Open Infrarenal Abdominal Aortic Aneurysm Research Articles

Limb Remote Ischemic Preconditioning for Intestinal and Pulmonary Protection during Elective Open Infrarenal Abdominal Aortic Aneurysm Repair

Remote ischemic preconditioning (RIPC) may confer the cytoprotection in critical organs. The authors hypothesized that limb RIPC would reduce intestinal and pulmonary injury in patients undergoing open infrarenal abdominal aortic aneurysm repair. In this single-center, prospective, double-blinded, randomized, parallel-controlled trial, 62 patients undergoing elective open infrarenal abdominal aortic aneurysm repair were randomly assigned in a 1:1 ratio by computerized block randomization to receive limb RIPC or conventional abdominal aortic aneurysm repair (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff placed on the left upper arm served as RIPC stimulus. The primary endpoint was arterial-alveolar oxygen tension ratio. The secondary endpoints mainly included the intestinal injury markers (serum intestinal fatty acid-binding protein, endotoxin levels, and diamine oxidase activity), the markers of oxidative stress and systemic inflammatory response, and the scores of the severity of intestinal and pulmonary injury. In limb RIPC group, a/A ratio was significantly higher than that in control group at 8, 12, and 24 h after cross-clamp release (66 ± 4 vs. 45 ± 4, P = 0.003; 60 ± 6 vs. 37 ± 4, P = 0.002; and 60 ± 5 vs. 47 ± 6, P = 0.039, respectively). All biomarkers reflecting intestinal injury increased over time, and there was significant differences between limb RIPC and control group (P < 0.001). The severity of intestinal and pulmonary injury was decreased by limb RIPC (P = 0.014 and P = 0.001, respectively). Limb RIPC attenuates intestinal and pulmonary injury in patients undergoing elective open infrarenal abdominal aortic aneurysm repair without any potential risk.

Inadvertent placement of a pulmonary artery catheter in the coronary sinus: is it time to increase our sweep speed?

A patient was scheduled for open infrarenal abdominal aortic aneurysm repair and the procedure was performed without complication. The pulmonary artery catheter (PAC) was unintentionally placed in the coronary sinus via an undiagnosed persistent left superior vena cava anomaly. Interpreting the waveform produced by the PAC in standard and abnormal locations such as the coronary sinus is equally as important as measuring and monitoring hemodynamic status.

Comparison of modern open infrarenal and pararenal abdominal aortic aneurysm repair on early outcomes and renal dysfunction at one year

This study was conducted to review contemporary results of elective open infrarenal abdominal aortic aneurysm (IAAA) and pararenal abdominal aortic aneurysm (PAAA) repairs and determine predictors of death and acute and 1-year renal dysfunction (RD). A retrospective review identified 432 consecutive patients undergoing open IAAA (233 patients) or PAAA (184 patients) repair between January 2000 and December 2007. Demographic, preoperative, intraoperative, and postoperative variables were collected. RD was defined as an increase in creatinine of ≥ 0.5 mg/dL from baseline. Multiple logistic regression models were used to identify predictors of mortality and RD. Mortality rates were similar between the groups (3.9% IAAA and 6.0% PAAA). Preoperative coronary artery disease (CAD), postoperative myocardial infarction, or pulmonary complications were all strong predictors of operative mortality in patients undergoing repair of PAAAs and IAAAs. However, neither PAAA nor baseline renal insufficiency was an independent predictor of death. Postoperative RD occurred in 32% of patients after PAAA repairs compared with 13% of patients after IAAA repairs (P < .001). The presence of PAAA, baseline hypertension, and hyperlipidemia all correlated positively with postoperative RD, while a trend was noted with baseline renal insufficiency (P = .09). At the 1-year follow-up, 5.1% of patients in the PAAA group had RD compared with none in the IAAA group. Similarly, the serum creatinine level was significantly higher in the PAAA group (1.4 mg/dL vs 1.2 mg/dL, PAAA and IAAA, respectively; P = .02) at 1 year. However, there were no instances of new-onset hemodialysis dependence at 1 year. Mean follow-up was 2.2 years overall. Open PAAA repair can be performed without a significant increase in mortality compared to open IAAA repair. Although the incidence of renal function deterioration after open PAAA repairs remains higher than with open IAAA repairs, the overall incidence remains low at 1-year follow-up.

