Endovascular stent grafting versus open surgical operation in patients with infrarenal aortic aneurysms: a propensity score-adjusted analysis

In-hospital thromboembolic complications after frozen elephant trunk aortic arch repair

OBJECTIVE

This study evaluated the frequency and clinical impact of thromboembolic complications after frozen elephant trunk aortic arch repair using the Thoraflex device (Terumo Aortic).

METHODS

A total of 128 consecutive patients (mean age 67.9 ± 13.7 years, 31.0% female) underwent frozen elephant trunk aortic arch repair using the Thoraflex device between September 2014 and May 2021 in 4 Canadian centers. Patient baseline characteristics, intraoperative details, and frozen elephant trunk thromboembolic complications were collected retrospectively and analyzed.

RESULTS

Fifteen patients (11.7%) had thrombus visualized within the frozen elephant trunk stent graft on imaging (n = 8; 53.3%) or had a thromboembolic event (n = 9; 60.0%) before hospital discharge. Sites of embolism were mesenteric (n = 8; 88.9%), renal (n = 4; 44.4%), and iliofemoral (n = 1; 11.1%). Patients who experienced thromboembolic complications were more likely to have a history of autoimmune disease (n = 3; 20.0% vs n = 2; 1.8%; P = .01) and implantation of a longer frozen elephant trunk stent graft (150 mm vs 100 mm) (n = 13; 86.7% vs n = 45; 39.8%; P < .001). All patients with thromboembolic complications received therapeutic anticoagulation, and a smaller proportion required an open surgical (n = 5; 33.3%) or an endovascular (n = 2; 13.3%) intervention. Radiographic resolution of thromboembolic complications was observed in 86.7% of patients (n = 13). In-hospital mortality occurred in 1 patient, stroke occurred in 1 patient, and transient spinal cord injury occurred in 1 patient.

CONCLUSIONS

Thromboembolic complications occur more often than previously recognized after frozen elephant trunk aortic arch repair using the Thoraflex device and are associated with increased rates of surgical and endovascular reintervention. Prevention and management of these complications require further study.

Radiometal chelators for infection diagnostics

Infection of native tissues or implanted devices is common, but clinical diagnosis is frequently difficult and currently available noninvasive tests perform poorly. Immunocompromised individuals (for example transplant recipients, or those with cancer) are at increased risk. No imaging test in clinical use can specifically identify infection, or accurately differentiate bacterial from fungal infections. Commonly used [18F]fluorodeoxyglucose (18FDG) positron emission computed tomography (PET/CT) is sensitive for infection, but limited by poor specificity because increased glucose uptake may also indicate inflammation or malignancy. Furthermore, this tracer provides no indication of the type of infective agent (bacterial, fungal, or parasitic). Imaging tools that directly and specifically target microbial pathogens are highly desirable to improve noninvasive infection diagnosis and localization. A growing field of research is exploring the utility of radiometals and their chelators (siderophores), which are small molecules that bind radiometals and form a stable complex allowing sequestration by microbes. This radiometal-chelator complex can be directed to a specific microbial target in vivo, facilitating anatomical localization by PET or single photon emission computed tomography. Additionally, bifunctional chelators can further conjugate therapeutic molecules (e.g., peptides, antibiotics, antibodies) while still bound to desired radiometals, combining specific imaging with highly targeted antimicrobial therapy. These novel therapeutics may prove a useful complement to the armamentarium in the global fight against antimicrobial resistance. This review will highlight current state of infection imaging diagnostics and their limitations, strategies to develop infection-specific diagnostics, recent advances in radiometal-based chelators for microbial infection imaging, challenges, and future directions to improve targeted diagnostics and/or therapeutics.

Surveillance Imaging following Endovascular Aneurysm Repair: State of the Art

Endovascular aneurysmal repair (EVAR) has become a prominent modality for the treatment of abdominal aortic aneurysm. Surveillance imaging is important for the detection of device-related complications, which include endoleak, structural abnormalities, and infection. Currently used modalities include ultrasound, X-ray, computed tomography, magnetic resonance imaging, and angiography. Understanding the advantages and drawbacks of each modality, as well available guidelines, can guide selection of the appropriate technique for individual patients. We review complications following EVAR and advances in surveillance imaging modalities.

Meta-analysis of phase-specific survival after elective endovascular versus surgical repair of abdominal aortic aneurysm from randomized controlled trials and propensity score-matched studies

OBJECTIVE

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) significantly decreases perioperative mortality compared with open surgical repair (OSR), we have not concluded superiority between EVAR and OSR beyond the perioperative period. The aim of this study was to compare phase-specific survival after EVAR vs OSR.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Embase and MEDLINE were searched up to November 2019 to identify randomized controlled trials and propensity score-matched studies that investigated ≥2-year all-cause mortality (primary outcome) after EVAR vs OSR for intact infrarenal AAA. For each study, the hazard ratio (HR) with 95% confidence interval (CI) of mortality for EVAR vs OSR was calculated using survival curves for the following specific phases: early term (0-2 years after repair), midterm (2-6 years after repair), long term (6-10 years after repair), and very long term (≥10 years after repair). The risk ratio (RR) in the perioperative (in-hospital or 30-day) period was also extracted. Phase-specific HRs or RRs were separately pooled using the random effects model. Sensitivity analyses were performed by removing one study at a time to confirm that our findings were not derived from any single study. Funnel plot asymmetry was also examined using the linear regression test.

