Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial

Adjuvant Procedures Performed During Endovascular Repair of Abdominal Aortic Aneurysm. Does it Influence Outcome?

OBJECTIVE

The purpose of this study was to assess whether there is a difference in outcome of endovascular repair in patients with and without intraoperative adjuvant procedures.

METHODS

Demographic, anatomic and operative details were assessed in patients undergoing endovascular repair using the EUROSTAR registry and correlated with morbidity and mortality rates. Three groups of adjuvant procedures: (A) endovascular, (B) surgical peripheral arterial and (C) surgical abdominal arterial were compared with a group of patients without an adjuvant procedure (D). Logistic regression and Cox proportional hazards model were used for statistical analysis.

RESULTS

Of 4631 endovascular repairs, 1353 patients (29.2%) required adjuvant procedures. Additional endovascular procedures were performed in 1057 (78.1%), surgical peripheral arterial in 193 (14.3%) and surgical abdominal arterial in 103 (7.6%). The 30-day mortality rate was significantly higher in categories with peripheral arterial surgical (6.7%) and abdominal surgical procedures (7.8%) compared to patients without adjuvant procedures (1.5%, p = .001 and p = .004, respectively). Life-table-analysis demonstrated that late mortality, conversion or rupture rates were not increased in patients with an adjuvant procedure.

CONCLUSION

Adjuvant surgical procedures were associated with increased 30-day mortality. Because of this higher risk, endovascular repair should be recommended with caution when surgical adjuvant procedures are anticipated.

The Management of Abdominal Aortic Aneurysms in Patients with Concurrent Renal Impairment

INTRODUCTION

Patients with concurrent renal impairment and abdominal aortic aneurysms present a significant challenge in terms of pre-operative, intra-operative and post-operative management. This aim of this review was to determine the risks of surgery in this patient group and determine whether any clear management strategies exist to enhance their clinical management.

METHODS

Systematic review of published literature giving details of the outcome of open or endovascular abdominal aortic aneurysm repair in patients with pre-operative renal impairment. Papers concerning the management of post-operative acute renal failure in patients with normal pre-operative renal function has not been included.

RESULTS

There is little data regarding patients with end-stage renal failure and AAA although these patients appear to have a high peri-operative mortality rate. In contrast, those with renal impairment do not have a significantly higher mortality rate than those with normal renal function, rather they have a higher risk of complications associated with surgery and may require more intensive post-operative organ system support than normal patients. Many have a transient deterioration in renal function in the immediate peri-operative period that will resolve. In the case of patients with ruptured AAA, it is not clear whether pre-operative renal impairment affects mortality.

Endovascular aneurysm repair versus open repair in patients with abdominal aortic aneurysm (EVAR trial 1): randomised controlled trial

BACKGROUND

Although endovascular aneurysm repair (EVAR) has a lower 30-day operative mortality than open repair, the long-term results of EVAR are uncertain. We instigated EVAR trial 1 to compare these two treatments in terms of mortality, durability, health-related quality of life (HRQL), and costs for patients with large abdominal aortic aneurysm (AAA).

METHODS

We did a randomised controlled trial of 1082 patients aged 60 years or older who had aneurysms of at least 5.5 cm in diameter and who had been referred to one of 34 hospitals proficient in the EVAR technique. We assigned patients who were anatomically suitable for EVAR and fit for an open repair to EVAR (n=543) or open repair (n=539). Our primary endpoint was all-cause mortality, with secondary endpoints of aneurysm related mortality, HRQL, postoperative complications, and hospital costs. Analyses were by intention to treat.

FINDINGS

94% (1017 of 1082) of patients complied with their allocated treatment and 209 died by the end of follow-up on Dec 31, 2004 (53 of aneurysm-related causes). 4 years after randomisation, all-cause mortality was similar in the two groups (about 28%; hazard ratio 0.90, 95% CI 0.69-1.18, p=0.46), although there was a persistent reduction in aneurysm-related deaths in the EVAR group (4%vs 7%; 0.55, 0.31-0.96, p=0.04). The proportion of patients with postoperative complications within 4 years of randomisation was 41% in the EVAR group and 9% in the open repair group (4.9, 3.5-6.8, p<0.0001). After 12 months there was negligible difference in HRQL between the two groups. The mean hospital costs per patient up to 4 years were UK pound sterling 13,257 for the EVAR group versus pound sterling 9946 for the open repair group (mean difference pound sterling 3311, SE 690).