Endovascular Management of a Ruptured Thoracoabdominal Aneurysm—Damage Control With Superior Mesenteric Artery Snorkel and Thoracic Stent-Graft Exclusion

We report a case of a large ruptured thoracoabdominal aortic aneurysm, which was stabilized with endovascular aortic exclusion and snorkel bypass of the superior mesenteric artery (SMA). An 80-year-old African American woman with multiple medical comorbidities and previous open infrarenal abdominal aortic aneurysm repair presented with a ruptured 10.7 × 7.3 cm thoracoabdominal aortic aneurysm involving the origins of the renal and mesenteric vessels. The patient underwent emergent endovascular aortic repair with placement of a covered stent into the SMA coursing parallel to the aortic endograft. This technique was initially successful in clinically stabilizing the patient; however; 3 weeks after the initial procedure, she presented with recurrent rupture necessitating proximal extension of her snorkeled SMA bypass and aortic endograft into the mid-descending thoracic aorta. The patient stabilized and was successfully discharged home.

Risk Factors for Postoperative Complications after Open Infrarenal Abdominal Aortic Aneurysm Repair in Koreans

PurposeOpen infrarenal abdominal aortic aneurysm (AAA) repair is performed without event in most cases. However, some patients suffer major morbidities such as renal failure, myocardial infarction, paraplegia, acute respiratory distress syndrome, or hepatic dysfunction. Predicting what kinds of patient populations are more prone to develop such complications may keep the clinicians more attentive to the patients, possibly leading to better prognoses. In this retrospective study, we searched the incidence of and risk factors for postoperative complications and their predictive equations in 162 patients who underwent open infrarenal AAA repair.Materials and MethodsPostoperative complications were observed within 30 days. Patient characteristics, types of aneurysm and surgery, and hemodynamic and metabolic variables during the periclamp period were analyzed in relation to postoperative complications using multiple logistic regression analysis.ResultsPostoperative complications involved the cardiac (20%), pulmonary (14%), renal (13%), gastrointestinal (6%), hepatic (3.1%), and neurologic (2.5%) systems, and bleeding occurred in 1.2% of cases. The mortality rate was 5.6%. The risk factors were age [> 67 yrs, odds ratio (OR) 2.6], clamp duration (> 110 min, OR 4.7), volume of blood transfusion (> 1,280 mL, OR 4.4), emergency operation (OR 1.4), and vasopressor infusion during clamp (OR 1.4). The prediction model was: P(x) = exp(α)/[1 + exp(α)] α;-2.2 + 0.9 × age + 1.5 × clamp duration + 1.5 × transfusion + 0.3 × emergency + 0.4 × vasopressor infusion [insert 1 if risk factors exist, otherwise, insert 0 to each variable].ConclusionA significant number of complications occurred after infrarenal AAA repair. Therefore, creating a protocol to identify and monitor high risk patients would improve postoperative care.

National Outcomes after Open Repair of Abdominal Aortic Aneurysms with Visceral or Renal Bypass

