAR group. CONCLUSIONS: Stress response was lower and hemodynamic stability and lower body perfusion superior and renal function also better maintained in patients undergoing EVAR under spinal anesthesia as compared to those undergoing CAR using general anesthesia with epidural blockade.     

Consumption of mannan-binding lectin during abdominal aortic aneurysm repair.

OBJECTIVE: Patients undergoing abdominal aortic aneurysm (AAA) repair are exposed to an ischaemia-reperfusion injury (IRI), which is in part mediated by complement activation. We investigated the role of the novel lectin pathway of complement during IRI in patients undergoing AAA repair. METHODS: Patients undergoing elective open infrarenal AAA repair had systemic blood samples taken at induction of anaesthesia, prior to aortic clamping, prior to aortic declamping and at reperfusion. Control patients undergoing major abdominal surgery were also included. Plasma was assayed for levels of mannan-binding lectin (MBL) using ELISA techniques. Consumption of plasma MBL was used as a measure of lectin pathway activation. RESULTS: Twenty-three patients undergoing AAA repair and eight control patients were recruited. No lectin pathway activation could be demonstrated in the control patients. AAA patients experienced a mean decrease in plasma MBL levels of 41% representing significant lectin pathway activation (p = 0.003). CONCLUSION: Consumption of MBL occurs during AAA repair, suggesting an important role for the lectin pathway in IRI. Specific transient inhibition of lectin pathway activity could be of significant therapeutic value in patients undergoing open surgical AAA repair.     

A personal experience with factors influencing survival after elective open repair of infrarenal aortic aneurysms

OBJECTIVE: To investigate risk factors that influence survival after open abdominal aortic aneurysm (AAA) repair in all elective patients treated by a single surgeon at a tertiary referral center. METHODS: The series includes 855 asymptomatic infrarenal AAAs in 732 men (86%) and 123 women with median ages of 69 and 71 years, respectively. Noninvasive myocardial imaging (n = 325), coronary arteriography (n = 418), or both were performed before surgery in 687 patients (80%), and 100 patients (15%) underwent preliminary coronary artery bypass grafting (n = 78) or percutaneous transluminal coronary angioplasty (n = 22) before their AAA procedures. Survival was assessed by using logistic regression analysis, proportional hazards models, and Kaplan-Meier estimations. RESULTS: The operative mortality rate was 2.5%, ranging only from 1.8% to 2.8% since 1980. Late survival rates (70% at 5 years, 36% at 10 years, and 16% at 15 years) also remained remarkably similar during five arbitrary intervals comprising the entire study period. On multivariable analysis, overall mortality rates were adversely affected by older age (P < .001), increased creatinine levels (P < .001), straight aortic replacement grafting (P < .001), larger aneurysm diameter (P = .036), and chronic obstructive pulmonary disease (P = .012). The risk for any early or late death was favorably influenced by preliminary coronary artery bypass grafting or percutaneous transluminal coronary angioplasty (hazard ratio, 0.76; 95% confidence interval, 0.59-0.98; P = .035) even when a separate multivariable model was fit to accommodate nine other patients who also had preliminary coronary intervention but developed symptomatic AAAs before elective repair could be performed (hazard ratio, 0.78; 95% confidence interval, 0.61-0.99; P = .044). CONCLUSIONS: Patient age and medical risk factors determine survival after open AAA repair to a very similar degree irrespective of the era when the operation is performed. In this particular series, preliminary coronary intervention seemed to benefit patients with severe coronary artery disease.     

Relationship between coagulation cascade, cytokine, adhesion molecule and aortic aneurysm