INTERPRETATION

Compared with open repair, EVAR offers no advantage with respect to all-cause mortality and HRQL, is more expensive, and leads to a greater number of complications and reinterventions. However, it does result in a 3% better aneurysm-related survival. The continuing need for interventions mandates ongoing surveillance and longer follow-up of EVAR for detailed cost-effectiveness assessment.

Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial

BACKGROUND

Endovascular aneurysm repair (EVAR) to exclude abdominal aortic aneurysm (AAA) was introduced for patients of poor health status considered unfit for major surgery. We instigated EVAR trial 2 to identify whether EVAR improves survival compared with no intervention in patients unfit for open repair of aortic aneurysm.

METHODS

We did a randomised controlled trial of 338 patients aged 60 years or older who had aneurysms of at least 5.5 cm in diameter and who had been referred to one of 31 hospitals in the UK. We assigned patients to receive either EVAR (n=166) or no intervention (n=172). Our primary endpoint was all-cause mortality, with secondary endpoints of aneurysm-related mortality, health-related quality of life (HRQL), postoperative complications, and hospital costs. Analyses were by intention to treat.

FINDINGS

197 patients underwent aneurysm repair (47 assigned no intervention) and 80% of patients adhered to protocol. The 30-day operative mortality in the EVAR group was 9% (13 of 150, 95% CI 5-15) and the no intervention group had a rupture rate of 9.0 per 100 person years (95% CI 6.0-13.5). By end of follow up 142 patients had died, 42 of aneurysm-related factors; overall mortality after 4 years was 64%. There was no significant difference between the EVAR group and the no intervention group for all-cause mortality (hazard ratio 1.21, 95% CI 0.87-1.69, p=0.25). There was no difference in aneurysm-related mortality. The mean hospital costs per patient over 4 years were UK pound sterling 13,632 in the EVAR group and pound sterling 4983 in the no intervention group (mean difference pound sterling 8649, SE 1248), with no difference in HRQL scores.

INTERPRETATION

EVAR had a considerable 30-day operative mortality in patients already unfit for open repair of their aneurysm. EVAR did not improve survival over no intervention and was associated with a need for continued surveillance and reinterventions, at substantially increased cost. Ongoing follow-up and improved fitness of these patients is a priority.

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.

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.

Results from the Prospective Registry of Endovascular Treatment of Abdominal Aortic Aneurysms (RETA): Mid Term Results to Five Years

OBJECTIVES

To assess the mid-term outcomes up to 5 years following endovascular repair of abdominal aortic aneurysms (EVAR), following its initial introduction into practice in the UK.

DESIGN

A prospective voluntary Registry of Endovascular Treatment of Aneurysms (RETA) collected demographic and risk factor data, short term (30 day) outcomes and follow up outcomes up to 5 years from the 41 centres that initially undertook EVAR in the UK.

RESULTS

Short term outcomes (30 days): 90.4% of aneurysms were successfully excluded, 6.1% had persistent endoleaks and 5.8% of patients had died. Follow up was obtained from 30 days up to 5 years (mean 3.1 years). Returns rates for requested follow up data were 87% at 1 year and 77, 65, 52 and 51% at 2, 3, 4 and 5 years, respectively. Ninety percent of deaths at follow up were unrelated to the stent-graft or aneurysm. Persistent proximal type I endoleak was associated with significant mortality both from attempted open repair or from rupture if untreated. Other endoleaks were more benign. Complications related to the aneurysm or device occurred at an average rate of 15% per annum. The most common complications were secondary endoleaks or graft migration. Endovascular treatment was preferred if treatment was necessary for graft complications. The cumulative freedom from secondary procedure (Kaplan-Meier) were 87, 77, 70, 65 and 62% at 1, 2, 3, 4 and 5 years of follow up, respectively.

CONCLUSIONS

Registry data provides useful information to guide the design of more formal trials. Collecting follow up from voluntarily submitted data is difficult. The registry data remains well ahead of the trial data, but indicate that long term follow up is required in these trials, because of the high rate of complications seen at follow up.

