Predictors of outcome after elective endovascular abdominal aortic aneurysm repair and external validation of a risk prediction model

Pre-operative Aortic Anatomic Features as Predictors of Clinical Outcomes Following Endovascular Repair of Abdominal Aortic Aneurysm: A Retrospective Cohort Study

ARTICLE REMOVED.

Comparative performance of three comorbidity scores in predicting survival after the elective repair of abdominal aortic aneurysms

BACKGROUND

We aimed to study the discriminative power of 3 comorbidity scores for predicting 5-year survival after the elective repair of aorto-iliac aneurysms (AAA).

METHODS

444 patients with AAA undergoing elective repair (33% open and 67% endovascular) between 2000 and 2020 were reviewed. The Charlson Comorbidity Index (CCI) and subsequent adjustments by Schneeweiss, Quan and Armitage, the Modified Frailty Index (MFI) and the American Society of Anesthesiologists Score (ASA) were calculated from preoperative data. Their association with 5-year survival was analyzed using Cox regression models and their discriminative power and its changes with C statistics and Net Reclassification Index (NRI).

RESULTS

All comorbidity scores were associated with survival after adjusting by age, sex and type of surgical repair: original CCI HR=1.24, P<0.001; Schneeweiss CCI HR=1.23, P<0.001; Quan CCI HR=1.27, P<0.001, Armitage CCI HR=1.46, P<0.001, MFI HR=1.39, P<0.001 and ASA HR=1.68 (P=0.04) and 2.86 (P=0.01) for classes III and IV, respectively. Associated C statistics were of 0.64, 0.65, 0.65, 0.64, 0.61 and 0.59, respectively. Compared with the original CCI, models based on Schneeweiss CCI and Armitage CCI provided minor improvements in NRI (0.32 and 0.23), and the model based on ASA showed lower C statistics (P=0.014) and NRI (-0.30).

CONCLUSIONS

Established comorbidity scores, such as CCI, MFI or ASA, are all associated with 5-year survival after the elective repair of AAAs, being ASA the worst of them. However, their predictive power is in no case sufficient to identify, by themselves, those patients who may not be eligible for intervention on the basis of life expectancy.

The Canadian Women's Heart Health Alliance Atlas on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 5: Sex- and Gender-Unique Manifestations of Cardiovascular Disease

This Atlas chapter summarizes sex- and some gender-associated, and unique aspects and manifestations of cardiovascular disease (CVD) in women. CVD is the primary cause of premature death in women in Canada and numerous sex-specific differences related to symptoms and pathophysiology exist. A review of the literature was done to identify sex-specific differences in symptoms, pathophysiology, and unique manifestations of CVD in women. Although women with ischemic heart disease might present with chest pain, the description of symptoms, delay between symptom onset and seeking medical attention, and prodromal symptoms are often different in women, compared with men. Nonatherosclerotic causes of angina and myocardial infarction, such as spontaneous coronary artery dissection are predominantly identified in women. Obstructive and nonobstructive coronary artery disease, aortic aneurysmal disease, and peripheral artery disease have worse outcomes in women compared with men. Sex differences exist in valvular heart disease and cardiomyopathies. Heart failure with preserved ejection fraction is more often diagnosed in women, who experience better survival after a heart failure diagnosis. Stroke might occur across the lifespan in women, who are at higher risk of stroke-related disability and age-specific mortality. Sex- and gender-unique differences exist in symptoms and pathophysiology of CVD in women. These differences must be considered when evaluating CVD manifestations, because they affect management and prognosis of cardiovascular conditions in women.

What factors counteract mid-term survival following endovascular repair of abdominal aortic aneurysms?

Introduction

Endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is increasingly used, and has become the standard treatment option for AAA.

Aim

To evaluate the outcomes and predictors of survival of endovascular treatment of AAA in the short- and medium-term.

Material and methods

A total of 222 patients having endovascular AAA repair between January 2013 and December 2019 by the same surgical team were included in the study. Patient demographics, perioperative and follow-up data including mortality, complications, and need for secondary intervention were collected. The primary endpoint was all-cause mortality. Kaplan-Meier analysis was conducted for survival and Cox regression models were assessed for predictors of survival.

Results

The median age was 70 years, with male predominance (202 patients, 91%). Thirty-day mortality was 1.8%. Median follow-up to the primary endpoint was 20 months (range: 1–80 months). Survival rates at 1, 3, and 5 years were 93.5%, 81.4%, and 62.2%, respectively. Freedom from secondary intervention rates were 95.5% at 1 year, 88.7% at 3 years, and 82.1% at 5 years. Cox proportional hazard models showed that preoperative creatinine levels ≥ 1.8 mg/dl (hazard ratio (HR) = 2.68, 95% CI: 1.21–6.42, p = 0.027), haemoglobin levels < 10 gr/dl (HR = 3.38, 95% CI: 1.16–9.90, p = 0.026), ejection fraction < 30% (HR = 5.67, 95% CI: 1.29–24.86, p = 0.021), and AAA diameter ≥ 6.0 cm (HR = 2.20, 95% CI: 1.01–4.81, p = 0.049) were independently associated with mid-term survival.

