Abdominal aortic aneurysms: elective endovascular repair versus conventional surgery--evaluation with evidence-based medicine techniques

Prophylactic absorbable gelatin sponge embolization for angiographically occult splenic hemorrhage

Nonoperative management of traumatic splenic hemorrhage includes the targeted administration of embolic agents. In certain instances where computed tomography angiography cannot exclude a bleed, prophylactic embolization with absorbable gelatin sponge has been used. In this retrospective case series review, we characterized the demographic data and clinical outcomes associated with 4 patients who underwent prophylactic transarterial splenic artery embolization after blunt abdominal trauma. Embolization was employed in cases where computed tomography angiography findings suggested at least a moderate splenic injury, and simultaneously where hemorrhage was not apparent during fluoroscopic angiography. Periprocedural hemodynamic status, technical success, and postoperative complications are discussed. The goal of this report was to discuss the safety and efficacy of prophylactic gelatin sponge embolization for occult splenic hemorrhage. In cases where a hemorrhagic site might be occult, this approach has the potential to minimize bleeding complications and the need for further intervention.

Evidence levels for neuroradiology articles: low agreement among raters

BACKGROUND AND PURPOSE

Because evidence-based articles are difficult to recognize among the large volume of publications available, some journals have adopted evidence-based medicine criteria to classify their articles. Our purpose was to determine whether an evidence-based medicine classification used by a subspecialty-imaging journal allowed consistent categorization of levels of evidence among different raters.

MATERIALS AND METHODS

One hundred consecutive articles in the American Journal of Neuroradiology were classified as to their level of evidence by the 2 original manuscript reviewers, and their interobserver agreement was calculated. After publication, abstracts and titles were reprinted and independently ranked by 3 different radiologists at 2 different time points. Interobserver and intraobserver agreement was calculated for these radiologists.

RESULTS

The interobserver agreement between the original manuscript reviewers was -0.2283 (standard error = 0.0000; 95% CI, -0.2283 to -0.2283); among the 3 postpublication reviewers for the first evaluation, it was 0.1899 (standard error = 0.0383; 95% CI, 0.1149-0.2649); and for the second evaluation, performed 3 months later, it was 0.1145 (standard error = 0.0350; 95% CI, 0.0460-0.1831). The intraobserver agreement was 0.2344 (standard error = 0.0660; 95% CI, 0.1050-0.3639), 0.3826 (standard error = 0.0738; 95% CI, 0.2379-0.5272), and 0.6611 (standard error = 0.0656; 95% CI, 0.5325-0.7898) for the 3 postpublication evaluators, respectively. These results show no-to-fair interreviewer agreement and a tendency to slight intrareviewer agreement.

CONCLUSIONS

Inconsistent use of evidence-based criteria by different raters limits their utility when attempting to classify neuroradiology-related articles.

Preprocedural planning for endovascular stent-graft placement

Endovascular stent grafts have become a viable treatment for aortic thoracic and abdominal aneurysms in both elective and emergent situations. Computed tomographic (CT) angiography is the primary tool for determining eligibility for this procedure. This article discuses the preprocedural evaluation of an endovascular stent candidate. Evaluation begins with identification of the aneurysm pathology and its relationship to treatment efficacy. The radiologist must evaluate the aneurysm geometry for compatibility with stent hardware. Aneurysm features that suggest a contraindication must be recognized. Procedures that involve a combination of endovascular stenting and surgical revascularization are discussed so that the reader understands the limits of stent eligibility. Vascular access for stent placement must also be evaluated for the ability to accommodate stent delivery. The radiologist also must be familiar with CT imaging protocols and alternative methods of imaging that can evaluate stent feasibility. The utility of three-dimensional processing is discussed.