Endovascular AAA Repair With the Aortomonoiliac EndoFit Stent-Graft: Two Years' Experience

PURPOSE

To evaluate the feasibility and efficacy of a specific aortomonoiliac endograft and the durability of the femorofemoral bypass for treatment of abdominal aortic aneurysm (AAA).

METHODS

From 2002 to 2004, 39 high-risk (ASA III/IV) patients (36 men; median age 74 years, range 63-84) with AAA (n = 33) or AAA and common iliac artery aneurysm (n = 6) were treated with an EndoFit aortomonoiliac endograft and femorofemoral crossover bypass. The contralateral iliac axis was obstructed with an endoluminal occluder. Patients were followed with contrast-enhanced computed tomography at 1, 6, 12, and 24 months.

RESULTS

EndoFit AMI stent-grafts were implanted successfully in all patients. Perioperative mortality was zero. Endoleak occurred in 3 (7.7%) cases. A proximal type I endoleak was identified at 1 month and was treated with a proximal cuff. Two type II endoleaks are under surveillance because the aneurysm sac shows no enlargement. Thrombosis of the femorofemoral graft occurred in 1 case during the immediate postoperative period due to insufficient inflow from a residual stenosis of the endograft (primary patency 97.5%). The deficit was treated successfully (secondary patency 100%). Two (5.1%) tunnel hematomas were treated conventionally. Median follow-up was 14 months (range 6-30). All patients are alive. None of the aneurysms has ruptured or been converted to an open procedure. Graft migration, serious infection, paraplegia, distal embolization, or any other serious complication has not been observed.

CONCLUSIONS

In high surgical risk patients with complex iliac anatomy, aortomonoiliac endograft with femorofemoral crossover bypass is feasible and efficacious. Moreover, the midterm patency of the extra-anatomic bypass appears quite satisfactory.

Influence of Diabetes Mellitus on the Endovascular Treatment of Abdominal Aortic Aneurysms

PURPOSE

To investigate the influence of diabetes mellitus on outcome after endovascular abdominal aortic aneurysm (AAA) repair.

METHODS

Of 6017 patients enrolled in the EUROSTAR registry after undergoing endovascular AAA repair between May 1994 and December 2003, 731 (12%) had diabetes mellitus (690 men; mean age 72 years, range 37-100). Patient demographics, risk factors, aneurysm morphology, operative and procedural details, complications, major events, and regular follow-up information were compared. The relationships of complications and events to diabetes mellitus, which were tested with multivariate logistic regression analysis and Cox proportional hazards modeling, are expressed as odds ratios (OR) and hazard rates (HR) with 95% confidence intervals (CI). Survival was compared with life-table analysis.

RESULTS

A significantly higher risk of device-related complications was observed in diabetic patients (8% versus 6%, p < 0.049; OR 1.35, 95% CI 1.00 to 1.82). The greatest difference in the groups was in mortality, which was significantly higher in the diabetic population (13%) compared to the nondiabetic patients (10%, p < 0.039; OR 1.27, 95% CI 1.01 to 1.59). Deaths, which occurred at a higher frequency within the 30-day perioperative period in diabetic patients, were primary due to cardiac complications. Insulin-controlled type 2 diabetic patients had significantly lower rates of early and late endoleaks and secondary interventions than diet-controlled type 2 diabetics (p = 0.002, p = 0.0001, and p = 0.0008, respectively) and nondiabetic patients (p = 0.002, p = 0.0005, and p = 0.0025, respectively). The cumulative survival after 48 months did not differ significantly: 74% in diabetics and 79% in the population without diabetes.

CONCLUSIONS

Patients with diabetes mellitus had a significantly higher early mortality rate after EVAR, but their long-term survival was similar to nondiabetic patients.

Cost-effectiveness of different screening strategies for abdominal aortic aneurysm

OBJECTIVE

The primary objective of this study was to develop a simulation model to assess the cost-effectiveness of different screening strategies for abdominal aortic aneurysms (AAAs) in men.