Background: We evaluated national outcomes after open repair of abdominal aortic aneurysms (AAAs) with visceral or renal bypass (VRB). Methods: Using the National Inpatient Sample database from 1993 through 2006, AAA repairs were identified by ICD9 codes for diagnosis of intact AAA combined with a procedure of open AAA repair. VRB patients also had an aortorenal and/or mesenteric bypass or mesenteric endarterectomy. Dissections as well as thoracic and thoracoabdominal aneurysms were excluded. Demographics and comorbidities were noted. Mortality and complications were compared to infrarenal AAA (IRA) repairs without VRB. Predictors of perioperative mortality were analyzed by multivariate logistic regression. Results: A total of 41,166 VRB and 362,808 IRA repairs were identified. VRB repair volume decreased by 58%and IRA volumedecreased by 59% from1993 to 2006. VRBpatients had higher mortality (5.8% vs. 4.4%, p< 0.001) andmore complications including acute renal failure (9.5% vs. 6.0%,p< 0.001), acutemesenteric ischemia (2.0%vs. 1.2%), and bowel resection (1.1%vs. 0.8%, p< 0.01). Patients requiring a bowel resection or with acute renal failure were 10 times more likely to die within the hospital stay regardless of repair type. Independent preoperative predictors of mortality were VRB (odds ratio [OR]1⁄4 1.3, 95% confidence interval [CI] 1.2e1.5), age (OR1⁄4 1.4 per decade, 95% CI 1.4e1.5), chronic renal failure (OR1⁄4 5.5, 95% CI 4.9e6.3), congestive heart failure (OR1⁄4 7.5, 95% CI 6.1e9.3), and pulmonary disease (OR1⁄4 1.2, 95% CI 1.1e1.2). Conclusion: VRB repair volume decreased per year similarly to open IRA repair volume and may be related to increasing use of endovascular therapy. Mortality after VRB is high and dependent upon age, renal failure, and congestive heart failure. Overall, VRB repair was associated with worsened outcomes; however, this study cannot conclude that avoiding such a repair will improve outcomes. This should be factored into surgical decision making for these patients.

Why routine intensive care unit admission after elective open infrarenal Abdominal Aortic Aneurysm repair is no longer an evidence based practice

Background Elective open infrarenal Abdominal Aortic Aneurysm (AAA) repair is major surgery performed on high-risk patients. Routine ICU admission postoperatively is the current accepted standard of care. Few of these patients actually require a level of care that cannot be provided just as effectively in a surgical high dependency unit (HDU). Our aim was to determine, ‘can high risk patients that will require ICU admission postoperatively be reliably identified preoperatively?’. Methods A retrospective analysis of all elective open infrarenal AAA repairs in our institution over a 3-year period was performed. The Estimation of Physiological Ability and Surgical Stress (E-PASS) model was used as our risk stratification tool for predicting post-operative morbidity. Renal function was also considered as a predictor of outcome, independent of the E-PASS. Results 80% ( n = 16) were admitted to ICU. Only 30% ( n = 6) of the total study population necessitated intensive care. There were 9 complications in 7 patients in our study. The E-PASS comprehensive risk score (CRS)/Surgical stress score (SSS) were found to be significantly associated with the presence of a complication ( p = 0.009)/( p = 0.032) respectively. Serum creatinine ( p = 0.013) was similarly significantly associated with the presence of a complication. Conclusions The E-PASS model possessing increasing external validity is an effective risk stratification tool in safely deciding the appropriate level of post-operative care for elective infrarenal AAA repairs.

The Vascular Study Group of New England Cardiac Risk Index (VSG-CRI) predicts cardiac complications more accurately than the Revised Cardiac Risk Index in vascular surgery patients