Objectives: Patients with aortic aneurysm (AA) were in the chronic inflammatory condition and are often combined with disseminated intervascular coagulation. Recent studies demonstrated that atherosclerosis was inflammatory disease. AA and severe atherosclerosis with ulcer formation contain macrophages and T lymphocytes and accelerate the production of interleukin (IL)-2, which activates lymphocytes and lead to further adhesion of leukocytes. This study was designed to clarify the coagulation condition, cytokine, adhesion molecule, and collagen turnover in patients with AA and finally their relationship with the aneurysmal size. Methods: Thrombin–antithrombin III complex (TAT), plasma D-dimer, serum type III procollagen peptide (PIIIP), serum soluble IL-2 receptor (sIL-2R), Free tissue factor pathway inhibitor (TFPI), and soluble intercellular adhesion molecule (ICAM-1) were measured preoperatively around the same period when computed tomography (CT) was taken in 17 patients with AA (mean age: 72.2 years). Age-matched (mean age:70 years) volunteers were served as control. Maximum aneurysmal size was measured by CT and aneurysmal volume was also calculated from CT. Results: AA patients showed significantly higher level in preoperative TAT and D-dimer compared to control (TAT: control 2.5±1.2 ng/ml, pre 7.2±4.5, ng/ml; P=0.0001; D-dimer: control 107±46 U/ml, pre 420±256 U/ml; P=0.0001). Cytokine also showed higher level preoperatively (sIL-2R: control 398±132 U/ml, pre 735±260 U/ml; P=0.0001). TFPI showed higher value preoperatively (control 22.9±4.9 ng/ml, pre 30.4±6.9 ng/ml; P=0.003). PIIIP (collagen turnover) showed no difference between the groups (P=0.0057) and neither did ICAM-1(P=0.0087). TAT (r=0.799, P=0.0001), D-dimer (r=0.56, P=0.0193), sIL-2R (r=0.709, P=0.0021), PIIIP (r=0.561, P=0.00239), and sICAM-1 (r=0.505, P=0.046) level showed positive correlation with aortic aneurysmal size and also TAT D-dimer, and sIL-2R levels were positively correlated with aneurysmal volume (r=0.714 P=0.0013, r=0.556 P=0.00204, r=0.693 P=0.0029, respectively). Conclusions: AA patients were in the hypercoagulation and inflammatory condition. Aneurysmal size was well correlated with TAT, D-dimer, sIL-2R, PIIIP, and sICAM-1, suggesting that these markers could be good diagnostic and monitoring tool for the disease progression.     

Increased nitrotyrosine production in patients undergoing abdominal aortic aneurysm repair

BACKGROUND: Vascular inflammation is implicated in the pathogenesis of atherosclerosis and abdominal aortic aneurysm (AAA), and is thought to involve reactive species such as the nitric oxide-derived oxidant peroxynitrite. In the present study nitrotyrosine was measured as a stable marker of peroxynitrite production in vivo. METHODS: Perioperative blood samples were obtained from patients undergoing elective open or endovascular repair of an AAA and from patients with intermittent claudication, smoking aged-matched controls, non-smoking aged-matched controls and non-smoking young healthy controls. Plasma nitrotyrosine was measured by an enzyme-linked immunosorbent assay. RESULTS: The median plasma nitrotyrosine concentration in patients with an AAA (0.46 nmol nitrated bovine serum albumin equivalents per mg protein) was significantly higher than that in patients with intermittent claudication (0.35 nmol; P = 0.002), smoking controls (0.36 nmol; P = 0.001), non-smoking controls (0.35 nmol; P = 0.002) and young healthy controls (0.27 nmol; P < 0.001). Nitrotyrosine concentrations increased during early reperfusion in open AAA repair, but not during endovascular repair. AAA exclusion from the circulation reduced levels to control values (P = 0.001). CONCLUSION: Patients with an AAA had raised levels of circulating nitrated proteins compared with patients with claudication and controls, suggesting a greater degree of ongoing inflammation that was not related to smoking.     

Epidemiological study of the relationship between volume and outcome after abdominal aortic aneurysm surgery in the UK from 2000 to 2005

BACKGROUND: The aim was to assess the relationship between hospital volume and outcome after abdominal aortic aneurysm (AAA) surgery in the UK. METHODS: Hospital Episode Statistics (2000-2005) were classified as elective, urgent or ruptured AAA repair. Analysis was by modelling of mortality rate, complication rate and length of hospital stay with regard to the annual operative volume, after risk adjustment. RESULTS: There were 112,545 diagnoses, or repairs, of AAAs, of which 26,822 were infrarenal aneurysms. The mean mortality rate was 7.4, 23.6 and 41.8 per cent for elective, urgent and ruptured AAA repair respectively. Elective AAA repair undertaken at high-volume hospitals showed volume-related improvements in mortality (P < 0.001). Patients were discharged from hospital earlier (P < 0.001). The critical volume threshold was 32 elective AAA repairs per year. For urgent repair, patients at high-volume hospitals had a reduced mortality rate (P = 0.017) with an increased length of stay (P = 0.041). There was no relationship between volume and outcome for ruptured AAA repairs. CONCLUSION: Increased annual volumes were associated with significant reductions in mortality for elective and urgent AAA repair, but not for repair of ruptured AAAs.     