RESULTS

Our search identified four randomized controlled trials and seven propensity score-matched studies enrolling a total of 106,243 AAA patients assigned to EVAR (n = 53,123) or OSR (n = 53,120). The mortality after EVAR compared with OSR was significantly lower in the perioperative period (RR, 0.39; 95% CI, 0.29-0.51; P < .00001) and similar in the early-term period (HR, 0.93; 95% CI, 0.84-1.03; P = .16). Notably, significantly higher mortality was observed in the EVAR group compared with the OSR group in the midterm period (HR, 1.15; 95% CI, 1.03-1.29; P = .01). However, similar mortality was observed between the EVAR group and the OSR group in the long-term (HR, 1.06; 95% CI, 0.96-1.17; P = .27) and very-long-term (HR, 1.17; 95% CI, 0.93-1.47; P = .19) periods. In sensitivity analyses, the significant benefit of EVAR in the perioperative period and that of OSR in the midterm period were not changed. No funnel plot asymmetry was identified in all analyses.

CONCLUSIONS

Compared with OSR, EVAR was associated with lower perioperative mortality and higher mortality in the midterm period for intact infrarenal AAA. The superiority of EVAR was absent in the early-term period, and the inferiority of EVAR in the midterm period disappeared in the long-term and very-long-term periods.

Complications of endovascular aneurysm repair of the thoracic and abdominal aorta: evaluation and management

In recent decades, endovascular aneurysm repair or endovascular aortic repair (EVAR) has become an acceptable alternative to open surgery for the treatment of thoracic and abdominal aortic aneurysms and other aortic pathologies such as the acute aortic syndromes (e.g., penetrating aortic ulcer, intramural hematoma, dissection). Available data suggest that endovascular repair is associated with lower perioperative 30-day all-cause mortality as well as a significant reduction in perioperative morbidity when compared to open surgery. Additionally, EVAR leads to decreased blood loss, eliminates the need for cross-clamping the aorta and has shorter recovery periods than traditional surgery. It is currently the preferred mode of treatment of thoracic and abdominal aortic aneurysms in a subset of patients who meet certain anatomic criteria conducive to endovascular repair. The main disadvantage of EVAR procedures is the high rate of post-procedural complications that often require secondary re-intervention. As a result, most authorities recommend lifelong imaging surveillance following repair. Available surveillance modalities include conventional radiography, computed tomography, magnetic resonance angiography, ultrasonography, nuclear imaging and conventional angiography, with computed tomography currently considered to be the gold standard for surveillance by most experts. Following endovascular abdominal aortic aneurysm (AAA) repair, the rate of complications is estimated to range between 16% and 30%. The complication rate is higher following thoracic EVAR (TEVAR) and is estimated to be as high as 38%. Common complications include both those related to the endograft device and systemic complications. Device-related complications include endoleaks, endograft migration or collapse, kinking and/or stenosis of an endograft limb and graft infection. Post-procedural systemic complications include end-organ ischemia, cerebrovascular and cardiovascular events and post-implantation syndrome. Secondary re-interventions are required in approximately 19% to 24% of cases following endovascular abdominal and thoracic aortic aneurysm repair respectively. Typically, most secondary reinterventions involve the use of percutaneous techniques such as placement of cuff extension devices, additional endograft components or stents, enhancement of endograft fixation, treatment of certain endoleaks using various embolization techniques and embolic agents and thrombolysis of occluded endograft components. Less commonly, surgical conversion and/or open surgical modification are required. In this article, we provide an overview of the most common complications that may occur following endovascular repair of thoracic and AAAs. We also summarize the current surveillance recommendations for detecting and evaluating these complications and discuss various current secondary re-intervention approaches that may typically be employed for treatment.

Systematic Review and Meta-analysis of Factors Influencing Survival Following Abdominal Aortic Aneurysm Repair

BACKGROUND

Predicting long-term survival following repair is essential to clinical decision making when offering abdominal aortic aneurysm (AAA) treatment. A systematic review and a meta-analysis of pre-operative non-modifiable prognostic risk factors influencing patient survival following elective open AAA repair (OAR) and endovascular aneurysm repair (EVAR) was performed.

METHODS

MEDLINE, Embase and Cochrane electronic databases were searched to identify all relevant articles reporting risk factors influencing long-term survival (≥1 year) following OAR and EVAR, published up to April 2015. Studies with <100 patients and those involving primarily ruptured AAA, complex repairs (supra celiac/renal clamp), and high risk patients were excluded. Primary risk factors were increasing age, sex, American Society of Anaesthesiologist (ASA) score, and comorbidities such as ischaemic heart disease (IHD), cardiac failure, hypertension, chronic obstructive pulmonary disease (COPD), renal impairment, cerebrovascular disease, peripheral vascular disease (PVD), and diabetes. Estimated risks were expressed as hazard ratio (HR).