Conclusions

EVAR is a safe procedure with low postoperative morbidity and mortality. This study confirms that the mid-term survival and results are favourable. However, the analysed factors in this study that predict reduced survival (high preoperative creatinine, low haemoglobin, low ejection fraction and larger aneurysms) should be judged when planning endovascular repair of AAA.

The Spatial Morphology of Intraluminal Thrombus Influences Type II Endoleak after Endovascular Repair of Abdominal Aortic Aneurysms

INTRODUCTION

Type 2 endoleaks (T2Es) after endovascular repair (EVAR) of abdominal aortic aneurysm (AAA) can lead to sac expansion or failure of sac regression, and often present as a management dilemma. The intraluminal thrombus (ILT) may influence the likelihood of endoleaks after EVAR and can be characterized using routine preoperative imaging. We examined the relationship between preoperative spatial morphology of ILT and the incidence of postoperative T2E.

METHODS

All patients who underwent EVAR at the John Radcliffe Hospital (Oxford, UK) were prospectively entered in a clinical database. Computed tomography angiograms (CTAs) were performed as part of routine clinical care. The ILT morphology of each patient was determined using the preoperative CTA. Arterial phase cross-sectional images of the AAA were analyzed according to the presence and morphology of the thrombus in each quadrant. The overall ILT morphology was defined by measurements obtained over a 4-cm segment of the AAA. The diagnosis of T2Es during EVAR surveillance was confirmed by CTAs. The relation between the ILT morphology and T2E was assessed using logistic regression.

RESULTS

Between September 2009 and July 2016, 271 patients underwent EVAR for infrarenal AAAs (male: 241, age = 79 ± 7). The ILT was present in 265 (98%) of AAAs. Mean follow-up was 1.9 ± 1.6 years. The T2E was observed in 77 cases. Sixty-one percent of T2Es were observed within the first week after surgery. The T2E was observed in 50% (3/6) of cases without the ILT (no-ILT). Compared with no-ILT, the presence of circumferential or posterolateral ILTs was protective from T2Es (odds ratio = 0.33 and 0.37; P = 0.002 and P = 0.047, respectively).

CONCLUSIONS

The spatial ILT morphology on routine preoperative CTA imaging can be a biomarker for post-EVAR T2Es. ILTs that cover the posterolateral aspects of the lumen, or circumferential ILTs, are protective of T2Es. This information can be useful in the preoperative planning of EVARs.

Predictors of in-hospital adverse events after endovascular aortic aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) offered outstanding survival benefit but at the expense of cost, periodic radiographic monitoring, and higher reinterventions rates. Perioperative complications, although rare, can occur after EVAR, contributing to longer hospitalization, higher cost, and significant comorbidity and mortality. Therefore, the aim of this study was to identify the predictors of in-hospital events (IHEs) after elective EVAR.

METHODS

The Vascular Quality Initiative database was explored from 2003 to 2017. Patients who had converted to open repair were excluded. IHEs were defined as any in-hospital myocardial infarction, dysrhythmia, congestive heart failure (CHF), stroke, pneumonia, respiratory failure, renal failure, lower extremity ischemia, bowel ischemia, or reoperation. Stepwise backward selection based on the Akaike information criterion statistic was implemented to select the predictors of IHE from the multivariable logistic regression models. Bootstrapping was performed with 1000 replications to internally validate the model and to obtain bias-corrected estimates. Receiver operating characteristic curves (area under the curve [AUC]) and Hosmer-Lemeshow tests were used to assess the discrimination and calibration of the models.

RESULTS

A total of 28,240 patients with full information about IHEs were included. Any IHE took place in 2365 (8.4%) patients. Patients who had an IHE were slightly older (mean age ± standard deviation, 75.6 ± 8.1 years vs 73.3 ± 8.5 years; P < .001]. A higher proportion of women had an IHE (25.6% vs 17.9%; P < .001). Comorbid conditions were more prevalent in patients who developed an IHE (chronic kidney disease, 49.1% vs 33.2%; coronary artery disease, 34.3% vs 29.0%; moderate to severe CHF, 3.9% vs 1.4%; chronic obstructive pulmonary disease, 42.5% vs 31.9%; hypertension, 87.0% vs 83.1%; and diabetes, 18.0% vs 16.1%; all P ≤ .015). An IHE was associated with high in-hospital (5.6% vs 0.03%) and 30-day mortality (6.3% vs 0.3%; both P < .001) and worse 3-year survival beyond the perioperative period (81.1% [79.3%-82.9%] vs 91.1% [90.7%-91.5%]; P < .001). Two models were constructed, one from preoperative factors and the second from preoperative and intraoperative factors. The selected predictors of IHEs were female sex, moderate or severe CHF, chronic kidney disease, coronary artery disease, chronic obstructive pulmonary disease, hypertension, and aneurysm diameter. Intraoperative factors were contrast material volume, operative time, and packed red blood cell transfusion. Nomograms were constructed from the final models. AUC significantly improved after adding intraoperative factors (AUC [95% confidence interval], 0.71 [0.70-0.73] vs 0.65 [0.64-0.66]; P < .001].