Cost and effectiveness comparison of endovascular aneurysm repair versus open surgical repair of abdominal aortic aneurysm: a single-center experience

The study objective was to compare the cost and effectiveness of two surgical techniques: open repair and endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA). We assessed 58 surgical operations of AAA repair conducted in 54 men and 4 women (aged 49-94 years) during 2003 and 2004. Open surgical repair was performed in 21 patients, and EVAR was performed in 37 patients. The evaluation of the effectiveness of both methods was based on the following factors: mortality within 30 days, surgery duration, total hospitalization time, and intensive care unit stay duration. The segmental costs of grafts, anesthesia, and extra materials were included in the calculations for the comparison of the costs of the two methods. A 30-day mortality of 5.17% and 0% was demonstrated for open surgical repair and EVAR, respectively. In regard to the operation's mean duration, this was calculated to 279.52 minutes for open repair and 193.57 minutes for EVAR. The mean duration of the in-hospital stay was 11.3 and 4.09 days for open repair and EVAR, respectively. Accordingly, the mean duration of intensive care unit stay was 2.81 and 0.23 days, respectively. The cost evaluation revealed a mean cost of 5374.3euro ($7,643.49) and 20,592.52euro ($29,287.50) for open repair and EVAR, respectively. Open repair is a "tested method" of its own time. EVAR seems to have the advantage on aspects of effectiveness, yet its major hallmark is its significant cost, as indicated in the relevant part of the current study.

Which patients will benefit from percutaneous radiofrequency ablation of colorectal liver metastases? Critically appraised topic

In clinical radiology, there are numerous examples of new techniques that were initially enthusiastically promoted and then subsequently abandoned when early promise was not realized in routine patient care. Appropriateness of new or established interventional radiology techniques to specific clinical conditions must be determined from clinical experience, from communication with experts in the field and/or careful review of available medical literature, and on an individual patient basis by means of review of clinical notes and diagnostic imaging studies. For patients with liver neoplasms, regional techniques such as radiofrequency ablation (RFA) have been developed and are now the subject of ongoing research. This article describes the utilization of Evidence-Based Practice (EBP) techniques as a means of deciding the appropriateness of percutaneous RFA in treating colorectal liver metastases (CLM).

Evidence-based practice in radiology education: why and how should we teach it?

Evidence-based practice in radiology (EBR) is becoming firmly established as a method to enhance the knowledge and fill the need for further knowledge within the profession. It has been identified as an essential part of the training program, both at medical school and at the resident and/or fellowship level. This review aims to describe the essential components of EBR, to describe the educational theories that may be applied to developing EBR within the curriculum, and to give several models that have been shown to result in greater student and resident participation in the search and exploration of evidence-based practice.

Sealing of type III endoleaks with ethylene vinyl alcohol copolymer in a canine model

PURPOSE

To test ethylene vinyl alcohol copolymer (EVOH) as a sealing agent for persistent abdominal aortic aneurysm (AAA) endograft leaks.

MATERIALS AND METHODS

Twelve dogs underwent creation of AAAs with a Palmaz P4014 stent. A 10-mm x 5-cm Wallgraft endoprosthesis with a 4-mm-diameter hole cut into its side was deployed within the AAA. One week later, computed tomography (CT) and angiography were performed and the aneurysm sac was catheterized through the 4-mm hole. Then, EVOH was injected into the sac and lumbar arteries. Four weeks thereafter, all surviving animals underwent repeat CT scanning and angiography and were then euthanized. The AAA underwent gross and microscopic study.

RESULTS

Three dogs died from aortic rupture within 24 hours of AAA creation and the remaining nine dogs survived to receive EVOH. All nine dogs had persistent flow into the sac and lumbar arteries at the time of EVOH delivery. Seven dogs survived to the end of the experiment, and all aneurysm sacs and lumbar arteries remained occluded on angiography and CT. Histologic examination revealed EVOH and thrombus admixed, with thrombus in varying stages of organization filling the aneurysm sac and lumbar arteries.

CONCLUSIONS

Embolization of type III endoleaks with EVOH proved to be feasible in a canine model. Further work is warranted to determine its therapeutic utility.

FDG PET in preoperative assessment of colorectal liver metastases combining "evidence-based practice" and "technology assessment" methods to develop departmental imaging protocols: should FDG PET be routinely used in the preoperative assessment of patients with colorectal liver metastases?

