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

Hospital resource use and costs among abdominal aortic aneurysm repair patients admitted to the intensive care unit

BACKGROUND

Abdominal aortic aneurysm (AAA) repair is associated with significant morbidity and mortality. As a result, many of these patients are monitored postoperatively in the intensive care unit (ICU). However, little is known about resource utilization and costs associated with ICU admission in this population. We sought to evaluate predictors of total costs among patients admitted to the ICU after repair of nonruptured or ruptured AAA.

METHODS

We retrospectively analyzed prospectively collected data (2011-2016) of ICU patients admitted after AAA repair. The primary outcome was total hospital costs. We used elastic net regression to identify pre-ICU admission predictors of hospitalization costs separately for nonruptured and ruptured AAA patients.

RESULTS

We included 552 patients in the analysis. Of these, 440 (79.7%) were admitted after repair of nonruptured AAA, and 112 (20.3%) were admitted after repair of ruptured AAA. The mean age of patients with nonruptured AAA was 74 (standard deviation, 9) years, and the mean age of patients with ruptured AAA was 70 (standard deviation, 8) years. Median total hospital cost (in Canadian dollars) was $21,555 (interquartile range, $17,798-$27,294) for patients with nonruptured AAA and $33,709 (interquartile range, $23,173-$53,913) for patients with ruptured AAA. Among both nonruptured and ruptured AAA patients, increasing age, illness severity, use of endovascular repair, history of chronic obstructive pulmonary disease, and excessive blood loss (≥4000 mL) were associated with increased costs, whereas having an anesthesiologist with vascular subspecialty training was associated with lower costs.

CONCLUSIONS

Patient-, procedure-, and clinician-specific variables are associated with costs in patients admitted to the ICU after repair of AAA. These factors may be considered future targets in initiatives to improve cost-effectiveness in this population.

Editor's Choice - Prolonged ICU Length of Stay after AAA Repair: Analysis of Time Trends and Long-term Outcome

OBJECTIVE

The aim of the study was to investigate the frequency and outcome of prolonged intensive care unit (ICU) length of stay (LOS) after abdominal aortic aneurysm (AAA) repair in the endovascular era.

METHODS

All patients operated on for AAA between 1999 and 2013 at Uppsala University hospital were identified. Data were retrieved from the Swedish Vascular registry, the Swedish Intensive Care registry, the National Population registry, and case records. Prolonged ICU LOS was defined as ≥ 48 h during the primary hospital stay. Patients surviving ≥ 48 h after AAA surgery were included in the analysis.

RESULTS

A total of 725 patients were identified, of whom 707 (97.5%) survived ≥ 48 h; 563 (79.6%) underwent intact AAA repair and 144 (20.4%) ruptured AAA repair. A total of 548 patients (77.5%) required < 48 h of intensive care, 115 (16.3%) 2-6 days and 44 (6.2%) ≥ 7 days. The rate of prolonged ICU LOS declined considerably over time, from 41.4% of all AAA repairs in 1999 to 7.3% in 2013 (p < .001) whereas the use of endovascular aortic repair (EVAR) increased from 6.9% in 1999 to 78.0% in 2013 (p < .001). The 30 day survival rate was 98.2% for those with < 48 h ICU stay versus 93.0% for 2-6 days versus 81.8% for ≥ 7 days (p < .001); the corresponding 90 day survival was 97.1% versus 86.1% versus 63.6% (p < .001) respectively. For patients surviving 90 days after repair, there was no difference in long-term survival between the groups.

CONCLUSION

During the period of progressively increasing use of EVAR, a simultaneous significant reduction in frequency of prolonged ICU LOS occurred. Although prolonged ICU LOS was associated with a high short-term mortality, long-term outcome among those surviving the initial 90 days was less affected.

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.

Rates of adverse events and correction procedures after elective versus emergent aortouni-iliac endografting during mid-term follow-up: A prospective cohort study

BACKGROUND

Due to preferential implantation of bifurcated devices during endovascular repair of infrarenal abdominal aortic aneurysms (AAA), longer-term results following aortouni-iliac (AUI) endografting are scarce. The aim of this study was to determine the rate of endoleaks as well as frequency of secondary correction procedures after elective and emergent AUI endografting.

METHODS

A prospectively gathered database at a tertiary care university hospital was retrospectively reviewed from January 2000 until January 2012. This interrogation identified 61 patients who had undergone AUI endografting to treat their AAA. Data retrieval obtained 47 patients with elective AAA repairs while 14 patients received emergent AUI endografting in case of rupture. Procedural outcomes, endoleaks, complications, and secondary interventions during mid-term follow-up were recorded for analysis.

RESULTS

Fifty-five patients of the study cohort were male (90.2%) and mean age was 76.5 years (median: 77.2, Q1-Q3: 72.1-81.6). Patient demographics, comorbidities, procedural characteristics, as well as median follow-up length (39.8 months versus 34.9 months) were similar between groups. Endoleaks, complications, and rate of secondary correction procedures were not increased following emergent AUI endografting. The majority of these interventions comprised catheter-based or less invasive surgical procedures. All patients requiring major surgery (three open surgical conversions with endograft explantation and one open aortic banding) survived, while one patient sustained fatal myocardial infarction after a transluminal correction procedure.

CONCLUSION

Emergent AUI endografting was not associated with higher rates of adverse events or correction procedures during mid-term follow-up. Secondary interventions to maintain aneurysm exclusion could be carried out with low mortality.

Duplex Ultrasound versus Computed Tomography for the Postoperative Follow-Up of Endovascular Abdominal Aortic Aneurysm Repair. Where Do We Stand Now?