RESULTS

A total of 5,749 study titles/abstracts were retrieved and 304 studies were thought to be relevant. The systematic review included 51 articles and the meta-analysis 45. End stage renal disease and COPD requiring supplementary oxygen had the worst long-term survival, HR 3.15 (95% CI 2.45-4.04) and HR 3.05 (95% CI 1.93-4.80) respectively. An increase in age was associated with HR of 1.05 (95% CI 1.04-1.06) for every one year increase and females had a worse survival than men HR 1.15 (95% CI 1.07-1.27). An increase in ASA score and the presence of IHD, cardiac failure, hypertension, COPD, renal impairment, cerebrovascular disease, PVD, and diabetes were also factors associated with poor long-term survival.

CONCLUSION

The result of this meta-analysis summarises and quantifies unmodifiable risk factors that influence late survival following AAA repair from the best available published evidence. The presence of these factors might assist in clinical decision making during discussion with patients regarding repair.

The Abdominal Aortic Aneurysm and Intraluminal Thrombus: Current Concepts of Development and Treatment

The pathogenesis of the abdominal aortic aneurysm (AAA) shows several hallmarks of atherosclerotic and atherothrombotic disease, but comprises an additional, predominant feature of proteolysis resulting in the degradation and destabilization of the aortic wall. This review aims to summarize the current knowledge on AAA development, involving the accumulation of neutrophils in the intraluminal thrombus and their central role in creating an oxidative and proteolytic environment. Particular focus is placed on the controversial role of heme oxygenase 1/carbon monoxide and nitric oxide synthase/peroxynitrite, which may exert both protective and damaging effects in the development of the aneurysm. Treatment indications as well as surgical and pharmacological options for AAA therapy are discussed in light of recent reports.

A propensity score-matching analysis of transthoracic echocardiography and abdominal ultrasonography for the detection of abdominal aortic aneurysms

INTRODUCTION

We previously reported that the prevalence of abdominal aortic aneurysms (AAAs) was higher in patients undergoing scheduled transthoracic echocardiography (TTE) than in patients undergoing abdominal ultrasonography (AUS); however, intergroup patient backgrounds differed significantly in that report.

PURPOSE

We tested the hypothesis that TTE could detect AAA as effectively as AUS.

DESIGN

A propensity score-matching analysis of a cross-sectional study was adopted as the design for this study.

METHODS

We enrolled 7,619 and 15,433 patients scheduled to undergo TTE with additional evaluation of abdominal aorta at the end of the routine study and AUS, respectively, from 2009 to 2010 in our hospital, as reported. A propensity score for profiles of patients who underwent TTE or AUS was developed to adjust for potential confounding bias. Consequently, 4,388 patients in each group were matched for analyses.

RESULTS

In propensity-matched patients, AAA was detected in 59 patients of the TTE group and in 48 patients of the AUS group; the prevalence of AAA detection did not differ significantly between TTE and AUS groups (P = 0.331). Positive associations were observed between AAA detection and male sex (adjusted odds ratio [OR]: 3.25; 95% confidence interval [CI], 2.05–5.15; P < 0.001), older age (adjusted OR: 1.029; 95% CI: 1.01–1.04; P < 0.001), and the presence of ischemic heart disease (adjusted OR: 1.78; 95% CI: 1.04–3.03; P = 0.033) and hypertension (adjusted OR: 2.16; 95% CI: 1.38–3.37; P = 001).

CONCLUSION

TTE detected AAA with comparable efficacy as AUS in propensity-matched groups who underwent scheduled TTE and AUS.

Integration of endovascular therapy of ruptured abdominal and iliac aneurysms in the treatment algorithm: a single-center experience in a medium-volume vascular center

PURPOSE

To evaluate the influence of endovascular therapy of ruptured abdominal or iliac aneurysms on total mortality.

MATERIALS AND METHODS

We analyzed the mortality of 40 patients from 2005 to 2009, when only surgical treatment was available. These results were compared with the period 2010 to 2013, when endovascular aneurysm repair (EVAR) was assessed as the first option in selected patients.

RESULTS

During 2005 to 2009, the mortality was 37.5%. From 2010 to 2013, 45 patients were treated with mortality 28.9%. Open repair was performed in 35 (77.8%) patients and EVAR in 10 (22.2%) patients. The 30-day and 1-year mortality rates of the EVAR group were 0% and 20%, respectively, and the total mortality rate was 30% during follow-up (median 11 months, range 1-42 months). The 30-day mortality in the surgical group remained unchanged, at 37.1%, and 1-year and total mortality rates were 45.7% and 51.4%, respectively.

CONCLUSION

Following integration in the treatment algorithm, EVAR decreased total mortality in our center by 8.6%.

Secondary modification into aortouniiliac configuration to salvage failed endovascular aneurysm repair is safe and effective but not associated with higher intervention rates during long-term follow-up

BACKGROUND

Reports of secondary modifications into aortouniiliac configuration to salvage-failed endovascular aneurysm repair (EVAR) are limited. We evaluated long-term results after these procedures and compared them with those after primary aortouniiliac endografting (AUE).