In today's environment of progressively evolving and expensive imaging modalities, radiologists are asked to justify the use of resources to patients, referring physicians, hospital management, and third party payers. With this aim, the radiologist may use "top-down" or "bottom-up" "evidence-based practice" (EBP) techniques. "Top-down" suggests that the practitioner should wait until a higher authority, external to their practice, generates a solution to practice dilemmas (e.g., National Institute for Health and Clinical Excellence [NICE] guidelines). "Bottom-up" however, is based on the theory that the ordinary practitioner is best served by a decentralized approach to problem solving that is internal to their practice. The technology assessment framework modeled by Mackenzie and Dixon comprehensively assesses the effects of imaging using levels of efficacy including diagnostic performance, diagnostic impact, and therapeutic impact, impact on health and cost effectiveness. In this article, we describe how issues regarding new imaging modalities in ordinary radiology practice can be addressed by using stepwise "bottom-up" EBP techniques combined with the technology assessment framework. We also detail how EBP techniques form an integral part of practice-based learning among radiology residents as part of noninterpretive residency training. The following clinical scenario is used: your hospital's chief hepatobiliary surgeon writes to your department regarding the lack of access to 18-fluoro-2-deoxy-D-glucose positron emission tomography in the preoperative assessment of patients with colorectal cancer liver metastases under consideration for hepatic resection. How would you approach this problem? Here is how we would do it.

Cost-effectiveness of abdominal aortic aneurysm repair: A systematic review

Objectives: A systematic review of the cost-effectiveness of abdominal aortic aneurysm (AAA) repair was conducted. Although open surgery has been considered the gold standard for prevention of AAA rupture, emerging less-invasive endovascular treatments have led to increased interest in evaluating the cost and cost-effectiveness of treatment options.

Methods: A systematic review of studies published in MEDLINE between 1999 and 2005 reporting the cost and/or cost-effectiveness of endovascular and/or open surgical repair of nonruptured AAAs was conducted. Case series studies with less than fifty patients per treatment were excluded.

Results: Of twenty eligible articles, three were randomized controlled trials, twelve case series, four Markov models, and one systematic review. Regardless of time frame, all studies found that endovascular repair costs more than open surgery. Although the high cost of the endovascular prosthesis was partially offset by reduced intensive care, hospital length of stay, operating time, blood transfusions, and perioperative complications, hospital costs were still greater for endovascular than open surgical repair. For patients medically fit for open surgery, mid-term costs were greater for endovascular repair with no difference in overall survival or quality of life. For patients medically unfit for open surgery, endovascular repair costs more than no intervention with no difference in survival.

Conclusions: Although conclusions regarding the cost-effectiveness of AAA treatment options are time dependent and vary by institutional perspective, from a societal perspective, endovascular repair is not currently cost-effective for patients with large AAA regardless of medical fitness.

Spectrum of CT Findings in Rupture and Impending Rupture of Abdominal Aortic Aneurysms

Prompt diagnosis of rupture and impending rupture of abdominal aortic aneurysms is imperative. The computed tomographic (CT) findings of ruptured abdominal aortic aneurysms are often straightforward. Most ruptures are manifested as a retroperitoneal hematoma accompanied by an abdominal aortic aneurysm. Periaortic blood may extend into the perirenal space, the pararenal space, or both. Intraperitoneal extravasation may be an immediate or a delayed finding. Discontinuity of the aortic wall or a focal gap in otherwise continuous circumferential wall calcifications may point to the location of a rupture. There usually is a delay of several hours between the initial intramural hemorrhage and frank extravasation into the periaortic soft tissues. Contained or impending ruptures are more difficult to identify. A small amount of periaortic blood may be confused with the duodenum, perianeurysmal fibrosis, or adenopathy. Imaging features suggestive of instability or impending rupture include increased aneurysm size, a low thrombus-to-lumen ratio, and hemorrhage into a mural thrombus. A peripheral crescent-shaped area of hyperattenuation within an abdominal aortic aneurysm represents an acute intramural hemorrhage and is another CT sign of impending rupture. Draping of the posterior aspect of an aneurysmal aorta over the vertebrae is associated with a contained rupture.

Evidence-based Practice in Radiology: Steps 3 and 4—Appraise and Apply Interventional Radiology Literature

When introducing new interventional radiology techniques or devices, it is important to learn from previous experiences and to remember that there are numerous examples of new techniques that were initially enthusiastically promoted and then subsequently abandoned when early promise was not realized. Appropriateness of new or established interventional radiology techniques to specific clinical conditions must be determined from clinical experience, from communication with experts in the field and/or careful review of available medical literature, and on an individual patient basis by means of review of clinical notes and diagnostic imaging studies. Several paradigms for evidence-based practice (EBP) exist. One model proposes that a central specialized process involving academic centers should primarily construct valid guidelines to direct practice at all levels of medical practice ("top-down" model). An alternative model integrates "the best research evidence with clinical expertise and patient values" ("bottom-up" model). This article will focus on the bottom-up model and describe the use of EBP by individual practitioners or groups of practitioners in optimizing literature review and critical appraisal. EBP is applied to two scenarios as a means of deciding the appropriateness of introducing interventional radiology techniques in a community hospital setting. The authors will also briefly discuss other applications for EBP techniques in interventional radiology, including development of practice guidelines or policy to ensure appropriate and safe practices.