METHODS

A systematic review of the literature was conducted for different screening strategies in terms of age (60, 65, or 70 years) and risk profiles (all men or specific high-risk groups) of the screened population, and rescreening after 5 or 10 years. These data were analyzed in a Markov simulation cohort model.

RESULTS

The cost per life year gained for different screening strategies ranged from US 8,309 dollars to US 14,084 dollars and was estimated at US 10,474 dollars when 65-year-old men were screened once. Screening 60-year-old men was equally cost-effective, with the advantage of more life years gained. We demonstrated a trade-off between high prevalence of AAA and lower life expectancy, eliminating the expected benefits of screening high-risk groups such as smokers (US 10,695 dollars) or cardiovascular patients (US 10,392 dollars). Assuming general population utility resulted in a cost per quality-adjusted life year (QALY) gained of US 13,900 dollars, whereas a hypothetical 5% reduction in utility among men with a screening-detected AAA raised the cost per QALY gained to US 75,100 dollars.

CONCLUSION

This Markov model, which was based on a systematic review of the literature, supplied information on the estimated cost-effectiveness of different screening strategies. Screening men for AAA may be cost-effective in the long-term. Different screening strategies and quality-of-life effects related to screening for AAA need to be evaluated in future clinical studies.

Endograft technology: highlights of the past 10 years

The past decade has seen the evolution of an exciting technology that has changed forever the treatment of aortic aneurysmal disease. From rather crude homemade stent-grafts constructed in the surgical suite to elegant commercially manufactured devices in a variety of configurations and sizes, the aortic endograft has experienced a meteoric rise in popularity to become a beneficial, minimally invasive therapy that can obviate the risk of rupture and death. There are now 3 approved endovascular devices on the market for infrarenal abdominal aortic aneurysm repair, and it is likely that additional and improved devices will become available in the future. This review revisits the developmental history of the aortic endograft, noting the ongoing refinements that have arisen from our experiences with the growing population of stent-graft patients. Although research continues to search for solutions to the problems of endoleak and migration, long-term results even with the earlier second and third-generation devices are better than has been achieved with open surgical repair.

Endovascular Treatment of Acute Abdominal Aortic Aneurysm with a Bifurcated Stentgraft

OBJECTIVES

To analyse the results of emergency endovascular aneurysm repair (eEVAR) for acute abdominal aortic aneurysms (AAA), in comparison to open repair, and to evaluate suitability and application rate.

PATIENTS AND METHODS

All patients treated for an acute AAA between January 1998 and August 2004 were included. The primary outcome measure was in-hospital mortality. Secondary outcome measures were procedure time, intra-operative blood loss, transfusion requirement, intensive care unit, and hospital length of stay. Suitability and application rate for eEVAR were assessed in a subgroup of patients, from January 2003.

RESULTS

A total of 253 patients were treated. eEVAR was performed in 40 patients, 5 (13%) died in-hospital. Open repair was performed in 213 patients, 64 (30%) died in-hospital. Secondary outcome measures were all significantly improved in the eEVAR subgroup. From January 2003, 56 patients were treated. Of the 44 (79%) patients who were evaluated for eEVAR, 16 (36%) patients were anatomically suitable. Eventually, 15 out of the 56 (27%) patients were treated by eEVAR.

CONCLUSION

The results of eEVAR in a selected group of patients are promising, but suitability and application rate were low.

Midterm outcome of endovascular repair of ruptured abdominal aortic aneurysms

PURPOSE

We sought to analyze the clinical and morphologic outcomes of bifurcated stent grafts in patients with ruptured aortoiliac aneurysms at midterm follow-up.

METHODS

Thirty-seven patients (4 women; mean age, 73 years; mean abdominal aortic aneurysm [AAA] diameter, 77 mm) underwent endovascular abdominal aneurysm repair between June 1997 and July 2003 for ruptured AAA. Devices inserted were as follows: Vanguard (Boston Scientific, Natick, Mass; n = 7), Excluder (W.L. Gore, Flagstaff, Ariz; n = 25), Talent (Medtronic Vascular, Santa Rosa, Calif; n = 2), and Zenith (Cook Inc, Bloomington, Ind; n = 3). Except for the adjunct postimplantation computed tomographic scanning, the imaging follow-up was the same as for nonruptured AAAs.