Open aneurysm repair at an endovascular center: value of a modified retroperitoneal approach in patients at high risk with difficult aneurysms

OBJECTIVE: This study was undertaken to evaluate elective open abdominal aortic aneurysm (AAA) repair and the role of a modified retroperitoneal approach in a high-volume endovascular center. METHODS: We reviewed prospectively collected data for 175 elective infrarenal open AAA repairs performed over 6 years. A transperitoneal approach was used in 118 procedures, and a modified retroperitoneal approach was used in 57 procedures. The incisional modification, which facilitated repair in patients with massive obesity, scarring, or ventral hernia, included a higher, more posterolateral location in the ninth intercostal space. Risk factors that added to the difficulty of the repair included aneurysms with a short (<1 cm) or no aortic neck in 45 patients; large, angled or flared aortic neck in 32 patients;, tortuous and calcified iliac arteries in 6 patients; morbid obesity in 10 patients; low ejection fraction (15%-30%) in 14 patients; chronic obstructive pulmonary disease, with forced expiratory volume at 1 second less than 55% in 4 patients; previous laparotomy in 18 patients; previous left-sided colectomy in 11 patients; large right iliac aneurysm in 8 patients; large ventral hernia in 8 patients; pelvic irradiation in 4 patients; failed endovascular repair in 5 patients; and previous failed open repair attempt in 2 patients. Many of these factors occurred with significantly greater frequency (P =.04-.001) in the retroperitoneal group. All factors were correlated with outcome. RESULTS: Despite these risk factors, overall 30-day mortality was 3.5% (retroperitoneal group, 3.8%), and mean length of hospital stay was 9 days (retroperitoneal group, 8 days). There was no significant correlation between mortality or length of stay and any of the mentioned risk factors (P >.2). CONCLUSION: In the era of endovascular aneurysm exclusion, open AAA repair is generally used to treat anatomically complex or difficult aneurysms, many of which are present in patients at high risk. Despite this combination of anatomic and systemic risk factors, the modified retroperitoneal approach facilitates treatment in difficult circumstances and enables open AAA repair to be performed with acceptable mortality and morbidity.     

Activated coagulation in patients with shock due to ruptured abdominal aortic aneurysm.

BACKGROUND: Ruptured abdominal aortic aneurysm is associated with a high operative mortality. Postoperative thrombosis related complications are common, a possible mechanism being activation of the coagulation system and endothelial stimulation. The aim of the present study was to investigate the coagulation activity preoperatively in patients with ruptured and nonruptured abdominal aortic aneurysm in relation to the clinical outcome with special regard to the influence of shock. METHODS: Ninety-five patients with repair of infrarenal aortic aneurysm and forty-one controls without aneurysm matched by age, gender and smoking habits were studied. Thrombin-antithrombin (TAT), prothrombin fragment 1+2 (F 1+2), and von Willebrand factor antigen (vWFAg) were measured. RESULTS: There were significantly higher levels of TAT, F 1+2, and vWFAg in patients operated for ruptured compared to nonruptured abdominal aortic aneurysm. The highest level of TAT and F 1+2 were detected in patients with rupture and shock. CONCLUSION: The present data indicate a state of activated coagulation in patients with ruptured abdominal aortic aneurysm which is reinforced by shock.     

Disseminated Intravascular Coagulation as a Complication of Abdominal Aortic Aneurysm Repair

A retrospective review was done of all patients undergoing surgical repair of abdominal aortic aneurysm (AAA) on whom coagulation studies were obtained. Those patients with laboratory documented disseminated intravascular coagulation (DIC) were selected and their clinical records reviewed. This included 7 patients studied in the periods 1964-1965 and January 1971-July 1973. Of these 7 cases, 4 occurred in patients undergoing emergency operation for ruptured aneurysm and 3 were in elective cases. All 7 patients exhibited clinical evidence of abnormal bleeding, while 6 of the 7 progressed rapidly to renal shutdown. The seventh patient recovered spontaneously. Of the 6 patients with full blown clinical and laboratory evidence of DIC, 2 recovered. Both cases received heparin therapy and multiple hemodialyses. A third patient was started on heparin but died at 36 hours in heart failure. All 3 patients receiving heparin showed clinical cessation of abnormal bleeding and disappearance of soluble fibrin monomer complexes within 24 hours of starting therapy. The study suggests a higher incidence of DIC than has previously been appreciated in both the emergency and elective repair of AAA. The prompt recognition and treatment of this complication may reverse the abnormal intravascular clotting, minimize its more serious results and avoid futile and dangerous operative intervention.     