Evidence-based radiology: steps 1 and 2--asking answerable questions and searching for evidence

Evidence-based medicine originated at McMaster University, Hamilton, Ontario, Canada, where it was defined as "the integration of current best evidence with clinical expertise and patient values" by the Evidence-based Medicine Working Group led by Drs Gordon Guyatt and David Sackett. From this developed the McMaster University and National Health Service Centre for Evidence-Based Medicine, University of Oxford, paradigm of evidence-based practice, which consists of five steps that can be used by ordinary practitioners: formulate answerable questions with which to search for evidence, search the literature, appraise the retrieved evidence by using explicit methods, apply results to a patient or patient group, and evaluate one's evidence-based practice and clinical performance and practice. This communication is about the first two steps of this process. Step 1 provides a framework for more effective question formulation that improves subsequent literature searches. It works equally well for questions about diagnostic and interventional radiology. A clinical scenario for a diagnostic question is used to illustrate the formulation of an answerable question. This question is then used to illustrate step 2-how and where to search for evidence.

Evidence-based Practice in Radiology: Steps 3 and 4—Appraise and Apply Diagnostic Radiology Literature

Several paradigms for evidence-based practice (EBP) exist. One model proposes that specialist academic centers should primarily construct valid guidelines for various topics in medicine (top-down model). An alternative model integrates "the best research evidence with clinical expertise and patient values" (bottom-up model). Whereas the former model inherently implies a central specialized process, the latter implies that practitioners working in nonspecialist centers can learn and implement a standardized set of tools with which to ask a question, search and appraise the literature, and then apply best current evidence in a local setting. This article focuses on appraising the literature and applying retrieved results and is part of a series on EBP in radiology. This article describes a clinical scenario in which a new respirologist at a hospital requests indirect computed tomographic (CT) venography as part of a work-up of a patient with a high pretest probability for pulmonary embolism and a positive d-dimer test result. Many controversies surround the technique of indirect CT venography, and difficult topics such as this are ideally suited to the tools of EBP. This article will describe how to approach such a scenario.

Current Status of Endovascular Repair of Infrarenal Abdominal Aortic Aneurysms in the Context of 50 Years of Conventional Repair

The operative risk for conventional open repair of nonruptured infrarenal abdominal aortic aneurysms (AAAs) has steadily declined during the past several decades to the point that open procedures now can be done with a mortality rate of approximately 2% at tertiary referral centers. Nevertheless, population-based studies suggest that the mortality rate for open AAA repair remains nearly 7% in many communities, a finding that undoubtedly is influenced by a substantial risk for unfavorable outcomes in patients who represent less than ideal candidates for major abdominal operations on the basis of advanced age and the medical comorbidities that so often accompany it. Endovascular aneurysm repair (EVAR) is a landmark contribution to the management of such patients and has been associated with significant overall reductions in the operative mortality rate in statewide and national audits. This early advantage of EVAR comes at the price of a unique set of complications, secondary interventions, and related expenses, however, and randomized clinical trials of EVAR versus open repair have not yet demonstrated differences in survival or quality of life within 4 years of follow-up. Data from the Nationwide Inpatient Sample and other sources indicate that the mortality rate for open AAA repair appears to be less than 2% in patients who are 65 years of age or younger. This low operative risk may not justify exposure to whatever incidence of late complications the current generation of endografts may prove to have during the relatively long survival times that can be anticipated for these patients.