RESULTS

The mean follow-up period was 24 months (range, 1-59) months. Thirty-day mortality was 10.8%. Three patients died during the follow-up of non-AAA-related causes. One patient was converted early for presumed renal overstenting. The late conversion rate was 9% because of stent graft migration (n = 2) or infection (n = 1). Freedom from endoleak was 57% +/- 8.5% and 48.8% +/- 9% at 2 and 4 years, respectively. Seventeen secondary interventions were performed during the follow-up period, 41% of these within 1 month of stent graft placement. Endoleaks, primary or secondary, were responsible for 58.8% of these interventions. The cumulative risk of a secondary intervention was 35.3% +/- 9% at 2 years and 44.6% +/- 11% at 3 years. Aneurysmal sac shrinkage was observed in 30.8% +/- 9.1% and sac enlargement was observed in 15.3% +/- 10.8% at 2 years.

CONCLUSION

Endoluminal devices are able to convert the acute life-threatening situation of ruptured AAA to a controlled situation that results in good patient survival at midterm follow-up.

Elective Open Operation for Abdominal Aortic Aneurysm in Octogenarians—Survival Analysis of 105 Patients

OBJECTIVES

To study early mortality and long-term survival of patients more than 80 years of age having elective open repair for abdominal aortic aneurysm (AAA).

DESIGN

Retrospective multicenter cohort study.

MATERIAL

One hundred and five patients, 23 women and 82 men, with a median age of 82 years, operated at three Norwegian hospitals during the period 1983-2002.

METHOD

Survival analyses were based on data from medical records and the Norwegian Registrar's Office of Births and Deaths. Expected survival was based on mortality rates of the general population, matched by age, sex, and calendar period. Relative survival was calculated as the ratio between the observed and the expected survival.

RESULTS

During the study period there has been a 10 fold increase in octogenarians treated with open operation for AAA. Early mortality (30-day) for the whole group of patients was 10.5% (95% confidence interval (95% CI) 5.3-18.0), and similar for both genders. The 5-year survival rate was 47% (95% CI 35.9-57.4), and not significantly different from that of a matched group in the general population. Patients aged 84 years or more had a median survival time of 35 months (95% CI 18.5-51.6).

CONCLUSION

The number of AAA operations in octogenarians has increased considerably during 20 years. Octogenarians operated electively for AAA has higher 30-day mortality as compared to younger patients. Their long-term survival appears similar to a matched control group. The benefit of surgery must be carefully considered against the perioperative risk, especially for the oldest octogenarians.

Endovascular Repair or Surveillance of Patients with Small AAA

OBJECTIVE

To compare the outcome of patients with small abdominal aortic aneurysms (AAA) treated in a prospective trial of endovascular aneurysm repair (EVAR) to patients randomized to the surveillance arm of the UK Small Aneurysm Trial.

METHOD

All patients with small AAA (< or = 5.5 cm diameter) treated with a stent graft (EVARsmall) in the multicenter AneuRx clinical trial from 1997 to 1999 were reviewed with follow up through 2003. A subgroup of patients (EVARmatch) who met the age (60-76 years) and aneurysm size (4.0-5.5 cm diameter) inclusion criteria of the UK Small Aneurysm Trial were compared to the published results of the surveillance patient cohort (UKsurveil) of the UK Small Aneurysm Trial (NEJM 346:1445, 2002). Endpoints of comparison were aneurysm rupture, fatal aneurysm rupture, operative mortality, aneurysm related death and overall mortality. The total patient years of follow-up for EVAR patients was 1369 years and for UK patients was 3048 years. Statistical comparisons of EVARmatch and UKsurveil patients were made for rates per 100 patient years of follow up (/100 years) to adjust for differences in follow-up time.