METHODS

A retrospective review of all EVAR performed from March 1995 until July 2011 was conducted. Patients were included when primary AUE (group I) or modification into aortouniiliac configuration (group II) was done.

RESULTS

Data analysis obtained 27 group I and 23 group II patients. Salvage of failed EVAR could be achieved in 96% of group II patients, and mortality was zero. Frequency of adverse events and amount of interventions to maintain aneurysm exclusion were not increased after secondary AUE. Kaplan-Meier estimates for long-term survival between groups were comparable (P = .36).

CONCLUSIONS

Secondary AUE allows correction of graft-related endoleaks potentially leading to late aneurysm rupture. Complications and adverse events throughout long-term follow-up were not necessarily increased when compared with primary AUE.

Open versus Endovascular Repair of Abdominal Aortic Aneurysm in the Elective and Emergent Setting in a Pooled Population of 37,781 Patients: A Systematic Review and Meta-Analysis

Background. We evaluated the incidence of mortality and myocardial infarction (MI) in endovascular repair (EVAR) as compared to open aneurysm repair (OAR) in both elective and ruptured abdominal aortic aneurysm (AAA ) setting. Methods. We analyzed the rates of 30-day mortality, 30-day MI, and hospital length of stay (LOS) based on comparative observation and randomized control trials involving EVAR and OAR. Results. 41 trials compared EVAR to OAR with a total pooled population of 37,781 patients. Analysis of elective and ruptured AAA repair favored EVAR with respect to 30-day mortality with a pooled odds ratio of 0.19 (95% CI 0.17–0.20; I² = 88.9%; P < 0.001). There were a total of 1,835 30-day MI events reported in the EVAR group as compared to 2,483 events in the OAR group. The pooled odds ratio for elective AAA was 0.74 (95% CI 0.58–0.96; P = 0.02) in favor of EVAR. The average LOS was reduced by 296.75 hrs (95% CI 156.68–436.82 hrs; P < 0.001) in the EVAR population. Conclusions. EVAR has lower rates of 30-day mortality, 30-day MI, and LOS in both elective and ruptured AAA repair.

[Epidemiology and risk factors for major respiratory complications after aortic surgery]

Introduction

L'incidence des complications respiratoires postopératoires (CRPO) reste très diversement appréciées selon les critères diagnostiques retenues dans les différentes études, ce qui la fait varier de 5 à plus de 50%. Les CRPO majeurs après chirurgie de l'aorte abdominale sont responsables d'une grande morbi-mortalité pouvant aller jusqu’à 36%, d'une durée d'hospitalisation et d'un coût plus importants. Ainsi dans l'optique d'améliorer notre prise en charge périopératoire de la chirurgie de l'aorte, nous avons décidé de mener une étude pour dresser le profil épidémiologique et déterminer les facteurs de risque des complications respiratoires dans notre contexte

Méthodes

Il s'agit d'une étude de cohorte rétrospective du mois de Janvier 2007 au mois de décembre 2011 portant sur l'ensemble des patients opérés pour pathologie aortique au bloc opératoire central de l'hôpital Ibn Sina de Rabat, Maroc.

Résultats

Cent vingt cinq patients ont été inclus dans notre étude, 24 patients ont été opérés pour anévrysme de l'aorte abdominale et 101 patients pour lésion occlusive aortoiliaque. Dans notre série 22 malades soit 17,6% ont présenté une complication respiratoire majeure avec, une reventilation dans 4,8% des cas, une difficulté de sevrage de la ventilation artificielle dans 3,2% des cas, une pneumopathie dans 4% des cas, un syndrome de détresse respiratoire aigue (SDRA) dans 4% des cas et une nécessité de fibroaspiration bronchique dans 1,6% des cas. En analyse univariée: l’âge, la présence d'une BPCO avec dyspnée stade 3 ou 4, la présence d'une anomalie à l'EFR préopératoire, la présence d'un stade avancé (III ou IV) de LOAI et la reprise chirurgicale étaient statistiquement associés à la survenue d'une complication respiratoire postopératoire. En analyse multivariée, seule une anomalie à l'EFR en préopératoire constituait un facteur de risque indépendant de survenue d'une complication respiratoire postopératoire dans notre série avec un Odds Ratio (OR): 11,5; un Intervalle de Confiance (IC) à 95% de (1,6 - 85,2) et un p = 0,016.

Conclusion

Au terme de notre étude, il nous parait donc nécessaire pour diminuer l'incidence des CRPO majeurs dans notre population, d'agir sur les facteurs que nous jugeons modifiables tel l'amélioration de l’état respiratoire basal moyennant une préparation respiratoire préopératoire, s'intégrant dans un véritable programme de réhabilitation et associant une rééducation à l'effort, une kinésithérapie incitative ainsi qu'une optimisation des thérapeutiques habituelles.