In the last decade, endovascular aneurysm repair (EVAR) has rapidly developed to be the preferred method for infrarenal abdominal aortic aneurysm repair in patients with suitable anatomy. EVAR offers the advantage of lower perioperative mortality and morbidity but carries the cost of device-related complications such as endoleak, graft migration, graft thrombosis, and structural graft failure. These complications mandate a lifelong surveillance of EVAR patients and their endografts. The purpose of this study is to review and evaluate the safety of color-duplex ultrasound (CDU) as compared with computed tomography (CT), based on the current literature, for post-EVAR surveillance. The post-EVAR follow-up modalities, CDU versus CT, are evaluated questioning three parameters: (1) accuracy of aneurysm size, (2) detection and classification of endoleaks, and (3) detection of stent-graft deformation. Studies comparing CDU with CT scan for investigation of post-EVAR complications have produced mixed results. Further and long-term research is needed to evaluate the efficacy of CDU versus CT, before CDU can be recommended as the primary imaging modality for EVAR surveillance, in place of CT for stable aneurysms.

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.

Endovascular treatment of delayed rupture following prior abdominal aortic aneurysm repair achieves better survival rates

PURPOSE

To test the hypothesis that endovascular treatment of delayed aneurysm rupture achieves significantly better survival rates compared to surgical conversion.

METHODS

All patients sustaining delayed rupture following prior exclusion of an abdominal aortic aneurysm (AAA) either by endovascular aneurysm repair (EVAR) or open graft replacement from March 1995 through December 2011 were retrieved from a prospectively maintained database at a tertiary care university hospital. During the study period, 35 patients (32 men; mean age 72.9 years) presented with delayed rupture at a median 2.4 years (interquartile range 1.3-4.3) after initial AAA repair by EVAR (n=22) or open surgery (n=13). Causes of post-EVAR rupture were graft-related endoleaks, while ruptures after open repair occurred at anastomotic suture sites. Patients were divided into groups regarding type of treatment for delayed rupture: 20/35 (57%) underwent successful EVAR (10 redo procedures), 13/35 (37%) had surgery (3 redo procedures), and 2/35 (6%) patients received comfort care only. The primary endpoint was 30-day mortality.

RESULTS

The 30-day mortality after curative treatment was 25% (5/20) for endovascular treatment compared to 54% (7/13) for surgery (p=0.14). Including additional deaths beyond 30 days, the overall in-hospital mortality was 52% (17/33). The Kaplan-Meier survival estimate for patients undergoing endovascular treatment was significantly higher (p=0.011).

CONCLUSION

Endovascular treatment of delayed rupture is feasible and helps to reduce mortality. Our data suggest that endovascular procedures are a superior treatment option for EVAR-suitable patients with delayed rupture compared with surgical conversion.

Clinical practice change requires more than comparative effectiveness evidence: abdominal aortic aneurysm management in the USA

Adoption of healthcare innovations frequently outpaces the evidence of effectiveness. Endovascular repair (EVAR) for abdominal aortic aneurysms in the USA demonstrates how comparative effectiveness research without evidence-based reimbursement changes may fail to influence clinical practice. Randomized controlled trials for small abdominal aortic aneurysms demonstrate no lasting benefits of EVAR or open surgical repair (OSR) compared with surveillance, and for large abdominal aortic aneurysms demonstrate no lasting survival benefit of EVAR over OSR, and do show poorer durability and higher costs for EVAR. Nonetheless, >50% of elective abdominal aortic aneurysm repairs in the USA use EVAR. Factors that may be driving the high use of EVAR include patient preference, surgeons’ desire to appear ‘up-to-date’ in the procedures they offer, higher hourly surgeon reimbursement for EVAR than OSR, and the expansion of physician specialties able to perform abdominal aortic aneurysm repair from only vascular surgeons with OSR, to vascular surgeons and interventional radiologists/cardiologists with EVAR. By comparison, in Canada, where government health insurance restricts EVAR coverage to high surgical risk patients, only approximately 25% of abdominal aortic aneurysm repairs are performed using EVAR. Country-specific cost studies and a prospective population-based study collecting detailed clinical data to identify patient subgroups that truly benefit from a particular management strategy are needed to inform policy regarding EVAR availability and reimbursement.

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.

Outcomes of care of abdominal aortic aneurysm in Veterans Health Administration facilities: results from the National Surgical Quality Improvement Program

This report describes outcomes of care for abdominal aortic aneurysms (AAAs), along with methods used by the Veterans Affairs (VA) National Surgical Quality Improvement Program (NSQIP) in tracking, monitoring, and improving surgical results in VA facilities. Since the inception of NSQIP in 1994, a continual drop in overall surgical mortality, along with decreased morbidity, has occurred. A parallel improvement in results of vascular surgery and AAA repair was also observed. Soon after introduction of endovascular aneurysm repair (EVAR), with Food and Drug Administration device approval in 1999, robust electronic NSQIP records immediately began to capture individual facility performances and outcomes for both types of AAA repair. The NSQIP data center provided actual and risk-adjusted analyses for both procedures semiannually. These analyses have been used by its executive board to provide recommendations, often based on site visits, to improve outcomes. Requirements for reporting of facility-specific data and feedback, paper audits, and site visits appear to relate directly to improved AAA care. Veterans Health Administration (VHA) outcomes of AAA repair are comparable to those reported nationally and internationally and have continued to improve in recent years. National VHA initiatives, based on data feedback and active oversight, relate to some of the lowest AAA mortality rates available. This review describes past, present, and possible future NSQIP strategies to improve outcomes for AAA repair with general comments about recent alternative proposals.