The Revised Cardiac Risk Index (RCRI) is a widely used model for predicting cardiac events after noncardiac surgery. We compared the accuracy of the RCRI with a new, vascular surgery-specific model developed from patients within the Vascular Study Group of New England (VSGNE). We studied 10,081 patients who underwent nonemergent carotid endarterectomy (CEA; n = 5293), lower extremity bypass (LEB; n = 2673), endovascular abdominal aortic aneurysm repair (EVAR; n = 1005), and open infrarenal abdominal aortic aneurysm repair (OAAA; n = 1,110) within the VSGNE from 2003 to 2008. First, we analyzed the ability of the RCRI to predict in-hospital major adverse cardiac events, including myocardial infarction (MI), arrhythmia, or congestive heart failure (CHF) in the VSGNE cohort. Second, we used a derivation cohort of 8208 to develop a new cardiac risk prediction model specifically for vascular surgery patients. Chi-square analysis identified univariate predictors, and multivariate logistic regression was used to develop an aggregate and four procedure-specific risk prediction models for cardiac complications. Calibration and model discrimination were assessed using Pearson correlation coefficient and receiver operating characteristic (ROC) curves. The ability of the model to predict cardiac complications was assessed within a validation cohort of 1873. Significant predictors were converted to an integer score to create a practical cardiac risk prediction formula. The overall incidence of major cardiac events in the VSGNE cohort was 6.3% (2.5% MI, 3.9% arrhythmia, 1.8% CHF). The RCRI predicted risk after CEA reasonably well but substantially underestimated risk after LEB, EVAR, and OAAA for low- and higher-risk patients. Across all VSGNE patients, the RCRI underestimated cardiac complications by 1.7- to 7.4-fold based on actual event rates of 2.6%, 6.7%, 11.6%, and 18.4% for patients with 0, 1, 2, and >or=3 risk factors. In multivariate analysis of the VSGNE cohort, independent predictors of adverse cardiac events were (odds ratio [OR]) increasing age (1.7-2.8), smoking (1.3), insulin-dependent diabetes (1.4), coronary artery disease (1.4), CHF (1.9), abnormal cardiac stress test (1.2), long-term beta-blocker therapy (1.4), chronic obstructive pulmonary disease (1.6), and creatinine >or=1.8 mg/dL (1.7). Prior cardiac revascularization was protective (OR, 0.8). Our aggregate model was well calibrated (r = 0.99, P < .001), demonstrating moderate discriminative ability (ROC curve = 0.71), which differed only slightly from the procedure-specific models (ROC curves: CEA, 0.74; LEB, 0.72; EVAR, 0.74; OAAA, 0.68). Rates of cardiac complications for patients with 0 to 3, 4, 5, and >or=6 VSG risk factors were 3.1%, 5.0%, 6.8%, and 11.6% in the derivation cohort and 3.8%, 5.2%, 8.1%, and 10.1% in the validation cohort. The VSGNE cardiac risk model more accurately predicted the actual risk of cardiac complications across the four procedures for low- and higher-risk patients than the RCRI. When the VSG Cardiac Risk Index (VSG-CRI) was used to score patients, six categories of risk ranging from 2.6% to 14.3% (score of 0-3 to 8) were discernible. The RCRI substantially underestimates in-hospital cardiac events in patients undergoing elective or urgent vascular surgery, especially after LEB, EVAR, and OAAA. The VSG-CRI more accurately predicts in-hospital cardiac events after vascular surgery and represents an important tool for clinical decision making.

Remote Ischemic Preconditioning for Renal Protection During Elective Open Infrarenal Abdominal Aortic Aneurysm Repair: Randomized Controlled Trial

We aimed to determine whether remote ischemic preconditioning (IP) reduces renal damage following elective open infrarenal abdominal aortic aneurysm (AAA) repair. Sequential common iliac clamping was used to induce remote IP in randomized patients. Urinary retinol binding protein (RBP) and albumin-creatinine ratio (ACR) were measured following induction and 3, 24, and 48 hours postoperatively. In controls (n = 22), median urinary RBP increased from 112 microg/mL (interquartile range [IQR] 96-173 microg/mL) preoperatively to 5919 microg/mL (IQR 283-17 788 microg/mL) at 3 hours. Preoperative urinary RBP in preconditioned patients was 96 microg/mL (IQR 50 to 229 microg/mL) preoperatively, rising to 1243 microg/mL (IQR 540 to 15400 microg/mL) at 3 hours. Although control patients' median urinary RBP level was 5 times greater at 3 hours, there were no statistically significant differences in renal outcome indices. This trial could not confirm that remote IP reduces renal injury following elective open aneurysm surgery.