CONCLUSIONS

In-hospital adverse events can complicate the perioperative course of EVAR and increase the risk of operative and long-term mortality. Predicting IHEs and identifying their risk factors can potentially mitigate their development in patients at high risk. Predicting IHE risk can have tremendous prognostic value and help disposition planning. This study introduces an internally validated tool to enable vascular surgeons to identify patients' chance of having an IHE.

Effects of Ischemic Preconditioning on Abdominal Aortic Aneurysm Repair: A Systematic Review and Meta-analysis

BACKGROUND

Ischemic preconditioning is an innate mechanism of cytoprotection against ischemia, with potential for end-organ protection. The primary goal of this study was to systematically review the literature to determine the effect of ischemic preconditioning on outcomes after open and endovascular abdominal aortic aneurysm (AAA) repair.

METHODS

The methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We included randomized clinical trials that evaluated the effect of remote ischemic preconditioning (RIPC) in reducing morbidity and mortality in patients undergoing open or endovascular AAA repair surgery. The primary outcomes were death, myocardial infarction, and renal impairment. Outcomes were addressed separately for open AAA repair and endovascular AAA repair (EVAR). Data were collected on patient characteristics, methodology, and preconditioning protocol for each trial.

RESULTS

Nine trials of ischemic preconditioning in aortic aneurysm surgery were included with a total of 599 patients; 336 patients were included in the open AAA repair meta-analysis, and 263 patients were included in the EVAR meta-analysis. For both open and endovascular repairs, ischemic preconditioning did not have a significant effect on death, myocardial infarction, or renal impairment requiring dialysis.

CONCLUSIONS

The randomized clinical trials investigating the effect of ischemic preconditioning on outcomes after open and endovascular AAA repair that have been completed to date have not been adequately powered to evaluate improvements in patient-important outcomes. The evidence is insufficient to support the use of ischemic preconditioning for AAA repair in clinical practice. The variability in treatment effect across studies may be explained by clinical and methodological heterogeneity.

Preliminary Dual-Center Experience with the Bolton Treovance Endograft

PURPOSE

To present the performance and safety of the Treovance stent graft for endovascular aortic aneurysm repair in a "real-world" patient cohort.

METHODS

Patients from 2 centers, deemed unfit for open repair, were electively treated with the Treovance endograft. Clinical preoperative, operative, and up to 1-year postoperative follow-up data of patients were retrospectively analyzed.

RESULTS

This study included 46 patients with abdominal aortic aneurysm (44 male), mean age of 78 years ± 8 standard deviation (SD; range: 58-93 years). All met the manufacturer's recommended anatomical requirements: average maximum sac diameter 63 mm ± 10 SD (range: 52-86 mm), proximal neck length 29 mm ± 12 SD (range: 11-60 mm), and neck angulation 30° ± 21 SD (range: 0°-70°). Fourteen had moderate to severe iliac tortuosity. A primary technical success rate of 80% was achieved (100% assisted primary technical success rate): 7 patients required adjunctive procedures intraoperatively and 2 successful treatments for type I endoleaks, which occurred within 24 hours postoperatively. There was 100% survival at 1-year follow-up; however, 4 (8.7%) patients required reintervention: 1 for a type I endoleak, 2 for limb stenosis, and 1 for a type II endoleak with an enlarging sac. No other device-related complications were identified. Reintervention and complication rates in hostile versus nonhostile anatomies were not statistically significant ( P = .28 and P = .42, respectively).

CONCLUSION

The Treovance stent graft has a comparable safety profile to other next-generation stent grafts during the first year after endovascular aneurysm repair, which provides a rationale for further interrogation of its outcomes through clinical trials.

Systematic review of mortality risk prediction models in the era of endovascular abdominal aortic aneurysm surgery

BACKGROUND

The introduction of endovascular aneurysm repair (EVAR) has reduced perioperative mortality after abdominal aortic aneurysm (AAA) surgery. The objective of this systematic review was to assess existing mortality risk prediction models, and identify which are most useful for patients undergoing AAA repair by either EVAR or open surgical repair.