Stent-Grafts for Unruptured Abdominal Aortic Aneurysms: Current Status

Aortic stent-grafts were introduced at the beginning of the 1990s as a less invasive method of dealing with aortic aneurysms in patients with poor cardiovascular reserve. The numbers of procedures performed worldwide has increased exponentially despite the current lack of any substantial evidence for long-term efficacy in comparison with the gold standard of open surgical grafting. This review summarizes the evolution of the abdominal aortic stent-graft, the techniques used for assessment and deployment, and the effect of the procedure on both the patient and the device. The recent publication of two national multicenter trials has confirmed that the endovascular technique confers a 2.5-fold reduction in 30-day mortality in comparison with open surgery. However, over 4 years of follow-up, there is a 3-fold increase in the risk of reintervention and the overall costs are 30% greater with endovascular repair. Although the improvement in aneurysm-related mortality persists in the mid-term, because of the initial reduction in perioperative mortality, the all-cause mortality rate at 4 years is actually no better than for open surgery. Longer-term data from the randomized trials are awaited as well as results from the latest trials utilizing state-of-the-art devices. Whilst the overall management of abdominal aortic aneurysms has undoubtedly benefited from the introduction of stent-grafts, open repair currently remains the gold standard treatment.

Abdominal aortic aneurysm (AAA): cost-effectiveness of screening, surveillance of intermediate-sized AAA, and management of symptomatic AAA

Physicians must make decisions about screening patients for abdominal aortic aneurysms (AAAs), monitoring or referring for surgery patients with AAAs of various sizes, and assessing patients with symptoms that may be related to AAAs. This review article analyzes the evidence for each scenario. The effectiveness and cost-effectiveness of screening for AAA is based on results from four randomized controlled trials. A cost-effectiveness analysis using a Markov model showed that ultrasound screening of white men beginning at age 65 is both effective and cost-effective in preventing AAA-related death. Such screening would have a small but real impact over a 20-year period in these men. For patients with a known AAA-which is often detected incidentally-the evidence clearly suggests periodic ultrasound surveillance for those with small AAAs (3.0-3.9 cm in diameter) and elective surgical repair for those with large AAAs (>or=5.5 cm). Two recent randomized controlled trials have shown that early surgical repair confers no survival benefit compared with periodic surveillance for patients with intermediate-sized AAAs (4.0-5.5 cm in diameter), so those patients can also be monitored. Some centers choose to increase the frequency of monitoring to every 3 to 6 months when the AAA reaches 5.0 cm. Factors to consider in assessing symptomatic patients include the high risk of life-threatening conditions, the potential increased risk of death or poor outcome with delay in diagnosis, the limitations of ultrasound in identifying whether symptoms are due to known or suspected AAA, and the timely availability of computed tomography or other imaging tests. If available, computed tomography is preferred in patients with recent or severe symptoms, since it is better at detecting retroperitoneal hemorrhage and other complications and in providing preoperative definition of the anatomy.

Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms

BACKGROUND

Two randomized trials have shown better outcomes with elective endovascular repair of abdominal aortic aneurysms than with conventional open repair in the first month after the procedure. We investigated whether this advantage is sustained beyond the perioperative period.

METHODS

We conducted a multicenter, randomized trial comparing open repair with endovascular repair in 351 patients who had received a diagnosis of abdominal aortic aneurysm of at least 5 cm in diameter and who were considered suitable candidates for both techniques. Survival after randomization was calculated with the use of Kaplan-Meier analysis and compared with the use of the log-rank test on an intention-to-treat-basis.

RESULTS

Two years after randomization, the cumulative survival rates were 89.6 percent for open repair and 89.7 percent for endovascular repair (difference, -0.1 percentage point; 95 percent confidence interval, -6.8 to 6.7 percentage points). The cumulative rates of aneurysm-related death were 5.7 percent for open repair and 2.1 percent for endovascular repair (difference, 3.7 percentage points; 95 percent confidence interval, -0.5 to 7.9 percentage points). This advantage of endovascular repair over open repair was entirely accounted for by events occurring in the perioperative period, with no significant difference in subsequent aneurysm-related mortality. The rate of survival free of moderate or severe complications was also similar in the two groups at two years (at 65.9 percent for open repair and 65.6 percent for endovascular repair; difference, 0.3 percentage point; 95 percent confidence interval, -10.0 to 10.6 percentage points).

CONCLUSIONS

The perioperative survival advantage with endovascular repair as compared with open repair is not sustained after the first postoperative year.