National Outcomes after Open Repair of Abdominal Aortic Aneurysms with Visceral or Renal Bypass

We evaluated national outcomes after open repair of abdominal aortic aneurysms (AAAs) with visceral or renal bypass (VRB). Using the National Inpatient Sample database from 1993 through 2006, AAA repairs were identified by ICD9 codes for diagnosis of intact AAA combined with a procedure of open AAA repair. VRB patients also had an aortorenal and/or mesenteric bypass or mesenteric endarterectomy. Dissections as well as thoracic and thoracoabdominal aneurysms were excluded. Demographics and comorbidities were noted. Mortality and complications were compared to infrarenal AAA (IRA) repairs without VRB. Predictors of perioperative mortality were analyzed by multivariate logistic regression. A total of 41,166 VRB and 362,808 IRA repairs were identified. VRB repair volume decreased by 58% and IRA volume decreased by 59% from 1993 to 2006. VRB patients had higher mortality (5.8% vs. 4.4%, p < 0.001) and more complications including acute renal failure (9.5% vs. 6.0%, p < 0.001), acute mesenteric ischemia (2.0% vs. 1.2%), and bowel resection (1.1% vs. 0.8%, p < 0.01). Patients requiring a bowel resection or with acute renal failure were 10 times more likely to die within the hospital stay regardless of repair type. Independent preoperative predictors of mortality were VRB (odds ratio [OR] = 1.3, 95% confidence interval [CI] 1.2-1.5), age (OR = 1.4 per decade, 95% CI 1.4-1.5), chronic renal failure (OR = 5.5, 95% CI 4.9-6.3), congestive heart failure (OR = 7.5, 95% CI 6.1-9.3), and pulmonary disease (OR = 1.2, 95% CI 1.1-1.2). VRB repair volume decreased per year similarly to open IRA repair volume and may be related to increasing use of endovascular therapy. Mortality after VRB is high and dependent upon age, renal failure, and congestive heart failure. Overall, VRB repair was associated with worsened outcomes; however, this study cannot conclude that avoiding such a repair will improve outcomes. This should be factored into surgical decision making for these patients.

Preliminary Results of a Prospective Randomized Trial of Restrictive Versus Standard Fluid Regime in Elective Open Abdominal Aortic Aneurysm Repair

Open abdominal aortic aneurysm (AAA) repair is associated with a significant morbidity (primarily respiratory and cardiac complications) and an overall mortality rate of 4% to 10%. We tested the hypothesis that perioperative fluid restriction would reduce complications and improve outcome after elective open AAA repair. In a prospective randomized control trial, patients undergoing elective open infra-renal AAA repair were randomized to a "standard" or "restricted" perioperative fluid administration group. Primary outcome measure was rate of major complications (MC) after AAA repair and secondary outcome measures included: Sequential Organ Failure Assessment Score; FiO2/PO2 ratio; Urinary Albumin/Creatinine Ratio; Length-of-stay in, intensive care unit, high dependency unit, in-hospital. This prospective Randomized Controlled Trial was registered in a publicly accessible database and has the following ID number ISRCTN27753612. Overall 22 patients were randomized, 1 was excluded on a priori criteria, leaving standard group (11) and restricted group (10) for analysis. No significant difference was noted between groups in respect to age, gender, American Society Anesthesiology class, Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity scores, operation time, and operation blood loss. There were no in-hospital deaths and no 30-day mortality. The cumulative fluid balance on day 5 postoperative was for standard group, 8242 +/- 714 mL, compared with restricted group, 2570 +/- 977 mL, P < 0.01. MC were significantly reduced in the restricted group (n = 10), 1 MC, compared with standard group (n = 11), 14 MC, P < 0.024. Total and postoperative length-of-stay in-hospital was significantly reduced in the restricted group, 9 +/- 1 and 8 +/- 1 days, compared with standard group, 18 +/- 5 and 16 +/- 5 days, P < 0.01 and P < 0.025, respectively. Serious complications are common after elective open AAA repair, and we have shown for the first time that a restricted perioperative fluid regimen can prevent MC and significantly reduce overall hospital stay.