METHODS

A systematic search of the literature was conducted for perioperative mortality risk prediction models for patients with AAA published since 2006. PRISMA guidelines were used; quality was appraised, and data were extracted and interpreted following the CHARMS guidelines.

RESULTS

Some 3903 studies were identified, of which 27 were selected. A total of 13 risk prediction models have been developed and directly validated. Most models were based on a UK or US population. The best performing models regarding both applicability and discrimination were the perioperative British Aneurysm Repair score (C-statistic 0·83) and the preoperative Vascular Biochemistry and Haematology Outcome Model (C-statistic 0·85), but both lacked substantial external validation.

CONCLUSION

Mortality risk prediction in AAA surgery has been modelled extensively, but many of these models are weak methodologically and have highly variable performance across different populations. New models are unlikely to be helpful; instead case-mix correction should be modelled and adapted to the population of interest using the relevant mortality predictors.

A Systematic Review of Predictors of Reintervention After EVAR: Guidance for Risk-Stratified Surveillance

BACKGROUND

Current surveillance protocols after endovascular aneurysm repair (EVAR) are ineffective and costly. Stratifying surveillance by individual risk of reintervention requires an understanding of the factors involved in developing post-EVAR complications. This systematic review assessed risk factors for reintervention after EVAR and proposals for stratified surveillance.

METHODS

A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting on risk factors predicting reintervention after EVAR and proposals for stratified surveillance.

RESULTS

Twenty-nine studies reporting on 39 898 patients met the primary inclusion criteria for reporting predictors of reintervention or aortic complications with or without suggestions for stratified surveillance. Five secondary studies described external validation of risk scores for reintervention or aortic complications. There was great heterogeneity in reporting risk factors identified at the pre-EVAR, intraoperative, and post-EVAR stages of treatment, although large preoperative abdominal aortic aneurysm diameter was the most commonly observed risk factor for reintervention after EVAR.

CONCLUSION

Existing data on predictors of post-EVAR complications are generally of poor quality and largely derived from retrospective studies. Few studies describing suggestions for stratified surveillance have been subjected to external validation. There is a need to refine risk prediction for EVAR failure and to conduct prospective comparative studies of personalized surveillance with standard practice.

An anatomic risk model to screen post endovascular aneurysm repair patients for aneurysm sac enlargement

BACKGROUND

Follow-up computed tomography angiography (CTA) scans add considerable postimplantation costs to endovascular aneurysm repairs (EVARs) of abdominal aortic aneurysms (AAAs). By building a risk model, we hope to identify patients at low risk for aneurysm sac enlargement to minimize unnecessary CTAs.

METHODS

895 consecutive patients who underwent EVAR for AAA were reviewed, of which 556 met inclusion criteria. A Probit model was created for aneurysm sac enlargement, with preoperative aneurysm morphology, patient demographics, and operative details as variables.

RESULTS

Our final model included 287 patients and had a sensitivity of 100%, a specificity of 68.9%, and an accuracy of 70.4%. Ninety-nine (35%) of patients were assigned to the high-risk group, whereas 188 (65%) of patients were assigned to the low-risk group. Notably, regarding anatomic variables, our model reported that age, pulmonary comorbidities, aortic neck diameter, iliac artery length, and aneurysms were independent predictors of post-EVAR sac enlargement. With the exception of age, all statistically significant variables were qualitatively supported by prior literature. With regards to secondary outcomes, the high-risk group had significantly higher proportions of AAA-related deaths (5.1% versus 1.1%, P = 0.037) and Type 1 endoleaks (9.1% versus 3.2%, P = 0.033).

CONCLUSIONS

Our model is a decent predictor of patients at low risk for post AAA EVAR aneurysm sac enlargement and associated complications. With additional validation and refinement, it could be applied to practices to cut down on the overall need for postimplantation CTA.

Survival After Endovascular Abdominal Aortic Aneurysm Repair in a Population with a Low Incidence of Coronary Artery Disease

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) is a prophylactic procedure, so the decision to operate should consider, as recent guidelines suggest, the life expectancy of the patient. Several models for predicting life span have been already designed, but little is known about how intervened patients evolve in Southern European Countries, where the incidence of coronary artery disease, the main cause of death among these subjects, is low.

METHODS

We conducted a retrospective analysis of 176 consecutive patients who underwent elective EVAR at the Vascular Surgery Department of the Hospital del Mar (Barcelona, Spain) during 2000-2014. Cox regressions were performed to identify preoperative factors associated with long-term survival after EVAR, and a risk model was developed.