Management of Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAAs) are a lethal disease. Ultrasound is the modality of choice for screening patients for AAAs. It is reasonable to screen patients over age 60, particularly men, women with cardiovascular risk factors, smokers, and patients with a family history of AAAs. Patients with small (< 5.5 cm) AAAs should be followed with serial ultrasound. Medical management should focus on treating comorbidities, particularly those that put patients at risk for other cardiovascular diseases. Smoking cessation is mandatory in these patients. Patients with large or symptomatic AAAs should be evaluated for surgery; this includes careful imaging of the abdomen, aggressive treatment of comorbidities, and perioperative beta blockade. Endovascular repair has lower short-term morbidity compared with conventional open repair. Trials assessing long-term results are in progress. Basic science and translational research focusing on the underlying pathogenesis of AAAs will likely pave the way for medical therapies in the future.

Endovascular repair of abdominal aortic aneurysm reduces intraoperative cortisol and perioperative morbidity

BACKGROUND

The release of catabolic stress hormones because of surgical trauma leads to a breakdown of fats, proteins, and carbohydrate stores and interference with immune function. This can delay wound healing and may increase the risk of systemic inflammatory response syndrome (SIRS)/sepsis and postoperative complications. Minimally invasive surgery can attenuate this response. Our purpose was (1) to compare neuroendocrine responses in patients undergoing open abdominal aneurysm repair with those in patients undergoing endovascular aneurysm repair (EVAR), (2) to compare the incidence of SIRS/sepsis and all complications in these two groups, and (3) to look at the relationship between procedure type, neuroendocrine response, and incidence of SIRS/sepsis and complications.

METHODS

Forty-six patients who underwent open repair and 19 who underwent EVAR were studied. A baseline (T1) 24-hour urine save was undertaken in the week before admission, and a second 24-hour save (T2) commenced at anesthetic induction to measure cortisol and catecholamines. The incidences of SIRS/sepsis and complications were recorded.

RESULTS

Significant ( P </= .001) increases in cortisol and adrenaline from T1 to T2 occurred in all patients. Controlling for the type of anesthetic, the administration of exogenous inotropes, and beta-adrenoreceptor antagonists (beta-blockers), there was a significant difference in cortisol (T2) associated with the type of procedure. Responses were greater in open patients in comparison to EVAR patients (F 3,61 = 5.0; P = .03). The incidence of SIRS (50% vs 32%), sepsis (26% vs 5%), and all complications (76% vs 32%) was significantly ( P </= .02) higher in open than EVAR patients, respectively. Cortisol and adrenaline measured for 24 hours, commencing at the time of induction, tended to be higher in patients with SIRS/sepsis and all complications, but this did not reach significance.

CONCLUSIONS

An attenuated glucocorticoid surge characterizes the reduced stress response experienced by patients undergoing EVAR compared with open abdominal aortic aneurysm repair. A reduction in the occurrence of SIRS is a feature of a more favorable postoperative course after an endovascular approach.

To what extent has endovascular aneurysm repair influenced abdominal aortic aneurysm management in the state of Illinois?

PURPOSE

This study was performed using population-based data to determine the changing trends in the techniques for abdominal aortic aneurysm (AAA) repair in the state of Illinois during the past 9 years and to examine the extent to which endovascular aneurysm repair (EVAR) has influenced overall AAA management.

METHODS

All records of patients who underwent AAA repair (1995 to 2003 inclusive) were retrieved from the Illinois Hospital Association COMPdata database. The outcome as determined by in-hospital mortality was analyzed according to intervention type (open vs EVAR) and indication (elective repair vs ruptured AAA). Data were stratified by age, gender, and hospital type (university vs community setting) and then analyzed using both univariate (chi 2 , t tests) and multivariate (stepwise logistic regression) techniques.

RESULTS

Between 1995 and 2003, 14,517 patients underwent AAA repair (85% for elective and 15% for ruptured AAA). The average age was 71.4 +/- 7.9 years, and 76% were men. For elective cases, open repair was performed in 86% and EVAR in 14%; and for ruptured cases, open repair in 97% and EVAR in 3%. Elective EVAR was associated with lower in-hospital mortality compared with open repair regardless of age. No differences were observed with age after either type of repair for a ruptured aneurysm. Men had a lower in-hospital mortality compared with women for open repair of both elective and ruptured aneurysms. For EVAR, the mortality of an elective repair was lower in men, but there was no difference after a ruptured AAA. In men, the difference in mortality between elective open repair and EVAR was significant; the type of institution did not influence outcome. Patients >80 years of age had a higher mortality after open repair for both elective and ruptured AAA and after EVAR of a ruptured AAA. The average length of stay was 9.9 days for open elective repair, 13.1 days after open repair of a ruptured AAA, and 3.6 days for EVAR. The independent predictors of higher in-hospital mortality were female gender, age >80 years, diagnosis (ruptured vs open), and procedure (open vs EVAR). The year of the procedure and type of hospital (university vs community) were not predictive of outcome.