Natural history of common iliac arteries after aorto-aortic graft insertion during elective open abdominal aortic aneurysm repair: A prospective study

This study aimed to determine the natural history of common iliac arteries (CIAs) after elective open infrarenal abdominal aortic aneurysm (AAA) repair with an aorto-aortic prosthetic graft. All patients who had a straight tube graft inserted during elective AAA repair at our institution between 1995 and 2005 were prospectively followed up with preoperative and postoperative computed tomography (CT) scans to monitor changes in CIA diameter; their latest CT scan was performed in 2007. Based on preoperative CIA diameter, patients were divided into groups A (both CIAs normal, up to 12 mm in diameter), B (at least 1 ectatic CIA, 13-18 mm), and C (at least 1 aneurysmal CIA, 19-25 mm). The mean follow-up was 7.1 years (range, 2.1-12.3 years). Among 201 patients eligible for the study, 92 patients (45.8%) were in group A, 63 patients (31.3%) were in group B, and 46 patients (22.9%) were in group C. Overall, the diameter increased in 119 CIAs (29.6%) by a mean of 1.1, 1.8, and 2.4 mm in groups A, B, and C, respectively. In all, 14 CIAs (5.4%) progressed from "normal" to "ectatic," and 9 CIAs (10.2%) progressed from "ectatic" to "aneurysmal." Three aneurysmal CIAs slightly exceeded the 25-mm threshold, but none of these were repaired. No patients showed a progression or development of occlusive iliac artery disease or required repeat operation because of excessive CIA enlargement. This analysis showed that most CIAs do not expand after tube graft insertion during AAA repair, and when they do, the degree of dilation is minimal. Tube graft insertion during AAA repair is justified even for ectatic or moderately aneurysmal CIAs, and the procedure is safe and durable. The skepticism surrounding its selective use instead of a systematic bifurcated graft placement seems to be unwarranted.

A Global Assessment of the Inflammatory Response Elicited Upon Open Abdominal Aortic Aneurysm Repair

The inflammatory response during elective open infrarenal abdominal aortic aneurysm repair and its impact on outcome is investigated. Twenty high-risk patients were enrolled, and blood samples were obtained at 8 perioperative time points. Endotoxin, cytokines (tumor necrosis factor-alpha and interleukin-1beta, and interleukin-6), CD11b expression, and nitric oxide were measured. Peak endotoxin levels occurred within 30 minutes of reperfusion and were higher among patients developing complications. Interleukin-6 levels increased during reperfusion, reaching a peak on the first postoperative day. Interleukin-6 increase correlated with aortic clamp time and morbidity. CD11b expression increased 30 minutes after reperfusion, and this effect was greater among patients who developed complications. Endotoxin may be important in the pathogenesis of multiple organ dysfunction syndrome. Activated neutrophils may have a central role in tissue injury after reperfusion. Intraoperative CD11b upregulation may be an early marker for postoperative complications after infrarenal abdominal aortic aneurysm repair.

Positive Fluid Balance is Associated with Complications after Elective Open Infrarenal Abdominal Aortic Aneurysm Repair