RESULTS

Three- and five-year survival rates were 73.9 and 53.9 %, respectively. During the follow-up, 72 deaths (40.9 %) were registered, cancer being the most frequent cause (41.7 %). Preoperative variables negatively associated with long-term survival were serum creatinine ≥ 150 µmol/L (HR 2.5; 95 % CI 1.4-4.2), chronic obstructive pulmonary disease (HR 1.9; 95 % CI 1.2-3.1), atrial fibrillation (HR 2.0; 95 % CI 1.2-3.4), and prior cancer history (HR 1.9; 95 % CI 1.2-3.1). Distal pulses present in both lower limbs were marginally associated with survival (HR 0.65; 95 % CI 0.4-1.07). The survival predictive model showed a good discrimination capacity (C statistic = 0.703; 95 % CI 0.641-0.765).

CONCLUSIONS

Long-term survival of patients submitted to EVAR in our setting was worse than expected and markedly related to cancer. Our study suggests that predictive models for long-term survival after EVAR may be influenced by regional characteristics of the intervened population. This effect should be taken in consideration in the decision-making process of these patients.

Endovascular versus open repair of ruptured abdominal aortic aneurysm

INTRODUCTION

Endovascular aneurysm repair (EVAR) is a comparatively less invasive technique than open repair (OR). Debate remains with regard to the benefit of EVAR for patients with ruptured abdominal aortic aneurysm (RAAA). We sought to evaluate and report outcomes of EVAR for RAAA in an Irish tertiary vascular referral centre.

METHODS

Patients undergoing emergency surgery for ruptured or symptomatic AAA were identified from theatre logbooks and HIPE database. Retrospective chart review was undertaken. Data were exported to IBM SPSS version 21 for statistical analysis with p < 0.05 considered significant.

RESULTS

A total of 41 patients underwent surgery for RAAA. The mean age was 74 years old with a range from 55 to 89 years. The majority (n = 25, 61%) were baseline American Society of Anaesthesiology (ASA) grade 3-4. Of these 56% underwent EVAR with the remaining 44% repaired open. Mortality rate in those undergoing emergency EVAR was 34.8%, compared with 38.9% in those undergoing open surgery. This difference was not statistically significant. The mean overall length of stay was 13 days. With regard to prognostic indicators of patient outcome, increasing patient age was noted to be significantly associated with increased mortality (p = 0.013), as was increased ASA score at time of surgery (p = 0.029).

CONCLUSIONS

Mortality rates in those undergoing EVAR for RAAA are comparable with those undergoing open repair. Increasing age and ASA score are significant predictors of mortality in patients with RAAA undergoing intervention.

Novel Risk Score Model for Prediction of Survival Following Elective Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

The purpose of this study was to identify significant predictors of long-term mortality after elective endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

We included all cases with elective EVAR based on a national data set from the Society for Vascular Surgery Patient Safety Organization. Clinical and anatomic variables were analyzed with a Kaplan-Meier and Cox-regression model to determine predictors of mortality and develop a score equation to categorize patients into low, medium, and high long-term mortality risk.

RESULTS

A total of 5678 patients with EVAR were included with an average age of 73.6 ± 8.2 years. The majority were male (81.6%) with a history of smoking (86.1%). There were 3 deaths within 30 days (0.1%). Several factors were associated with poor survival: unstable angina (hazard ratio [HR], 2.8; P = .008), dialysis (HR, 3.7; P < .001), estimated glomerular filtration rate (eGFR) <30 (HR, 1.7; P = .044), eGFR 30 to 59 (HR, 1.4; P = .002), age >80 (HR, 3.2; P < .001), age 75 to 79 (HR, 2.2; P < .001), chronic obstructive pulmonary disease on oxygen (HR, 3.3; P < .001), aortic diameter >5.8 cm (HR, 1.2; P = .043), and high risk for surgery (HR, 1.4; P = .043). Preoperative aspirin use and body mass index 25 to 35 were both found to be protective (HR, 0.78; P = .017 and HR, 0.8; P = .024, respectively). With our scoring model, 5- and 10-year survival rates for patients with low, medium, and high risk were 89.2%, 80.7%, and 64.1% and 77.2%, 60.1%, and 40.1%, respectively (P < .001).

CONCLUSION

Ten-year survival following EVAR in patients with a high-risk score utilizing the model provided was 40.1%. Patients with multiple comorbidities at risk for decreased long-term survival can be identified with our model, which is more applicable for high-volume contemporary institutions.