Myocardial injury in major aortic surgery

PURPOSE: The purpose of this study was to examine the effects of major aortic surgery and its associated oxidative stress and injury on the myocardium. METHODS: Plasma from 27 patients who underwent thoracoabdominal aortic aneurysm (TAAA) repair and 17 patients who underwent infrarenal aortic aneurysm (AAA) repair was collected at incision, aortic crossclamping, and reperfusion and 1, 8, and 24 hours thereafter. Samples were assayed for the myocardial specific protein troponin-T, total antioxidant status, and lipid hydroperoxides. RESULTS: Ten patients experienced cardiac dysfunction in the first 24 hours after surgery (eight patients in the TAAA group and two patients in the AAA group). Immediately after reperfusion, total antioxidant status levels dropped in all patients with TAAA and with AAA; this was more marked in patients with TAAA, leading to a significant difference between the two groups at this time point and for up to 1 hour thereafter (P <.01). Patients with TAAA showed a sharp rise in lipid hydroperoxide levels immediately after reperfusion, and levels were significantly higher than in patients with AAA (P =.0007). In patients with AAA, no significant change in troponin-T was observed throughout the study period; whereas in patients with TAAA, levels were significantly elevated at 8 and 24 hours after reperfusion (P <.01). Troponin-T levels significantly correlated with total antioxidant status (r = -0.5) and lipid hydroperoxides (r = 0.78) but not with systolic blood pressure. CONCLUSION: Supracoeliac aortic crossclamping is associated with a significant release of the myocardial injury marker troponin-T. This seems to correlate with the severity of oxidative rather than hemodynamic stresses. Ameliorating oxidative injury during TAAA surgery may therefore have a cardioprotective effect.     

Interleukin 6 production during abdominal aortic aneurysm repair arises from the gastrointestinal tract and not the legs

BACKGROUND: Abdominal aortic aneurysm (AAA) repair is associated with a systemic inflammatory response. This inflammatory response probably arises as a result of an ischaemia-reperfusion injury to the legs and gastrointestinal tract. In this study the relative contributions of these areas to the inflammatory response were assessed during elective AAA repair. METHODS: Blood was sampled from the femoral vein, portal vein and radial artery of 14 patients undergoing elective AAA repair at five time points during the procedure. Plasma was snap-frozen for subsequent batch analysis of interleukin (IL) 6. RESULTS: The plasma IL-6 concentration rose steadily throughout the procedure at all three locations. The increase in plasma IL-6 was significantly greater in the portal vein than in the radial artery during ischaemia (P = 0.020). The plasma IL-6 concentration was also significantly higher in the portal vein than in the femoral vein (P < 0.001) and radial artery (P < 0.001) during reperfusion. There were no significant differences between radial artery and femoral vein IL-6 levels at any time point. CONCLUSION: Ischaemia and reperfusion during AAA repair were associated with a marked increase in IL-6 concentration in the portal vein, suggesting that IL-6 was produced by the gastrointestinal tract.     

A decade of change in abdominal aortic aneurysm repair in the United States: Have we improved outcomes equally between men and women?

OBJECTIVES: Abdominal aortic aneurysm (AAA) repair has undergone vast changes in the last decade. We reviewed a national database to evaluate the effect on utilization of services and rupture rates. METHODS: From the Centers for Medicare Services (CMS), a 5% inpatient sample was obtained for 1994 to 2003 as beneficiary encrypted files (5% BEF) and as a limited data set file after 2001. Files were translated into Microsoft Access by using a custom program. Queries were performed using International Classification of Diseases (9th Revision) (ICD-9) diagnosis codes 441.3 (ruptured AAA) or 441.4 (non-ruptured AAA) and ICD-9 procedure codes 38.34, 38.36, 38.44, 38.64, 39.25, 39.52 for open, and 39.71 (available after October 2000) for endovascular repair. The 5% BEF totals were multiplied by 20 to calculate yearly volumes. Total cases were divided into the yearly CMS population of elderly Medicare recipients for repair rates per capita and are reported as cases per 100,000 elderly Medicare recipients. Statistics were performed using chi2, Student's t test, nonparametric tests, and multiple regression analysis; P < or = .05 was considered significant. RESULTS: Elective AAA repairs declined from 94.4/100,000 in 1994 to 87.7/100,000 in 2003. AAA rupture surgery declined from 18.7/100,000 (1994) to 13.6/100,000 (2003). Rupture repairs from 1994 to 2003 decreased by 29% for men and by 12% for women (P < .001). Rupture mortality has not changed, but the average is significantly higher for women at 52.8%, with men averaging 44.2% (P < .001). Mortality for elective AAA repair has decreased from 5.57% (1994) to 3.20% (2003) in men (P < .001) and from 7.48% (1994) to 5.45% (2003) in women (P < .001). Multivariate analysis demonstrated increasing age, female sex, and open surgery (vs endovascular) were significant predictors of elective and ruptured AAA repair mortality. For 2003 elective AAA repairs, the average length of stay was 6.9 days in men and 8.9 days in women (P < .01) For 2003, men were more likely to be discharged to home after rupture (32.9% of men vs 23.3% of women; P < .001) and elective repair (84.5% of men vs 70.1% of women; P < .001). CONCLUSIONS: Improvements in AAA management in the last decade have decreased aneurysm-related deaths and reduced the incidence of aneurysm ruptures, with a lower utilization of services. Women, however, continue to have a consistently higher mortality for open and ruptured AAA repair and are less likely to return to home after either.     