Background: Open abdominal aortic aneurysm (AAA) repair is associated with cardiac and respiratory complications and an overall mortality rate of 2 to 8%. We hypothesised that excessive fluid administration during the perioperative period contributes to complications and poor outcome after AAA repair. Methods: This was a retrospective cohort study. Medical records were analysed for fluid balance and complications in 100 consecutive patients treated by open AAA repair at a single centre between 2002–2005. Mortality and all major adverse events (MAE) such as myocardial infarction (MI), cardiac arrhythmia (Arr), pulmonary oedema (PO), pulmonary infection (PI), and acute renal failure (ARF) were included in the analysis. Level of care and hospital stay, were also recorded. Results: There were no in-hospital deaths. MAE occurred in 40/100 (40%): MI (6%); Arr (14%); PO (14%); PI (25%); ARF (8%). Complications were not predicted by preoperative cardiovascular risk factors, operative and clamp time, or blood loss. Patients with complications had significantly greater cumulative positive fluid balance on postoperative day 0 (p<0.01), day 1 (p<0.05), day 2 (p<0.03) and day 3 (p<0.04). This relationship also existed for individual complications such as MI, and pulmonary oedema. These patients had significantly longer ICU/HDU (p<0.002) and hospital stay (p<0.0001). Conclusions: Serious complications are common after elective open AAA repair, and we have shown that positive fluid balance is predictive of major adverse events increased HDU/ICU and overall hospital stay.

Comparison of Risk-Scoring Methods in Predicting the Immediate Outcome after Elective Open Abdominal Aortic Aneurysm Surgery

Background & Objectives: The aim of this study was to apply three simple risk - scoring systems to prospectively collected data on all elective open Abdominal Aortic Aneurysm (AAA) operations in the Cambridge Academic Vascular Unit over a 6 - year period (January 1998 to January 2004), to compare their predictive values and to evaluate their validity with respect to prediction of mortality and post-operative complications. Methods: 204 patients underwent elective open infra-renal AAA repair. Data were prospectively collected and risk assessment scores were calculated for mortality and morbidity according to the Glasgow Aneurysm Score (GAS), VBHOM (Vascular Biochemistry and Haematology Outcome Models) and Estimation of Physiologic Ability and Surgical Stress (E-PASS). Results: The mortality rate was 6.3% (13/204) and 59% (121/204) experienced a post-operative complication (30-day outcome). For GAS, VBHOM and E-PASS the receiver operating characteristics (ROC) curve analysis for prediction of in-hospital mortality showed area under the curve (AUC) of 0.84 (95% confidence interval [CI], 0.76 to 0.92; p<0.0001), 0.82 (95% CI, 0.68 to 0.95; p=0.0001) and 0.92 (95% CI, 0.87 to 0.97; p<0.0001) respectively. There were also significant correlations between post-operative complications and length of hospital stay and each of the three scores, but the correlation was substantially higher in the case of E-PASS. Conclusions: All three scoring systems accurately predicted the risk of mortality and morbidity in patients undergoing elective open AAA repair. Among these, E-PASS seemed to be the most accurate predictor in this patient population.

Comparison of Risk-scoring Methods in Predicting the Immediate Outcome after Elective Open Abdominal Aortic Aneurysm Surgery

The aim of this study was to apply three simple risk - scoring systems to prospectively collected data on all elective open Abdominal Aortic Aneurysm (AAA) operations in the Cambridge Academic Vascular Unit over a 6 - year period (January 1998 to January 2004), to compare their predictive values and to evaluate their validity with respect to prediction of mortality and post-operative complications. 204 patients underwent elective open infra-renal AAA repair. Data were prospectively collected and risk assessment scores were calculated for mortality and morbidity according to the Glasgow Aneurysm Score (GAS), VBHOM (Vascular Biochemistry and Haematology Outcome Models) and Estimation of Physiologic Ability and Surgical Stress (E-PASS). The mortality rate was 6.3% (13/204) and 59% (121/204) experienced a post-operative complication (30-day outcome). For GAS, VBHOM and E-PASS the receiver operating characteristics (ROC) curve analysis for prediction of in-hospital mortality showed area under the curve (AUC) of 0.84 (95% confidence interval [CI], 0.76 to 0.92; p<0.0001), 0.82 (95% CI, 0.68 to 0.95; p=0.0001) and 0.92 (95% CI, 0.87 to 0.97; p<0.0001) respectively. There were also significant correlations between post-operative complications and length of hospital stay and each of the three scores, but the correlation was substantially higher in the case of E-PASS. All three scoring systems accurately predicted the risk of mortality and morbidity in patients undergoing elective open AAA repair. Among these, E-PASS seemed to be the most accurate predictor in this patient population.