The Concept of Risk Assessment and Being Unfit for Surgery

The concept of risk assessment and the identification of surgical unfitness for vascular intervention is a particularly controversial issue today as the minimally invasive surgical population has increased not only in volume but also in complexity (comorbidity profile) and age, requiring an improved pre-operative selection and definition of high risk. A practical step by step (three steps, two points for each) approach for surgical risk assessment is suggested in this review. As a general rule, the identification of a "high risk" patient for vascular surgery follows a step by step process where the risk is clearly defined, quantified (when too "high"?), and thereby stratified based on the procedure, the patient, and the hospital, with the aid of predictive risk scores. However, there is no standardized, updated, and objective definition for surgical unfitness today. The major gap in the current literature on the definition of high risk in vascular patients explains the lack of sound validated predictive systems and limited generalizability of risk scores in vascular surgery. In addition, the concept of fitness is an evolving tool and many traditional high risk criteria and definitions are no longer valid. Given the preventive purpose of most vascular procedures performed in elderly asymptomatic patients, the decision to pursue or withhold surgery requires realistic estimates not only regarding individual peri-operative mortality, but also life expectancy, healthcare priorities, and the patient's primary goals, such as prolongation of life versus maintenance of independence or symptom relief. The overall "frailty" and geriatric risk burden, such as cognitive, functional, social, and nutritional status, are variables that should be also included in the analyses for stratification of surgical risk in elderly vascular patients.

Preoperative Predictors of Long-Term Mortality after Elective Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

OBJECTIVE

This study aimed to clarify long-term mortality and its predictors in patients with abdominal aortic aneurysm (AAA) who underwent endovascular aneurysm repair (EVAR).

MATERIALS AND METHODS

Patients with AAA who underwent elective EVAR at Tokyo Medical and Dental University hospital between 2008 and 2011 were reviewed. The patients' data were retrospectively collected from medical records.

RESULTS

Sixty-four patients were identified for this study. In long-term follow-up, the survival rate was significantly lower in patients with high preoperative C-reactive protein (CRP) levels. Patients with obstructive lung disease (FEV1/FVC <70%) or anemia tended to have a poorer prognosis but the association was not statistically significant. Age, concurrent hyperlipidemia, and blood pressure levels were not predictors of mortality rates.

DISCUSSION

High CRP level, COPD, and anemia reflect inflammation, which is associated with the pathogenesis of AAA. These inflammatory markers are predictors of long-term mortality after EVAR for AAA as well as for other diseases.

CONCLUSIONS

A high preoperative CRP level was a predictor of increased long-term mortality in patients with AAA who underwent EVAR. No specific leading causes of death were identified for this increase in the mortality rate.

The effect of anatomical factors on mortality rates after endovascular aneurysm repair

Objective

The objective of this study was to investigate the effect of anatomical characteristics on mortality rates after endovascular aneurysm repair (EVAR).

Methods

We investigated 56 EVAR procedures for infrarenal aortic aneurysms performed between January 2010 and December 2013, and the data were supplemented with a prospective review. The patients were divided into two groups according to the diameter of the aneurysm. Group I (n = 30): patients with aneurysm diameters less than 6 cm, group II (n = 26): patients with aneurysm diameters larger than 6 cm. The pre-operative anatomical data of the aneurysms were noted and the groups were compared with regard to postoperative results.

Results

There were no correlations between diameter of aneurysm (p > 0.05), aneurysm neck angle (p > 0.05) and mortality rate. The long-term mortality rate was found to be high in patients in whom an endoleak occurred.

Conclusion

We found that aneurysm diameter did not have an effect on postoperative mortality rates. An increased EuroSCORE value and the development of endoleaks had an effect on long-term mortality rates.

A meta-analysis of the predictive accuracy of postoperative mortality using the American Society of Anesthesiologists' physical status classification system

BACKGROUND

The American Society of Anesthesiologists' physical status (ASA) tool has been applied to determine compensation, risk adjustment and risk prediction, but little is known about the accuracy and generalizability of this tool for prediction of postoperative mortality.

METHODS

We systematically investigated prior published reports of associations between ASA physical status and mortality to test the hypothesis that ASA physical status will have varying accuracy in prediction of postoperative mortality across surgical populations with varying surgical risk of mortality. We used random effects models and metaregression to account for heterogeneity.

RESULTS

Combining 77 studies with 165,705 patients, the ASA physical status tool demonstrated the following pooled performance (95 % confidence intervals)--sensitivity 0.74 (0.73, 0.74), specificity 0.67 (0.67, 0.67), and area under summary receiver operating curve 0.736 (0.725, 0.747). Metaregression revealed that study death rates and surgical specialty were significant factors.

CONCLUSION

ASA physical status is a better predictor of postoperative mortality in settings with lower rather than higher death rates.

Postoperative "Chimney" for Unintentional Renal Artery Occlusion after EVAR

Renal artery obstruction during endovascular repair of abdominal aortic aneurysm using standard device is a rare but life-threatening complication and should be recognized and repaired rapidly in order to maintain renal function. Both conventional surgery and endovascular stenting have been reported. We report a case of late postoperative bilateral “chimney” to resolve a bilateral thrombosis of the renal artery following an uncomplicated endovascular aortic repair.