Ischaemia and reperfusion during open abdominal aortic aneurysm surgery induce extensive thrombin generation and activity.

OBJECTIVES: does open surgery for abdominal aortic aneurysm (AAA) influence coagulation? METHODS: in 23 patients operated on for AAA, cubital blood was sampled pre-, intra- and postoperatively. Femoral blood was also sampled intraoperatively. RESULTS: preoperatively, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and soluble fibrin (SF) were elevated in AAA patients. During aortic clamping all parameters increased significantly in cubital blood (p<0.01) as well as in femoral blood (p<0.001) and after aortic declamping F1+2 and TAT increased further. F1+2, TAT and SF were significantly higher in femoral than cubital blood. Postoperatively F1+2 and TAT returned to preoperative values, while SF still had a significantly higher level than preoperatively (p<0.001). Blood loss showed co-variation with F1+2 increase in femoral blood after aortic declamping (p<0.05). CONCLUSIONS: these data indicate that the coagulation system was strongly activated by the occurrence of an AAA. During AAA surgery a further extensive activation was seen. The activity was still high, but on decline, one week postoperatively. Ischaemia and reperfusion of the lower part of the body were the major stimuli for thrombin generation and activity.     

Cytokines, their genetic polymorphisms, and outcome after abdominal aortic aneurysm repair.

BACKGROUND: Excessive cytokine production has been implicated in the development of organ failure. Polymorphic sites in cytokine genes have been shown to affect levels of production in vitro and may influence cytokine production in vivo. The aims of this study were to determine if cytokines or their genetic polymorphisms were related to outcome after abdominal aortic aneurysm (AAA) repair. METHODS: A prospective study of 135 patients undergoing open AAA repair. Plasma levels of TNF-alpha, IL-1beta, IL-6 and IL-10 were measured 24 h post-operatively and genotypes for the TNF-alpha -308, IL-1beta+3953, IL-6 -174, IL-10 -1082 and IL-10 -592 polymorphisms were determined for each patient. RESULTS: After elective AAA high levels of IL-10 were associated with both prolonged critical care (P<0.001) and hospital stay (P=0.001). The presence of a G allele at the IL-6 -174 locus was associated with a higher incidence of organ failure (P=0.04) and an A allele at TNF-alpha -308 with prolonged critical care stay (P=0.03). After ruptured AAA the development of multi-organ failure was associated with high levels of IL-6 (P=0.01) and TNF-alpha (P=0.04). High TNF-alpha levels were also associated with mortality (P=0.01). CONCLUSION: Post-operative cytokine levels are related to outcome after AAA repair. Cytokine gene polymorphisms may provide a method for determining which patients are at high risk of complications.     

Activated protein C-protein C inhibitor complex in patients with abdominal aortic aneurysms: is it associated with diameter and growth rate?

Increased thrombin activation was documented in patients with abdominal aortic aneurysm (AAA). Activated protein C-protein C inhibitor (APC-PCI) complex, a new biological marker of thrombin generation, was measured in a population of 232 patients with AAA and a control group, and the association between aneurysm size, growth rate, and APC-PCI was studied. The patients were divided into cohorts according to AAA diameter and compared with a control group. APC-PCI was significantly higher in all AAA cohorts (n = 232; median, 0.36 microg/L; 10th to 90th percentile, 0.18-1.01) compared with the control group (n = 41; median, 0.19 microg/L; 10th to 90th percentile, 0.11-0.31; P < or = .001). APC-PCI correlated with AAA diameter (r = .22; P = .001), body mass index (r = -.19; P = .004), and age (r = .19; P = .004). APC-PCI did not correlate with AAA growth rate (r = .11; P = .14).