RESULTS

The EVARsmall group of 478 patients comprised 40% of the total number of patients treated during the course of the AneuRx clinical trial. The EVARmatch group of 312 patients excluded 151 patients for age < 60 or > 76 years and 15 patients for AAA diameter < 4 cm. With the exception of age, there were no significant differences between EVARsmall and EVARmatch in pre-operative factors or post-operative outcomes. In comparison to the UKsurveil group of 527 patients, the EVARmatch group was slightly older (70 +/- 4 vs. 69 +/- 4 years, p = 0.009), had larger aneurysms (5.0 +/- 0.3 vs. 4.6 +/- 0.4 cm, p < 0.001), fewer women (7 vs. 18%, p < 0.001), and had a higher prevalence of diabetes and hypertension and a lower prevalence of smoking at baseline. Ruptures occurred in 1.6% of EVARmatch patients and 5.1% of UKsurveil patients; this difference was not significant when adjusted for the difference in length of follow up. Fatal aneurysm rupture rate, adjusted for follow up time, was four times higher in UKsurveil (0.8/100 patient years) than in EVARmatch (0.2/100 patient years, p < 0.001); this difference remained significant when adjusted for difference in gender mix. Elective operative mortality rate was significantly lower in EVARmatch (1.9%) than in UKsurveil (5.9%, p < 0.01). Aneurysm-related death rate was two times higher in UKsurveil (1.6/100 patient years) than in EVARmatch (0.8/100 patient years, p = 0.03). All-cause mortality rate was significantly higher in UKsurveil (8.3/100 patient years) than in EVARmatch (6.4/100 patient years, p = 0.02).

CONCLUSIONS

It appears that endovascular repair of small abdominal aortic aneurysms (4.0-5.5 cm) significantly reduces the risk of fatal aneurysm rupture and aneurysm-related death and improves overall patient survival compared to an ultrasound surveillance strategy with selective open surgical repair.

Abdominal aortic aneurysm

Abdominal aortic aneurysms cause 1.3% of all deaths among men aged 65-85 years in developed countries. These aneurysms are typically asymptomatic until the catastrophic event of rupture. Repair of large or symptomatic aneurysms by open surgery or endovascular repair is recommended, whereas repair of small abdominal aortic aneurysms does not provide a significant benefit. Abdominal aortic aneurysm is linked to the degradation of the elastic media of the atheromatous aorta. An inflammatory cell infiltrate, neovascularisation, and production and activation of various proteases and cytokines contribute to the development of this disorder, although the underlying mechanisms are unknown. In this Seminar, we aim to provide an updated review of the pathophysiology, current and new diagnostic procedures, assessment, and treatment of abdominal aortic aneurysm to provide family practitioners with a working knowledge of this disorder.

Telementoring During Endovascular Treatment of Abdominal Aortic Aneurysms:A Prospective Study

PURPOSE

To explore the use of telementoring for distant teaching and training in endovascular aortic aneurysm repair (EVAR).

METHODS

According to a prospectively designed study protocol, 48 patients underwent EVAR: the first 12 patients (group A) were treated at a secondary care center by an experienced interventionist, who was training the local team; a further 12 patients (group B) were operated by the local team at their secondary center with telementoring by the experienced operator from an adjacent suite; and the last 24 patients (group C) were operated by the local team with remote telementoring support from the experienced interventionist at a tertiary care center. Telementoring was performed using 3 video sources; images were transmitted using 4 ISDN lines. EVAR was performed using intravascular ultrasound and simultaneous fluoroscopy to obtain road mapping of the abdominal aorta and its branches, as well as for identifying the origins of the renal arteries, assessing the aortic neck, and monitoring the attachment of the stent-graft proximally and distally.

RESULTS

Average duration of telementoring was 2.1 hours during the first 12 patients (group B) and 1.2 hours for the remaining 24 patients (group C). There was no difference in procedural duration (127+/-59 minutes in group A, 120+/-4 minutes in group B, and 119+/-39 minutes in group C; p=0.94) or the mean time spent in the ICU (26+/-15 hours in group A, 22+/-2 hours in group B, and 22+/-11 hours for group C; p=0.95). The length of hospital stay (11+/-4 days in group A, 9+/-4 days in group B, and 7+/-1 days in group C; p=0.002) was significantly different only for group C versus A (p=0.002). Only 1 (8.3%) patient (in group A: EVAR performed by the experienced operator) required conversion to open surgery because of iliac artery rupture. This was the only conversion (and the only death) in the entire study group (1/12 in group A versus 0/36 in groups B + C, p=0.31).

CONCLUSIONS

Telementoring for EVAR is feasible and shows promising results. It may serve as a model for development of similar projects for teaching other invasive procedures in cardiovascular medicine.