Effect of age on survival between open repair and surveillance for small abdominal aortic aneurysms

Randomized controlled trials have shown no significant difference in survival between immediate open repair and surveillance with selective repair for asymptomatic abdominal aortic aneurysms of 4.0 to 5.5 cm in diameter. This lack of difference has been shown to hold true for all diameters in this range, in men and women, but the question of whether patients of different ages might obtain different benefits has remained unanswered. Using the pooled patient-level data for the 2,226 patients randomized to immediate open repair or surveillance in the United Kingdom Small Aneurysm Trial (UKSAT; September 1, 1991, to July 31, 1998; follow-up 2.6 to 6.9 years) or the Aneurysm Detection and Management (ADAM) trial (August 1, 1992, to July 31, 2000; follow-up 3.5 to 8.0 years), the adjusted effect of age on survival in the 2 treatment groups was estimated using a generalized propensity approach, accounting for a comprehensive array of clinical and nonclinical risk factors. No significant difference in survival between immediate open repair and surveillance was observed for patients of any age, overall (p = 0.606) or in men (p = 0.371) or women separately (p = 0.167). In conclusion, survival did not differ significantly between immediate open repair and surveillance for patients of any age, overall or in men or women. Combined with the previous evidence regarding diameter, and the lack of benefit of immediate endovascular in trials comparing it with surveillance repair for small abdominal aortic aneurysms, these results suggest that surveillance should be the first-line management strategy of choice for asymptomatic abdominal aortic aneurysms of 4.0 to 5.5 cm.

Immediate open repair vs surveillance in patients with small abdominal aortic aneurysms: survival differences by aneurysm size

OBJECTIVE

To assess whether survival differences exist between patients undergoing immediate open repair vs surveillance with selective repair for 4.0- to 5.4-cm abdominal aortic aneurysms (AAAs) and whether these differences vary by diameter, within sexes, or overall.

PATIENTS AND METHODS

The study cohort included 2226 patients randomized to immediate repair or surveillance for the UK Small Aneurysm Trial (September 1, 1991, through July 31, 1998; follow-up, 2.6-6.9 years) or the Aneurysm Detection and Management trial (August 1, 1992, through July 31, 2000; follow-up, 3.5-8.0 years). Survival differences were assessed with proportional hazard models, adjusted for a comprehensive array of clinical and nonclinical risk factors. Interaction between treatment and AAA size was added to the model to assess whether the effect of immediate open repair vs surveillance varied by AAA size.

RESULTS

The adjusted analysis revealed no statistically significant survival difference between immediate open repair and surveillance patients (hazard ratio [HR], 0.99; 95% CI, 0.83-1.18; mean follow-up time, 1921 days for both study groups). This lack of treatment effect persisted when men (HR, 1.01; 95% CI, 0.84-1.21) and women (HR, 0.96; 95% CI, 0.49-1.86) were examined separately and did not vary by AAA size (P=.39 for the entire cohort and P=.24 for women).

CONCLUSION

Immediate open repair offered no significant survival benefit, even in patients with the largest AAAs and highest risk of rupture. Because recent trials failed to find a survival benefit of immediate endovascular repair over surveillance for small asymptomatic AAAs, our findings suggest that the gray area of first-line management for these patients should be resolved in favor of surveillance.

Sex differences in 30-day and 5-year outcomes after endovascular repair of abdominal aortic aneurysms in the EUROSTAR study

OBJECTIVE

The purpose of this study was to determine the effect of sex on 30-day and long-term outcomes after elective endovascular aneurysm repair.

METHODS

Patients entered into the European collaborators on stent graft techniques for abdominal aortic aneurysm repair (EUROSTAR) study formed the basis of our study. Data were analyzed by means of multivariable logistic regression for 30-day mortality and composite outcome of mortality, systemic complication, or conversion. Kaplan-Meier survival analyses were used to compare long-term survival and long-term event-free survival times between women and men. The log-rank test was used to test for differences. Cox proportional hazards regression was used to analyze survival and event-free survival (with end point mortality or reintervention). Multivariable analyses were adjusted for age, comorbidities, aneurysm characteristics, and treatment characteristics.

RESULTS

There were 623 women and 8604 men available for analysis. No difference in 30-day mortality was demonstrated for women compared with men (odds ratio, 0.89; 95% confidence interval [CI], 0.48-1.67), but women did have a significantly higher cumulative incidence of the composite end point (odds ratio, 1.32; 95% CI, 1.05-1.66). The Kaplan-Meier curves demonstrated worse outcomes for both long-term survival (P = .05) and long-term event-free survival (P =.005). Survival analyses adjusting for covariates demonstrated a higher albeit nonsignificant difference in long-term mortality for women compared to men (hazard rate ratio, 1.21; 95% CI, 0.96-1.53) and a significant higher rate of the composite end point mortality or reintervention (hazard rate ratio, 1.28; 95% CI, 1.07-1.54).