CONCLUSIONS

EVAR has had a significant impact on AAA management in Illinois over a relatively short time period. In this population-based review, EVAR was associated with a significantly decreased in-hospital mortality and length of stay. Octogenarians had higher mortality after both types of repair, with the exception of elective EVAR.

Delayed Complications Following EVAR

More than a decade after the first clinical attempts, two large randomized studies have proven that endovascular aortic aneurysm repair (EVAR) provides immediate advantages over open repair. In the long run, however, a relatively high number of reinterventions is necessary to improve the long-term efficacy of EVAR, which may outweigh the early benefits. Since EVAR is gaining popularity in the medical community and in patients with abdominal aortic aneurysm (AAA), it is expected that a growing number of patients will present with delayed complications requiring some kind of reinterventions. For the patient's safety, vascular surgeons and interventional radiologists involved in EVAR must be well aware of these complications and the ways to overcome them. We began our endovascular program for AAA in 1994 and currently follow 485 patients with a variety of manufactured grafts. In this article we describe the delayed complications observed with EVAR, their mechanisms, favoring factors, and ways to treat them.

Complications of major aortic and lower extremity vascular surgery

Atheromatous disease and invasive intervention of the aortoiliac and distal arteries are common. Morbidity and mortality have been reduced through understanding and management of patient risk factors. Complications of this form of treatment affect all organ systems; mortality is most frequently caused by a cardiovascular complication (eg, myocardial infarction). Infection, leading to aortoenteric fistula is a dreaded complication, and paraplegia, though rare, is a devastating outcome. Multiorgan failure and death may result from a systemic inflammatory response syndrome. Vascular surgery for infrainguinal disease also has a significant cardiovascular complication rate. Resulting complications may affect all organs; loss of an extremity may occur. The first part of this article reviews perioperative and postoperative complications of open aortic repair and lower-extremity revascularization and addresses the issue of regional anesthesia for major vascular surgery. The second part reviews endovascular aortic repair (EVAR). EVAR is a new intervention that combines surgery and radiology. Complications of EVAR are similar to open repair, but early results suggest they may be less frequent. New technology leads to new complications; endoleaks, migration of the endoprosthesis, and surgical conversion are unique to EVAR. The benefits of EVAR may be less blood loss, shorter hospitalization, and less cardiovascular stress; the risks may be aneurysm recurrence, prolonged surveillance and repeated secondary procedures. The development of EVAR, the complications, and the anesthesia-related concerns of EVAR, including its use in management of acute abdominal aortic aneurysm are reviewed.

A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms

BACKGROUND

Although the initial results of endovascular repair of abdominal aortic aneurysms were promising, current evidence from controlled studies does not convincingly show a reduction in 30-day mortality relative to that achieved with open repair.

METHODS

We conducted a multicenter, randomized trial comparing open repair with endovascular repair in 345 patients who had received a diagnosis of abdominal aortic aneurysm of at least 5 cm in diameter and who were considered suitable candidates for both techniques. The outcome events analyzed were operative (30-day) mortality and two composite end points of operative mortality and severe complications and operative mortality and moderate or severe complications.

RESULTS

The operative mortality rate was 4.6 percent in the open-repair group (8 of 174 patients; 95 percent confidence interval, 2.0 to 8.9 percent) and 1.2 percent in the endovascular-repair group (2 of 171 patients; 95 percent confidence interval, 0.1 to 4.2 percent), resulting in a risk ratio of 3.9 (95 percent confidence interval, 0.9 to 32.9). The combined rate of operative mortality and severe complications was 9.8 percent in the open-repair group (17 of 174 patients; 95 percent confidence interval, 5.8 to 15.2 percent) and 4.7 percent in the endovascular-repair group (8 of 171 patients; 95 percent confidence interval, 2.0 to 9.0 percent), resulting in a risk ratio of 2.1 (95 percent confidence interval, 0.9 to 5.4).

CONCLUSIONS

On the basis of the overall results of this trial, endovascular repair is preferable to open repair in patients who have an abdominal aortic aneurysm that is at least 5 cm in diameter. Long-term follow-up is needed to determine whether this advantage is sustained.