Positive Fluid Balance is Associated with Complications after Elective Open Infrarenal Abdominal Aortic Aneurysm Repair

Open abdominal aortic aneurysm (AAA) repair is associated with cardiac and respiratory complications and an overall mortality rate of 2 to 8%. We hypothesised that excessive fluid administration during the perioperative period contributes to complications and poor outcome after AAA repair. This was a retrospective cohort study. Medical records were analysed for fluid balance and complications in 100 consecutive patients treated by open AAA repair at a single centre between 2002-2005. Mortality and all major adverse events (MAE) such as myocardial infarction (MI), cardiac arrhythmia (Arr), pulmonary oedema (PO), pulmonary infection (PI), and acute renal failure (ARF) were included in the analysis. Level of care and hospital stay, were also recorded. There were no in-hospital deaths. MAE occurred in 40/100 (40%): MI (6%); Arr (14%); PO (14%); PI (25%); ARF (8%). Complications were not predicted by preoperative cardiovascular risk factors, operative and clamp time, or blood loss. Patients with complications had significantly greater cumulative positive fluid balance on postoperative day 0 (p<0.01), day 1 (p<0.05), day 2 (p<0.03) and day 3 (p<0.04). This relationship also existed for individual complications such as MI, and pulmonary oedema. These patients had significantly longer ICU/HDU (p<0.002) and hospital stay (p<0.0001). Serious complications are common after elective open AAA repair, and we have shown that positive fluid balance is predictive of major adverse events increased HDU/ICU and overall hospital stay.

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.

Regarding “A prospective study of subclinical myocardial damage in endovascular versus open repair of infrarenal abdominal aortic aneurysms”

Background Endovascular repair of abdominal aortic aneurysms (AAAs) is considered to be less invasive and better tolerated by the cardiovascular system than open repair. Our aim was to assess the true incidence of perioperative myocardial damage associated with endovascular vs open infrarenal AAA repair. Methods Between July 1999 and June 2001, preoperative and postoperative serum troponin T (TnT) levels were measured in all patients presenting for elective AAA repair at Royal Prince Alfred Hospital. The incidence of myocardial damage was recorded on the basis of standard clinical, biochemical, and electrocardiographic changes or a subclinical increase of 50% or more in serum TnT. Patients were excluded if the TnT increase was associated with a significant increase of serum creatinine (≥50%) with no other evidence of myocardial ischemia. The differences between the two groups were analyzed with the χ 2 test and odds ratios. Results A total of 35 open and 112 endovascular AAA repairs were included in the study. There was no significant difference in age, sex, preoperative serum creatinine, or preoperative serum TnT between the two treatment groups. Seventeen patients had biochemical evidence of myocardial damage, which was clinically obvious in only one patient. Even though the incidence of previous myocardial infarction was significantly higher in patients undergoing endovascular repair (41%) than open repair (22%; P P Conclusions There is a previously underestimated incidence of subclinical myocardial damage associated with surgery for infrarenal AAA which is lower after endovascular than open repair.

Type IV Thoraco-Abdominal Aortic Aneurysm (TAAA IV) with Occlusion of Celiac and Superior Mesenteric Arteries in a High Risk Patient: Successful Treatment with a Hybrid Traditional Vascular and Endovascular Procedure

We describe a novel hybrid open and endovascular repair for a dumbbell shaped lower thoracic and abdominal aortic aneurysm (AAA) in a high risk patient, with celiac trunk and superior mesenteric artery occlusions. We used a two-staged approach consisting of an open infrarenal AAA repair with a by-pass to superior mesenteric artery and reimplantation of inferior mesenteric artery. This was followed by an antegrade insertion of a thoracic endograft via a PFTE graft on the thoracic aorta to allow precise deployment of the stent graft above the renal arteries.