CONCLUSIONS

Women undergoing endovascular aortic repair have higher complication and reintervention rates compared with men, implying that the role of elective endovascular aneurysm repair in women needs to be examined more closely.

Role of pre-operative multiple gated acquisition scanning in predicting long-term outcome in patients undergoing elective abdominal aortic aneurysm repair

OBJECTIVE

To determine whether resting pre-operative left ventricular ejection fraction (LVEF) estimated by multiple gated acquisition scanning (MUGA) predicts long-term survival in patients undergoing elective abdominal aortic aneurysm (AAA) repair.

METHODS

A retrospective study of MUGA scans which were performed to estimate pre-operative resting LVEF in 127 patients [106 (83 %) males, mean age 74 ± 7.6 years] who underwent elective AAA repair over a period of 4 years from March 2007. We compared outcomes and long-term survival between patients who had a pre-operative LVEF ≤ 40 % (Group 1, n = 60) and LVEF > 40 % (Group 2, n = 67).

RESULTS

Overall 19 (15 %) patients died during the follow-up period (13 patients in group 1 and 6 patients in group 2). 30-day mortality was 8 %. There was no significant difference between group 1 and 2 in terms of patients' mean age or median length of hospital stay (8 days for both groups, p = 0.61). However, group 2 had more females than group 1(18 vs. 3, p = 0.001). Median survival for patients in group 2 was significantly higher than patients in group 1 (1,258 days vs. 1,000 days, p = 0.03). In a Cox regression model which included age, sex, smoking status and LVEF as covariates, only smoking status and LVEF predicted survival [Hazard ratio (HR) = 1.06, p = 0.04 and HR = 0.93, p = 0.00, respectively].

CONCLUSION

This study shows that there is a role for pre-operative MUGA scan assessment of resting LVEF in predicting long-term survival post elective AAA repair and that the lower the pre-operative LVEF the poorer the long-term outcome.

Effect of Preoperative Aneurysm Diameter on Long-Term Survival After Endovascular Aortic Aneurysm Repair

Objective: To investigate the effect of aneurysm size on long-term survival after endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs). Methods: Retrospective study of all consecutive patients treated with EVAR for AAA at a single institution. Results: One hundred and nineteen patients (mean age 71, range 45-91) underwent EVAR during a 4-year period. The mean maximal aneurysm diameter was 58 mm (range 34-93 mm). Mean follow-up was 34 months (range 1-80). Cox regression analysis after controlling for age, renal function, coronary disease, and smoking showed a 4.9-fold higher risk of death for patients with preoperative aneurysm size ≥60 mm as compared to patients with aneurysm size <60 mm. No aneurysm-related deaths occurred during the follow-up. Conclusion: This present study provides evidence that aneurysm size ≥60 mm is independently associated with worse survival during follow-up.

Submaximal exercise testing predicts perioperative hospitalization after aortic aneurysm repair

BACKGROUND

Aortic aneurysm repair is a high-risk surgical procedure. Patients are often elderly, with multiple comorbidities that predispose them to perioperative morbidity. Use of endovascular aneurysm repair (EVAR) has increased due to reduced early perioperative risk. This study assessed whether preoperative cardiopulmonary exercise testing (CPET) could be used to predict morbidity and hospital length of stay (LOS) after aortic aneurysm repair.

METHODS

A total of 185 patients underwent surgical repair (84 open repairs, 101 EVAR) and had adequate determination of a submaximal CPET parameter (anaerobic threshold).

RESULTS

Patient comorbidities and cardiorespiratory fitness, derived from CPET, were similar between surgical procedures. Patients undergoing EVAR had fewer complications (10% vs 32%; P<.0001) and shorter mean (standard deviation [SD]) hospital LOS of 5.7 (9.3) days vs 14.4 (10.9) days compared with open repair (P<.0001). The hospital LOS was significantly increased in patients with one or more complications in both groups compared with those with no complications. In the open repair group, the level of fitness, as defined by anaerobic threshold, was an independent predictor of postoperative morbidity and hospital LOS. When the optimal anaerobic threshold (10 mL/min/kg) derived from receiver operator curve analysis was used as a cutoff value, unfit patients stayed significantly longer than fit patients in critical care (mean, 6.4 [SD, 6.9] days vs 2.4 [SD, 2.9] days; P=.002) and in the hospital (mean, 23.1 [SD, 14.8] days vs 11.0 [SD, 6.1] days; P<.0001). In contrast, fitness in the EVAR group was not predictive of postoperative morbidity but did have predictive value for hospital LOS.

CONCLUSIONS

Cardiorespiratory fitness holds significant clinical value before aortic aneurysm repair in predicting postsurgical complications and duration of critical care and hospital LOS. Preoperative measurement of fitness could then direct clinical management with regard to operative choice, postoperative resource allocation, and informed patient decision making.