Duplex ultrasound evaluation of endoluminally treated aortic aneurysms with emphasis on diameter measurement: A comparison with computed tomography

PURPOSE

The aim of this study was to determine the accuracy of color Doppler ultrasound (CDUS) for endoleak detection and measurement of the aneurysm diameter after endovascular aortic aneurysm repair.

METHODS

Forty-eight CDUS and computed tomographic angiography (CTA) examinations performed concurrently on 29 patients who were treated with endovascular stent grafts for abdominal aortic aneurysms were included in the study. CTA and CDUS findings were retrospectively compared for aneurysm diameter, patency of the graft, and the presence of leaks in the aneurysm's lumen (the so-called "endoleaks").

RESULTS

The stent graft was patent in all patients. Including the follow-up examinations, endoleaks were detected in a total of 17 CTA studies. The sensitivity, specificity, and positive and negative predictive values for CDUS compared with CTA as the gold standard were 100%, 96%, 94.4%, and 100%, respectively. Kappa statistics showed a high level of agreement between CDUS ant CTA examinations (χ = 0.95). The aneurysm diameters measured with CDUS and CTA were significantly different, but within 5 mm of each other in 83% of patients.

CONCLUSIONS

Provided that a strict CDUS protocol including spectral analysis of perigraft flow is used, CDUS is comparable to CTA for endoleak detection and measurement of the aneurysm diameter.

Complete ten-year follow-up after endovascular abdominal aortic aneurysm repair: survival and causes of death

PURPOSE

To analyze the hazard and causes of death after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms during a complete ten year follow-up.

METHODS

This is a retrospective clinical study of 130 consecutive patients undergoing EVAR between 1995 and 1998. One-hundred twenty-one patients (93.1%) were treated with first-generation stentgrafts and nine patients (6.9%) received second-generation devices. All patients completed a follow-up of at least 10 years, unless death occurred before then. Time and causes of death were provided by the Austrian central register of deaths.

RESULTS

The median follow-up was 7.6 years, and the 130 patients had 968.5 person-years of follow-up. The ten-year mortality rate was 62.3%. Cardiovascular events were the most frequent causes of death, with a 3.9 incidence rate per 100 person-years. Cancer death and death due to other causes occurred in 2.1 and 1.8 cases per 100 person-years, respectively. Lethal late aneurysm rupture happened in 4.6% (n=6), which corresponds to an annual incidence rate of 0.6 per 100 person-years. All of those patients had been treated with first-generation devices.

CONCLUSIONS

Cardiovascular events were the most frequent cause of death after EVAR, followed by malignancy and other diseases. The risk of dying from secondary rupture was clearly lower than that of death due to other reasons during ten years after EVAR, even in patients with first-generation stentgrafts.

Outcome and quality of life after aorto-bifemoral bypass surgery

BACKGROUND

Aorto-bifemoral bypass (AFB) is commonly performed to treat aorto-iliac disease and a durable long-term outcome is achieved. Most studies documenting beneficial outcomes after AFB have been limited to mortality and morbidity rates, costs and length of hospital stay (LOS). Few studies have examined the dependency of patients and how their perception of their own health changes after surgery. The aim of the present study was to evaluate outcome after AFB and to study its determinants.

METHODS

This retrospective study was carried out in the multidisciplinary Post-Anaesthesia Care Unit (PACU) with five intensive care beds. Out of 1597 intensive care patients admitted to the PACU, 75 were submitted to infrarenal AFB and admitted to these intensive care unit (ICU) beds over 2 years. Preoperative characteristics and outcome were evaluated by comparing occlusive disease with aneurysmatic disease patients. Six months after discharge, the patients were contacted to complete a Short Form-36 questionnaire (SF-36) and to have their dependency in Activities of Daily Living (ADL) evaluated. Patient's characteristics and postoperative follow-up data were compared using Mann-Whitney U test, t test for independent groups, chi-square or Fisher's exact test. Patient preoperative characteristics were evaluated for associations with mortality using a multiple logistic regression analysis.

RESULTS

The mortality rate was 12% at six months. Multivariate analysis identified congestive heart disease and APACHE II as independent determinants for mortality. Patients submitted to AFB for occlusive disease had worse SF-36 scores in role physical and general health perception. Patients submitted to AFB had worse SF-36 scores for all domains than a comparable urban population and had similar scores to other PACU patients. Sixty-six percent and 23% of patients were dependent in at least one activity in instrumental and personal ADL, respectively, but 64% reported having better general health.

CONCLUSION

This study shows that congestive heart disease and APACHE II were risk factors for mortality after AFB surgery. Survivors who have undergone AFB perceive an improved quality of life although they are more dependent in ADL tasks and have worse scores in almost all SF-36 than the population to which they belong.

Postimplantation syndrome in a kidney trasplant patient: fever is not always synonimous with infection

Fever in an immunocompromised patient like the transplanted subject is usually due to an overt or occult infection. Clinicians must make important decisions to find the cause of fever, and also concerning the timing and adequacy of empiric antibiotic therapy. However, occasionally, fever is not due to an infectious cause. A correct identification of its causes may avoid a needlessly prolonged course of antibiotics. Herein we have reported a kidney transplant patient with a febrile syndrome, which appeared after endovascular aortoiliac stent-graft placement, that was finally attributed to a noninfectious cause like postimplantation syndrome.