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.

Early outcomes of endovascular versus open abdominal aortic aneurysm repair in the National Surgical Quality Improvement Program–Private Sector (NSQIP–PS)

BACKGROUND

There remains no consensus on the appropriate application of endovascular abdominal aortic aneurysm repair (EVAR). Information from administrative databases, industry-sponsored trials, and single institutions has inherent deficiencies. This study was designed to compare early outcomes of open (OPEN) versus EVAR in a contemporary (2000 to 2003) large, multicenter prospective cohort.

METHODS

Fourteen academic medical centers contributed data to the National Surgical Quality Improvement Program-Private Sector (NSQIP-PS), which ensures uniform, comprehensive, prospective, and previously validated data entry by trained, independent nurse reviewers. A battery of clinical and demographic features was assessed with multivariate analysis for association with the principal study end points of 30-day operative mortality and morbidity.

RESULTS

One thousand forty-two patients underwent elective infrarenal abdominal aortic aneurysm (AAA) repairs: 460 EVAR and 582 OPEN. EVAR patients were older (74 vs 71 years, P < .0001), included more men (84.6% vs 79.6%, P < .05), and had a higher incidence of chronic obstructive pulmonary disease (25.4% vs 17.9%, P < .01). EVAR resulted in significantly reduced overall morbidity (24% vs 35%, P < .0001) and hospital stay (4 vs 9 days, P < .0001). Cardiopulmonary and renal function-related comorbidities had the expected significant impact on mortality for both procedures at univariate analysis ( P < .05). While crude mortality rates between EVAR and OPEN did not differ significantly (2.8% vs 4.0%) ( P = 0.32). After multivariate analysis, correlates of operative mortality included OPEN (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.03 to 5.78; P < .05), advanced age (OR, 1.11; P < .001), history of angina (OR, 5.54; P < .01), poor functional status (OR, 5.78; P < .001), history of weight loss (OR, 7.42; P < .01), and preoperative dialysis (OR, 51.4; P < .0001). EVAR also compared favorably to OPEN (OR, 2.14; 95% CI, 1.58 to 2.89; P < .0001) for overall morbidity.

CONCLUSION

Significant morbidity accompanies AAA repair, even at major academic medical centers. These data strongly endorse EVAR as the preferred approach in the presence of significant cardiopulmonary or renal comorbidities, or poor preoperative functional status.

Colonic epithelial apoptosis during conventional and endoluminal aortic surgery

Background

This study characterized the initial modes of colonic mucosal injury during aneurysm surgery and correlated these with proinflammatory cytokine release into the colonic and systemic circulations.

Methods

Twenty-four patients undergoing conventional open aortic aneurysm repair and ten who had endovascular aneurysm repair (EVAR) were recruited. Mucosal biopsies were taken from the sigmoid colon immediately before and after surgery, for histological examination. Inferior mesenteric vein (IMV) and peripheral blood from patients who had conventional surgery was assayed for interleukin (IL) 1β, IL-6 and tumour necrosis factor (TNF) α. Only peripheral blood from patients who had EVAR was assayed.

Results

Conventional aneurysm repair resulted in a threefold increase in columnar epithelial apoptosis. There was a 26-fold increase in IL-6 in IMV blood within 5 min of reperfusion, with an equivalent rise in peripheral blood after 30 min. A 20-fold rise in peripheral blood TNF-α was observed after surgery. Splanchnic IL-6 correlated positively with cross-clamp time and increased apoptosis. No histological changes were seen after EVAR. There were no intraoperative cytokine changes during EVAR, although a postoperative increase in IL-6 and TNF-α was observed.

Conclusion

The lack of columnar epithelial apoptosis following EVAR reflects the relatively minor ischaemic injury incurred during this procedure.

Blue toe syndrome

The authors report the case of a man with blue toe syndrome, who developed bilateral foot ischemia and underwent successful repair of an abdominal aortic aneurysm and associated renal artery stenosis. Blue toe syndrome is characterized by tissue ischemia secondary to embolization of cholesterol crystals or atherothrombotic debris. Microembolization most often occurs in elderly men who undergo an invasive vascular procedure or have an aneurysm.

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.