Minimally invasive retroperitoneal approach for the treatment of infrarenal aortic disease

PURPOSE

In order to decrease complications and improve postoperative recovery, we have developed a minimally invasive retroperitoneal approach (MIRPA) for the treatment of infrarenal aortic disease. This study was carried out to define the limitations and applicability of this technique in the treatment of aortoiliac occlusive disease (AIOD) and abdominal aortic aneurysms (AAAs).

METHODS

From November 2000 to February 2004, 150 patients with AAA (n = 130) or AIOD (n = 20) were prospectively included in the study. The procedure consisted in a standard aneurysmorrhaphy or bypass procedure performed through a video assisted left minilombotomy.The main outcomes measured were mortality, complications, operative time, aortic cross-clamp time, time to solid diet, and length of intensive care unit and hospital stay.

RESULTS

Operative mortality was 0.7 %. Nonfatal postoperative complications occurred in 12 patients (8%). Conversion to a standard procedure was necessary in 3 patients. Mean operative time was 207 +/- 57 minutes (AAA) and 224 +/- 55 minutes (AIOD). Mean aortic cross-clamp time was 76 +/- 26 minutes (AAA) and 48 +/- 21 minutes (AIOD). Median resumption of regular diet was 2 days. Median length of stay in the intensive care unit was 1 day and in the hospital 8 days.

CONCLUSION

Our results suggest that MIRPA is a safe and effective minimally invasive procedure in the treatment of infrarenal aortic disease.

Perioperative outcomes after open and endovascular repair of intact abdominal aortic aneurysms in the united states during 2001

OBJECTIVE

Small patient numbers, mixed data from clinical trials, and longitudinal series representing institutional learning curves have characterized previous studies of early outcomes after endovascular abdominal aortic aneurysm (AAA) repair. We compared the perioperative outcomes of endovascular and open surgical AAA repair in an unselected sample of patients in a single calendar year using a national administrative database.

METHODS

The 2001 National Inpatient Sample database was retrospectively reviewed. This database represents 20% of all-payer stratified sample of non-federal US hospitals. Patients older than 49 years were identified by primary diagnostic codes (International Classification of Disease, ninth revision [ICD-9], 441.4, intact, nonruptured AAA) and procedure codes (ICD-9 38.44 for open, 39.71 for endovascular repair). Patient demographic data (age, sex), comorbid conditions (ICD-9 coded), inpatient complications (ICD-9 coded), length of stay, final discharge disposition (home vs institution vs death), and hospital charges were examined with univariate and multivariate analyses.

RESULTS

In calendar year 2001, 7172 patients underwent either open (64%) or endovascular (36%) repair of intact, nonruptured AAAs. Despite comparable rates of preoperative comorbid conditions and a greater proportion of octogenarians (23% vs 16%%; P =.0001), morbidity (18% vs 29%; P =.0001) and mortality (1.3% vs 3.8%; P =.0001) were significantly lower for endovascular repair than for open repair. The median length of stay (2 vs 7 days; P =.0001) and the rate of discharge to an institutional facility versus home (6% vs 14%; P =.0001) were also much lower in the endovascular group than in the open repair group. At multivariate analysis, open AAA repair and age older than 80 years were strong independent predictors (P =.0001 for all) for death (open repair: odds ratio [OR], 3.3; 95% confidence interval [CI], 2.3-4.9; age: OR, 14.2; 95% CI, 3.5-58.1), complications (open repair: OR, 1.9; 95% CI, 1.7-2.1; age: OR, 1.9; 95% CI, 1.5-2.5), and not being discharged to home (open repair: OR, 3.4; 95% CI, 2.9-4.1; age: OR, 12.0; 95% CI, 7.0-20.4). Mean hospital charges were significantly greater (difference, $3337; P =.0009) for endovascular repair than for open repair. Extrapolated to the total number of endovascular AAA repairs performed during the single 2001 calendar year, this resulted in a staggering $50.3 million in additional hospital charges.

CONCLUSIONS

Endovascular repair of intact AAAs results in a significantly lower number of complications and deaths, shorter hospital stay, and improved likelihood of discharge to home, even in older patients, when compared with open surgical repair. These impressive gains in clinical outcome, however, are achieved at similarly impressive increases in health care costs.