Effects of study design and trends for EVAR versus OSR

Purpose:

To investigate if study design factors such as randomization, multi-center versus single center evidence, institutional surgical volume, and patient selection affect the outcomes for endovascular repair (EVAR) versus open surgical repair (OSR). Finally, we investigate trends over time in EVAR versus OSR outcomes.

Methods:

Search strategies for comparative studies were performed individually for: OVID’s MEDLINE, EMBASE, CINAHL, HAPI, and Evidence Based Medicine (EBM) Reviews (including Cochrane DSR, ACP Journal Club, DARE and CCTR), limited to 1990 and November 2006.

Results:

Identified literature: 84 comparative studies pertaining to 57,645 patients. These include 4 randomized controlled trials (RCTs), plus 2 RCTs with long-term follow-up. The other 78 comparative studies were nonrandomized with 75 reporting perioperative outcomes, of which 16 were multi-center, and 59 single-center studies. Of the single-center studies 31 were low-volume and 28 were high-volume centers. In addition, 5 studies had all patients anatomically eligible for EVAR, and 8 studies included high-risk patients only. Finally, 25 long term observational studies reported outcomes up to 3 years.

Outcomes:

Lower perioperative mortality and rates of complications for EVAR versus OSR varied across study designs and patient populations. EVAR adverse outcomes have decreased in recent times.

Conclusion:

EVAR highlights the problem of performing meta-analysis when the experience evolves over time.

Long-Term Survival in Men With High Grade Prostate Cancer: A Comparison Between Conservative Treatment, Radiation Therapy and Radical Prostatectomy—A Propensity Scoring Approach

PURPOSE

We performed a retrospective cohort study using propensity score analysis to calculate long-term survival in patients with prostate cancer with Gleason score 8 or greater who were treated with conservative therapy, radiation therapy and radical prostatectomy.

MATERIALS AND METHODS

Between January 1, 1980 and December 31, 1997, 3,159 patients in the Henry Ford Health System were diagnosed with clinically localized prostate cancer. Of these patients 453 had a Gleason score of 8 or greater in the biopsy specimen and they were the cohort. The end points were overall and prostate cancer specific survival. Propensity score analysis was used to more precisely compare the 3 treatments of observation, radiation and radical prostatectomy. Median patient followup was longer in the radical prostatectomy arm than in the conservative treatment and radiation therapy arms (68 months vs 52 and 54, respectively).

RESULTS

Of the 453 patients 197 (44%) were treated conservatively, 137 (30%) received radiation therapy and 119 (26%) underwent radical prostatectomy. Using propensity scoring analysis median overall survival for conservative therapy, radiation and radical prostatectomy was 5.2, 6.7 and 9.7 years, respectively. Median cancer specific survival was 7.8 years for conservative therapy and more than 14 years for radiation therapy and radical prostatectomy. The risk of cancer specific death following radical prostatectomy was 68% lower than for conservative treatment and 49% lower than for radiation therapy (p<0.001 and 0.053, respectively).

CONCLUSIONS

Survival of men with high grade prostate cancer can be improved by radical prostatectomy or radiation therapy.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Polymethylmethacrylate (PMMA) as an embedding medium preserving tissues and foreign materials encroaching in endovascular devices

Problems of displacement, poor healing, degradation of the polymers and corrosion of the metallic frame in endovascular devices still require in-depth investigations. As the tissues and the foreign materials are in close contact, it is of paramount importance to efficiently investigate the interfaces between them. Inclusion in polymethymethacrylate (PMMA) permits us to obtain thin slides and preserve the capacity to perform the appropriate stainings. An AneuRx prosthesis was harvested in bloc with the surrounding tissues at the autopsy of a patient 25 months post deployment in a 5.7 cm diameter AAA and sectioned in the direction of the blood flow in two halves. A cross-section of the encapsulated distal segment together with the surrounding aneuryshmal sac was embedded in polymethylmethacrylate (PMMA). Further to complete polymerization, slices of the specimen were cut on a precision banding saw under coolant. They were affixed onto methacrylate slides with a UV cured adhesive. Binding and polishing were done on a numeric grinder and slices 25 to 30 microm in thickness were stained with toluidine blue prior to observation in light microscopy. Additional slices were prepared for scanning electron microscopy and X-ray energy dispersive spectrometry for determination of the elemental composition of the Nitinol stent. The aortic wall did not demonstrate complete integrity along with its circumference. Some areas of rupture were noted. The content of the sac was heavily shrunk and was mostly acellular. The walls of the device were very well encapsulated. The PMMA embedding permitted the polyester wall, the Nitinol wire and the collagen to keep in close contact. Scanning electron microscopy involved backscattered electrons and confirmed the corrosion the Nitinol wire at the boundary with living tissues. Based upon the results obtained, we believe that PMMA embedding is the most appropriate method to process endovascular devices for histological and material investigation. Needless to say, that paraffin embedding would have not been feasible for such a big size specimen involving different materials.

A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

OBJECTIVE

Propensity score (PS) analyses attempt to control for confounding in nonexperimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling.

STUDY DESIGN AND METHODS

Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003.

RESULTS

Use of propensity scores increased from a total of 8 reports before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented.

CONCLUSIONS

Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods.

MRI versus helical CT for endoleak detection after endovascular aneurysm repair

OBJECTIVE

The objective of our study was to investigate the diagnostic accuracy of MRI and helical CT for endoleak detection.

SUBJECTS AND METHODS

Fifty-two patients underwent endovascular aneurysm repair with nitinol stent-grafts. Follow-up data sets included contrast-enhanced biphasic CT and MRI within 48 hr after the intervention; at 3, 6, and 12 months; and yearly thereafter. The endoleak size was categorized as < or = 3%, > 3% < or = 10%, > 10% < or = 30%, or > 30% of the maximum cross-sectional aneurysm area. A consensus interpretation of CT and MRI was defined as the standard of reference.

RESULTS

Of 252 data sets, 141 showed evidence for endoleaks. The incidence of types I, II, and III endoleaks and complex endoleaks was 3.2%, 40.1%, 8.7%, and 4.0%, respectively. The sensitivity for endoleak detection was 92.9%, 44.0%, 34.8%, and 38.3% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively. The corresponding negative predictive values were 91.7%, 58.4%, 54.7%, and 56.1%, respectively. The overall accuracy of endoleak detection and correct sizing was 95.2%, 58.3%, 55.6%, and 57.1% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively.

CONCLUSION

MRI is significantly superior to biphasic CT for endoleak detection and rating of endoleak size, followed by uniphasic late and uniphasic arterial CT scans. MRI shows a significant number of endoleaks in cases with negative CT findings and may help illuminate the phenomenon of endotension. Endoleak rates reported after endovascular aneurysm repair substantially depend on the imaging techniques used.

Anesthésie et réanimation pour chirurgie réglée de l'anévrisme de l'aorte abdominale

OBJECTIVES

Patient scheduled for infrarenal abdominal aortic aneurysm surgery carries a high risk of cardiac or respiratory comorbidity. To outline the perioperative management for these patients.

METHODS

Review of the literature using MesH Terms "abdominal aortic aneurysm", "anesthesia", "analgesia" "critical care" and/or "surgery" in Medline database.

RESULTS

Cardiac preoperative evaluation and management have recently been reviewed. Intermediate and high-risk patients should undergo non-invasive cardiac testing to decide between a preoperative medical strategy (using betablocker+/-statin and aspirin) and an interventional strategy (coronary angioplasty or cardiac surgery). Perioperative myocardial ischaemia should also be investigated by clinical, electrocardiographic and biologic monitoring such as plasmatic troponin Ic dosage. Specific score could also assess the respiratory failure risk preoperatively. Epidural analgesia decreases this risk. There is no evidence that a pharmacological treatment decreases the incidence of acute renal failure after aortic surgery. Endovascular repair is actually recommended for older, higher-risk patients or patients with a hostile abdomen or other technical factors that may complicate standard open repair.

Pain and Quality of Life Assessment after Endovascular Versus Open Repair of Abdominal Aortic Aneurysms in Patients at Low Risk

PURPOSE

To compare functional autonomy, quality of life (QOL), and pain control after endovascular and open repair (OR) of abdominal aortic aneurysms.

MATERIALS AND METHODS

Forty patients with a low surgical risk profile and anatomic compatibility for stent-graft therapy were randomized to receive OR or endovascular aneurysm repair (EVAR). Technical and clinical success as well as mortality were assessed in both groups and compared by Kaplan-Meier analysis. Functional autonomy and QOL were assessed by Karnofsky score and Short Form 36 (SF-36) questionnaire. Pain control was assessed by a numeric rating scale and Brief Pain Inventory questionnaire. QOL outcomes by means of the SF-36 and pain questionnaires were compared with use of mixed-effects models for repeated-measures analysis.

RESULTS

All procedures were technically successful in both groups. Three late clinical failures requiring surgical conversion or repeated intervention were observed in the EVAR group and one was observed in the OR group. There was no significant difference between groups in terms of functional autonomy or QOL. No difference in pain level was evident during the early postoperative period, whereas the pain level was lower in the OR group after 1 month. Opioid analgesic drug consumption was significantly greater in the OR group during the postoperative period. Mean hospitalization duration was shorter in the EVAR group than in the OR group (4.5 days +/- 2.4 vs 11.5 days +/- 8.1; P= .001).

CONCLUSION

EVAR has no advantage over OR in patients at low risk in terms of functional autonomy, QOL, and pain control. However, EVAR was associated with shorter hospitalization durations compared with OR.

Treatment possibility for AAA of the visceral branches region

The authors describe a promising abdominal aortic aneurysm treatment--a combined endovascular/surgical approach--used in two cases of aneurysm taking the aortic visceral branches region.

Endografting Increases Total Volume of AAA Repairs but Not at the Expense of Open Surgery: Experience in More Than 1000 Patients

PURPOSE

To compare the volume of open graft replacements (OGR) for abdominal aortic aneurysm (AAA) versus endovascular aneurysm repairs (EVAR) over time and after modifying selection criteria.

METHODS

A review was conducted of 1021 consecutive patients who underwent AAA repair from 1989 through 2002: 496 elective OGRs for infrarenal AAAs (STANDARD), 289 elective EVARs for infrarenal AAAs, 59 complex OGRs for suprarenal AAAs, and 177 emergent OGRs for ruptured AAAs. Patients from 1995 to 2002 were divided into 2 groups based on shifting treatment strategies; 454 patients were treated by STANDARD or EVAR at the surgeon's discretion between 1995 and 2000 (post EVAR). The second group comprised 161 patients treated in 2001-2002 after the introduction of "high-risk" screening criteria (age > or = 72 years, diabetes mellitus, renal dysfunction, impaired pulmonary function, or ASA class IV) that dictated EVAR whenever anatomically feasible. For comparison, 170 STANDARD repairs performed in the 6 years prior to EVAR served as a control.

RESULTS

While surgery for ruptured AAAs remained fairly stable over the 14-year period, the number of patients undergoing elective repair increased due to the implementation of EVAR. During the 6 years after its introduction, EVAR averaged 34.3 patients per year; after 2001, the annual frequency of EVAR increased to 41.5 (p > 0.05). In like fashion, the rate of STANDARD repairs increased to 41.3 patients per year versus 28.3 before EVAR (p = 0.032). ASA class IV patients increased by almost 9 fold in the recent period versus pre EVAR (p = 0.006). The overall mortality after elective infrarenal AAA repair decreased between the pre and post EVAR periods (6.5% versus 3.7%, p > 0.05) and fell still further to 1.2% in the most recent period (p = 0.021 versus pre EVAR).

CONCLUSIONS

The implementation of an EVAR program increases the total volume of AAA repairs but does not reduce open surgical procedures. By allocating patients to EVAR or open repair based their risk factors, mortality was markedly reduced.

Propensity score methods gave similar results to traditional regression modeling in observational studies: a systematic review

OBJECTIVE

To determine whether adjusting for confounder bias in observational studies using propensity scores gives different results than using traditional regression modeling.

METHODS

Medline and Embase were used to identify studies that described at least one association between an exposure and an outcome using both traditional regression and propensity score methods to control for confounding. From 43 studies, 78 exposure-outcome associations were found. Measures of the quality of propensity score implementation were determined. The statistical significance of each association using both analytical methods was compared. The odds or hazard ratios derived using both methods were compared quantitatively.

RESULTS

Statistical significance differed between regression and propensity score methods for only 8 of the associations (10%), kappa = 0.79 (95% CI = 0.65-0.92). In all cases, the regression method gave a statistically significant association not observed with the propensity score method. The odds or hazard ratio derived using propensity scores was, on average, 6.4% closer to unity than that derived using traditional regression.

CONCLUSIONS

Observational studies had similar results whether using traditional regression or propensity scores to adjust for confounding. Propensity scores gave slightly weaker associations; however, many of the reviewed studies did not implement propensity scores well.

AAA elective treatment indication tactics in EVAR era

The authors describe their indication tactics for AAA elective treatment. Based on one-month morbidity and mortality they evaluate the results obtained in the past six years and compare the methods of open surgery, endovascular repair and combined strategy in AAAs elective repair.

Endovascular treatment of abdominal aortic aneurysms--6 years of experience with Ella stent-graft system

PURPOSE

Evaluation of 6-year results of abdominal aortic aneurysm (AAA) treatment by Ella stent-grafts with regard to safety and effectivity in relation to morphology of the aneurysm.

METHODS

From a group of 172 patients with AAA, in whom elective endovascular treatment was considered, 120 of them (69.8%) were found to be suitable for this type of therapy. The bifurcated type of stent-graft was implanted in 97 patients, uniiliacal type in 19 patients and only four patients were found to be suitable for tubular type of stent-graft. Additional necessary procedures (internal iliac artery occlusion or contralateral common iliac artery occlusion in a group of patients with uniiliacal type of stent-graft) were performed surgically during the stent-graft implantation. CT and US controls were performed at 3, 6 and 12 months after implantation, later every 12 months.

RESULTS

Primary technical success was achieved in 109 of the 120 patients (91%). Primary endoleak was recorded in 11 patients (primary endoleak type Ia in seven patients, type Ib in three patients and type IIIa in one patient). Assisted technical success after reintervention or spontaneous seal was 98.3%. Surgical conversion was indicated in two patients (1.7%). Perioperative mortality rate was 3.3%. Total average follow-up period was 20.7 months (range from 2 to 60 months). In nine patients (7.5%) secondary endoleak type II was found at control CT or US, in three patients partial thrombosis of the stent-graft was found. There was no aneurysm rupture during follow-up.

CONCLUSION

Treatment of AAA with Ella stent-graft system is effective and safe. Bifurcated stent-graft is the most frequently used type. Uniiliacal type of stent-graft is used by us only in cases of complicated morphology.